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Maize silage based diets for feedlot finishing of Merino lambsBeukes, Johannes Arnoldus 03 1900 (has links)
Thesis (MScAgric)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The aim of the study was to determine the effect of increasing levels of Maize silage in finishing diets for Merino lambs on their feed intake, production performance, feed conversion ratio, digestibility and meat quality. Concerns exist regarding the intake of high moisture and fibre containing silage in sheep due to the physical fill effect thereof. To determine the efficiency of silage as feed ingredient for sheep, maize was cut at 27% dry matter (DM), compacted into 220 litre plastic drums, sealed and left to ferment for 60 days. The silage produced was analysed for fermentation end products and the nutritive value determined. The silage produced had an optimum pH, starch and water soluble carbohydrate (WSC) content. The crude protein (CP) content (112.2 g/kg DM) was higher than expected. Four diets containing, on a dry matter (DM) basis either, 0, 20, 50 or 70% maize silage was formulated on an iso-nutrient basis with exception of neutral detergent fibre (NDF). The aim was to establish the effect of increasing levels of silage on animal production with regard to dry matter intake, growth, digestibility and meat quality. Diets were formulated on an iso-nutrient basis to match the 70% silage diet and therefore had relatively low specifications due to the high inclusion of silage from the 70% silage diet. A growth study and an in vivo and in vitro digestibility study were conducted to determine the effect of the different diets on feedlot sheep production. Meat quality was also determined to establish whether the experimental diets had an effect on meat quality.
Forty lambs in a completely randomised block design, with four treatments, were used in a 60-day finishing study. The dry matter intake (DMI) of lambs decreased as silage inclusion increased above the 20% silage inclusion level. At the 20% inclusion rate, the feed intake of the animals was stimulated. This resulted in significant differences found between the cumulative intake of the low and the high silage diets. Feed conversion ratio (FCR) was poorer, however, for the control and 20% silage diets. The poor FCR most likely was related to the quality of the feed ingredients used in the formulation of the control feed and the concentrate in the 20% silage diet rather than the silage itself. Significant differences were also found in the dressing percentage of the slaughtered animals where the 20 and 50% silage diets had a higher dressing percentage than the control and 70% silage diets. It was concluded that silage can be successfully incorporated into sheep diets, especially at low levels where its inclusion stimulates intake.
Eight animals per group were used in an in vivo digestibility study to determine the apparent digestibility of the experimental diets. Feed, faeces and urine samples collected during the trial period were analysed for the respective nutrients. The 20% diet, even though having the best overall apparent digestibility, did not result in better production responses. Lambs on the 20% silage diet had the highest daily DM intake, which resulted in them having the highest energy intake. There were no differences in total energy excreted between the silage-based diets. This resulted in the 20% silage diet also having the best energy retention. Nitrogen retention was the highest for the control and 20% silage diets. This can be ascribed to the low quality of the concentrate part of the diet. The 20% silage diet, as previously stated, had the highest apparent DM and organic matter (OM) digestibility, while the control diet showed the lowest overall nutrient digestibility. The low nutrient digestibility of the control diet can be ascribed to the relatively poor quality ingredients used. There were no differences in the crude protein (CP) digestibility between the control and the 20% diet. Both proved to be higher than the CP digestibility of the 50 and 70% silage diet. As the neutral detergent insoluble nitrogen (NDIN) was higher for the 50 and 70% diets, this observation was not surprising. Fibre content of the silage-based diets increased as the inclusion level of the silage increased, which resulted in a decrease in overall fibre digestion.
Three cannulated sheep were adapted on each experimental diet for two weeks before rumen fluid was collected for the in vitro digestibility study. No differences between the silage based diets were found for in vitro true digestibility (IVTD). The IVTD of the 20, 50 and 70% diets were higher, however, than the IVTD of the control diet confirming earlier observations on the choice of ingredients used in the control diet to formulate iso-nutrient diets. Degradability coefficients were determined for the DM and NDF fractions of the different experimental diets and fitted to the non-linear model; p = a + b (1 – e-ct). The amount of DM that disappeared in a certain time (t) is represented by p. Constant a represents the fraction that was rapidly soluble, b represents the potential degradable fraction and c is the rate at which b was degraded. There were no differences between experimental diets for the rapidly soluble fraction. The silage-based diets had a higher potential degradable fraction (b) but did not differ in the degradability rate (c) from the control diet. Silage-based diets had higher overall effective degradability than the control but did not differ between one another. Constant a was not determined for NDF degradability since the NDF fraction did not have a rapidly soluble fraction. The control diet had the lowest potential degradable NDF fraction with the rate also being lower than the silage based diets. Effective NDF degradability was highest for the 50% silage diet.
Lambs used in the finishing study were slaughtered and meat samples taken for meat quality tests. The pH, colour, drip loss, cooking loss, shear force and fatty acid composition were determined on the Longissimus dorsi samples collected at Roelcor (Malmesbury, Western Cape, South Africa). Proximate analysis was also conducted on the meat samples. The experimental diets did not have a significant effect on the proximate chemical composition of the meat. Colour differences were found; however no clear pattern could be established. There were no differences in fatty acid composition. It can be concluded that up to 70% maize silage can be included in the finishing diets of Merino lambs with no adverse effects on the meat quality.
The study showed that 20% maize silage can be included in the finishing diets of Merino lambs without negatively affecting intake, production, digestibility or meat quality. Future research is needed to optimise the 20% silage diet, however, and to again look at the effect that it will have on animal production, including the effect thereof on total methane emissions. / AFRIKAANSE OPSOMMING: Die doel van die studie was om te bepaal of mielie kuilvoer doeltreffend gebruik kan word as ‘n komponent in die afronding van Merino lammers. Gedurende die proses is mielies gesny teen 27% droë materiaal (DM), en saamgepers in 220 liter plastiek dromme. Dit is toegelaat om te fermenter vir 60 dae. Die kuilvoer wat daaruit geproduseer is, is geanaliseer vir fermentasie eindprodukte, en die voedingstofwaarde is bepaal. Vier diëte met onderskeidelik 0 (kontrole), 20, 50 en 70% kuilvoer is geformuleer op ‘n iso-nutriëntbasis met die uitsondering van vesel (NDF). ‘n Groeistudie, tesame met ‘n in vivo en in vitro verteerbaarheidstudie is uitgevoer om die effek van die verskillende diëte op diere produksie te toets. Vleiskwaliteit toetse is ook gedoen om te kyk of die verskillende diëte ‘n effek op vleiskwaliteit het.
Veertig lammers, in ‘n ewekeurige blokontwerp, is gebruik in ‘n 60 dae afrondingstudie. Dit is opgemerk dat die DM inname (DMI) afgeneem het soos die kuilvoer insluiting bo die 20% vlak toegneem het. By die 20% insluitingskoers, is voerinname by die diere gestimuleer. Dit het veroorsaak dat beduidende verskille gevind is tussen die kumulatiewe inname van die lae en die hoë kuilvoer diëte. Die voeromsetkoers (VOK) was egter hoër vir die kontrole en 20% kuilvoer diëte. Beduidende verskille is ook gevind in die uitslagpersentasie van die diere, waar die 20% en 50% kuilvoer diëte ‘n hoër uitslagpersentasie as die kontrole en 70% kuilvoer diëte gehad het.
Agt diere is per groep gebruik in ‘n in vivo verteerbaarheidstudie om die skynbare verteerbaarheid van die eksperimentele diëte te toets. Voer, feses en urien monsters is gedurende die proefperiode ingesamel en geanaliseer. Die 20% kuilvoer dieet het die hoogste DM en organiese materiaal skynbare verteerbaarheid teenoor die kontrole diet wat die laagste gehad het. Daar was geen verskille in die ru- proteien (RP) verteerbaarheid van die kontrole en 20% kuilvoer diet nie. Beide was hoër as die RP verteerbaarheid van die 50% en 70% kuilvoer dieet. Die veselinhoud van die kuilvoergebasseerde diëte het toegeneem soos die insluitingsvlak van die kuilvoer toegeneem het, wat ‘n afname in veselvertering veroorsaak het. Lammers op die 20% kuilvoer dieet het die hoogste daaglikse DM inname gehad, wat die hoogste energie inname tot gevolg gehad het. Daar was geen verskille in die totale energie inname van die kuilvoergebasseerde diëte – dit het veroorsaak dat die 20% kuilvoer dieet ook die beste energie retensie gehad het. Stikstof retensie was die hoogste vir die kontrole en 20% kuilvoer dieet.
Drie gekannuleerde skape is vir twee weke op elke eksperimentele dieet aangepas voordat rumenvloeistof ingesamel is vir die in vitro verteerbaarheidstudie. Geen verskille is gevind vir die in vitro ware verteerbaarheid (IVWV) tussen die kuilvoergebasseerde diëte nie. Hulle was egter hoër as die IVWV van die kontrole dieet. Degradeerbaarheid koëffisiënte is bepaal vir die DM en NDF fraksies van die verskillende eksperimentele diëte en is gepas in die model p = a + b (1 – e-ct). Die hoeveelheid DM wat verdwyn het binne ‘n sekere tyd (t) word voorgestel deur p. Die konstante a verteenwoordig die fraksie wat vinnig oplosbaar is, b verteenwoordig die potensieel degradeerbare fraksie en c is die koers waarteen b gedegradeer is. Konstante a is nie bepaal vir die NDF degradeerbaarheid nie, aangesien die NDF fraksie nie ‘n vinnig oplosbare fraksie gehad het nie. Daar was geen verskille in die vinnig oplosbare fraksie tussen eksperimentele diete nie. Kuilvoer gebasseerde diete het ‘n hoër potensieel degradeerbare fraksie gehad, maar daar was geen verskille in koers van degradering nie. Die kuilvoergebasseerde diëte het ‘n hoër DM effektiewe degradeerbaarheid as die kontrole dieet. Effektiewe NDF degradeerbaarheid was die hoogste vir die 50% kuilvoer dieet. Lammers in die studie gebruik is geslag en vleismonsters is geneem vir vleiskwaliteit toetse, insluitende pH, kleur, drupverlies, kookverlies en taaiheid. Proksimale analise is ook uitgevoer op die vleismonsters. Die eksperimentele diëte het nie ‘n beduidende effek op die proksimale chemiese samestelling van die vleis gehad nie. Kleur verskille is wel gevind, maar geen duidelike patroon kon vasgestel word nie. Daar was geen verskille in die vetsuur samestelling nie. Daar kan dus tot die gevolgtrekking gekom word dat mielie kuilvoer ingesluit kan word in die afrondingsdiëte van Merino lammers, tot by 70%, sonder enige negatiewe effekte op die vleiskwaliteit.
Daar is tot die gevolgtrekking gekom dat mielie kuilvoer suksesvol geïnkorporeer kan word in skaapdiëte, veral teen lae vlakke (20%) waar die gebruik nie net inname stimuleer nie, maar ook geen negatiewe effekte het op produksie en verteerbaarheid nie. / Dr. Francois van de Vyver, Cape Wools and NWGA for providing funding in the form of post graduate bursaries
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Enhancing the breed analysis of the Dohne Merino by accounting for heterogeneous variances and phantom parentsJordaan, Wilmari 12 1900 (has links)
Thesis (MScAgric)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Genetic (co)variances for body weight, clean fleece weight and fibre diameter were estimated for the South African Dohne Merino using data transformed as proportions of contemporary group means. The data analysed included body weight, clean fleece weight and fibre diameter records for 282 513 animals, evaluated between 1992 and 2011. There were 5 698 sires, 105 886 dams and 6 291 contemporary groups in the data. A three-trait animal model was fitted, where the random variables were the direct additive genetic effects, as well as the sire-flock-season (SFS) interaction, while the fixed effects included contemporary groups (FYSSM) (6 291 classes), birth status (single, twins or triplets), age of dam (1 to 3 years), which was plotted as a linear regression as well as age at performance measurement, which was fitted as a polynomial.
The direct heritability estimates (SE) for body weight, clean fleece weight and fibre diameter were 0.265 (0.005), 0.210 (0.004) and 0.437 (0.005), respectively. Genetic correlations for body weight with clean fleece weight and fibre diameter were 0.035 (0.015) and 0.139 (0.011), respectively, while the genetic correlation between clean fleece weight and fibre diameter was 0.169 (0.012). Body weight had phenotypic correlations of 0.327 (0.002) and 0.150 (0.002), respectively, with clean fleece weight and fibre diameter, which had a phenotypic correlation of 0.190 (0.002) with clean fleece weight. The moderate to high heritability estimates suggests that there is substantial genetic variation, which may result in genetic improvement if selection is applied on these traits. Genetic correlations were generally low, suggesting that progress in all these traits was possible in a scientific selection program. Genetic trends derived during the study supported the contention that genetic progress in all traits was attainable in a well-constructed breeding programme.
Transformation of the data to percentages of contemporary groups resulted in adjustments to breeding values. The breeding values for sires originating from flocks maintained in limiting environments (Low group; 180 sires) were adjusted upwards, while those of sires originating from a non-limiting production environment (High group; 146 sires) were adjusted downwards. These effects were markedly obvious for the quantitative traits (body weight and clean fleece weight), but to a much lesser extent for fibre diameter. This transformation resulted in the genetic trends for the Low groups being adjusted to be comparable to those in the High group for body weight and Fibre diameter. It was concluded that sire breeding values derived from transformed data would be more robust across the typical diverse environments supporting local Dohne Merino production. The genetic value of animals entering the recorded population from a commercial base (F4 animals) was below the fully recorded part of the population. The inclusion of phantom parent groups in the genetic analysis rendered genetic trends in F4 animals comparable to that of the pedigreed portion of animals in the analyses. It was concluded that animals from a commercial base (which are alleged to have advantages in terms of fitness and robustness) were more likely to perform satisfactorily for selection with the inclusion of phantom groups than without it. It was recommended that data in the national Dohne Merino analysis be transformed proportion of contemporary group means to account for heterogeneous contemporary group variances. Phantom parent groups should also be applied to the analysis to increase the probability of those animals entering the breeding flock from a commercial base being selected. / AFRIKAANSE OPSOMMING: Genetiese kovariansies vir liggaamgewig, skoonvaggewig en veseldikte is vir die SA Dohne Merino bevolking in Suid-Afrika beraam nadat data getransformeer as ‘n proporsie van die kontemporêre groep gemiddelddes uitgedruk is. Die data het rekords in van liggaamsgewig, skoonvaggewig en veseldikte van 282 513 diere oor die tydperk van 1992 tot 2011 ingesluit. Die data sluit rekords van 5 698 vaars, 105 886 moers en 6 291 kontemporêre groepe in. 'n Meer-eienskapdieremodel met 'n additiewe diere-effekte sowel as 'n vaar-kudde-seisoen (SFS) interaksie is as ewekansige effekte gemodelleer, bykomstig tot die vaste effekte van kontemporêre groep (FYSSM) (6 291 klasse), geboortestatus (enkelling, tweeling of drieling), ouderdom van moer (1 tot 3 jaar) gepas as 'n lineêre regressive, sowel as ouderdom by prestasie meting as ‘n polinoom gepas.
Die beraamde direkte oorerflikheid (SF) van liggaamgewig, skoonvaggewig en veseldikte van die meereienskap dieremodel was onderskeidelik 0,265 (0,005), 0,210 (0,004) en 0,437 (0,005). Die genetiese korrelasies van liggaamsgewig met skoonvaggewig en veseldikte was 0,035 (0.015) en 0,139 (0.011) onderskeidelik, terwyl die genetiese korrelasie tussen skoonvaggewig en veseldikte 0,169 (0.012) beloop het. Liggaamsgewig het onderskeie fenotipiese korrelasies van 0,327 (0.002) en 0.150 (0.002) met skoonvaggewig en veseldikte gehad, terwyl skoonvaggewig ‘n fenotipiese korrelasie van 0.190 (0.002) met veseldikte gehad het. Die medium tot hoë oorerflikheidhede dui daarop dat daar aansienlike genetiese variasie voorkom, wat kan aanleiding gee tot genetiese vordering as seleksie op die eienskappe toegepas word. Genetiese korrelasies was oor die algemeen laag wat daarop dui dat vordering in al die eienskappe deur ‘n wetenskaplike seleksie program moontlik is. Die aanspraak is deur genetiese tendense in die studie bevestig.
Die transformasie van data na proporsies van kontemporêre groep gemiddeldes het daartoe gelei dat teelwaardes aangepas word. Die teelwaardes van vaars uit kuddes met ‘n omgewing wat beperk word (Lae groep:180 vaars), is opwaarts aangepas. Daarenteen is vaars uit 'n nie-beperkende produksie omgewing (Hoë groep:146 vaars) se teelwaardes afwaarts aangepas. Hierdie effekte was veral ooglopend vir die kwantitatiewe eienskappe, liggaamgewig en skoonvaggewig, maar tot 'n mindere mate vir veseldikte. Die transformasie het daartoe gelei dat die genetiese tendense for die Lae groep aangepas word om vergelykbaar te wees met die Hoë groep vir liggaamsgewig en skoonvaggewig. Die gevolgtrekking was gemaak dat meer toepaslike vaar teelwaardes, bereken vanaf getransformeerde data, verkry word vir regoor die diverse omgewings wat produksie van plaaslike Dohne Merinos ondersteun. Die genetiese waarde van diere wat die aangetekende populasie uit ‘n kommersiële agtergrond (F4 diere) binnekom was laer as die volledig aangetekende gedeelte van die populasie. Die insluiting van skimgroepe in die genetiese ontleding het tot genetiese tendense gelei wat die F4 diere vergelykbaar gemaak het met diere in die ontleding wat wel stamboekinligting het. Die gevolgtrekking is gemaak dat diere van ‘n kommersiële agtergrond (wat aanvaar word om voordele in te hou in terme van fiksheid en robuustheid) meer geredelik geselekteer sal word vir die stoet met die insluiting van skimgroepe as daarsonder.
Dit word aanbeveel dat die data in die Nasionale Dohne Merino na proporsies van die kontemporêre groepgemiddeldes getrensformeer word om vir heterogene kontemporêre groep variansies voorsiening te maak. Skimgroepe moet ook gepas word in die ontleding om die waarskynlikheid te verhoog dat diere vanuit 'n kommersiële basis, ook geselekteer sal word.
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Comparison of production parameters and meat quality characteristics of South African indigenous chickensPackard, Russel 04 1900 (has links)
Thesis (MScAgric)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: This study quantified the growth performance, carcass and meat characteristics of South
African slow-growing chicken lines. Two slow-growing lines developed outside South Africa,
the Black Australorp and New-Hampshire, two native lines including the Naked-Neck and
Potchefstroom Koekoek, as well as a hybrid between a Cobb 500 broiler and Potchefstroom
Koekoek were evaluated. Fifty birds of each line were randomly allocated to cages of five
birds per cage where they were fed a standard broiler diet ad libitum to an average weight of
2kg. Twenty cockerels of each line were then slaughtered for further analyses. For the
carcass characteristics: live weight at slaughter, hot carcass weight, and chilled carcass
weight were determined. Portion yields and dissection characteristics were measured, and
the deboned meat from the breast, thigh and drumstick analysed for proximate analysis and
fatty acids.
Average daily gain (ADG), feed conversion ratio (FCR), and European Production Efficiency
Factor (EPEF) were calculated and analyzed for line differences. No significant differences
were observed between the indigenous lines with regards to feed intake ADG (~22g), FCR
(~3.65), and EPEF (~57). The Hybrid outperformed the indigenous lines for all of the growth
performance parameters measured. No differences were observed for dressing %. The breast yield obtained by the Hybrid was
significantly higher (45.56%) than that of the indigenous lines which had similar breast yield
values (~41%). The naked-Neck had the highest thigh yield and the lowest drumstick
percentage yield, 27.7% and 17.3%, respectively. A similar pattern was observed for
drumstick yield with the Australorp, New-Hampshire and Koekoek lines having significantly
higher yields than those of the Hybrid. For the tissue characteristics, similar values were
seen for breast skin (~20%), breast bone (~22%), drumstick skin (~4.3%), and drumstick
muscle (~27%). The Hybrid had significantly higher breast muscle, thigh muscle, and total
muscle percentage yield (22.67%, 26.17% and 43.51%, respectively).
Proximate chemical composition of the breast samples did not differ (P>0.05) for any
parameters. Differences (P<0.05) were recorded for thigh moisture, protein and ash
content. The Naked-Neck recorded the lowest moisture (72.3%) and the highest protein
(18.6%) and ash (1.1%) values. Differences were also recorded for drumstick moisture
protein and fat. The highest moisture content was measured for the Hybrid (75.9%) and the
lowest for the Naked-Neck (73.6%). The indigenous lines had higher protein content
(~19.5%) when compared to the Hybrid (18.9%). The drumstick fat content for the Nakednecks
(4.4%) was higher than the remaining lines. Differences were observed for the fatty acid profile. Total PUFA differed (P<0.05) with the
Australorp (28.2%) showing the highest proportion. The relative contributions of total SFA,
total MUFA and TUFA did not differ significantly between lines. The ratio of polyunsaturated
and saturated fatty acids, the proportion of n-6 fatty acids and the ratio of n-6/n-3 differed,
higher values were recorded for the indigenous lines. The proportion of n-3 fatty acids did
not differ.
The Hybrid performed significantly better than the indigenous lines but did not reach the
performance potential expected for commercial broilers. Despite this, the Hybrid does show
potential for use in alternative practices that make use of slower growing lines. / AFRIKAANSE OPSOMMING: Hierdie studie het die groei-prestasie, karkas- en vleiskwaliteitseienskappe van Suid
Afrikaanse inheemse hoenders gekwantifiseer. Vier plaaslike lyne, die Swart Ostralorp, New
Hampshire, Kaalnek en Potchefstroomse Koekoek, sowel as ʼn kruising van die Koekoek
henne met Cobb 500 braaikuikenhane is evalueer. Vyftig voëls van elke genotipe is
ewekansig ingedeel in hokke met vyf voëls per hok. ʼn Standaard braaikuiken dieet is
gevoer totdat die gemiddelde massa van die kuikens 2kg bereik het. Daarna is 20 hane van
elke genotipe geslag vir verdere analise. Vir karkaseienskappe is lewendige massa voor
slag, warm karkasmassa en koue karkasmassa bepaal. Daarna is porsie opbrengs en
disseksie eienskappe bepaal en, en die ontbeende vleis van die bors, dy en been is ontleed
vir proksimale en vetsuur analises.
Gemiddelde daaglikse toename (GDT), voeromsetverhouding (VOV), en Europese
produksie effektiwiteits faktor (EPEF) is vir die verskillende genotipes bereken en getoets vir
verskille. Geen betekenisvolle verskille is waargeneem vir inname, GDT (~22g), VOV
(~3.65), en EPEF (~57) nie. Die kruisras het in alle gevalle beter produksieparameters
gelewer as die plaaslike lyne. Geen verskille is opgemerk vir uitslagpersentasie nie. Die borsopbrengs van die kruisras
was betekenisvol hoër (45.66%) as die van die plaaslike lyne (~41%). Die Kaalnek het die
hoogste dyopbrengs (27.7%) en die laagste beenopbrengs (17.3%) gelewer. ʼn Soortgelyke
patroon is waargeneem vir die beenopbrengs van Australorp, New-Hampshire en Koekoek
met betekenisvol hoër opbrengste as dié van die kruisras. Weefsel eienskappe het
dieselfde opbrengs gelewe vir die plaaslike lyne met borsvel (~20%), borsbeen (~22%),
beenvel (~4.3%) en beenspier (~27%). Die kruisras het betekenisvol meer borsvleis,
dyspier en totale spierpersentasie gelewer as al die ander genotipes (onderskeidelik
22.67%, 26.17% en 43.51%). Proksimale analise van die borsmonsters het geen verskille (P>0.05) gelewer vir enige van
die parameters wat bepaal is nie. Verskille is opgemerk vir die vog-, proteïen- en asinhoud
van die dyspier. Die Kaalnek het die laagste voginhoud (72,3%) en die hoogste
proteïen- (18.6%) en as-inhoud (1.1%) gehad. Verskille is ook opgemerk vir been vog-,
proteïen- en vetinhoud. Die hoogste voginhoud is gemeet in die kruisras (75.9%) en die
laagste in die Kaalnek (73.6%). Die plaaslike lyne het ʼn hoër proteïeninhoud (~19.5%) as
die kruisras (18.9%) gehad. Die vetinhoud van die beenspier was ook die hoogste vir die
Kaalnek (4.4%).
Verskille is waargeneem vir die vetsuurprofiele van vleis. Die PUFA het verskil, met die
hoogste persentasie waargeneem vir die Australorp (28.2%). Die verhoudelike bydrae van
die totale SFA, totale MUFA en TUFA het nie betekenisvol tussen genotipes verskil nie. Die
verhouding van n-3 vetsure het ook nie verskil nie. Die verhouding van die PUFA:SFA, die
verhouding van n-6 vetsure en die verhouding van n-6/n-3 vetsure het verskil, met hoër
waardes vir die plaaslike lyne. Die verhouding van n-3 vetsure het nie verskil nie.
Die kruisras het oor die algemeen betekenisvol beter gevaar as die plaaslike lyne, maar het
steeds nie die produksie potensiaal van die kommersiële braaikuiken bereik nie.
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Specialized feeding of lambs for optimized performance during the finishing phaseMoolman, Justin 04 1900 (has links)
Thesis (MScAgric)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The aim of this study was to determine whether a lamb finishing ration that is
balanced for essential amino acids (EAA), at a specific level of non-structural
carbohydrates (NSC) would yield better feedlot performance when compared to a
standard commercial finishing ration.
Metionine (Met) and Lysine (Lys) were identified as the first limiting amino acids for
growing lambs. These two amino acids, as well as Threonine (Thr), Arginine (Arg),
Leucine (Leu), Isoleucine (Ile) and Phenylalanine (Phe) were included in an
optimized protein (OP) feedlot ration at optimal levels. This ration was formulated to
contain 157 g/kg crude protein (CP) and 477 g/kg NSC, with Met, Lys, Arg and Thr at
2.48, 7.45, 8.51 and 8.12 g/kg on dry matter (DM) basis respectively. The second
treatment, FIN, was a standard commercial lamb finishing feed without optimized
amino acids and contained similar total protein and NSC to OP of 152 g/kg CP and
468 g/kg NSC but with Met, Lys, Arg and Thr at 2.08, 5.49, 7.47 and 4.80 g/kg on
DM basis respectively. A third treatment, a low protein (LP) diet served as a positive
control and was formulated on lower specifications (139 g/kg CP, 455 g/kg NSC) and
was also not optimized for amino acids. This treatment contained Met, Lys, Arg and
Thr at 1.93, 4.99, 6.66 and 4.73 g/kg on DM basis respectively. Lambs grazing
kikuyu pasture served as the negative control (CON) group. These lambs also
received additional supplementary feed at 500 g/day as a production lick to be
comparable to a scenario where lambs are finished on grazing. Forty cross-bred Merino x Döhne-Merino lambs with an average weaning weight of
24.35 ± 0.648 kg were finished in a feedlot for 57 days where after they were
slaughtered at an average weight of 41.41 ± 1.259 kg. During the feedlot trial lamb
performance was measured by monitoring daily growth rates and feed intake. Also,
an in vivo digestibility study was carried out on the OP and FIN lambs. During the
slaughter process the rumen was removed which was done to collect a sample of
the rumen wall from next to the rumino-reticular fold. These rumen samples were
mounted onto slides so that the development of the rumen could be examined. The M. longissimus dorsi from both sides of the carcass between the 2nd and 3rd last
thoracic vertebra and the 4th and 5th lumbar vertebra were removed.
There was no significant difference (P > 0.05) between any of the concentrate feed
treatments with regards to the average daily gain (ADG), feed conversion ratio (FCR)
or dressing percentage (DP). The CON lambs, as expected, had lower growth rates
(P < 0.05) than the concentrate fed lamb and thus showed significant differences (P
< 0.05) in terms of ADG. The DP of 45.96 % ± 0.711 for the CON lambs differed
significantly (P < 0.05) from the OP (51.44 % ± 0.358), FIN (52.72 % ± 0.653) and LP
(51.74 % ± 0.611) treatments. As expected the concentrate feeds were much more
effective in maintaining higher growth rates when compared to the CON lambs while
the optimizing of EAA in the OP diet did not lead to improved feedlot performance as
the FIN and LP treatments were able to achieve similar (P > 0.05) growth rates.
Within the feedlot treatments there was no significant difference (P > 0.05) with
regard to the papillae length and rumen wall thickness. There was however a
numerical increase in the papillae length as the NSC levels in the feed increased.
The CON lambs differed from the OP lambs (P < 0.05) in terms of papillae length.
This illustrated the importance of having increased levels of NSC in a feedlot diet as
it is this fraction that is responsible for the initialisation and maintenance of rumen
morphological development. The in vivo digestibility study therefore confirmed that the commercial finishing feed
was just as effective as the optimized feed in terms of nitrogen retention as well as in
maintaining suitable energy balance. Although the in vivo digestibility for Met and Lys
in the OP feed was higher (P < 0.05) than the FIN feed, this did not lead to improved
feedlot performance of the OP lambs. The increased digestibility of these amino
acids is due to the fact that the OP diet was higher in levels of bypass amino acids
than the FIN feed. The in vitro true digestibility (IVTD) of the OP feed was higher (P < 0.05) than that of the FIN feed. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om te bepaal of ‘n lamafrond rantsoen wat
gebalanseerd is vir beperkende essiensiële aminosure (EAA) teen ‘n spesifieke vlak
van nie-strukturele koolhidrate (NSK) beter voerkraal prestasie teweeg sou bring
wanneer gemeet word teen ‘n standaard kommersiële afrond rantsoen.
Metionien (Met) en Lisien (Lis) is geïdentifiseer as die eerste beperkende aminosure
vir groeiende lammers. Hierdie twee aminosure, asook Treonien (Tre), Leusien
(Leu), Isoleusien (Ile) en Fenielalanien (Fen) is teen optimale vlakke ingesluit in ‘n
geoptimeerde voerkraal rantsoen, OP. Hierdie rantsoen is geformuleer om 157 g/kg
RP en 477 g/kg NSK te bevat asook Met, Lis, Arg en Tre teen 2.48, 7.45, 8.51 en
8.12 g/kg onderskeidelik. Die tweede behandeling, FIN, was ‘n kommersiële
lamafrond voer waarin die aminosure nie geoptimeer is nie en het soortgelyke vlakke
van proteïene en NSK bevat teen 152 g/kg RP en 468 g/kg NSK met Met, Lis, Arg
en Tre teen 2.08, 5.49, 7.47, 4.80 g/kg onderskeidelik. ‘n Derde voer, LP, het gedien
as ‘n positiewe kontrole en was ‘n lae proteïen voer met laer spesifikasies (139 g/kg
RP, 455 g/kg NSK) waarin die aminosure ook nie geoptimeer is nie. Die LP voer het
Met, Lis, Arg en Tre bevat teen 1.93, 4.99, 6.66 en 4.73 g/kg onderskeidelik. Die
negatiewe kontrole behandeling, CON, is verteenwoordig deur lammers wat op
kikuyu gewei het terwyl addisionele supplementêre voeding teen 500g/lam/dag
voorsien is. Hierdie supplementêre voeding het gedien as ‘n produksie lek om
sodoende vergelykbaar te wees met scenario waar lammers op weiding afgerond word. Veertig kruisgeteelde Merino x Döhne-Merino lammers met ‘n gemiddelde gewig van
24.35 ± 0.648 kg is vir 57 dae in ‘n voerkraal afgerond waarna hulle, teen ‘n
gemiddelde gewig van 41.41 ± 1.259 kg, geslag is. Tydens die voerkraal proef is
prestasie gemonitor deur die meet van daaglikse groei en voerinname. Hiertydens is
daar ook ‘n in vivo verteringsproef op die OP en FIN lammers gedoen. Tydens die
slagproses is die rumen verwyder waarna ‘n monster van die rumenwand langs die
rumino retikulêre vou geneem is. Hierdie rumenmonsters is op skyfies geplaas sodat
die ontwikkeling van die rumen ondersoek kan word. Die M. longissimus dorsi was aan beide kante van die karkas tussen die 2de en 3de laaste torakale werwels en
die 4de en 5de lumbale werwels verwyder.
Daar was geen betekenisvolle verskille (P > 0.05) tussen enige van die konsentraat
behandelings ten opsigte van gemiddelde daaglikse toename (GDT), voeromset
verhouding (VOV) of uitslag persentasie nie. Die CON lammers het egter, soos
verwag, beduidend (P < 0.05) stadiger gegroei en het dus verskille getoon ten
opsigte van GDT. Die uitslag persentasie van 45.96 % ± 0.711 vir die CON lammers
het ook betekenisvol verskil (P < 0.05) van die OP (51.44 % ± 0.358), FIN (52.72 %
± 0.653) en LP (51.74 % ± 0.611) behandelings.
Binne die voerkraal behandelings was daar geen betekenisvolle verskille (P > 0.05)
ten opsigte van die papillae lengte en rumenwand dikte nie, alhoewel daar ‘n
numeriese toename in papillae lengte was soos die NSK vlakke in die voer gestyg
het. Die CON lammers het wel van die OP lammers verskil (P < 0.05) ten opsigte
van papillae lengte. Hierdie bevinding het bevestig hoe belangrik NSK is in die
inisiasie en instandhouding van die morfologiese ontwikkeling van die rumen. Die in vivo verterings studie het daarop gedui dat die kommersiële afrond voer net so
effektief soos die geoptimeerde voer was in terme van stikstof retensie asook die
handhawing van ‘n geskikte energie balans. Alhoewel die in vivo verteerbaarheid
van Met en Lis in die OP hoër was (P < 0.05) as in die FIN voer, het hierdie verskille
nie gelei tot beter groei in die OP lammers nie. Hierdie verskil in verteerbaarheid is
toegeskryf aan die feit dat die aminosure in die OP voer meer rumen-beskermd was
as dié in die FIN voer. Die in vitro verteringstudie het daarop gedui dat die OP voer
beduidend beter (P < 0.05) verteer is as die FIN voer.
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The influence of genotype on sperm motility and sperm head morphometry of Merino (Ovis aries) sheepBoshoff, Ninja Hettie 04 1900 (has links)
Thesis (MScAgric)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The application of assisted reproductive biotechnologies in sheep flocks is hampered by the
susceptability of ovine sperm to cryodamage. There is still considerable scope in the
improvement of cryopreservation protocols for ovine sperm to minimize the degree of damage
to sperm during the cryopreservation process. Pre-cryopreservation processing has a definite
effect on the survivability, motility, and fertilizing ability of sperm. Little information is however
available on the potential contribution of the genetic make-up of rams, divergently selected for
fecundity, on the ability of sperm to offer resistance to the damage caused by cooling,
cryopreservation and thawing. The study aimed to investigate the influence of genetic selection
for prolificacy (i.e. High Merino Line and Low Merino Line in terms of fecundity) on the ability of
ovine sperm to offer resistance to cryodamage.
The study investigated the effect of pre-cryopreservation processing by comparing motility and
morphometry traits recorded for fresh- and post-thaw Merino ejaculated and epididymal sperm
samples obtained form the High and Low lines, respectively. The effect of different sperm
concentrations, equilibration periods and the addition or omission of seminal plasma from
cryopreserved samples on the viability and morphometrical traits were also investigated.
Ejaculate samples were collected by means of the artificial vagina (AV) method from 8 High
Line rams and 7 Low Line rams. Epididymal samples were collected from 6 rams of each of the
High and Low lines respectively, by recovering the epididymal sperm via aspiration from the
cauda epididymides post mortem. Ejaculate samples were subjected to macroscopic and
microscopic evaluation, and epididymal samples only to microscopic evaluation, for which the
Sperm Class Analyzer® program was used for the evaluation of motility and morphometric
measurements. Sperm motility recordings were captured at 100 frames per second. From findings of the study, it was concluded that genotype had no positive influence on the
conception rate of the ewes mated to the High or Low Line rams, even though the rams from
the two lines differed significantly in terms of their serving capacity. When sperm morphometry
was evaluated for fresh ejaculate samples, the two lines differed significantly in terms of the
morphometric traits elongation and ellipticity. Epididymal and ejaculated sperm obtained from
Low Line rams had broader and rounder heads, compared to sperm obtained from High Line
rams. When morphometry was assessed for sperm samples between the two methods of sperm
recovery (collected with an AV or recovery via aspiration from the cauda epididymides of
sacrificed rams), no morphometrical differences were observed. Significant differences were
reported for the majority of the sperm motility traits (i.e. percentage motile, rapid-, medium-,
slow swimming, curvilinear velocity (VCL), straight line velocity (VSL), average path velocity (VAP), and amplitude of the lateral head displacement (ALH)) recorded for ejaculated and
epididymal sperm. The motility traits ALH and beat-cross frequency (BCF) analysed for
epididymal sperm differed significantly between the two lines. When epididymal sperm were
evaluated post-thaw, it became evident that the sperm obtained from the High Line rams had a
larger acrosome surface cover when compared to that of the Low Line ram sperm. The addition
of seminal plasma to epididymal samples did not result in an improvement of the preservation of
sperm motility. It is known from the literature that cryopreservation causes a decrease in sperm
head size. Head width was unaffected by cryopreservation with the addition of seminal plasma
in this study, indicating a potential benefit with the use of seminal plasma in the
cryopreservation protocol of epididymal ram sperm.
The study compared two pre-processing techniques, i.e. the more time consuming swim-up
technique (SUT) with a more time-efficient ‘flush technique’ (FT) to optimize the pre-processing
protocol for motility assessment of sperm samples before cryopreservation of ram sperm.
Comparison of the SUT and FT indicated that almost all of the motility parameters measured
using the FT compared favourably with those obtained using the SUT. The results indicated that
the FT can be used a more time-efficient technique to use for determining the motility of a
sperm sample prior to cryopreservation.
In conclusion, line differences associated with reproduction were observed in terms of the
serving capacity of the rams, with selection for fecundity influencing the morphometric traits
elongation and ellipticity for sperm obtained from the two lines. Future studies should be aimed
at investigating morphometric traits of ovine sperm, to correlate it with fertilizing ability of sperm
post-thaw and ensure optimal cryopreservation processing. / AFRIKAANSE OPSOMMING: Die toepassing van ondersteunende reproduksie tegnieke in skaaptroppe word bemoeilik deur
die onvermoë van ram sperme om weerstand teen bevriesingskade te bied. Daar is nog baie
ruimte vir die verbetering van die bevriesingsprotokolle vir skaap sperm om die omvang van
bevriesingskade te verminder. Voor-bevriesing verwerking het dan 'n besliste uitwerking op die
oorlewing, beweeglikheid en bevrugtingsvermoë, van skaap sperme. Min inligting is beskikbaar
oor die potensiële bydrae van die genetiese samestelling van ramme wat uiteenlopend op
grond van vrugbaarheid geselekteer is, op die vermoë van skaap sperme om weerstand te bied
teen die skade wat deur verkoeling, diepbevriesing en ontdooiing, veroorsaak word. Die doelwit
van die studie was om die invloed van genetiese seleksie vir fekunditeit (d.i. Hoë Merino Lyn en
Lae Merino Lyn in terme van fekunditeit) op die vermoë van skaap sperme om weerstand teen
bevriesingskade te bied, te ondersoek.
Die studie het getoets wat die bevriesing proses se effek op epididimale sperme is, deur sperm
motiliteit en -morfometrie te vergelyk tussen vars gekollekteerde sperme en sperm monsters na
ontdooiing. Die effek van verskillende sperm konsentrasies, ekwilibrasie tydperke en die
byvoeging of uitsluiting van seminale plasma op die lewensvatbaarheid en morfometriese
eienskappe van Merino ramsperme is ondersoek in die studie. Geëjakuleerde monsters is
versamel met behulp van 'n kunsmatige vagina (AV) van 8 Hoë Lyn en 7 Lae Lyn ramme.
Epididimale monsters is verkry van 6 ramme van elk van die Hoë en Lae Lyne, deur middel van
aspirasie van die sperme uit die cauda epididimii nadoods. Geëjakuleerde sperm monsters is
met behulp van makroskopiese en mikroskopiese metodes geëvalueer, en epididimale sperm
monsters slegs mikroskopies geëvalueer, met behulp van die Sperm Class Analyzer® program
wat vir die evaluasie van beweeglikheid en morfometriese afmetings gebruik is. Sperm
beweeglikheids opnames is opgeneem teen 100 raampies per sekonde. Die resultate van die studie het aangedui dat genotipe geen effek het op besetting van die ooie
gepaar met die Hoë of Lae Lyn ramme gehad het nie, terwyl die dekvermoë aansienlik tussen
ramme van die twee lyne verskil het. Wanneer die morfometriese eienskappe van vars
geëjakuleerde sperme vergelyk was, het die lyne beduidend in terme van die morfometriese
eienskappe van verlenging (elongation) en elliptisiteit verskil het. Die epididimale en
geëjakuleerde sperme verkry vanaf die Lae Lyn ramme het ʼn breër en ronder kopvorm getoon
as sperme wat verkry is van die Hoë Lyn ramme. Wanneer die morfometriese eienskappe van
sperme versamel met die twee verskillende metodes (d.i. kunsmatige vagina of aspirasie vanuit
die cauda epididimides) vergelyk was, is geen morfometriese verskille waargeneem nie. Die
meeste sperm beweeglikheidseienskappe (d.i. persentasie beweeglike, vinnig-, medium- en
stadig-swemmende sperme, VCL, VSL, VAP en ALH) van geëjakuleerde en epididimale sperme het verskil. Die beweeglikheidseienskappe amplitude van die laterale verplasing van die
spermkop (ALH) en frekwensie waarmee sperm sy eie pad kruis (BCF), soos bepaal vir
epididimale sperme, het beduidend tussen die twee lyne verskil. Met die evaluering van
epididimale sperme na ontdooiing was dit duidelik dat sperme verkry van die Hoë Lyn ramme 'n
groter mate van akrosoom-oppervlak gehad het, in vergelyking met sperme van die Lae Lyn
ramme. Die byvoeging van seminale plasma by epididimale monsters het nie bygedra tot 'n
verbetering van spermbeweeglikheid nie. Bestaande literatuur dui aan dat diepbevriesing 'n
afname in die kopgrootte van sperme veroorsaak. In hierdie studie het die byvoeging van
seminale plasma ʼn verandering in kopgrootte voorkom, wat dui op ʼn potensiële voordeel om
seminale plasma in die bevriesingsprotokol van epididimale ramsperme in te sluit.
Die studie het twee beweeglikheid bepalingstegnieke vergelyk om te bepaal of die tydrowende
“opswem” tegniek (SUT) vervang kan word met 'n meer tyd-doeltreffende "spoel tegniek” (FT) in
die voorbevriesing verwerking protokolle van ram sperme. Vergelyking van die twee tegnieke
het aangedui dat die meeste van die kinematiese eienskappe van die FT gunstig met die
waardes soos verkry met die SUT, vergelyk het. Resultate het getoon dat die FT parameters
goed vergelyk met die beweeglikheid parameters van die SUT, dus kan dit aangeneem word
dat die FT ʼn meer tyd-doeltreffende tegniek is wat vergelykbare sperm beweeglikheidsinligting
oor skaap sperm monsters voor bevriesing sal verskaf.
In samevatting is verskille in terme van die dekvermoë en op morfometriese vlak, meer spesifiek
die eienskappe van verlenging (elongation) en elliptisiteit, tussen die twee lyne waargeneem. In
toekomstige studies moet die morfometriese eienskappe van skaapsperme verder bestudeer
word, asook die korrelasie daarvan met die bevrugtingsvermoë na ontdooiing bepaal om
sodoende die diepbevriesing protokolle van skaapsperme te optimaliseer.
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Economic value and genetic prediction of clinical mastitis in South African Holstein cattleMan'ombe, Edson 04 1900 (has links)
Thesis (MScAgric)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Mastitis is the most prevalent and costly production disease of dairy cattle; hence mastitis
incidence is a distinctly important trait in dairy cattle. The primary objective of the study
was to determine the economic value, and develop a model for genetic prediction of clinical
mastitis in South African Holstein cattle. These procedures are a prerequisite to including
this trait in the breeding objective. The cost of clinical mastitis per incident was calculated as
the sum of revenue loss due to discarded milk during the infection period and the
associated treatment costs. Economic value (ZAR/incident) was calculated as the change in
profit (increase in costs) resulting from a simulated marginal increase in mastitis incidence in
an average herd. Average economic losses due to clinical mastitis were estimated at
ZAR919.96/cow/year and the average incidence was 0.9cases/cow/year. The economic
value of clinical mastitis was ‐ZAR1079.51/incident. A model for predicting estimated
breeding values (EBVs) for clinical mastitis using somatic cell score (SCS), fore teat length
(FTL), udder depth (UD) and rear udder height (RUH) was developed, using genetic
(co)variances among these traits. Since EBVs for SCS, FTL, UD and RUH are routinely
estimated under the national genetic evaluation programme, EBVs for clinical mastitis can be predicted from the model developed in the current study. Thus, the results of the study
provide the basis for including clinical mastitis in the breeding objective for South African
Holstein cattle. / AFRIKAANSE OPSOMMING: Mastitis is die mees algemeenste en duursteproduksie siekte wat voorkom by melkbeeste,
daarom is die voorkoms van mastitis 'n belangrike eienskap in melkbeeste. Die primêre doel
van die studie was om die ekonomiese waarde te bepaal, asook die ontwikkeling van 'n
model vir genetiese voorspelling van kliniese mastitis in Suid‐Afrikaanse Holstein beeste.
Hierdie prosedures is 'n voorvereiste vir insluiting van hierdie eienskap as ‘n teeldoelwit in
seleksie programme. Die koste van kliniese mastitis per voorval is bereken as die som van
die inkomste verlies weens melk weggegooi tydens die infeksie periode en die
gepaardgaande koste vir die behandeling. Ekonomiese waarde (ZAR / voorval) is bereken as
die verandering in wins (toename in koste) wat voortspruit uit 'n gesimuleerde marginale
toename in mastitis voorkoms in 'n gemiddelde kudde. Gemiddelde ekonomiese verliese as
gevolg van kliniese mastitis was beraam op ZAR919.96/koei/jaar en die gemiddelde
voorkoms was 0.9gevalle/koei/jaar. Die ekonomiese waarde van kliniese mastitis was ‐
ZAR1079.51/geval. 'n Model vir die voorspelling van beraamde teelwaardes (EBV’s) vir
kliniese mastitis is ontwikkel deur gebruik te maak van die ko‐variansies tussen die
onderskeie eienskappe: somatiese sel telling (SST), voorspeen lengte (VSL), uier diepte (UD)
en agter uier hoogte (AUH). Aangesien teelwaardes vir SST, VSL, UD en AUH gereeld beraam
word onder die Nasionale genetiese evaluasie program, kan teelwaardes vir kliniese mastitis
voorspel word vanuit die model wat ontwikkel is in die huidige studie. Dus verskaf die
resultate van hierdie studie ‘n basis vir die insluiting van kliniese mastitis as ‘n teeldoelwit in
seleksie programme van die Suid‐Afrikaanse Holstein beeste.
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Comparison of production parameters, gut histology, organ weights, and portion yields of broilers supplemented with Ateli plusTeuchert, Nicole 04 1900 (has links)
Thesis (MScAgric)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Antibiotic growth promoters (AGP’s) have been used in feed of production animals to improve
their growth performance and disease resistance. However, there has been an increase in the
presence of antibiotic residue in animal products, as well as an increase in untreatable illnesses
due to antibiotic resistant bacteria. This led to the European Union banning the use of antibiotic
growth promoters, in production animals, in 2006. An alternative to AGP’s is therefore needed in
animal feed in order to maintain performance. Plant extracts and essential oils have gained
much attention, due to their natural antimicrobial, antibacterial, anticoccidial and antioxidant
properties. This study tested the efficiency of Ateli plus®, an oregano plant extract based
product, as a replacement to AGP’s on production parameters, carcass characteristics and
organ and gut health of broilers.
This study consisted of five treatments fed to broilers from hatch till 33 days of age, fed in three
phases; starter, grower and finisher. The treatment diets consisted of a negative control (no
AGP), positive control (AGP), Ateli plus® at 1kg/ton (Ateli plus® min), Ateli plus® at 2kg/ton for
week one followed by 1kg/ton for the remainder of the period (Ateli plus® max), and AGP plus
Ateli plus® max (AGP plus Ateli plus® max). Results from this study show that there was no difference in performance parameters between
treatments. The performance parameters tested included liveability, average daily gain (ADG),
average weekly feed intake, average cumulative feed intake, average weekly live weight,
average cumulative weight gains, feed conversion ratio (FCR), cumulative FCR and the
European production efficiency factor (EPEF). Broiler breast and thigh muscle pH and colour
(L*, a* and b*) reading values were measured, showing a trend for improved L* colour reading
value and ultimate pH, in broilers supplemented with Ateli plus®. This leads to an increase in
water binding capacity and tenderness, therefore resulting in an improvement in meat quality.
No differences were shown for dressing percentage and portion percentages relative to carcass
weight. No significant differences were seen for tibia bone Ca and P content, or tibia bone fat,
moisture or ash percentages. However a significant decrease in tibia bone strength was found
in all broilers supplemented with Ateli plus® diets and the negative control diet, compared to
AGP supplemented broilers. Gut morphology showed no consistent effect of treatment on villi
height or crypt depth of the duodenum, jejunum and ileum. No significant differences between
treatments were found for organ pH or organ weights, except the gizzard, which was heavier for
Ateli plus® max supplemented broilers.
Ateli plus® shows promise on improving meat quality characteristics of broilers, however the
significant decrease in tibia bone strength in Ateli plus® supplemented broilers is a major
concern and needs to be researched further. Ateli plus® acts as a good AGP replacement, as
broiler performance for the Ateli plus® supplemented broilers was maintained, and not decreased, when compared to the AGP supplemented broilers. However, the broilers fed the
negative control diet had performance parameters statistically equal to both the Ateli plus® and
AGP supplemented broilers, as well as no significant differences between organ weights were
found. It can therefore be said that the broilers were raised under good management, and their
optimal environmental conditions. Therefore conclusive effectiveness of Ateli plus® as a
replacement for AGP on broiler performance cannot be reported from this study. / AFRIKAANSE OPSOMMING: Antibiotiese groeistimulante (AGP’s) word gereeld as voerbymiddels vir diere gebruik om groei
en siekte weerstandbiedenheid te verbeter. Die verbod op die gebruik van antibiotika as 'n
groeipromotor in die Europese Unie (sedert 2006) kan toegeskryf word aan die toename in
onbehandelbare siektes as gevolg van weerstandbiedende bakterieë, asook die
teenwoordigheid van residue in die dierlike produkte. Alternatiewe vir AGP’s in dierevoeding
word dus benodig om produksie te handhaaf. Plant ekstrakte en essensiële olies het baie
aandag gekry as gevolg van hul natuurlike antimikrobiese, antibakteriële, antikoksidiese en
antioksidatiewe eienskappe.
'n Studie is gedoen om die doeltreffendheid van Ateli plus® ('n origanum plant ekstrak
gebaseerde produk) op groei produksie parameters, karkaseienskappe, orgaan- en
dermgesondheid te bepaal wanneer Ateli plus® as 'n AGP plaasvervanger in die dieëte van
braaikuikens gebruik word. Gedurende die proef was vyf verskillende diëte/behandelings vir 33
dae vir braaikuikens gevoer. Die behandelings het bestaan uit 'n negatiewe kontrole (geen
AGP), positiewe kontrole (AGP), Ateli plus® teen 1kg/ton (Ateli plus min), Ateli plus® teen
2kg/ton vir die eerste week gevolg deur 1kg/ton vir die res van die tydperk (Ateli plus® max), en
AGP plus Ateli plus® max (AGP plus Ateli plus® max). Resultate van hierdie studie toon dat behandelings nie 'n effek op produksie parameters gehad
het nie. Die groei produksie parameters wat getoets is sluit in oorlewing, gemiddelde daaglikse
toename (GDT), die gemiddelde weeklikse voer-inname, gemiddelde kumulatiewe voerinname,
gemiddelde weeklikse lewendige massa, gemiddelde kumulatiewe gewig toename,
voeromsetverhouding (VOV) en die Europese produksie doeltreffendheid faktor (EPEF). Die
pH en kleur (L*,a* en b* waardes) van die dy- en borsspier is gemeet. Ateli plus® aanvulling in
braaikuiken diëte het 'n tendens getoon vir verbeterde L * en finale pH waardes in die spiere,
wat lei tot 'n toename in waterhouvermoë en sagtheid en dus verbeterde vleiskwaliteit. Geen
verskille tussen behandelings is gevind vir uitslagpersentasie en die massa van porsies
(uitgedruk as persentasie relatief tot karkasgewig) nie. Behandelings het nie 'n effek op die vet,
vog, as persentasies of Ca- en P-inhoud van die tibia gehad nie.
In vergelyking met AGP aangevulde braaikuikens, is 'n beduidende afname in die tibia
breeksterkte van kuikens in die negatiwe kontrole groep en kuikens wat met Ateli plus®
aangevul is, gevind. Spysverteringskanaal morfologie het getoon dat behandeling geen
konsekwente effek op villi hoogte of krip diepte van die duodenum, jejunum en ileum gehad het
nie. Slegs die krop massas van kuikens wat met Ateli plus® max aangevul is, was swaarder in
vergelyking met hoenders in die ander behandelings; verder is geen beduidende verskille
tussen behandelings gevind vir orgaan pH of orgaan gewigte nie.
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The evaluation of the effect of Acid Buf™ on stomach ulcer occurrence, growth performance and histological parameters of grower - finisher pigsSteenkamp, Jan Adriaan 04 1900 (has links)
Thesis (MScAgric)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The objective of this study was to determine the effect of the inclusion of Acid Buf™ at 4g.k–1 g to a maize-soya bean diet in both pelleted and meal form, on the occurrence of stomach
ulcers, performance parameters, carcass characteristics and histological parameters of the
small intestine of growing finisher pigs. The trail was done on 320 growing finisher pigs fed
for 8 weeks. The four treatments (Tr) were as follows: Tr1 – pelleted, Tr2 – meal, Tr3-
pelleted with Acid Buf™ at 4g.kg-1, Tr4 –meal with Acid Buf™ at 4g.kg-1.
No significant differences (P>0.05) were observed for cumulative feed intake between the
different treatments. The feed conversion ratio (FCR) showed significant differences with the
pigs on the meal diet faring significantly (P<0.05) worse than those the pelleted diet
containing Acid Buf™. The average daily gain (ADG) on Tr3 was significantly better
(P<0.05) than those on the meal diets. Overall the performance parameters showed a
positive response to the inclusion of Acid Buf™.
With regards to changes in the intestinal pH, significant differences (P<0.05) were observed
between the different treatments for pH in the stomach, duodenum and colon. The pH in the
stomach was closest to optimal with Tr3m and Tr4. The pH in the duodenum was highest
and closest to optimum with Tr4.
Scoring of stomachs revealed that the highest percentage of normal stomachs was found in
pigs on Tr4, with 64.1% of the stomachs being normal,57.1% was the second highest
percentage of normal stomachs and was found with Tr3, pelleted with AB. Carcass scoring
showed no significant differences (P>0.05) between the different treatments. The mean villi height to crypt depth ratio (VH: CD) in the jejunum showed a significant
difference (P<0.05) between Tr1 and Tr3. The pigs on the pelleted diet had VH: CD of 0.89
while those on the pelleted diet with AB a VH: CD of 1.28. The average villi height
measured in both the duodenum and the jejunum was higher in both of the pelleted diets
compared to the meal diet and the meal with AB diet. The results of the different
experiments conducted to evaluate the effect of AB all showed improved results with the
inclusion of AB to the diet. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die effek van die insluiting van Acid Buf™(AB) teen 4g.kg-1 in 'n mielie-sojaboondieët in beide verpilde- en meelvorm, op die voorkoms van
maagsere, groei parameters, karkaseienskappe en histologiese parameters van die
dunderm in groeivarke te bepaal. Die studie is vir agt weke op 320 groei varke uitgevoeroor.
Die vier behandelings (Tr) was soosvolg: Tr1 - verpil, Tr2 - meel, tr3- verpil met Acid Buf™
teen 0,4% ingesluit, Tr4 – meel metAcid Buf™ teen 0,4% ingesluit.
Daar was geen beduidende verskille (P> 0.05) in die kumulatiewe voerinname tussen die
verskillende behandelings waargeneem nie. Voeromsetverhouding (VOV) op die meel diet
(Tr4) het beduidend swakker gevaar (P<0.05) as die varke op Tr3. Die gemiddelde
daaglikse toename (GDT) van die varke op Tr3 was aansienlik beter (P<0.05) as die van die
varke op Tr2.
Met betrekking tot die pH van die spysverteringskanaal was daar beduidende verskille
(P>0.05) opgemerk tussen die verskillende behandelings vir pH in die maag, duodenum en
kolon. Die pH in die maag was die laagste en naaste aanoptimaal vir die AB dïete . Die pH
in die duodenum was die hoogste en naaste aan optimaal met Tr4.
Gradering van die mae toon die hoogste persentasie van normale, met 64.1 % van die mae
met Tr4 normaal. Die tweede hoogste persentasie was 57.1 % normale mae en was gevind
met Tr3, verpil met AB. Karkasgradering het geen beduidende verskille (P>0.05) tussen die
verskillende behandlinge getoon nie. Die gemiddelde villi hoogte kryptdiepte verhouding (VH: KD) in die jejenum het beduidende
verskille (P<0.05) getoon tussen Tr1 en Tr3. Die verpilde diet (Tr1) het n (VH: KD) van 0.89
getoon en Tr3, die varke op die verpilde diët met AB 1.28. Die gemiddeldie villi hoogte
gemeet in beide die duodenum en jejenum was hoër in die beide die verpilde diëte as in die
meel diëte. Die resultate van die verskillende eksperimente uitgevoerom die effek van AB
teevalueer, toon verbetering met die insluiting van AB in die diët.
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Management and reproduction of the African savanna buffalo (Syncerus caffer caffer)Hildebrandt, Walter Ralph 04 1900 (has links)
Thesis (MScAgric)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The aim of this study was to evaluate the current managerial practices as used by African
Savanna buffalo (Syncerus caffer caffer) farmers. Consequently, the best management
practices would be combined to formulate a basic management plan to farm captive buffalo.
The distribution of buffalo throughout South Africa was also investigated and each province
was considered separately for different types of buffalo (Kruger also known as project; Addo
and other) and different disease statuses (Foot and Mouth; TB; Corridor disease and
disease-free or clean). The basic infrastructure of all farms studied was noted and evaluated
to attain the most effective structures and layouts needed for basic captive buffalo farming.
The reproductive capabilities of buffalo were assessed on different farms. These farms were
divided into winter and summer rainfall areas to ascertain whether season or rainfall would
have an effect on calving season. Additionally the reproduction data was analysed to set a
benchmark for the reproductive performance of buffalo in herds as well as individually. This
assisted in selection in captive breeding of buffalo.
Buffalo are currently distributed throughout South Africa and occur in all nine
provinces, with the highest quantity found in Limpopo with 1300 registered buffalo farms.
Provinces that contain only disease-free buffalo include Western Cape, Eastern Cape,
Freestate, North-West and Gauteng. Corridor infected buffalo are found in the Northern
Cape, Mpumalanga and KwaZulu Natal. Foot and Mouth disease is found in Limpopo and
Mpumalanga and TB infected buffalo are found in Mpumalanga and KwaZulu Natal.
Factors to consider when managing captive buffalo herds are the herd dynamics and
composition, feeding and nutrition and lastly parasite control. Management should be
approached adaptively as different areas present different challenges.
Infrastructure is divided into the farm and biomes thereof, feeding and parasite
treatment. As with herd management these should be approached adaptively as the
composition of each farm differs.
Reproductive maturity of buffalo is reached between the ages of two and six years.
Average intercalving period of captive buffalo was to be 443 days with optimal intercalving
being below 400 days. Seasonal calving differences between summer and winter rainfall
areas were found with calving peaks differing by two months between these areas. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die bestuurstegnieke wat tans deur Afrika Savanna
buffel (Syncerus caffer caffer) boere gebruik word te evalueer. Gevolglik sal die beste
bestuurs praktyke gekombineer word om ‘n basiese bestuursplan the formuleer om
omheinde buffels te boer. Die verspreiding van buffels in Suid-Afrika is ook ondersoek en
elke provinsie is afsonderlik oorweeg vir die verskillende tipes buffels (Kruger ook bekend as
projek; Addo en ander) en verskillende siektestatusse (Bek-en-Klou seer; TB; Corridor siekte
en siekte-vrye of skoon). Die basiese infrastruktuur van al die plase in die studie is genoteer
en geivalueer op die mees effektiewe strukture en uitlegte vas te stel wat benodig word vir
die boer van omheinde buffels. Die reproduktiewe vaardighede van buffels is geassesseer
op verskillende plase wat verdeel is in winter en somer reënval streke om vas te stel of
seisoen of reënval ‘n invloed het op kalf seisoen. Die reproduksie data is ook geanaliseer om
‘n riglyn te stel vir die reprodutiewe prestasie van buffels in ‘n kudde asook individueel. Dit
sal help met die seleksie van teel diere.
Buffels is tans wyd versprei oor Suid-Afrika and kom in al nege provinsies voor met die
hoogste hoeveelheid in Limpopo (1300 geregistreerde buffelplase). Die provinsies wat slegs
siekte-vrye buffels bevat is Wes-Kaap; Oos-Kaap; Vrystaat; Noord-Wes en Gauteng.
Corridor-besmette buffels kom voor in Noord-Kaap; Mpumalanga en KwaZulu Natal. Bek-en-
Klou seer kom voor in Limpopo en Mpumalanga en TB kom voor in Mpumalanga en Kwa-
Zulu Natal.
Faktore wat oorweeg moet word met die bestuur van omheinde buffeltroppe is kudde
dinamika en samestelling, voeding en laastens parasiet beheer. Buffelbestuur moet
aanpasbaar wees aangesien verskillende areas verskillende uitdagings bied.
Infrastruktuur kan opgedeel word in die plaas en sy biome, voeding en parasiet
toediening. Soos met kudde bestuur moet infrastruktuur ook aanpasbaar wees, aangesien
die samestelling van elke plaas verskil.
Reproduktiewe volwassenheid van buffels word bereik tussen die ouderdomme van
twee en ses jaar. Gemiddelde interkalf periode vir omheinde buffels was 443 dae met
optimale interkalwing van minder as 400 dae. Seisoenale kalwingsverskille tussen somer en
winter reënvalstreke is opgemerk met kalf pieke wat verskil met twee maande tussen die
streke.
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Reducing height and lodging in canola (Brassica napus L.) using plant growth regulatorsEksteen, Lambertus Lochner 12 1900 (has links)
Thesis (MScAgric)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: In South Africa, canola (Brassica napus L.) is produced under short day conditions during winter months. These conditions, together with high fertiliser application levels required to maximize grain yields, often result in tall growing bulky crops which are prone to lodging. This will especially be true if canola production is expanded to irrigated areas. Plant growth regulators (PGRs) have successfully been used to reduce canola plant height and lodging under experimental conditions in Australia and are worldwide commercially used to reduce plant height and lodging in winter cereals such as wheat and barley. The primary objective of this study was to determine the effect of anti-lodging PGRs on the agronomic and quality characteristics of commercial canola cultivars under South African conditions.
This study was conducted under field conditions at three research farms, as well as controlled glasshouse conditions at Welgevallen Research Farm, situated in the Western Cape Province of South Africa. Foliar treatments consisted of a control (untreated) and four PGRs; CeCeCe® 750 (chlormequat chloride), Moddus® 250 EC (trinexapac-ethyl), Primo MAXX® (trinexapac-ethyl), and Kelpak®, applied either individually or in combination with wetting agent at budding stage (growth stage 3.1) of canola. Whilst glasshouse trials were conducted with spring canola cultivars “Hyola 555TT” and “43C80”, field trials were done with Hyola 555TT only. Monitoring and measuring various plant parameters during different growth stages of canola, the morphological and physiological impact of PGR-treatments on growth and development were determined. Though Primo MAXX® tends to reduce plant height in all trials; reductions were only significant during one of the glasshouse trials. Fortunately, compared to the control, none of the PGRs significantly reduced the leaf area, number of flowers or number of pods plant-1 during this study, while Primo MAXX® and Moddus® 250 EC tend to increase the grain yield under field conditions. This study indicates that PGRs can possibly be used to improve lodging resistance and yield of canola. Identifying the most effective PGRs on specific cultivars, the results of the study will contribute to the knowledge of using PGRs in canola to reduce lodging and improve grain yields in South Africa. / AFRIKAANSE OPSOMMING: In Suid-Afrika word canola (Brassica napus L) gedurende die wintermaande onder kort-dagtoestande verbou. Hierdie verbouingstoestande, tesame met verhoogde toediening van bemesting vir maksimum opbrengs, lei dikwels tot welige, hooggroeiende plantegroei, wat „n geneigdheid toon om om te val (lodge). Hierdie probleem vererger indien canola onder besproeiingstoestande gekweek sou word. Plantgroeireguleerders (PGRs) is reeds met sukses onder eksperimentele toestande in Australië gebruik om die planthoogte en dus omval (lodging) van canola te beperk. Plantgroeireguleerders word reeds kommersieel gebruik om planthoogte en omval van wintergraangewasse, soos koring en gars te verminder. Die hoofdoel van hierdie studie was om die effek van omval-teenwerkende PGRs op die agronomiese en kwaliteitseienskappe van kommersiële canola-kultivars onder Suid-Afrikaanse groeitoestande te bepaal.
Hierdie studie is uitgevoer d.m.v. veldproewe op drie navorsingsplase, sowel as gekontrolleerde glashuisproewe te Welgevallen Navorsingsplaas, geleë in die Wes-Kaapprovinsie van Suid-Afrika. Blaartoedienings het bestaan uit „n kontrole (onbehandeld) en vier PGRs: CeCeCe® 750 (chlormequat chloride), Moddus® 250 EC (trinexapac-ethyl), Primo MAXX® (trinexapac-ethyl) en Kelpak®, wat afsonderlik of in kombinasie met benattingsmiddels toegedien is tydens die blomknopverskyningstadium (groeistadium 3.1) van canola. Die glashuisproewe is uitgevoer met lente-canolakultivars, nl. “Hyola 555TT” en “43C80”, terwyl veldproewe slegs uitgevoer is met Hyola 555TT. Verskeie plantparameters is gemonitor en gemeet gedurende die verskillende groeistadia van canola, waartydens en die morfologiese en fisiologiese impak van PGR-toedienings op die groei- en ontwikkeling van canola bepaal is. Alhoewel Primo MAXX® neig om die planthoogte in al die proewe te verkort, het dit planthoogte slegs beduidend verkort in een van die glashuisproewe. Geen van die PGRs het in vergelyking met die kontrole, die blaar-oppervlakte, aantal blomme of aantal peule plant-1 beduidend verminder gedurende die studie. Primo MAXX® en Moddus® 250 EC het inteendeel daartoe geneig om die saadopbrengs onder veldtoestande te verhoog. Hierdie studie toon dus dat PGRs moontlik gebruik kan word om omval te verminder en die opbrengs van canola te verhoog. Deur die mees doeltreffendste PGRs op spesifieke kultivars te identifiseer, kan die resultate van hierdie studie bydra tot die kennis van die gebruik van PGRs op canola, om omval te voorkom en saadopbrengs in Suid-Afrika te verhoog.
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