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Factors affecting the utilisation of dietary energyKese, Adu Gyamfi January 1977 (has links)
Seven different but integrated experiments were conducted to study the factors affecting the utilisation of dietary energy. The first two experiments involved feeding broiler chickens diets containing either corn oil or corn starch as the supplementary source of energy at two protein levels. Herring meal was used in all diets because of the high biological value of its protein. All diets were calculated to be isocaloric and to contain the same balance of amino acids; minerals and vitamins were added to meet the requirements for these nutrients.
Live weight gain and the efficiency of food utilisation within calorie:protein regime were not improved when fat was substituted for starch in isocaloric diets. The superiority of the low-fat high-protein diet in promoting the highest metabolisability of energy, questions the validity of the claim that added dietary fat has an "extra-caloric" effect. Birds fed the high-fat low-protein diet which had a lower calorie:protein ratio, deposited more abdominal adipose tissue, indicating that in evaluating growth performance, the balance between energy and protein is of greater significance than the source of supplementary energy.
Formulation of isocaloric diets has necessitated the inclusion of the so-called nutritionally-inert ingredients such as cellulose. Since the diets used to test the main hypothesis of "extra-caloric effects" attributable to dietary fat incorporated cellulose, the effect of the
latter on the physiological parameters under study, was tested. At high levels of inclusion cellulose depressed body weight gain. Adverse effects of added dietary cellulose on food conversion efficiency and energy metabolisability were also evident. Another effect of .added dietary cellulose which is particularly interesting is that it decreased abdominal adipose tissue.
Results of the above studies have shown significant differences among the different treatment groups in body weight gain, efficiency of food utilisation and metabolisability of energy within the first three weeks posthatching. The possibility that the residual yolk may influence the metabolic parameters in question was considered and tested. Absence of the yolk sac, excised surgically, did not influence the performance of birds on the basis of growth and energy utilisation as measured by body weight gain and metabolisable energy values, respectively. The residual yolk did not influence food conversion efficiency in the first and third weeks of the experimental period. However, depression of food conversion efficiency resulting from the removal of residual yolk was found to occur in the second week. It was noted that birds without residual yolk retained a greater amount of nitrogen compared to birds with residual yolk in the first week posthatching.
The residual yolk does not contribute significantly towards the nourishment of the chick in the first week posthatching as evidenced by the fact that abstinence from food resulted in the death of both the groups retaining yolk sacs and those without yolk sacs at approximately the same time.
The presence of a large bacterial population in the avian caeca
and extrapolation of the features associated with bacteria-host symbiosis in ruminants and other animals to the domestic chicken have led to speculation that the avian caeca perform some cellulolytic and proteolytic functions. The relevance of the concept of caeca-mediated nutrient utilisation to the topic under study prompted an experiment using intact and caecectomized chickens to investigate the effect of the excision of the caeca on the utilisation of dietary energy and protein. Caecectomized and intact control New Hampshire cockerels were fed diets used in the previous studies. Metabolisable energy values and uric acid excretion were used as the criteria for measuring dietary energy and protein utilisation. Caecectomy did not affect the metabolisability of the diets. Metabolisability of the diet incorporating corn starch was more variable and slightly lower with the caecectomized birds. Uric acid excretion was similar for the caecectomized and the intact birds.
Macroscopic and histological examination of sections of the caeca revealed that regeneration of the caeca had occurred in four caecectomized birds that survived until autopsy 85 weeks later. Although the onset of the regeneration of the caeca was not observed, it would appear that the degree (or the absence) of regeneration of the caeca in caecectomized birds may be responsible for the discrepancies in the findings reported with such birds. / Land and Food Systems, Faculty of / Graduate
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Determining variables linked to the phenotypic expression of fedd efficiency using residual feed intake as a measure of efficiency /Golden, Joseph W. January 2004 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 82-89). Also available on the Internet.
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Determining variables linked to the phenotypic expression of fedd efficiency using residual feed intake as a measure of efficiencyGolden, Joseph W. January 2004 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 82-89). Also available on the Internet.
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A comparison of the effects of carbohydrate and fat as energy sources in trout and chick diets on tissue glycogen concentration and on the rate of glycogen depletion from the tissues during a subsequent period of fastHickling, David Robert January 1981 (has links)
Rainbow trout, about one-year-old, were fed diets containing either glucose (C) or herring oil (F) as the non-protein energy source for a period of two weeks. As well, they were fed each diet at satiation (C-2, F-2) and at levels half that (C-l, F-l). The trout were subsequently fasted and sampled for tissue glycogen, protein, dry matter and glucose-6-phosphatase activity at full feeding and at 2, 4, 8, 10, 13 and 16 days of fasting.
The livers of the C-fed fish had 12% wet weight glycogen and the livers of the F-fed fish had 3% wet weight glycogen at full feeding. Upon fasting, glycogen concentrations in the F-fed fish livers fell to basal levels of 1% by 2 days while glycogen concentrations in the C-fed fish livers fell to basal levels only after 10 days.
The protein concentration in the trout livers was inversely related to the glycogen concentration. The amount of liver protein in the trout carcass, however, was directly related to dietary carbohydrate levels.
Trout liver glucose-6-phosphatase activity increased as fasting progressed but there were no treatment differences in enzyme activity.
The muscle of the C-2 fed trout contained .4% glycogen at full feeding. The muscle of the other dietary treatments contained .1-.15% glycogen. It appears that trout muscle stored dietary carbohydrate that was not taken up by the liver or that was not oxidized. Upon fasting there was a depletion in muscle glycogen to basal levels of .05% after
4 days. Thereafter there occurred a rebound in muscle glycogen to levels at or greater than full-fed levels followed by a decline back to basal values. The rebound was greater and peaked earlier (8 days) in the C-fed trout than in the F-fed trout (10 days).
Broiler (BR) and White Leghorn (WL) pullet chicks were fed diets, where 25% of the energy was supplied as corn starch (C) or corn oil (F), for a three-week period. The chicks were then fasted and sampled for tissue glycogen, protein and dry matter at full feeding and at 8, 16, 24, 32, 44, 56, 80, 104 and 128 hours of fasting.
The BR livers contained more glycogen (3%) than the WL livers (2%) and the C-fed chicks had greater liver glycogen concentrations (3%) than the F-fed chicks (2%) at full feeding. Upon fasting, liver glycogen fell to basal levels of .03% after 8 hours. Thereafter there was a rebound increase in liver glycogen levels to a peak of 1% and a subsequent tapering off. The rebound occurred earlier in the C-fed chicks than in the F-fed chicks. The peak was attained earlier in the WL (32-44 hours) than in the BR (50 hours).
The amount of liver protein in the C-fed chicks was higher than that in the F-fed chicks over the entire fasting period.
Chick muscle glycogen concentrations were initially higher in the C-fed than in the F-fed chicks and higher in BR (1.2%) than in WL (.8%). Upon fasting, BR muscle glycogen concentrations were maintained while those of WL fell to .3%. There were erratic fluctuations in muscle glycogen levels. / Land and Food Systems, Faculty of / Graduate
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Some effects of silica on assimilation efficiency and diet discrimination in prairie voles (Microtus ochrogaster)Trott, Dale Richard January 2011 (has links)
Typescript. / Digitized by Kansas Correctional Industries
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Energetic efficiency of maintenance and production by broilersCairo, William Henry January 1980 (has links)
No description available.
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A comparative analysis of nutrient utilisation and meat quality parameters of boer goats and South African mutton merinosSheridan, Rouxlene 12 1900 (has links)
Thesis (MScAgric)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: One of the reasons why meat supply does not meet human demand is that man has
concentrated on utilising relatively few animal species as a source of meat. Development of
unconventional livestock, such as goats, is advocated as a means of increasing global meat
production and consumption. Although South Africa possesses large numbers of domestic
ruminants, meat consumption has been limited mainly to sheep and cattle. Goats are used to
a lesser extent. This is partly attributed to a general belief that goat meat is inferior to mutton
and beef.
Numerous contradictions regarding comparative goat and sheep growth, carcass
characteristics and meat composition exist in literature. Concepts involved with most of the
contradictions includes average daHy gain (ADG), dressing percentage, carcass weight
distribution and organoleptic characteristics, especially tenderness, juiciness and flavour,
particularly as pertaining to animals reared/grown under intensive/feedlot conditions.
Therefore this project was undertaken to obtain more information on the growth, carcass and
organoleptic characteristics, as well as meat chemical compositions of Boer goat (BG) kids in
comparison with South African Mutton merino (MM) lambs, reared under feedlot conditions.
Thirty-two BG kids and 32 MM lambs were used for this investigation. All the animals were
castrated and weaned before entering the feedlot. Two pelleted diets (fed to 16
animals/species) with either a low (LE; 8.9 MJ/kg OM) or a high (HE, 10.9 MJ/kg OM)
metabolisabie energy level were fed individually, ad lib for either 28 or 56 days. Feed and
water intake, ADG and feed conversion efficiencies (FCE) were monitored. During the last week of the feeding trial, 12 BG kids and 12 MM lambs were used to evaluate the digestibility
of the two diets.
After either 28 or 56 days, the animals were slaughtered and the carcasses dissected into
South African commercial cuts. The m. semimembranosus and 8-9-10-rib cut of each carcass
was dissected for determination of chemical composition, drip loss, cooking loss, shear force
values and colour measurement. The m. gracilis was dissected from the hind leg of the
carcass and used for sensory evaluation.
MM's had significantly higher AOG's than BG's (e.g. MMHE56: 0.281; BGHE56: 0.162
kg/day). Within a diet there was no difference (P>0.05) in FCE between BG's and MM's and
only the MM's FCE differed between the LE and HE diet (e.g. BGLE28: 7.65; BGHE28: 6.37;
MMLE28: 8.73; MMHE28: 5.56 kg feed/kg weight gain). BGLE digested dry matter (OM),
crude protein (CP) and energy more efficiently and had a higher energy retention than MMLE.
The two diets had the same ME-value for the goats, which confirms that goats perform equally
well on a lower quality feed as their contemporaries on a higher quality feed. Neither species,
nor diet affected nitrogen retention. The BG had a 49 % lower (P<0.01) water intake per kg
weight gain than the MM on both the high and low energy diets. Both species had a lower
(P<0.01) water intake on the high than on the low energy diet. Furthermore, the BG had a
daily water intake of only 171 ml/kgo.75 compared to the 302 ml/kgo.75 of the MM.
The weight of the liver, empty stomach, head and feet (as a percentage of empty body weight)
were higher in goats than in sheep. The MM's had significantly heavier skins, probably due to
wool growth. Both kidney fat and gastro-intestinal tract (GIT) fat increased with age. The
animals slaughtered after 56 days in the feedlot had significantly longer and deeper carcasses
than their contemporaries slaughtered after 28 days. Within a diet and slaughter age, the MM
had significantly broader and deeper carcasses than the BG's. BG's had significantly less
weight per unit carcass length, and thus more slender carcasses than MM's. Diet had no
significant influence on the carcass weight distribution of the goats. However, MM's had
heavier carcasses (LE: 19.87 vs. 15.28 kg; HE: 24.01 vs. 17.05 kg) and proportionally heavier
ribs and buttocks than BG's.
Neither diet nor slaughter age influenced the proximate analysis of the m. semimembranosus,
but MM's had significantly lower moisture values than BG's. In the 8-9-10-rib cuts BG's had
significantly more moisture and protein and lower fat and energy values than MM's. OM, fat
and energy values increased with an increase in slaughter age in both species. BG's had
significantly higher concentrations of 11 of the 18 measured essential amino acids in their 8-9-
10-rib cuts than the MM's. Gaat carcasses had higher Ca, K, Mg, Na and P-Ievels than sheep
carcasses, regardless of the diet fed. There was a tendency for goat's m. semimembranosus
to have a lower Fe-content than that of sheep. BG carcasses had a lower carcass cholesterol content than that of lamb (66.77 vs. 99.28
mg/100g, respectively). Palmitic (C16:0), stearic (C18:0) and oleic (C18:1 n9) acid comprised
the greatest proportions of fatty acids in both the m. semimembranosus and 8-9-10-rib cut for
both species. On a LE-diet there was no significant difference between the saturated fatty
acid (SFA) to unsaturated fatty acid (UFA) ratio of goat meat and lamb. However, on the HEdiet,
lamb had a significantly higher SFA:UFA ratio than chevon (m. semimembranosus: 0.842
vs. 0.689; 8-9-10-rib cut: 1.407 vs. 0.892). Organoleptically, a difference was noted between
chevon and lamb. Each has a specific species flavour, which was not influenced by energy
level of the diet. BG meat was perceived to be stringier than that of the MM, but there was no
significant difference in Warner-Bratzler shear force values. Tenderness declined with age in
both species and there was also a tendency for goat meat to be less juicy than lamb. Chevon
had a more pronounced aftertaste than lamb. No objective differences could be distinguished
between the colour of the cooked chevon and lamb. There was a tendency for fresh lamb to
have a higher a*-value (redness) than chevon. Although diet did not influence drip loss, drip
loss increased with an increase in slaughter age. Only after 56 days did the MM's m.
semimembranosus have a significantly higher drip loss than the BG's (LE: 4.84 vs. 3.43%;
HE: 4.72 vs. 3.32%). In the m. semimembranosus of both species, cooking loss increased
with an increase in slaughter age.
Since diet did not influence the growth, carcass weight distribution, water holding capacity,
colour, shear force values or organoleptic qualities of chevon, BG's may be finished on a diet
with a lower ME-value than that usually formulated for sheep, without a reduction in
performance. This may render a direct economic advantage for BG feedlot finishing. Meat
from young feedlot goats is not inferior to that of lamb and it has a higher protein percentage
and lower fat percentage. Therefore, it can be considered as a healthy food commodity,
especially among low-income groups or people wishing to consume a low calorie diet. / AFRIKAANSE OPSOMMING:
'n Vergelykende analise van nutriëntverbruik en vleiskwaliteisparameters van
Boerbokke en Suid-Afrikaanse Vleismerino's:
Een van die hoofredes waarom die vraag na vleis die aanbod oorskrei, is die feit dat die mens
tot op hede net op 'n paar dierspesies as bron van vleis gekonsentreer het. Benutting van niekonvensionele
spesies, soos bokke, kan aanbeveel word ten einde die globale vleisproduksie
en -verbruik te verhoog. Ten spyte van die feit dat Suid-Afrika oor baie gedomestikeerde
herkouerspesies beskik, is vleisverbruik in die verlede tot hoofsaaklik skape en beeste beperk.
Bokke is tot 'n mindere mate gebruik. Dit kan gedeeltelik toegeskryf word aan die algemene
siening dat bokvleis ondergeskik aan skaap- en beesvleis is.
Verskeie teenstrydighede ten opsigte van vergelykings tussen bokke en skape se groei,
karkaseienskappe en vleissamestelling bestaan in die literatuur. Teenstrydige resultate ten
bpsigte van gemiddelde daaglikse toename (GOT), uitslagpersentasie, karkasgewigverspreiding
en organoleptiese eienskappe (veral taaiheid, sappigheid en geur) van diere
afgerond onder intensiewe/voerkraal-toestande, kom veral voor. Hierdie projek is vervolgens
uitgevoer ten einde meer inligting ten opsigte van die groei, karkas- en organoleptiese
eienskappe, sowel as die chemiese samestelling van die vleis van Boerbok (BB) lammers in
vergelyking met Suid-Afrikaanse Vleismerino (VM) lammers, onder voerkraal-toestande
grootgemaak, te verkry.
Twee-en-dertig BB lammers en 32 VM lammers is vir hierdie studie gebruik. AI die diere is
gekastreer en gespeen voor hulle in die voerkraal geplaas is. Twee verpilde diëte (gevoer
aan 16 diere/spesie) met óf 'n lae (LE, 8.9 MJ/kg DM) óf 'n hoë (HE, 10.9 MJ/kg DM)
metaboliseerbare energievlak is individueel, ad lib, vir óf 28 óf 56 dae aan die diere gevoer.
Voer- en waterinname, GOT en voeromsettingsdoeltreffendheid (VOD) is gemonitor. Gedurende die laaste week van die voedingsproef is 12 BB'e en 12 VM's gebruik ten einde
die verteerbaarheid van die twee diëte te bepaal.
Na 28 of 56 dae is die diere geslag en die karkasse in Suid-Afrikaanse kommersiële snitte
verdeel. Die m. semimembranosus en 8-9-10-rib snit van elke karkas is verwyder vir bepaling
van chemiese samestelling, drupverlies, kookverlies, skeurwaardes en kleurbepaling. Die m.
gracilis is uit die agterbeen uitgehaal en vir sensoriese evaluering gebruik.
VM's het betekenisvolle hoër GOT's as BB'e (bv. VMHE56: 0.281; BBHE56: 0.162 kg/dag)
gehad. Binne 'n dieet was daar geen verskille (P>0.05) in VOD tussen BB'e en VM's nie en
net die VM's se VOD het tussen die LE- en HE-dieet verskil (bv. BBLE28: 7.65; BBHE28:
6.37; VMLE28: 8.73; VMHE28: 5.56 kg voer/kg gewigstoename). BBLE het die droë materiaal
(DM), ruproteïen (RP) en energie meer effektief verteer en het 'n hoër energieretensie as
VMLE gehad. Die twee diëte het dieselfde ME-waarde vir die bokke gehad, wat bevestig dat
bokke net so goed op 'n laer kwaliteit voer presteer as op 'n dieet van 'n hoër kwaliteit.
Stikstofretensie is nie deur spesie of dieet beïnvloed nie. Die BB het 'n 49% laer (P<0.01)
waterinname per kg massatoename op beide die HE- en LE-dieet gehad. Beide spesies het
'n laer (P<0.01) waterinname op die hoë as die lae energie dieet gehad. Verder het die BB
ook 'n daaglikse waterinname van slegs 171 ml/kg075 gehad in vergelyking met die 302
ml/kgO.75van die VM.
Die gewig van die lewer, leë pens, kop en pote (as persentasie van leë liggaamsgewig) was
hoër vir bokke as vir skape. Die VM's se velle was betekenisvol swaarder, waarskynlik as
gevolg van wolgroei. Beide niervet en kanaalvet het toegeneem met 'n toename in
slagouderdom. Die diere wat na 56 dae in die voerkraal geslag is, het betekensivol langer en
dieper karkasse gehad as dié na 28 dae. Binne 'n dieet en slagouderdom, het die skape
breër en dieper (P<0.05) karkasse as die bokke gehad. BB'e het betekenisvol minder gewig
per eenheid karkaslengte en dus maerder karkasse as VM's gehad. Dieet-energievlak het
geen betekenisvolle effek op die verspreiding van karkasgewig by bokke gehad nie. VM's het
egter swaarder karkasse (LE: 19.87 vs. 15.28 kg; HE: 24.01 vs. 17.05 kg) en proporsioneel
swaarder ribbes en boude as BB'e gehad.
Dieet of slagouderdom het nie 'n betekenisvolle effek op die chemiese samestelling (vog, vet,
proteïen en as) van die m. semimembransous gehad nie, maar VM's het laer (P<0.05)
vogwaardes as BB'e gehad. In die 8-9-10-rib snit het BB'e betekenisvolle hoër vog en
proteïen, maar laer vet- en energiewaardes as VM's gehad. In beide spesies het DM, vet en
energiewaardes toegeneem met 'n toename in slagouderdom. BG'e het 'n betekenisvolle
hoër konsentrasie in 11 van die 18 gemete essensiële aminosure in hul 8-9-10-rib snitte
gehad in vergelyking met VM's. Bokkarkasse het ook hoër Ca, K, Mg, N en P-vlakke as
skaapkarkasse gehad, ongeag die dieet. Daar was 'n neiging vir die bok m.
semimembranosus om 'n laer Fe-inhoud as dié van die skaap te hê. BB-karkasse het 'n laer cholesterol-inhoud as skaapkarkasse (66.77 vs. 99.28 mg/100g, onderskeidelik) gehad.
Palmitiensuur (C16:0), steariensuur (C18:0) en oleïensuur (C18:1n9) het die grootste
proporsies van die vetsure in beide die m. semimembranosus en 8-9-10-rib snit van beide
spesies uitgemaak. Op 'n LE-dieet was daar geen verskil tussen die versadigde (SFA) tot
onversadigde (UFA) vetsuur-verhouding van bok- en skaapvleis nie. Op 'n HE-dieet het
skaapvleis egter 'n betekenisvol hoër SFA:UFA-verhouding as bokvleis gehad (m.
semimembranosus: 0.842 vs. 0.689; 8-9-10-rib snit: 1.40 vs. 0.892, onderskeidelik).
Organolepties is 'n verskil tussen bok- en skaapvleis gevind. Elkeen het 'n spesifieke
spesiegeur, wat onafhanklik van die dieet was. Bokvleis is waargeneem as meer veselrig as
skaapvleis, maar daar was geen verskil in Warner-Bratzler skeurwaardes nie. In beide
spesies het sagtheid afgeneem met 'n toename in ouderdom en daar was 'n neiging vir
bokvleis om minder sappig as lamsvleis te wees. Bokvleis het ook 'n meer pertinente
nasmaak as lam gehad. Geen objektiewe verskil kon tussen die kleur van gekookte skaapen
bokvleis onderskei word nie. Daar was egter 'n tendens vir vars lamsvleis om 'n hoër a*-
waarde (rooiheid) as bokvleis te hê. Alhoewel dieet nie 'n invloed op drupverlies gehad het
nie, het drupverlies toegeneem met 'n toename in slagouderdom. Slegs na 56 dae het die VM
se m. semimembranosus 'n hoër (P>0.05) drupverlies as dié van die BB getoon (LE: 4.84 vs.
3.43%; HE: 4.72 vs. 3.32%, onderskeidelik). In die m. semimembranosus van beide spesies
het kookverlies toegeneem met 'n toename in slagouderdom.
Aangesien dieet nie 'n effek op die groei, karkasgewig-verspreiding, waterhouvermoë, kleur,
skeurwaardes of organoleptiese eienskappe van bokvleis gehad het nie, kan BB'e op 'n dieet
met 'n laer ME-waarde as wat normaalweg vir skape geformuleer word, afgerond word,
sonder om 'n verlaging in produksie te verwag. Dit mag 'n direkte ekonomiese voordeel vir
afronding van BB'e in die voerkraal inhou. Vleis van jong voerkraalbokke is nie
minderwaardig teenoor die van skape nie e-n dit het 'n hoër proteren- en laer vetpersentasie.
Dus kan bokvleis as 'n gesonde voedselbron gesien word, veralonder lae-inkomste groepe of
mense wat 'n lae kalorie-dieet wil inneem.
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Effect of feeding a fatty alcohol product to dairy cows on feed intake, digestibility, milk production and milk compositionIbbetson, Russell Wesley January 2010 (has links)
Includes bibliographical references (leaves 38-43). / Digitized by Kansas Correctional Industries
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Selection for feed conversion : direct and correlated responses and genetic parametersBlum, Josef Konrad January 2011 (has links)
Digitized by Kansas Correctional Industries
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Effects of diet on performance of pigs weaned at three weeksPope, Susan Kay January 2011 (has links)
Typescript (photocopy). / Digitized by Kansas Correctional Industries
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