M.Sc. / The amount of allozyme variation within, and the extent of genetic differentiation between, 19 sheep breeds from southern Africa were determined by six enzyme coding loci. Another eight enzyme coding loci were analyzed for five breeds. Between 55 and 66.67% of the protein coding loci were polymorphic (95% criterion) in all the breeds, except for the Namaqua sheep that were less polymorphic (33.33%). Values of 1.67 to 2.5 were obtained for the mean number of alleles per locus and average heterozygosities per locus was between 16.6 to 35.9%. The allelic constitution particularly at the transferrin (TF) locus varied appreciably for the different breeds. For example, the TF*H allele was exclusively noted in the Dormer sheep and the TF*G allele was found in the Afiino, Van Rooy, Border Leicester, Blackhead Persian and Skilder-Persian breeds. The only polymorphic breeds at the albumin locus were the South African Mutton Merino and Van Rooy breeds. The allelic constitution at the other polymorphic loci was similar for the breeds, but the allele frequencies of the South African Merino differs from Merino breeds in other countries at the TF locus. Unbiased genetic distance values were the smallest between the Dorper and Dormer breeds and the largest between the Romenof and Blackhead Persian breeds, and the mean genetic distance between the 19 breeds was 0.067. The mean amount of differentiation among the breeds relative to ' the limiting amount under complete fixation (F st) was calculated at 0.123, which is an indication of small genetic differentiation between the breeds studied. However, this , statistic is not reflected by the allele distribution that was not identical for 25 breed pairs (15%) of the total (171) at all the genetic blood systems studied. None of the breed pairs showed identical allele distributions at all the loci studied for at least one locus differed at each breed pair compared. Random amplified polimorphic DNA's gave no consistent or repeatable results. The results of the allozyme study presents the first study of the current genetic characterization of the different southern African sheep breeds.

Orientador: Felix Guillermo Reyes Reyes / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-22T02:54:44Z (GMT). No. of bitstreams: 1 Baptista_RafaeladeCarvalho_M.pdf: 1656875 bytes, checksum: e8e25ea957ad18b82ece74062e9bcd51 (MD5) Previous issue date: 2013 / Resumo: A ovinocultura vem despertando enorme interesse em todas as regiões do Brasil e sua produção destina-se, principalmente, na criação de cordeiros. Contudo, um dos grandes impasses nos sistemas de produção, especialmente em pastagens, são as parasitoses gastrointestinais. Os problemas associados com os parasitas acarretam danos à saúde dos animais, reduzindo o seu desempenho e os lucros do produtor. Como medida profilática, faz-se uso dos anti-parasitários, medicamentos veterinários com ação contra endo e ectoparasitas. Contudo, a utilização indiscriminada dos fármacos tem favorecido o desenvolvimento de estirpes resistentes responsáveis pela rápida ineficácia do composto. Como medida de controle dos nematoides gastrointestinais nas criações comerciais de ovinos, o fármaco costuma ser administrado baseando-se no resultado de duas formas de exame diagnóstico: contagem de ovos dos parasitas nas fezes e o teste FAMACHA® (exame da coloração da mucosa ocular) ou a aplicação do composto em períodos regulares de 28 dias, independente de exame. Na tentativa de determinar a melhor posologia (dose/frequência) do anti-helmíntico a ser empregado na prática, busca-se o melhor entendimento de suas propriedades farmacocinéticas, ou seja, determinar a quantidade do fármaco disponível no organismo para geração de um efeito terapêutico adequado. A moxidectina (MOX) é uma lactona macrocíclica que tem se destacado nos últimos anos pela sua eficiência anti-helmintica em baixas doses e pela longa persistência no organismo dos animais. Deste modo, o presente trabalho teve por objetivo desenvolver e validar um método analítico, empregando cromatografia líquida acoplada a espectrometria de massas (LC-ESI-MS/MS), avaliar o perfil farmacocinético da MOX no soro de cordeiros, assim como comparar as concentrações dos resíduos presentes no soro de animais submetidos a diferentes métodos de controle parasitários em condições de criação comercial em pastagens. O método analítico desenvolvido foi validado apresentando exatidão entre 80-107,3 % e valores de precisão entre 1,7-6,7 %. Os limites de detecção (LOD) e quantificação (LOQ) determinados foram de 2,0 ng mL-1 e 5,0 ng mL-1, respectivamente. Os resultados dos parâmetros de validação demonstraram que o método foi adequado para determinar a presença da MOX no soro de cordeiro. A disposição da MOX no soro foi avaliada em cordeiros da raça suffolk (n=7), após administração subcutânea de 0,2 mg kg-1 de peso corpóreo, em uma única dose. As concentrações de MOX no soro apresentaram valores de Cmáx 8,5 ± 2,81 ng mL-1, e Tmáx de 1 ± 0,7 dias. Os valores da AUC 0-8 e T1/2 foram 82,42 ± 8,02 ng dia.mL-1 e 7,66 ± 1,62 dias, respectivamente. Os resultados indicam uma absorção subcutânea lenta e, portanto, maior tempo de exposição sistêmica e menor disponibilidade do fármaco na circulação sanguínea, quando comparado com outras espécies como caprinos, bovinos ou com a ivermectina. Nenhum dos diferentes métodos de controle parasitários avaliados apresentou resíduos de MOX no soro superiores ao limite de quantificação do método / Abstract: The sheep breeding has aroused great deal of interest in all regions of Brazil and its production is mainly intended to the creation of lambs. However, the gastrointestinal parasitosis is one of the major difficulties in the production systems, especially in the field. Parasites cause animals¿ health damage, reducing their performance and the profits of the producer. As a consequence parasiticides are used as prophylactic measure. However, care on their use must be taken, since the indiscriminate use of veterinary drugs has favored the development of resistant strains, responsible for the loss of the drug effectiveness. As a control of gastrointestinal nematodes in the commercial sheep breeding, the veterinary drug is usually administered based on the result of two forms of diagnostic test: faecal egg count of parasites and the FAMACHA® test (examination of ocular mucosa color), or on the application of the veterinary drug at regular periods of 28 days, independently of any diagnostic test. In an attempt to determine the optimal dosage (dose / frequency) of the parasiticide to be used in practice, it is necessary the better understanding of their pharmacokinetic properties, in order to determine the amount of drug available in the body to generate an adequate therapeutic effect. Moxidectin (MOX) is a macrocyclic lactone that acts against endo and ecto-parasites, and has come to prominence in recent years due to its effectiveness at low doses and long persistence in the organism of the animals. Thus, the present study aimed to develop and validate an analytical method employing liquid chromatography coupled to mass spectrometry (LC-ESI-MS/MS), evaluate the pharmacokinetic profile of MOX in the serum of lambs, and to compare the MOX residue levels on the serum of animals subjected to different parasiticidal method of control in conditions of commercial breeding in the field. The validated analytical method presented between 80 to 107.3 % accuracy, and precision values between 1.7 - 6.7 %. The limits of detection (LOD) and quantitation (LOQ) were 2.0 ng mL-1 and 5.0 ng mL-1, respectively. The results of the validation parameters showed that the method was suitable to determine the presence of MOX in the lamb serum. The pharmacokinetic profile of MOX was evaluated in suffolk race lambs (n = 7), after a single subcutaneous dose administration of 0.2 mg kg-1 body weight. The serum concentrations of MOX showed Cmax value of 8.5 ± 2.81 ng mL-1, and Tmax of 1 day. The AUC0-8 and the T1/2 were 82.42 ± 8.02 ng day.mL-1 and 7.66 ± 1.62 days, respectively. The results indicated a slow MOX subcutaneous absorption and, therefore, increased systemic exposure time and low availability of the drug in blood circulation, when compared to other species such as goats or cattle, or to ivermectin. None of the different parasiticidal control methods evaluated showed MOX residue levels above the LOQ of the analytical method / Mestrado / Ciência de Alimentos / Mestra em Ciência de Alimentos

Thesis (M. Tech. Agriculture) -- Central University of Technology, Free state, 2012 / Low lifetime rearing success and high perinatal mortality have been associated with small pelvic areas of ewes. Ewes with small pelvic areas are more prone to experience dystocia during parturition and high perinatal mortality. It would thus make sense to include pelvic area as criterion in selecting breeding animals (rams) in an attempt to assure bigger pelvic areas in the female progeny as the heritability of pelvic area ranges between 50-60%. The aims of this study were to develop two instruments to accurately measure the pelvic area and rump slope in small stock, to investigate the hindquarter dimensions and to quantify the relationship between a number of easy to measure external body measurements and pelvic dimensions of Dorper sheep. The pelvic meter developed was pre-tested on 90 sheep prior to slaughtering at an abattoir and shortly after slaughter. The correlation between the pre- and post- slaughter measurements was highly significant (P <0.05; r = 0.85). In this study 272 Dorper and White Dorper rams (5-7 months of age) participating in the Northern Cape Veldram project and 332 young Dorper and White Dorper ewes (±12 months of age) from three different breeders were measured. The inside pelvic area was measured trans-rectally. The rams’ pelvic areas were measured five times transrectally, at 40 days intervals between the ages of 223 ± 41 and 385 ± 41 days of age. The height of the pelvis was obtained by measuring the distance between the dorsal pubic tubercle on the floor of the pelvis and the sacrum (spinal column) on the top. The width of the pelvis was measured as the widest distance, between the right and the left shafts of the ilium bones. The pelvic area was calculated using the π (PH/2)*(PW/2) formula. Other linear body measurements (body height, shoulder height, chest depth, forequarter width, hindquarter width, rump length) as well as body weight were taken. The rams’ rump slope was measured in degrees with an instrument that was developed for this purpose, and the ewes’ rump slope was visually scored on a scale from 1-5 with one being very flat and five being very droopy. The overall mean pelvic area of ewes 35.44 ± 4.89 cm2 and those of the rams 28.22 ± 3.21 cm2 differed with 7.22 cm2. Stud ewes recorded significantly larger (P <0.05) pelvic areas (37.38 ± 4.3 cm2) than commercial ewes (33.92 ± 3.77cm2). Results indicated that there are no significant correlations between pelvic dimensions and other body measurements considered in this study, indicating the need to measure pelvic area directly. Both the pelvic meter and rump slope meter, specially developed for this study, proved to be accurate and relatively practical to use in Dorper sheep.

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: Fluctuations and a general decline in the ratio between wool and meat prices resulted in marked changes in the South African sheep industry. Commercial producers now exploit other mechanisms such as terminal crossbreeding of Merino-type with meat type breeds or dual-purpose breeds to attain short-term benefits resulting from price fluctuations between wool and mutton without compromising the wool-producing capacities of ewe flocks. Most components of lamb production have low heritability. However, heterosis can be achieved by mating wool-type breeds with specialist meat breed rams. Genetic improvement of livestock depends on defining breeding objectives, estimation of genetic parameters and accurately identifying the right animals to be used for future breeding. Genetic parameters for traits of economic importance in terminal sire sheep breeds that could be used on Merino-type ewes in commercial operations in South Africa had not been published for the national flock apart from a preliminary study having been conducted by Olivier et al. (2004). Selection objectives were poorly defined due to lack of parameter estimates for variance and covariance components. Against this background, this study obtained pedigree information and live weight data from the National Small Stock Improvement Scheme for the Dormer, Ile de France and Merino Landsheep and estimated non-genetic factors and genetic parameters influencing early growth traits. Genetic and phenotypic trends for early growth traits were constructed for the three breeds to monitor genetic progress. Non-genetic factors influencing early growth traits in the Dormer, Ile de France and Merino Landsheep were estimated using data obtained from the National Small Stock Improvement Scheme of South Africa. The original data sets for the Dormer, Ile de France and Merino Landsheep consisted of the following number of records respectively: 52 202, 35 553 and 7 772. However, pre-weaning weights were available for the Ile de France and Merino Landsheep breeds only and post-weaning weights were available only for the Dormer breed. The data sets were complicated to such an extent that smaller data sets had to be generated to analyse for fixed effects. The traits that were analysed were birth weight, pre-weaning weight, weaning weight and post-weaning weight. The fixed effects, identified as having a significant effect (P < 0.01) on early growth traits were sex of lamb, birth type, age of dam, contemporary groups, age at which the trait was recorded and month of birth and year of birth in the Merino Landsheep breed. Although some significant interactions were found, they were subsequently ignored owing to their very small effects. In all three breeds, male lambs were significantly (P < 0.001) heavier than female lambs and single-borne lambs were significantly heavier at birth than multiple borne lambs. The age of dam had a significant curvilinear regression on all early growth traits in all three terminal sire sheep breeds. It was concluded from the study that the influence of non-genetic factors on early growth traits should be adjusted for or eliminated statistically in genetic evaluations to get accurate genetic parameter estimations. (Co)variance estimates for birth weight, weaning weight and post-weaning weight were obtained for the Dormer breed using restricted maximum likelihood procedures (REML). Direct heritabilities (h2) in single-trait analyses were 0.21 ± 0.03, 0.23 ± 0.02 and 0.29 ± 0.05 for birth weight, weaning weight and post-weaning weight, respectively. Direct heritabilities of 0.28 ± 0.04, 0.55 ± 0.06 and 0.32 ± 0.02 for birth weight, weaning weight and post-weaning weight respectively were obtained using three-trait analysis. Direct maternal genetic effects (m2) were excluded from the analyses because of the failure to partition maternal effects into maternal genetic and maternal permanent environmental effects (m2 and c2). This culminated as a consequence of poor data and population structures emanating from the loss of genetic links across flocks due to the random entrance and exit of flocks from the recording scheme. Maternal permanent environment was estimated at 0.15 ± 0.02, 0.13 ± 0.02 and 0.20 ± 0.03 for birth weight, weaning weight and post-weaning weight respectively using single-trait analysis. The correlation between direct effects and maternal effects (ram) was excluded from the analyses due the structure of the data. Genetic, phenotypic and environmental correlations between early growth traits were low to moderate. The medium to high heritability estimates for early growth traits obtained in the study led to the conclusion that Dormer sheep can successfully be used in terminal crossbreeding programs to improve meat production characteristics. Direct heritability estimates were 0.31 ± 0.14, 0.09 ± 0.02 and 0.14 ± 0.003 for birth weight, pre-weaning weight and weaning weight respectively using single-trait analysis for the Ile de France breed. Maternal effects were significant for all the traits studied despite the failure to properly partition them into their components due to the loss of genetic linkages across generations emanating from poor data structure. Genetic, phenotypic and environmental correlations were estimated using three-trait analysis and were found to be low to moderate for early growth traits. Direct genetic and maternal permanent environmental ratios were also computed and they did not differ much from the results obtained using single-trait analyses. The reasonable genetic parameter estimates obtained in the study led to the conclusion that the Ile de France can be selected to use as sires in crossbreeding programs. Genetic parameters were estimated for early growth traits in the Merino Landsheep breed. REML estimates of birth weight, pre-weaning weight and weaning weight were obtained using animal models in single-trait analyses. The direct heritability estimate for birth weight was 0.23 ± 0.13 using an animal model with additive direct genetic effects and dam permanent environmental effects as the only random factors. The dam permanent environmental effect for birth weight amounted to 0.10 ± 0.07. Direct heritability for pre-weaning weight was 0.36 ± 0.05 and the dam permanent environmental effect 0.56 ± 0.03. Weaning weight was estimated using an animal model that contained direct additive effects and dam permanent environmental effects. The direct heritability estimate for weaning weight was 0.17 ± 0.03. Maternal genetic effects were estimated to be 0.02 ± 0.01. Genetic and phenotypic trends were constructed for early growth traits in the Dormer, Ile de France and Merino Landsheep breeds. The traits that were considered were birth weight, pre-weaning weight, weaning weight and post-weaning weight. However, pre-weaning weights were available for the Ile de France and Merino Landsheep breeds only and post-weaning weights were available only for the Dormer breed. The Dormer exhibited significant improvement in the phenotypic and genetic aspects of early growth traits during the 17 years of evaluation (1990-2007). The average predicted direct breeding values of birth weight decreased by 0.055 % during the evaluation period. The predicted direct breeding value for weaning weight increased by 0.12 % during the 17 year period. Post-weaning weight improved by 0.32 % per annum. The Ile de France registered an increase in the predicted breeding value of birth weight which amounted to 0.025 % per annum. Averaged direct breeding values for pre-weaning weight increased at an annual rate of 0.23 %. and that of weaning weight increased by 1.21 %. In the Merino Landsheep the predicted direct breeding value for birth weights decreased by 0.04 % per annum and pre-weaning and weaning weights increased by 0.36 % and 0.10 % respectively. The trends were obviously biased due to inconsistencies in data structure and very few records available for analysis in this breed. In conclusion, it was evident that the additive genetic variation was available for all the early growth traits in all the three breeds. Although adequate genetic variation for substantial genetic progress was available, only modest rates of progress were attained for all the traits in all three breeds. The only possible exception was weaning weight in the Ile de France breed, which improved at > 1 % per annum. At least all changes were in the desired direction. Breeders should be encouraged to record data consistently, as one of the major shortcomings in the data for all breeds were a lack of continuity in the submission of data to the NSIS. More informative analyses ought to be feasible if this requisite could be met. / AFRIKAANSE OPSOMMING: Die wisselende en algemene afname in die prysverhouding van wol tot vleis het merkbare veranderinge in die Suid-Afrikaanse skaapbedryf teweeggebring. Kommersïele produsente maak nou gebruik van ander metodes soos terminale kruisteling van Merino-tipe ooie met vleis tipe vaars of dubbel-doel rasse om korttermynvoordele uit die wisselende wol en vleis pryse te behaal, sonder om die wol-produksie potensiaal van die ooi-kudde te benadeel. Die meeste van die lamproduksie eienskappe het ‘n lae oorerflikheid. Nietemin, kan heterose wel behaal word deur die kruisteling van wol-tipe rasse met spesialis vleisramme. Genetiese verbetering van vee is afhanklik van die beskrywing van die teeltdoelwitte, die akkurate beraming van genetiese parameters en die noukeurige identifikasie van die geskikste diere vir toekomstige teling. Genetiese parameters vir ekonomies belangrike eienskappe van terminale ramrasse wat gebruik kan word op Merino-tipe ooie in die kommersiële skaapbedryf in Suid-Afrika is nog nie gepubliseer vir die nasionale kudde nie, behalwe vir ‘n voorlopige studie wat gedoen is deur Olivier et al. (2004). Seleksiedoelwitte is nie duidelik beskryf nie a.g.v ‘n tekort aan akkurate parameterberamings vir (ko)variansie komponente. Hierdie studie het dus stamboominligting en lewende gewig data verkry vanaf die Nasionele Kleinveeverbeteringsskema vir die Dormer-, Ile de France- en die Merino landskaaprasse en nie-genetiese faktore sowel genetiese parameters vir vroeë lamgewigte beraam. Genetiese en fenotipiese tendense vir vroeë lamgewigte is vervolgens opgestel vir drie rasse om genetiese vordering te evalueer. Die oorspronklike datastelle vir die Dormer, Ile de France en die Merino Landskaap het uit die volgende aantal rekords bestaan, onderskeidelik: 52 202, 35 553 en 7 772. Voor-speen gewigte was net beskikbaar vir die Ile de France- en die Merino Landskaaprasse, en na-speen gewigte was net beskikbaar vir die Dormerras. Die beperkings in die datastelle het genoodsaak dat dat kleiner datastelle ontwikkel moes word om die vaste effekte te analiseer. Die eienskappe wat ge-analiseer was, was geboortegewig, voor-speengewig, speengewig en naspeengewig. Die vaste effekte wat vroeë lamgewigte betekenisvol (P < 0.01) beïnvloed het, was geslag van die lam, geboortestatus, ouderdom van die ooi, kontemporêre groep, die ouderdom waarop die eienskap aangeteken is en (in sommige gevalle) die maand en jaar van geboorte. Alhoewel daar sommige betekenisvolle interaksies was, is dit nie in die finale modelle ingesluit nie, omdat dit min tot die verklaarde variasie bygedra het. In al die rasse het ramlammers swaarder (P < 0.001) geweeg as ooilammers. Enkelinge was ook swaarder (P<0.001) as meerlinge. Die ouderdom van die moer van die lam het ‘n beduidende kromlynige invloed op alle vroeë lamgewigte by al drie terminale ramrasse gehad. Die gevolgtrekking van hierdie studie is dat die invloed van nie-genetiese faktore op vroeë lamgewigte in ag geneem moet word, of dat dit moet statisies elimineer word in die genetiese evaluasie om akkurate genetiese beramings te verkry. (Ko)variansie beramings vir geboortegewig, speengewig en na-speengewig is deur gebruik te maak van die “restricted maximum likelihood procedures” (REML) vir die Dormerras verkry. Die direkte oorerflikheid (h2) wat verkry was deur die mees geskikste diere model in ‘n enkel-eienskap analise te gebruik was onderskeidelik 0.21 ±0.02, 0.23 ±0.02 en 0.29± 0.05 vir geboortegewig, speengewig en na-speengewig. Direkte ooreenstemende oorerflikheid wat uit die drie-eienskap analise was 0.28±0.04, 0.55±0.06 en 0.32±0.02 onderskeidelik vir geboortegewig, speengewig en na-speengewig. Direkte maternale genetiese effekte (m2) is uitgesluit vanaf die analise weens die onvermoë om die maternale effekte te verdeel in maternale genetiese effekte en maternale permanente omgewings effekte (m2 en c2). Dit was a.g.v onvolledige data en populasiestrukture wat gelei het tot die gebrek in genetiese bande oor kuddes, wat ontstaan het weens kuddes wat slegs tydelik data tot die skema bygedra het. Maternale permanente omgewingeffekte is geskat op onderskeidelik 0.15±0.02, 0.13±0.02 en 0.20±0.03 vir geboortegewig, speengewig en na-speengewig met die gebruik van die enkel-eienskap analise. Die korrelasie tussen direkte effekte en maternale effekte (ram) is uitgesluit a.g.v die gebrekkige struktuur van die data. Genetiese-, fenotipiese- en omgewingskorrelasies tussen die vroeë lamgewigte was laag tot matig. Die matige tot hoë oorerflikheidberamings vir vroeë lamgewigte uit hierdie studie het gelei tot die gevolgtrekking dat Dormer skape suksesvol gebruik kan word in terminale kruisteel programme om vleisproduksie te verbeter. Direkte oorerflikheid skattings was 0.31±0.14, 0.09±0.02 en 0.14±0.003 vir die geboorte gewig, voor-speen gewig en speen gewig onderskeidelik met die gebruik van ‘n enkel-faktor analise vir dir Ile de France skaap ras. Maternale effekte was beduidend vir al die eienskappe wat bestudeer was , ten spyte van die onvermoë om dit behoorlik te verdeel in hul komponente weens die verlies van genetiese bande dwarsoor die generasies wat uitvloei vanaf ‘n swak data struktuur. Genetiese, fenotipiese en omgewings korrelasies was geskat deur gebruik te maak van ‘n drie-faktor analise en was gevind om laag tot matig te wees vir die vroeë groei eienskappe. Direkte genetiese en maternale permanente omgewings ratios was bereken en dit het nie veel verskil van die resultate verkry deur die enkel-faktor analise. Die aanvaarbare genetiese parameter skattings verkry in hierdie studie het gelei tot die gevolgtrekking dat die Ile de France geselekteer kan word as teelramme in kruisteel programme. Genetiese parameters was geskat vir vroeë groei eienskappe in die Merino Landskaa ras. REML skattings van geboorte gewig, voor-speen gewig en speen gewig was verkry deur diere modelle in enkel-faktor analises. Die direkte oorerflikheid skatting vir geboorte gewig was 0.23±0.13 met die gebruik van die diere model met additiewe direkte genetiese effekte en ooi permanente omgewings faktore as die enigste ewekansige faktore. Die ooi permanente omewings effek vir geboorte gewig was 0.10±0.07. Direkte oorerflikheid vir voor-speen gewig was 0.36±0.05 en die ooi permanente omgewings effek 0.56±0.03. Speen gewig was geskat deur die gebruik van ‘n diere model wat die direkte additiewe effekte en die ooi permanente omgewings effekte bevat het. Die direkte oorerflikheids skatting vir speen gewig was 0.17±0.03. Maternale genetiese effekte was geskat as 0.02±0.01. Genetiese en fenotipiese tendense is verkry vir vroeë lamgewigte in die Dormer-, Ile de France- en Merino Landskaaprasse. Die eienskappe wat oorweeg is, was geboortegewig, voor-speengewig, speengewig en naspeengewig. Voor-speengewigte was net beskikbaar was vir die Ile de France- en die Merino Landskaap rasse en die na-speense gewigte net vir die Dormerras. Die Dormer het beduidende verbetering vertoon in die fenotipiese en genetiese aspekte vir vroeë lamgewigte gedurende die 17 jaar van evaluasie (1990-2007). Die gemiddelde voorspelde direkte teeltwaarde van speen gewig het met 0.12% per jaar gestyg gedurende die 17- jaar periode. Na-speen gewig het met 0.32% per jaar verbeter. By die Ile de France het ‘n toename in die voorspelde teelwaarde van geboortegewig (0.025% per jaar) voorgekom. Gemiddelde direkte teelwaardes vir voor-speengewig het toegeneem teen ‘n jaarlikse tempo van 0.23% en speengewig het met 1.21% per jaar toegeneem. In die Merino Landskaapras het die voorspelde direkte teelwaarde vir geboortegewig met 0.04% per jaar gedaal, terwyl voor-speen- en speengewigte met 0.36% en 0.10% onderskeidelik toegeneem het. Die tendense was ooglopend gekompromiteer weens probleme met die data struktuur, en a.g.v van die relatief min rekords wat beskikbaar was vir die analise in die ras. Dit was duidelik dat die additiewe genetiese variasie beskikbaar was vir al die vroeë groei eienskappe in al die drie rasse. Alhoewel voldoende genetiese variasie vir wesentlike genetiese vordering beskikbaar was, is daar slegs matige vordering verkry vir al die eienskappe in al drie rasse. Die enigste moontlike uitsondering was speengewig in die Ile de France ras, wat met 1.21 % per jaar gestyg het. Alle veranderinge was minstens in die gewensde rigting. Telers word versoek om data deurlopend en akkuraat aan te teken , aangesien een van die groot tekortkominge met die data van al die rasse ‘n tekort aan deurlopendheid in die indiening van die data aan die NISS was. ‘n Meer verteenwoordigende analise sal uitvoerbaar wees, as daar aan al die bogenoemde aanbeveling voldoen kan word.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniviversitet, 2006. / Härtill 7 uppsatser.

Includes bibliographical references (leaves 325-341). / xxvii, 341 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Skin and fleece measurements were recorded at different ages for both male and female sheep from the Turretfield Merino Resource Flock and used to estimate the heritability of each trait and the phenotypic and genetic correlations among and between the skin and fleece traits. Generally, the heritability of each trait was high, which indicates that both the fleece and skin traits should respond well to selection. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Science, 2001

The Nguni sheep of Zululand, South Africa, are called the Zulu sheep. They are a source of food and cash for the rural farmers of KwaZulu-Natal. There is insufficient information available about the characteristics of this breed and accordingly the breed is classified as “insecure”. Documentation of characteristics of a breed is important for its utilisation, improvement or conservation. This study was undertaken to document (i) the utilization of the Zulu sheep, (ii) some morphological characteristics, (iii) establishing a cost effective body measurement recording means and (iv) the intra- and inter-population genetic variation of the breed using random amplified polymorphic DNA markers. A survey was conducted to investigate the socio-economic and cultural values of the farmers attached to livestock including the Zulu sheep. A total of 76 rural farmers were interviewed in the areas of the Mhlathuze district in northern KwaZulu-Natal. Constraints and the indigenous knowledge of the farmers on livestock production were also recorded. The results confirmed that the Zulu sheep in the rural areas are indeed used as a source of protein and cash when necessary. Farmers reported that the Zulu sheep are tolerant to ticks and able to withstand the hot and humid conditions of northern KwaZulu-Natal. Goats and cattle as well as the Zulu sheep are also used for payment of dues in the tribal courts. Even so, Zulu sheep are not used for any cultural purposes. The system of management is fairly extensive. Some farmers apply indigenous knowledge as part of management practices. For instance, they use indigenous plants as nutrient supplements and for increasing the reproduction rate of these animals. Lack of modern animal husbandry skills was declared by the farmers as one of the main challenges. A perception among the farmers was that the Government could assist in addressing this challenge. Three populations of Zulu sheep reared extensively in three localities were used for the morphometric and genetic studies. The areas were the community of KwaMthethwa (Enqutshini), University of Zululand (UNIZULU) and Makhathini Research Station. Makhathini and KwaMthethwa are 260 and 40 km, respectively, away from UNIZULU. The morphometric study was undertaken to determine the extent of phenotypic diversity between Zulu sheep populations using six morphological characteristics. Effects of some factors (location, age, sex and season) on some of these traits were estimated. Results showed that the size of the body measurements, wither height (WH), heart girth (HG), live weight (LW) and scrotal circumference (SC) were significantly different between the populations. Variation in these body measurements was influenced significantly by the location, season, the sex and the age of sheep. Mature ewes weighed up to 32 kg whereas the rams weighed up to 38 kg. The differences in LW, HG and WH between the seasons were small. The SC increased with the age of the ram up to 28 cm for mature rams. Other traits observed were the colour and the ear length of Zulu sheep. Ear size ranged from ear buds to the most common large ears (9 to 14 cm). The dominating colours observed were brown and a combination of brown and white. Live weight prediction equations were estimated employing HG, WH and SC data. The LW prediction equations showed that the regression of HG and WH produce the best estimate equations of LW; however the HG alone also showed reliable LW estimates. Scrotal circumference was more precise for estimating the LW of younger rams below 22 months of age (R2 = 0.64 – 0.78). Fifty-two Zulu sheep from the three locations were used to assess the genetic variation within the Zulu sheep breed. A total of 2744 RAPD bands were generated ranging from 0.2 to 2 kb; ~46% of these bands were polymorphic. The genetic diversity was the lowest (5.17%) within the UNIZULU population, 8.62% within the KwaMthethwa population and highest (11.04%) within the Makhathini population. The genetic diversity between all populations was estimated at 21.91 %. Phenotypic diversity was relatively similar for the UNIZULU and Makhathini populations (41.25% and 45.63%, respectively). The phenotypic diversity between the three populations was 48.26%. Genetic and phenotypic diversity was lower for Makhathini and UNIZULU populations than for the KwaMthethwa population. It was concluded that the Zulu sheep is a smaller sized breed compared to the other South African indigenous sheep breeds like the Dorper which has been reported to have some similar characteristics to the Nguni sheep. The results confirmed that the Zulu breed has the capacity to survive without dipping and supplements during the dry season. This adaptation is of value to the communities of KwaZulu-Natal. Such characteristics warrant conserving the breed to prevent genetic erosion. The phenotypic and genetic diversity between the three populations of Zulu sheep may indicate that there is an opportunity of genetic exploitation by selecting animals based on phenotypic as well as genetic characteristics. In order to promote the conservation and sustainable use of the Zulu sheep, it was recommended that an open nucleus breeding scheme from lower-tier flocks (of the farmers) for pure breeding to nucleus flocks (in Government ranches) could be appropriate. The scheme would also address the challenges of animal husbandry as well as contribute to the improvement of the livelihood of the farmers. Farmers could use a tape measure to estimate the LW of sheep when they cannot afford scales. The morphological characteristics and the genetic diversity data generated from this study could be combined into a single data base for this sheep breed. More extensive studies, using the same or some additional phenotypic characters such as reproductive performance, need to be done. Genetic characteristics of Zulu sheep using microsatellites and mitochondrial DNA should be done to complement the present study. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.

Thesis (MScEng (Industrial Engineering))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: In terms of its contribution to the agricultural economic activity in Namibia, the small stock industry is the most important sector, second only to the beef industry. This sector makes a significant contribution to the agricultural business in Namibia due to the sector’s exports, its provision of employment, use of natural resources, contribution to GDP and to consumer spending as well as food security. Agricultural activities in Namibia contributed 5.5 percent to Namibia’s GDP, while 70 percent of the population relies on agriculture for employment and day-to-day living. Livestock farming in Namibia is free ranging on natural pastures and therefore produces high-quality meat that is in high demand in both the national and international markets. Small stock production in Namibia is unstable due to the high variability of weather patterns, changes in economic and social environments, unpredictable droughts as well as political and structural changes. Due to the decline in mutton production over the last years, research in the supply economics of the mutton industry in Namibia is important. The purpose of this study is to investigate the relationships between the various price and non-price factors contributing to the supply dynamics within the mutton industry in Namibia. Two hypotheses are tested with the aid of econometric modelling techniques on monthly time series data. The Autoregressive Distributed Lag approach to co-integration was used to determine the long-run and short-run supply response elasticities towards economic and climatology factors. Results showed a significant long-run relationship between the average Namibian mutton producer price and mutton supply. Results revealed that a one percent increase in the mutton producer price leads to a 1.97 percent increase in mutton supply. Beef producer price, a substitute product to mutton, showed a significant negative long-run effect towards mutton production whereas rainfall showed a meaningful positive long-run contribution to mutton supply. These supply shifters towards mutton production also showed significant short-run elasticities. Results further revealed that the system takes nearly two months to recover to the long-run supply equilibrium, should any disturbances occur within the supply system. The study showed that price-related and climatological factors play a major role in the Namibian mutton production industry. Industry stakeholders and policy makers should therefore incorporate these significant relationships between supply shifters and production output into future decisions and marketing policies to secure a healthy, growing and sustainable mutton industry in Namibia. / AFRIKAANSE OPSOMMING: In terme van bydrae tot die landboubedryf in Namibië is die kleinveebedryf die tweede belangrikste sektor, net kleiner as die land se grootveebedryf. Die sektor maak ‘n betekenisvolle bydrae tot die landboubedryf in Namibië deur middel van werkskepping, die gebruik van natuurlike hulpbronne, bydrae tot Bruto Binnelandse Produk, uitvoere, verbruikersbesteding sowel as voedselsekerheid. Landbou-aktiwiteite dra by tot 5,5 persent van die Bruto Binnelandse Produk van ‘n land waar meer as 70 persent van die bevolking afhanklik is van landbou om ‘n bestaan te kan maak. Veeboerdery in Namibië geskied ekstensief op natuurlike veld wat lei tot die produksie van ‘n hoë kwaliteit produk, wat hoog in aanvraag is in plaaslike en internasionale markte. Kleinvee produksie in Namibië is onstabiel as gevolg van fluktuasies in weerpatrone, veranderings in ekonomiese en sosiale omgewings, onvoorspelbare droogtes asook politieke- en struktuurveranderinge. As gevolg van die huidige afname in skaapvleis produksie is navorsing in die aanbodkantekonomie van die skaapvleisbedryf belangrik in Namibië. Die doel van hierdie studie is om die verwantskap te ondersoek tussen verskeie prys en nie-prys faktore wat bydra tot die aanboddinamika van die skaapvleisbedryf. Twee hipoteses word getoets met behulp van ekonometriese modelleringstegnieke op maandelikse tydreeksdata. ‘n Outoregressiewe verspreide sloeringbenadering tot ko-integrasie is gebruik om die langtermyn en korttermyn elastisiteite tussen ekonomiese en klimaatsfaktore vir die aanbod van skaapvleis te bepaal. Resultate dui op ‘n betekenisvolle langtermyn verwantskap tussen die gemiddelde Namibiese produsente prys en skaapvleis produksie. Resultate wys daarop dat ‘n een persent styging in skaapvleis produsente prys ‘n 1,97 persent styging in skaapvleis aanbod het. Die beesvleis produsente prys, ‘n substituut vir skaapvleis, het ‘n beduidende negatiewe effek getoon oor die langtermyn op skaapvleis produksie. Reënval het ‘n beduidende positiewe bydrae getoon ten opsigte van skaapvleis aanbod. Hierdie aanbodsfaktore het betekenisvolle korttermyn elastisiteite getoon. Resultate het ook getoon dat die stelsel twee maande neem om te herstel tot die langtermyn aanbodsewewig, sou daar enige drastiese veranderings in die stelsel plaasvind. Die studie het getoon dat prysverwante en klimaatsfaktore ‘n uiters prominente rol speel met betrekking tot skaapvleisproduksie in Namibië. Bedryfsaandeelhouers en politieke leiers sal hierdie betekenisvolle verwantskappe tussen produksie faktore en aanbod uitset in ag moet neem in toekomstige beplanning en bemarkingsbeleid om ‘n gesonde, groeiende en volhoubare skaapvleisbedryf in Namibië te verseker.

Made available in DSpace on 2016-12-23T13:53:39Z (GMT). No. of bitstreams: 1 Charlene Candida Rangel.pdf: 1085244 bytes, checksum: 6b18f8fb4c9d2fe96407a55dc3d6f2df (MD5) Previous issue date: 2013-11-28 / Objetivou-se avaliar os efeitos das dietas com e sem a inclusão de extrato etanólico de própolis Verde Alecrim no consumo de matéria seca, nos parâmetros de perfil metabólico sanguíneo e nas inter-relações com aspectos reprodutivos. Os tratamentos utilizados foram: Controle (TC) dieta controle; Flushing (TF), dieta controle mais 300 g de fubá de milho; Flushing com nível 1 de própolis (TFP1), TF mais 8 mL de solução alcoólica de própolis/animal/dia; Flushing com nível 2 de própolis (TFP2), TF mais 12 mL de solução alcoólica de própolis/animal/dia. Foram utilizadas 16 fêmeas nulíparas vazias, sendo quatro por tratamento, distribuídas em experimento inteiramente casualizado, submetidas a um protocolo de sincronização de cio e posteriormente cobertas. Os animais foram estabulados por um período de adaptação de 10 dias, seguido de 30 dias de período experimental e alimentados duas vezes ao dia, às sete e 16 horas. Para determinar o perfil hematobioquímico, amostras de sangue foram coletadas a cada cinco dias, sendo a primeira coleta realizada com os animais em jejum e a segunda, duas horas após a alimentação das sete horas da manhã, durante 15 dias na fase pré cobrição e 15 dias na pós cobrição, para estimar os teores de ureia, proteínas totais, albumina, globulinas e a enzima AST. Utilizou-se ultrassonografia para confirmação de prenhez trinta dias após cobrição. Verificou-se que o tratamento com menor concentração de extrato etanólico de própolis Verde Alecrim apresentou potencial para diminuir consumo de MS e que o extrato etanólico de própolis demonstrou ser eficiente na diminuição do consumo de matéria seca e na concentração de ureia sérica. Os tratamentos TC, TF e TFP1 apresentaram mesma taxa de prenhez, superior ao TFP2, contudo o TFP1 resultou em maior taxa de partos gemelares. O tratamento com menor concentração de própolis reduziu a concentração de ureia sérica nos momentos jejum e duas horas após alimentação e na fase pós cobrição. Os teores dos metabólitos, em sua maioria, encontram-se dentro dos limites de valores de referência / The aim of this research was to evaluate diets with and without inclusion of propolis ethanolic extract Verde Alecrim on dry matter intake, metabolic profile and its relationships of reproductive aspects and to compare metabolic profile values with reference values established on the scientific literature. Treatments were: Control (CT), control diet; Flushing (FT), control diet plus 300 g/animal/day of corn meal; Flushing with level 1 of propolis (FTP1), FT plus 8 mL/animal/day of propolis ethanolic extract; Flushing plus level 2 of propolis (FTP2), FT plus 12 mL/animal/day of propolis ethanolic extract. Sixteen Santa Inês nulliparous ewes, empty, four per treatment, were assigned in a complete randomized design, in a factorial scheme and subjected to an estrus synchronization protocol and covered. The females were housed and the experiment consisted of an adjustment period of ten days, followed by an experimental period of 30 days (15 days for pre-mating and 15 days for post mating). Animals were fed twice a day at 7 AM and 4 PM. To determine the hematobiochemical profile, blood samples were collected at each five days in fasting and two hours after during 15 days in the pre-mating phase and 15 days in the post mating to estimate urea, total protein, albumin, globulins and AST enzyme contents. Ultrasound to confirm pregnancy thirty days following mating was used. It was found that treatment with lower concentrations of propolis ethanol extract Verde Alecrim presented the potential to decrease DM intake intake and that the ethanol extract of propolis has proved effective in decreasing the dry matter intake and concentration of serum urea. The CT, FT and FP1T provided the same pregnancy rate, superior to TFP2, however FP1T resulted in higher rate of twin births. Treatments with a lower concentration of propolis reduced urea content in serum in fasting and two hours after feeding and in the post-mating phase. Most of metabolite contents were within reference values, according to the literature

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No. of bitstreams: 1 spasiani_pp_me_jabo.pdf: 1094137 bytes, checksum: 1880f9b0c1c104145166d750bbad626e (MD5) Previous issue date: 2016-03-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Esse estudo teve como objetivo identificar e quantificar as diferenças na emissão de metano, consumo e digestibilidade aparente de ovinos mantidos em pastos de capim-massai (Panicum maximum x Panicum infestum) em sistema silvipastoril sob lotação intermitente com diferentes espaçamentos arbóreos. O experimento foi conduzido no setor de Forragicultura e Pastagens da FCAV, UNESP Jaboticabal, SP, no período de janeiro a julho de 2015. Os tratamentos foram constituídos de dois espaçamentos entre árvores de eucalipto (Eucalyptus urophylla x Eucalyptus grandis) (6,0m x 1,5m e 12,0m x 1,5m) em sistema silvipastoril (E6 e E12, respectivamente), e um tratamento que permaneceu sem árvores (SA). Foram utilizados ovinos adultos, manejados sob lotação intermitente. Como critério de entrada dos animais no pasto, foi utilizada a medida de 95% de interceptação luminosa do capim-massai. Como critério de saída, foi utilizada a altura de 20 cm da planta forrageira. O delineamento experimental foi inteiramente casualizado, com três tratamentos (arranjos arbóreos) e seis repetições (piquetes) no caso das variáveis de altura e massa do capim-massai e cinco repetições (animais) das variáveis de digestibilidade, consumo e emissão de metano (CH4). Os pastos foram avaliados em épocas do ano (águas e seca). Foi realizada a análise de contrastes ortogonais (1º e 2º graus) para os ciclos de pastejo e teste de médias Tukey para espaçamentos arbóreos (α=5%). Houve diferença significativa (p<0,05) entre os tratamentos para altura do dossel forrageiro, relação entre massa seca de forragem verde:morta e massa seca de forragem do pré e pós pastejo nos três ciclos, sendo o tratamento E6 o que apresentou os menores (p<0,05) valores em relação aos demais tratamentos. Houve interação significativa (p<0,05) entre os ciclos de pastejo e espaçamentos arbóreos para as médias de digestibilidade aparente da matéria seca (DMS). As médias de DMS do ciclo de julho foram maiores (p<0,05) do que as do ciclo de março. No ciclo de julho as médias de DMS variaram entre os espaçamentos arbóreos sendo no tratamento SA maiores (p<0,05) que o tratamento E6. Houve interação significativa (p<0,05) entre os ciclos de pastejo e espaçamentos arbóreos para as médias de consumo de forragem e de energia. O consumo de matéria seca (CMS) foi maior no ciclo de pastejo de julho. Houve diferença significativa (p<0,05) entre os espaçamentos arbóreos somente nas médias de CMS, consumo de energia bruta (CEB) e consumo de energia digestível (CED) do ciclo de pastejo de julho, onde o tratamento SA apresentou maiores (p<0,05) médias em relação ao tratamento E6. Houve interação significativa (p<0,05) entre os ciclos de pastejo e espaçamentos arbóreos nas médias de emissão de CH4 pelos animais por dia e por ano (CH4dia e CH4ano). No ciclo de pastejo de julho, as médias de CH4dia e CH4ano foram maiores (p<0,05) em comparação com as médias de março. As variáveis de emissão de CH4 por unidade de consumo apresentaram diferenças significativas apenas para ciclo de pastejo, onde julho apresentou menores (p<0,05) valores de emissão e CH4 por kg de matéria seca consumida, por energia bruta consumida e por energia digestível consumida, quando comparado às emissões do ciclo de pastejo de março. / This study aimed to identify and quantify the differences in methane (CH4) emission, intake and apparent digestibility of sheep kept in massaigrass pastures (Panicum maximum x Panicum infestum) in silvopastoral system under intermittent stocking with different arboreal spacings. The experiment was conducted at the Forage and Pastures sector of FCAV, UNESP Jaboticabal, SP, from January to July 2015. The treatments consisted of two spacings between eucalyptus trees (Eucalyptus urophylla x Eucalyptus grandis) (6,0m x 1,5m and 12,0m x 1,5m) in silvopastoral system (E6 and E12, respectively), and a treatment that remained treeless (TL). Adult sheep, managed under intermittent stocking were used. As animals enter criteria in the pasture was used to measure 95% light interception of massaigrass. As exit criteria, it used the height of 20 cm of the forage plant. The experimental design was completely randomized with three treatments (arboreal arrangements) and six replicates (paddocks) in the case of height and mass variables of the massaigrass and 5 repetitions (animals) of digestibility variables, intake and emission of methane (CH4). The pastures were evaluated in a year (water and dry seasons). The analysis of orthogonal contrasts was held (1st and 2nd degree) for grazing cycles and Tukey test for arboreal spacings (α = 5%). There was a significant difference (p <0.05) between treatments for sward height, ratio of dry matter forage: dead, dry herbage mass of pre and post grazing in the three cycles, the E6 treatment which presented the lower (p <0.05) values than the other treatments. There was a significant interaction (p <0.05) between grazing cycles and arboreal spacings for the average apparent digestibility of dry matter (DDM). The average DDM July cycle were greater (p <0.05) than those of March cycle. In cycle July average DDM varied between arboreal spacings being larger TL treatment (p <0.05) than the E6 treatment. There was a significant interaction (p <0.05) between grazing cycles and arboreal spacings for the average forage and energy intake. The dry matter intake (DMI) was higher in July grazing cycle. There was a significant difference (p <0.05) between the arboreal spacings only in average DMI, gross energy intake (GEI) and digestible energy intake (DEI) of July grazing cycle, where treatment TL showed higher (p <0.05) averages for the E6 processing. There was a significant interaction (p <0.05) between cycles of grazing and arboreal spacings in average CH4 emission by animals per day and per year (CH4day and CH4year). In the grazing cycle of July, the average CH4day and CH4year were higher (p <0.05) compared with the averages for March. The CH4 emission variables per unit of intake showed significant differences only for grazing cycle, where July showed lower (p <0.05) emission and CH4 per kg of dry matter consumed by gross energy consumption and digestible energy consumed when compared to emissions of March grazing cycle.