Thesis (MSc. (Animal breeding and genetics )) --University of Limpopo, 2006 / The objective of this study was to estimate genetic parameters for weekly body weight of feed intake of individually fed beef bulls at centralized testing stations in South Africa using random regression models (RRM). The model for cumulative feed intake included the fixed linear regression on third order orthogonal Legendre polynomials of the actual days on test (7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77 and 84 day) for starting age group and contemporary group effects. Random regressions on third order orthogonal Legendre polynomials were included for the additive genetic effect of the animal and the additional random effect of weaning-herd-year (WHY) and on fourth order for the additional random permanent environmental effect of the animal. The model for body weights included the fixed linear regression on fourth order orthogonal Legendre polynomials of the actual days on test for starting age group and contemporary group effects. Random regressions on fourth order orthogonal Legendre polynomials were included for additive genetic effects and additional uncorrelated random effects of the WHY and the permanent environment. The residual effects for both traits were assumed to be independently distributed with heterogeneous variance for each measurement period. Variance ratios for additive genetic, permanent environment and WHY for cumulative feed intake at different days on test ranged from 0.07 to 0.10, 0.53 to 0.77 and 0.14 to 0.37, respectively. Variance ratios for additive genetic, permanent environment and WHY for weekly body weights at different test days ranged from 0.26 to 0.29, 0.37 to 0.43 and 0.26 to 0.34, respectively. Estimates of genetic correlation among the same trait (body weight or feed intake) measured at different test days were generally high (>0.80) for any give test pair. The WHY had a significant contribution in variation of performance of bulls on test, despite the 28-day adjustment period. RRM provided the opportunity to study changes in genetic variability within the studied traits over time. Random Regression Models could be used in the National Genetic Evaluation of beef bulls at central performance testing stations in South Africa.

In the present study, haplogroup composition of five native Turkish sheep breeds, (Karayaka, Akkaraman, G&ouml / k&ccedil / eada, Dagli&ccedil / , Morkaraman) and two sheep breeds from neighboring countries (Herik from Iran, samples from Azerbaijan) were determined by single strand length polymorphism (SSCP) analysis of mitochondrial DNA (mtDNA) NADH dehydrogenase subunit 4 (ND4) region and restriction fragment length polymorphism (RFLP) analysis of mtDNA control (CR) region. Results of the SSCP and RFLP approaches were found to be 96,82% consistent. Most of the 3,18% inconsistency was due to unidentified band patterns of 9 individuals. SSCP method could identify haplogroups A, B and C, but not D and E. Similarly RFLP method could identify haplogroup A, B and possibly D, but not E and C. Data of the present study were compared with those of the previous studies to test the robustness of results under different samplings and were found to be homogenous with a previous study with similar sampling strategy. Neighbor joining tree, principal component analysis (PCA), Delaunay network analysis and analysis of molecular variance (AMOVA) were employed to analyze the haplogroup frequencies and breeds were separated in four groups according to the genetic barriers between breeds from different geographical locations. Strongest differentiation was present between two groups which were eastern breeds (Morkaraman, Herik-Iran and Azerbaijan) and western breeds (G&ouml / k&ccedil / eada, Akkaraman, Karayaka and Dagli&ccedil / ). Additionally, Azerbaijan was proposed as the entrance point of the haplogroup A and the Iran was proposed as the entrance point of haplogroup C to Anatolia with the Spearman rank correlation test.

In the first part of the present study, samples of 13 native Turkish sheep breeds (n=628) were examined, individually and comparatively, with respect to their 19 microsatellite loci to characterize them by employing various statistical analyses. Low FST values, high mean number of alleles and allelic richness as well as results of Factorial Correspondence Analysis and Structure analyses showed the degree of admixture between native sheep breeds of Turkey, IVE and SAK were observed as the most distincts of the breeds and possible introgressions were detected in other breeds. The 2- BAD, a software to examine the admixtures, was employed to estimate the time of the admixtures and the MSVAR software was employed to detect past demographic histories. In the second part, evaluations based on their genetic characteristics were made in relation to their prioritization in conservation studies. By employing four different approaches, it has been concluded that IVE, SAK, KRY, KIV, HEM and breed from Central Anatolia should be included in a conservation program for the preservation of optimum genetic diversity. In the last part of the thesis breeds were also characterized with respect to their relative risk of extinctions and their merits, which were used to estimate the utilities of the breeds. Non-genetic factors, collected based on the existing literature and surveys throughthe questionnaires filled by the field specialists, were incorporated into genetic factors to estimate the utilities of the breeds under different scenarios. In this approach, it is concluded that NOR, AKK, SAK, IVE and HEM should be included in the conserved set of breeds. By the present study, it is believed that specific genetic features of the native Turkish sheep breeds were documented, effects of sampling on the population genetic studies was discussed, the need for a reliable data (genetic and nongenetic, for characterizing the risks and merits of the breeds) for the prioritization of the breeds in the long term sustainable conservation ofthem was emphasized.

Feedlot performance, carcass merit and chemical composition were compared using Waguli , Brangus, Hereford x Tuli and Wagyu x Crossbred Gene Combination (CGC) breeds. Steers were penned in the following manner: 6 Waguli steers, 6 Hereford x Tuli, 6 Wagyu x CGC and 8 Brangus. There was a significant difference (P<0.05) between Brangus and Waguli for ADGs. F:G was lower (P<0.05) for Hereford x Tuli compared to the other crossbreeds. A heavier final weight was observed (P<0.05) for the Wagyu x CGC than all other crossbreds. There was a significant difference (P<0.05) for REA between Wagyu x CGC and Hereford x Tuli and Waguli. Wagyu x CGC had higher shear force values (SFV) (P<0.05) than all other crossbreeds. Cost of gain was lower (P<0.05) for Hereford x Tuli compared the other breeds. Hereford x Tuli also had less protein (P<0.05) than to the other breeds.A second study was conducted comparing limit feeding (LF) vs. full feeding (FF) strategies. 23 steers and 27 heifers were penned by sex and were randomly assigned a treatment; 4 pens received the LF treatment and 4 were FF. ADG was lower (P<0.05) for LF and FF heifers compared to both LF and FF steers. Dressing percentage was lower (P<0.05) for LF steers compared to LF and FF Heifers. LF heifers YG was higher (P<0.05) compared to FF steers. Quality grades were higher (P<0.05) for LF and FF heifers compared to LF and FF steers. REA /cwt was significantly higher (P<0.05) for FF heifers compared to LF and FF steers. SFV were11lower (P<0.05) for FF heifers compared to LF and FF steers. A significant difference (P<0.05) in cost of gain was noted between LF steers and the rest, also between LF heifers and FF steers. Primal cut price/cwt was significantly lower (P<0.05) for LF heifers compared to FF steers. Lipid percentage was higher (P<0.05) LF heifers compared to FF steers. Moisture percentage was lower (P<0.05) for LF heifer compared to the other groups.

Indigenous chicken production receives little institutional support and resources because of lack of information on the socioeconomic importance, morphometric characteristic and meat quality of indigenous chickens. A cross sectional survey was conducted to highlight the major constraints to production. A structured questionnaire was administered to 126 households selected from communities of Mnambiti-Ladysmith and Impendle local municipalities of KwaZulu-Natal Province of South Africa. The mean flock size per household was 20 and 17 for Mnambiti-Ladysmith and Impendle, respectively. The cock to hen ratio was 1:2:5. The chickens were mostly kept for meat and income ranked 1 and 2 respectively. Generally, adult females made the majority of decisions on chicken management and marketing (61%), with youths playing a minor role. Scavenging was the major feeding system, seasonally supplemented with cereal grain. The majority of the farmers (87%) provided birds with drinking water. Mortality of chickens was prevalent (46%) in both seasons. In experiment 2, the objective of the study was to compare morphometric characteristics of Black Australorp, Potchefstroom Koekoek, Venda and Ovambo chickens. A flock of 200 indigenous chickens, 50 each of Black Australorp, Potchefstroom Koekoek, Venda and Ovambo breeds were reared under semi-intensive system for 22 weeks. The chickens were slaughtered at 22 weeks of age by manual neck cut, bled for 2 minutes and de-feathered. Body weights, organ weights and linear body measure were estimated using flexible tape prior to slaughter. The body weight for the Black Australorp were higher (P<0.05) than the other breeds. There was no significant difference between the lung, heart kidney and spleen weights among breeds. Linear regression revealed that measurements of linear body parts can be used to predict weight of the birds. The objective of Experiment 3 was to compare consumer acceptability of meat from chickens that are indigenous to South Africa compared to Black Australorp and the broiler. A flock of 200 unsexed freely ranging indigenous chickens of Potchefstroom Koekoek, Venda, Black Australorp and Ovambo breeds were reared under an improved semi-intensive system for 22 weeks. The acceptability of cooked meat samples from each breed was rated on a 9 point Hedonic scale by 69 consumer pannellists drawn from the University of KwaZulu-Natal, Cedara College of Agriculture and the Depart of Agriculture. Age of consumer had no effect on all the sensory attributes of the meat evaluated (P> 0.05). Chicken breed had a significant effect on taste and overall acceptability (P< 0.05) with the Venda, Broiler and Black Australorp, but it had no significant difference on colour, texture and aroma acceptability. Gender of the consumer had a significant effect (p<0.01) on taste, colour and texture acceptability of the meat, but no significant effect on aroma and overall acceptability. Female respondents gave lower scores for taste than did the males (P< 0.01). There was no interaction between gender of consumer and chicken breed on meat texture. Crossbreeding the indigenous chickens with improved breeds such as the Black Australorp is one avenue through which sensory characteristics of the indigenous chickens may be improved. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 4 uppsatser.

Made available in DSpace on 2014-06-11T19:26:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-04-29Bitstream added on 2014-06-13T18:54:01Z : No. of bitstreams: 1 santos_dja_me_jabo.pdf: 949817 bytes, checksum: 99fe4837bb2182ae9951f9ef2a71f250 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Parâmetros genéticos para a produção de leite no dia do controle (PLDC) de primeiras lactações de vacas da raça Guzerá foram estimados utilizando modelo multicaracterísticas de dimensão finita (TMDO) e modelos de regressão aleatória (MRA). A produção acumulada em 305 dias (P305), duração da lactação (DL) e persistência da lactação (PS) também foram analisadas. Para o TMDO, foram analisadas as PLDC juntamente com a P305 e a DL, considerando como aleatórios, o efeito genético aditivo e o residual e, como fixo, o grupo de contemporâneos e a covariável idade da vaca ao parto. Para os MRA, foram considerados como aleatório, o efeito genético aditivo, de ambiente permanente e residual e como efeito fixo, o grupo de contemporâneos, os efeitos linear e quadrático da covariável idade ao parto e a curva média da população. Para os MRA foram consideradas as funções de ajuste de Wilmink (WL), Ali & Schaeffer (AS), uma combinação entre a função de Wilmink com polinômios ortogonais de Legendre (LM), polinômios ortogonais de Legendre (LEG) e funções B-spline (BS). Os efeitos aleatórios genético aditivo e de ambiente permanente foram modelados por meio destas funções, bem como a curva média da população, com a exceção dos modelos ajustados por funções BS que tiveram a curva média ajustada por polinômio de Legendre ou pela função de Ali & Schaeffer. O resíduo foi ajustado considerando variância homogênea ou em classes heterogêneas de variância residual. O modelo empregando funções BS cúbica com número de coeficientes de regressão aleatória igual cinco tanto para efeito genético aditivo como de ambiente permanente com a curva média modelada pela função de Ali & Schaeffer e resíduo ajustado por seis classes variância residual foi o mais adequado. Entretanto, os melhores MRA para cada função de ajuste, não apresentaram diferenças para... / Genetic parameters for milk production in the test day model (PLDC) for Guzerat dams’ first lactations were estimated by multitrait finite model (TMDO) and random regression models (MRA). The cumulative production at 305 days (P305), lactation length (DL) and lactation persistency (PS) were also analyzed. For TMDO, the PLDC were analyzed together with P305 and DL, considering the additive genetic effect and residual effect as random effects , the contemporary group as a fixed effect, and the age of dam at calving as a covariate. For MRA, additive genetic effect, permanent environmental effect and residual effect were considered as random effects and the contemporary group, the linear and quadratic covariate of age at calving and the average curve of the population as fixed effects. Also for the MRA, the Wilmink (WL) and the Ali & Schaeffer (AS) adjustment functions, a combination of the Wilmink function with Legendre orthogonal polynomials (LM), Legendre orthogonal polynomials (LEG) and B-spline functions (BS) were considered. The random additive genetic and permanent environmental effects were modeled by means of these functions, as well as the population average curve , with the exception of the adjusted models by the BS functions that had the average curve adjusted by the Legendre polynomial or by the Ali & Schaeffer function. The residual error was adjusted considering homogeneous variance or heterogeneous classes of residual variance. The model using cubic BS functions with random regression coefficient numbers equal to five for additive genetic effect as well as for permanent environmental with average curve modeled by the Ali & Schaeffer function and residual error adjusted for six classes of residual variance was the more appropriate. However, the best MRA for each adjustment function presented no differences in the estimates of genetic parameters and for order correlation ... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:33:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-06-01Bitstream added on 2014-06-13T20:27:49Z : No. of bitstreams: 1 gandra_ers_dr_botfmvz.pdf: 231357 bytes, checksum: 92d3c168799da775daa0fbd8f6879a6d (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / Objetivou-se estimar o melhor nível de lisina digestível e sua relação com a energia metabolizável em dietas de suínos dos 50 aos 70 kg de peso vivo. Para tanto, foram realizados dois ensaios de desempenho, um com 72 machos castrados e outro com 72 fêmeas, com pesos médios iniciais de 49,75±0,41 kg e de 46,05±0,38 kg, respectivamente. O delineamento experimental usado nestes experimentos foi em blocos ao acaso com seis tratamentos, seis repetições e dois animais por unidade experimental (baia). No final dos experimentos mediu-se área de olho de lombo e espessura de toucinho na 10ª costela, por meio de ultrassonografia, em todos os animais. Também colheu-se sangue para leucograma de quatro animais dentro de cada tratamento, de forma aleatória, totalizando 24 machos castrados e 24 fêmeas, considerando delineamento inteiramente ao acaso, com quatro repetições por sexo e o animal era a unidade experimental. Os tratamentos foram 7,00; 8,00; 9,00; 10,00; 11,00 e 12,00 g de lisina digestível/kg de ração que continham 14,25 MJ de energia metabolizável/kg de ração e, em média, 160,92 g de proteína bruta/kg de ração. Realizou-se também um ensaio de digestibilidade e metabolismo, com 12 machos castrados e 12 fêmeas, em que foram avaliadas quatro dietas (7,00; 9,00; 10,00 e 12,00 g de lisina digestível/kg de ração), com três repetições e um animal por unidade experimental (gaiola). No ensaio de desempenho das fêmeas observou-se aumento linear na conversão alimentar, no consumo de proteína bruta (g/dia) e na eficiência de proteína bruta no período experimental de 0 a 16 dias. No período experimental de 0 a 32 dias observou-se aumento linear no consumo de proteína bruta (g/dia) e na eficiência de proteína bruta, bem como efeito quadrático no ganho de peso relativo (%) e na... / This study aimed to estimate the optimum level of lysine and its relation to metabolizable energy in diets for pigs from 70 to 100 kg live weight. For this, were two performance tests, one with 72 barrows and other with 72 females, with average initial weight 76.86 ± 0.90 kg and 76.92 ± 0.96 kg, respectively, the experimental design was a randomized block with six treatments and six replicates of two animals per experimental unit (pen). At the end the experiments was measured loin eye area and backfat thickness at the 10th rib by means of ultrasound in all animals. Also picked up blood WBC to four animals in each treatment, totaling 24 males castrated and 24 female maturation, being considered the completely randomized design, with four replications for sex and the animal was the experimental unit. After fasting for 12 hours, were chosen at random, 24 castrated males and 24 females (four per treatment), which were sent to slaughter in the abattoir for commercial Ratings and carcass boning. The treatments were 7.00, 8.00, 9.00, 10.00, 11.00 and 12.00 g of lysine per kg diet containing 14.25 MJ of ME per kg feed and on average 155.20 g crude protein per kg feed. In assay digestibility and metabolism were used 12 castrated males and 12 females, with evaluation of four diets (7.00, 8.00, 11.00 and 12.00 g of lysine / kg) with three replicates and one animal per experimental unit (cage). In the performance test females observed linear... (Complete abstract click electronic access below)

Made available in DSpace on 2016-12-08T16:24:07Z (GMT). No. of bitstreams: 1 PGCA09MA053.pdf: 843427 bytes, checksum: 7ebe808027ce4ad608229f7421147b81 (MD5) Previous issue date: 2009-10-19 / The Brazilian dairy uses the Holstein breed as the main specialized breed in its herds, as the crossbreeding is normally used to solve problems of animal adaptability in relation to regional differences, especially in the tropic areas. Changes in national legislation on the composition and quality of the marketed milk as well as research efforts in countries with developed dairy farming with the use of crossbreeding between specialized dairy breeds which has made the practice of crossbreeding between Holstein and Jersey breeds more popular in subtropical climate regions in southern Brazil, and has motivated this paper. The objective of this study was to compare productive, reproductive, and growth traids of crossbred Holstein x Jersey in relation to the Holstein straigthbred. Evaluations have been carried out on 4 dairy farms in the states of Santa Catarina and Parana, which present in their breeding stock animals which belong to the Holstein breed and Holstein x Jersey crossbreds. The growth of female calves and heifers was evaluated based on measurements performed in females up to 24 months of age, during the period from February 2008 to January 2009. Data such as height, heart girth and body weight estimated from heart girth of Holstein straigthbred and Holstein x Jersey crossbreds with varying degrees of blood were subjected to analysis of variance. Curves of body weight, height at withers and heart girth were generated for the different genetic groups. It has been observed superiority in the development of Holstein cows in relation to crossbreed. However; there is no difference between ½ Holstein x Jersey crossbred animals and a higher proportion of Holstein genes (3/4 and 5/8). Production data and reproduction characteristics were obtained based on the files of the participating dairy herds. The data were subjected to analysis of variance. Half Holstein x Jersey cows had lower milk production up to 305 days of lactation compared to Holstein straigthbred cows (P = 0.04 - 8978.3 vs. 9527.7 kilograms), which represents 94% of the milk produced by straigthbred cows. However, a higher fat yield in 305 days (P = 0.09 - 240.6 vs. 227.3 kilograms), which represents an advantage of 6% compared with Holstein cows. It has not been observed the effect of genetic group for protein production in 305 days of lactation (P = 0.82). Crossbred cows presented higher levels of fat and protein milk content (P <0.0001). No difference between half Holstein x Jersey cows and straigthbred Holstein was observed for the reproductive efficiency, evaluated as calving interval (P = 0.51). We are concluded that Holstein x Jersey crossbred calves and heifers show lower growth than the straigthbred Holstein, so that a weight of 310 to 320 kg can be indicated for the first insemination. In a Holstein x Jersey crossbreeding program, it is necessary to consider that, in relation to straigthbred Holstein cows, increased fat yield and milks fat and protein percentage can be expected, but with reduction of milk yield / A pecuária leiteira brasileira utiliza a raça Holandesa como principal raça especializada em seus rebanhos, sendo o cruzamento normalmente utilizado para resolver problemas de adaptabilidade dos animais às diferenças regionais, especialmente nas regiões tropicais. Modificações na legislação nacional referente à composição e qualidade do leite comercializado, assim como esforços de pesquisa em países de pecuária leiteira desenvolvida com a utilização de cruzamento entre raças leiteiras especializadas, têm tornado a prática de cruzamento entre as raças Holandesa e Jersey mais populares nas regiões de clima subtropical, do Sul do Brasil e motivaram o presente trabalho. O objetivo deste trabalho foi comparar características produtivas, reprodutivas e de desenvolvimento de animais mestiços Holandês x Jersey em relação ao Holandês. As avaliações foram feitas em 4 propriedades nos estados de Santa Catarina e Paraná, que apresentam em seus plantéis animais da raça Holandesa e mestiços Holandês x Jersey. O desenvolvimento de bezerras e novilhas foi avaliado a partir de mensurações realizadas em fêmeas com até 24 meses de idade, no período de fevereiro de 2008 a janeiro de 2009. Dados de altura, perímetro torácico e peso vivo estimado a partir do perímetro torácico de animais puros da raça Holandesa e mestiços Holandês x Jersey, com diversos grupamentos genéticos, foram submetidos à análise de variância. Curvas de peso vivo, altura à cernelha e perímetro torácico foram geradas para os diferentes grupamentos genéticos. Observou-se superioridade no desenvolvimento dos animais da raça Holandesa em relação aos mestiços, porém, sem diferença entre os animais ½ Holandês x Jersey e os mestiços com maior proporção de genes da raça Holandesa (3/4 e 5/8 Holandês). Dados de características produtivas e reprodutivas foram obtidos a partir dos arquivos zootécnicos dos rebanhos participantes. Os dados foram submetidos à análise de variância. Vacas ½ Holandês x Jersey apresentaram menor produção de leite em até 305 dias de lactação em relação às vacas puras Holandês (P = 0,04 - 8978,3 vs. 9527,7 kg), o que corresponde a 94% do volume de leite produzido pelas vacas puras. Entretanto, apresentaram maior produção de gordura em até 305 dias (P = 0,09 - 240.6 vs. 227,3kg), o que corresponde a uma superioridade de 6% em relação às vacas da raça Holandesa. Não foi observado efeito do grupo genético para produção de proteína em até 305 dias de lactação (P = 0,82). Vacas mestiças apresentaram maiores teores de gordura e proteína no leite (P <0,0001). Não foi observada diferença entre vacas ½ Holandês x Jersey e vacas puras Holandês quanto à eficiência reprodutiva, 7 avaliada através do intervalo de partos (P = 0,51). Conclui-se que bezerras e novilhas mestiças Holandês x Jersey apresentam crescimento menos acelerado em relação às puras Holandês, podendo-se indicar a inseminação de novilhas mestiças Holandês x Jersey com 50% ou mais de genes da raça Holandesa a partir de 310 a 320 kg de peso vivo. Ao optar por um programa de cruzamento entre as raças Holandesa e Jersey, deve-se considerar que, em relação à raça Holandesa, teores de gordura e proteína mais elevados podem ser esperados, assim como um pequeno incremento na produção de gordura, porém, com pequena redução na produção de leite por vaca