Devido às mudanças climáticas, a adaptação das raças de touro às condições ambientais torna-se um aspecto importante para a expressão do seu potencial genético. O objetivo deste trabalho foi avaliar a performance reprodutiva de touros da raça Braford, através do Índice de Temperatura e Umidade (ITU) e as suas relações com as características seminais de touros mantidos em diferentes climas do Brasil. Foram utilizados setenta e seis touros da raça Braford (5/8 Hereford x 3/8 Nelore), de seis propriedades rurais localizadas nos municípios de Rondonópolis (MT), Porto Nacional (TO) e Rio Verde (GO); Uruguaiana (RS), São Gabriel (RS) e Lages (SC). A avaliação seminal foi realizada 4 vezes em cada local. Os dados climáticos de temperatura e umidade foram coletados a cada hora de estações automáticas do Instituto Nacional de Meteorologia de cada localidade. O ITU foi analisado no período de 30, 18 (espermiogênese) e 12 dias (trânsito epididimário) antes da coleta seminal. Os maiores ITU foram observados no verão na localidade de Uruguaiana (83,69) e durante a estação chuvosa em Rondonópolis (80,15) Os menores valores de ITU foram observados durante o outono e inverno de Lages (51,66 e 50,03) e na estação chuvosa de Rio Verde (72,05). Na qualidade seminal, turbilhonamento (T), motilidade (M) e vigor (V) são menores no inverno de São Gabriel (2,87 ± 0,61; 60,60 ± 10,80 e 2,87 ± 0,51). Os defeitos espermáticos totais foram superiores em Uruguaiana (21,42 ± 1,26). Em Rio Verde, T, M e V foram menores (2,69 ± 0,17; 63,79 ± 4,01 e 2,69 ± 0,17) e maiores percentuais de defeitos maiores e menores (29,01 ± 3,24 e 16,02 ± 1,80). A motilidade mostrou correlação negativa com o ITU de 30 e 18 dias (-0,121 e -0,163; P<0,01), equanto que os defeitos totais estão correlacionados positivamente com todos os períodos de ITU (0,234; 0,207 e 0,198; P<0,01). Apesar dos altos índices de ITU, a qualidade seminal não mudou significamente para reprovar algum touro ao exame andrológico durante todas as estações, mostrando que os touros Braford são capazes de trabalhar a campo sob diferentes climas quente, demonstrado pelo ITU. / Due to climate change, the adaptation of bull breeds to environmental conditions becomes an important aspect for the expression of genetic potential. The objective of this study was to evaluate the reproductive performance of Braford bulls, through the Temperature and Humidity Index (THI) and its relationships with the seminal characteristics of bulls sustained in different climates of Brazil. Seventy-six Braford bulls (5/8 Hereford x 3/8 Nellore) were used, of six farms located in the cities of Rondonópolis (MT), Porto Nacional (TO) and Rio Verde (GO); Uruguaiana (RS), São Gabriel (RS) and Lages (SC). The seminal evaluation was performed four times at each location. Temperature and air humidity data were collected every hour from the automatic weather station at the National Institute of Meteorology. The THI was analyzed in the period of 30, 18 (spermiogenesis) and 12 days (epididymal transit) before seminal collection. The highest THI were observed in the summer of Uruguaiana (83.69) and in the rainy season of Rondonópolis (80.15) The lowest values of THI were observed in the autumn and winter of Lages (51.66 and 50.03), and in the rainy season of Rio Verde (72.05). In sperm quality, mass motion (MM), motility (M) and vigor (V) are lower in the winter of São Gabriel (2.87 ± 0.61; 60.60 ± 10.80 and 2.87 ± 0.51). The total defects were higher in Uruguaiana (21.42 ± 1.26). In Rio Verde, MM, M and V were lower (2.69 ± 0.17; 63.79 ± 4.01 and 2.69 ± 0.17) and higher percentages of major and minor defects (29.01 ± 3.24 and 16.02 ± 1.80). Motility showed a negative correlation with THI of 30 and 18 days (-0.121 e -0.163; P<0.01), while the total defects are positively correlated with all periods of THI (0.234; 0.207 and 0.198; P<0.01). Despite the high THI indexes, the sperm quality has not changed significantly to reject a bull during BBSE exam during all seasons, showing that Braford bulls are able of field service under different hot climates, as demonstrated by the THI.

Thirty-six half-sibling Angus bulls were assigned one of three diets: 1) 60% corn-based (CON; S = 0.18%; n = 12); 2) 60% DDGS replacing corn (60DDGS; S = 0.55% DM; n = 12); 3) CON diet + equivalent sulfur of 60DDGS added as calcium sulfate (SULF; S = 0.54%; n = 12) to evaluate the effects of feeding diets containing DDGS or calcium sulfate on performance and semen characteristics. Bulls began the study at 9 months of age and gained 1.6 kg/day for 112 days. Treatment by day interactions (P < 0.05) were observed for glutathione peroxidase and trace mineral concentrations in seminal plasma. Effects of treatment (P < 0.05) were observed for semen kinematics and triiodothyronine in serum. Alterations observed when feeding 60% DDGS to developing bulls occurred in a manner that is not dependent on dietary sulfur; therefore, observed changes could be related to other components within DDGS.

In this study, 14 typical South African feedlot bulls received no beta-adrenergic agonist for the last 30 days of the finishing period (C), 14 received 120 mg R-salbutamol per animal per day for the last 30 days of the finishing period (S30), 13 received 120 mg Rsalbutamol per animal per day for the last 40 days of the finishing period (S40) and the last group of 13 bulls received 60 mg zilpaterol hydrochloride per animal per day for the last 30 days of the finishing period (Zh). All animals were slaughtered after a 3-day withdrawal period. Parameters included weight gain, feed intake, feed conversion rate, warm and cold carcass mass, dressing %, subcutaneous fat thickness, hide yield %, internal carcass fat distribution, % bone, % fat and % muscle of the prime rib-cut, carcass classification code, conformation, compactness, post-mortem carcass pH profiles, cooking loss, shear force, blood urea nitrogen, creatinine and residue levels of the beta-adrenergic agonists. No differences were observed between any of the four treatment groups concerning live feedlot performance. Bulls receiving the S30 and Zh treatments had lower internal carcass fat distribution compared to C bulls (P <0.05). Bulls receiving the S40 treatment had a lower % fat in the prime rib-cut compared to Zh bulls (P <0.05). Carcasses from S30 bulls had higher pH values 24 hours post mortem compared to carcasses from Zh bulls (P <0.01). Meat samples from Zh bulls had higher shear force, which indicates less tender meat, compared to samples from S40 bulls (P <0.05). Change in serum creatinine levels increased only in Zh treated bulls from the start to the end of treatment and may reflect a higher protein turnover in Zh bulls. The results of this study indicate that R-salbutamol has a more pronounced effect on fat metabolism in feedlot bulls compared to zilpaterol hydrochloride, while zilpaterol hydrochloride has a more pronounced effect on protein metabolism. The residue levels in samples of the liver, kidney, muscle and feaces from zilpaterol hydrochloride and R-salbutamol treated bulls were well below acceptable limits. / Dissertation MSc(Agric)--University of Pretoria, 2014 / gm2015 / Animal and Wildlife Sciences / MSc(Agric) / Unrestricted

Compared to natural selection, the use of artificial insemination (AI) and other reproductive technologies rapidly increase the rate of genetic change in any population. In order to achieve success with AI, the semen used to inseminate cows must be of the highest possible quality. When semen is frozen, generally only about 50% of the spermatozoa survive the cryopreservation process. Thus, any factors possibly affecting the survival of spermatozoa through the numerous freezing-thawing steps should be studied, in order to identify the optimal conditions for the survival of spermatozoa. The discovery of protective agents within egg yolk and glycerol was a major milestone in sperm cryopreservation. These agents protect bovine spermatozoa during cooling and freezing procedures and result in increased survival rates. Cryopreservation of spermatozoa has become the most common technique for the preservation of male fertility of genetically superior sires even after their death. Using cryopreserved sperm to artificially inseminate females has become standard practice in commercial dairy cattle herds and the application of this reproductive management tool is also expanding to beef herds worldwide. The use of glycerol as a cryoprotectant for bovine spermatozoa is credited as the reason for the success in bovine semen cryopreservation. The purpose of this research was to quantify the effects of different cooling periods, as well as different glycerol equilibration periods on the post-thaw motility percentages and recovery fractions of semen collected from Boran and Nguni bulls. The research was subdivided into two experiments. In each experiment different cooling and glycerol equilibration times were researched. The first experiment involved shorter cooling times (30, 60, 120 and 240 minutes) with each cooling time followed by several longer equilibration times (4, 5, 6, 7 and 8 h). In the second experiment the cooling and equilibration times from the first experiment were reversed. This resulted in longer cooling times (4, 5, 6, 7 and 8 h) with each cooling time having shorter glycerol equilibration times (30, 60, 120 and 240 minutes). An egg yolk-Tris two-step extender was used in both the experiments. The general trend for the glycerol equilibration periods studied in Experiment 1 was that the resulting overall average post-thaw motility percentage and average recovery fraction increased with longer periods. There was a breed difference when comparing the average post-thaw motility percentages after 4, 5, 6 and 8 h (p<0.05), while the average post-thaw motility percentages also tended to differ after 7 h of equilibration. The general trend observed for equilibration periods used in Experiment 2 was that the average post-thaw motility percentage increased as glycerol equilibration period increased up to 120 minutes, but after 240 minutes of glycerol equilibration, there was a slight decline. The differences in average post-thaw motility percentage after the respective glycerol equilibration periods were not statistically significant. The results of each experiment were used to create a matrix that can be used in practice. The matrix using results from Experiment 1 demonstrated that a cooling period glycerol equilibration period combination of 240 minutes and 7 h resulted in the highest (not significantly different from most other combinations) average post-thaw motility rates. The matrix formed from the results of Experiment 2 demonstrated that an 8 h cooling period combined with a 60 minute glycerol equilibration period yielded the highest (not significantly different from most other combinations), average post-thaw motility percentage. / Dissertation (MSc(Agric))--University of Pretoria, 2010. / Animal and Wildlife Sciences / unrestricted

The bull was a potent symbol of power, strength, and, to a lesser degree, fertility to the peoples of the ancient Near East from the twelfth century until 330 BCE. This symbolism was manifested in several iconographic motifs. These motifs reveal the bull as a manifestation of divine characteristics and as an expression of the power of man, and particularly the authority of the king. The use of these iconographic motifs was not consistent across the entire area of the ancient Near East; some differed in appearance and use in the different areas of the region, and many changed over time even in the same area. In all areas and during all periods the basic core symbolism stayed the same, and the bull was always held in a special respect. / Old Testament and Ancient Near Eastern Studies / M.A. (Ancient Near Eastern Studies)

The bull was a potent symbol of power, strength, and, to a lesser degree, fertility to the peoples of the ancient Near East from the twelfth century until 330 BCE. This symbolism was manifested in several iconographic motifs. These motifs reveal the bull as a manifestation of divine characteristics and as an expression of the power of man, and particularly the authority of the king. The use of these iconographic motifs was not consistent across the entire area of the ancient Near East; some differed in appearance and use in the different areas of the region, and many changed over time even in the same area. In all areas and during all periods the basic core symbolism stayed the same, and the bull was always held in a special respect. / Old Testament and Ancient Near Eastern Studies / M.A. (Ancient Near Eastern Studies)

Made available in DSpace on 2016-04-28T20:18:32Z (GMT). No. of bitstreams: 1 2009 - Alexandre Galvao.pdf: 298975 bytes, checksum: 9d22ecc92482b98f474bee4de0969bdd (MD5) Previous issue date: 2009-02-19 / Dermatobia hominis affects bovines, causing serious economic damages and of productivity for the beef cattle. The occurrence of dermatobiosis and alteration in the fertility of bulls come being currently studied with intention to evaluate its influence on the parameters of the spermatic quality. The objective of this study was to evaluate the clinical analysis of the masculine reproductive system, the testicular perimeter, the physical characteristics as motility, turbidity, intensity and spermatic concentration, and morphology of the semen. For in such a way, 18 bulls of the commercial Nelore race had been used, with age of 36 months, variation of corporal score of 6.0 to 6.5, after pre selection, following the standard of the Manual of the CBRA. The bulls had been placed in two groups: G1 (nine infested with D. hominis larvae on the scrotal skin) and G2 (nine bulls as controls), and they were submitted to the andrologic examinations in the days D24, D48, D63 and D74 and evaluated the testicular and seminal characteristics. The gotten average values of these parameters had been analyzed by the variance test, and results had indicated that it did not have significant difference (p< 0.005). These results indicate that the experimental infestation of D. hominis in the escrotal skin did not influence the spermatic quality of bulls of the Nelore race. / Dermatobia hominis afeta os bovinos, causando graves preju?zos econ?micos e de produtividade para a pecu?ria de corte. A ocorr?ncia da dermatobiose e altera??o na fertilidade de touros v?m sendo estudadas atualmente com intuito de avaliar a sua influ?ncia sobre os par?metros da qualidade esperm?tica. O objetivo deste estudo foi avaliar clinicamente o aparelho reprodutor masculino, o per?metro testicular, as caracter?sticas f?sicas (motilidade, turbilhonamento, vigor e concentra??o esperm?tica) e morfol?gicas do ejaculado. Foram utilizados 18 touros da ra?a Nelore comercial, com idade de 36 meses, com varia??o de escore corporal de 6,0 a 6,5, ap?s a pr?-sele??o seguindo o padr?o do Manual do CBRA. Os touros foram alocados em dois grupos: G1 (nove infestados com larvas de D. hominis na bolsa escrotal) e Grupo 2 ( nove touros, controle), e submetidos aos exames androl?gicos nos dias D24, D48, D63 e D74 e avaliadas as caracter?sticas testiculares e as seminais. Os valores m?dios obtidos destes par?metros foram analisados pelo teste de vari?ncia, e os resultados indicaram que n?o houve diferen?a significativa (P<0.05). Estes resultados indicam que a infesta??o experimental de D. hominis na bolsa escrotal n?o influenciou a qualidade esperm?tica de touros Nelore.

Thesis (M.Sc.) (Agriculture) --University of Limpopo, 2007 / The objectives of this study were to evaluate the effect of pre-weaning selection on estimates of genetic parameters for post-weaning average daily gain in Phases C (ADG-C) and D (ADG-D) and to estimate genetic relationships between average daily gain in the two phases. Performance records of the South African Angus cattle breed was used in the analysis. (Co)variance components and genetic parameters for weaning (WWT), AGD-C and ADG-D were estimated by REML procedures fitting three different models (Models 1, 2 and 3) that differed in how they integrated sequential selection in the analysis of post-weaning traits. Model 1 was a univariate model of WWT, ADG-C and ADG-D. Model 2 was a two trait model of WWT and either ADG-C or ADG-D. Model 3 was a three trait model of WWT, ADG-C and ADG-D. Estimates of heritability for ADG-C were 0.39±0.08, 0.42±0.06 and 0.44±0.01 from Model 1, 2 and 3 respectively. Corresponding estimates of heritability for ADG-D were 0.18±0.021, 0.19±0.021 and 0.21±0.02 respectively. An estimate of genetic correlation between ADG-C and ADG-D was 0.58± and it suggested that the two traits may not necessarily be under the same genetic control. Rank correlations for all bulls based on ADG-C estimated breeding values (EBV’s) were 0.92, 0.83 and 0.94 for Model 1 vs. Model 2, Model 1 vs. Model 3 and Model 2 vs. Model 3 respectively. Corresponding ADG-D EBV’s rank correlations were 0.88, 0.84 and 0.93. Rank correlations for top and bottom 1%, 5% and 10% were lower than those for all bulls in both ADG-C and ADG-D. Low rank correlations showed that the difference in magnitude of genetic parameters from different models was enough to alter bull rankings based on EBV’s of ADG-C and ADG-D. Hence it was concluded that inclusion of pre-weaning information in genetic analysis for post-weaning average daily gain is necessary to account for selection at weaning. / the THRIP (Technology and Human Resource for Industry Project) and NRF (National Research Foundation).

Cattle breeding is one of the part of traditional Czech agriculture. It is a vital part of economy consisting of two main branches - milk and beef production. Beef is one of the main products of cattle breeding sometimes provided by fattening of heifers, cows and bulls. Producing meat with the highest quality with low costs is the main goal of fattening the cattles. I have tested the influence of selected fators on the fattening capacity and carcass values of Czech Fleckvieh bulls in the control station as well as the economic requirements of the fattening period. I have compared the test period of 530 ? 10 days with period of 610 ? 10 days of fattening using the old and new technology of supplementation. Further fattening was provided by results of growing Charolais, Limousin and Czech Fleckvies x Simmental bulls. The results suggest that the increase of the period of fattening for 80 days had a positive effect on carcass yield (p < 0.001), assigning in the classification according to SEUROP and profitability of farming. The positiv relationships between breeding value of fathers and carcass yield of their sons was observed. Finally, the positive influence of new technology of fattening on the classification acording to SEUROP was shown.

Made available in DSpace on 2014-06-11T19:32:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-07-14Bitstream added on 2014-06-13T21:05:29Z : No. of bitstreams: 1 cucki_to_dr_botfmvz.pdf: 235516 bytes, checksum: 26d4062ad230e6aa7ed7e3709b2ed5c2 (MD5) / Universidade Estadual Paulista (UNESP) / O objetivo deste trabalho foi avaliar os efeitos da proporção de sangue zebuíno no desempenho animal em confinamento, mensuração do crescimento animal, bem como as características de carcaça ao abate de bovinos jovens. Foram utilizados 96 novilhos não castrados, sendo, 24 da raça Nelore (N), 24 three cross Angus x Nelore x Brahman (TBH), 24 da raça Brangus (BG) e 24 three cross Angus x Nelore x Pardo - Suíço (TPS). Maior peso ao abate foi apresentado pelo grupo TPS (<0,01), seguidos pelos grupos BG e TBH, assim como maior ganho de peso médio diário, não diferindo do grupo BG.O grupo N apresentou menor ganho de peso médio diário e pior conversão alimentar (<0,01), entretanto apresentaram o maior peso de carcaça quente, juntamente com os grupos TPS e TBH, mesmo não diferindo dos outros três grupos quanto ao rendimento de carcaça. / The objective of this study was to evaluate the efects of different proportions of Bos indicus genotype on the feedlot performance, animal growth and carcass traits. There were used 96 bull calves, being 24 Nelore (N), 24 Angus x Nelore x Brahman (TBH) threecrosses, 24 Brangus (BG) e 24 Angus x Nelore x Brown Suiss (TPS) threecrosses. The TPS cross showed higher slaugther weigth (<0.01) followed by the BG and TBH groups. The groups TPS and BG had higher average daily gain. The N group had lower average daily gain and worst feed conversion rate (<0.01). However, it had, with the TPS and TBH groups, higher hot carcass weigths. The carcass yield did not differ among the treatments.