Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 81-83). Also available via the Internet.

Thesis (MS)--Montana State University--Bozeman, 2009. / Typescript. Chairperson, Graduate Committee: James G. Berardinelli. Includes bibliographical references (leaves 53-61).

Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains v, 56 p. Includes abstract. Includes bibliographical references (p. 54-56).

No description available.

A total of 1926 A.I. sampled Holstein bulls born from 1984 to 1988 and with first proofs from Summer 1991 to Summer 1993 were used to determine the accuracy of predicting PTAT and DTD from different sources of pedigree information obtained before the bull had daughter information. Pedigree sources used were PA, PI, PTAT_SIRE, and PTAT_DAM. Simple linear regression was used to determine which pedigree source predicted PTAT or DTD with the highest accuracy (highest R²). R² was higher for PA than had the other pedigree sources. R²s for PA to predict initial PTAT and DTD with daughter information were .59 and .18 respectively. Higher weights and R²s for PTAT than DTD resulted from the part whole relationship between PA and PTAT. Accuracy of prediction varied depending on when a bull received his first proof. R² values for PA to predict initial PTAT ranged from .35 to .69, and increased as the time of the pedigree estimate approached the date of the initial proof. R² values for PA to predict initial DTD ranged from .16 to .21 and increased as the time of the pedigree estimate approached the date of the initial proof. The impact of the within herd variance correction which was implemented in the Summer 1993 summary was also evaluated. Correlations between PA, PI, PTAT_SIRE, and PTAT_DAM from the Winter 93 and Summer 93 evaluations were .98, .99, .99, and .96 respectively. Regression of the change in DTD estimated from previous PA minus actual DTD on PTAT_DAM S 93 - PTAT_DAM W 93 for bulls grouped by date of initial proof gave R²s from .00 to .06. It was concluded that the variance correction had little impact on the dam’s of bulls in this study. The impact of the addition of granddaughters (son’s daughters) on the PTA of the bull dam was evaluated. The mean change in PTAT_DAM with the addition of first granddaughters was .016, indicating that the PTAT of the bull dam was slightly underestimated. R²s for the regression of the change in bull dam’s PTAT on DTD, DTD-PA, and PTAT-PA were .39, .54, and .56 respectively. Little evidence was found to indicate a bias based on the testing population used to prove the bull. R²s for the regression of PA and PI on PTAT from the bull’s initial proof with daughter information ranged from .38 to .69, and .26 to .58 respectively. When PA and PI were used to estimate PTAT of a bull’s second proof both within and across NAAB codes, values agreed closely. / Master of Science

Call number: LD2668 .T4 1959 M55

Bulls of various breedtypes including Angus (Bos taurus), Bonsmara (Sanga X Bos taurus), Brahman (Bos indicus), Romosinuano (Criollo), Tuli (Sanga) and Wagyu (Japanese Bos taurus) were utilized to evaluate the influence of tropical adaptation on adrenal and testicular function. The objectives were to determine if tropical adaptation influenced: a) response to management stressors, b) organ and gland weights, adrenal and testis StAR and P450 content and total adrenal, medullary and cortical areas, c) basal and hCG-induced testosterone and d) testis and epididymal sperm concentrations. Blood samples were obtained within 5 min before and after transportation and during restraint every 15 min for 6 h to evaluate cortical response. Angus, Brahman and Romosinuano bulls were slaughtered following sexual maturity. Cortical responses to transportation and restraint were not influenced by tropical adaptation. Response to these stressors could be categorized into high responders (Angus, Brahman), intermediate responders (Romosinuano, Tuli) and low responders (Wagyu, Bonsmara). Tropically-adapted breedtypes were not categorized into a single group; therefore, cortical responses to management stressors were influenced by breedtype, but not by tropical adaptation. Most organ and gland weights (actual weight and weight corrected for BW) and the steroid precursors, StAR and P450, were not influenced by tropical adaptation, but were by breedtype. Paired adrenal gland weight, total adrenal area, medullary and cortical areas were influenced by tropical adaptation. Tropically-adapted breedtypes had lighter glands and smaller areas than the temperate Bos taurus breedtypes. All breedtypes except Wagyu had similar basal concentrations of plasma testosterone prior to hCG administration; therefore, basal testosterone was not influenced by tropical adaptation, but only by breedtype. Wagyu had greater basal concentrations of testosterone than other breedtypes. Testosterone concentrations following hCG administration was similar between adaptation groups and breedtypes. As expected, testis and epididymal sperm concentrations were influenced by tropical adaptation. Tropically-adapted breedtypes had greater testicular and epididymal sperm concentrations than the temperate Bos taurus breedtypes during the summer months. In summary, adrenal weight and area and testicular and epididymal sperm concentrations were influenced by tropical adaptation. Cortical response to management stressors, basal testosterone and StAR and P450 content were influenced by breedtype, not tropical adaptation.

Bulls of various breedtypes including Angus (Bos taurus), Bonsmara (Sanga X Bos taurus), Brahman (Bos indicus), Romosinuano (Criollo), Tuli (Sanga) and Wagyu (Japanese Bos taurus) were utilized to evaluate the influence of tropical adaptation on adrenal and testicular function. The objectives were to determine if tropical adaptation influenced: a) response to management stressors, b) organ and gland weights, adrenal and testis StAR and P450 content and total adrenal, medullary and cortical areas, c) basal and hCG-induced testosterone and d) testis and epididymal sperm concentrations. Blood samples were obtained within 5 min before and after transportation and during restraint every 15 min for 6 h to evaluate cortical response. Angus, Brahman and Romosinuano bulls were slaughtered following sexual maturity. Cortical responses to transportation and restraint were not influenced by tropical adaptation. Response to these stressors could be categorized into high responders (Angus, Brahman), intermediate responders (Romosinuano, Tuli) and low responders (Wagyu, Bonsmara). Tropically-adapted breedtypes were not categorized into a single group; therefore, cortical responses to management stressors were influenced by breedtype, but not by tropical adaptation. Most organ and gland weights (actual weight and weight corrected for BW) and the steroid precursors, StAR and P450, were not influenced by tropical adaptation, but were by breedtype. Paired adrenal gland weight, total adrenal area, medullary and cortical areas were influenced by tropical adaptation. Tropically-adapted breedtypes had lighter glands and smaller areas than the temperate Bos taurus breedtypes. All breedtypes except Wagyu had similar basal concentrations of plasma testosterone prior to hCG administration; therefore, basal testosterone was not influenced by tropical adaptation, but only by breedtype. Wagyu had greater basal concentrations of testosterone than other breedtypes. Testosterone concentrations following hCG administration was similar between adaptation groups and breedtypes. As expected, testis and epididymal sperm concentrations were influenced by tropical adaptation. Tropically-adapted breedtypes had greater testicular and epididymal sperm concentrations than the temperate Bos taurus breedtypes during the summer months. In summary, adrenal weight and area and testicular and epididymal sperm concentrations were influenced by tropical adaptation. Cortical response to management stressors, basal testosterone and StAR and P450 content were influenced by breedtype, not tropical adaptation.

Thesis (MSc (Production Animal Studies, Veterinary Science))--University of Pretoria, 2008. / Includes bibliographical references. Also available in print format.

Thesis (M.Inst.Agrar. (Animal Science)) -- University of Pretoria, 2003. / Abstract in English. Includes bibliographical references.