Sendo o tamanho corporal uma importante variável nos sistemas de produção pecuária no Brasil, analisaram-se os desempenhos de machos e fêmeas da raça Hereford, de diferentes tamanhos corporais, desde a desmama ao abate dos machos e ao primeiro parto nas fêmeas. Os animais foram classificados em escalas de FRAME, sendo 1, 2 e 3 chamados posteriormente de Pequenos, Médios e Grandes, respectivamente. As avaliações mensais foram capazes de mostrar diferenças de desenvolvimento e desempenho tanto em machos quanto em fêmeas em determinadas épocas do ano. As variáveis analisadas nas fêmeas foram peso e condição corporal durante todo o trabalho, variação de peso, altura da garupa, taxa de prenhez e idade ao primeiro parto. Nos machos, por sua vez, as variáveis analisadas, da desmama ao abate, foram peso, altura da garupa, variação de peso, peso de abate e características de carcaça, além do peso dos cortes comerciais e seus rendimentos. As diferenças encontradas entre as fêmeas Pequenas, Médias e Grandes, existentes em alguns parâmetros avaliados não foram capazes de afetar a taxa de prenhez aos 14 meses de idade. As diferenças de tamanhos corporais afetaram a idade à concepção, sendo as Pequenas e Médias mais jovens, porém as relações entre tamanho corporal e desempenho reprodutivo de fêmeas não ficaram totalmente evidenciadas, provavelmente pela pequena diferença entre tamanhos corporais dos animais do rebanho avaliado. Nos machos, foram determinadas diferenças de desempenho e desenvolvimento com magnitudes variadas conforme a época do ano. As diferenças de peso oscilaram em 30kg entre grupos. O tamanho corporal afetou o peso de abate, peso de carcaça quente e de alguns cortes comerciais. As diferenças encontradas, embora por vezes significativas, podem estar atribuídas à proximidade de tamanho dos grupos. Esta proximidade de tamanhos, apenas um a dois pontos na escala BIF, não permitiu observar maiores diferenças. / As the body size an important variable in livestock production systems in Brazil, analyzed the performance of males and females of Hereford, of different body sizes, from weaning to slaughter the males and in females at first calving. The animals were classified into FRAME scales, with 1, 2 and 3 later called the Small, Medium and Large, respectively. The monthly evaluations were able to show differences in development and performance in both males and females in at certain times of the year. The variables analyzed were in females weight and body condition during the whole experiment, changes in weight, hip height, pregnancy rate and age at first birth. In males, in turn, the variables analyzed, from weaning to slaughter, weight, hip height, weight variation, slaughter weight and carcass traits, along with the weight of retail cuts and their income. The differences between females Small, Medium and Large, in certain parameters were not able to affect the pregnancy rate at 14 months of age. Differences in body size affected the age at conception, and the Small and Medium younger, but the relationships between body size and reproductive performance of females were not fully observed, probably due to the small difference between body sizes of animals in the herd assessed. In males, were certain differences in performance and development with magnitudes varied depending on the season. The weight differences between groups ranged in 30kg. The body size affect the slaughter weight, hot carcass weight and some commercial cuts. The differences found, although sometimes significant, can be attributed to the proximity of group size. This proximity of sizes, just two points on a scale BIF, not allowed to observe major differences.

Sendo o tamanho corporal uma importante variável nos sistemas de produção pecuária no Brasil, analisaram-se os desempenhos de machos e fêmeas da raça Hereford, de diferentes tamanhos corporais, desde a desmama ao abate dos machos e ao primeiro parto nas fêmeas. Os animais foram classificados em escalas de FRAME, sendo 1, 2 e 3 chamados posteriormente de Pequenos, Médios e Grandes, respectivamente. As avaliações mensais foram capazes de mostrar diferenças de desenvolvimento e desempenho tanto em machos quanto em fêmeas em determinadas épocas do ano. As variáveis analisadas nas fêmeas foram peso e condição corporal durante todo o trabalho, variação de peso, altura da garupa, taxa de prenhez e idade ao primeiro parto. Nos machos, por sua vez, as variáveis analisadas, da desmama ao abate, foram peso, altura da garupa, variação de peso, peso de abate e características de carcaça, além do peso dos cortes comerciais e seus rendimentos. As diferenças encontradas entre as fêmeas Pequenas, Médias e Grandes, existentes em alguns parâmetros avaliados não foram capazes de afetar a taxa de prenhez aos 14 meses de idade. As diferenças de tamanhos corporais afetaram a idade à concepção, sendo as Pequenas e Médias mais jovens, porém as relações entre tamanho corporal e desempenho reprodutivo de fêmeas não ficaram totalmente evidenciadas, provavelmente pela pequena diferença entre tamanhos corporais dos animais do rebanho avaliado. Nos machos, foram determinadas diferenças de desempenho e desenvolvimento com magnitudes variadas conforme a época do ano. As diferenças de peso oscilaram em 30kg entre grupos. O tamanho corporal afetou o peso de abate, peso de carcaça quente e de alguns cortes comerciais. As diferenças encontradas, embora por vezes significativas, podem estar atribuídas à proximidade de tamanho dos grupos. Esta proximidade de tamanhos, apenas um a dois pontos na escala BIF, não permitiu observar maiores diferenças. / As the body size an important variable in livestock production systems in Brazil, analyzed the performance of males and females of Hereford, of different body sizes, from weaning to slaughter the males and in females at first calving. The animals were classified into FRAME scales, with 1, 2 and 3 later called the Small, Medium and Large, respectively. The monthly evaluations were able to show differences in development and performance in both males and females in at certain times of the year. The variables analyzed were in females weight and body condition during the whole experiment, changes in weight, hip height, pregnancy rate and age at first birth. In males, in turn, the variables analyzed, from weaning to slaughter, weight, hip height, weight variation, slaughter weight and carcass traits, along with the weight of retail cuts and their income. The differences between females Small, Medium and Large, in certain parameters were not able to affect the pregnancy rate at 14 months of age. Differences in body size affected the age at conception, and the Small and Medium younger, but the relationships between body size and reproductive performance of females were not fully observed, probably due to the small difference between body sizes of animals in the herd assessed. In males, were certain differences in performance and development with magnitudes varied depending on the season. The weight differences between groups ranged in 30kg. The body size affect the slaughter weight, hot carcass weight and some commercial cuts. The differences found, although sometimes significant, can be attributed to the proximity of group size. This proximity of sizes, just two points on a scale BIF, not allowed to observe major differences.

The history of English rural society in the Middle Ages generally is written on the basis of records produced by manorial lords which register the dues and obligations of tenants as well as changes in holdings, fines and other legal transactions which touch on the lives of the villagers. This thesis is a critical study of the potential uses of a group of such sources for an historical "reconstruction" of medieval rural conditions. The records under review refer to Ombersley, a Midlands manor belonging to the Benedictine abbey of Evesham, and cover the period of the fourteenth and fifteenth century. While by no means complete, they have survived to an extent that a special study of their value and the problems connected with them is warranted. A brief introduction on the geographic and settlement conditions of the manor (Ch. 1) is followed by a survey of the quality and quantity of the collection of Ombersley account rolls, court records and rentals, summarized in a calendar (Ch. 2 and Appendix). Recent works on the "reconstitution" of medieval rural communities have raised a number of questions on the use of such records; the present thesis attempts to focus this discussion to the use and misuse of rentals (surveys). The importance of this type of document in the study of population trends, land distribution and related aspects of manorial life derives from its wealth of detail. However, owing to their seigneurial point of view and "static" character, rentals are not as reliable as often assumed. The problems connected with them are discussed and illustrated by an analysis of two extensive rentals of Ombersley, presented in an annotated tabulation, combining their data with those extracted from court rolls and other manorial records (Ch. 3). These juxtapositions enable us to date these and other surveys correctly and to identify the "careers" of a good number of individuals and families on the manor. Based on the critical evaluation of these interrelated sources, a summary of the major demographic and economic trends is offered for the two centuries under review, including calculations of the manor's population, mortality rate, reproductive capacity and its economic development as reflected in the payment of different seigneurial dues. Bearing in mind some of the common pitfalls of generalization, I plan to use these data as a basis for monographic treatment of social stratification and other details in Ombersley's history. / Arts, Faculty of / History, Department of / Graduate

no abstract provided by author / Master of Science

no abstract provided by author / Master of Science

Lactation and weaning weight relationships were studied in 37 cows grazing Southern Utah irrigated pastures during the summer of 1979. The herd included 23 Hereford cows ranging in age from 2 to 12 years and 14 Simmental-Hereford half-blood cows aged 3 to 9 years. The suckling calves were sired by Hereford bulls. The average daily milk yield of 6.16 kg was affected by the cow breed. Simmental-Hereford cows produced 7.11 kg of milk per day, while the Herefords produced 5.21 kg per day. Milk production declined with increased days in lactation. The decline was linear in the Simmental- Hereford cows and quadratic in the Herefords. Milk production was also affected by the sex of the suckling calf. Heifer calves received 6.44 kg per day compared t o 5.80 kg per day for bull calves. Calf birth weight and test day weight influenced milk yield as cows nursing heavier calves produced more milk. Cow breed affected milk composition. Simmental-Hereford cows had higher percent solids-not-fat, while Herefords were higher for percent protein. Calf weights were affected by sex of calf. Bull calves weighed 33 .89 kg at birth, while heifers weighed 32.14 kg. At weaning, bulls weighed 188.63 kg, while heifers weighed 177.14 kg. While no breed difference was evident for birth weight, calves from Simmental-Hereford dams weighed more over the duration of the study than calves from Hereford dams. The difference between the mean 205-day adjusted weights for the calves from the Simmental-Hereford and Hereford cows was 24.96 kg (230.50 kg and 205.54 kg, respectively). Milk yield was highly correlated to calf gain (r 0. 71). The breed of dam influence upon weaning weight was largely a result of differences .in quantity of milk produced.

Data from 75 F2 Brahman-Hereford cows of four specific breed combinations, F2 HB (produced by F1 HB sires x F1 HB dams, where “HB” refers to cattle sired by Hereford bulls and out of Brahman cows), F2 BH (produced by F1 BH sires x F1 BH dams), HB x BH and BH x HB, were evaluated for maternal performance at the Texas A&M Research Center near McGregor. Differences between breed combinations were analyzed for calf crop born (CCB), calf crop weaned (CCW), calf survival (CS), birth weight (BW), weaning weight (WW), and cow weight at palpation (PW). The adjusted means for F2 HB, F2 BH, HB x BH, and BH x HB were 0.84 ± 0.06, 0.57 ± 0.07, 0.82 ± 0.06, and 0.62 ± 0.08, respectively, for CCW. F2 HB cows had a 0.27 ± 0.09 higher percent calf crop weaned than F2 BH cows (P < 0.01) and a 0.22 ± 0.11 higher percent calf crop weaned than BH x HB cows (P < 0.05). HB x BH cows had a 0.25 ± 0.08 higher percent calf crop weaned than F2 BH (P < 0.01) and a 0.20 ± 0.10 higher percent calf crop weaned than BH x HB cows (P < 0.05). As 6-year-olds, the adjusted means for cow weight at palpation for F2 HB, F2 BH, HB x BH, and BH x HB cows were 523.65 ± 20.49 kg, 602.61 ± 23.63 kg, 492.84 ± 16.98 kg, and 515.93 ± 22.96 kg, respectively. Averaged across all ages, HB x BH cows weighed 56.59 ± 15.29 kg less than F2 BH cows (P < 0.001) and 41.11 ± 18.92 kg less than BH x HB cows (P < 0.05). Also, F2 HB cows weighed 40.45 ± 17.68 kg less than F2 BH cows (P < 0.05). In this herd, HB-sired cows had higher reproductive efficiency than BH-sired cows. Also, HB-sired cows tended to be lighter than BH-sired cows. Although these differences existed, exact causes could not be determined primarily due to confounding between the birth year of the cow and the sire breed of the cow.

M.S.

M.S.

A simulation approach was used to determine the effects of multitrait selection on the correlations of sire direct and maternal predicted breeding values across environments. True and predicted direct and maternal breeding values (BV) of sires were simulated for sires evaluated independently in two different environments. Prediction error variances and covariances among direct and maternal BV within environments were required for the simulation. To obtain the necessary input parameters, a variety of MME coefficient matrices were created and inverted to inspect relationship among accuracies and correlations of prediction errors in sire evaluation models. An empirical prediction equation to predict the necessary prediction error covariances was obtained. Divergent, directional and random multitrait selection was then practiced using direct and maternal predicted BV as selection criteria. Samples of 40 sires were randomly obtained from each selected population. Observed correlations between direct and maternal predicted BV across environments were compared to expectations derived from univariate distribution theory. Selection definitely affected the expectations. However, the adjustment developed from univariate theory appeared to accommodate the effect of selection in these expectations. / Ph. D.