The purpose of this thesis was to evaluate the level of performance of Aberdeen Angus beef cattle breed bred in Less-favoured areas in southern Bohemia. This evaluation was carried out on Mr. Lepša?s farm in the years 2010 and 2011. 74 basic herd cows and 108 purebred calves born during this period were selected for this purpose. The date of birth, number of births, age at first calving and the average time interval between calving were checked on cows and the date of birth, the weight at birth and the weight in the age of 120 and 210 days were checked on calves. Average daily increments in the interval from birth to 120 days of age, from 120 to 210 days of age and from the day of birth to 210 days were calculated. The group of calves was sorted out by following parameters. Year of birth; sex and year of birth; month of birth; order of calving of the mother. Microsoft Excel was used for processing the statistic data. Basic statistical characteristics for the monitored parameters were calculated and differences between groups were verified by single-factor analysis of variance (F-test) and paired t-tests for the corresponding levels of significance. Breeding cows were evaluated by age and number of births. Cows with 1 (23%) or 2 (17.6%) births are represented in the largest number in the herd including even the cows with 15 births. Cows at first calving reached an average age of 813 days and average length of the interval between calving was 393 days. Calves regardless of sex reached the average birth weight of 33.72 kg in the year 2010, 33.31 kg in 2011, in 120 days of age the average live weight reached 207.95 kg in 2010, 202.94 kg in 2011 and calves in 210 days of age reached an average weight of 309.61 kg in 2010 and in 2011 306.09 kg. Average daily gain of calves from birth to 120 days reached 1451 g in 2010, 1.413 g in 2011, between 120 and 210 days of age the average daily gain was 1413 g in 2010, 1169 in 2011 and in the period from birth to 210 days of age it was 1314 g in 2010 and 1299 g in 2011. Analysis of breeding from economic perspective by comparing revenues (including subventions) and expenditures in each year resulted in findings that the breeding is moderately profitable and it follows that without subventions which constitute an important part of the revenue would be difficult to realize this breeding.

The objective of this study was to estimate genetic and phenotypic parameters, besides the genetic progress for the performance traits post-weaning in a population of Charolais cattle. Components of (co)variance were estimated using an animal model by Bayesian inference method. In the first article was analyzed the average daily gain from weaning to yearling (ADGWY) and weight adjusted to 550 days of age (W550) of 5.897 animals, sired by 181 bulls and 3.897 cows born between 1983 and 1999. The average for direct heritability and standard errors were 0.39±0.04 and 0.48±0.05 for ADGWY and W550, respectively. The genetic correlation between the two traits analyzed and the standard error was 0.60±0.05. The genetic trends for ADGWY and W550 were -0.058g/year and -0.019kg/. In the second article were estimated parameters and genetics trends for visual scores as well as their associations with the average daily gain from weaning to yearling (ADGWY) and weight adjusted to 550 days of age (W550) of 2.964 animals, sired by 145 bulls and 1.820 cows born between 1994 and 2007. The heritability estimates for scores of conformation (C), precocity (P), muscle (M) and size (S) were: 0.13±0.04, 0.23±0.04, 0.16±0.03 and 0.11±0.04, respectively. The genetic correlation between the four visual scores ranged between -0.03 and 0.83. The genetic correlations between ADGWY and W550 with visual scores were negative, ranging from - 0.07 to -0.82. As for the study of genetic progress, the genetic trends for C, P, M and S were: 0.0019, 0.0027, 0.0017 and 0.0011, respectively. / Este estudo teve como objetivo estimar parâmetros genéticos, além do progresso genético para as características de desempenho na pós-desmama em uma população bovina da raça Charolês. Os componentes de (co)variâncias foram estimados utilizando um modelo animal, através do método de inferência Bayesiana. No primeiro capítulo foram analisadas as características ganho médio diário da desmama ao sobreano (GMDDS) e o peso ajustado aos 550 dias de idade (P550) de 5.897 animais, filhos de 181 touros e 3.897 vacas, nascidos entre 1983 e 1999. As médias a posteriori para a herdabilidade direta e os erros padrões foram 0,39±0,04 e 0,48±0,05 para GMDDS e P550, respectivamente. A correlação genética entre as duas características analisadas e o erro padrão foi 0,60±0,05. As tendências genéticas estimadas para GMDDS e P550 foram -0,058g/ano e -0,019kg/ano. No segundo capítulo foram estimados parâmetros e tendências genéticas para os escores visuais, bem como suas associações com o ganho médio diário da desmama ao sobreano (GMDDS) e o peso ajustado aos 550 dias de idade (P550) de 2.964 animais, filhos de 145 touros e 1.820 vacas, nascidos entre 1994 e 2007. As herdabilidades estimadas para os escores de conformação (C), precocidade (P), musculatura (M) e tamanho (T) foram: 0,13±0,04, 0,23±0,04, 0,16±0,03, 0,11±0,04, respectivamente. A correlação genética entre os quatro escores variaram entre - 0,03 e 0,83. Já as correlações genéticas entre GMDDS e P550 com os escores visuais foram todas negativas, variando de -0,07 a -0,82. Quanto ao estudo do progresso genético, as tendências genéticas para C, P, M e T foram: 0,0019, 0,0027, 0,0017 e 0,0011, respectivamente.