A total of 169 batches of chicken (almost 4 million pieces) were included in the survey, of which 88 batches were Cobb 500 chicken and 81 batches Ross 308 chickens. The difference in the European Production Efficiency Factor (EPEF) was 30 points in favour of the Ross 308 hybrid when compared with the Cobb 500 hybrid (395 and 365 points respectively, P < 0.05). During the monitored years, the EPEF gradually increased from 357 points in 2014 to 404 points in 2017, i.e. by 47 points (P < 0.05). From the perspective of the hatchery influence (A and B), the Ross 308 hybrid was found have almost identical EPEF (394 and 395 points respectively). The EPEF of the Cobb 500 hybrid was 27 points higher in hatchery B (380 and 353 points respectively, P < 0.05). The dependence of the live weight of the hybrid at slaughter on the age of the parent flock was found to be r = 0.41, i.e. moderate, statistically significant. A higher EPEF was achieved when fattening in green light as compared with white light. For the Cobb 500 hybrid, the difference was only 2 points (367 and 365 points respectively). For Ross 308 hybrid, the difference was higher, 11 points (404 and 393 points respectively). In the high-capacity hall, fattening took longer than in the small-capacity hall. The difference amounted to 0.92 days for the Cobb 500 hybrid (33.66 and 32.74 days respectively) and 0.11 days for the Ross 308 hybrid (33.11 and 33.00 days respectively). The differences in live weight were small, i.e. 0.01 kg for the Cobb 500 hybrid (2.09 and 2.10 kg respectively) and 0.02 kg for the Ross 308 hybrid (2.12 and 2.14 kg respectively), as were the differences in the feed mixture consumption per 1 kg weight gain, i.e. 0.02 kg for the Cobb 500 hybrid (1.57 and 1.59 kg respectively) and 0.03 kg for the Ross 308 hybrid (1.56 and 1.53 kg respectively). Higher mortality was found in the high-capacity hall. It was slightly higher, by 0.06 %, for the Cobb 500 hybrid (3.26 and 3.20 % respectively). For the Ross 308 hybrid, there was a higher difference of 0.72 % (3.46 and 2.74 % respectively). The EPEF was found to be slightly lower in the high-capacity hall compared to the low-capacity hall. The difference amounted to 9 points for the Cobb 500 hybrid (383 and 392 points respectively) and 17 points for the Ross 308 hybrid (395 and 412 points respectively).

O objetivo deste estudo foi determinar a exigência de lisina digestível para dieta de frangos de corte machos por meio das características de desempenho, composição corporal e rendimento de carcaça dos animais. Foram realizados dois ensaios, avaliando as fases de 1 a 21 e 1 a 42 dias de idade (ensaio 1), e de 22 a 42 dias de idade (ensaio 2). As dietas diferiram quanto aos níveis de lisina digestível, mantendo-se a relação dos demais aminoácidos com a lisina seguindo o conceito de proteína ideal. Foram utilizados seis tratamentos de lisina digestível na dieta dos animais até 21 dias de idade foram de: 1,026; 1,125; 1,225; 1,324; 1,423; e 1,523%; e após os 21 dias de idade: 0,877; 0,961; 1,046; 1,131; 1,216; e 1,301%. Em cada um dos ensaios, foram utilizados 1296 animais da linhagem Cobb -500®, distribuídos em 36 unidades experimentais de 36 aves cada. As características de desempenho avaliadas foram consumo de ração, peso corporal, ganho de peso, conversão alimentar, viabilidade criatória e índice de eficiência produtiva. Aos 21 dias de idade (ensaio 1) e aos 42 dias de idade (ensaios 1 e 2) foram selecionadas ao acaso sete aves por parcela experimental, cinco para avaliação do rendimento e peso de carcaça total e de cortes comerciais, e duas para avaliação da composição corporal. Os cortes comerciais avaliados foram peito, coxa, sobrecoxa e asa. Na composição corporal, avaliou-se o teor de matéria seca, extrato etéreo, matéria mineral e proteína bruta. Os dados foram submetidos à análise de variância, e havendo diferenças significativas as médias foram comparadas pelo teste de Tukey. A estimativa da exigência de lisina digestível foi realizada utilizando-se modelos de regressão linear ou quadrática. A conversão alimentar foi influenciada em todas as fases, sendo sua exigência maior que para ganho de peso. A exigência para conversão alimentar foi de 1,374; 1,243; e 1,301% para as fases de 1 a 21, 1 a 42 e 22 a 42 dias de idade, respectivamente. A lisina digestível influenciou o rendimento de peito dos animais apenas nas idades de 1 a 42 e 22 a 42 dias de idade, com exigências de 1,200 e 1,301%, respectivamente. Nas idades de 1 a 21 dias e 1 a 42 dias de idade apresentou-se diferenças na deposição proteica na carcaça, com melhores níveis à 1,305 e 1,262%, respectivamente. Níveis maiores que as recomendações conhecidas em âmbito nacional de lisina digestível trouxeram benefícios aos animais sobre conversão alimentar, rendimento de peito, deposição de proteína e gordura corporal. / The objective of the present study was to evaluate the optimal levels of digestible lysine in the diet of male broilers, evaluating performance characteristics, body composition, and carcass yield of the animals. Two trials were carried out to assess the stages from 1 to 21 and 1 to 42 days of age (assay 1), and from 22 to 42 days of age (assay 2). The diets differed in digestible lysine content, maintaining the relation among the other amino acids and lysine in accordance with the ideal protein concept. The six levels of digestible lysine in the diet of animals up to 21 days of age were: 1.026%; 1.125%; 1.225%; 1.324%; 1.423%, and 1.523%; and after 21 days of age: 0.877%; 0.961%; 1.046%; 1.131%; 1.216%, and 1.301%. A total of 1296 animals were employed in each of, distributed in 36 experimental units of 36 birds each. The determined performance characteristics corresponded to feed intake, body weight, weight gain, feed conversion, viability, and productive efficiency index (except for animals from 1 to 21 days of age). At 21 days of age (assay 1) and 42 days of age (assay 1 and 2), seven birds per experimental unit were selected at random, five for the estimation of yield and total carcass and commercial cut weight, and two for the evaluation of body composition. The commercial cuts consisted of breast, thigh, drumsticks and wing. Regarding body composition, dry matter, ethereal extract, ash, and crude protein content were calculated. The data were submitted to variance analysis, and when significant differences were observed, the means were compared using the Tukey test. The estimation of digestible lysine requirements was performed applying linear or quadratic regression models. Feed conversion was influenced in every phase, and its requirement was greater than for weight gain. The requirements for feed conversion were 1.374%; 1.243%, and 1.301% for phases from 1 to 21, 1 to 42, and 22 to 42 days of age, respectively. Digestible lysine only affected animal breast yield during the ages from 1 to 42 and 22 to 42 days of age, with requirements of 1.200% and 1.301%, respectively. At ages ranging from 1 to 21 days and 1 to 42 days of age, differences in protein deposition in the carcass were observed, displaying superior levels at 1.305% and 1.262%, respectively. With respect to nationally known recommendations regarding digestible lysine, higher levels of the amino acid in the diet have brought benefits regarding animal feed conversion, breast yield, protein deposition, and body fat.

O objetivo deste estudo foi determinar a exigência de lisina digestível para dieta de frangos de corte machos por meio das características de desempenho, composição corporal e rendimento de carcaça dos animais. Foram realizados dois ensaios, avaliando as fases de 1 a 21 e 1 a 42 dias de idade (ensaio 1), e de 22 a 42 dias de idade (ensaio 2). As dietas diferiram quanto aos níveis de lisina digestível, mantendo-se a relação dos demais aminoácidos com a lisina seguindo o conceito de proteína ideal. Foram utilizados seis tratamentos de lisina digestível na dieta dos animais até 21 dias de idade foram de: 1,026; 1,125; 1,225; 1,324; 1,423; e 1,523%; e após os 21 dias de idade: 0,877; 0,961; 1,046; 1,131; 1,216; e 1,301%. Em cada um dos ensaios, foram utilizados 1296 animais da linhagem Cobb -500®, distribuídos em 36 unidades experimentais de 36 aves cada. As características de desempenho avaliadas foram consumo de ração, peso corporal, ganho de peso, conversão alimentar, viabilidade criatória e índice de eficiência produtiva. Aos 21 dias de idade (ensaio 1) e aos 42 dias de idade (ensaios 1 e 2) foram selecionadas ao acaso sete aves por parcela experimental, cinco para avaliação do rendimento e peso de carcaça total e de cortes comerciais, e duas para avaliação da composição corporal. Os cortes comerciais avaliados foram peito, coxa, sobrecoxa e asa. Na composição corporal, avaliou-se o teor de matéria seca, extrato etéreo, matéria mineral e proteína bruta. Os dados foram submetidos à análise de variância, e havendo diferenças significativas as médias foram comparadas pelo teste de Tukey. A estimativa da exigência de lisina digestível foi realizada utilizando-se modelos de regressão linear ou quadrática. A conversão alimentar foi influenciada em todas as fases, sendo sua exigência maior que para ganho de peso. A exigência para conversão alimentar foi de 1,374; 1,243; e 1,301% para as fases de 1 a 21, 1 a 42 e 22 a 42 dias de idade, respectivamente. A lisina digestível influenciou o rendimento de peito dos animais apenas nas idades de 1 a 42 e 22 a 42 dias de idade, com exigências de 1,200 e 1,301%, respectivamente. Nas idades de 1 a 21 dias e 1 a 42 dias de idade apresentou-se diferenças na deposição proteica na carcaça, com melhores níveis à 1,305 e 1,262%, respectivamente. Níveis maiores que as recomendações conhecidas em âmbito nacional de lisina digestível trouxeram benefícios aos animais sobre conversão alimentar, rendimento de peito, deposição de proteína e gordura corporal. / The objective of the present study was to evaluate the optimal levels of digestible lysine in the diet of male broilers, evaluating performance characteristics, body composition, and carcass yield of the animals. Two trials were carried out to assess the stages from 1 to 21 and 1 to 42 days of age (assay 1), and from 22 to 42 days of age (assay 2). The diets differed in digestible lysine content, maintaining the relation among the other amino acids and lysine in accordance with the ideal protein concept. The six levels of digestible lysine in the diet of animals up to 21 days of age were: 1.026%; 1.125%; 1.225%; 1.324%; 1.423%, and 1.523%; and after 21 days of age: 0.877%; 0.961%; 1.046%; 1.131%; 1.216%, and 1.301%. A total of 1296 animals were employed in each of, distributed in 36 experimental units of 36 birds each. The determined performance characteristics corresponded to feed intake, body weight, weight gain, feed conversion, viability, and productive efficiency index (except for animals from 1 to 21 days of age). At 21 days of age (assay 1) and 42 days of age (assay 1 and 2), seven birds per experimental unit were selected at random, five for the estimation of yield and total carcass and commercial cut weight, and two for the evaluation of body composition. The commercial cuts consisted of breast, thigh, drumsticks and wing. Regarding body composition, dry matter, ethereal extract, ash, and crude protein content were calculated. The data were submitted to variance analysis, and when significant differences were observed, the means were compared using the Tukey test. The estimation of digestible lysine requirements was performed applying linear or quadratic regression models. Feed conversion was influenced in every phase, and its requirement was greater than for weight gain. The requirements for feed conversion were 1.374%; 1.243%, and 1.301% for phases from 1 to 21, 1 to 42, and 22 to 42 days of age, respectively. Digestible lysine only affected animal breast yield during the ages from 1 to 42 and 22 to 42 days of age, with requirements of 1.200% and 1.301%, respectively. At ages ranging from 1 to 21 days and 1 to 42 days of age, differences in protein deposition in the carcass were observed, displaying superior levels at 1.305% and 1.262%, respectively. With respect to nationally known recommendations regarding digestible lysine, higher levels of the amino acid in the diet have brought benefits regarding animal feed conversion, breast yield, protein deposition, and body fat.

This thesis is focused on the assessment of production of broiler chickens te. hybrids ROSS and COBB 308 500, in connection with the microclimate conditions in the period from 2011 to 2014. The survey provides calculation of average lengths of broiler fattening, live weight of broiler chickens at the end of the batch, consumption of complete feed mixture for 1 kg of live weight gain, the effectiveness index of fattening, mortality to reproductive breeding age on. The juxtaposition of these zootechnical parameters will be obtained from the company Tagrea s.r.o. with operations in Čekanice near Tabor.

The aim of the diploma thesis was to evaluate the data gained from a weighine-machine located right in the hall of the selected company. The weighine-machine together with thermometer and hygrometer measures the weight of chickens, numbers of chickens weighed, temperature, humidity and uniformity. The data acquired about the given batches are from September 2014 to March 2016 from both types of hybrids. The results show that hybrid ROSS 308 occurred more often above the growth curve, in summer months it had better daily weight gain and the highest uniformity. Hybrid COBB 500 had better increase in winter and its uniformity was higher in temporary and winter period. According to the correlation analysis, the fact was confirmed, that with the growing weight the number of chickens lowers. The average mortality was around 3 %, the exception was the batch 6/2015 when the mortality was 4,8 %.

The aim of the diploma thesis was to evaluate the performance of commercial broiler chicken genotypes Ross 308, Cobb 500 and Hubbard F15. Parental test consisted of parent rearing up to the age of 22 weeks, the laying period up to the age of 62 weeks and from fattening progeny tests (lasting for 35 days or else 42 days). Hybrid Ross 308 chickens reached the highest live weight at the end of the rearing period. Hubbard F15 chickens had the lowest feed consumption per head and day and also the lowest mortality rate. Hybrid Hubbard F15 showed the highest number of hatched chickens per 1 laying hen (137.2 pcs), the lowest feed consumption per head and day (149.4 g) and the highest fertility of hatching eggs (9,2 %). Hybrid Ross 308 showed the highest weight of hatching eggs and live weight at the end of the laying period (cockerels 5 029 g, pullets 4 310 g). Cobb 500 cockerels (2 397 g) and Hubbard F 15 pullets (2 145 g) showed the highest live weight during the 35 day fattening period. The highest breast weight was at the hybrid Cobb 500 (516.9 g) and the thighs weight was the highest at Hubbard F15 (511.9 g). The highest carcass yield was observed at hybrid Cobb 500 (76.30%). During the extended fattening period of 42 days had the highest live weight cockerels Ross 308 (3 096 g), Cobb 500 and Hubbard F15 pullets (2 688 g and 2 682 g). The highest breast weight was observed at hybrid Ross 308 (697.0 g) and thighs weight at hybrid Hubbard F15 (707.6 g). The highest carcass yield was at hybrid Hubbard F15 (78.0%).

The aim of this thesis has been to investigate what impact on sensory meat quality will purple wheat content have in the feed of broiler chicken Cobb 500. The chicken were divided in five groups, while each group was fed with a different purple wheat to control wheat ratio. The consequent sensory analysis of breast and thigh meat samples was carried out in a university sensory laboratory meeting the ISO 8589 requirement. According to the results of the following statistical assessment, both breast and thigh meat samples were judged as possessing better sensory qualities whenever they came from the chicken fed with some purple wheat content. Regarding thigh meat, best results were achieved in a group given 1/3 purple wheat and 2/3 control wheat. For breast meat, it was impossible to indicate the best ratio of wheat types. In general, however, it can also be stated that chicken fed with some purple wheat content reached better results than the control group did.