Effects of breeder age on embryonic development, hatching results, chick quality, and growing performance of the slow-growing genotype.

The present study aimed to ascertain the effects of slow-growing breeder age on embryo development, incubation results, and chick quality and of the interaction between breeder age and hatching time on initial performance. A total of 630 hatching eggs obtained from a commercial flock of slow-growing broiler breeders (Isa Label Naked Neck) were evaluated in 2 experiments. The first experiment evaluated embryo development and hatching results for broiler breeder age treatments of 38 and 51 wk, whereas the second experiment evaluated broiler chick performance. For the second experiment, chicks were distributed in a 2 x 2 factorial randomized block (sex) experimental design consisting of 2 breeder ages (31 or 58 wk) and 2 hatching times (479-485 and 491-497 h). At 18 d of embryonic development, embryos of 51-wk-old breeders were larger than those of 38-wk-old breeders (P < 0.05), whereas yolk-free chick weight was similar (P > 0.05). Embryo organ weight was similar for the 2 breeder ages (P > 0.05); however, there was greater development of intestinal villi for embryos of the 51-wk-old breeders. There were no differences between breeder ages in hatchability and chick quality score (P > 0.05). Yolk-free chick weight at pulling was greater (P < 0.05) for chicks from 51-wk-old breeders. Hatching time did not affect performance from 1 to 7 d (P > 0.05); however, chicks hatching at 491-497 h had better performance from 1 to 28 d than did chicks hatching at 479-485 h (P < 0.05). In conclusion, the age of slow-growing breeders affects embryo villi development and chick weight but does not improve incubation results or chick quality. Chicks hatching later (491-497 h) had better performance results than chicks hatching earlier (479-485 h).

Effect of Production Systems and Dietary Interventions on Growth Performance, Morphometrics, Physiological Response and Behaviour of the Naked Neck Chickens

The present study was planned to evaluate the growth performance, morphometrics, physiological and behavioral response of Naked Neck chicken under different production systems and nutritional regimens. For this, a total of 900 Naked Neck chickens of 6-weeks of age were used; the birds were divided into 10 treatment groups consisting of 5 replicates of 18 birds each. A 2×5 factorial arrangement of treatment was employed under Completely Randomized Design. Treatments were consisted of two production systems (intensive and free range) and five nutritional regimens (100% commercial feed, 75% commercial feed +25% kitchen waste, 50% commercial feed +50% kitchen waste, 25% commercial feed +75% kitchen waste and 100% kitchen waste). Body weight, heartbeat and respiration rate were higher in birds reared under intensive system and spent most of their time sitting whereas higher feed intake and increased pecking behavior were noted in birds reared under free range system. Regarding feeding regimens, higher feed intake, cloacal temperature, body and neck length were observed in birds fed with 100% kitchen waste whereas higher drumstick, shank and wing spread were observed in birds fed under 100% commercial feed. Furthermore, higher shank and neck length were observed in birds fed 75% kitchen waste and higher body weight was observed in birds fed 50% kitchen waste. Significant interactions were also observed regarding feed intake, cloacal temperature, drumstick circumference, shank length, feeding, sitting and walking behavior. In conclusion, Naked Neck chicken perform better in free range system whereas feeding kitchen waste up to 50% may enhance growth, morphometric, physiological traits and improve behavioral response.(AU)

Effect of Production Systems and Dietary Interventions on Growth Performance, Morphometrics, Physiological Response and Behaviour of the Naked Neck Chickens

The present study was planned to evaluate the growth performance, morphometrics, physiological and behavioral response of Naked Neck chicken under different production systems and nutritional regimens. For this, a total of 900 Naked Neck chickens of 6-weeks of age were used; the birds were divided into 10 treatment groups consisting of 5 replicates of 18 birds each. A 2×5 factorial arrangement of treatment was employed under Completely Randomized Design. Treatments were consisted of two production systems (intensive and free range) and five nutritional regimens (100% commercial feed, 75% commercial feed +25% kitchen waste, 50% commercial feed +50% kitchen waste, 25% commercial feed +75% kitchen waste and 100% kitchen waste). Body weight, heartbeat and respiration rate were higher in birds reared under intensive system and spent most of their time sitting whereas higher feed intake and increased pecking behavior were noted in birds reared under free range system. Regarding feeding regimens, higher feed intake, cloacal temperature, body and neck length were observed in birds fed with 100% kitchen waste whereas higher drumstick, shank and wing spread were observed in birds fed under 100% commercial feed. Furthermore, higher shank and neck length were observed in birds fed 75% kitchen waste and higher body weight was observed in birds fed 50% kitchen waste. Significant interactions were also observed regarding feed intake, cloacal temperature, drumstick circumference, shank length, feeding, sitting and walking behavior. In conclusion, Naked Neck chicken perform better in free range system whereas feeding kitchen waste up to 50% may enhance growth, morphometric, physiological traits and improve behavioral response.

Diet metabolisability and performance of slow-growing chickens fed with cottonseed cake / Metabolizabilidade das dietas e desempenho dos frangos de crescimento lento alimentados com torta de algodão

The aim of this study was to evaluate poultry performance and diet metabolisability in slow- growing naked neck chickens fed different substitution levels of soybean meal protein with cottonseed cake protein. The trial was conducted in a completely randomized design with five treatments (0, 10, 20, 30 and 40% substitution of soybean meal protein with cottonseed cake protein), six replicates and fifteen birds per replicate. The birds and diets of each experimental unit were weighed at one day old. At 30, 60 and 85 days old, the chickens and leftovers were weighed again to estimate the feed intake (FI), weight gain (WG), feed conversion (FC) and final weight (FW) from 1 to 30 days, from 1 to 60 days and from 1 to 85 days old. To evaluate diet metabolisability, a three-day total excreta collection (26 to 28 days of age) was performed. A quadratic effect was reported for diet metabolisability, in which the minimum substitution level was 17.45% and 17.69% for apparent metabolisable energy (AME) and nitrogen-corrected apparent metabolisable energy (AMEn), respectively. Based on performance, it is recommended to replace 40% soybean meal protein with cottonseed cake protein.(AU)

O objetivo desse estudo foi avaliar o desempenho das aves e a metabolizabilidade das dietas de frangos de crescimento lento, da linhagem pescoço pelado, alimentados níveis distintos de substituição da proteína do farelo de soja pela proteína da torta de algodão. O experimento foi conduzido em delineamento inteiramente casualizado com cinco tratamentos (0, 10, 20, 30 e 40% de substituição da proteína do farelo de soja pela proteína da torta de algodão), seis repetições e quinze aves por repetição. Com um dia de idade foram pesadas as aves e as dietas de cada unidade experimental. E aos 30, 60 e 85 dias de idade as aves e as sobras das dietas foram pesadas novamente para contabilizar o consumo de ração (CR), ganho de peso (GP), conversão alimentar (CA) e peso final (PF) das aves no período de 1 a 30 dias, de 1 a 60 dias e de 1 a 85 dias de idade. Para avaliação da metabolizabilidade das dietas foi realizada a coleta total de excretas por três dias (26 a 28 dias de idade). Foi identificado efeito quadrático no ensaio de metabolizabilidade das dietas em que o nível mínimo de substituição foi de 17,45% e 17,69% para EMA e EMAn, respectivamente. Com base no desempenho recomenda-se 40% de substituição da proteína do farelo de soja pela proteína da torta de algodão.(AU)

Effect of Breeder Age on the Progeny Performance of Three Naked-Neck Chicken Phenotypes

The study was planned to evaluate the effect of different naked-neck (NN) chicken genotypes and breeder ages on the growth performance of their progenies. A total of 126 chicks, from two breeder ages and three NN varieties, were reared up to 20 weeks of age. A randomized complete block design in factorial arrangement, with six treatments of seven replicates of two females and one male each, was applied. Treatments consisted of three NN varieties (light brown, black, and dark brown) and two breeder age groups (45 and 55 weeks old). Growth performance (body weight gain, feed intake and feed conversion ratio) were evaluated. Higher feed intake was observed in both the male and female progenies of 55-week-old compared with 45-week-old breeders. Light brown males had higher weight gain than dark brown males, whereas in the female progeny, higher weight gain was obtained in the black variety than that in the light brown and dark brown varieties. Regarding breeder age groups, both male and female progenies of 55-week-oldbreeders exhibited higher weight gain than those of 45-week-old breeders. The male progeny of 55-week-old black breeders showed the highest body weight gain among all treatments. Regarding female progeny, higher weight gain was observed in the black variety compared with the light brown and dark brown variety, and in the progeny of 55-week-old breeders than in the progeny of 45-week-old breeders. The interaction between factors showed that females from 55-week-old black breeder has the highest weight gain, whereas the lowest weight gain was found in the progeny of 45-week-old light brown breeders. The male progeny of light brown breeders showed better FCR than those of black and dark brown breeders and of 55-week-old breeders compared with that of 45-week-old breeders. The best FCR was obtained in the progeny of 55-week-old light brown breeders. In females, while no influence of breeder age was detected, better FCR was determined in black than in dark brown and light brown varieties; however, the interaction between factors was significant, with the best FCR obtained in the female progeny of 55-week-old black breeders, and worst in the progeny of 45-week-old light brown breeders. In conclusion, the light brown and black varieties of naked-neck chickens and the progeny of 55-week-old breeders presented better growth performance.(AU)

Diet metabolisability and performance of slow-growing chickens fed with cottonseed cake / Metabolizabilidade das dietas e desempenho dos frangos de crescimento lento alimentados com torta de algodão

The aim of this study was to evaluate poultry performance and diet metabolisability in slow- growing naked neck chickens fed different substitution levels of soybean meal protein with cottonseed cake protein. The trial was conducted in a completely randomized design with five treatments (0, 10, 20, 30 and 40% substitution of soybean meal protein with cottonseed cake protein), six replicates and fifteen birds per replicate. The birds and diets of each experimental unit were weighed at one day old. At 30, 60 and 85 days old, the chickens and leftovers were weighed again to estimate the feed intake (FI), weight gain (WG), feed conversion (FC) and final weight (FW) from 1 to 30 days, from 1 to 60 days and from 1 to 85 days old. To evaluate diet metabolisability, a three-day total excreta collection (26 to 28 days of age) was performed. A quadratic effect was reported for diet metabolisability, in which the minimum substitution level was 17.45% and 17.69% for apparent metabolisable energy (AME) and nitrogen-corrected apparent metabolisable energy (AMEn), respectively. Based on performance, it is recommended to replace 40% soybean meal protein with cottonseed cake protein.

O objetivo desse estudo foi avaliar o desempenho das aves e a metabolizabilidade das dietas de frangos de crescimento lento, da linhagem pescoço pelado, alimentados níveis distintos de substituição da proteína do farelo de soja pela proteína da torta de algodão. O experimento foi conduzido em delineamento inteiramente casualizado com cinco tratamentos (0, 10, 20, 30 e 40% de substituição da proteína do farelo de soja pela proteína da torta de algodão), seis repetições e quinze aves por repetição. Com um dia de idade foram pesadas as aves e as dietas de cada unidade experimental. E aos 30, 60 e 85 dias de idade as aves e as sobras das dietas foram pesadas novamente para contabilizar o consumo de ração (CR), ganho de peso (GP), conversão alimentar (CA) e peso final (PF) das aves no período de 1 a 30 dias, de 1 a 60 dias e de 1 a 85 dias de idade. Para avaliação da metabolizabilidade das dietas foi realizada a coleta total de excretas por três dias (26 a 28 dias de idade). Foi identificado efeito quadrático no ensaio de metabolizabilidade das dietas em que o nível mínimo de substituição foi de 17,45% e 17,69% para EMA e EMAn, respectivamente. Com base no desempenho recomenda-se 40% de substituição da proteína do farelo de soja pela proteína da torta de algodão.

Effect of Breeder Age on the Progeny Performance of Three Naked-Neck Chicken Phenotypes

The study was planned to evaluate the effect of different naked-neck (NN) chicken genotypes and breeder ages on the growth performance of their progenies. A total of 126 chicks, from two breeder ages and three NN varieties, were reared up to 20 weeks of age. A randomized complete block design in factorial arrangement, with six treatments of seven replicates of two females and one male each, was applied. Treatments consisted of three NN varieties (light brown, black, and dark brown) and two breeder age groups (45 and 55 weeks old). Growth performance (body weight gain, feed intake and feed conversion ratio) were evaluated. Higher feed intake was observed in both the male and female progenies of 55-week-old compared with 45-week-old breeders. Light brown males had higher weight gain than dark brown males, whereas in the female progeny, higher weight gain was obtained in the black variety than that in the light brown and dark brown varieties. Regarding breeder age groups, both male and female progenies of 55-week-oldbreeders exhibited higher weight gain than those of 45-week-old breeders. The male progeny of 55-week-old black breeders showed the highest body weight gain among all treatments. Regarding female progeny, higher weight gain was observed in the black variety compared with the light brown and dark brown variety, and in the progeny of 55-week-old breeders than in the progeny of 45-week-old breeders. The interaction between factors showed that females from 55-week-old black breeder has the highest weight gain, whereas the lowest weight gain was found in the progeny of 45-week-old light brown breeders. The male progeny of light brown breeders showed better FCR than those of black and dark brown breeders and of 55-week-old breeders compared with that of 45-week-old breeders. The best FCR was obtained in the progeny of 55-week-old light brown breeders. In females, while no influence of breeder age was detected, better FCR was determined in black than in dark brown and light brown varieties; however, the interaction between factors was significant, with the best FCR obtained in the female progeny of 55-week-old black breeders, and worst in the progeny of 45-week-old light brown breeders. In conclusion, the light brown and black varieties of naked-neck chickens and the progeny of 55-week-old breeders presented better growth performance.

Lisina digestível em rações para frangos de corte tipo caipira

SUMMARY Two experiments were carried in order to determine digestible lysine requirements for free-range broiler hillbilly, Redbro lineage, males and females, created in free range system during the growing (43 to 56) and final phases (57 to 70 days). For this, 630 chickens were housed in 30 pens with pasture area and the experimental design was completely randomized in a factorial arrangement 5x2 (lysine and gender), with three replications with 21 chicks each. The digestible lysine levels evaluated were: 6.07, 7.07, 8.07, 9.07 and 10.07 (growth phase) and 6.00, 7.00, 8.00, 9.00 and 10.00 g/kg (final phase). Were evaluated the performance, the carcass and cuts yield, abdominal fat and meat quality characteristics. For the growth phase there were no differences of lysine levels on performance of the chiks, except for the consumption of digestible lysine. Therefore, the level of 6.07 g lysine /kg of diet meet the requirements of broilers of both genders. For the final phase it we observed effect of digestible lysine levels only to feed conversion, and the level of 8.51 g of lysine/kg of diet improve this trait.

RESUMO Dois experimentos foram realizados com o objetivo de determinar as exigências de lisina digestível para frangos tipo caipira, linhagem Redbro machos e fêmeas, criados em semiconfinamento durante as fases de crescimento (43 a 56) e final (57 a 70 dias). Para isso, 630 frangos foram alojados em 30 boxes com área de pastejo e o delineamento experimental utilizado foi inteiramente casualizado em arranjo fatorial 5x2 (lisina digestível e sexo) e três repetições com 21 aves cada. Os níveis de lisina digestível avaliados foram: 6,07; 7,07; 8,07; 9,07 e 10,07g/kg (fase de crescimento) e 6,00; 7,00; 8,00; 9,00 e 10,00g/kg (fase final). Avaliou-se o desempenho, o rendimento de carcaça e cortes, gordura abdominal e características da qualidade da carne. Para a fase de crescimento não houve diferenças dos níveis de lisina sobre o desempenho dos frangos, exceto para o consumo de lisina digestível. Portanto, o nível de 6,07 g de lisina digestível/kg de ração atende as exigências dos frangos de ambos os sexos. Para a fase final observou-se efeito dos níveis de lisina digestível somente para a conversão alimentar, sendo o nível de 8,51 g de lisina /kg de ração o que melhora essa variável.

Digestible lysine in rations for free range broiler chickens / Lisina digestível em rações para frangos de corte tipo caipira

Two experiments were carried in order to determine digestible lysine requirements for free-range broiler hillbilly, Redbro lineage, males and females, created in free range system during the growing (43 to 56) and final phases (57 to 70 days). For this, 630 chickens were housed in 30 pens with pasture area and the experimental design was completely randomized in a factorial arrangement 5x2 (lysine and gender), with three replications with 21 chicks each. The digestible lysine levels evaluated were: 6.07, 7.07, 8.07, 9.07 and 10.07 (growth phase) and 6.00, 7.00, 8.00, 9.00 and 10.00 g/kg (final phase). Were evaluated the performance, the carcass and cuts yield, abdominal fat and meat quality characteristics. For the growth phase there were no differences of lysine levels on performance of the chiks, except for the consumption of digestible lysine. Therefore, the level of 6.07 g lysine /kg of diet meet the requirements of broilers of both genders. For the final phase it we observed effect of digestible lysine levels only to feed conversion, and the level of 8.51 g of lysine/kg of diet improve this trait.(AU)

Dois experimentos foram realizados com o objetivo de determinar as exigências de lisina digestível para frangos tipo caipira, linhagem Redbro machos e fêmeas, criados em semiconfinamento durante as fases de crescimento (43 a 56) e final (57 a 70 dias). Para isso, 630 frangos foram alojados em 30 boxes com área de pastejo e o delineamento experimental utilizado foi inteiramente casualizado em arranjo fatorial 5x2 (lisina digestível e sexo) e três repetições com 21 aves cada. Os níveis de lisina digestível avaliados foram: 6,07; 7,07; 8,07; 9,07 e 10,07g/kg (fase de crescimento) e 6,00; 7,00; 8,00; 9,00 e 10,00g/kg (fase final). Avaliou-se o desempenho, o rendimento de carcaça e cortes, gordura abdominal e características da qualidade da carne. Para a fase de crescimento não houve diferenças dos níveis de lisina sobre o desempenho dos frangos, exceto para o consumo de lisina digestível. Portanto, o nível de 6,07 g de lisina digestível/kg de ração atende as exigências dos frangos de ambos os sexos. Para a fase final observou-se efeito dos níveis de lisina digestível somente para a conversão alimentar, sendo o nível de 8,51 g de lisina /kg de ração o que melhora essa variável.(AU)

Digestible lysine in rations for free range broiler chickens / Lisina digestível em rações para frangos de corte tipo caipira

Two experiments were carried in order to determine digestible lysine requirements for free-range broiler hillbilly, Redbro lineage, males and females, created in free range system during the growing (43 to 56) and final phases (57 to 70 days). For this, 630 chickens were housed in 30 pens with pasture area and the experimental design was completely randomized in a factorial arrangement 5x2 (lysine and gender), with three replications with 21 chicks each. The digestible lysine levels evaluated were: 6.07, 7.07, 8.07, 9.07 and 10.07 (growth phase) and 6.00, 7.00, 8.00, 9.00 and 10.00 g/kg (final phase). Were evaluated the performance, the carcass and cuts yield, abdominal fat and meat quality characteristics. For the growth phase there were no differences of lysine levels on performance of the chiks, except for the consumption of digestible lysine. Therefore, the level of 6.07 g lysine /kg of diet meet the requirements of broilers of both genders. For the final phase it we observed effect of digestible lysine levels only to feed conversion, and the level of 8.51 g of lysine/kg of diet improve this trait.

Dois experimentos foram realizados com o objetivo de determinar as exigências de lisina digestível para frangos tipo caipira, linhagem Redbro machos e fêmeas, criados em semiconfinamento durante as fases de crescimento (43 a 56) e final (57 a 70 dias). Para isso, 630 frangos foram alojados em 30 boxes com área de pastejo e o delineamento experimental utilizado foi inteiramente casualizado em arranjo fatorial 5x2 (lisina digestível e sexo) e três repetições com 21 aves cada. Os níveis de lisina digestível avaliados foram: 6,07; 7,07; 8,07; 9,07 e 10,07g/kg (fase de crescimento) e 6,00; 7,00; 8,00; 9,00 e 10,00g/kg (fase final). Avaliou-se o desempenho, o rendimento de carcaça e cortes, gordura abdominal e características da qualidade da carne. Para a fase de crescimento não houve diferenças dos níveis de lisina sobre o desempenho dos frangos, exceto para o consumo de lisina digestível. Portanto, o nível de 6,07 g de lisina digestível/kg de ração atende as exigências dos frangos de ambos os sexos. Para a fase final observou-se efeito dos níveis de lisina digestível somente para a conversão alimentar, sendo o nível de 8,51 g de lisina /kg de ração o que melhora essa variável.

Lisina digestível em rações para frangos de corte tipo caipira

SUMMARY Two experiments were carried in order to determine digestible lysine requirements for free-range broiler hillbilly, Redbro lineage, males and females, created in free range system during the growing (43 to 56) and final phases (57 to 70 days). For this, 630 chickens were housed in 30 pens with pasture area and the experimental design was completely randomized in a factorial arrangement 5x2 (lysine and gender), with three replications with 21 chicks each. The digestible lysine levels evaluated were: 6.07, 7.07, 8.07, 9.07 and 10.07 (growth phase) and 6.00, 7.00, 8.00, 9.00 and 10.00 g/kg (final phase). Were evaluated the performance, the carcass and cuts yield, abdominal fat and meat quality characteristics. For the growth phase there were no differences of lysine levels on performance of the chiks, except for the consumption of digestible lysine. Therefore, the level of 6.07 g lysine /kg of diet meet the requirements of broilers of both genders. For the final phase it we observed effect of digestible lysine levels only to feed conversion, and the level of 8.51 g of lysine/kg of diet improve this trait.

RESUMO Dois experimentos foram realizados com o objetivo de determinar as exigências de lisina digestível para frangos tipo caipira, linhagem Redbro machos e fêmeas, criados em semiconfinamento durante as fases de crescimento (43 a 56) e final (57 a 70 dias). Para isso, 630 frangos foram alojados em 30 boxes com área de pastejo e o delineamento experimental utilizado foi inteiramente casualizado em arranjo fatorial 5x2 (lisina digestível e sexo) e três repetições com 21 aves cada. Os níveis de lisina digestível avaliados foram: 6,07; 7,07; 8,07; 9,07 e 10,07g/kg (fase de crescimento) e 6,00; 7,00; 8,00; 9,00 e 10,00g/kg (fase final). Avaliou-se o desempenho, o rendimento de carcaça e cortes, gordura abdominal e características da qualidade da carne. Para a fase de crescimento não houve diferenças dos níveis de lisina sobre o desempenho dos frangos, exceto para o consumo de lisina digestível. Portanto, o nível de 6,07 g de lisina digestível/kg de ração atende as exigências dos frangos de ambos os sexos. Para a fase final observou-se efeito dos níveis de lisina digestível somente para a conversão alimentar, sendo o nível de 8,51 g de lisina /kg de ração o que melhora essa variável.

Levels of digestible lysine for free-range broiler chickens from 28 to 56 days of age / Níveis de lisina digestível para frangos de corte tipo caipira de 28 a 56 dias de idade

The objective of this study was to evaluate digestible lysine levels for free-range broiler hillbilly, from 28 to 56 days old. We used 720 naked neck chickens slow-growing Label Rouge strain males, distributed in a completely randomized design with six digestible lysine levels (0.800, 0.850, 0.900, 0.950, 1.000 and 1.050%), six replicates of 20 birds each. The lysine levels did not influence (P>0.05) broiler performance in accumulated periods 28-35 days, 28-42 days and 28-49 days. There was no effect (P>0.05) of treatments on feed intake and feed conversion in the total periods (28-56 days). Effect was observed (P0.05) for carcass and breast weights of abdominal fat, thigh + drumstick, back, wing and fat deposition between the levels of lysine.(AU)

Realizou-se este estudo com o objetivo de avaliar níveis de lisina digestível para frangos tipo caipira, machos, de 28 a 56 dias de idade. Utilizou-se 720 frangos pescoço pelado de crescimento lento, da linhagem Label Rouge machos, distribuídos em delineamento inteiramente casualizado, composto por seis níveis de lisina digestível (0,800; 0,850; 0,900; 0,950; 1,000 e 1,050%), seis repetições, com 20 aves cada. Os níveis de lisina digestível não influenciaram (P>0,05) o desempenho dos frangos nos períodos acumulados de 28 a 35 dias, 28 a 42 dias e 28 a 49 dias. Não houve efeito (P>0,05) no consumo de ração e conversão alimentar no período total de criação (28-56 dias). Observou-se efeito (P0,05) para os rendimentos de carcaça e peito, pesos de gordura abdominal, coxa + sobrecoxa, dorso, asa e deposição de gordura entre os níveis de lisina digestível.(AU)ipt

Níveis de lisina digestível para frangos de corte tipo caipira de 28 a 56 dias de idade

The objective of this study was to evaluate digestible lysine levels for free-range broiler hillbilly, from 28 to 56 days old. We used 720 naked neck chickens slow-growing Label Rouge strain males, distributed in a completely randomized design with six digestible lysine levels (0.800, 0.850, 0.900, 0.950, 1.000 and 1.050%), six replicates of 20 birds each. The lysine levels did not influence (P>0.05) broiler performance in accumulated periods 28-35 days, 28-42 days and 28-49 days. There was no effect (P>0.05) of treatments on feed intake and feed conversion in the total periods (28-56 days). Effect was observed (P 0.05) of lysine levels on body weight at 35 days, final weight and weight gain from 28 to 56 days old. There were no differences (P>0.05) for carcass and breast weights of abdominal fat, thigh + drumstick, back, wing and fat deposition between the levels of lysine. The carcass weight and breast varied (P 0.05) quadratically depending on the levels of dietary lysine. Increased breast weight provided an increase of carcass weight, a fact explained by the increase (P 0.05) in protein deposition according to the level of lysine that can be considered an indication of improved efficiency of utilization of nutrients. It is concluded that the level of 0.910% meets the requirement of digestible lysine for broilers hillbilly type, from 28 to 56 of age.

Realizou-se este estudo com o objetivo de avaliar níveis de lisina digestível para frangos tipo caipira, machos, de 28 a 56 dias de idade. Utilizou-se 720 frangos pescoço pelado de crescimento lento, da linhagem Label Rouge machos, distribuídos em delineamento inteiramente casualizado, composto por seis níveis de lisina digestível (0,800; 0,850; 0,900; 0,950; 1,000 e 1,050%), seis repetições, com 20 aves cada. Os níveis de lisina digestível não influenciaram (P>0,05) o desempenho dos frangos nos períodos acumulados de 28 a 35 dias, 28 a 42 dias e 28 a 49 dias. Não houve efeito (P>0,05) no consumo de ração e conversão alimentar no período total de criação (28-56 dias). Observou-se efeito (P 0,05) dos níveis de lisina no peso aos 35 dias, peso final e ganho de peso dos 28 aos 56 dias de idade. Não foram observadas diferenças (P>0,05) para os rendimentos de carcaça e peito, pesos de gordura abdominal, coxa + sobrecoxa, dorso, asa e deposição de gordura entre os níveis de lisina digestível. Os pesos da carcaça e do peito variaram (P 0,05) de forma quadrática, em função dos níveis de lisina digestível. O aumento do peso do peito proporcionou aumento do peso da carcaça, fato explicado pelo aumento (P 0,05) na deposição de proteína em função dos níveis de lisina digestível que pode ser considerado um indicativo da melhora da eficiência de utilização dos nutrientes da dieta. Conclui-se que o nível de 0,910% lisina digestível atende a exigência de frangos de corte tipo caipira, de 28 a 56 das de idade.

Levels of digestible lysine for free-range broiler chickens from 28 to 56 days of age / Níveis de lisina digestível para frangos de corte tipo caipira de 28 a 56 dias de idade

The objective of this study was to evaluate digestible lysine levels for free-range broiler hillbilly, from 28 to 56 days old. We used 720 naked neck chickens slow-growing Label Rouge strain males, distributed in a completely randomized design with six digestible lysine levels (0.800, 0.850, 0.900, 0.950, 1.000 and 1.050%), six replicates of 20 birds each. The lysine levels did not influence (P>0.05) broiler performance in accumulated periods 28-35 days, 28-42 days and 28-49 days. There was no effect (P>0.05) of treatments on feed intake and feed conversion in the total periods (28-56 days). Effect was observed (P0.05) for carcass and breast weights of abdominal fat, thigh + drumstick, back, wing and fat deposition between the levels of lysine.

Realizou-se este estudo com o objetivo de avaliar níveis de lisina digestível para frangos tipo caipira, machos, de 28 a 56 dias de idade. Utilizou-se 720 frangos pescoço pelado de crescimento lento, da linhagem Label Rouge machos, distribuídos em delineamento inteiramente casualizado, composto por seis níveis de lisina digestível (0,800; 0,850; 0,900; 0,950; 1,000 e 1,050%), seis repetições, com 20 aves cada. Os níveis de lisina digestível não influenciaram (P>0,05) o desempenho dos frangos nos períodos acumulados de 28 a 35 dias, 28 a 42 dias e 28 a 49 dias. Não houve efeito (P>0,05) no consumo de ração e conversão alimentar no período total de criação (28-56 dias). Observou-se efeito (P0,05) para os rendimentos de carcaça e peito, pesos de gordura abdominal, coxa + sobrecoxa, dorso, asa e deposição de gordura entre os níveis de lisina digestível.ipt

Termorregulação e produção de ovos de galinhas Label Rouge em ambiente equatorial semiárido / Thermorregulation and egg production of Label Rouge hens in an equatorial semi-arid environment

Este estudo objetivou avaliar as diferenças regionais na temperatura superficial através de imagens térmicas e o efeito do ambiente semiárido e do tamanho da partícula do milho no desempenho, qualidade do ovo e perda de calor sensível de poedeiras do pescoço pelado. Em Mossoró-RN, 60 galinhas da linhagem Label Rouge em fase de postura foram distribuídas em um delineamento inteiramente casualizado, onde foram fornecidas rações com diferentes tamanhos da partícula do milho ou diâmetro geométrico médio (DGM) de 605 ?m, 1030 ?m e 2280 ?m. As variáveis ambientais foram aferidas no centro do galpão: temperatura do globo negro (TG) e do ar (TA), velocidade do vento (U) e umidade relativa (UR). A temperatura retal (TR), frequência respiratória (FR) e temperatura superficial (TS) foram aferidas em cada ave uma vez por semana. Para a perda de calor sensível, TR, FR e TS a análise de variância foi realizada pelo método dos quadrados mínimos e a comparação de médias para todas as veriáveis pelo teste de Tukey (p<0.05). Os resultados mostraram que o DGM igual a 2280 ?m aumentou o consumo de ração, causando elevação na temperatura corporal e frequência respiratória como resposta à maior produção de calor metabólico. As aves alimentadas com este mesmo DGM apresentaram qualidade da casca do ovo inferior. A transferência de calor sensível apresentou-se com um mecanismo de dissipação térmica, onde o aumento nos níveis de radiação e TA causaram diminuição significativa na perda de calor por radiação, mas a convecção foi elevada em alta TA devido ao aumento na movimentação do ar. Houve diferença regional na TS, onde as patas atuaram como janelas térmicas.

This study aimed to evaluate the effect of corn particle size on performance, egg quality and sensible heat loss, beyond of the regional differences in surface temperature of naked neck laying hens by infrared thermography. In Mossoró - RN, 60 label Rouge chickens in laying stage were distributed in a completely randomized design, where were fed with diets containing different corn particle size or geometric mean diameter ( GMD ) of 605 μm 1030 μm and 2280 μm . Environmental variables were measured in center of the shed: black globe temperature ( T G ) and air ( T A ), wind speed ( U ) and relative humidity ( R H ). Rectal temperature ( R T ), respiratory rate ( R R ) and surface temperature ( T S ) were measured in each bird once a week. For sensible heat loss, R T R R and T S the analysis of variance was performed by least squares method and comparison of means by Tukey's test (p<0.05). The results showed that the GMD 2280 μm increased the feed intake, causing e levation in body temperature and respiratory rate in response to increased metabolic heat production. The hens fed with this same GMD showed lower quality eggshell. The sensible heat transfer was, during the study, a heat dissipation mechanism, where the increase in radiation and T A levels caused significant decrease in heat loss by radiation, but heat loss by convection was high in high T A due to increased wind speed. There are regional differences in the T S where the legs act as thermal window.

Exigências de lisina digestível para aves de corte da linhagem ISA Label criadas em semiconfinamento / Digestible lysine requirements for ISA Label broilers reared in free-range system

Foram realizados três experimentos para determinar as exigências de lisina digestível para aves da linhagem ISA Label, de ambos os sexos, criadas em semiconfinamento durante as fases: inicial (1 a 28 dias), de crescimento (28 a 56 dias) e final (56 a 84 dias). Em cada experimento, foram utilizadas 480 aves, alojadas em 24 piquetes, cada um contendo abrigo coberto de 3,13m² e área de pastejo de 72,87m². O delineamento experimental utilizado foi o inteiramente ao acaso, em esquema fatorial 4x2 (níveis de lisina e sexo) com três repetições de 20 aves cada. Os níveis de lisina digestível avaliados foram: 0,850; 0,970; 1,090 e 1,210 por cento na fase inicial; 0,750; 0,870; 0,990 e 1,110 por cento na fase de crescimento e 0,640; 0,760; 0,880 e 1,000 por cento na fase final. Foram mensuradas as variáveis de desempenho, característica de carcaça, deposição de proteína e gordura corporal, peso e teor de proteína das penas. Com base nos resultados de desempenho, recomendam-se 1, 041; 1,006 e 0,760 por cento de lisina digestível em rações para aves ISA Label nas fases inicial, de crescimento e final, respectivamente.(AU)

Three assays were carried out to determine digestible lysine requirement for ISA Label, both genders, in free-range system on starter (1 to 28 days), growing (28 to 56 days) e finishing phases (56 to 84 days). A total of 480 birds were distributed into 24 pens, each one composed by shelter (3.13m²) and pasture (72.87m²). The experimental design was a completely randomized in factorial arrangement (four levels of lysine and two genders) with three replicates of 20 birds. The digestible lysine levels were 0.85, 0.97, 1.09, and 1.21 percent for starter; 0.75, 0.87, 0.99, and 1.11 percent for growing; and 0.64, 0.76, 0.88, and 1.00 percent for finishing phases. The analyzed parameters were performance, carcass yield, protein and fat deposition, weight, and protein in the feathers. Based on bird performance the estimated digestible lysine level, was 1.041, 1.006, and 0.760 percent for the starter, growing and finishing phases, respectively.(AU)

Exigências de lisina digestível para aves de corte da linhagem ISA Label criadas em semiconfinamento / Digestible lysine requirements for ISA Label broilers reared in free-range system

Foram realizados três experimentos para determinar as exigências de lisina digestível para aves da linhagem ISA Label, de ambos os sexos, criadas em semiconfinamento durante as fases: inicial (1 a 28 dias), de crescimento (28 a 56 dias) e final (56 a 84 dias). Em cada experimento, foram utilizadas 480 aves, alojadas em 24 piquetes, cada um contendo abrigo coberto de 3,13m² e área de pastejo de 72,87m². O delineamento experimental utilizado foi o inteiramente ao acaso, em esquema fatorial 4x2 (níveis de lisina e sexo) com três repetições de 20 aves cada. Os níveis de lisina digestível avaliados foram: 0,850; 0,970; 1,090 e 1,210 por cento na fase inicial; 0,750; 0,870; 0,990 e 1,110 por cento na fase de crescimento e 0,640; 0,760; 0,880 e 1,000 por cento na fase final. Foram mensuradas as variáveis de desempenho, característica de carcaça, deposição de proteína e gordura corporal, peso e teor de proteína das penas. Com base nos resultados de desempenho, recomendam-se 1, 041; 1,006 e 0,760 por cento de lisina digestível em rações para aves ISA Label nas fases inicial, de crescimento e final, respectivamente.

Three assays were carried out to determine digestible lysine requirement for ISA Label, both genders, in free-range system on starter (1 to 28 days), growing (28 to 56 days) e finishing phases (56 to 84 days). A total of 480 birds were distributed into 24 pens, each one composed by shelter (3.13m²) and pasture (72.87m²). The experimental design was a completely randomized in factorial arrangement (four levels of lysine and two genders) with three replicates of 20 birds. The digestible lysine levels were 0.85, 0.97, 1.09, and 1.21 percent for starter; 0.75, 0.87, 0.99, and 1.11 percent for growing; and 0.64, 0.76, 0.88, and 1.00 percent for finishing phases. The analyzed parameters were performance, carcass yield, protein and fat deposition, weight, and protein in the feathers. Based on bird performance the estimated digestible lysine level, was 1.041, 1.006, and 0.760 percent for the starter, growing and finishing phases, respectively.

Effect of heat exposure on the thermoregulatory responses of selected naked neck chickens / feito da exposição ao calor na resposta termorregulatória de aves de pescoço pelado selecionadas

The variation in cloacal temperature, body weight loss and expression of the 70 kDa heat shock protein (Hsp70) in three naked neck broiler genotypes during heat stress were studied. Twelve birds of each genotype (Na/Na, Na/na and na/na) were reared to market weight (approximately 2.1kg) at thermoneutral temperature. Six birds from each group served as controls and the remaining six underwent gradual heat stress (from 28oC to 36oC). Cloacal temperature and body weight were measured before and after exposure to heat. Liver samples were collected and Hsp70 levels were quantified using western blotting with monoclonal anti-chicken Hsp70 antibody. Heterozygous (Na/na) birds had a significantly lower cloacal temperature variation and less body weight loss during heat stress than the other genotypes. There was no significant difference in the Hsp70 levels among the genotypes. Heterozygous birds (Na/na) appeared to have a slight advantage over the other genotypes during gradual heat stress, perhaps because of a heterotic effect.(AU)

Estudaram-se o efeito do estresse térmico sobre a temperatura cloacal, a perda de peso corporal e a expressão da proteína de estresse de 70 kDa (Hsp70) em três genótipos de galinhas de pescoço-pelado. Foram usadas 12 aves de cada genótipo (Na/Na, Na/na e na/na), com peso corporal médio de 2,100kg e criadas em temperatura termoneutra. Seis aves de cada grupo serviram como controle e as seis restantes foram submetidas a estresse térmico gradativo (28oC 36oC). A temperatura cloacal e o peso das aves foram avaliados antes e depois do estresse. Amostras de fígado foram coletadas e os níveis de Hsp70 foram quantificados por "western blotting" com anticorpo monoclonal específico para Hsp70 de galinha. As aves heterozigotas (Na/na) tiveram variação de temperatura cloacal significativamente menor e menor perda de peso corporal durante o estresse térmico do que as dos outros genótipos. Não foi observada diferença significativa (P>0,05) para o aumento de Hsp70 no fígado. Aves heterozigotas parecem ter pequena vantagem sobre os outros genótipos durante estresse térmico gradativo, talvez devido ao efeito de heterose.(AU)

Resistência ao Estresse Calórico em Frangos de Corte de Pescoço Pelado

Birds of two lineages, a carrier of the Naked Neck gene (Na_) that determines reduction in the feathering and other non-carrier (normal feathering, nana), were submitted to thermal stress (38, 40 and 42ºC) in climatic chambers at 28, 35 and 42 days of age to verify the resistance to the thermal stress. Significant differences were verified among the mean rectal temperature of the normal feathered lineage when compared with the naked neck lineage, in all the ages and stress periods, with higher values in the normal feathered birds. The same result was found for mean respiratory rate. Significant difference was found for weight loss between the two lineages only at the age of 35 days. The results obtained suggest that the Naked Neck lineage possesses higher resistance to the thermal stress in relation to the normal feathered lineage.

Aves de duas linhagens, sendo uma portadora do gene pescoço pelado (Na_) que determina redução no empenamento, e outra não portadora, com empenamento normal (nana), foram submetidas a estresse térmico gradativo (38, 40 e 42ºC), em câmara climática, nas idades de 28, 35 e 42 dias, com o intuito de se verificar a resistência ao estresse térmico. Foram verificadas diferenças significativas entre a temperatura retal média e a taxa respiratória média da linhagem de empenamento normal quando comparada com a linhagem de pescoço pelado, em todas as idades e períodos de estresse. Foram verificados valores mais altos das aves de empenamento normal, demonstrando a influência do conjunto temperatura de estresse térmico e idade. Pôde-se constatar que houve diferença significativa entre as linhagens para as médias de perda de peso apenas aos 35 dias de idade. Os resultados obtidos sugerem que a linhagem de pescoço pelado (Na_) possui maior resistência ao estresse térmico em relação à linhagem de empenamento normal (nana).

Resistência ao Estresse Calórico em Frangos de Corte de Pescoço Pelado

Birds of two lineages, a carrier of the Naked Neck gene (Na_) that determines reduction in the feathering and other non-carrier (normal feathering, nana), were submitted to thermal stress (38, 40 and 42ºC) in climatic chambers at 28, 35 and 42 days of age to verify the resistance to the thermal stress. Significant differences were verified among the mean rectal temperature of the normal feathered lineage when compared with the naked neck lineage, in all the ages and stress periods, with higher values in the normal feathered birds. The same result was found for mean respiratory rate. Significant difference was found for weight loss between the two lineages only at the age of 35 days. The results obtained suggest that the Naked Neck lineage possesses higher resistance to the thermal stress in relation to the normal feathered lineage.

Aves de duas linhagens, sendo uma portadora do gene pescoço pelado (Na_) que determina redução no empenamento, e outra não portadora, com empenamento normal (nana), foram submetidas a estresse térmico gradativo (38, 40 e 42ºC), em câmara climática, nas idades de 28, 35 e 42 dias, com o intuito de se verificar a resistência ao estresse térmico. Foram verificadas diferenças significativas entre a temperatura retal média e a taxa respiratória média da linhagem de empenamento normal quando comparada com a linhagem de pescoço pelado, em todas as idades e períodos de estresse. Foram verificados valores mais altos das aves de empenamento normal, demonstrando a influência do conjunto temperatura de estresse térmico e idade. Pôde-se constatar que houve diferença significativa entre as linhagens para as médias de perda de peso apenas aos 35 dias de idade. Os resultados obtidos sugerem que a linhagem de pescoço pelado (Na_) possui maior resistência ao estresse térmico em relação à linhagem de empenamento normal (nana).