Effect of cypermethrin on the control of lesser mealworm (Alphitobius diaperinus) and broiler performance

ABSTRACT: This study analysed the effectiveness of using different levels of a product based on 6% cypermethrin and 2% citronella on broiler production and control the lesser mealworm (Alphitobius diaperinus). A total of 648 one-day-old chicks (Cobb®) which were allocated to one of three treatments (no application of the commercial product - control, and two concentrations of the product 2.00 and 3.33g/m2) in eight replicates with 27 birds each. The commercial product, which was based on cypermethrin was applied in the chambers with an atomizer. The lesser mealworm population was sampled weekly (1, 7, 14, 21, 28, 35 and 42 days of the experiment) using traps, at three points (front, middle and back) inside the pen. The performance, carcass and cut yields were evaluated. At 21, 28, 35 and 42 days of the experiment, the number of lesser mealworm adults and larvae was lower in the treatment groups involving 2.00 and 3.33g/m2 of the product than in the control group. On the first and 14th days of the study, the number of lesser mealworms adults was lower in the group treated with 3.33g/m2 of the product compared to the control group, although the results did not differ statistically from those obtained with 2.00g/m2 of the product. In conclusion, the application of the commercial product at both concentrations (2.00 and 3.33g/m2) was effective in combating Alphitobius diaperinus adults and larvae, and the performance was not influenced by treatments.

RESUMO: Este estudo analisou a eficácia do uso de diferentes níveis de um produto à base de cipermetrina a 6% e citronela a 2%, na produção de frangos de corte e no controle do cascudinho (Alphitobius diaperinus). Um total de 648 pintos de um dia de idade (Cobb®) foram distribuídos em três câmaras com os tratamentos (sem aplicação do produto comercial - controle, e duas concentrações do produto comercial - 2,00 e 3,33g/m2) em oito repetições com 27 aves cada. O produto comercial a base de cipermetrina foi aplicado nas câmaras com um atomizador. A população de cascudinho foi amostrada semanalmente (1, 7, 14, 21, 28, 35 e 42 dias do experimento) usando armadilhas, em três pontos (frente, meio e fundo) de cada parcela. Foram avaliados o desempenho, rendimentos de carcaça e cortes. Aos 21, 28, 35 e 42 dias do experimento, o número de adultos e larvas de cascudinho foi menor nos grupos de tratamento envolvendo 2,00 e 3,33g/m2 do produto quando comparado ao grupo controle. No primeiro e no 14º dia do estudo, o número de cascudinhos adultos foi menor no grupo tratado com 3,33g/m2 do produto em comparação ao grupo controle, embora os resultados não tenham diferido estatisticamente daqueles obtidos com 2,00g/m2 do produto. A conversão alimentar de 1 a 21 dias de idade foi significativa, com os melhores resultados para essa variável quando aplicado 3,33g do produto por metro quadrado e no tratamento controle. Em conclusão, a aplicação do produto comercial em ambas as concentrações (2,00 e 3,33g/m2) foi eficaz no combate a adultos e larvas de Alphitobius diaperinus e, não influenciou o desempenho.

Effect of cypermethrin on the control of lesser mealworm (Alphitobius diaperinus) and broiler performance / Efeito da cipermetrina no controle de cascudinho (Alphitobius diaperinus) sobre o desempenho de frangos de corte

This study analysed the effectiveness of using different levels of a product based on 6% cypermethrin and 2% citronella on broiler production and control the lesser mealworm (Alphitobius diaperinus). A total of 648 one-day-old chicks (Cobb®) which were allocated to one of three treatments (no application of the commercial product - control, and two concentrations of the product 2.00 and 3.33g/m2) in eight replicates with 27 birds each. The commercial product, which was based on cypermethrin was applied in the chambers with an atomizer. The lesser mealworm population was sampled weekly (1, 7, 14, 21, 28, 35 and 42 days of the experiment) using traps, at three points (front, middle and back) inside the pen. The performance, carcass and cut yields were evaluated. At 21, 28, 35 and 42 days of the experiment, the number of lesser mealworm adults and larvae was lower in the treatment groups involving 2.00 and 3.33g/m2 of the product than in the control group. On the first and 14th days of the study, the number of lesser mealworms adults was lower in the group treated with 3.33g/m2 of the product compared to the control group, although the results did not differ statistically from those obtained with 2.00g/m2 of the product. In conclusion, the application of the commercial product at both concentrations (2.00 and 3.33g/m2) was effective in combating Alphitobius diaperinus adults and larvae, and the performance was not influenced by treatments.(AU)

Este estudo analisou a eficácia do uso de diferentes níveis de um produto à base de cipermetrina a 6% e citronela a 2%, na produção de frangos de corte e no controle do cascudinho (Alphitobius diaperinus). Um total de 648 pintos de um dia de idade (Cobb®) foram distribuídos em três câmaras com os tratamentos (sem aplicação do produto comercial - controle, e duas concentrações do produto comercial - 2,00 e 3,33g/m2) em oito repetições com 27 aves cada. O produto comercial a base de cipermetrina foi aplicado nas câmaras com um atomizador. A população de cascudinho foi amostrada semanalmente (1, 7, 14, 21, 28, 35 e 42 dias do experimento) usando armadilhas, em três pontos (frente, meio e fundo) de cada parcela. Foram avaliados o desempenho, rendimentos de carcaça e cortes. Aos 21, 28, 35 e 42 dias do experimento, o número de adultos e larvas de cascudinho foi menor nos grupos de tratamento envolvendo 2,00 e 3,33g/m2 do produto quando comparado ao grupo controle. No primeiro e no 14º dia do estudo, o número de cascudinhos adultos foi menor no grupo tratado com 3,33g/m2 do produto em comparação ao grupo controle, embora os resultados não tenham diferido estatisticamente daqueles obtidos com 2,00g/m2 do produto. A conversão alimentar de 1 a 21 dias de idade foi significativa, com os melhores resultados para essa variável quando aplicado 3,33g do produto por metro quadrado e no tratamento controle. Em conclusão, a aplicação do produto comercial em ambas as concentrações (2,00 e 3,33g/m2) foi eficaz no combate a adultos e larvas de Alphitobius diaperinus e, não influenciou o desempenho.(AU)

Effect of cypermethrin on the control of lesser mealworm (Alphitobius diaperinus) and broiler performance / Efeito da cipermetrina no controle de cascudinho (Alphitobius diaperinus) sobre o desempenho de frangos de corte

This study analysed the effectiveness of using different levels of a product based on 6% cypermethrin and 2% citronella on broiler production and control the lesser mealworm (Alphitobius diaperinus). A total of 648 one-day-old chicks (Cobb®) which were allocated to one of three treatments (no application of the commercial product - control, and two concentrations of the product 2.00 and 3.33g/m2) in eight replicates with 27 birds each. The commercial product, which was based on cypermethrin was applied in the chambers with an atomizer. The lesser mealworm population was sampled weekly (1, 7, 14, 21, 28, 35 and 42 days of the experiment) using traps, at three points (front, middle and back) inside the pen. The performance, carcass and cut yields were evaluated. At 21, 28, 35 and 42 days of the experiment, the number of lesser mealworm adults and larvae was lower in the treatment groups involving 2.00 and 3.33g/m2 of the product than in the control group. On the first and 14th days of the study, the number of lesser mealworms adults was lower in the group treated with 3.33g/m2 of the product compared to the control group, although the results did not differ statistically from those obtained with 2.00g/m2 of the product. In conclusion, the application of the commercial product at both concentrations (2.00 and 3.33g/m2) was effective in combating Alphitobius diaperinus adults and larvae, and the performance was not influenced by treatments.(AU)

Este estudo analisou a eficácia do uso de diferentes níveis de um produto à base de cipermetrina a 6% e citronela a 2%, na produção de frangos de corte e no controle do cascudinho (Alphitobius diaperinus). Um total de 648 pintos de um dia de idade (Cobb®) foram distribuídos em três câmaras com os tratamentos (sem aplicação do produto comercial - controle, e duas concentrações do produto comercial - 2,00 e 3,33g/m2) em oito repetições com 27 aves cada. O produto comercial a base de cipermetrina foi aplicado nas câmaras com um atomizador. A população de cascudinho foi amostrada semanalmente (1, 7, 14, 21, 28, 35 e 42 dias do experimento) usando armadilhas, em três pontos (frente, meio e fundo) de cada parcela. Foram avaliados o desempenho, rendimentos de carcaça e cortes. Aos 21, 28, 35 e 42 dias do experimento, o número de adultos e larvas de cascudinho foi menor nos grupos de tratamento envolvendo 2,00 e 3,33g/m2 do produto quando comparado ao grupo controle. No primeiro e no 14º dia do estudo, o número de cascudinhos adultos foi menor no grupo tratado com 3,33g/m2 do produto em comparação ao grupo controle, embora os resultados não tenham diferido estatisticamente daqueles obtidos com 2,00g/m2 do produto. A conversão alimentar de 1 a 21 dias de idade foi significativa, com os melhores resultados para essa variável quando aplicado 3,33g do produto por metro quadrado e no tratamento controle. Em conclusão, a aplicação do produto comercial em ambas as concentrações (2,00 e 3,33g/m2) foi eficaz no combate a adultos e larvas de Alphitobius diaperinus e, não influenciou o desempenho.(AU)

The Effect of Dietary Garlic (Allium Sativum), Black Cumin (Nigella Sativa) and Their Combination on Performance, Intestine Morphometry, Serum Biochemistry and Antioxidant Status of Broiler Chickens

This study was conducted to examine the effects of garlic (G), black cumin (BC) and G+BC within the broiler rations, on performance, relative organ weights, intestinal morphology, serum biochemistry and plasma total oxidant/ antioxidant status. Two hundred broilers chicks (Ross 308) were used and they were divided into 4 groups consisting of 5 subgroups of 10 animals each. The trial was ended on the 35th day. No addition was made to the control group ration. 5g / kg garlic (G), 5g / kg black cumin (BC) and 5g / kg G + 5g / kg BC were added to the experimental group rations, respectively. There was no statistical difference among the trial groups in terms of BWG, FI, FCR and relative organ weights (p>0.05). Serum total protein (p 0.05) and albumin (p 0.001) levels were higher in BC and BC +G groups as compared to G and control group. Serum AST activity were lower in G group as compared to control and other experimental groups (p 0.05). On histological examinations, regarding the duodenal epithelium; there was no difference among the trial groups. Hyperemia was observed, especially in the G group, in macroscopic exams of lamina propria and other viticular areas. The lymph follicles were more wide spread in the G + BC, G and BC groups than in the control. The results of the study showed that the combination of BC and G can have beneficial effects, and different doses of G and BC may be used to see positive or negative effects.(AU)

The Effect of Dietary Garlic (Allium Sativum), Black Cumin (Nigella Sativa) and Their Combination on Performance, Intestine Morphometry, Serum Biochemistry and Antioxidant Status of Broiler Chickens

This study was conducted to examine the effects of garlic (G), black cumin (BC) and G+BC within the broiler rations, on performance, relative organ weights, intestinal morphology, serum biochemistry and plasma total oxidant/ antioxidant status. Two hundred broilers chicks (Ross 308) were used and they were divided into 4 groups consisting of 5 subgroups of 10 animals each. The trial was ended on the 35th day. No addition was made to the control group ration. 5g / kg garlic (G), 5g / kg black cumin (BC) and 5g / kg G + 5g / kg BC were added to the experimental group rations, respectively. There was no statistical difference among the trial groups in terms of BWG, FI, FCR and relative organ weights (p>0.05). Serum total protein (p 0.05) and albumin (p 0.001) levels were higher in BC and BC +G groups as compared to G and control group. Serum AST activity were lower in G group as compared to control and other experimental groups (p 0.05). On histological examinations, regarding the duodenal epithelium; there was no difference among the trial groups. Hyperemia was observed, especially in the G group, in macroscopic exams of lamina propria and other viticular areas. The lymph follicles were more wide spread in the G + BC, G and BC groups than in the control. The results of the study showed that the combination of BC and G can have beneficial effects, and different doses of G and BC may be used to see positive or negative effects.

Effect of two chemotypes of oregano essential oil on broiler performance, nutrient balance, and lipid peroxidation of breast meat during storage / Efeito de dois quimiotipos de óleo essencial de orégano no desempenho do frango, equilíbrio de nutrientes e peroxidação lipídica da carne de peito durante o armazenamento

This study evaluated the functional effects of two chemotypes of oregano essential oil (OEO): Lippia Origanoides (LO) and a comercial product Synergy Essence (SE). Broilers were randomly assigned to one of eight dietary treatments: 1) Basal diet (BD); 2) BD+ antibiotic growth promoters (AGP) (bacitracin 50g/ton); 3) BD+LO125 (125g/ton); 4) BD+LO250 (250g/ton); 5) BD+LO500 (500g/ton); 6) BD+SE125 (125g/ton); 7) BD+SE250 (250g/ton); 8) BD+SE500 (500g/ton). At the time of slaughter (42 d), five birds per treatment were slaughtered. A portion of the breast was minced and stored at -4 ºC for 3, 6, and 9 days. Lipid peroxidation was determined by measuring of malondialdehyde (MDA), data were analyzed as a completely randomized design with a factorial arrangement of treatments (8x4). Broilers fed SE250 had greater average daily gain (ADG) compared to broilers fed BD (P<0.05). Broilers fed LO500 had greater (P<0.05) organic matter digestibility than the ones fed BD. As days of storage increased, MDA concentration increased (P<0.05). Broilers fed SE500 had lower (P<0.05) MDA concentration than those fed BD and AGP. These data indicate that birds fed OEO grow faster than those fed a BD, similar to birds fed AGP. Some of these responses are possibly explained by increased digestibility and energy utilization. In addition, providing OEO from SE at 500g/ton resulted in lower lipid peroxidation in ground breast meat throughout the tested storage time.

Este estudo avaliou os efeitos funcionais de dois quimiótipos de óleo esencial de orégano (OEO): Lippia Origanoides (LO) e um produto comercial Synergy Essence (SE). Os frangos de corte foram distribuídos aleatoriamente para um dos oito tratamentos dietéticos: 1) Dieta basal (BD); 2) BD + antibiótico promotor de crescimento (AGP) (bacitracina 50 g/tonelada); 3) BD + LO125 (125 g/tonelada); 4) BD + LO250 (250 g/tonelada); 5) BD + LO500 (500 g/tonelada); 6) BD + SE125 (125 g/tonelada); 7) BD + SE250 (250 g/tonelada); 8) BD + SE500 (500g/tonelada). No momento do abate (42 d), cinco aves por tratamento foram abatidas. Uma porção do peito foi picada e armazenada a -4 ºC durante 3, 6 e 9 dias. A peroxidação lipídica foi determinada pela medição de malondialdeído (MDA), os dados foram analisados ​​como um delineamento inteiramente casualizado com um arranjo fatorial de tratamentos (8x4). Os frangos alimentados com SE250 apresentaram maior ganho diário médio (ADG) em comparação com o BD (P <0,05). Os frangos alimentados com LO500 apresentaram maior digestibilidade da matéria orgânica (P <0,05) do que BD. À medida que o dia do armazenamento aumentou, a concentração de MDA aumentou (P <0,05) Os frangos de corte alimentados com SE500 apresentaram menor concentração de MDA (BD <0,05) do que BD e AGP. Esses dados indicam que as aves alimentadas com OEO crescem mais rápido do que aquelas alimentadas com BD e semelhantes às aves alimentadas com AGP, com algumas dessas respostas sendo possivelmente explicadas pelo aumento da digestibilidade e da utilização de energia, além de fornecer OEO do SE a 500g/ton, frangos de corte resulta em menor Peroxidação lipídica na carne de peito moída ao longo do tempo de armazenamento testado.

Effect of two chemotypes of oregano essential oil on broiler performance, nutrient balance, and lipid peroxidation of breast meat during storage / Efeito de dois quimiotipos de óleo essencial de orégano no desempenho do frango, equilíbrio de nutrientes e peroxidação lipídica da carne de peito durante o armazenamento

This study evaluated the functional effects of two chemotypes of oregano essential oil (OEO): Lippia Origanoides (LO) and a comercial product Synergy Essence (SE). Broilers were randomly assigned to one of eight dietary treatments: 1) Basal diet (BD); 2) BD+ antibiotic growth promoters (AGP) (bacitracin 50g/ton); 3) BD+LO125 (125g/ton); 4) BD+LO250 (250g/ton); 5) BD+LO500 (500g/ton); 6) BD+SE125 (125g/ton); 7) BD+SE250 (250g/ton); 8) BD+SE500 (500g/ton). At the time of slaughter (42 d), five birds per treatment were slaughtered. A portion of the breast was minced and stored at -4 ºC for 3, 6, and 9 days. Lipid peroxidation was determined by measuring of malondialdehyde (MDA), data were analyzed as a completely randomized design with a factorial arrangement of treatments (8x4). Broilers fed SE250 had greater average daily gain (ADG) compared to broilers fed BD (P<0.05). Broilers fed LO500 had greater (P<0.05) organic matter digestibility than the ones fed BD. As days of storage increased, MDA concentration increased (P<0.05). Broilers fed SE500 had lower (P<0.05) MDA concentration than those fed BD and AGP. These data indicate that birds fed OEO grow faster than those fed a BD, similar to birds fed AGP. Some of these responses are possibly explained by increased digestibility and energy utilization. In addition, providing OEO from SE at 500g/ton resulted in lower lipid peroxidation in ground breast meat throughout the tested storage time.(AU)

Este estudo avaliou os efeitos funcionais de dois quimiótipos de óleo esencial de orégano (OEO): Lippia Origanoides (LO) e um produto comercial Synergy Essence (SE). Os frangos de corte foram distribuídos aleatoriamente para um dos oito tratamentos dietéticos: 1) Dieta basal (BD); 2) BD + antibiótico promotor de crescimento (AGP) (bacitracina 50 g/tonelada); 3) BD + LO125 (125 g/tonelada); 4) BD + LO250 (250 g/tonelada); 5) BD + LO500 (500 g/tonelada); 6) BD + SE125 (125 g/tonelada); 7) BD + SE250 (250 g/tonelada); 8) BD + SE500 (500g/tonelada). No momento do abate (42 d), cinco aves por tratamento foram abatidas. Uma porção do peito foi picada e armazenada a -4 ºC durante 3, 6 e 9 dias. A peroxidação lipídica foi determinada pela medição de malondialdeído (MDA), os dados foram analisados ​​como um delineamento inteiramente casualizado com um arranjo fatorial de tratamentos (8x4). Os frangos alimentados com SE250 apresentaram maior ganho diário médio (ADG) em comparação com o BD (P <0,05). Os frangos alimentados com LO500 apresentaram maior digestibilidade da matéria orgânica (P <0,05) do que BD. À medida que o dia do armazenamento aumentou, a concentração de MDA aumentou (P <0,05) Os frangos de corte alimentados com SE500 apresentaram menor concentração de MDA (BD <0,05) do que BD e AGP. Esses dados indicam que as aves alimentadas com OEO crescem mais rápido do que aquelas alimentadas com BD e semelhantes às aves alimentadas com AGP, com algumas dessas respostas sendo possivelmente explicadas pelo aumento da digestibilidade e da utilização de energia, além de fornecer OEO do SE a 500g/ton, frangos de corte resulta em menor Peroxidação lipídica na carne de peito moída ao longo do tempo de armazenamento testado.(AU)

Effect of Vitamin E Supplementation and High Stocking Density on the Performance and Stress Parameters of Broilers

The present study was carried out to investigate the effect of dietary supplementation with vitamin E and stocking density on the mortality, body weight gain, feed conversion ratio, European production efficiency factor, heterophil/lymphocyte (H/L) ratio and liver glutathione (GSH) and malondialdehyde (MDA) levels of broilers. In total, 570 one-day-old Vencobb 400 broiler chickens were randomly assigned to three treatments, with six replicates each. G1 served as normal control and birds were provided a normal floor space (0.0465 m2/bird from day 1 to 21 and 0.0929 m2/bird from day 22 to 42) and basal diet containing vitamin E at 70 g/ton feed (n=150). G2 and G3 birds were subjected to high stocking density (0.0279 m2/bird from day 1 to 21 and 0.0557 m2/bird from day 22 to 42). G2 served as the high stocking density (HSD) control, birds were offered a basal diet with no vitamin E (n=210), whereas G3 birds were fed a basal diet containing vitamin E at 70 g/ton feed (n=210). The birds were fed with feed and water ad libitum throughout the study period. The supplementation of vitamin E to the birds subjected to HSD had a positive effect on body weight gain, feed conversion ratio (FCR), European Production Efficiency Factor (EPEF), H/L ratio, and liver GSH and MDA levels with those subjected to HSD and not supplemented with vitamin E. The results of the present study indicate that the supplementation of vitamin E at 70g/ton of feed to broilers subjected to HSD could effectively reverse the negative effects of HSD, and improve broiler performance.(AU)

Effect of Vitamin E Supplementation and High Stocking Density on the Performance and Stress Parameters of Broilers

The present study was carried out to investigate the effect of dietary supplementation with vitamin E and stocking density on the mortality, body weight gain, feed conversion ratio, European production efficiency factor, heterophil/lymphocyte (H/L) ratio and liver glutathione (GSH) and malondialdehyde (MDA) levels of broilers. In total, 570 one-day-old Vencobb 400 broiler chickens were randomly assigned to three treatments, with six replicates each. G1 served as normal control and birds were provided a normal floor space (0.0465 m2/bird from day 1 to 21 and 0.0929 m2/bird from day 22 to 42) and basal diet containing vitamin E at 70 g/ton feed (n=150). G2 and G3 birds were subjected to high stocking density (0.0279 m2/bird from day 1 to 21 and 0.0557 m2/bird from day 22 to 42). G2 served as the high stocking density (HSD) control, birds were offered a basal diet with no vitamin E (n=210), whereas G3 birds were fed a basal diet containing vitamin E at 70 g/ton feed (n=210). The birds were fed with feed and water ad libitum throughout the study period. The supplementation of vitamin E to the birds subjected to HSD had a positive effect on body weight gain, feed conversion ratio (FCR), European Production Efficiency Factor (EPEF), H/L ratio, and liver GSH and MDA levels with those subjected to HSD and not supplemented with vitamin E. The results of the present study indicate that the supplementation of vitamin E at 70g/ton of feed to broilers subjected to HSD could effectively reverse the negative effects of HSD, and improve broiler performance.

Effects of the Dietary Inclusion of a Probiotic, a Prebiotic or their Combinations on the Growth Performance of Broiler Chickens

ABSTRACT A total of 350-one-day old chicks were placed in 70 cages, with 14 cages per treatment. The following five treatment diets were fed for 14 days: T1 = non-supplemented, control diet (CONT); T2 = diet with antimicrobial growth promoter (AGP); T3 = diet with a probiotic (PROB); T4 = diet with a prebiotic(PREB), and T5 = diet with the probiotic and the prebiotic (SYM). The growth experiment was carried out from 1 to 14 days of age. Feed and water were provided ad libitum and birds were maintained at 24-h light schedule. Diets were formulated to contain 3000 kcalME/kg and 21.5% crude protein, and the test materials were added on top. The cumulative results of1 to 14 days of age revealed that broiler fed the AGP and PREB diets presented the highest BWG (305.5 and 297.3 g, respectively), while those fed the CONT diet had the lowest BWG (273.2 g) (p 0.05). On the other hand, the best FCR was obtained in broilers AGP and PROB (1.296 and 1.299 g:g, respectively), while chicks on the CONT and SYM diet had the worst FCR (1.423 and 1.372 g:g, respectively) (p 0.01). The results showed broilers fed the non-supplemented diet consistently presented poor performance. It was concluded that PROB or PREB can serve as alternatives to antibiotic in broiler starter feeds, with no performance impairment.

Effects of the Dietary Inclusion of a Probiotic, a Prebiotic or their Combinations on the Growth Performance of Broiler Chickens

A total of 350-one-day old chicks were placed in 70 cages, with 14 cages per treatment. The following five treatment diets were fed for 14 days: T1 = non-supplemented, control diet (CONT); T2 = diet with antimicrobial growth promoter (AGP); T3 = diet with a probiotic (PROB); T4 = diet with a prebiotic(PREB), and T5 = diet with the probiotic and the prebiotic (SYM). The growth experiment was carried out from 1 to 14 days of age. Feed and water were provided ad libitum and birds were maintained at 24-h light schedule. Diets were formulated to contain 3000 kcalME/kg and 21.5% crude protein, and the test materials were added on top. The cumulative results of1 to 14 days of age revealed that broiler fed the AGP and PREB diets presented the highest BWG (305.5 and 297.3 g, respectively), while those fed the CONT diet had the lowest BWG (273.2 g) (p<0.05). On the other hand, the best FCR was obtained in broilers AGP and PROB (1.296 and 1.299 g:g, respectively), while chicks on the CONT and SYM diet had the worst FCR (1.423 and 1.372 g:g, respectively) (p<0.01). The results showed broilers fed the non-supplemented diet consistently presented poor performance. It was concluded that PROB or PREB can serve as alternatives to antibiotic in broiler starter feeds, with no performance impairment.

Effects of the Dietary Inclusion of a Probiotic, a Prebiotic or their Combinations on the Growth Performance of Broiler Chickens

A total of 350-one-day old chicks were placed in 70 cages, with 14 cages per treatment. The following five treatment diets were fed for 14 days: T1 = non-supplemented, control diet (CONT); T2 = diet with antimicrobial growth promoter (AGP); T3 = diet with a probiotic (PROB); T4 = diet with a prebiotic(PREB), and T5 = diet with the probiotic and the prebiotic (SYM). The growth experiment was carried out from 1 to 14 days of age. Feed and water were provided ad libitum and birds were maintained at 24-h light schedule. Diets were formulated to contain 3000 kcalME/kg and 21.5% crude protein, and the test materials were added on top. The cumulative results of1 to 14 days of age revealed that broiler fed the AGP and PREB diets presented the highest BWG (305.5 and 297.3 g, respectively), while those fed the CONT diet had the lowest BWG (273.2 g) (p<0.05). On the other hand, the best FCR was obtained in broilers AGP and PROB (1.296 and 1.299 g:g, respectively), while chicks on the CONT and SYM diet had the worst FCR (1.423 and 1.372 g:g, respectively) (p<0.01). The results showed broilers fed the non-supplemented diet consistently presented poor performance. It was concluded that PROB or PREB can serve as alternatives to antibiotic in broiler starter feeds, with no performance impairment.(AU)

Effects of the Dietary Inclusion of a Probiotic, a Prebiotic or their Combinations on the Growth Performance of Broiler Chickens

ABSTRACT A total of 350-one-day old chicks were placed in 70 cages, with 14 cages per treatment. The following five treatment diets were fed for 14 days: T1 = non-supplemented, control diet (CONT); T2 = diet with antimicrobial growth promoter (AGP); T3 = diet with a probiotic (PROB); T4 = diet with a prebiotic(PREB), and T5 = diet with the probiotic and the prebiotic (SYM). The growth experiment was carried out from 1 to 14 days of age. Feed and water were provided ad libitum and birds were maintained at 24-h light schedule. Diets were formulated to contain 3000 kcalME/kg and 21.5% crude protein, and the test materials were added on top. The cumulative results of1 to 14 days of age revealed that broiler fed the AGP and PREB diets presented the highest BWG (305.5 and 297.3 g, respectively), while those fed the CONT diet had the lowest BWG (273.2 g) (p 0.05). On the other hand, the best FCR was obtained in broilers AGP and PROB (1.296 and 1.299 g:g, respectively), while chicks on the CONT and SYM diet had the worst FCR (1.423 and 1.372 g:g, respectively) (p 0.01). The results showed broilers fed the non-supplemented diet consistently presented poor performance. It was concluded that PROB or PREB can serve as alternatives to antibiotic in broiler starter feeds, with no performance impairment.

IMPACTO DA QUALIDADE DO PÉLETE DA RAÇÃO NO DESEMPENHO DE FRANGOS DE CORTE

A produção de ração na indústria avícola, em nível mundial, sempre enfrentou grandes desafios, motivando, assim, o desenvolvimento de pesquisas visando melhorar as características físicas e químicas do alimento fornecido às aves e, em consequência, seu desempenho. A fábrica de ração é considerada o fator mais importante dentro da cadeia avícola, pois 70% dos custos totais de produção são atribuídos ao alimento. Assim, e necessário desenvolver e instaurar técnicas de produção que garantam melhor disponibilidade e homogeneidade de nutrientes na ração, possibilitando a sua utilização eficiente por parte das aves. Objetivou-se avaliar o impacto do índice de durabilidade do pelete (PDI) e a dureza da ração, no desempenho zootécnico e outros fatores dos frangos de corte, por meio de uma revisão sistemática. Foram pesquisadas, em bases de dados, as publicações científicas do efeito do PDI e da dureza sobre o desempenho e outros fatores dos frangos de corte. O estudo foi feito, a partir de 30 artigos selecionados das bases de dados do portal de periódicos CAPES: Isi Web of Science, PubMed, Science Direct, Scielo e Scopus. O espaço de tempo analisado foi de 15 anos (2004 até 2019). Totalizou-se 16.446 frangos de corte com idades em dias de 1-21, 7-21, 22-42, 14-21, 1-42, e de 25-42. Os aspectos com mais representação foram os índices de desempenho zootécnico (consumo de ração (CR), ganho de peso (GP), conversão alimentar (CA) e energia metabolizável (EM) da dieta). Energia metabolizável (EM), energia metabolizável corrigida por nitrogênio (EMn), coeficiente de digestibilidade ileal de matéria seca (CDIMS), coeficiente de digestibilidade ileal aparente de matéria seca (CDIA), coeficiente de digestibilidade ileal de aminoácidos (CDIAA), rendimento de peito, peso do proventrículo, da moela e do pâncreas, pH do proventrículo e da moela, gelatinização do amido, microbiota cecal e produtividade da fábrica. Os dados foram ajustados ao modelo estatístico linear de Pearson (r) (p<0,05; p<0,01 e p<0,001), com a finalidade de medir o grau de correlação entre as variáveis. Para PDI de 14-21 dias e para o CR foi 0,75 (p<0,05), GP de 0,60 (p<0,05) e CA de 0,29 (p<0,05), considerada baixa embora significativa. Para CR de 22-42 foi de -0,67 (p<0,05) e para GP de 0.63 (p<0,05). Para EMn de 1-21 foi de -0,99 (p<0.01), e isso se deve a que, neste período o TGI apresenta muita imaturidade tendo um efeito altamente negativo. Para o CDIAA de 7-21 correlação foi de 0.90 (p<0.01). Nesta fase os frangos apresentam um maior aproveitamento dos nutrientes por efeito da cinética da digestão e de absorção dos nutrientes, fomentando a quebra dos aminoácidos. Para gelatinização de 21-42 foi 0,96 (p<0.01), sendo uma resposta positiva pois a temperatura de peletização é diretamente proporcional à qualidade do pelete, com aumento da temperatura pode se conseguir melhores respostas na gelatinização do amido. Para a dureza e CR de 14-21 e 22-42 foi de 0.62 (p<0,05) e 0.74 (p<0,01), embora de 7-21 a correlação foi negativa -0,66 (p<0,01). Para GP 14-21 e de 22 a 42 foi de 0,55 e 0,78 (p<0.05 e p<0.01). De 7-21 foi negativa significativa de -0,87 (p<0.01), sendo uma consequência do processo adaptativo lento do TGI. Para CA de 22-42 foi -0,86 (p<0.001). Para EM de 1-21 e 7-1 de 0,90 e 0,94 (p<0.001), respectivamente. CDIA e CDIAA de 1-2 foi de 0,68 (p<0.01), os frangos apresentaram uma diminuição na seletividade de ração levando a poupar mais energia durante essa fase de crescimento. Para gelatinização de 1-21 foi de 0,70 (p<0.01), sendo uma resposta positiva pois uma maior temperatura leva a um aumento na tensão superficial dos peletes aumentando a sua dureza. O PDI e a dureza da ração têm impacto positivo ou negativo no desempenho e em outros fatores fisiológicos dos frangos de corte, tendo em conta aspectos como os benefícios ao nível de TGI, e o desenvolvimento dos órgãos além de definir a produtividade da fábrica.

Feed production in the poultry industry worldwide has always faced great challenges, thus motivating the research development aimed to improving the physical and chemical characteristics of the food supplied to broilers and their performance. The feed mill is the most important factor within the poultry production, as 70% of the total costs are attributed to the feed. Thus, it is necessary to develop production techniques that ensure better availability and homogeneity of nutrients in the feed, enabling its efficient utilization by broilers. This study aimed to evaluate the impact of the pellet durability index (PDI) and the feed hardness on the performance and other factors of broilers through a systematic review. Scientific publications on the effect of PDI and hardness on performance and other parameters of broilers were searched in databases. The study was carried out based on 30 articles selected from the databases of the CAPES journals portal: Isi Web of Science, PubMed, Science Direct, Scielo and Scopus. Articles published from 2004 to 2019 were selected (15 years). There were a total of 16,446 broilers aged 1-21, 7-21, 22-42, 14-21, 1-42, and 25-42 days. The most represented aspects were the performance parameters (feed intake (FI), weight gain (WG), feed conversion (FC) and metabolizable energy (ME) of the diet). Metabolizable energy (ME), nitrogen-corrected metabolizable energy (MEn), ileal digestibility coefficient of dry matter (IDCDM), apparent ileal digestibility coefficient of dry matter (AIDCDM), ileal amino acid digestibility coefficient (IDCAA), breast yield, proventricle, gizzard and pancreas weight, proventricular pH and gizzard, starch gelatinization, cecal microbiota and feed mill productivity. The data were adjusted to Pearson's linear statistical model (r) (p <0.05; p <0.01 and p <0.001), in order to measure the correlation degree between the variables. For PDI of 14-21 days and for CR it was 0.75 (p <0.05), WG 0.60 (p <0.05) and FC 0.29 (p <0.05) which were considered low, although significant. For FI of 22-42 days the correlation was -0.67 (p <0.05) and for WG 0.63 (p <0.05). For MEn of 1-21, it was -0.99 (p <0.01), and this is due to the fact that, in this period, the GIT is immature which leads to a highly negative effect. For the IDCAA, from 7 to 21 days the correlation was 0.90 (p <0.01). In this phase, chickens have a greater nutrient utilization due to the digestion kinetics and nutrients absorption, promoting the breakdown of amino acids. For gelatinization of 21-42 days, it was 0.96 (p <0.01), a positive response where the pelletizing temperature is directly proportional to the pellet quality, besides favoring the breakdown of amino acids in the ileum. For the hardness and FI of 14-21 and 22-42 days the correlation coefficient was 0.62 (p <0.05) and 0.74 (p <0.01), although from 7-21 d the correlation was negative -0, 66 (p <0.01). For WG 14-21 and from 22 to 42 d it was 0.55 and 0.78 (p <0.05 and p <0.01). From 7-21 d it was a significant negative of -0.87 (p <0.01), being a consequence of the slow adaptive process of the GIT. For CR 22-42 it was -0.86 (p <0.001). For DM from 1-21 and 7-1 from 0.90 and 0.94 (p <0.001), respectively. AIDCDM and IDCAA of 1-2 d was 0.68 (p <0.01), where chickens showed a decrease in feed selectivity leading to saving more energy during this growth phase. For gelatinization of 1-21d the correlation was 0.70 (p <0.01), a positive result where higher temperature leads to an increase in the surface pellets tension increasing their hardness. The PDI and the feed hardness have a positive or negative impact on the performance and other physiological factors of broilers, considering aspects such as the benefits at the GIT, and the and the organ development in addition to defining the feed mill productivity.

Densidade de aves e tipos de cama na criação de frangos de corte no ecótono Amazônia Cerrado: Desempenho e uso da termografia na identificação de pododermatite

Dois experimentos foram realizados com o objetivo de avaliar o desempenho, a qualidade de carne e a incidência de lesões de pododermatite em frangos de corte, criados sobre dois tipos de cama e duas densidades. No experimento I e II, foram utilizados 216 pintos de corte, mistos, de um dia de idade, da linhagem Cobb 500®, com peso inicial médio de 54 g ± 3,37 g, distribuídos em delineamento experimental inteiramente casualizado (DIC), em arranjo fatorial 2x2, dois tipos de cama (maravalha e palha de arroz) e duas densidades (24 e 30 kg/m2), com quatro tratamentos (palha de arroz e 24 kg/m2, palha de arroz e 30 kg/m2, maravalha e 24 kg/m2 e maravalha e 30 kg/m2) e seis repetições. No experimento I, foram avaliados o consumo de ração, o ganho de peso, a conversão alimentar, o rendimento de carcaça, os rendimentos de cortes nobres, o peso relativo das vísceras comestíveis, os órgãos imunes, o peso e o comprimento do intestino delgado, a gordura abdominal, os parâmetros sanguíneos, as proteínas totais e albumina, a coloração da carne do peito, perda de peso por descongelamento, perda de peso por cocção, o pH e a força de cisalhamento. No experimento II, foram avaliados os valores de pH, umidade e temperatura da cama, as temperaturas superficiais máximas, mínimas e a amplitude térmica do coxim plantar dos pés, de frangos de corte dos 28 aos 42 dias de idade e o escore visual do coxim plantar dos pés aos 42 dias. Observou-se que no experimento I, os tipos de cama não influenciaram o consumo de ração, o ganho de peso e o peso corporal. Havendo efeito sobre a conversão alimentar. As diferentes densidades influenciaram o consumo de ração e o ganho de peso, sem efeito para a conversão alimentar e o peso corporal. Houve interação entre os tipos de cama e as densidades para o consumo de ração, o ganho de peso, a conversão alimentar e o peso corporal aos 42 dias de idade. Os tipos de cama e as densidades não afetaram os rendimentos de carcaça, coxa e sobrecoxa, no entanto, houve efeito da densidade para o rendimento de peito. Os pesos relativos das vísceras comestíveis, os órgãos imunes, o peso e o comprimento do intestino delgado, a qualidade da carne e os parâmetros sanguíneos não foram influenciados pelos tratamentos, porém, o tipo de cama, influenciou a gordura abdominal e a enzima aspartato aminotransferase (AST). No experimento II, observou-se que não houve interação entre os tipos de cama e as diferentes densidades, para as temperaturas máxima, mínima e para a amplitude térmica. No entanto, a temperatura mínima e a amplitude térmica, foram influenciadas pelos tipos de cama e pelas densidades, sem efeito sobre a temperatura máxima. As densidades e os tipos de cama não influenciaram os valores de pH, umidade, temperatura da cama e o escore visual do coxim plantar de frangos de corte abatidos aos 42 dias de idade. Conclui-se que a cama de maravalha e a densidade de 24 kg/m², apresentaram os melhores resultados de desempenho para frangos de corte de um aos 42 dias de idade e que a termografia foi eficiente para evidenciar que os frangos de corte criados sobre a cama de palha de arroz e a densidade de 30 kg/m², apresentaram menores temperaturas mínima no coxim plantar, indicando indícios de lesões de pododermatite dos 28 aos 42 dias de idade.

Two experiments were conducted to evaluate the performance, meat quality the use of thermography to detect signs of pododermatitis of broiler chickens reared on two different litter materials and at two stocking densities. In experiments I and II, 216 one-day-old Cobb 500® broiler chicks of mixed sex with a mean initial weight of 54 ± 3.37 g were used. The chicks were allotted in a completely randomized design (CRD) in a 2x2 factorial arrangement: two litter materials (wood shavings and rice hulls) and two stocking densities (24 and 30 kg/m2), totaling four treatments (rice hulls and 24 kg/m2, rice hulls and 30 kg/m2, wood shavings and 24 kg/m2 and wood shavings and 30 kg/m2) and six replicates. In experiment I, the following variables were evaluated: feed intake, weight gain, feed conversion, carcass yield and prime cuts, the blood parameters, total proteins and albumin, edible viscera, immune organs, intestine weight and length, abdominal fat, breast meat color, pH and shear force. In experiment II, the values of litter pH, moisture and temperature, the visual score and the maximum and minimum surface temperatures and thermal amplitude of the plantar surface of the footpad of broilers from 28 to 42 days of age were evaluated. In experiment I, the different litter materials did not influence feed intake, weight gain, and body weight but it affected the feed conversion. The different stocking densities influenced feed intake and weight gain, with no effect on feed conversion and body weight. There was an interaction between litter material and stocking density for feed intake, weight gain, feed conversion and body weight at 42 days of age. Litter materials and stocking densities did not affect the yields of carcass, drumstick, and thigh. However, there was an effect of stocking density on breast yield. The relative weight of the edible viscera, the immune organs, the weight and length of the small intestine, the meat quality and the blood parameters were not influenced by the treatments. However, the litter material influenced the abdominal fat and the enzyme aspartate aminotransferase (AST). In experiment II, there was no interaction between litter materials and different stocking densities for maximum and minimum temperatures and thermal amplitude. However, the minimum temperature and the thermal amplitude were influenced by different litter materials and stocking densities, with no effect on the maximum temperature. The stocking densities and litter materials did not influence the values of litter pH, moisture and temperature, and the visual score of the plantar surface of the footpad of broilers slaughtered at 42 days of age. It was concluded that the bed of shavings and the density of 24 kg / m² presented the best performance results for broiler chickens from one to 42 days of age and that the thermography was efficient to show that broiler chickens raised on bed of rice straw and density of 30 kg / m², presented lower minimum temperatures in the plantar cushion, indicating indications of lesions of pododermatitis from 28 to 42 days of age.

Effect of dietary supplementation of marigold pigment on immunity, skin and meat color, and growth performance of broiler chickens

Marigold flower extract, a natural pigment, was used to determine its effect on carcass and skin pigmentation, immunity and growth performance of broiler chickens. Two hundred and forty 1-day-old Arbor Acres broiler chicks were randomly distributed into four treatment groups with six replicates in a randomized block design. Birds were fed basal diet for 42 d with or without supplementation of marigold flower extract at various concentrations, i.e., 0 (MG0, control), 100 (MG100), 150 (MG150) and 200 (MG200) mg/kg of feed, respectively. Feed intake and live body weight were weekly recorded. Carcass and shank color, and antibody titers against Newcastle and Influenza viruses were measured. Results showed that marigold flower extract significantly (p<0.05) improved live body weight and relative thymus weight. However, feed intake, feed conversion ratio (FCR), and spleen and bursa weights were not significantly affected. Yellowness (b*) of breast and thigh muscles increased by the dietary supplementation of marigold flower extract compared with the control diet. However, lightness (L*), redness (a*) and redness to yellowness ratio (a/b) were not influenced by the treatments. Moreover, Roche color fan scores of the shank skin were increased at market age (d 42). The results revealed that marigold extract enhanced antibody titers against Newcastle and influenza viruses. It was possible to conclude that the dietary supplementation with marigold flower extract at the rate of 200 mg/kg of feed enhanced carcass and shank color, antibody titers against ND and AI, and growth performance of broiler chickens.(AU)

Effect of dietary supplementation of marigold pigment on immunity, skin and meat color, and growth performance of broiler chickens

Marigold flower extract, a natural pigment, was used to determine its effect on carcass and skin pigmentation, immunity and growth performance of broiler chickens. Two hundred and forty 1-day-old Arbor Acres broiler chicks were randomly distributed into four treatment groups with six replicates in a randomized block design. Birds were fed basal diet for 42 d with or without supplementation of marigold flower extract at various concentrations, i.e., 0 (MG0, control), 100 (MG100), 150 (MG150) and 200 (MG200) mg/kg of feed, respectively. Feed intake and live body weight were weekly recorded. Carcass and shank color, and antibody titers against Newcastle and Influenza viruses were measured. Results showed that marigold flower extract significantly (p 0.05) improved live body weight and relative thymus weight. However, feed intake, feed conversion ratio (FCR), and spleen and bursa weights were not significantly affected. Yellowness (b*) of breast and thigh muscles increased by the dietary supplementation of marigold flower extract compared with the control diet. However, lightness (L*), redness (a*) and redness to yellowness ratio (a/b) were not influenced by the treatments. Moreover, Roche color fan scores of the shank skin were increased at market age (d 42). The results revealed that marigold extract enhanced antibody titers against Newcastle and influenza viruses. It was possible to conclude that the dietary supplementation with marigold flower extract at the rate of 200 mg/kg of feed enhanced carcass and shank color, antibody titers against ND and AI, and growth performance of broiler chickens.

AVALIAÇÃO DE PROCESSOS TÉRMICOS EM DIETAS PARA FRANGOS DE CORTE COM DIFERENTES COMPOSIÇÕES

Para avaliar os possíveis benefícios que o processo de tratamento térmico por expansão pode trazer as dietas para frangos de corte com a inclusão ou não de farelo de arroz parboilizado (FAP), foram realizados dois estudos. O primeiro estudo avaliou desempenho e rendimento de carcaça no período de 1 a 42 dias, o segundo estudo compreendeu um ensaio de digestibilidade em baterias experimentais, ambos com seis tratamentos. O primeiro estudo foi realizado em aviário experimental composto por 96 boxes experimentais, cada unidade experimental foi composta por 40 frangos de corte machos. No segundo estudo, para o ensaio de digestibilidade foram utilizados 384 frangos de corte machos em um período de 1 a 21 dias de idade com oito repetições de oito aves cada. Aos 21 dias foi realizada a coleta de conteúdo ileal para analise de digestibilidade. O delineamento utilizado em ambos os estudos foi o inteiramente casualizado em esquema fatorial (2x3), duas dietas (uma a base de milho e a outra com a inclusão de 20% de FAP) e 3 tipos de processos, sendo dietas fareladas, peletizadas e expandidas peletizadas, todas isonutritivas. As médias quando apresentaram diferenças a nível de 5% de significância, foram comparadas pelo teste de Tukey. No estudo de desempenho e rendimento de carcaça, as aves alimentadas com dietas à base de milho, apresentaram melhor conversão alimentar, índice de eficiência produtiva e rendimento de carcaça, quando comparadas às aves que receberam dietas contendo 20% de FAP. O uso do expander no processo de fabricação de dietas para frangos de corte melhorou os índices de desempenho, proporcionando melhoria na conversão alimentar em comparação às aves alimentadas com dietas fareladas no período de 1 a 42 dias de idade. No estudo de digestibilidade a expansão de dietas promoveu aumento no coeficiente de digestibilidade da matéria seca, proteína bruta, extrato etéreo e amido, em relação ao processo de peletização. Aves alimentadas com inclusão de 20% de FAP na dieta, no período de 1 a 21 dias, apresentaram queda de desempenho e do coeficiente de digestibilidade da matéria seca, proteína bruta, extrato etéreo e amido em relação às aves que recebem dieta a base de milho.

To evaluate the possible benefits that the heat treatment process by expansion can bring the diets for broilers with the inclusion or not of rice bran parboiled (RBP), two studies were conducted. The first study evaluated performance and carcass yield in the period 1-42 days, the second study comprised a digestibility trial in experimental batteries, both with six treatments. The first study was performed in an experimental avian composed of 96 experimental boxes, each experimental unit was made up of 40 broiler chicks. In the second study, for the digestibility trial were used 384 male broiler chicks in a period of 1 to 21 days of age with eight repetitions of eight birds each. At 21 days was held ileal content collection for digestibility analysis. In the both studies was used a completely randomized experimental design in a 2 x 3 factorial arrangement, two diets (one based on corn and the other with the inclusion of 20% RBP) and 3 types of processes, and mash diets, pelleted and expanded pelleted, all isonutritives. The mean they when presented differences in 5% significance were compared by Tukey test. In performance studies and carcass yield, the broilers fed corn-based diets showed higher feed conversion, productive efficiency ratio and carcass yield, when compared to broilers fed diets containing 20% RBP. The use of the expander in diets for broilers in manufacturing process provide better performance index and feed conversion major compared to the broilers fed with mash diet in the period 1-42 days old. In the digestibility study the expansion of diets promoted an increase in the digestibility of dry matter, crude protein, ether extract and starch, compared to the pelleting process. Broilers fed inclusion of 20% RB in the diet, from 1 to 21 days, showed drop in performance and digestibility of dry matter, crude protein, ether extract and starch in relation to broilers receiving the corn-based diet.

Period of incubation and posthatching holding time influence on broiler performance

The present study had the objective of investigating the performance of broilers housed immediately after hatching or after a 12 or 24 hour of post-hatching holding time. One thousand and six hundred male Ross 308 broiler chicks with an initial body weight of 46 grams were used. These chicks were distributed in a completely randomized experimental design with 5 treatments and 8 replications of 35 birds in each treatment. The treatments in this study consisted of the removal of chicks from the hatchery in three different times: after 480, 492 and 504 hours of incubation. In each one of these times, 280 chicks were removed from the hatchery and immediately housed. Another group of an identical number of chicks of each time remained in the hatchery to be housed at 504 hours after hatching. The chick group corresponding to those hatched at 480 and 492 hours performed better until 7 days. However, no differences in body weight or body weight gain were observed at the end of the study. Feed efficiency, however was worse for the birds hatched and placed at 480 hours. There were no differences among treatments for mortality.

Period of incubation and posthatching holding time influence on broiler performance

The present study had the objective of investigating the performance of broilers housed immediately after hatching or after a 12 or 24 hour of post-hatching holding time. One thousand and six hundred male Ross 308 broiler chicks with an initial body weight of 46 grams were used. These chicks were distributed in a completely randomized experimental design with 5 treatments and 8 replications of 35 birds in each treatment. The treatments in this study consisted of the removal of chicks from the hatchery in three different times: after 480, 492 and 504 hours of incubation. In each one of these times, 280 chicks were removed from the hatchery and immediately housed. Another group of an identical number of chicks of each time remained in the hatchery to be housed at 504 hours after hatching. The chick group corresponding to those hatched at 480 and 492 hours performed better until 7 days. However, no differences in body weight or body weight gain were observed at the end of the study. Feed efficiency, however was worse for the birds hatched and placed at 480 hours. There were no differences among treatments for mortality.