RESUMO
ABSTRACT The objective of this study was to evaluate the effects of dietary inclusion of protected sodium butyrate (PSB) on the intestinal development and feed nutrient metabolizability of commercial laying hens. The birds started to receive the treatment rations at 58 weeks of age. At 76 weeks of age the laying hens were distributed in a randomized block design to four treatments (0, 105, 210 and 300 g t-1/PSB), six replicates, and two birds/replicate. The nitrogen balance (NB), ether extract balance (EEB), dry matter metabolizability coefficient, nitrogen, ether extract, ash, apparent metabolizable energy (AME), and AME corrected by nitrogen (AMEn) were evaluated. For assessment of intestinal development, we evaluated the duodenum, jejunum, ileum, cecum, and colorectal lengths, the relative intestine weight and villus height, crypt depth, and villus:crypt ratio of the duodenum, jejunum, and ileum. A decreasing linear effect was observed in the duodenum length, while an increasing linear effect was observed in the height of the duodenum and jejunum villi. A quadratic effect was found in the jejunum crypt depth. A linear increasing effect was found on the villus:crypt ratio of the duodenum and jejunum, and a quadratic effect was observed in the ileum. Quadratic and increasing linear effects were observed in the NB and EEB, respectively. Additionally, increasing linear effects were observed in the AME and AMEn. The dietary addition of 300 g t-1 of PSB improved intestinal development and energy metabolizability of the diet.
RESUMO
The aim of this study was to evaluate the performance, tibial density and mineral content, Na, K ,and Cl serum levels, and dry matter content of the litter of broilers fed diets with different levels of dietary electrolyte balances. Two experiments were carried out: during the starter phase (7 to 21 days of age, 960 broilers) and during the growe phase (22 to 38 days of age, 816 broilers). In both experiments, a completely randomized design with four treatments based on dietary electrolyte balance values (200, 240, 280 and 320 mEq/kg of diet) with four replicates was applied. Birds and diets were weighed when birds were seven, 14 and 21 days of age in the first experiment, and 22 and 38 days of age in the second experiment in order to determine weight gain, feed intake and feed conversion. Final body weight, weight gain, feed intake and feed conversion and mortality rate were evaluated. On days 21 and 38, the left tibia of two birds per replicate was collected to determine bone density and the serum was used for Na and K analysis. Litter dry matter content was also determined on days 21 and 38 . There was no effect of dietary electrolyte balance values on broilers performance between 7 and 14, 7 and 21, or 22 and 38 days of age, tibial bone density and mineral content, or on Na, K and Cl serum levels. Litter dry matter was linearly reduced as dietary electrolyte balance value increased. Diets with 200 mEq/kg may be recommended for broilers from 7 to 38 days of age with no negative influence on the evaluated parameters.
RESUMO
A dose of 0.3 mL of water solution containing 0.00 (control), 0.625, 1.250 or 1.875 µg of 25-hydroxy cholecalciferol (25(OH)D3) was administered to 312 fertile eggs derived from 49-w-old Cobb 500 broiler breeders on the 17th day of incubation (DE17) via allantoic cavity. After treatment, eggs were distributed and maintained until hatching in four incubators set at 37.8 ºC and 55% RH. Each incubator received eggs from all treatments, according to a block design with four treatments of 77-79 replicates each. Hatching was checked every two hours from 484h to 512h of incubation to evaluate productivity and chick qualities. Chicks were housed until 10 days of age in heated battery cages according to a block design with four treatments of 10 replicates of six chicks each for performance and mortality evaluation. Mean hatching time of the chicks treated with 25(OH)D3 during the embryonic phase occurred 4 to 5 h earlier than control group (502:31h), with no effects on hatching or neonate qualities. An inverse linear effect of 25(OH)D3 dose on chick body weight at hatching was observed, but 10-d-old broiler performance and mortality were not affected. The fast body weight recovery of the broilers obtained from the embryos supplemented with the highest 25(OH)D3 level was recorded until 10 days of rearing, equaling final mean body weights (p>0.05) among experimental groups. The results of this study indicate the potential use of 25(OH)D3 as exogenous vitamin supplementation to embryos a few days before hatching without affecting neonate qualities and 10-d-old broiler chicken performance.
RESUMO
Effects of yolk sac removal (deutectomy) upon performance of chicks from three divergent strains were tested to evaluate the importance of endogenous nutrition on the post-hatch phase. Chicks from three different strains (Hy-Line W98, Cobb 500, and JA57) were submitted to a surgery procedure after hatching. Half of them had the residual yolk removed, and the other constituted a sham-deutectomized group. After operation, chicks were designated to a 3 x 2 factorial design (3 strains x 2 presence/absence of yolk sac), in a total of six experimental groups and ten replications of two to four birds. During 14 experimental days all birds were fed ad libitum a 21% CP and 3050 kcal/kg EM mash diet. Data were analyzed by ANOVA, and Tukey's test (p 0.05). Relative yolk sac weights were similar among chicks from different breeders, averaging 11.7% to 13.5%. Comparing to sham-operated, deuctetomized chicks had lower weight gain at 7 and 14d, indicating that endogenous nutrition, via yolk sac, is very important to galliform birds whatever their strain. Hy-line deutectomized chicks gained 40% less body weight at the 7th day as compared to their sham counterparts. Analysis of the same criterion to Cobb and JA57 groups revealed a decrease of 16.1% and 10.8%, respectively, on weight gain efficiency. At the 14th rearing day, Hy-Line chicks had the lowest weight gain, followed by JA57s' and Cobbs'. The results suggested that chicks selected for fast growth are less dependent on endogenous nutrition, responding better when exogenous nutrition is associated to yolk assimilation.
RESUMO
Effects of yolk sac removal (deutectomy) upon performance of chicks from three divergent strains were tested to evaluate the importance of endogenous nutrition on the post-hatch phase. Chicks from three different strains (Hy-Line W98, Cobb 500, and JA57) were submitted to a surgery procedure after hatching. Half of them had the residual yolk removed, and the other constituted a sham-deutectomized group. After operation, chicks were designated to a 3 x 2 factorial design (3 strains x 2 presence/absence of yolk sac), in a total of six experimental groups and ten replications of two to four birds. During 14 experimental days all birds were fed ad libitum a 21% CP and 3050 kcal/kg EM mash diet. Data were analyzed by ANOVA, and Tukey's test (p 0.05). Relative yolk sac weights were similar among chicks from different breeders, averaging 11.7% to 13.5%. Comparing to sham-operated, deuctetomized chicks had lower weight gain at 7 and 14d, indicating that endogenous nutrition, via yolk sac, is very important to galliform birds whatever their strain. Hy-line deutectomized chicks gained 40% less body weight at the 7th day as compared to their sham counterparts. Analysis of the same criterion to Cobb and JA57 groups revealed a decrease of 16.1% and 10.8%, respectively, on weight gain efficiency. At the 14th rearing day, Hy-Line chicks had the lowest weight gain, followed by JA57s' and Cobbs'. The results suggested that chicks selected for fast growth are less dependent on endogenous nutrition, responding better when exogenous nutrition is associated to yolk assimilation.
RESUMO
This trial was carried out in order to evaluate the effect in broiler embryos of cold or heat stress on the hatching characteristics, and on the quality of the newborn chicks. Three hundred eggs obtained from 42-week-old broiler breeders were distributed in three incubators maintained at a temperature of 37.8C, relative air humidity of 60%, and mechanically turned on every two hour. At 16 days of incubation (D16), the embryos were submitted to heat (40C) or cold (32C) stress for 5 hours in two of the three machines. The non-stressed embryos of the third incubator were used as control. The data were analyzed in a complete randomized design with 3 treatments. The hatchability and chicks quality, evaluated by the number of neonatal and viable chicks, body weight at birth, and legs and navel qualities, were not different (P>0.05) among the control and temperature-stressed groups. However, results revealed that the eggs exposed to cold or heat stress showed a longer (P 0.05) incubation period - 506.5h and 504.2h, respectively - than those kept at normal temperature - 496.3h - as a consequence of a delay on internal (7 and 6h) and external piping (13 and 12h). It can be concluded that the 5-hour cold or heat stress at D16 is not enough to damage the hatchability or the quality of the chicks, but increase total incubation period, denoting that even a brief period of variation on the normal incubation temperature at a critical period of development is enough to determine stress in broiler embryos.
O experimento foi conduzido para avaliar o efeito do estresse de temperatura sobre as características de incubabilidade e qualidade dos pintos nascidos. Trezentos ovos, obtidos de um lote de matrizes de frangos de corte com 42 semanas, foram distribuídos em três incubadoras, reguladas para manter uma temperatura de 37,8ºC, umidade relativa de 60% e viragem mecânica a cada duas horas. Aos 16 dias de incubação (D16), aplicou-se uma variação de temperatura de calor (40ºC) ou frio (32ºC) durante cinco horas em duas máquinas. Os embriões da terceira máquina foram usados como controle. Os dados obtidos foram analisados estatisticamente, obedecendo-se a um delineamento inteiramente casualizado, com 3 tratamentos. A eclodibilidade e a qualidade dos pintainhos, avaliados pelo peso ao nascer e qualidade de pernas e umbigo não foram significativamente diferentes entre o grupo controle e os grupos estressados. Os resultados revelaram que os ovos exposto ao estresse pelo frio ou calor tiveram um período de incubação maiores - 506,5h e 504,2h, respectivamente - do que aqueles expostos a temperatura normal - 496,3h - como conseqüência no atraso de bicagem interna (7 e 6 h) e externa (13 e 14 h). Concluiu-se que a alteração da temperatura normal de incubação, com resfriamento ou aquecimento por 5 h no D16, não foi suficiente para prejudicar a eclodibilidade e a qualidade dos pintainhos, mas causou uma dilatação do período total de incubação, indicando que mesmo um breve período de variação da temperatura normal de incubação em um período crítico de desenvolvimento é suficiente para determinar estresse nos embriões de frangos de corte.
RESUMO
This trial was carried out in order to evaluate the effect in broiler embryos of cold or heat stress on the hatching characteristics, and on the quality of the newborn chicks. Three hundred eggs obtained from 42-week-old broiler breeders were distributed in three incubators maintained at a temperature of 37.8C, relative air humidity of 60%, and mechanically turned on every two hour. At 16 days of incubation (D16), the embryos were submitted to heat (40C) or cold (32C) stress for 5 hours in two of the three machines. The non-stressed embryos of the third incubator were used as control. The data were analyzed in a complete randomized design with 3 treatments. The hatchability and chicks quality, evaluated by the number of neonatal and viable chicks, body weight at birth, and legs and navel qualities, were not different (P>0.05) among the control and temperature-stressed groups. However, results revealed that the eggs exposed to cold or heat stress showed a longer (P 0.05) incubation period - 506.5h and 504.2h, respectively - than those kept at normal temperature - 496.3h - as a consequence of a delay on internal (7 and 6h) and external piping (13 and 12h). It can be concluded that the 5-hour cold or heat stress at D16 is not enough to damage the hatchability or the quality of the chicks, but increase total incubation period, denoting that even a brief period of variation on the normal incubation temperature at a critical period of development is enough to determine stress in broiler embryos.
O experimento foi conduzido para avaliar o efeito do estresse de temperatura sobre as características de incubabilidade e qualidade dos pintos nascidos. Trezentos ovos, obtidos de um lote de matrizes de frangos de corte com 42 semanas, foram distribuídos em três incubadoras, reguladas para manter uma temperatura de 37,8ºC, umidade relativa de 60% e viragem mecânica a cada duas horas. Aos 16 dias de incubação (D16), aplicou-se uma variação de temperatura de calor (40ºC) ou frio (32ºC) durante cinco horas em duas máquinas. Os embriões da terceira máquina foram usados como controle. Os dados obtidos foram analisados estatisticamente, obedecendo-se a um delineamento inteiramente casualizado, com 3 tratamentos. A eclodibilidade e a qualidade dos pintainhos, avaliados pelo peso ao nascer e qualidade de pernas e umbigo não foram significativamente diferentes entre o grupo controle e os grupos estressados. Os resultados revelaram que os ovos exposto ao estresse pelo frio ou calor tiveram um período de incubação maiores - 506,5h e 504,2h, respectivamente - do que aqueles expostos a temperatura normal - 496,3h - como conseqüência no atraso de bicagem interna (7 e 6 h) e externa (13 e 14 h). Concluiu-se que a alteração da temperatura normal de incubação, com resfriamento ou aquecimento por 5 h no D16, não foi suficiente para prejudicar a eclodibilidade e a qualidade dos pintainhos, mas causou uma dilatação do período total de incubação, indicando que mesmo um breve período de variação da temperatura normal de incubação em um período crítico de desenvolvimento é suficiente para determinar estresse nos embriões de frangos de corte.
RESUMO
The production performance of Japanese quails receiving increasing levels of pearl millet grain in rations was studied. Two hundred, 70-day-old quails submitted to a completely randomized design with five treatments and four replicates with ten birds each, were fed with 0, 25, 50, 75 and 100% of pearl millet grain in laying rations. The production and weight of eggs and the feed intake, the mortality rate and yolk color by the use of colorimetric fan were measured, and the feed conversion per dozen eggs and in relation to egg mass were calculated. The results indicated that the production performance of laying quails was not affected by the use of increasing levels of pearl millet grain and that pearl millet is a good corn substitute for Japanese quail, but a yolk pigment should be used in the ration.
Avaliou-se o desempenho de codornas-japonesas em postura alimentadas com níveis crescentes de milheto-grão na ração. Duzentas codornas com 70 dias de idade, submetidas a um delineamento inteiramente ao acaso, com cinco tratamentos e quatro repetições de 10 aves, receberam níveis de milheto de 0, 25, 50, 75 e 100% em substituição ao milho em rações na fase de postura. Foram medidos a produção e o peso dos ovos, o consumo de ração, a mortalidade, a coloração da gema pelo leque colorimétrico, e calculada a conversão alimentar em termos de massa e de dúzia de ovos. Os índices de produtividade das codornas não foram afetados pelos diferentes níveis de substituição estudados e o milheto-grão se constituiu em uma fonte de substituição do milho para codornas-japonesas, devendo-se, porém, incluir na ração uma fonte de pigmentação para a gema dos ovos.