ABSTRACT Post-hatch delayed placement damages, physical and physiological development of broiler chicks. The objective of this study was to ascertain adequate levels of glutamine inclusion in post-hatch and pre-starter feed, in order to minimize the negative effects of post-hatch delayed placement on broiler chicks. The birds were distributed in a completely randomized design, with four treatments and five replicates of ten birds each. Four levels of glutamine supplementation (0, 1, 2 and 3%) were used in the pre-starter feed, which was given to the chicks in the transportation box and during the pre-starter phase. After 24 hours of access to this feed, and at 7 days of age, the chicks’ performance, yolk sac retraction, plasma glucose concentration, weight and small-intestine histomorphometry were evaluated. From seven to ten days of age, a metabolizability assay was performed. Glutamine supplementation tended to increase the use of the yolk sac, the concentration of plasma glucose (p<0.10) and the depth of the crypt in the ileum after 24 hours of life (p<0.05). There was no statistical difference between the glutamine supplementation levels, in relation to glucose, histomorphometry or metabolizability in the pre-starter phase. Glutamine concentrations did not differ in relation to performance, histomorphometry of the small intestine or metabolizability of nutrients in the pre-starter phase.

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.

ABSTRACT Two experiments were conducted to evaluate the effect of broiler breeder age and incubator type on hatching parameters, hatch window, embryo diagnosis results, and hatchling physical quality. The treatments consisted of a combination of three broiler breeder ages (29, 35 and 59 weeks of age) and two incubator types (single stage, SS; or and multiple stage, MS). A completely randomized design in a 3x2 factorial arrangement was applied. In Experiment I, 1,896 eggs were used and 360 eggs in Experiment II. There was an interaction between breeder age and incubator type only for hatchling physical quality score. Independently of incubator type, hatchability rate, late embryo mortality, and egg contamination were higher in the eggs laid by older breeders (59-wk-old). Early mortality (0-4 days) was higher in the embryos from young breeders (29-wk-old). A shorter hatch window birth was obtained in the SS incubator, resulting in higher hatchling body weight relative to egg weight, and better hatchling physical quality score. Both types of incubators provide good conditions for embryo development; however, the physical quality of chicks derived from eggs from intermediate-aged breeders (35-wk-old) is better when eggs are incubated in SS incubators.

Abstract Conventional bacteriology techniques and quantitative polymerase-chain reaction (qPCR) were applied to the eggshell, albumen, and yolk of washed and unwashed commercial white and brown eggs, to detect Salmonella spp. Pooled samples of eggshells, albumen, and yolk of white and brown eggs were collected at the poultry house and at the egg-storage room. Salmonella spp. was detected by conventional bacteriology in 5.4% (21/387) of analyzed samples and in 16% (68/387) by qPCR. In the 114 unwashed white eggs samples of eggshell, albumen and yolk, the bacterium was identified in 2.6% of the eggs (3/114) by conventional bacteriology and in 13.2% (15/114) by qPCR. In the 90 samples of washed eggs, 6.7% (6/90) were contaminated as detected by conventional bacteriology and 10.0% (9/90) by qPCR. In the 81 samples of unwashed brown eggs, Salmonella spp. was detected in 6.1% of the eggs (5/81) by conventional bacteriology and 27.2% (22/81) by qPCR. In the 102 samples of brown washed eggs, 6.9% (7/102) where positive by conventional bacteriology and 35.3% (16/102) by qPCR. All samples detected as positive by conventional bacteriology were also positive by qPCR. Salmonella Agona represented 18.2% (4/22) of identified serovars, Salmonella enterica subs. enterica O: 4.5 18.2% (4/22), Salmonella Schwarzengrund 18.2% (4/22), Salmonella Cerro 13.6% (3/22), Salmonella Anatum 13.6% (3/22), Salmonella Enteritidis 9.1% (2/22), Salmonella Johannesburg 4.5% (1/22), and Salmonella Corvallis 4.5% (1/22). The qPCR method provided better detection of Salmonella spp. in commercial eggs than conventional bacteriology. The conventional egg washing and disinfection procedures are not efficient to eliminate Salmonella.

This experiment aimed at evaluating the influence of the supplementation of digestible lysine and digestible arginine at different ratios in the diet fed to layers between 24 to 44 weeks of age on egg quality. In total,320 Lohmann LSL laying hens were allotted according to a completely randomized design in a 2 x 4factorial arrangement, consisting of two digestible lysine levels (700 or 900 mg/kg of diet) and four digestible arginine levels (700, 800, 900,or 1000 mg/kg of diet). Diets contained, therefore, digestible Lys:Arg ratios of 100, 114, 128, and 142 when the diet contained 700 mg digestible lysine per kg of diet, and 78, 89, 100, and 111 when 900 mg digestible lysine per kg was supplemented. The data obtained with digestible arginine levels were fitted to polynomial regression equations, and with digestible lysine, the F test (5% probability) was used to compare the means. The following variables were evaluated: egg weight; internal egg quality (yolk percentage and index, albumen percentage, Haugh units), eggshell quality (specific gravity andeggshell percentage); and whole egg, albumen, and yolk solids content. Digestible lysine and arginine interaction did not affect egg quality. Increasing levels of digestible lysine and arginine reduced eggshell quality and albumen solids, respectively. The levels of these amino acids suggested to improveegg quality are 700 mg digestible lysine and 700 mg digestible arginine/kg of feed at a Dig Lys: Dig Arg ratio of 100.

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.

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.

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.

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.

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 chick’s 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.