Efeito do Nível de Energia da Dieta e da Exposição Prévia ao Calor sobre a Respiração Mitocondrial do Músculo Cardíaco de Frangos de Corte

This work was conducted aiming to evaluate the effect of dietary energy level and the previous heat exposure on the respiratory activity of the mitochondria from the cardiac muscle of broiler chickens. It was used broiler chickens (Hubbard) from both sexes and fed with diet containing 2900 kcal ME/kg or 3200 kcal ME/kg. The birds were heat stressed (35°C/4h) in the 1 st, 21 st and 42 nd days of age. The respiratory activity of mitochondria from cardiac muscle was evaluated in a Gilson oxygraph, model 5/6, by using alpha-ceto-glutaric as substrate and the ADP (adenosine-di-phosphate) to stimulate the respiratory activity. There was not effect of dietary energy level and previous heat exposure on the respiratory activity of the mitochondria from cardiac muscle. However, the females presented higher respiratory activity than males. By reason of the low oxidative capability of the heart muscle fiber of the male broiler chickens, these could be more sensitive to cardiac disease than females

Effects of glutamine on performance and intestinal mucosa morphometry of broiler chickens vaccinated against coccidiosis

This study aimed to assess the effects of glutamine as feed additive on performance and intestinal mucosa morphometry of broiler chickens vaccinated against coccidiosis. A total of 400 day-old male chicks were randomly assigned to four treatments (NVNG – no vaccination, no glutamine supplementation; NVG – no vaccination, glutamine supplementation (10 g kg−1); VNG – vaccination, no glutamine supplementation; VG – vaccination, glutamine supplementation) replicated four times with 25 birds per replicate. A commercial sprayed-on vaccine against coccidiosis containing Eimeria acervulina, E. maxima, E. mivati, and E. tenella was administered at the hatchery. Broiler performance was evaluated from 1-28 days, and morphometric parameters were analyzed at 14, 21, and 28 days of age. Body weight gain and feed intake were negatively affected by vaccination, but not by glutamine. Vaccination increased crypt depth in the duodenum and jejunum at 21 and 28 days. In conclusion, this study showed that glutamine was not able to increase weight gain of broiler chickens, irrespective of whether the animals were vaccinated or not against coccidiosis. Glutamine supplementation was able to improve feed conversion in vaccinated birds suggesting trophic effect on intestinal epithelium improving

Roof pitch and exposure and different roofing materials in reduced models of animal production facilities in the fall and winter

AbstractThe objective was to verify the influence of roof pitch, exposure and roofing material on the internal temperature of reduced models of animal production facilities. For the development of the research, 48 reduced models with dimensions 1.00 × 1.00 × 0.50m were used. The roof was shed-type, and models faced the North or South directions, with 24 models for each side of exposure. Ceramic, galvanized-steel and fibro tiles were used to build the roofs. Pitches varied between 20; 30; 40 and 50% for the ceramic tile and 10; 30; 40 and 50% for the other two. Inside the model, temperature readings were performed at every hour, for 12 months. The results were evaluated in a general linear model in a nested 3 × 4 × 2 factorial arrangement. As the roof pitch increased, the internal temperature within the model dropped, so utilizing sharper pitches (50%) for ceramic and fibro roofs with a larger area facing the South can provide lower temperatures within the animal production facilities. In regions where the cold is more stressful than the heat, having animal production facilities with larger roof exposure to the North may minimize the losses caused by cold stress

Efeitos da restrição alimentar protéica ou energética sobre o crescimento de frangos de corte criados em diferentes temperaturas ambiente Effect of protein or energy restriction on broilers growth reared at different environmental temperatures

O presente experimento foi conduzido com o objetivo de avaliar o efeito da restrição protéica ou energética, entre o 8º e o 14º dia de idade, sobre o crescimento e a composição da carcaça de frangos de corte criados em diferentes temperaturas ambientes. Foram utilizados 900 pintos de um dia, machos, da linhagem Ross, os quais foram alojados em três diferentes câmaras climatizadas nas temperaturas de 18, 25 ou 33°C, do 1º ao 42º dia de idade. Para cada temperatura, o delineamento experimental utilizado foi o inteiramente casualizado, em esquema de parcelas subdivididas, em que as parcelas corresponderam ao programa alimentar (controle - 2850 kcal EM/kg e 20% de proteína bruta do 1º ao 21º dia de idade e 3040 kcal EM/kg e 17% de PB do 22º ao 42º dia; restrição energética - 2565 kcal EM/kg e 20% de PB e restrição protéica - 2850 kcal EM/kg e 15% de PB entre o 8º e o 14º dia de idade) e as subparcelas, à idade das aves. Entre o 1º e o 7º dia de idade e após o período de restrição as aves receberam a mesma dieta do que os animais controles. Foram avaliados o peso vivo e a composição da carcaça das aves. Os resultados mostraram que, de forma independente da temperatura de criação, as restrições alimentares (energética ou protéica) não afetaram o peso vivo e a composição da carcaça aos 42 dias de idade, evidenciando que o frango em temperaturas ambientes diversas mantém a capacidade de ganho compensatório.<br>The present experiment was conducted to evaluate the effect of protein or energy restriction from 8th to 14th days of age, on growth and carcass composition of broiler chickens raised at different environmental temperatures. It was used 900 day-old, male chickens from Ross strain, reared in three environmentally controlled rooms where ambient temperature were maintained at 18, 25 and 33°C up to 42 days of age. For each temperature, a split-plot design was used with feed program as the main plot (control - 2850 kcal ME/kg and 20% of crude protein from 1 to 21 days and 3040 kcal ME/kg and 17% of crude protein from 22 to 42 days; energy restriction - 2565 kcal ME/kg and 20% of crude protein and protein restriction - 2850 kcal ME/kg and 15% of crude protein from 8th to 14th days of age) and age as the sub-plot. From 1 to 7 days of age and after restriction period, the chicks were fed with the control diet. The body weight and carcass composition were analyzed. The results showed that, irrespective of ambient temperature, the qualitative energy or protein restriction did not affect the body weight and carcass composition at 42 days of age, indicating that broilers kept a compensatory gain ability in different ambient temperatures