This study was carried out to evaluate the requirements of digestible threonine in diets of gilts from 15 to 30kg, maintained in thermoneutral environment. Seventy crossbreed gilts with an initial weight of 15.1 ± 0.4 kg were used in a randomized blocks design, with five treatments (levels of digestible threonine), seven replicates and two animals per experimental unity. The treatments corresponded to the levels of 0.54, 0.58, 0.61, 0.65, e 0.698% of digestible threonine. Digestible threonine levels in the diet […]

This study was carried out to evaluate the requirement of digestible threonine in diets of gilts from 30 to 60 kg, maintained thermoneutral environment. Seventy crossbreed gilts with an initial weight of de 30.0 ± 0.61 kg were used in a randomized blocks design, with five treatments (levels of digestible threonine), seven replicates and two animals per experimental unity. The treatments corresponded of the levels of 0.50; 0.53; 0.56; 0.60; and 0.63% of digestible threonine. No effect was observed of […]

This study was conducted to evaluate the effect of the temperature and rearing system on the apparent metabolizable energy requirements for maintenance (MEm) for broiler breeder hens. In the experiment 1, MEm was determined with birds in cages. One hundred-ninety-two birds were housed in climatic chambers at 13, 21 and 30ºC. The birds were assigned to four treatments with four replications of four birds each. The treatments were: ad libitum intake, 70, 50 and 30% of ad libitum intake. Comparative […]

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 […]

ABSTRACT – The effect of environmental temperature on performance and carcass characteristics in broilers pair-fed and two levels of metabolizable energy was evaluated. One hundred and sixty Hubbard male broilers, with 21 days of age and 791±4.12 g average initial weight were allotted either under thermoneutral environment (23.3±0.58ºC) or under hot environment (32.3±0.31ºC) up to 42 days of age. A completely randomized design in a 2 x 2 factorial arrangement (level of metabolizable energy [3075 and 3300 kcal of ME/kg] […]