A study with 2,400 broilers was carried out to compare the effect of the use of mannanoligosaccharides, Saccharomyces cerevisiae cell wall or growth promoter (Olaquindox) in the diet on broiler. Diets were based on corn and soybean meal. A completely randomized experimental design was used, and the obtained data were evaluated by analysis of variance and test of Tukey at a level of 5%. The following parameters were measured: feed intake, daily weight gain, feed conversion ratio, and mortality. It was concluded that the effect of the inclusion of mannanoligosaccharides in the diet on the studied parameters was significantly higher as compared to the inclusion of cell wall or to the control diet, but the effect was not different as compared to the inclusion of growth promoter.

An experiment was conducted to evaluate the effect of different digestible amino acid profiles on the performance of broilers in two phases: from 1 to 21 days and from 22 to 42 days of age. At the end of the experiment, carcass yield and cut percentages were evaluated. Nine hundred and sixty AgRoss birds were distributed in a randomized block design with four treatments (four digestible amino acid profiles): Rostagno et al. (2000), Baker & Han (1994b), Degussa (1997) and those recommended by AgRoss (2000), with six repetitions and 40 birds per repetition (20 males and 20 females). The results showed that the four diets were able to provide the requirements of the birds, since no significant differences were seen among the treatments on the performance in the two phases and on the carcass yield and cuts at 42 days of age. Males had better yields of feet, head and neck, and lower percentage of abdominal fat (p<0.05). The best cost/benefit ratio was seen for the profile established by Rostagno et al. (2000) when diets were evaluated in an ideal protein situation.

Foram utilizados 2.880 pintos de corte, para avaliar os efeitos de diferentes fontes de sódio (Na+) e relações sódio:cloro (Na+:Cl-) na ração. As aves receberam ração e água ad libtum. O delineamento experimental foi inteiramente casualizado, com quatro tratamentos e seis repetições. O ganho de peso, consumo de ração, conversão alimentar e mortalidade não foram influenciados (p>0,05) pela substituição da fonte tradicional de Na e pelas diferentes relações Na:Cl. A umidade da cama foi afetada pela fonte e níveis de Na na ração. Os resultados mostraram que pode-se utilizar o NaHCO3 como fonte parcial à exigência de Na para frangos de corte de 1 a 47 dias de idade.

A trial was carried out with 2,880 day old chicks to evaluate different sources of sodium (Na+) and Na+:Cl- ratio in diets. Water and diets were available in "ad libitum" feeding. Experimental design was completely randomized with four treatments and six repetitions. The performance (feed intake, body weight, feed conversion and mortality) was not affected (P>0.05) by treatments, but different levels and sources of Na+ increased litter moisture. The NaHCO3 can be used in chicken broilers diets in partial substitution of Na for day 1 to 47.