This study was conducted to determine the effect of microbial or antimicrobial additives on the performance and organ morphology of broilers raised in batteries or in floor pens. The effect of microbial additives on the presence of oocysts in the litter was also studied. Experiments 1 and 2 consisted of four treatments (non-supplemented control diet or diet supplemented with avilamycin, bacitracin methylene disalicylate or enramycin) and six repetitions in a randomized block design. In Experiment 1, 288 day-old chicks were housed in heated batteries in a environmentally controlled room, 12 chicks per cage; in Experiment 2, 1,200 day-old chicks were housed in a curtain-sided experimental house, with concrete floor and rice hulls as litter material, 50 chicks per pen. Experiments 3 and 4 were carried out similarly to Experiments 1 and 2, respectively, but the treatments consisted of microbial additives (non-supplemented control diet or Bacillus subtilis added to the feed plus Lactobacillus reuteri and Lactobacillus johnsonii added to the water, undefined microflora added to the water or live yeast added to the feed). The antibiotics did not affect the performance of birds raised in batteries, but improved feed conversion, weight gain and live weight when chickens were kept on the floor pens. Microbial additives did not affect bird performance in any environment; however, treatments affected liver weight. Microbial agents increased intestinal weight in floor-raised broilers. No relationship was seen between the use of microbial additives and the presence of oocysts in the litter

There are some evidences described in the literature showing reduced energy metabolizability of ingredients for newly hatched chicks. Hence, a metabolism trial was carried out with the objective of determining the metabolizable energy of corn grain, soybean meal and micronized full fat soybean for newly hatched chicks. The method of total excreta collection was used in an experiment with 192 male chicks from one to seven days, distributed in a completely randomized design with four treatments and four replicates of twelve birds. Excreta were collected from four to seven days of age. The treatments included a reference diet, two test-diets consisting of 60% of the reference diet and 40% of the test ingredients: corn grain (CG) and soybean meal (SM), and one test-diet consisting of 80% of the reference diet and 20% of micronized full fat soybean (MFFS). The N-corrected apparent metabolizable energy (AMEn) and the metabolizability coefficient of gross energy (MCGE) of the ingredients determined for the chicks were respectively 3,213 kcal/kg and 81.6% for CG; 2,085 kcal/kg and 49.7% for SM and 4,068 kcal/kg and 74.8% for MFFS