-The objective of this study was to determine the coefficients of apparent and true digestibility of protein and amino acids of five feedstuffs (corn, wheat bran, soybean meal, corn gluten meal and fish meal) in 900 sex-reversed Nile tilapia (Oreochromis niloticus) of the Thai strain during the growth phase, with an initial weight of 315±8.45 g. A total of 750 fish were distributed according to a randomized block design (repetitions in time) into five treatments with six replicates of 25 fish each. The remaining 150 fish were fed a protein-free diet to measure endogenous protein and amino acid losses in order to determine the true digestibility of these components. Each tested diet contained a single protein source, which consisted of one of the evaluated feedstuffs. Digestibility was indirectly estimated using chromic oxide at 0.50% as marker. Digesta was collected from the last 5 cm of the distal intestine (between the ileal-rectal valve and the anus) using the dissection technique.

-Essential oils have been extensively used in many commercial applications, one of them being anesthetics. The effect of four essential oils (tea tree, clove, eucalyptus, and mint oils) on the sedation, recovery, and behavioral stress of Nile tilapia (Oreochromis niloticus) was evaluated. The sedative solutions, prepared with essential oils and anhydrous ethanol (1:4), were used for fish management procedures at a dose of 7.4 mL L -1 in a completely randomized block design with four treatments and seven replicates. The means were compared using Scott-Knott test (P < 0.05). Clove oil was found to be the most suitable oil for the immobilization of Nile tilapia; however, behavioral observations indicate that tea tree oil was the most efficient in reducing stress. Keywords

-With the objective to evaluate levels of available phosphorus (aP) in diets for pigs selected for meat deposition by maintaining the calcium and available phosphorus ratio, it was used 50 commercial hybrid female pigs with initial weight of 30.32 ± 0.29 kg, distributed in a complete randomized experimental design, with five treatments, five replicates, and two animals per experimental unit. Treatments were composed of a corn-soybean meal basal diet and four diets obtained by supplementation of basal diet with dicalcium phosphate, resulting in diets with 0.144; 0.224; 0.304; 0.384 and 0.464% of aP.Calcium levels were adjusted by varying the quantities of limestone in the diets. There was no effect of aP on both daily feed intake and feed conversion. Levels of aP affected daily weight gain which increased quadratically up to the estimated level of 0.372%. There was no effect of aP on quantity of phosphorus in the bones. The quantity of calcium in the bones and percentage of ash in the bones were influenced in an increasing linear way by the aP in the rations. The best result of weight gain of swine females, from 30 to 60 kg, genetically selected for meat deposition, is provided by the level of available phosphorus of 0.372%, which corresponds to a relationship with calcium of 2.06:1 and to a daily intake of 8.20 g of available phosphorus.

Streptococcosis causes serious economic losses to fish farms every year. A four-week feeding trial was carried out to evaluate arginine (ARG) supplementation in the diet of Nile tilapia (Oreochromis niloticus) fingerlings challenged by Streptococcus agalactiae.Fish were fed with experimental diets containing five levels of supplementation with 1.39%, 1.76%, 1.97%, 2.18% or 2.39% analysed level of ARG. Each diet was randomly distributed in 30 tanks containing 20 fish/tank. After 30 days, no differences were observed in performance parameters, weight gain, daily weight gain, specific growth rate, feed intake or food conversion. After the performance assay, fingerlings were infected with 1.95 × 10 8 CFU/fish of Streptococcus agalactiae. Mortality was verified daily, and the respiratory burst of leucocytes and nitric oxide production were measured at 0 hr, 24 hr, 7 days and 15 days after infection. The survival rate of the fish is compared using the Kaplan-Meier method, with values of 4.29%, 14.8%, 10.8%, 17.2% and 33.3% for the 1.39, 1.76, 1.97, 2.18 and 2.39 treatments respectively. A reduction in the mortality rate and a boost in the immune responses was observed in all the supplementations of ARG in the diet; however, the best survival rates were obtained in the treatments with 2.39% ARG as well as the most efficient immune responses.