ABSTRACT The present study aimed to determine ideal levels of available phosphorus for muscovy ducks in housing. Two hundred and forty muscovy ducks of creole lineage were used, distributed in boxes with water and food ad libitum. The experimental design was completely randomized with treatments consisting of six nutritional plans that included the initial, growth and termination phases and differed in relation to available phosphorus levels, and four replicates of 10 muscovy ducks each. The birds had weekly performance evaluations, and after 90 days, eight birds (four males and four females) in each treatment were slaughtered for evaluation of carcass traits. Data collected were subjected to Tukey test at 5% of significance. Differences were not observed (p>0.05) in performance. Higher available phosphorus levels presented a positive influence (p<0.05) on carcass. Results presented differences (p<0.05) among sexes for carcass development and commercial cuts, with better feed efficiency of males than females in same period. For mineral composition, differences (p<0.05) were observed to calcium (%), phosphorus (%) and Ca:Pratio. The present study indicates that nutritional plan 2 (initial = 0.60%; growth = 0.55% and termination = 0.50%) presented ideal nutritional requirement of available phosphorus for muscovy ducks in housing, with better carcass development and mineral deposition on bones.

ABSTRACT In ovo feeding (IOF), injecting nutrients into the amnion of the avian embryo may enhance hatchability, gastrointestinal development and serum metabolism changes. This hypothesis was evaluated with 5 IOF solutions containing L-glutamine. Were used 315 fertile Rhode Island Red eggs were used (breeders with 32-weeks). The experimental design was completely randomized with the treatments constituted by two controls and five solutions containing L-glutamine levels with 45 replicates each. Data collected were subjected to polynomial regression at 5% of significance. Differences (p>0.05) were observed in hatchability and intermediary mortality, with a gradual lower of decrease in hatchability from the IOF of L-glutamine. The yolk sac was higher (p<0.05) after the IOF (control and L-glutamine) in the in ovo fed embryos at 0.5% L-glutamine. IOF of L-glutamine alone enhanced the blood pH and reduced the other serum parameters (p<0.05), which may have fuelled more embryo development, mainly vital organs how as the heart and the liver due to the larger concentration of available nutrients for the embryo. The results of this study indicate that until 0.5% L-glutamine may be supplemented in-ovo to chick embryos without negative influence on chick weight and gastrointestinal tract development, acting as serum biochemical metabolism regulator and obtaining better hatchability.

ABSTRACT The present study aimed to evaluate increasing levels of fish waste oil in laying hens diets on performance, egg quality, and sensory features of the eggs. 192 Hisex White laying hens with 29 weeks of age were used, with water and food ad libitum. The experimental design was completely randomized consisting of eight treatments corresponding to the inclusion levels of fish waste oil (0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 and 3.5%) in the diets, with four replicates of six birds each. Data collected were subjected to polynomial regression at 5% of significance. Differences (p<0.05) were observed in feed intake and egg mass. Feed intake increased until 2.50% of fish waste oil in the diets. Differences were not observed (p>0.05) in all variables analyzed. Differences were observed (p<0.05) in flavor. Eggs from birds fed diets up to 2.00% present better acceptance by the tasters. Above this level, there was a considerable drop in acceptance. From these results, the present study indicates that the use of fish waste oilin laying hens diets did not affect the egg quality. However, its high inclusion negatively affected the feed intake, egg mass, and egg flavor.

ABSTRACT This study aimed at evaluating the effects of the physicochemical and nutritional characteristics of a biological silage meal made of tambaqui waste on dietary nutrient apparent digestibility and energy metabolism of commercial layer diets. Seventy-two 61-week-old Hisex White hens were assigned according to a completely randomized experimental design in two treatments: control diet and diet with 5% tambaqui waste biological silage meal (TWBSM), with six replicates of six birds each. The ensiled biomass presented grey brown color, acid aroma, viscous texture, 5.27±0.016pH, 96.28% dry matter (DM), 33.29% crude protein (CP), 33.65% ether extract (EE), 14.37% ashes, 13.63% non-nitrogen extract (NNE), 65.16 g.kg-1 calcium (Ca), 22.90 g.kg-1 phosphorus (P), and 5,666.07 kcal.kg-1 gross energy (GE). Higher (p>0.05) coefficients of apparent digestibility of DM, crude fiber, EE, and ash, and higher coefficient of GE metabolizability were obtained in the diet with 5% TWBSM. Due to its high CP content (33.29% on DM basis), TWBSM may be considered a protein feedstuff. Although no differences in CP digestibility (p>0.05) were detected, TWBSM presented high CP digestibility than the control diet due to proteins hydrolysis as a result of lactic fermentation by microorganisms during the ensilage process, yielding autolysed proteins of high biological value. Our results indicate that the biological silage meal produced from the residual biomass of tambaqui can be included up to 5% in commercial layer diets as it has good nutrient digestibility, and therefore, may potentially be used as a dietary energy and protein source.