ABSTRACT This study aimed to evaluate the thermal response of three strains of hens housed in a cage-free system at the Amazon rainforest in order to evaluate how feather coverage influences thermal exchange with the environment. The experimental method was completely randomized and treatments comprised three strains of hens (Rhode Island Red (red feathers with feathers on the neck), alternative strain FCI (red feathers without feathers on the neck), and alternative strain FCIII (white feathers without feathers on the neck)), with 20 hens (replicates) analyzed per strain. Thermal images of each bird were captured in order to record the birds’ surface temperatures on five points in five targets. All data collected in this study were subjected to ANOVA and subsequently to the Tukey test at p≤0.01 and p≤0.05. The aviary’s left wall presented a lower average temperature, indicating lower heat accumulation, while the floor presented higher heat accumulation. FCIII hens (white feathers) presented higher (p<0.05) heat accumulation on the head and legs, and lower (p<0.05) heat accumulation on the neck and back in relation to other analyzed hens, indicating increased heat exchange efficiency and high concentration of this process in specific body areas. FCI and FCIII hens (without feathers on the neck) presented lower (p<0.05) heat accumulation on the neck and higher (p<0.05) heat accumulation on the head and legs, indicating that the feather coverage directly influenced heat exchange mechanisms, and an increased area without feathers provided great heat exchange zones for birds in a tropical climate.

ABSTRACT The objective of this study was to determine the ideal requirement of sodium to molted laying hens. The experimental period lasted 105 days, divided into five periods of 21 days. Hisex White laying hens 150 with 84 weeks-of-age were used. The experimental design was completely randomized in a factorial scheme (5x3) with treatments constituted by five levels of sodium (0.10, 0.15, 0.20, 0.25, and 0.30%) in the diets, and three postmolt stages (early = 21 days, medium = 63 days, and final = 105 days). Performance and egg quality results were evaluated by Tukey test at 5%. Eggshell resistance and weight gain results were evaluated by polynomial regression at 5%. Except the yolk height, all performance and egg quality variables were affected (p<0.05) by the sodium levels and the hens’ age postmolt. The level of 0.15% of sodium in diets to postmolt laying hens provided better performance and egg quality, especially in the eggshell. Higher levels of sodium negatively affected the performance and egg quality. Hens in the early stage of postmolt period presented better performance and egg quality. At long-term, the postmolt hens presented worst results.

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 The present study aimed to evaluate ducks on performance, carcass traits and economic availability, fed on different phases of nutritional plans and in different housing densities. 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 in a factorial arrangement of 3x2 with three nutritional plans (3, 4 and 5 phases) and two housing densities (2 and 3 birds/m2) with four replicates. The ducks had weekly performance evaluations, and after 90 days, four birds in each treatment were slaughtered for evaluation of carcass traits. Differences (p<0.05) were observed on performance, carcass traits and economic analysis. The nutritional plans with 3 phases showed better results for feed intake and weight gain, as well as provided lower total cost production and higher operating profit. Ducks in higher densities showed smaller feed intake, weight gain, higher pro-ventricle weight and better results for total meet production, crude income and operating profit. In summary, nutritional plans with reduced phases (3 phases) and extensions of energy-protein relationships showed better results for ducks on performance and carcass traits in densities of 3 birds/m². More studies are necessary to determine other nutritional requirements for ducks in housing for a better nutritional and management control.