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 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.