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.

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.

The objective was to evaluate the productive performance, apparent digestibility of the diet and ingestive behavior of beef cattle finished in feedlot under the effect of the inclusion of yeast culture or enzyme complex. The treatments were: diet without additives (control); diet with enzyme complex (7 g animal day-1); diet with yeast culture (7g animal day-1) and diet with the association of enzymatic complex (7 g animal day-1) and yeast culture (7g animal day-1). The experimental design was completely randomized, with five replications. Forty ½ Angus ½ Nellore steers, with an average initial body weight of 362 kg ± 6 kg, were used. Regardless of the evaluation period, non-supplementation caused the animals to gain less weight (0 to 21 days: 1.267 kg day-1; 0 to 42 days: 1.377 kg day-1; 0 to 63 days: 1.368 kg day-1) compared to supplemented animals, feed conversion for non-supplemented animals was also worse. Starch apparent digestibility showed higher averages when steers were supplemented with yeast culture alone and yeast culture combined with enzyme complex (97.30% and 97.07%, respectively). Supplementation using a combination of yeast culture with enzyme complex did not cause additional effects on weight gain, but resulted in the lowest averages for feed conversion.