ABSTRACT The objective of this study was to evaluate the effect of storage time on albumen quality, incubation yield, and hatch window in Pekin ducks (Anas boschas). A total of 1302 eggs were randomly distributed to seven treatments according to the storage time with durations ranging from 1 to 14 days. Each treatment consisted of 186 eggs with a two-day storage interval between treatments. The pH and Haugh unit (HU) of the albumen, egg weight loss during incubation (WL), hatchability (HTCH), incubation duration (ID), hatch window, asymmetry (ASS), percentile kurtosis (PK), and embryonic mortality were analyzed. A linear effect was observed forthe WL, ID, and PK and a quadratic effect forpH, HU, and HTCH over time. No significant effect of storage time was observed on ASS. Post-pipping embryonic mortality was linearly affected by storage time. Prolonging the storage period above 10 days reduces albumen quality and hatchability, delays the hatch of Pekins, and results in a higher percentage of post-pipping mortality.

ABSTRACT The experiment was conducted to study the effect of pure glycerin supplementation (GLYC) in the drinking water of broilers subjected to heat stress and feed restriction. Water with 0, 1, or 2% glycerin was provided ad libitum to broilers in six hours of feed restriction. The birds were housed in two environments: thermoneutral (TN) - 25 ° C, and cyclic heat stress (HS) - 12h with 250C, 6h with 320C, 3h of 250 to 320C and 3h of 320 to 250C. The experimental design was randomized in a factorial arrangement of 2 x 3 + 2, with three GLYC levels, two environments and one control group with ad libitum feeding each environment. When submitted to HS, broiler receiving 2% glycerin presented higher weight gain (WG), water consumption (WC), feed intake (FI) and energy consumption (EI) than those in the other treatments, contrarily to birds in TN, where increasing GLYC levels decreased those responses. Broilers submitted to feed restriction presented reduced FI, but better feed conversion (FCR), independently of rearing environment or GLYC levels. Broilers under HS submitted to feed restriction and receiving 2% GLYC presented higher WC (p< 0.05) and similar WG as the controls, differently from the restricted-fed broilers under TN receiving 2% GLYC, which WC and WG were lower than the controls. The inclusion of 2% pure glycerin in the drinking water may compensate the negative effects on performance caused by feed restriction in broilers submitted to heat stress.