Abstract

AVENDANO, L. et al. Feeding frequency and night lighting and feedlot heifers performance during summer. Arch. zootec. [online]. 2011, vol.60, n.232, pp.1247-1254. ISSN 1885-4494.  https://dx.doi.org/10.4321/S0004-05922011000400039.

The combined effect of increasing feeding frequency and night lighting on feedlot performance and carcass traits during summer was studied in 171 beef heifers. Treatments were: two rations daily (control group) and three rations daily (treated group), during a feedlot period of 84 days. Heifers received the same diets. Treated heifers were 16 kg heavier (p<0.05), had higher daily gain (0.140 kg d^-1; p<0.05), and better feed conversion (7.69 vs. 8.69 dg d^-1; p<0.05) than control heifers, although feed intake was similar. Control heifers showed higher (p<0.05) respiration rate than treated (93.5 vs. 83.9 breaths min^-1), which suggests higher level of heat stress in those animals. Hot carcass weight was higher (p<0.05) in treated heifers than in control (244.3 vs. 233.9 kg); however, there were no differences in the other carcass traits. These results suggest that increasing feeding frequency and photoperiod during summer may improve feedlot performance and adaptation to high temperatures in beef heifers.

Keywords : Heat stress; Productive performance.

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