Acta Scientiarum: Animal Sciences (Apr 2008)
Orientação e sombreamento do confinamento na temperatura da superfície do pelame de bovinos = Effect of feedlot orientation and shading on haircoat surface temperature of cattle
Abstract
Avaliou-se o efeito do sombreamento sobre a temperatura da superfície do pelame (TSP) de bovinos de cinco grupos genéticos, 4 ½ Limousin + ½ Nelore (L), 8 ½ Limousin + ¼ Nelore + ¼ RedAngus (LR), 4 ½ Limousin + ¼ Nelore + ¼ Simental (LS), 2 ½ Marchigiana + ¼ Nelore + ¼ Simental (MS) e 4 ¾ RedAngus + ¼ Nelore + ¼ Guzerá (RG), com 20 meses de idade e peso médio de 300 kg, alojados em baias individuais de 10 m2, sendo metade coberta com telhas de zinco. A dieta era isoproteica e isoenergética com relação volumoso:concentrado 67:33. A TSP do Lado 1 (L1) do confinamento, durante o dia, não diferenciou (p > 0,05) entre os grupos genéticos, enquanto que para o Lado 2 (L2), a menor média (29,48oC) (p 0,05) entre os demais. No L2, a maior TSP (p The study evaluated the effect of shading on haircoat surfacetemperature (HST) of cattle from five genetic groups: 4 ½ Limousin + ½ Nellore (L), 8 ½ Limousin + ¼ Nellore + ¼ RedAngus (LR), 4 ½ Limousin + ¼ Nellore + ¼ Simmental (LS), 2 ½ Marchigiana + ¼ Nellore + ¼ Simmental (MS) and 4 ¾ RedAngus + ¼ Nellore + ¼ Guzerá (RG). The cattle were 20 months old and had an average weight of 300 kg.They were housed at individual 10 m2-pens, with half covered with zinc tiles. The diet was isoproteic and isoenergetic, with a 67:33 roughage concentrate ratio. There was no difference (p > 0.05) in HST among genetic groups during daytime on Side 1 (S1) of thefeedlot, while on Side 2 (S2) the lowest HST (29.48oC) (p 0.05) among the others. On Side 2, the highest HST (p < 0.05) occurred for RG (30.63oC) and the lowest (p < 0.05) for MS (28.07oC). The building orientation showed no effect on HST of animals, which was influenced by time of day, direct reflex action of thermal radiation intensity on zinc tiles and on the concrete floor.
