Effect of sex and of the supplementation with a probiotic on the liveweight gain of weaned calves fed integral rations based on ground hay. Technical note

Resumen

Twenty-four weaned calves (12 females and 12 males) with general average weight of 116 kg were used in a random block design with factorial fit to study the effect of sex and of supplementation with a probiotic (Sorbial) on the liveweight gain. The animals were given an integral ration with 40 % ground grass hay. The experiment lasted 111 d. The general liveweight gain was of 0.77 kg/d. There was no effect of the probiotic on the liveweight gain. The males had a liveweight gain higher (0.837 kg/d) than that of the females (0.706 kg/d). The weight gain of the females was sufficiently high so as to be considered in the design of feeding systems of female weaned calves. It is concluded that the feeding system with integral ration similar to the one used in this experiment is a promising alternative for the feeding of female calves. Besides, the supplementation with a probiotic does not seem to be necessary, at least, as to the liveweight gain, always guaranteeing the adequate hygiene and care conditions. Further experiments are suggested at larger scale to draw definitive conclusions.
Key words: probiotic, integral rations, weaned calves.