Ingestive behavior of calves fed diets based on corn grain and supplementary hay / Comportamento ingestivo de bezerros alimentados com dietas a base de milho grão inteiro e feno suplementar

Abstract

In this work, the influence of the addition of Tifton-85 hay supplement to the corn grain mix and commercial pellet was assessed in terms of the digestive behavior exhibited by the dairy calves. The Latin square 4 x 4 duplicate and simultaneous design was adopted in this experiment, in which the treatments included four levels of the hay supplement Tifton-85 (0, 0.2, 0.4, and 0.8 %) with respect to body weight, in the corn grain mix and commercial pellet, over four experimental periods, with two repetitions (eight animals). The effect of the hay levels (P < 0.05) was evident in the time taken by the animals for feeding (TFE), rumination (TRU), and total chewing time (TCT), however, the time spent in leisure (TO) remained unaffected (P > 0.05). The variables, chew time per bolus (CT/bolus), and number of chews per bolus (NC/bolus) showed no differences among the treatments (P > 0.05), however, the number of chews per day (NC/day), and number of ruminal boluses (NRB) revealed significant variations (P < 0.05). Among the treatments, the effects on feed efficiency (EFDM) and rumination (ERUDM) of dry matter (P < 0.05) were evident, but the rumination efficiency of the neutral detergent fiber (ERUNDF), and rumination rate (RR) were not affected (P > 0.05). The supplementary levels of hay added to the diet increased the rumination and chewing times.