Terminação de machos de origem leiteira com dietas de milho ou milheto, inteiro ou moído

Abstract

The objective was to evaluate the effect of substitution of corn grain by pearl millet, ground or whole, on intake, digestibility, performance, blood parameters, economic evaluation and feeding behavior young bulls of dairy origin finished in feedlot. We used 28 young bulls of dairy origin with average initial weight of 262.70 ± 26.04 kg, distributed in a completely randomized design with a 2 x 2 factorial arrangement, with seven replicates per treatment. We evaluated four experimental diets containing two types of grains (corn x pearl millet) and two forms of processing of the grains (ground x whole). The dry matter (DMI), crude protein (CPI) (P=0.059), ether extract (EEI) and non-fiber carbohydrates (NFCI) had interaction (P<0.05) among the factors evaluated. The whole millet diet increased the DMI (% PV), EEI and NFCI compared to ground pearl millet. The grain whole millet increased DMI, CPI, EEI and NFCI compared to whole corn grain. Replacing corn grain by grain millet reduces the apparent digestibility coefficients of ether extract (EEADC), non-fibrous carbohydrates (NFCAD) and total digestible nutrients (TDN) (P<0.05). The processing of grain increases the apparent digestibility coefficients dry matter and nutrients (P<0.05), except for NDF (P>0.05). There was interaction between the factors (P<0.05) for the concentration of alkaline phosphatase, which was lower for the whole millet diet compared to other evaluated diets. The final weight, total weight gain and average daily gain were similar regardless of the types (P>0.05) and the processing of grains (P>0.05). The evaluated factors do not alter the gross revenue (P>0.05), but modified net revenue (P<0.05), which was lower for the whole pearl millet diet compared to other evaluated diets. The food and rumination times have not changed in response to the type (P>0.05) or the processing of grains (P>0.05). On the other hand, the idle time is greater for animals fed corn (P<0.05) and time of other activities it greater for pearl millet diet (P<0.05). There was an interaction (P<0.05) among the factors evaluated on the number and duration of rumination chews per bolus, which were higher for the whole pearl millet diet. Thus, the grain of pearl millet can replace corn grain in the diet of dairy male in confinement for promoting similar performance. However, pearl millet grains should be provided ground, due to increased availability energy promoted by processing resulting in increased feed efficiency and economic return of activity.