Alves et al., 2010. Rev. Bras. Zootec., 39 (3): 532-540
Substituicao do farelo de soja por farelo de algodao de alta energia em dietas para vacas leiteiras em producao: consumo, digestibilidade dos nutrientes, balanco de nitrogenio e producao leiteira
The effect of replacing increasing levels of high-energy cottonseed meal (0, 8.7, 17.4, 26.1 and 34,8% DM) with soybean meal in concentrate for cows in the final lactation third on intake, nutrient digestibility, nitrogen efficiency and milk yield was assessed. Five crossbred 5/8 Holstein × 3/8 Gir cows were allotted to a 5 × 5 Latin square design, with five 18-day periods (eight days for adaptation and 10 days to determine intake and collect samples). The diets were formulated to have similar protein contents (14% CP), with 60% corn silage and 40% on the DM. There was no effect of including high energy cottonseed meal on the intakes of DM, organic matter (OM), crude protein (CP), total carbohydrates (TCHO) and total digestible nutrients). The EE intake increased with levels of 26.1 and 34.8% of high energy cottonseed meal inclusion, while the non-fibrous carbohydrate (NFC) intake was higher for levels of 0, 8.7 and 26.1%. The digestibility coefficients of the nutrients did not differ among the high energy cottonseed meal levels experimental diets. Replacing soybean hulls levels with high energy cottonseed meal did not influence the nitrogen use efficiency or balance, or the milk urea nitrogen content (MUN) and blood urea nitrogen (BUN). Average milk yield (14.03 kg/day) and milk yield corrected for 3.5% fat milk fat (14.68 kg/day) were not influenced by the different levels of high-energy cottonseed meal in the diet and there was no difference for feed efficiency. High-energy cottonseed meal presents potential for replacing soybean meal in the diet of cows with 15 kg/day production capacity.