Equilíbrio nutricional das vacas leiteiras em alta produção pastando em sistemas silvipastoris intensivos

Montoya, Elisa SierraChará, Julian DavidBarahona-Rosales, Rolando

A study was carried out to estimate the balance of metabolizable protein (MP), metabolizable energy (ME), calcium, and phosphorus in 12 recently calved (RC) and early lactation (EL, 42 – 50 days after calving) Gyr x Holstein dairy cows grazing in a Leucaena leucocephala and Cynodon plectostachyus intensive silvopastoral system (ISS) and receiving energy and protein supplementation. Dry matter (DM) availability from the grazing paddocks, nutrients offered and their balance were estimated. On average, the available forage DM per animal.day-1 was 44.7 kg for C. plectostachyus and 11.8 kg for L. leucocephala. EL cows had greater requirements of MP, ME, and minerals than RC cows. In RC cows, ME, MP, and mineral requirements were supplied by the total diet, while EL cows exhibited a negative energy balance. For both RC and EL cows, ME was the limiting dietary factor, whereas MP and P were found to be in excess. If cows were only to receive ISS forages with no supplementation, estimated daily milk yield would be 10 and 12 litters for RC and EL cows, respectively. Under tropical conditions, based on ISS forage intake, RC and EL cows can meet most of their ME, MP, calcium, and phosphorous requirements.(AU)

1. protein balance
2. balanço de energia
3. energy balance
4. necessidades de nutrientes
5. nutrient requirements
6. balanço da proteína
7. phosphorus balance
8. Leucaena leucocephala
9. balanço de fósforo