Efectos de la suplementación con copra sobre la producción de leche, su composición y la concentración de metabolitos en plasma de ganado bovino doble propósito en pastoreo (Effects of the supplementation with copra on the production of milk, their composition and the concentration of metabolites in plasm of cows dual purpose in grazing)

Dry endosperm of the coconut named copra (C) it is an abundant resource in the coasts and for their high content of oil (65%) it constitutes a dense energy feed. In the coastal area of the State of Guerrero, Mexico, the coconut tree is cultivated under a system whose sustainability is threatened by the drop in the price of its oil, the risk exists of demolishing the palms that it would cause a deterioration of the coastal landscape and damage to the ecological environment. With the purpose of diversifying the use of C in the animal feeding, the experiment was developed to determine voluntary intake and responses of grassing dual purpose cows supplemented with three levels of C. Eighteen multiparous cows (86 DIM) were randomly assigned to one of three treatments: T1) 0% C, T2) 15% C y T3) 22.5% C. The supplements were isoproteic and 2 kg/cow were offered at milking time (07:00) which was performed manually. Milk weights were recorded daily. The experiment lasted 56 days (d) with the animals grazing insurgent grass (Brachiaria brizantha). Body weights were recorded and milk and blood samples were taken immediately after the morning milking at the beginning, every 14 d and at the end of the trial. Supplemental dry matter and crude protein (CP) intake were not different (P>.05). Crude fat (CF) intake increased in cows received (C) (200, 320 and 446 g/d for T1, T2 and T3, respectively). Supplemental C did not affect (P>.05) milk production, CF production, % CP and CP production (6.04, 6.03 and 6.15 kg/d; .239, .258 and .256 kg/d; 3.35, 3.24 and 3.21%; .202, .193 and .199, for T1, T2 and T3, respectively). However, it increased significantly (P <0.05) the% of G in milk (3.46, 4.30 and 4.27% for T1, T2 and T3 respectively). The plasma concentrations of triglycerides and free fatty acids were not affected by C supplementation. However, plasma cholesterol concentration tended to increase in weeks 7 and 8 of the experiment (P=.10) and (P=.07), respectively.