Caracterización energética y proteica de materias primas de origen animal empleadas en la formulación de alimentos balanceados para vacas lecheras.

Abstract

Energetic and proteic characterization of prime sources of animal origin used in the formulation of a balanced feed for dairy cattle. The kinetics of ruminal degradation of dry matter, crude protein and ether extract were determined for fish, meat and bone, and poultry meals. These meals of animal origin showed characteristics proper of the species of origin, not only in the soluble fraction but also in the rates of ruminal degradability of the potentially degradable fraction. Based on the results of degradation after 48 hours of ruminal incubation, the true digestible contents of the protein and the digested ether extract were determined biologically, making the measurement of the total digestible nutrients, and the concentration and net rate of digestible energy and feed, more precise than determinations by chemical methods. The concentrations of energy for milk production was 2.02, 1.66, and 2.60 Mcals/kg for fish, meat and bone, and poultry meals, respectively. The fraction of soluble protein (A) was high in fish meal (75.29%), intermediate in meat and bone (46.83%), and low in poultry (25.75%), with a degradable fraction (B) of 10.62, 27.66, and 42.06%, along with an insoluble fraction (C) of 14.09, 25.51, and 32.19%, respectively. The degraded protein in the rumen was 83.23, 66.25, and 51.98% in the same order cited above. The contents of crude protein effectively retained by the animals during the whole digestive process were 53.29, 51.86, and 42.05% for fish, meat and bone and poultry meals, respectively.