Destete precoz de becerras bajo condiciones desfavorables: El uso de varios niveles de heno de alfalfa

Abstract

Three groups involving 22 females Holstein calves were used to compare different systems of alfalfa hay feeding. Following abrupt weaning at 28 days of age, one group received ad libitum amounts of a basal ration having the following composition. Cottonseed meal 10 per cent, soya bean meal 20 per cent ground sorghum grain 49 per cent, molasses 10 per cent, maize 10 per cent, tri-calcium phosphate 0.5 per cent, salt 0.5 per cent, Vit A. 5,000 kg., Aureomycin 0.2 g/kg. The second group of calves received ad libitum levels of the basal ratio which had been modified by substituting 5 per cent ground alfalfa hay for 5 per cent sorghum grain. The third group was treated as the first group plus medium-quality alfalfa hay fed free choice. Body weight, height at the withers, thoracic perimeter, cannon-bone perimeter, body length, and consumption of the diets were determined weekly until each calf had reached an age of 14 weeks. No statistical differences in growth measurements could be demonstrated amongst groups, although that which received no alfalfa gained more weight than the other groups. Food conversion efficiency was significantly poorer for the animals fed alfalfa hay ad libitum. Also, both groups that received alfalfa hay consumed significantly less concentrate than the control group. An economic evaluation of the data indicated that free-choice alfalfa was not to be recommended under the conditions normally prevailing in the area.