PRODUCTIVE AND ECONOMIC EVALUATION OF THE INCLUSION OF OAT (Avena sativa L.) STRAW AND PASTURE SILAGE IN THE DIET OF FINISHING STEERS

Abstract

Cereal straw is a feed alternative for cattle used to maintain animal weight during the winter and fall period. The objective of this study was to evaluate animal response of finishing steers to a winter feeding system using oats straw or pasture silage. Twenty-eight Hereford x A. Angus steers of 22-23 months of age and 328 ± 6 kg initial live weight were used in the following treatments: T1: pasture silage plus lupine and oat grains; T2: oat straw plus lupine and oat grains; T3: oat straw plus lupine and barley grains; and T4: oat straw plus lupine and triticale grains. Isoproteic and isoenergetic diets were formulated for a minimal liveweight gain of 1.0 kg d-1 and the experimental period lasted 70 days. Daily live weight gains were 1.320 a; 1.059 b; 1.276 a and 1.102 b kg head-1 (P ? 0.05); daily intake was 8.72; 8.61; 8.53; and 8.07 kg DM head-1, while feed conversion ratio was 6.60; 8.13; 6.68; and 7.32 kg DM consumption per kg of live weight gain for treatments 1, 2 ,3 and 4, respectively. Dressing percentage and ribeye area did not present significant differences (P ? 0.05). It was concluded that finishing diets with oat straw did not affect the productive response of steers when barley was the grain used. It was also determined that the diet with the lowest cost per kg consumed and kg of live weight gain was pasture silage.