UTILIZATION OF Arachis pintoi BANK AS A PROTEIN SOURCE IN A PARTIAL FEEDLOT SYSTEM OF FINISHING STEERS. 2. TOTAL SUBSTITUTION OF THE PROTEIN FROM FISH MEAL BY PROTEIN FROM Arachis pintoi.

Abstract

Using a partial feedlot system of finishing steers it was evaluated the total substitution of the fish meal crude protein of a supplementary feed for Arachis pintoi as a protein bank. It was used a complete randomized design with two treatments: 100.0 (THP) and 0.0 (TAP) % fish meal in the suplementary feed. The partial feedlot system consisted of grazing in a mixture of Brachiaria decumbens and Dactylon mlenfuensis during 3 to 4 hours in the morning (3/21days rotation system, 8.5 AU/ha of initial stoking rate and fertilization) and complete feedlot during the rest of the day with a supplementary feed. The protein bank was grazed daily for one hour with an initial stoking rate of 18.9 AU/ha in a 30/30 days occupation system and fertilization. The supplementary feed was composed by molasses, urea, fish meal, corn grain, mineral mixture and sodic lasalocid. The dry matter (DM), metabilizable energy (ME) and crude protein (CP) intake were different (P<0.002) between treatments, 9.1, 8.3 and 36.9% less for TAP. The CP intake of fish meal was 0.082 kg/100 kg of life body weight/day. In the grass the stocking rate (ST) was not different between treatments (P>0.90), but the offer DM avialability (DMA) and the numerical value of grazing pressure (GP) were greater for TAP (P<0.01). In the protein bank, DMA, GP and legume intake decreased and SR increased with time, with mean value of 1942 kg/ha, and 0.31 and 0.43 kg/100 kg of life body weight/day and 27.6 AU/ha, respectively. The mean value of replacement of fish meal CP for A. pintoi CP was 81.6%. The body weight gain was higher for THP than for TAP (P<0.032), 1.220 and 1.045 kg/animal/day. However, the A. pintoi reduced in 26.0% the feed cost and improved the economical utility in $ 0.244/animal/day.