Asociación Latinoamericana de Producción Animal (ALPA)
Abstract
The response in growth and carcass quality of 102 intact and 20 castrate males grazing dry season followed by irrigated dry season native (Lambedora) improved (Tanner grass) forages to selected strategic technologies was investigated. The key is to develop strategies to deliver these technologies in ways that will enhance fermentative rate and efficiency to allow greater intake and animal productivity. Nutritional strategies included 1) a macro/tracemineral supplement (MIN) or 2) a strategic (STRAT) supplement including key minerals, a slowly degrading protein source (feather meal) to provide a continuous nitrogen release, ionophore (Salocin), degradable fiber (rice polishings), and capsulized fat (whole cottonseed). Cattle initially were intensively grazed on flood and pump irrigated pastures until target weight (average 495 kg) and condition were achieved. Cattle were implanted initially with zeranol (72 mg) or Revalor followed by a second implant of zeranol (72 mg). Mineral supplement for MIN cattle was provided continuously and STRAT (comprised of feather meal, whole cottonseed, molasses, rice polishings, mineral mix and Salocin at 10, 0, 5, 77.9, 7, and 1 % for d 0-60 and 10, 49.9, 5, 28, 7, and 1 % for d 61-182), was hand-fed at 1 kg/hd daily. Total MIN or STRAT consumption was 15.3 vs. 172 kg/hd or 84 vs. 945 g/d through d 182. At 182 d, the first group was selected for slaughter and supplementation with STRAT was ceased. At this point, the MIN and STRAT cattle averaged 459.4 and 487.2 kg and differed (P<.001) in weight. Average daily gain to 182 d averaged 676 vs. 818 g (P<.001), for a 142 g/d response. Further, the STRAT supplement enhanced (P<.001) dressing percentage from 57.6 to 59.0 % at termination, and adjustment of d 182 response to a common dressing percentage yielded a 32.6 kg response in weight or 179 g response in daily gain
