Un equipo de investigación del INTA evaluó la sustentabilidad de estrategias para controlar la garrapata común del bovino Rhipicephalus (Boophilus) microplus, uno de los parásitos con mayor impacto en la producción ganadera en áreas tropicales y subtropicales del mundo, incluyendo la Argentina.
Trabajos en Prensa
Substitution of sunflower meal for soybeans in the diet on performance and beef characteristics of feedlot steers
Two experiments were conducted to determine the effects of inclusion (Level: 0, 8, 16 and 24% on DM basis), processing (Grnd: whole or ground) and thermal treatment (Roast: raw vs roasted) of soybeans substituting for sunflower meal, on performance and carcass traits of pen-fed steers. Experiment 1 explored responses to Level and Grnd. Experiment 2 explored responses to Level and Roast. For Experiment 1, 96 Angus steers (210 ± 14.50 kg) were distributed randomly in 24 pens with 4 per pen. For Experiment 2, 96 Angus steers (280 ± 18.50 kg) were distributed into 32 pens with 3 per pen. Diets were based on corn grain, sunflower meal, urea, hay and a mineral/vitamin premix, with soybeans added according to Level. Variables determined were: live weight (LW), LW gain (LWG), dry matter intake (DMI), DMI relative to LW (DMILW), feed efficiency (FE), hot carcass yield (HCY), rib eye area (REA) of the longissimus thoracis section and back fat thickness (BFT). Data of each experiment were analyzed in a 4 x 2 factorial completely randomized design. Pens were the experimental units. Effects of Level were separated by Tukey; effects of Grnd and Roast by significance of F test. For both experiments, inclusion of 24% raw soybeans depressed (P < 0,05) final LW, LWG, DMI, DMILW and worsened FE, compared with the other levels. Level 24 also reduced (P < 0,05) RRes and BFT in experiment 1. No interactions (P ≥ 0,37) between Level and Grnd and no effects (P ≥ 0.39) of Grnd were detected. Level interacted with Roast (P < 0.01). Roasting removed the depressing effects of Level 24 on animal performance. Substituting sunflower meal for raw soybeans up to 16% of the diet, or roasted across at levels, did not (P > 0,05) affect performance and carcass variables.
Keywords: soybeans, raw soybeans, heat-treated soybean, growth variables, carcass characteristics.
1 Instituto Nacional de Tecnología Agropecuaria (INTA), Estación Experimental Agropecuaria (EEA) Anguil, Ruta Nacional 5 km 580 (6326) Anguil, La Pampa. Correo electrónico: email@example.com
2 Universidad Nacional de La Pampa (UNLPam), Facultad de Ciencias Veterinarias, La Pampa.