BEEF POTENTIAL PRODUCTION, GRAZING Brachiaria PASTURES ALONE OR ASSOCIATED WITH Arachis pintoi LEGUME. 1994-1996.

Abstract

The work was done for three years (1994-1996) at the Experimental Station of Gualaca with the objective of generating information about grazing performance of Brachiaria pasture in terms of availability of dry matter, quality pastures and beef production. Evaluated pastures were: Brachiaria decumbens cv. señal and Brachiaria dictyoneura cv. Gualaca, associated with the legume known as “Forage Peanut” (Arachis pintoi CIAT-17434) (Bde + Ap y Bdi + Ap), respectively. B. decumbens was fertilized with 80 kg N/ha/year and B. dictyoneura with 50 kg N/ha/year Bde + N and Bdi + N); and both pasture without nitrogen fertilization (Bde – N and Bdi – N). Associated and fertilized with N pastures received 30 and 20 Kg/ha of P₂O₅ y K₂O, additionally, associated pastures received 20 and 20 kg/ha of Mg and S, respectively. It was used a Completely Randomized Block Design with two replications. Grazing was alternated with occupation/resting periods of 28/28 days, stocking rate of 3 and 4 steers/ha of 225 kg LW for B. decumbens and B. dictyoneura during dry and raining season, respectively. Stocking rate was adjusted according with the variation of the forage, depending of the season of the year. There was no significant differences (P>0.01) in forage availability of the pastures; season and pastures by season possibly due to this was regulated by stocking rate which was of 3.35 to 2.77 and from 2.73 to 1.79 AU/ha during raining and dry season for B. dictyoneura and B. decumbens, respectively. B. dictyoneura was superior in forage availability (1,581 kg DM/ha/grazing cycle) to B. decumbens (1,351 kg DM/ha/grazing cycle). Forage quality was lightly superior in Bdi + Ap and Bde + Ap, respect to the remain pastures. Besides, B. decumbens showed superiority (P<0.05) in PC and DMDIV quality in relation to B. dictyoneura. B. decumbens pastures showed highly significantly (P<0.01) better weight gain (512 g/animal/d) respect to B. dictyoneura (421 g/animal/d). Obtained increment on the animal daily gain in associated Brachiaria with Arachis pintoi over Brachiaria alone without or with nitrogen fertilization was 49 and 21 percent, respectively. It was observed better beef production per hectare in associated Brachiaria with Arachis pintoi (1,031 and 721 kg in B. dictyoneura and B. decumbens, respectively). Feeding time in order to obtain animals with live weight at slaughter from different pastures of Brachiaria were of 14.1, 15.9, 19.3, 12.5, 15.0 and 18.5 months of age for Bdi + Ap; Bdi + N; Bdi – N; Bde + Ap; Bde + N and Bde – N, respectively. Low production costs per kilogram of meat and higher profitability were with pastures of Bdi + Ap and Bde + Ap ($ 0.56 and 28% and $ 0.59 and 29%, respectively). It was concluded that pastures of Brachiaria associated with Arachis pintoi can reach higher production and productivity level over Brachiaria alone without fertilized and fertilized Brachiaria alone with 80 kg N/ha/year under Gualaca, Panama condition.