Abstract

BERNARDI, José Reinaldo de Amorim; ALVES, João Batista  and  MARIN, Camila Motta. Performance of lambs under four production systems. R. Bras. Zootec. [online]. 2005, vol.34, n.4, pp. 1248-1255. ISSN 1806-9290.  http://dx.doi.org/10.1590/S1516-35982005000400021.

Forty singletons crossbred Texel lambs were assigned to four treatments to compare their performance in either feedlot or at pasture, with or without supplementation. In the first treatment ("Min"), the lambs received a mineral supplementation and stayed with their mothers up to 105 days old in a paddock of Panicum maximum cv. Colonião but only the lambs had access to the supplement. The second treatment ("Prot") differed from the fist one only in that the lambs were supplemented with protein salt rather than mineral salt. In both third ("Creep") and fourth ("Feedlot") treatments the lambs had access to creep feeding but at 60 days of age animals from the fourth treatment were weaned and finished in feedlot until they reached 105 days of age. Comparisons among treatments were done by contrasts and F-test. Males gained more weight than the females counterparts from 21 days old until completion of the trial. Lambs on Creep and Feedlot treatments had better performance than those on Min and Prot supplementation. At 105 days of age, the average weights of the males were: 36.98 kg (Feedlot), 34.16 (Creep), 32.14 kg (Prot), and 30.24 kg (Min). Lambs on Creep and Feedlot treatments reached their finish weight (from 28 to 32 kg) at 84 days of age. No significant difference on performance was observed between "Min" and "Prot" treatments in the current study. It can be concluded that production of lambs at pasture was not compromised under the conditions of this trial.

Keywords : confinement; weight gain; pasture.