Características qualitativas da carcaça e morfometria do lombo (Longíssimus lumborum) de borregos Santa Inês terminados em pastagem e suplementados com concentrado

Abstract

The effect of different levels of concentrate supplementation on carcass qualitative traits and loin morphology (Longissimus lumborum) of lambs was evaluated. The experimental trial was performed in Setor de Ovinocaprinocultura, from Universidade Tecnológica Federal do Paraná, Câmpus Dois Vizinhos, with 18 lambs Santa Ines half bred finished in (Panicum maximum Jacq), Aruana grass pastures supplemented with concentrate (18% CP and 70% TDN), supplied twice a day at 8 AM and 5 PM, in collective stalls, distributed according to the different treatments (1.25%, 2.50% and 3.75% of body weight, dry matter based). Animals were randomly distributed within three treatments with six replicates each. After achieving preestablished weight of 40 kg, lambs were slaughtered. After refrigeration period, carcasses were submitted to the following subjective evaluations: conformation grade, fat cover, color and consistency of fat, and color of meat. Then, carcasses were sectioned in half and the loins were separated for the measurements of length and width of muscle, maximum and minimum fat thickness, loin eye area and, at the end of those evaluations, dissection was performed in order to obtain the bone: muscle:fat:connective tissue rate. Different levels of concentrate supplementation influenced (P<0.05) the qualitative traits of carcasses, with the lowest level of supplementation presenting the lower results. The variables loin eye area and length and width of loin were not significantly different (P>0.05), with the following mean values 12.64cm2, 57.97mm and 27.64mm, respectively. Fat thickness was influenced (P>0.05) by the concentrate supplementation, with higher values obtained by the highest level of supplementation. Concerning the tissue composition of loin, only the connective tissues presented significant difference (P>0.05), with higher values from the intermediate supplementation (2.50%), other variables presented the following mean values: loin 1,042g, bone 213g, muscle 574g and fat 211g. The best results were obtained with the higher levels of supplementation, 2.50% and 3.75%, as for subjective or objective traits, resulting in carcasses with better appearance, maintaining organoleptic characteristics for long periods, which indicates superior quality carcasses providing a better condition for refrigeration avoiding freezer burn, water loss and meat darkening.