Meat quality of Morada Nova lambs subjected to different feeding regimes

Abstract

This study aimed to evaluate the effect of pre- and post-calving feed restriction on quantitative characteristics and lipid profile of meat from Morada Nova sheep. Twenty-four male lambs from single births only, with an initial weight of 10.0 ± 3.07 kg and at four months of age, were distributed in a randomized complete design, into three groups: pre-calving restriction (R-PRE; n=8) post-calving restriction (R-POS; n=8), and ad libitum feeding (ADLI; n=8). To make up the experimental treatments, the feeding regime applied previously on the sheep in the last third of pregnancy was considered. Treatments ADLI and R-POS were composed of lambs born from ewes fed ad libitum in the last third of pregnancy. Treatment R-PRE consisted of lambs born from ewes subjected to feed restriction in the last third of pregnancy at 60% of the recommended requirements for the group of ewes feeding ad libitum. For the lambs from treatments ADLI and R-PRE, the diet was supplied allowing 20% of the total supplied as refusals. For the animals from R-POS, a 30% restriction was imposed in relation to the animals feeding ad libitum. Animals were slaughtered with an average live weight of 25 kg. Afterwards, carcasses were chilled at 4 ºC for 24 h. Meat quality measurements were taken on the right side of each carcass; pH was determined immediately after slaughter and then again after chilling. Samples of the longissimus dorsi muscle were collected and frozen at -20 ºC. Moisture, ash, protein, total lipids, water-holding capacity, and cooking loss were determined in the meat samples, which were then subjected to the shear-force test. The sensory analysis was determined by the hedonic-scale test, in which sensory parameters of tenderness, juiciness, flavor, aroma, and overall acceptability and fatty acid profile were evaluated. There was a feed-restriction effect on protein, lipids, and water-holding capacity (P0.05). Saturated fatty acid contents were affected by the treatments (P0.05). Feed restriction does not compromise the physicochemical or sensory quality of Morada Nova lambs meat, but rather provides a meat product of good acceptance.