No abstract

-Three different genetic groups were evaluated for growth up to slaughter and carcass quality for kill out, commercial cuts, non-carcass components, as well as carcass morphometric measurements. Pure Santa Ines (SI), ½ Ile de France × ½ Santa Ines (I × SI) and ½ Texel × ½ Santa Ines (T × SI) lambs were weighed weekly until they reached predetermined slaughter weight (30, 35, 40 and 45 kg). In both creep feeding and fattening the animals from crosses were superior to the Santa Ines hair sheep in terms of daily weight gain and weaned in less time. Crossbred animals also showed better performance than purebred Santa Ines in terms of commercial cuts and carcass weights. Correlations showed that fat depth and eye muscle area decreased with an increase in morphometric measures, indicating that larger animals are possibly later developing in terms of carcass finishing compared with smaller animals. The optimal slaughter weight is approximately 35 kg.

Com este estudo objetivou-se avaliar a viabilidade econômica da produção de cordeiros cruzados em confinamento, bem como determinar qual o peso de abate mais rentável. Foram utilizados 53 ovinos, machos e fêmeas, oriundos de três grupos genéticos diferentes: Santa Inês (SI), Ile de France x Santa Inês (ISI) e Texel x Santa Inês (TSI). Agruparam-se os animais em diferentes pesos vivos (PV) para o abate (30, 35, 40 e 45 Kg). Foram analisados os custos variáveis.

The object of this experiment was to study physicochemical and sensorial traits in the 11th and 13th ribs of 24 Santa Ines (SI), 24 1/2 Ile de France × 1/2 Santa Inês (ILE × SI) and 8 1/2 Texel × 1/2 Santa Inês (TE × SI), slaughtered at different weights (30, 35, 40 and 45 kg, respectively). Subjective measurements (marbling, colour and texture) were carried out on the Longissimus dorsi, as well as initial pH (0 h) and final pH (24 h) after slaughter. The experiment was in a 3 × 4 factorial design and analysed using general linear model and correlation procedures in SAS®. Breed group did not influence colour (3.32), shear force (3.57 kg-force (kgf)) or loss in cooking (24.05%) of the L. dorsi, but slaughter weight affected these, with stronger colour, tougher meat and greater loss in cooking as slaughter weight increased. For sensorial analysis, the L. dorsi were cut, identified and evaluated by 30 untrained judges using a linear scale. Significant differences were detected in preference (6.61 points), tenderness (6.32 points), succulence (6.33 points) and flavour (7.08 points) of the meat from different breed groups and slaughter weights. For preference, all meats were well accepted although the crossbred animals slaughtered at 45 kg were less acceptable.

This study aims to investigate the effect of breed and slaughter weight on fatty the acid profile of the Longissimus dorsi muscle in lambs. Twenty-four Santa Inês (SI), 24.5 Ile de France × 0.5 Santa Inês (Ile × SI) and 12.5 Texel × 0.5 Santa Inês (Te × SI), slaughtered at different weights (30, 35, 40, and 45 kg), were evaluated. The animals were reared with creep feeding to weaning and were feedlot finished, receiving a diet composed of 30% hay and 70% concentrate. The analyses of fatty acids were carried out on the Longissimus muscle of the 13th rib. The experiment was in a three by four factorial design. The total mean saturated fatty acid level was 44.88%, with 43.30% monounsaturated fats and 1.72% polyunsaturated. The major fatty acids found included oleic (43%), palmitic (22%), and stearic (18%). The concentration of desirable fatty acids varied from 61.56% to 66.78%, with Te × SI (66.78%) having the highest levels (P < 0.05). The slaughter weight affected (P < 0.05) the saturated and unsaturated (both mono and poly) fatty acid profiles. The 35-kg slaughter weight showed the most desirable fatty acid profile. The saturated myristic and stearic fatty acids decreased with an increase in the slaughter weight, but oleic acid increased. In the conditions of the present study, the meat from Santa Ines and Texel × Santa Ines lambs had fatty acid profiles more beneficial for human health due to the higher levels of unsaturated fatty acids.