Suchergebnisse

The objective of this study was to determine the effect of pre-slaughter time about some blood constituents used as stress indicators in the evaluation of animal welfare in cattle. In the practice of ethology, animal welfare is assessed through physiological and behavioral indicators. For the determination of serum biomarkers of animal stress, a total of 180 animals was used, divided into two major groups according to the time of pre-slaughter. In the acceptable group, the animals had a pre-slaughter time up to 24 hours and in the not acceptable group the pre-slaughter time was greater than 24 h. These two groups were split up into three animal categories (males, females and castrated males). In this study, 30 samples were collected from each animal category of the two groups, acceptable and not acceptable, totaling 180 samples. Samples were separated for analysis of muscle enzymes creatine kinase and lactate dehydrogenase (CK and LDH), glucose and cortisol. Physiological values, regardless of the animal category and pre-slaughter time, were higher than the normal values of reference, expressing the prior management effect on animal welfare. The data clearly show a need to update and adapt the entire production chain to animal welfare practices, with the objective of producing competitive quality meat in the world market.

Strategies to improve beef nutritional value, mainly fatty acid composition, have been a major goal for the scientific community. The use of different oil contents, mostly those rich in unsaturated fatty acids, can be interesting for cost reduction, as well as cattle performance and meat quality improvements. This study assessed the influence of diets containing increasing linseed oil levels (1.0, 3.8, and 5.2% DM) on performance, carcass traits, and meat quality of feedlot-finished Nellore x Canchim steers and heifers. The experiment was carried out in a randomized block design and arranged in a mixed 3 x 2 factorial scheme. Increasing oil levels linearly decreased dry matter intake (DMI) (P < 0.05) and hence improved feed efficiency (P < 0.05), regardless of sexual condition. A beneficial effect of increasing the inclusion of linseed oil was the reduction DMI. Steers had a higher weight at slaughter (P < 0.05) and heifers had greater backfat thickness (P < 0.05). The concentrations of most fatty acids were changed by the linseed oil levels studied (P < 0.05). Dietary inclusion of linseed oil improved beef quality by reducing (P < 0.05) the n-6:n-3 ratio by 1.3 points per percentage point increase in linseed oil level in the finishing diet of both sexes.