Marina Avena Tarsitano

Fatty acid profile of beef from immunocastrated (BOPRIVA(®)) Nellore bulls.

Twenty Nellore bulls (ABW=357.7±9.65kg) were divided into 2 groups: intact and immunocastrated - Bopriva®. After the trial period, the cattle were slaughtered and carcass fat thickness was evaluated, ether extract and fatty acid composition of the longissimus thoracis analyses were performed, and the activity indices of relevant enzymes were calculated. The means were calculated and compared by Students t-test and Pearsons correlation coefficients (p<0.05). The immunocastrated group showed higher back fat thickness, ether extract, monounsaturated fatty acids (MUFAs), and activity index of Δ(9) desaturase C18 and lower polyunsaturated fatty acids (PUFAs) and n-6 fatty acids when compared to the intact group. The correlations between ether extract and the saturated and monounsaturated fatty acids were positive, and negative with polyunsaturated, n-3, n-6 and PUFA/SFA. Therefore, immunocastration may improve the fatty acid profile in the longissimus thoracis by increasing MUFAs, mainly oleic acid that is the most representative fatty acid in the meat and is considered beneficial to health.

Effect of low or high stress in pre-slaughter handling on pig carcass and meat quality

The objective of this study was to evaluate the consequences of low or high stress during pre-slaughter handling of pigs on their carcass and meat quality. Forty-four animals of a commercial lineage, with an average weight of 107.23±5.23 kg, were used. At lairage the animals were randomly divided into two groups, the least and the most stressed. At slaughter, during bleeding, blood samples were collected for later cortisol and lactate tests. Forty-five minutes after slaughter the initial pH of th carcasses was measured and samples of the semitendinosus muscle were collected for R-value calculation. After 24 hours of cooling, the final pH was measured, damage scores were assessed and samples of the longissimus dorsi muscle were collected to evaluate drip loss, liquid loss from defrosting and cooking, shear force, lipid oxidation, and color. The results were evaluated by analysis of variance and the means were compared by Tukey´s test. It was found that cortisol, lactate and R-value were lower and initial pH was higher for the least stressed animals, whereas the other parameters were not significantly affected. Thus, low stress in the pre-slaughter handling of pigs is effective in reducing stress and carcass damage, but has no effect on meat quality.

Efeito de dietas contendo plasma sanguíneo desidratado sobre características microbiológicas, imunológicas e histológicas de leitões leves ao desmame

The aim of this experiment was to evaluate the effects of spray-dried plasma (SDP) on the growth performance, immunological, histological and microbiological profile and weight of organs of light weight weaned pigs. The trial was done using 24 pigs with an initial mean age of 21 days in a completely randomized experimental design. The treatments were: T1 - heavy weight weaned pigs, without SDP supplementation; T2 - light weight weaned pigs, supplemented with 10g/animal/day of SDP; T3 - light weight weaned pigs, supplemented with 20g/animal/day of SDP; T4 - light weight weaned pigs, without SDP supplementation. The inclusion of 20g of SDP in the diet improved the weight gain, spleen weight (g/kg) and serum IgA title between 21 and 31 days of age. The inclusion of 10g of SDP in the diet improved the length and width of the ileocolic lymph node. In the first 10 days after weaning, SDP improved the development of lymphoid organs and the protection of the intestinal mucosa.

Performance, carcass and meat quality of ewes supplemented with magnesium oxide

The objective of this study was to evaluate the performance, the carcass and meat characteristics of ewes supplemented with magnesium oxide. Eighteen 6-year-old Santa Ines ewes were used in a completely randomized experimental design, where three levels of supplementation (0.0, 0.1 and 0.2% magnesium oxide in the concentrate) were tested, with six replicates. Final weight, weight gain, feed intake and feed conversion were not affected by levels of magnesium supplementation. Hot and cold carcass weights showed linear increasing and quadratic responses, respectively, according to supplementation with magnesium. Carcass measurements such as length, depth, and measures of arm and leg were not affected by supplementation. Depth and width of the longissimus muscle and rib-eye area were not affected; however, marbling and ether extract increased linearly with supplementation. Water loss and color were not affected. Lipid oxidation and shear force were not affected by supplementation, while the myofibrillar fragmentation index showed a quadratic regression. There was a linear decrease in pH with magnesium supplementation. Supplementation with magnesium can improve carcass and meat pH, but can act negatively by increasing the amount of marbling and ether extract of meat.