-The objective was to evaluate the dietary supplementation of different sources of chromium (inorganic: chromium sulfate and chelated: chromium-methionine) during the finishing period of pigs to obtain improvements in the animal performance, and carcass and meat quality. The statistical design was randomized blocks, where 44 barrows, with an initial weight 60.49±5.12 kg, were divided into four blocks (heavier, heavy, light and lighter) according to initial weight. The experimental diets were isoenergetic and isonutrient, except for the chromium level. The treatments were divided as follows: control (without chromium), control + 200 ppb of inorganic chromium (chromium sulfate), and control + 200 ppb of chelated chromium (chromium-methionine). In the performance measures, the stall was considered the experimental unit and in the blood parameters, carcass and meat evaluations each animal constituted the experimental unit. Animals were slaughtered when they reached the final average weight of 107.23±5.23 kg. Blood samples were collected and tested for blood parameters (cholesterol, triglycerides and glucose) as well as carcass quality (hot and cold weights, yield, loin-eye area, muscle depth and backfat thickness) and meat quality (initial and final pH, drip loss, color, chemical composition and lipid oxidation) parameters. Chromium-methionine supplementation provides a greater daily weight gain only compared with the animals that are not supplemented with chromium, because feed conversion is better as compared with the other treatments. After 24 hours of storage, the meat from pigs supplemented either with chromium-methionine or with chromium sulfate presents lower lipid oxidation than that from non-supplemented animals. However, after three days of storage, only chromim-methionine is effective in reducing lipid oxidation.

ResumoObjetivou-se com o estudo avaliar os efeitos da imunocastração sobre o ganho de peso, características de carcaça e qualidade da carne de novilhos Nelore. Foram utilizados oitenta bovinos Nelores, com peso inicial médio de 357±8,63 kg, que foram alimentados em confinamento e distribuídos em dois tratamentos com 40 bovinos inteiros e 40 imunocastrados (Bopriva ® , Pfizer Saúde Animal). Os imunocastrados receberam duas doses da vacina, sendo a primeira aplicação 30 dias antes da entrada dos animais em confinamento e a segunda na entrada do confinamento. Ao final do período experimental de 67 dias, calculou-se o ganho diário de peso vivo em kg/dia dos 80 animais e selecionou-se 20 de cada grupo para o abate e avaliações de carcaça, e posteriormente dez de cada tratamento para as análises de carne. Os dados foram submetidos à análise de variância. Animais imunocastrados apresentaram menor ganho diário de peso vivo, peso de carcaça quente, rendimento de carcaça, pH final, espessura de perna, profundidade de músculo, área de olho de lombo, porcentagem de músculo, força de cisalhamento e umidade. Entretanto, obtiveram maior concentração sanguínea de lactato e cortisol, profundidade torácica, espessura de gordura subcutânea, grau de cobertura da carcaça, a*, b* e c*, perda de líquido no descongelamento, índice de fragmentação miofibrilar e extrato etéreo da carne em relação aos inteiros. A imunocastração (Bopriva ® ) é uma alternativa para melhorar a qualidade da carne, através da maior deposição de gordura na carcaça e redução da força de cisalhamento da carne em relação aos animais inteiros. Palavras-chave: Grau de acabamento, hormônio liberador de gonadotrofinas, imunização, maciez, novilhos AbstractThe objective of this study was evaluate the effects of immunocastration on body weight gain, carcass characteristics and meat quality of Nellore beef cattle. Eighty Nellore beef cattle, with initial body weight of 357±8.63 kg, were placed in feedlots and distributed in two treatments (40 animals per treatments) as follow: one -non-vaccinated bulls and two -immunocastrated bulls (Bopriva ® , Pfizer Animal Health). The animals placed on treatment two were vaccinated in two doses, first application 30 days before they arrive on the feedlots and second on the day they arrive on feedlots. After 67 days

Traditional marbling meat evaluation is a tedious, repetitive, costly and time-consuming task performed by panellists. Alternatively, we have Computer Vision Systems (CVS) to mitigate these problems. However, most of CVS are restricted to specific environments, configurations or muscle types, and marbling scores are settled for a particular marbling meat standard. In this context, we developed a CVS for meat marbling grading, which is flexible to different muscle colour contrasts and grading standards. Essentially, the proposed method segments an image pre-processed by illumination normalisation and contrast enhancement, analyses visible intramuscular fat pixels and attributes a score based on a desired meat standard defined in the learning step. Learning approach is an instance-based system making use of k-Nearest Neighbours algorithm (k-NN) to attribute a score from segmentation results. The algorithm classifies the new samples based on scores assigned by panellists. We investigated the optimal number of samples for modelling, focusing on the smallest number leading to acceptable accuracy, and considering two different animal species: bovine and 1 swine. The CVS led to accuracy values equal to 81.59% (bovine) and to 76.14% (swine), using only three samples for each marbling score.

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 Student's t-test and Pearson's 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.

There was evaluated the performance, carcass characteristics and meat quality parameters of swine on the finishing stage receiving a dietetic supplementation with magnesium oxide (MgO). The animals were 48 male swine, supplemented 7 days before the slaughter by the following treatments: feed with 0; 0.2; 0.4 e 0.6% of MgO inclusion. The pigs were blocked by the initial weight as: lights, medium and heavy. The treatments had influence on the daily weight gain showing a quadratic effect, maximum inclusion point 0.3% MgO. The effect on the plasmatic cortisol and on the carcass yield was a linear decreasing regression. Back fat thickness shows a quadratic effect, minimal deposition point 0.37% MgO. Amount of meat in chilled carcass, meat yield and gratification index showed quadratic effect for the treatments, the maximum points are 0.31, 0.37 and 0.28% of inclusion respectively. Water losses and liquid losses on defrosting presented quadratic effect; the minimal point was to 0.31 and 0.35% of inclusion, respectively. Key words: Back fat thickness, carcass yield, meat color, stress ResumoO objetivo deste experimento foi avaliar o efeito da inclusão de óxido de magnésio (MgO) na fase de terminação sobre o desempenho, as características de carcaça e qualidade de carne de suínos. Foram utilizados 48 suínos, suplementados com MgO por 7 dias antes do abate, sendo os tratamentos: rações com 0; 0,2; 0,4 e 0,6% de inclusão de MgO. O delineamento experimental foi em blocos casualizados, sendo os animais blocados de acordo com o peso inicial em leves, médios e pesados. O ganho diário em peso foi influenciado pelos tratamentos, apresentando efeito quadrático com ponto de máxima inclusão de 0,3% de MgO. A suplementação com MgO diminuiu as concentrações séricas de cortisol, apresentando efeito de regressão linear decrescente. A espessura de toucinho apresentou efeito de regressão quadrática, em que o ponto de mínima deposição ocorreu com a inclusão de 0,37% de MgO. Quantidade de carne na carcaça resfriada, rendimento de carne na carcaça e índice de bonificação apresentaram efeito quadrático para suplementação dietética com MgO sendo os pontos de máxima 0,31, 0,37 e 0,28% respectivamente. A porcentagem de perda de água e a perda de água no descongelamento apresentaram efeito quadrático, com pontos de mínima perda iguais a 0,31 e 0,35%, respectivamente.