Alexandre Amstalden Moraes Sampaio

Composição química e perfil de ácidos graxos da carne de bovinos de diferentes condições sexuais recebendo silagem de milho e concentrado ou cana-de-açúcar e concentrado contendo grãos de girassol

O objetivo neste trabalho foi avaliar as caracteristicas quimicas e a composicao em acidos graxos do contrafile (musculo Longissimus) de tourinhos, novilhos e novilhas da raca Canchim. Os animais foram terminados em confinamento com duas dietas experimentais, uma com silagem de milho e concentrado e outra com cana-de-acucar e concentrado contendo graos de girassol. Os teores de umidade, proteina e minerais no musculo nao diferiram entre as dietas e as condicoes sexuais dos animais. A carne de novilhos terminados com a dieta com graos de girassol apresentou maior teor de lipidios (3,31%) em comparacao a dos animais de outras categorias. Os animais que receberam a dieta com graos de girassol apresentaram maiores concentracoes de acido linoleico conjugado (18:2 cis9, trans-11) (0,73%) e acidos graxos poliinsaturados (8,12%) no musculo, e tambem relacoes mais elevadas de acidos graxos insaturados:saturados (0,93) e acidos graxos poliinsaturados:saturados (0,16) em comparacao aqueles que receberam a dieta convencional, a base de silagem de milho (0,34%; 6,31%; 0,86; e 0,11, respectivamente). A composicao em acidos graxos da carne de bovinos pode ser melhorada com a utilizacao de cana-de-acucar e graos de girassol na dieta dos animais terminados em confinamento.The objective in this work was to evaluate the chemical characteristics and the fatty acids composition of beef loin (Longissimus muscle) of young bulls, steers and heifers of Canchim breed. The animals were finished in feedlot system and fed two experimental diets, one with corn silage and concentrate (SIL) and the other with sugar cane, as exclusive roughage, and concentrate containing sunflower grains (CNA). Differences were not detected in relation to moisture, protein and mineral contents between diets or sexual categories. The meat from steers that received the CNA diet had higher lipid content (3.31%) in relation to meat from young bulls and heifers receiving the same diet. The meat from animals that received the CNA diet had higher concentrations of conjugated linoleic acid (18:2 cis-9, trans-11) and polyunsaturated fatty acids, and showed higher unsaturated fatty acids:saturated fatty acids and polyunsaturated fatty acids:saturated fatty acids ratios than those of animals fed with SIL diet; respectively 0.73 and 0.34%; 8.12 and 6.31%; 0.93 and 0.86; 0.16 and 0.11. The fatty acids composition in meat from beef cattle can be improved with the utilization of sugar cane and sunflower grains in the finishing diet.

Avaliação econômica e desempenho de machos e fêmeas Canchim em confinamento alimentados com dietas à base de silagem de milho e concentrado ou cana-de-açúcar e concentrado contendo grãos de girassol

The objective of this experiment was to evaluate the effects of diets with corn silage or with sugar cane + sunflower seed and influence of sexual categories of fedlot young cattle on the performance and economic results of this production system. Thirty animals of Canchim breed (10 young bulls, 10 castrated males and 10 females) averagfing 15 months old and 289 kg BW were housed in individual stalls, for 105 days and weighted in the beginning of the experiment and every 35 days. At the end of the feedlot, all the animals were slaughtered in commercial frigorific and measures of carcass characteristics were made. Young bulls showed higher nutrient intakes as compared to females, in absolute values and in relation LW values. The castrated males presented intermediary values, not differing from young bulls and females. Young bulls presented higher daily weight gain and muscular development, represented by the largest rib eye area. They were also more efficient as for feed conversion and carcass yield. No effect was observed for diets on the ingestion of nutrients, except for EE, that was higher for the diet with sugarcane + sunflower seed, with more of this nutrient. Diets also did not influence performance of the animals. Diet with corn silage showed more economically viable to raised young cattle in fed lot finishing. Young bulls were the animals more adequate for the exploration of young cattle in feedlot, independently of diet.

Composição em ácidos graxos e qualidade da carne de tourinhos Nelore e Canchim alimentados com dietas à base de cana-de-açúcar e dois níveis de concentrado

The objective of this work was to evaluate the fatty acids composition and the qualitative and chemical characteristics of the loin meat (Longissimus lumborum muscle) of Nellore and Canchim young bulls. The animals were fedlot finished and fed sugar cane-based diets with two concentrate levels (40 and 60% of dry matter). The concentrates were formulated with sunflower grains, corn, soybean meal, dry sugar cane yeast from sugar and alcohol industry, urea and mineral mixture. The experimental design was a completely randomized design with a 2 × 2 factorial arrangement (genetic group × concentrate level), and the averages were compared by Tukey test at 5% of probability. Differences were not observed in the humidity, protein and ether extract contents of the loin meat. Nellore bulls had higher concentrations of conjugated linoleic acid (0.52%), unsaturated fatty acids (46.82%) and higher unsaturated:saturated (1.02), monounsaturated:saturated (0.86) ratios in their loin muscle when compared to Canchim bulls. Canchim bulls presented higher red and yellow color intensity of meat and higher backfat brightness. A significant genetic group × concentrate level interaction was detected for shear force, where Nellore bulls fed with 40% of concentrate had lower values. The results showed that Nellore bulls had better fat acid composition of the loin meat, concerning human health.

Desempenho e características de carcaça de tourinhos Nelore e Canchim terminados em confinamento recebendo dietas com cana-de-açúcar e dois níveis de concentrado

The objective of this study was to evaluate the performance and carcass traits of young bulls, finished in a feedlot and fed diets with sugarcane (Var. SP 80-1816) and two concentrate levels (40 or 60 % of the DM). Fifteen Nellore bullocks, with approximately 330 kg and 18 months old, and 15 Canchim bullocks (5/8 Charoles ×3/8 Nellore), with approximately 300 kg and 15 months old, were used. The animals were housed in individual pens for a period of 126 days, with the first 21 days of adaptation. The animals were weighed and ultra-sound images were taken at the beginning of the experiment and at every 35 days. A randomized complete design was used in a factorial scheme (2 genetic groups ×2 concentrate levels). There were no significant interactions for any of the evaluated variables. The Canchim animals presented better feed efficiency (0.17 ×0.14) and higher loin eye area gain (19.7 ×13.2 cm2). The 60% concentrate diet improved better daily weight gain (1.44 ×0.98 kg/animal), slaughter weight (499.43 ×460.20 kg), hot carcass weight (265.39 ×244.70 kg) and hindquarter weight (129.74 ×118.68 kg). The Canchim animals presented larger loin eye area (80.89 ×66.85 cm2) and the Nellore animals presented thicker backfat (5.5 ×3.2 mm). Diets with 60% concentrate are better for finishing cattle with high potential for liveweight gain than diets with 40% concentrate.

Estimativa da composição química corporal de tourinhos Santa Gertrudes a partir da composição química e física das 9-10-11ª costelas

Simple linear regressions to estimate empty body chemical composition of Santa Gertrudis young bulls were obtained, using the physical and chemical composition of the 9-10-11th ribs cut. Fifteen intact males, from nine to fifteen months of age and from 220 to 505 kg of liveweight, were kept confined. They were slaughtered after 18 hours without water and food, and six of them were slaughtered after adaptation period. The content of water, protein, lipid and ash were determined on the ribs cut and on the blood, hide, head + feet, visceras and carcass, and samples were obtained after quantitatively grinding and homogenizing the entire tissue. The physical composition of the ribs was determined by manual separation of bone, lean and fat. Empty body weight was closely related to hot carcass weight (r² = 0.99). Percent water and lipid of the 9-10-11th ribs cut were closely related to the empty body chemical composition, but not to the percent protein and ash, that can be calculated from their proportions on the empty body without fat. The physical composition of the ribs cut was a good estimator of the empty body composition, mainly for the equations using separable ribs fat to estimate the contents of water, ether extract and ash, but not protein content. Despite the good results with the ribs cut physical composition, chemical composition was a more efficient estimator of empty body chemical composition, because the coefficients of determination were higher and the standard errors were lower. As the percentage of water in empty body was closely related to the water percent on 9-10-11th ribs (r² = 0.95) and the percentages of ether extract and water in the empty body (r² = 0.94) were closely related each other, the water in the 9-10-11th ribs cut alone can be used to estimate empty body composition.

Avaliação da silagem de grãos de milho úmido com diferentes volumosos para tourinhos em terminação: desempenho e características de carcaça

O experimento foi realizado com o objetivo de comparar os efeitos do fornecimento de silagem de graos de milho umido com o milho em grao seco, associados a silagem de milho ou ao bagaco in natura de cana-de-acucar, sobre o desempenho e as caracteristicas da carcaca de bovinos em terminacao. Em blocos ao acaso e esquema fatorial 2 × 2, 28 tourinhos Santa Gertrudes (dez meses de idade e peso corporal inicial de 245 kg) foram mantidos em confinamento durante 142 dias. Os animais foram mantidos em baias individuais e receberam dietas com 12 e 20% da MS em forma de bagaco ou silagem, respectivamente. O milho umido foi moido e ensilado quando se encontrava com 30% de umidade. Nao houve interacao significativa tipo de volumoso x tipo de processamento do milho sobre as variaveis estudadas. O bagaco mostrou-se viavel como fonte exclusiva de fibra, apesar de os resultados de ganho de peso, eficiencia alimentar, peso e rendimento de carcaca e espessura de gordura subcutânea terem sido inferiores aos obtidos com a silagem de milho. O ganho diario de peso nos animais alimentados com o bagaco foi em torno de 1,3 kg, enquanto, com a silagem, foi de 1,5 kg. O consumo de MS nao foi influenciado pelo tipo de volumoso ou pelo processamento do milho. O uso da silagem de graos de milho umido melhorou a eficiencia alimentar em 9,7% e reduziu o peso do figado quando comparado ao milho seco, mas nao alterou as demais caracteristicas avaliadas.

Composição física da carcaça e aspectos qualitativos da carne de bovinos de diferentes raças alimentados com diferentes níveis de energia

The objective of this trial was to study the physical composition of carcass and the qualitative characteristics of the meat of 16 finishing young bulls, eight Aberdeen Angus (AA) and eight Hereford (HE), fed diets with two energy levels (lower: 3.07 Mcal/kg of digestible energy - 12% of concentrate; or higher: 3.18 Mcal/kg of digestible energy - 32% of concentrate). Animals were feedlot fed since 9 months of age and an average body weight of 220.31 kg and were slaughtered when the estimate carcass weight reached at least 190 kg. A completely randomized design with a 2 x 2 factorial arrangement of treatments (two breeds vs. two energy levels) was used. Within breed, meat from HE showed the lowest loss of liquid during thawing and cooking. Meat from HE animals also showed the greatest tenderness when evaluated either by a panel or by the Shear force technique. Animals fed the higher energy diet had greater proportion of muscle, lower loss of liquid at thawing (2.54 vs. 7.22%), and a more tender meat (Shear force) than those fed the lower energy diet. A significant interaction was observed between breed and energy level for both meat flavor and color; AA bulls fed the higher energy diet had meat with greater flavor and better color.

Aspectos quantitativos de carcaças de bovinos de diferentes raças, alimentados com diferentes níveis de energia

The objective of the experiment was to evaluate the carcass quantitative characteristics of feedlot finished steers, slaughtered at 13-14 months of age. Sixteen calves with nine months of age and average initial weight of 220 kg, being eight Aberdeen Angus - AA and eight Hereford - HE, were used. The animals were submitted to two levels of energy, 3.07 or 3.18 Mcal/kg of DM. The complete randomized experimental design was used, with a 2 x 2 factorial arrangement (two breeds vs. two energy levels). Corn silage with 36% of grain in DM was used as roughage. In the treatments with the lower energy level, the concentrate level was 12% and in the higher energy level, 32% of the diet DM. The animals were slaughtered when the average estimated carcass weight reached 190 kg. The AA animals showed higher hot carcass dressing percentage (54.95 vs. 53.75%), higher leg length (64.12 vs. 62.12 cm) and larger Longissimus muscle area per 100 kg of carcass (29.31 vs. 27.41 cm2). The animals fed higher energy level in the diet showed higher leg length (71.75 vs. 64.50 cm) and better carcass conformation score (11.25 vs. 10.12 points). Significant interaction between breed and energy level was observed for subcutaneous fat thickness, and the higher fat thickness was observed for the carcasses of HE animals, that were fed the lowest energy level.

Desempenho e características da carcaça de tourinhos Santa Gertrudes confinados, recebendo dietas com alto concentrado e níveis crescentes de polpa cítrica peletizada

The experiment was developed to evaluate the effect of the replacement of corn grain by dehydrated citrus pulp pellets on the performance and carcass characteristics of Santa Gertrudis young bulls fed high concentrate diets. Twenty-eight bulls, with average age of nine months and an initial weight of 277 kg, were kept in individual pens and fed during 92 days, after 21 days of adaptation. The animals were fed a diet with 20% of the dry matter as corn silage, with 40% of grain. Treatments evaluated included levels of 0, 25, 40 and 55% of dehydrated citrus pulp pellets in the dry matter diet. There was no effect of citrus pulp level on the average daily gain, daily dry matter intake, feed efficiency, carcass dressing, Longissimus muscle area and the kidney, pelvic and inguinal fat. The increasing level of citrus pulp on the diet decreased linearly the backfat thickness and increased linearly the liver weight and carcass weight. The feces pH was similar for all the citrus pulp levels. Liver abscess were not detected, although the diet had high concentrate level. The dehydrated citrus pulp pellets can compound until 55% of dry matter diet, replacing corn grain to finishing young bulls fed high concentrate diets, with a small decrease in subcutaneous fat.

Digestibilidade e balanço de nitrogênio em ovinos alimentados à base de dietas com elevado teor de concentrado e níveis crescentes de polpa cítrica peletizada

The experiment was developed at Instituto de Zootecnia in Sao Jose do Rio Preto, SP, and the objective was to evaluate the digestibility coefficients, the nutrients intake, and the nitrogen balance of diets with 20% of corn silage and 80% of concentrate and 0, 25, 40 and 55% of citrus pulp in total dry matter, replacing corn grain. Eight crossbred lambs, with nine months of age and 34 kg of liveweight, were fed in individual cages, where feces and urine could be separated. During six days, feed, orts, feces and urine were weighed and sampled. The amount of feed offered was the mean of the intake in the last three days of the adaptation period. The experiment consisted of two phases, using the same animals, which were blocked by liveweight. Data were analyzed by regression. There was linear increase in the apparent digestibility coefficients of the crude protein and of the acid detergent fiber with higher levels of citrus pulp. The digestibility coefficients did not differ and means were, respectively: 71.8, 73.3, 77.2, 63.5, and 72.2%, for dry matter, organic matter, ether extract, neutral detergent fiber and hemicellulose. The total digestible nutrients mean was 72.39%. Increasing citrus pulp in the diet caused a linear and significant increase of dry matter and total digestible nutrients intake by day and by metabolic weight. Similar effects were observed for the amount of ingested, absorbed, urinary and retained nitrogen. An increasing proportion of citrus pulp up to 55% of the dietary dry matter, replacing corn grain, resulted in improvement of the fiber utilization and of the efficiency of nitrogen metabolism.