Suplementos múltiplos para bovinos de corte nas fases de cria, recria e terminação em pastagens de Brachiaria decumbens

• Autor(a) principal: Porto, Marlos Oliveira
• Data de Publicação: 2009
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1716
• topic: Bovino de corte; Suplementação; Pasto; Beef cattle; Supplementation; Forage; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::NUTRICAO E ALIMENTACAO ANIMAL

The current thesis was realized with base on five trials. At the first trial, the performance, intake and digestibility in Nellore beef calves, supplemented with different energy sources in pasture of Brachiaria decumbens and sex effect were evaluated. The area was divided in five paddocks of 6.8 ha, with an availability of dry matter and potentially digestible dry matter of 4.10 and 2.38 t/ha, respectively. Fourty-five animals with 96.0 ±11.0 kg of begin initial weight and 101 ±12 days of age, in completely randomized experimental design, in factorial 4x2+1 (four energy sources, two sex and mineral mix). The following supplements were evaluated: 1 mineral mix (MM), control group; 2 soybean meal (SM) + ground corn grain (GCG) and MM; 3 SM + wheat meal + GCG and MM; 4 SM + rice meal and MM; 5 SM + ground sorghum grain + GCG and MM; supplied daily on the amount of 60 g/animal, control group and 500 g the others treatments, respectively. Occurred statistical significance (P<0.10), the animals that received supplement with ground corn grain and ground sorghum grain showed a additional average daily gain of 100 g (16.39%) higher than the animals that received only mineral mix. The use of multiple supplements based on ground sorghum grain and corn grain provided increase (P<0.10) in intake of dry matter and organic matter of forage than the treatment with ground corn grain. In conclusion, the supplementation with energy sources with ground sorghum grain and corn grain can provides additional average daily gain and increase in intake of forage, during the phase of calf growth. At the second trial, the performance, and nutritional characteristic in crossbreds bulls Nellore/Holstein, in growing, receive different supplements offers in pasture of Brachiaria decumbens were evaluated. The area was divided in five paddocks of 2.0 ha, with an availability of dry matter and potentially digestible dry matter of 3.88 and 2.22 t/ha, respectively. Thirty animals with 230.0 ±6.14 kg of begin initial weight and 8.5 months of age, in completely randomized experimental design, with five treatments, and four supplementation levels. Were evaluated the mineral mix (60 g/day) and multiples supplements, formulated to supply different supplementation levels in the amounts of 0.5, 1.0, 1.5 and 2.0 kg/day and supply 300 g/day of crude protein. The animals answered to the use of multiples supplements, gain more weight (88.72%), as well as the levels of seric N- urea were great (P<0.10) (19.95 vs. 9.66) when compared with animals supply with mineral mix. The animals supplemented shows higher (P<0.10) intake of DM, OM, EE, NDF, NFC and TDN in relation to animals no supplemented, and this intake increase (P<0.10) with the energy levels provided to bulls. The supplementation increases the coefficient of digestion to the greater number of variables, independent of energy level supply. It follows that levels more low (0.5 kg of supplement) of supplements may be supply to bulls in growing, during the dry season, to stimuli intake of pasture, whereas the yield microbial maxima is obtained with 1.34 kg offered supplement, the responses best of performance and nutritional characteristics appear were this intervals of supply of supplementation. At the third trial, the performance, and nutritional characteristic in crossbreds bulls Nellore/Holstein in growing, supplemented with association of energy and protein sources in pasture of Brachiaria decumbens were evaluated. The area was divided in five paddocks of 2.0 ha, with an availability of dry matter and potentially digestible dry matter of 3.13 and 1.98 t/ha, respectively. Thirty animals with 268.0 ±6.70 kg of begin initial weight and 11.5 ±0.18 months of age, in completely randomized experimental design, in factorial 2x2+1 (two energy sources, ground corn grain and wheat meal; and protein sources, urea and soybean meal and; mineral mix), with four supplements, more a control group received only mineral mix resulting five treatments, with six replicates. The mineral mix was supply daily in amount of 60 g/animal, and the others multiples supplements, 1.0 kg/animal, supply 300g/day of crude protein. The animals received multiples supplements increase the weight gain (46.81%), to result the levels in serum of N-urea great (P<0.10) to the animals that received urea or wheat meal in supplements. The animals supply showed increase (P<0.10) intake of DM, OM and TDN in relation no supplements animals, the intake of DM of pasture was not significative (P>0.10) by different association energy- protein, as well as by use this in relation for the control group. The coefficient of digestion of NDF was great with use of wheat meal how energy source. To recommend the use of ground of corn grain or the of wheat meal, how energy source, associated in soybean meal or the mix urea/sulphate of ammonia in formulation of multiples supplements to increase the performance of steers in growing, during the drywet season transition. At the fourth trail, the performance, and nutritional and carcass traits in crossbreds bulls Nellore/ Holstein, supplemented with different supplementation levels in pasture of Brachiaria decumbens were evaluated. The area was divided in five paddocks of 2.0 ha, with an availability of dry matter and potentially digestible dry matter of 4.53 and 3.15 t/ha, respectively. Twenty-three animals with 326.5 ±11.04 kg of initial weight and 14.65 ±0.25 months of age, the three animals reference group was slighted at the beginning for valuation the carcass gain, the others bulls assigned in completely randomized experimental design, with four treatments, and three supplementation levels. Were evaluated the mineral mix (60 g/day) and multiples supplements, formulated to supply different supplementation levels in the amounts of 0.75, 1.5, and 2.25 kg/day and supply 400 g/day of crude protein. The animals response to the use of multiples supplements, gain more weight (P<0.10) (33.14%), to average gain of empty body, yield of carcass hot and cold the response in the supplementation levels were increasing linearly, as well as the levels of seric N-urea were great (P<0.10) (16.0 vs. 9.50 mg/dL) when compared with animals supply with mineral mix. The animals supplemented shows higher (P<0.10) intake DM, OM, PB, EE, NDF, NFC and TDN in relation to animals of control group, whereas decreasing linearly (P<0.10) the digestibility of the NDF with the increase supplementation levels. It follows, utilization of multiples supplements in amount of 0.75 kg (2.0 g/kg of body weight) is an alternative to increase the average daily gain, in great amounts, adding only energy and maintaining the amount of supply protein, decrease the digestibility the of NDF, whereas no decrease the performance animal. At the fifth trail, the objective was to estimate the energy, protein and macrominerals requirements of supplemented crossbreds bulls Nellore/ Holstein grazing Brachiaria decumbens Stapf. pasture during the rainy season. Thirty five intact males, with eight months old and initial body weight of 230.6 ± 6.13 kg were used. Ten animals were slaughtered as reference, in different weight range. The net energy requirements for weight gain were obtained by regressing the log of the retained energy (RE) on the log of empty body weight gain (EBWG). The net Ca, P, Mg, Na and K requirements were determined by the equation Y = a .b. Xb-1, where a and b represent the intercept and the regression coefficient, respectively, of the prediction equations of Ca, P, Mg, Na or K contents in the empty body weight. The net energy requirements for maintenance (MEm) were obtained from regression of the RE on the metabolizable energy intake. The requirements of MEm of cross-over bulls, under pasture, was 125 kcal/EBW0.75/day. The efficiency of ME utilization for maintenance (km) of crossbreds bulls Nellore/Holstein under pasture was 58% and for gain (kg) 24%. The total metabolizable protein requirements for an animal of 400 kg and an average daily gain of 1.0 kg, were 638.36 g/day. The dietetic requirements of Ca and P to animals of 400 kg, respectively, 0.49 and 0.21 (% of DM). The daily requirements of maintenance metabolizable energy to Nellore/Holstein cross-over bulls were of 125 Kcal/kg EBW 0,75 was 15% up on those observed to feedlots in Brazil (108 Kcal/kg EBW0,75).