DIETAS DE ALTA PROPORÇÃO DE CONCENTRADO PARA BOVINOS DE CORTE CONFINADOS

• Autor(a) principal: SILVA, Hélio Lourêdo da
• Data de Publicação: 2009
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tde/1173
• topic: consumo, crescimento, fezes, ingestão; feces, growth, ingestion, intake; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::PRODUCAO ANIMAL

The objective of this study was to evaluate the effects of high grain diets on performance, carcass characteristics, feeding behavior and fecal parameters of 20 Nelore bovines with 28 months of age. The diets DT + BIN (10% sugar cane bagasse, 54.52% cracked sorghum, 10.94% whole cotton seed hulls, 18% soybean hulls, 2.54% soybean meal and 4% powder vitamin/mineral supplement), MGI (10% soybean hulls, 75% whole corn grain and 15% pellet vitamin/mineral supplement) and DT (44.44% cracked sorghum, 16.7% whole cotton seed hulls, 28.89% soybean hulls and 10% powder vitamin/mineral supplement) were offered to the animals in tie stalls in a completely randomized experimental design. Intake was determined through subtraction of the feed minus orts. Diets were offered to the animals in two daily meals, at 8h (60%) and 17h (40%), aiming approximately 5% of orts. Animals were weighed in the beginning of the experiment and every 21 days, always in water fasting and 14 hours after the last meal. The pH and the lengths of the half-carcasses were measured in the cool store after the cooling process had been completely finished. The areas of AOL and EGSO were taken from the left half-carcass in the 12th rib. Registrations of time spent with feeding, rumination, rest and water intake were done by visual observations of the animals every five minutes during 24 hours. For determination of feces pH and fecal starch, samples of feces were taken from the rectum of each bovine. There was difference for final weight and metabolic weight (P<0.05). Animals fed the diet DT + BIN (498.43 kg final weight and 93.27 kg metabolic weight) and the diet MGI (481.67 kg final weight and 90.32 kg metabolic weight) were more efficient than the ones fed the diet DT (456.43 kg final weight and 88.52 kg metabolic weight). Dry matter intake was greatest for the animals fed the diet DT+BIN (9.24 kg/day) and MGI (7.34 kg/day) than animals fed the diet DT (6.92 kg/day). When intake was expressed as percentage of bodyweight, the treatment DT + BIN was 20.99% higher than MGI and 26.59% than DT. There was difference (P<0.05) in the weight of fresh carcass (PCQ) and thickness of subcutaneous fat (EGSS). PCQ in the treatment DT + BIN (281.81 kg) was higher than DT (238.2 kg), but did not differ from MGI (268.98 kg). Likewise, EGSS in the diet DT+BIN was 12.36% higher than the diet MGI and 50% higher than the diet DT. There was difference for time spent with mastication, rumination, rest and water intake among diets (P<0.05), except for the time spent with feeding. Times spent for rumination and mastication were higher in the treatment DT + BIN (181.2 and 278.4 min/day), however there was no difference (P>0.05) between the diets MGI (94.2 and 171 min/day) and DT (60 and 148.2 min/day). Times spent for rest and water intake differed among treatments, with means of 436.8 and 4.46 min/day in the diet DT+BIN, 546 and 2.81 min/day in the diet MGI and 568.8 and 4.02 in the diet DT. Means of percentage of fecal starch, fecal dry matter, pH in the site of starch fermentation and starch intake were not influenced by diets (P>0.05). Score of fecal consistency and feces NDF were affected (P<0.05) by treatments, with means of 3.12 and 46.29% in the diet DT+BIN, 2.92 and 35.65% in the diet MGI and 3.2 and 48.97% in the diet DT. The addition of 10% of BIN in high grain diet improves dry matter intake, weight gain and carcass quality. The MGI diet was greater than the DT diet in terms of daily weight gain at 84 days and fresh carcass weight. Times spent for rumination, mastication and feed efficiency (g NDF/h) and (g peNDF/h) were greatest in the diet DT+BIN. The fecal consistency evaluated in the animals belonged to the diet DT+BIN, scored as firm, suggests that these animals presented better ruminal fermentation