Effect of straw particle size in high grain complete pelleted diet on growth performance, rumen pH, feeding behavior, nutrient digestibility, blood and carcass indices of fattening male goats

The study aimed to elucidate the effects of straw particle size of complete pelleted diet (CPD) on feed intake, growth performance, rumen pH, feeding behavior, selected blood metabolites, nutrient digestibility, and carcass attributes of fattening male goats. Sixteen male Beetal goats, averaging 27.0 ± 2.84 kg body weight (BW) were randomly assigned to one of the following dietary treatments (n = 8 male goats /treatment); 1) S4 (CPD having oat straw ground at 4 mm); 2) S8 (CPD having oat straw ground at 8 mm). The diets were iso-nitrogenous and iso-caloric with forage to concentrate ratio of 15:85, and were designed to achieve low NDF contents of 20% by adding 63% corn grains. The experiment lasted for 16 weeks; 2 weeks of receiving and diet adaptability period, 13 weeks of data collection, and last one week for nutrient digestibility. Animals were housed individually and fed the corresponding diet and water ad libitum. Feeding behavior was recorded on day 30, 60, and 90 of the study. Blood samples were collected weekly, whereas, rumen samples were collected on a bi-weekly basis. Total tract nutrient digestibility was performed at the end of the experiment. All goats were slaughtered to determine changes in the carcass attributes. Results revealed that DMI and ADG were higher (P