Determining the optimal level of buffel grass hay as a source of physically effective fiber in a diet with high proportions of forage cactus for sheep finished in the feedlot.

The objective was to determine the optimum level of buffel grass hay (Cenchrus ciliaris L.) as a source of physically effective fiber in diets with high proportions of forage cactus on the bioeconomic performance of sheep finished in a dryland feedlot. A completely randomized experimental design was employed, consisting of four treatments and ten replications, with treatments defined by the levels of buffel grass hay (45, 30, 15, and 7.5% of buffel grass hay in the diet’s dry matter). A quadratic effect was noted for intakes of organic matter, dry matter, crude protein, ether extract, neutral detergent fiber, non-fibrous carbohydrates, total carbohydrates, total digestible nutrients, and metabolizable energy, with maximum intakes estimated at 35, 42, 23, 20, 25, 10, 25, and 24% of buffel grass hay, respectively. A linear effect was observed for all apparent digestibility variables. A quadratic effect was identified for final weight, total gain, and average daily gain, with maximum gains estimated by the regression model at levels of 27, 27, and 28% buffel grass hay, respectively. Based on productive performance and net income achieved in feedlot, the inclusion of 30% buffel grass hay in diets with high proportions of forage cactus is recommended for sheep in the feedlot.