Effects of Autoclaving and Steaming of Cottonseed Meal for Different Lengths of time on Nitrogen Solubility and Retention in Sheep

Sheep digestibility and nitrogen retention trials were used for determining optimum autoclaving time of cold-hexane extracted cottonseed meal for maximum nitrogen retention. Portions of the meal were autoclaved under LOS kg./cm.2 pressure for 30, 45, 60,75 or 90 min. It was found that between 45 and 75 min. of autoclaving time was required to produce a meal in which maximum nitrogen retention occurred. In trial 2 portions of dehulled cotton seed were subjected to live steam at atmospheric pressure (94° C.) for 0, 10, 20, 40, 60, 80 or 100 min., and then the oil was extracted with cold hexane. Nitrogen solubility decreased only slightly, but in a linear fashion, as heating time was increased. Using sheep it was found that the unheated meal had the highest protein digestibility and urinary nitrogen excretion, and the effect of heating on these criteria was expressed by a quadratic equation.