A Rapid Technique for Determination of Total Disappearance of Dietary Nitrogen in the Digestive Tract Using Washed Fecal Sample after Freezing and Thawing

Kedah-Kelantan cattle were immunised against somatostatin (SS) and the animals slaughtered on the 45th week. Viable fat expiants were cultured in vitro in the presence of insulin (10 -10 M), cholecystokinin (CCK), gastric inhibitory polypeptide (GIF), glucagon-like polypeptide (7-35) (GLP-1) or SS (each at 10 -9 M) and the rate of lipogenesis determined. Immunisation had no effect (P>0.05) on growth performance, feed conversion .ratio or carcass weight (P>0.05). SS-immunised cattle had lower (P 0.05). CCK and GLP-1 stimulated (P 0.05) both subcutaneous back fat and subcutaneous tail fat lipogenesis. These effects were diminished for SS-immunised animals. GLP-1 did not affect subcutaneous back fat and perirenal fat in either treatment group. The effects of immunisation against SS on carcass composition may be mediated by changes in fat tissue responsiveness to hormones from the digestive tract.