The effect of weight stasis on the non-carcass components of crossbred sheep

Abstract

A study was made of the non-carcass components of 16 crossbred wethers (progeny of Dorset Horn rams and Border Leicester x Merino ewes) maintained at 30 kg liveweight for either 0,25, 50 or 75 days. Animals were individually penned and fed a pelleted ration of 80% lucerne chaff and 20% cereal grain (89.3% dry matter, 14.8% crude protein and 18.27 kJ/g gross energy). The weight of hooves increased significantly (P < 0.05) during weight stasis, while the weight of the liver decreased significantly (P < 0.001) as did the weight of the kidneys (P < 0.01). Neither head, skin, heart, lungs, spleen, pancreas nor total alimentary tract fat weight was influenced by weight stasis. The separate parts of the alimentary tract did not respond to the weight stasis treatment in the same manner. The weight of the rumen-reticulum, small intestine and large intestine each showed a significant reduction (P < 0.001) in weight. In contrast, neither omasum nor abomasum weight was affected by weight stasis. Total alimentary tract weight was significantly reduced (P < 0.001) by weight stasis. An evaluation of the weights of digesta in the separate parts of the alimentary tract showed that the weight of omasal contents increased significantly (P < 0.01) during weight stasis, while small intestine contents weight decreased significantly (P < 0.01). The weight of contents in either the rumen-reticulum, abomasum, large intestine or total alimentary tract was not influenced by weight stasis.