Rumination In Sheep Research Articles

Rumination in sheep. III. Experimentally induced variations on the circadian pattern of rumination

The circadian (24-hr) pattern of rumination of caged sheep was found to be affected: (a) by the administration of a roughage ration per fistulam; (b) by the emptying of the rumen and the subsequent return of the rumen contents; (c) by the emptying of the rumen and the replacement of the contents by a buffer solution plus roughage. The period during which no rumination occurred following feeding was progressively shortened when increasing proportions of a ration of oaten chaff and lucerne chaff were administered per fistulam. The effect was much reduced when high protein sheep cubes were added to the chaff ration. The removal of the rumen contents after voluntary feeding and then their immediate return to the rumen tended to cause an early commencement of rumination. When the rumen contents were "pasteurized" before return, however, rumination did not occur for an extended period afterwards. When the rumen contents were replaced with buffer solutions plus roughage, variable rumination responses occurred. In one instance apparently uninhibited rumination resulted.

Rumination in sheep. I. The influence of rumination and grinding upon the passage and digestion of food

The nutritional significance of rumination was investigated in relation to certain aspects of rumen function, by using:(a) a chaffed roughage ration on which rumination was either allowed to occur normally or was restricted by means of a muzzle, and (b) a finely ground ration with either the normal rumination or with the addition of polyethylene flakes to stimulate rumination. An apparatus for recording jaw movements was used to measure the extent of rumination. Compared with the chaffed ration, grinding resulted in a shorter retention time of stained particles in the digestive tract, and lower apparent dry matter, organic matter, and crude fibre digestibilities. The addition of polyethylene flakes to the ground ration tended to further decrease retention time and caused a lowering of apparent dry matter, organic matter, and crude fibre digestibilities. The effect of muzzling, to restrict rumination, was to markedly increase the retention time, and this was accompanied by higher apparent dry matter, organic matter, and crude fibre digestibilities than when rumination was not restricted. Supplementary rumen metabolic data are presented. The importance of the mechanical activity in the digestive process is stressed.

Rumination in sheep caused by injection of adrenaline.

THE injection of adrenaline into sheep anaesthetized with chloralose causes a rapid secretion of parotid saliva1. This is a reflex effect and appears to be due largely to stimulation of receptors in the forestomach. Parotid secretion is also increased by mechanical stimulation of the forestomach and in conscious sheep this stimulation may cause rumination2. Thus it seemed of interest to find whether adrenaline would cause the conscious sheep to ruminate, and observations on this subject are summarized here.