The effect on protein utilization of feeding different protein supplements via the rumen or via the abomasum in young growing sheep

Abstract

1. Sixteen lambs were used to compare two methods of administering various protein supplements to weaned lambs. In one method the protein supplement was mixed with the dry feed, consisting mainly of rolled barley, so that it passed to the rumen. In the second method the supplement was suspended in water which the lambs were trained to suck from a bottle; the suspension then passed directly to the abomasum by way of the oesophageal groove and so escaped rumen fermentation.2. When the protein supplements were given in amounts that provided less than the estimated protein requirement of the animals, giving the liquid suspension led to significantly lower urinary nitrogen excretion (P < 0.001), greater nitrogen retention (P3. The body-weight gain was greater with white fish meal than with casein (P4. From a regression of nitrogen retention on nitrogen intake with lambs receiving the basal ration only, it was calculated that the improvement in retention of the protein supplement effected by giving it in liquid suspension was 31 % for casein, 27 % for fish meal and 24 % for soya-bean meal.