Whole wheat grain feeding of lambs. IV.* Effects of an antibiotic, lactic acid, grain moistening and restricted intake on wheat sickness of young sheep

Abstract

Two studies are reported in which young lambs were changed rapidly from roughage diets to whole wheat diets and subjected to various treatments aimed at facilitating adaptation to the wheat diet. In pen feeding studies, groups of three sheep with rumen cannulae were used to investigate the effects of the various treatments on wheat sickness. The treatments included intraruminal administration of sulphadimethoxine before and during wheat feeding; moistening; and restriction of grain intake. The studies indicated that except perhaps for restriction of intake, none of the methods used was successful in reducing the build-up of lactic acid and decline in rumen pH and therefore wheat sickness. Sulphadimethoxine did not have a major effect on volatile fatty acid or lactic acid production when wheat grain was consumed. In an antibiotic dose response trial, 59 lambs were changed from roughage to wheat grain diets, restricted amounts of wheat grain with sulphadimethoxine being offered at four levels (0, 45.4, 136.3 and 272.7 mg/kg liveweight). The drug proved to be toxic and the lamb mortality (5, 23, 39 and 62%) rose as the dose increased. Results are discussed in relation to metabolic and practical aspects of wheat grain feeding of lambs and the need for further work to seek practical means for regulating intake under group feeding conditions. *Part III, Aust. J. Agric. Res., 24: 425 (1973).