The effect of the level of nondegradable protein on digestibility of nutritive substances in fattening lambs

Results of the investigation of the effect of the level of non- degradable protein in concentrate mixtures on digestibility of nutritive substances in fattening lambs are presented in this paper. Physiological research included 18 male lambs crosses Pirot Pramenka x Wurttemberg x Ile de France, average body mass of approx. 35,0 kg, divided into three groups. Lambs were fed iso-protein concentrate mixtures which differed in relation to share of protein non-degradable at the rumen level: 43% (I), 51% (II) and 58% (III). Trial results indicate that the level of protein adoption was not under the influence of investigated treatment, considering that digestibility coefficients were: 52,58% : 51,30% : 55,12%. With the increase of share of non- degradable protein in concentrate mixtures (43: 51: 58%), also tendency of increase of fat digestibility was observed: 76,13 : 77,98 : 87,17%, but decrease of degree of cellulose digestion: 67,40 : 45,87: 22,39% and NFE: 83,87 : 76,05 : 82,96%.