Effect Of Complete Pellet Diet With Different Nutritional Levels And Different Combinations On Fattening Lambs

This experiment was conducted to investigate the effect of complete pellet diets with two levels of DE and CP (factor A, A1, A2—0.9×, 0.8×NRC) and different diet combinations (factor B, B1, B2—with and without beet pulp) on crossbred male lambs (3~3.5 months age) of Borderdale (♂)×Mongolian (♀) (C1:16 lambs) and Poll Doset (♂)×Mongolian (♀) (C2:12 lambs). A 2×2×2 factriol designing and 28 lambs which they were divided into four groups (A1B1,A1B2,A2B1,A2B2) were used in the experiment.The results of feeding trial indicated that there were no significant difference (P>0.05) on ADG of lambs between two treatments for the factor A,factor B, factor C and their interaction, except that during the first 20 days, the ADG of C2 was higher than that of C1 (P<0.05). Compared with A2, the intake of lambs fed on A1 was higher (P<0.01), but the FCR of A2 was much lower (P<0.01). During the last 20 days of the trial, a tendency indicated that the ADG of B1 was higher than that of B2. The results of digestion and balance were as follow:(1) the DMI,OMI,DMF and OMF of A1 was much lower (P<0.01) than that of A2, but the DMD and OMD was significantly higher (P<0.01) than that of A2. There was no significant (P>0.05) difference on DMD and OMD between B1 and B2. The DMD (P=0.077) and OMD (P=0.080) of C1 were higher than that of C2. The significant (P<0.05) effect of the interaction of factor A and factor B on DMI and the quantity of digested DM were observed, and A2B1 were highest. (2) A1 was lower than that of A2 on TNI (P=0.097) and UTN (P=0.079). There was no significant (P>0.05) effect on nitrogen metabolism bewteen B1 and B2. The quantity of digested N (P=0.113) and retentive N (P=0.138) of C1 were higher than that of C2. (3) Factor A unaffected (P>0.05) on the ADFD and CELD, but the ADFI and CELI of A1 were significantly (P<0.01) lower than that of A2. The ADFI,CELI (P<0.01) and ADFD,CELD (P<0.05) of B1 were significantly lower than that of B2. The ADFD (P=0.082) and CELD (P=0.089) of C1 were higher than that of C2. The significant (P<0.05) effect of the interaction between factor A and factor B on ADFI was observed, and A2B1 was highest. (4)No significant (P>0.05) effect of factor A on CaD and PD was find. The quantity of feces' Ca and feces' P (P<0.05) of B1 were much lower than B2, but the PD of B1 was significantly higher(P<0.05) than that of B2. The CaD and PD of C1 were significantly higher(P<0.05) than that of C2.The results of slaughter experiment showed that it were no significant(P>0.05) effect of factor A,factor B,factor C and their interaction on lamb carcass weight (they were 16.33,15.75,16.08,15.92Kg, respectively) and their carcass yield (they were 47.31%,46.62%,46.57%,47.00%, respectively). The cooked meat rate of A1 were much higher (P<0.01) than A2; The GR value of B1 was lower (p=0.183) than that of B2.