Effect Of Cr-yeast And Leather Protein Meal On Growth Performance In Weaned-pigs And Study Of Its Principle

Forty healthy piglets,homogeneous for weight,parity and age,were used to assess the effects of chromium-yeast and leather protein meal supplementation on growth performance,blood parameters,stress and immune function in weaned-pigs. This experiment was in a completely randomized design. The result were showed as follow: (1)The supplementation of 0.02% Chromium-yeast significantly increased average daily gain (ADG)(+20.08% P<0.01);Groups of supplementing leather protein meal significantly increased average daily gain of weaned pigs (supplementation of 0.5% leather protein meal increased 19.51% P<0.01,supplementation of 1% leather protein meal increased 18.56%, P<0.05,supplementation of 1.5% leather protein meal increased 14.92,P<0.05). ;(2)diets with 0.02% Cr-yeast significantly increased average daily feed intake (ADFI) (P<0.05) ,but diets with leather protein meal had no significant effect (P>0.05) ;(3)Feed efficiency had the trend to increase in all treatment groups compared with that of control group,and diets with 0.5% leater protein meal had significant differences (P<0.05) ,others had no significant differences ( P>0.05 ) ;(4)Dietary 0.02% Cr-yease and 0.5% leather protein meal supplementation significantly decreased blood glucose,increased by 14.28% (P<0.05) and 14.21 % (P<0.05) respectively compared with that of control group,but dietary 1 % or 1.5% leater protein meal had no significant effect;(5)Diets with Cr-yeast significantly decreased blood urea nitrogen,by 30.05% (P<0.05) compared with that of control group.Leather protein meal supplementation had no significant effect on blood urea nitrogen(P>0.05) .Dietary Cr-yeast or leather protein meal supplementation did not affect serum proteins (TP,ALB);(6)Dietary 0.02% Cr-yeast and leather protein meal supplementation significantly decreased blood cholesterol level in weaned pigs,decreased by 18.37%(P<0.05 ) and 17.27% (P<0.05 ) respectively compared with that of control group.while diets with 1 % or 1.5% leather protein meal had no this effect;(7)Blood insulin concentration was not influenced significantly by dietary Cr-yeast or leather protein meal supplementation(P>0.05) ;(8)Diets with 0.02% Cr-yeast or 0.5%, 1%, 1.5% leather meal did not affect serum immunoglobulin G levels (P>0.05 ) ;(9)Blood cortisol concentration of weaned piglets were not influenced significantly by dietary Cr-yeast or leather protein meal supplementation in normal condition (P>0.05),but after ACTH was injected,blood cortisol concentration rised in groups with leather peotein meal of different levels and control group.Blood cortisol concentetion was lower in group with 0.5% leather protein meal than in control group and the difference was significant.Only blood cortisol concentration in group with 0.02% Cr-yeast kept in normal level,and was most significantly lower than that of control group.The results from this study indicated that 0.02% Cr-yeast and 0.5% leather protein mealhad similar effects on most indices measured.Both of 0.02% Cr-yeast and 0.5% leather protein meal had no effect on improving immune function and resisting weaning stress. Cr from Cr-yeast was more effective than Cr from leather protein meal in improving growth performance and resisting chemically induced stress. 1.5% leather protein meal and 1% leather protein meal had no effect on almost all indices measured.