Study On The Zinc Requirement Of Growing Inner Mongolian White Cashmere Goats

In this paper, the comprehensive and factorial methods were used to determine the zinc requirements of the growing Inner Mongolian White Cashmere castrated bucks during the telogen and anagen periods.Part1(the telogen period): Effects of four dietary zinc levels ( 28.23mg/kg for groupâ… ,50mg/kg for groupâ…¡,70mg/kg for groupâ…¢,100mg/kg for groupâ…£) on serum Zn concentration, digestibility and metabolism of nutrients and productive performance of Cashmere castrated bucks during the telogen period were studied in this part. The results showed that:â‘ the zinc supplementation in the basal diet had significant influence on serum Zn concentration (P<0.05), but the difference between groupâ…¡,groupâ…¢and groupâ…£was not significant (P>0.05);the serum CuZn-SOD enzyme activity was enhanced with the elevation of dietary zinc levels.â‘¡Dietary Zn levels had no significant influence on N metabolism and DM digestibility (P>0.05). NDF and ADF digestibilities of groupâ…¡andâ…¢were significantly higher than groupâ… (P<0.05),but the difference between groupâ…¡andâ…¢was not significant (P>0.05). There are linear regression relationship between Zn intake and Zn excretion, and the regression equation as follows: y = 0.7914x + 0.0793(R2 = 0.9697 P=0.0001 n=9); the Zn maintenance requirement of the Cashmere Goats during the telogen period was 0.0793mg/d/kg LW.â‘¢The zinc supplementation in basal diet had significant influence on average daily gain(ADG) and feed conversion efficiencies, the values in groupâ…¡andâ…¢were significant higher than in groupâ… andâ…£(P<0.05), but the difference between groupâ…¡andâ…¢, groupâ… andâ…£were not significant (P>0.05); 98.04mg of dietary Zn was retented when the Cashmere Goats during the telogen period gained 1kg body weight gain and 103.25mg of dietary Zn was retented when Cashmere Goats during the telogen period gained 1kg fleece daily.The optimal Zn dietary level in diet of Cashmere Goats during the telogen period was 50mg/kg determined by the method of comprehensive experiment; the Zn net requirements of Cashmere Goats during the telogen period was 7.694mg/d estimated by the factorial method.Part2(the anagen period): Effects of four dietary zinc levels(28.23mg/kg for groupâ… ,50mg/kg for groupâ…¡,70mg/kg groupâ…¢,100mg/kg for groupâ…£) on serum Zn...