Effect of inorganic and organic zinc and copper supplementation on performance, nutrient utilization, rumen fermentation and blood biochemistry of kids

Abstract

Aim of the present study was to assess the effect of inorganic and organic zinc and copper supplementation on intake, nutrient utilization, performance, feed efficiency and hemato, blood biochemicals of kids. Barbari male kids(60) were randomly divided into 4 equal groups. Control group of kids were supplemented inorganic Zn and Cu (iZniCu), one group had organic Zn and Cu (OrZn-OrCu), while other groups had either inorganic Zn and organic Cu (iZnOrCu), or organic Zn and inorganic Cu (OrZn-iCu). Organic minerals were provided at 0.75 of their inorganic level. Growth, feed intake and feed conversion efficiency was similar in either form or combinations of Cu and Zn supplementation. The kids during 150 days of experimental feeding had live weight gain 8.6 to 8.8 kg and average daily gain 57.0 to 58.8 g. Kids consumed feed dry matter 618 to 710 g/d, which accounted 2.96 to 3.47% of live weight, with feed conversion ratio (kg feed/ kg gain) of 10.4 to 10.6 kg. Intake and digestibility of OM, CP and NDF were also similar among 4 groups. All kids had positive and similar N balance, which ranged from 8.1 to 9.9 g/d. Growing Barbari kids under present feeding protocol consumed 567 g feed and 14.3g nitrogen to have 59 g daily gain. Rumen fermentation characteristics studied at 4 h post feeding revealed that total volatile fatty acid contents were similar among 4 groups, whereas rumen fluid pH was lower and NH3-N was higher in OrCu and iZn fed, and TCA- ppt-protien was lower in OrCu and OrZn fed kids. Supplementation of organic Zn and Cu improved blood hemoglobin. Red and white blood corpuscles (WBC) counts were similar amongst 4 groups, but WBC decreased linearly with progress in feeding period. The lymphocytes, granulocytes, eosinophils, monocytes, mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration (MCHC) were similar. Kids fed OrCu and OrZn had lower protein, globulin and blood urea nitrogen content. Plasma Zn and Cu contents did not change, while plasma Fe content reduced in OrZn and Cu supplemented kids. It is concluded that kids may be fed diets with OrZn and Cu at 25% lower level than the required inorganic Zn and Cu during active growth phase without compromising performance. The combination of OrCu and iZn tended to promote feed DM intake per unit BW, reduced rumen fluid pH, and increased NH3-N level.