Effect of chelated minerals supplementation on copper and zinc absorption, retention and wool yield of chokla rams

An experiment was conducted to evaluate the beneficial effect of chelated copper (Cu) and zinc (Zn) minerals on absorption, retention and wool yield of rams. Twenty eight adult Chokla rams (4–5 year old) were randomly divided into four groups of 7 each. All the rams in the respective groups were stall-fed cenchrus grass hay (@ 800 g/head/day) concentrate feed (@ 400 g/head/day). Concentrate feed fed to rams of Group I (G-I) did not contain supplemental Cu and Zn, Cu- and Zn-sulphate (50% of basal diet) in Group II (G-II), Cu- and Zn- methionine (50% of basal diet) in Group III (G-III) and Cu- and Zn-methionine (25% of basal diet) in Group-IV (G-IV). Average body weights of Chokla ram at initiation of experiment was 33.01±0.84 kg and final body weights after 4 month of feeding were 41–42 kg with comparable body weight gains of 5.2 to 5.7 kg in all the groups. Dry matter, organic matter, crude protein, neutral detergent fiber, acid detergent fiber, hemicellulose and cellulose digestibility were comparable in all the groups and not influenced by supplementing chelated or non-chelated Cu and Zn. Average dry matter intake of rams was 1110 g and almost similar in all the groups. Digestible crude protein and metabolisable energy intakes were 63–69 g and 15–18 MJ/day, respectively and found similar in all the groups. Cu and Zn retentions were 5.68 and 10.78 mg/day in G-I, 8.86 and 14.79 mg/day in G-II, 13.40 and 18.04 mg/day in G-III and 11.00 and 14.34 mg/day in G-IV, respectively. Apparent absorption coefficients of Cu and Zn were 0.26 and 0.27 in G-I, 0.29 and 0.29 in G-II, 0.41 and 0.36 in G-III and 0.37 and 0.32 in G-IV, respectively. Serum Cu concentrations in G-I, G-II, G-III and G-IV was 0.76, 1.07, 1.06, 0.95 ppm and Zn concentration were 1.80, 2.23, 2.21 and 2.07 ppm, respectively. Wool yields of Chokla ram at six monthly clips in G-I, G-II, G-III and G-IV were 1233, 1292, 1282 and 1270 g, respectively. Zn contents of wool samples in G-I, G-II, G-III and G-IV were 120.43, 122.21, 111.19 and 107.92 ppm and corresponding values for Cu were 20.70, 21.01, 20.85 and 20.83 ppm. The results suggest that Cu and Zn from Cu- and Zn-methionine were more bio-available than Cu- and Zn-sulphate, however, their effects on wool yield and quality were not observed.