Effects of Source of Supplemental Zinc on Performance, Nutrient Digestibility and Plasma Mineral Profile in Cashmere Goats (Report‪)‬

INTRODUCTION Zinc (Zn) is an essential element required by ruminants for a number of biochemical functions. Early work suggested that Zn deficiencies can affect growth, reproduction, immune system and gene expression in ruminants (Underwood and Suttle, 1999). In recent years, use of organic Zn for supplementation of ruminant diets has increased but whether organic forms are more effective than inorganic forms remains controversial. For example, Garg et al. (2008) observed significantly improved ADG and feed efficiency in lambs given ZnMet compared to a ZnS[O.sub.4]-supplemented group. Puchala et al. (1999) found that ADG was greater for Angora goats supplemented with ZnMet compared to a ZnO group. In contrast, Nunnery et al. (1996) reported that ADG by steers supplemented with ZnS[O.sub.4] was 7.4% greater than those supplemented with ZnMet, but feed intake and efficiency were similar. Galyean et al. (1995) reported no differences in ADG and feed efficiency in steers fed ZnO or ZnMet. Similar results were also observed in Angus and HerefordxAngus heifers (Spears and Kegley, 2002).