Evaluation of Basic Zinc Chloride as a Zinc Source for Cattle

Abstract

Two trials were conducted to evaluate basic zinc chloride as a zinc source for cattle. In Experiment 1, 120 Angus cross steers were used to determine the effects of zinc level and zinc source on performance and carcass characteristics. Treatments consisted of 1) control (no supplemental zinc), 2) 30 ppm supplemental zinc from zinc sulfate, 3) 90 ppm supplemental zinc from zinc sulfate, 4) 30 ppm supplemental zinc from zinc chloride, and 5) 90 ppm supplemental zinc from zinc chloride. Carcass data was obtained from a USDA grader 48 h after slaughter. Zinc supplementation regardless of source, lowered gain and gain:feed (P < 0.05) in the growing phase. During the growing phase steers supplemented with 30 ppm from zinc sulfate gained faster (P<0.05) than those fed 30 ppm of zinc from basic zinc chloride. In the finishing phase zinc supplementation, regardless of level or source, did not affect gain, feed intake or gain:feed. All carcass characteristics were similar for all treatments except for marbling, which was slightly higher (P<0.05) in steers supplemented with 90 ppm compared to those fed 30 ppm of zinc. Liver zinc was also significantly (P < 0.05) higher in steers fed 90 ppm verses 30 ppm of zinc. Plasma zinc concentrations were higher for steers supplemented with 30 ppm zinc from basic zinc chloride on day 28 and for steers supplemented with 90 ppm zinc from basic zinc chloride on day 84 of the growing phase and day 56 of the finishing phase compared to those fed similar concentrations of zinc from zinc sulfate. Steers supplemented with 90 ppm of zinc also had higher plasma zinc concentrations than those supplemented with 30 ppm of zinc on day 84 of the growing phase and day 56 of the finishing phase. Ruminal soluble zinc concentrations were increased by zinc supplementation of the control diet and were higher in steers supplemented with 90 ppm compared to 30 ppm. Steers supplemented with 90 ppm of zinc from zinc sulfate had higher ruminal soluble zinc concentrations than steers fed 90 ppm from basic zinc chloride. Plasma alkaline phosphatase activity was not affected by zinc during the growing phase, but was higher in steers supplemented with 90 ppm zinc from basic zinc chloride compared to those fed a similar concentration of zinc sulfate on day 56 of the finishing phase. Results indicate that zinc sulfate and basic zinc chloride produce similar performance when fed to growing and finishing steers.

In Experiment 2, 16 steers were randomly separated into two groups. Four Angus steers and 4 Simmental steers were in each group and fed a diet low in zinc (25 ppm) for 14 days. The 2 groups were then supplemented with 25 ppm zinc from either zinc sulfate or basic zinc chloride. After 4 days of consumption of supplemental zinc, steers were placed in stainless steel metabolism crates and total fecal and urine were collected for a 5 day period. Steers were fed to minimize orts and refusals were weighed and analyzed. Plasma zinc concentrations were higher for steers supplemented with basic zinc chloride. Steers supplemented with basic zinc chloride also had higher apparent zinc absorption and retention than those supplemented with zinc sulfate. Results indicate that zinc from basic zinc chloride was more bioavailable than from zinc sulfate.