Comparative effects of low levels of dietary cobalt and parenteral injections of Vitamin B 12 on body dimensions in different breeds of Omani goats

Abstract

The effect of low levels of dietary cobalt and parenteral Vitamin B 12 supplementation on live body weight and the body dimensions of three breeds of Omani intact male goats, namely Batina (14 goats), Dhofari (14 goats) and Jabal Al-Akdhar (14 goats). The animals were fed Rhodes grass hay and a commercial diet containing 0.10 and 0.12 mg/kg DM of cobalt, respectively, from week 9 (weaning age) to week 48. At weaning, the kids were divided into control and treated groups. At week 9, the kids in the treated group were injected subcutaneously with 2000 μg of hydroxocobalamin (Vitamin B 12) and thereafter at 8-week intervals to week 48 of age. Serum Vitamin B 12 levels and various measurements of live body dimensions were determined on week 10, and then at 4-week intervals until 48 weeks of age. Serum Vitamin B 12 levels were significantly higher ( P < 0.01) in treated goats than control goats throughout the course of the experiment. The serum levels of Vitamin B 12 for the control group declined to levels below 200 pg/ml consistent with those of lambs considered to have a deficiency of Vitamin B 12. Body measurements such as body length, and rump and wither heights were more affected by Vitamin B 12 injection than rump and wither widths. At the end of the experiment (week 48), control animals were about 89% of the live body weight of the treated group. The overall body length of the control group was 92.7% of the body length of the treated animals, whereas rump height, rump width, wither height and wither width were 93.5, 87.6, 96.7 and 90.4% of the treated animals, respectively. The Jabal Al-Akdhar breed had significantly heavier body weight and greater body dimensions than the Batina and Dhofari breeds irrespective of treatment. This study indicated that injection of Vitamin B 12 improved live body weight and also enhanced the body growth of cobalt deficient goats. To insure normal growth and development of goats, serum Vitamin B 12 levels must be maintained at above 350 pg/ml.