Last update: March 2, 2011 09:17:15 AM E-mail Print



Investigation into the effect of vitamin A supplementation on the reproduction of sheep and goats



PG Marais


Grootfontein ADI, P/Bag X529, Middelburg (EC), 5900


In South Africa vitamin A supplementation is widely recommended and used extensively in practice, both by farmers and by the feed industry. This situation prevails despite the fact that it appears that no conclusive evidence, indicating that such supplementation hold any benefit in terms of small stock performance, exits. A study was therefore conducted under different environmental conditions to determine the effect of vitamin A supplementation on reproduction and production of sheep and goats. The study was conducted with sheep and goats on four Experimental Stations (Grootfontein, Adelaide, Upington and Koopmansfontein). The project started in 2001 with Merino and Dorper sheep, Boer goats and Angora goats and was repeated over four years. At the start of project, a flock of ewes was randomly divided into two groups (control and treatment). At each locality, the ewes were mated as one group. The treatment group received a 0.25 ml (125 000 i.u) injection of a commercial vitamin A product (Provit A, Virbac) 4 - 6 weeks prior to mating and again 4 - 6 weeks before lambing. A minimum of 50 ewes per treatment was used and all the ewes were managed as one group for the duration of the study. Differences in reproduction and body weight at birth and weaning occurred between years at the same locality and it was evident that vitamin A supplementation had no effect on reproduction and production traits measured.



S. Afr. J. Anim. Sci. 27, 55