Last update: November 19, 2010 12:10:24 PM E-mail Print

 

Trace mineral supplementation of sheep and Angora goats

in the different grazing areas of South Africa

 

J.H. Hoon and M.J. Herselman

 

Grootfontein A.D.I., Private Bag X529, Middelburg (EC), 5900

Corresponding author: Jan Hoon

 


The aim of the study was to determine the effect of supplementation of sheep and Angora ewes with a commercial trace mineral supplement on reproduction rate of ewes and growth rate of lambs/kids, in order to establish guidelines and make recommendations that will benefit producers financially. This project was carried out at 20 localities (13 sheep and 7 Angora goats) in the small stock producing areas of South Africa. At each locality, a flock of ewes was randomly divided into two groups (control and treatment). The ewes of the treatment group received a 1 ml subcutaneous injection of a commercial trace mineral supplement containing Zn, Mn and Se (Multimin® - Virbac) 4-6 weeks prior to mating and again 4-6 weeks before lambing/kidding. All the ewes were managed as one group for the duration of the study. All the procedures were repeated for two/three consecutive years with the same nucleus of animals at each locality. The following data were recorded at all the localities: body weight of lambs/kids at 42-day age and at weaning and weaning percentage. An economic analysis was done on the combined data obtained from the sheep and Angora goat localities, using the SM2004 model, to determine the economic viability of trace mineral supplementation of ewes. From the results it appeared that supplementation of Zn, Mn and Se by means of a commercial product had in general a positive effect on the measured reproduction traits of sheep and Angora ewes and the production traits of their lambs/kids, although differences were relatively small at most localities. The economic analysis indicated that the supplementation of Angora goats and sheep with a commercial trace mineral supplement was economically viable. It also indicated that an increase of 0.4-0.5% in the weaning percentages of Angora goats and 0.7-0.8% in the weaning percentages of sheep, was sufficient to cover the cost of the supplementation.