Last update: November 24, 2010 02:30:34 PM E-mail Print






JH Hoon

Grootfontein Agricultural Development Institute, P/Bag X529, Middelburg E.C., 5900

email : Jan Hoon

In any small stock enterprise, it is important to increase the kilograms of meat produced/hectare in order to increase ewe productivity and thus profitability. Strategic protein supplementation during late pregnancy and lactation can possibly be an economic sound method of enhancing traits such as weaning percentage, growth rate of Iambs, mortality rate of Iambs, etc. In South Africa, many studies have been done on protein supplementation of non-reproducing animals, but little information are available on the economy of supplementing reproducing ewes, especially with feed sources with a high rumen undegradable protein content. Different role players in the small stock industry (meat, wool and mohair) have therefore initiated a comprehensive study that are carried out in the small stock producing areas of South Africa. The aim of the study is to monitor the influence of supplementation of late pregnant and lactating ewes with protein sources with different levels of rumen undegradable protein (high vs. low) on production and reproduction and to determine the economic advantages of this practice in the different production areas of South Africa. The study is carried out on the farms of 16 participants (12 sheep and four Angora goat farmers), using their own animals. At each participant, the ewes were mated as one group, scanned for pregnancy and divided into three equal groups (control and two treatment groups) four weeks prior to lambing. The three groups were then placed into different camps, comparable in size, veld quality and quantity. A minimum of 70 ewes per group was used. The two treatment groups received a urea-based and bypass protein-based supplement respectively, at the recommended levels of 300g/ewe/day four weeks prior to lambing up until lambing and 400g/ewe/day from lambing until eight weeks after lambing, while the control group received no supplementation. The following data were collected: supplement intake, scanning percentage, weaning percentage, Iamb mortality rate, body weight of Iambs at 42 days of age and at weaning, body weight of ewes at mating and at 42-day Iamb age. The project will be carried out for a period of at least three years at all the localities and the animals will remain in their respective groups for the duration of the study. Preliminary results indicate no definite trend in favour of any of the groups with regard to the production and reproduction traits such as 42-day weight, weaning weight, conception rate, etc. At most of the localities, better results were, however, obtained in the two treatment groups, although the differences were very small in most cases. Little or no differences were observed between the two treatment groups, with some data favouring the bypass protein-based supplementation groups and others the urea-based groups. The above average rainfall that occurred during the periods of supplementation, with the resulting good grazing conditions, is most probably the main reason for the small differences that were observed between the different groups. The study is continuing and the economy of the different treatments at each locality will be determined at the end of the study.