- Hair production, reproduction and income of Angora goat ewes that had six kidding opportunities
Hair production, reproduction and income of Angora goat ewes that had six kidding opportunities
J.H. Hoon1 & M.A. Snyman1
1Grootfontein Agricultural Development Institute, Private Bag X529, Middelburg EC, 5900, South Africa.
Background: As with all biological traits, there are also differences among animals in their ability to maintain higher levels of production throughout their flock life. To maximise current flock income, it is important to keep ewes in the flock that are able to maintain a high level of mohair production and reproduction until the end of their flock life. Angora ewes are usually kept in the flock until the age of six or seven years.
Aim: The aim of this study was to determine the range in hair production, reproduction and income of Angora ewes that had six kidding opportunities in the flock. Furthermore, the relative contribution of hair production and reproduction to income of these ewes was also investigated.
Methodology: The project protocol was approved by the Ethical Committee of the Grootfontein Agricultural Development Institute (GVE/AP2/18). Data collected on the flocks of three South African Angora goat producers from 2000 until 2015 were included in this study. The following production data were recorded on the kids: Body weight at 12- and 16 months of age, as well as fleece weight, fibre diameter profile, style and character at the second and third shearings. Full reproduction data, body weight before mating as well as fleece weight, fibre diameter profile, style and character at the winter shearing were recorded on the ewe flocks. For all the analyses, only ewes in the dataset that had 6 (682 ewes) kidding opportunities (7 years of age) were included. Income per ewe was calculated as hair production income and reproduction income. Early and adult production and reproduction traits of the Top 100 and Bottom 100 ewes according to total lifetime income were compared. The relationships among the hair production and reproduction income and total yearly income were also determined. The ewes were also divided into four categories on the basis of their total yearly income and the relative sources of income for these ewes were compared.
Results and Discussion: Comparing the early and adult production and reproduction traits of the ewes in the Top 100 and Bottom 100 categories (lists according to yearly income) indicated significant differences in early fleece weight, fibre diameter, body weights and maiden ewe reproduction between the two groups. It is however, noteworthy that adult fleece weight and yearly fleece income did not differ between the Top 100 and Bottom 100 ewes. The main difference in total yearly income between ewes was due to differences in yearly reproduction income. Yearly hair production income was nearly the same for ewes in all categories. Reproduction income contributed more to total income in ewes in the top 25% income category compared to ewes in the bottom 25% category.
Conclusion/recommendations: Differences in total yearly income of ewes are largely due to differences in reproduction. These differences could be exploited by placing selection emphasis on those traits that contribute most to yearly income and for which high levels of production can be maintained until an older age. Selection of young ewes should be focussed on early body weight, number of kids produced and total weight of kids weaned at the first parity.
Proc. 51st Congr. S. Afr. Soc. Anim. Sci. Bloemfontein. 10-12 June.