1. The impact of predation on a sheep enterprise in the Free State region
Andries Strauss1,
Prof. H.O. de Waal2 & Dr. N.L. Avenant3
1 Agricultural Research Institute, Private Bag X01, Glen 9301, South Africa,
2 Department of Animal, Wildlife and Grassland Sciences, University of the Free State, Bloemfontein, 9300, South Africa.
3 Department of Mammalogy, National Museum, POBox 266, Bloemfontein, 9300, South Africa.

2. Introduction Canis mesomelas Caracal caracal Canis familiaris
Most livestock
Losses in SA
(Avenant et al., 2006; De Waal et al., 2006).
Glen Agricultural Institute (Glen AI)
Private sheep farms,SA

3. Allocated to four (4) system treatments Free State Wool Sheep Project
Introduction
Started in 1998
A total of 280 Merino Ewes
Allocated to four (4) system treatments
Free State Wool Sheep Project
Treatment
SL-V(C)
Spring Lambing season on Veld with a salt (NaCl) lick only (control)
SL-V&S
Spring Lambing season on Veld with Supplementary feeding
SL-R&V
Spring Lambing season on irrigated Rye-grass (Lolium multiflorum and L. perenne) and Veld
AL-O&V
Autumn Lambing season on Oats (Avena sativa) pasture in winter and Veld in summer and spring

4. Aim of FS Wool Sheep project 1998To
Develop
and
wool farming systems
on the resource (veld & pastures) combination
of Glen AI
sustainable
profitable

5. PROBLEM

6. PREDATION FS Woolsheep project 4 Merino flocks Included in Analysis
Merino shearing flock &
Dorper flock (De Waal & Combrinck, 2000)
Included in Analysis

7. To determine the impact of
New study developed:
Aim:
To determine the impact of
Of the Merino and Dorper flocks
over a 9 year period
from 1999 – 2007
at Glen AI
Reproduction
Predation
Production
Economy

8. Test population Started in 1998 with 1130 sheep Four(4) treatment
flocks of FS
Wool Sheep
project
Merino
shearing
flock
Dorper flock
552 Sheep in 2007

9. Research process
Comparison between four categories of losses:
Predation
Diseases
Metabolic disorders / accidents
Theft
Calculations included:
Direct financial costs
Veterinary and shearing costs
Lick and labour
Pastures

10. Data Collection
Analysis of small stock death certificates

12. Annual post-weaning losses and mortalities (Merino flocks & Dorper flock) over a period of nine years at the Glen AI

13. Annual post-weaning losses as a percentage of all sheep (Merino and Dorper) flocks over a period of nine years at the Glen AI

14. Direct financial implications of losses and mortalities (Merino & Dorper flocks) over a period of five years at the Glen AI

15. Total financial expenditure due to fruitless expenses (Merino & Dorper flocks) at the Glen AI

16. Annual financial losses for the Merino flocks and the Dorper flock at the Glen AI

17. Conclusion Theft 6% Metabolic disorder & Accidents 20% Predation 72%
(R9 843/year)
Theft 6%
(R35 299/year)
Metabolic disorder &
Accidents 20%
(R /year)
(R4 337/year)
Predation 72%
Diseases 2%

18. Total Merino and Dorper flock size
1130
A loss of 747
suckling lambs
Over 9 year
period +
A loss of 1422
post-weaned lambs =
Total
lost to Predation
552

19. Due to Predation some of the ewes in the Merino flocks and Dorper flock at the Glen AI could not raise one lamb in a six year production cycle

20. Aim of FS Wool Sheep project 1998To
Develop
and
wool farming systems
on the resource (veld & pastures) combination
of Glen AI
sustainable
profitable

21. The R lost due to predation is very high if considered that the data was collected on a relative small number of sheep in the Merino and Dorper flocks at the Glen AI.
The genetic losses due to predation are estimated as considerably more than the direct financial losses.

23. Den Own territory Shedding Teeth Mating Weaning 1999-2007 2008-2011
64 days pregnant
Den
Own territory
Shedding Teeth
Mating
Weaning

24. References
Avenant, N.L., De Waal, H.O. & Combrinck, W.J., The Canis-Caracal Programme: A holistic approach. In: Proceedings of a workshop on Holistic Management of Human-Wildlife Conflict in the Agricultural Sector of South-Africa. Ganzekraal Conference Centre, Western Cape, South Africa. pp
De Waal, H.O. & Combrinck, W.J., The Dorper - its nutrition and a perspective of the grazing ruminant on veld. Small Ruminant Research 36,