Comparison of on-farm progeny performances from local and imported boar semen used in the South African pig industry

D.A Krüger,H.E Theron,E Van Marle-Koster

doi:10.4314/sajas.v47i5.12

D.A Krüger, H.E Theron + Show 1 more

Open Access

https://doi.org/10.4314/sajas.v47i5.12

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Abstract

The widespread use of artificial insemination in the pig industry has provided breeders with access to genetic material from superior boars from around the world. Selection of parent stock is based on estimated breeding values (EBVs), which are regularly computed in all countries performing genetic evaluations. The purpose of this study was to evaluate the value of foreign sires in the South African (SA) pig industry by comparing the on-farm performances of progeny for average daily gain (ADG), feed conversion ratio (FCR) and back fat thickness (BF) from progeny sired by USA and Canadian born sires to the performance of progeny from local sires and to progeny with paternal USA grandsires (F1-US sires). The breeds analysed comprised of Duroc, Landrace and Large White pigs. Males outperformed females for all traits measured (P <0.0001). Large differences (P <0.0001) were observed between on-farm performances which had similar climatic regions for all traits except Duroc BF (P <0.05). Farm differences were consequently attributed to management rather than environmental influences. The effect of country was significant (P <0.05) in all the models tested with the USA-sired progeny having the best overall performance. However, as measured by a stepwise R2, country remained the smallest contributor to variation across all models (except BF in Landrace), with farm, sex and year-season contributing larger portions to the variation observed in the on-farm performances of progeny. These results indicate that most of the variation observed could be attributed to differences in farm as explained by management, rather than superiority of the imported boar semen.Keywords: Average daily gain, back fat thickness, feed conversion ratio, on-farm performance

Highlights

The South African pig industry is small compared to other livestock sectors, such as cattle or sheep
The influence of starting weight was only found to be significant (P
Except for BF in the Duroc and Landrace, end age had a significant influence on all the traits

Summary

Introduction

The South African pig industry is small compared to other livestock sectors, such as cattle or sheep. The breeding sector consists of only nine independent pig stud breeders, jointly contributing 27% to South Africa’s pig breeding stock (Streicher, 2013). The remaining 73% of the breeding stock in South Africa is supplied by two international breeding companies, TOPIGS and PIC (Buchanan & Stalder, 2011; Kirsten et al, 2009). South Africa has followed the global trend of using artificial insemination in the pig industry, with an estimated 70 to 75% of matings done through artificial insemination (AI) (Gerrits et al, 2005; Visser et al, 2014). Following the outbreak of Porcine Epidemic Diarrhoea virus (PEDv), all pig semen imports have been halted except for individual trade partners that have sufficient health measures in place to prevent the spread of PEDv (Department of Agriculture Forestry and Fisheries, 2014; Visser, 2015)

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