The effects of sire type on reproduction, production performance and carcass quality of pigs
This study was jointly funded by the Pig Production Development Committee (PPDC) and the Department of Agriculture and Rural Development for Northern Ireland (DARD), and undertaken by staff at the Agricultural Research Institute of Northern Ireland. The aim of this work was to evaluate different sire types available in Northern Ireland.
To ensure the results were representative of genetics across Northern Ireland, three main semen suppliers were used: Elite sires; Deerpark Pedigree Pigs; and Hermitage AI. As the objective of the study was to evaluate the effects of sire type, not breeder, all data were pooled across companies. A total of 720 dams (21% first cross Landrace x Large White, 67% ¾ Landrace and 12% pure Landrace) were inseminated during the experimental period, November 1998 to July 2000. Eight sire types were evaluated; 3 purebred and 5 crossbred. There were no effects of purebred versus crossbred sire on reproductive performance or on production performance of progeny. The only carcass evaluation parameter affected was V measurement (backfat thickness at the edge on the eye muscle) which was 2 mm thicker for the progeny of crossbred sires. Meat from pigs of purebred sires contained a higher level of intramuscular fat than that from crossbred sires (2.65 vs. 2.11% respectively).
There were inconsistent effects of individual sire type on performance, carcass quality and meat quality. The main finding arising from this work is that the variation between sires within a sire type is greater than the variation between sire types. For example, there was a variation of greater than 25% for production performance between the top 15% and bottom 15% of pigs. There were also wide variations in carcass and meat quality parameters e.g. % fat in the tail ranged from 25.7 to 69.1% for the top and bottom 10% of pigs respectively.
The results also demonstrate a lack of relationship between P2 values and eye muscle area and depth (r=-0.03 and -0.01 respectively) which suggests that carcass characteristics other than P2 values need to be included in the selection of breeding animals. Similarly, the weak correlations between carcass and meat quality parameters (r<0.3) indicate that if meat quality is to be improved, it must be specifically included in the selection process.
Finally, although the study was designed to examine the effect of sire type there is evidence to suggest that the sow may also contribute to the variation observed in performance within this study. The challenge in pig production is to reduce this variation by the identification and selection of individual sires and sows in order to attain optimum performance and high carcass and meat quality