Feed intake in group housed pigs – considerations for breeding programs

Feed costs account for a large proportion of the costs of pig production representing usually around 50% of the total costs (Aranda and Cleary, 2001). in the Australian pig industry this proportion has been much higher recently due to the shortage of feed resulting from the extensive drought. Selection for feed efficiency is always an important topic, independent of the current drought situation. Most pig breeders in Australia do not record feed intake and therefore have no records for feed efficiency. Instead, breeders have focussed on growth rate and backfat and considerable gains have been achieved using BLUP technologies. Selection for growth rate and backfat will indirectly improve feed efficiency but its effect on feed intake depends on the main selection emphasis. A high growth rate is genetically related to a high feed intake whereas a low backfat is genetically associated with a low feed intake. Whether feed intake has actually been reduced will depend on the magnitude of selection emphasis put on growth rate (higher feed intake) versus backfat and feed efficiency (lower feed intake). The Australian payment system warrants putting a high emphasis on backfat (Cameron and Crump, 2001), which together with selection emphasis on feed efficiency may have led to a reduction in the feed intake capacity of the pig. Rex Walters has outlined in the previous talk what the implications of a low feed intake capacity are. It is the aim of this paper to summarise some of the main findings of previous Australian research, which has focussed on the growing pig and to outline areas where additional information is required to explore this important topic further.