Voluntary feed intake by lactating sows

Data from 3559 lactations in the Moorepark herd over a seven-year period were analysed. An increase in intake was associated with increasing litter size, increasing parity and lower pregnancy weight gain. Higher farrowing house temperatures were associated with lower intakes resulting in sows farrowing in July eating 10% less than sows farrowing in mid-winter. Higher weaning age was also associated with increased consumption. Review of the literature shows a number of other factors to be associated with variation in intake including breed of sow, system of feeding and system of sow management. Intake of higher energy diets is sometimes depressed but energy consumed may be increased. Sows fed low protein diets in pregnancy consume more of high protein diets in lactation but this is not so when a high protein pregnancy diet is fed.