Sows that are both gestating and lactating during a 6-week lactation period should be fed on a high feeding level. To reduce the loss of body weight, a starch rich diet is preferred over a fat rich diet. A high feeding level (3.5 kg/d) after weaning until day 34 of gestation results in a better condition recovery of the sows than a standard feeding level (2.8 kg/d). This was shown in research that was conducted within the PPS Feed4Foodure by Wageningen UR on Swine Innovation Centre Sterksel.
On day 27 of lactation intermittent suckling started to induce lactational oestrus. During a period of 7 days, sows and piglets were separated for 10 hours per day. 77% of the sows showed oestrus within 6 days after the start of intermittent suckling and were inseminated. After insemination, intermittent suckling was no longer applied and sows remained with their piglets till weaning on day 42 after farrowing. From day 34 until day 42 sows were fed a starch rich or a fat rich diet lactation diet. From weaning (about 9 days after insemination) until day 34 of gestation sows were fed 2.8 kg/d (standard feeding level) or 3.5 kg/d (high feeding level) of a commercial gestation diet.
Weight loss (9 versus 13 kg) during the last 8 days of the 6-week lactation tended to be lower in the sows that were fed the starch rich diet. Body weight gain from weaning until the day of transfer to the farrowing room was higher in sows that were fed the high feeding level until day 34 of gestation (67.8 versus 59.0 kg). The number of live born and stillborn piglets was not affected by feed composition during lactation or by feeding level during gestation.