PSII-18 Dietary Strategy for Gilt Development

The objective was to determine a dietary strategy for gilt development that would improve reproductive performance. One thousand eighty-three gilts (DNA) were blocked by weight (average initial weight = 27.5 ± 4.8 kg) and allocated to one of four dietary treatments (267-273 gilts per treatment). Treatments included: 1) standard grower/finisher (SGF) diet; 2) maximize bone growth (MB) diet with increased available P and Ca; 3) maximize growth (MG) diet with increased energy and AA levels, or 4) maximize both bone and growth (MBG) diet. Each treatment had five phases with all gilts fed a common gestation diet after insemination. At 20 weeks of age, gilts fed MG and MBG diets were heavier (P < 0.05) than gilts fed other diets. Gilts fed the MG diet were heavier (116.9 kg; P < 0.05) at 23 weeks (start of boar exposure) than gilts fed other diets (SGF, 112 kg; MB, 110.3 kg; MBG, 114.6 kg). Gilts fed the MG diet were heavier (143.8 kg; P < 0.05) at mating (29 weeks of age) than gilts fed other diets (SGF, 139.0 kg; MB, 136.8 kg; MBG, 139.6 kg). Upon entering farrowing stalls, gilts fed the MG diet continued to be heavier (P < 0.05). More gilts farrowed (P < 0.05) when fed the MG diet (MG, 89.8%; MBG, 86.8%; MB, 82.2%; SGF, 81.9%). Dietary treatment had no impact on number of pigs born alive per litter, total pigs born per litter, or piglet birth and weaning weights. There was a tendency (P < 0.10) for gilts to remain in the sow herd to farrow their second litter when fed either the MG or MBG diet. Overall, feeding higher energy and AA levels to maximize growth increased gilt development weights, improved the number of gilts that farrowed, and tended to increase sow retention.