Recent advances in sow nutrition to improve reproductive performance

Modern sows have been improved genetically and management technology for feeding strategies have been developed to increase sow productivity such as age of puberty, ovulation rate, embryo survival rate, mammary gland development, milk production, litter size, sow longevity and feed efficiency. Feeding strategies and nutritional manipulation for breeding pigs have to be changed as average performance has improved during different stages of the sow reproductive life. The sows have buffering ability on their conceptuses against dietary deficiencies during gestation, however, increased feed intake from 2.0 kg/d to 2.7 kg/d at d 80 of gestation reduces total litter weight and average pig weight. The exponential growth of mammary gland and mostly described by the concentration and total quantity of DNA and RNA during gestation occur after day 75. Excessive energy intake during gestation reduced mammary gland growth of gilts. No positive effect on total litter weight at birth was observed when increasing the feeding level over 1.8 kg/d or changing the feed allocation during the late pregnancy. Sow receiving 1.36 kg extra feed per day in the last 3 similar to 4 weeks of gestation had more live pigs at farrowing and heavier pigs at 12 d weaning. Feed restriction during lactation resulted in a low ovulation rate and a low embryonic survival in the following parity. Energy, protein and lysine intake positively affected the mammary gland growth for lactating sows. Higher energy consumption (3.5 Meal ME vs. 3.0 Meal ME/kg diets) showed higher protein, fat and DNA content in each suckled mammary gland. Other nutrients and feed additives such as fat addition, omega-3 fatty acid, organic chromium, vitamins and dietary fiber affect reproductive performance. In conclusion, nutritional and feeding strategies during puberty, gestation and lactation should be considered to maximize ovulation rate, litter size, mammary gland growth, milk yield and longevity during reproductive cycles in gilts and sows.