Effect of precision feeding standardized ileal digestible lysine and other amino acids to lactating sows compared to conventional feeding strategies in a commercial farm

A total of 728 sows (Camborough, PIC) and litters (Camborough × PIC 800) were used in a lactation study to evaluate the effect of precision feeding Lys compared to providing a single lactation diet on sow and litter performance. Sows were blocked by parity and allotted to 1 of 2 treatments at entry into farrowing. Treatments consisted of a control treatment or blend treatment fed a low and high Lys diet to reach target standardized ileal digestible (SID) Lys intake for each day of lactation. Sows fed the blend treatment were fed a blend of a low (0.60%) and high (1.07%) Lys diet to reach target daily Lys intake via a computerized feeding system (Gestal Quattro Opti Feeder, Jyga Technologies, St-Lambert-de-Lauzon, Quebec, CA). Sows fed the control treatment received only the high Lys diet. The Lys level in the high Lys diet was increased by both soybean meal and feed-grade amino acids. Daily target Lys intake was based on NRC (2012) model estimates for litter size of 17 pigs, but levels were increased by 20% to reach an average target Lys intake of 61 g SID Lys/d for gilts and 65 g/d for parity 1 sows. Average Lys intake was 87% of target because sow average daily feed intake (ADFI) during lactation was lower than predicted. Sows fed the control treatment had greater (P < 0.001; 72.0 vs. 54.8 g/d) SID Lys intake than those fed the blend treatment. No differences (P > 0.10) in entry to wean (day 19) change in sow body weight (BW), backfat, loin depth, caliper score, or ADFI were observed between treatments. There were no differences (P > 0.10) in litter size at day 2 or wean; however, litters and pigs from sows fed the control treatment tended (P < 0.10) to have greater weight at wean and average daily gain compared to litters from sows fed the blend treatment. Control-fed sows had greater (P = 0.002) serum urea N concentration at wean compared to day 10 and to sows fed the blend treatment. Milk crude protein content was greater (P = 0.05) for control fed sows at day 10 and wean compared to sows fed the blend treatment. The decreased litter growth rate from blend-fed sows was likely due to insufficient Lys intake to maximize litter growth performance because when only considering the sows fed the blend treatment that achieved their target Lys intake, there were no differences in pig or litter weight at wean.