184 Increased feeding level in peak lactation is an effective tool to control body weight loss in hyper prolific sows

Research has shown that feed restrictions in late lactation can increase BW loss and affect subsequent reproduction. Therefore, this study was designed to determine how increasing maximum daily feed allowance (MDFA) in late lactation and litter size (LS) affected body weight (BW) and back fat (BF) loss, and subsequent reproduction in sows nursing above 12 piglets. A total of 619 DanBred sows (parity 1 to 5) were randomly assigned to 1 of 6 treatments combining 2 levels of LS (12 or 14 piglets) and 3 levels of MDFA (6.17 kg; 7.20 kg; 8.23 kg; DM basis). Maximum feed allowance was achieved at d 15 and kept constant to weaning at d 24. The diet was formulated to contain 11.2 MJ NE/kg DM and to comply with all AA according to Danish recommendations. Sows were fed 3 times a day. Standardization of litters were done within 48 h after farrowing. Sows were weighed and BF measured in P2 at litter standardization and at weaning to calculate BW and BF loss during lactation. In total, 543 of 619 sows with 0 or 1 dead piglet during lactation were included in the data, and linear mixed models were used for data analysis. No interaction between LS and MDFA was found (P > 0.05). Loss of BW (16.2 kg and 21.0 kg; P < 0.0001) and BF (2.42 mm and 2.94 mm; P < 0.0001) increased when LS increased from 12 to 14 piglets, respectively. Increasing MDFA reduced BW loss from 24.5 kg to 18.3 kg to 13.0 kg (P < 0.0001), whereas BF loss decreased from 3.0 mm to 2.8 mm to 2.3 mm (P < 0.0001). Subsequent farrowing rate and total born piglets in the next litter were unaffected by MDFA (P = 0.149 and P = 0.527, respectively). In conclusion, BW and BF loss of lactating sows can be controlled efficiently by increasing MDFA in peak lactation.