Factors associated with farrowing assistance in hyperprolific sows.

The present study was performed to determine risk factors associated with the frequency of farrowing assistance in hyperprolific sows in a tropical environment and to investigate the impacts of farrowing assistance on piglet colostrum consumption and sow colostrum yield. Farrowing data from 352 Landrace × Yorkshire crossbred sows and 5,554 piglets in five commercial swine herds in Thailand were investigated. The sows were classified according to parity numbers: 1 (n=72), 2-4 (n=128), 5-6 (n=84), and ≥7 (n=68) and the total number of piglets born per litter (TB): 10-13 (n=90), 14-16 (n=117), and ≥17 (n=145). The incidence of farrowing assistance and associated parameters were investigated. The TB and farrowing duration averaged 15.8±0.2 and 279.9±11.2 min, respectively. The percentage of sows that required farrowing assistance was 29.8% and varied among herds from 5.7 to 53.3% (p<0.001). The percentage of piglets born after birth assistance using manual intervention was 8.4%. Sows with parity numbers 1 and 2-4 had a lower frequency of farrowing assistance than sows with parity numbers ≥7 (p<0.01). The colostrum yield of sows that required farrowing assistance did not differ from sows that farrowed without assistance (5.3±0.2 and 5.1±0.1 kg, p=0.288); however, the colostrum consumption of piglets born from sows that required farrowing assistance was lower than those born from sows that farrowed without assistance (302.2±15.7 and 354.2±5.6 g, p<0.001). Blood oxygen saturation of the piglets born after birth assistance tended to be lower than the piglets that farrowed without birth assistance (87.8±1.3 vs 90.4±0.4%, p=0.054). The frequency of farrowing assistance in sows varied among herds and was influenced by parity number. The piglets born after receiving birth assistance should receive special care to improve their blood oxygen saturation and enhance colostrum intake.