In the latest issue of Journal of Swine Health and Production, first-names author, H.M. Smith and co-authors at the University of Missouri report their work to evaluate the impact of day of farrowing induction on production parameters under commercial conditions (Analysis 1) and impact of induction, regardless of day, on production parameters (Analysis 2).

First- and second-parity sows (n=469) were induced with prostaglandin F₂α at 03:30 and 06:00 on gestation day 113, 114 or 116. Sows that had not farrowed by 05:30 the following day received 10 IU oxytocin.

Using Analysis 1, they found that gestation length (mean ± standard error) was 114.01 ± 0.08, 114.67 ± 0.08 and 115.19 ± 0.09 days for day 113, 114 and 116 groups, respectively. Spontaneous farrowing occurred in 6.50 per cent, 14.89 per cent and 80.83 per cent of sows. There was no treatment effect on number born alive (NBA), mummified, stillborns, litter weaning weight, litter average daily gain, percentage litters receiving medical intervention once, piglet mortality or percentage sows in oestrus by day 7 post-weaning.

Percentage of unsupervised piglets was greater (P=0.001) in day 116 (64.8 per cent) than day 113 sows (56.9 per cent), and intermediate in day 114 sows.

By Analysis 2, they observed that sows farrowing spontaneously had shorter gestation lengths (114.4 ± 0.09 days) than induced sows (114.7 ± 0.07 days; P=0.01). Other sow and piglet parameters did not differ between induced and spontaneous sows.

Smith and co-authors concluded that under the conditions of this study, more piglets are born during unsupervised hours when sows are induced on day 116 than when sows are induced on day 113. They add that gestation length must be known for successful farrowing induction.

Reference

^{Smith H.M., C.C. Selby, A.M. Williams, M.R. Ellersieck, W.R. Lamberson and T.J. Safranski. 2013. Effects of day of farrowing induction and spontaneous versus induced farrowing on sow and suckling piglet performance. J. Swine Health Prod. 2013;21(4):195–202.}

July 2013