Effects of late introduction of sows to two farrowing environments on the progress of farrowing and maternal behavior

¹ Institute of Animal Health, Welfare and Nutrition., Faculty of Agricultural Sciences, University of Aarhus, 8830 Tjele, Denmark

^* To whom correspondence should be addressed. E-mail: lene.juulpedersen{at}agrisci.dk.

	Abstract

To evaluate the effect of late introduction to farrowing pens on the progress of farrowing and maternal behavior, 20 primiparous and 20 multiparous sows were allocated randomly to 1 of 2 treatments 1) early introduction to pen (EP, n = 20) and 2) late introduction to pen (LP, n = 20). To evaluate the difference between loose housed sows and crated sows when introduced late to the farrowing environment a third treatment was included 3) late introduction to farrowing crate (LC, n = 20). Sow behavior and piglet birth intervals were recorded using video recordings from 16 h before the birth of the first piglet (BFP) until 48 h after BFP. Behavioral data were analyzed using Proc Mixed in SAS whereas the percentage of stillborn piglets as well as the response of the sow to piglet scream was analyzed using Proc Genmod in SAS. Before farrowing (16 h to 3 h before BFP) sows introduced late to pens had more postural changes per hour than sows introduced early to pens (LP = 12.7, EP = 8.9; P = 0.04), whereas there were no differences between sows introduced late to crates and sows introduced late to pens (LC = 14.2, LP = 12.7; P = 0.53). Inter-birth interval (P = 0.04), variation in the inter-birth interval (P = 0.01), and percentage of stillborn piglets (P = 0.003) were affected by an interaction between parity and treatment. In multiparous sows there were no differences between treatments (P > 0.18) either in the progress of farrowing or in the percentage of stillborn piglets. For primiparous sows, there were no differences (P > 0.22) between sows that were introduced late to pens and sows that were introduced early to pens. Primiparous sows that were introduced late to crates compared to pens had longer inter-birth intervals (LC = 29 ± 4.9 min, LP = 16 ± 2.9 min; P = 0.02), a greater variation of these intervals (LC = 35 ± 8.3 min, LP = 16 ± 3.6 min; P = 0.006), and a greater percentage of stillborn piglets (LC = 21 %; 95 % confidence interval ranging 14 to 30 %, LP = 5 %; 95 % confidence interval ranging 2 to 12 %; P = 0.004). After farrowing, neither postural changes, time spent in lateral lying, number of near crushing situations, nor the response to piglet scream test were affected by treatment (P > 0.09). When sows and gilts were introduced late to farrowing pens, neither progress of farrowing nor maternal behavior of importance for piglet crushing were influenced. However, crating primiparous sows that were introduced late to the farrowing environment compared to pen housing had detrimental effects on the progress of farrowing and the percentage of still born piglets.

Key Words: environment, farrowing pens, maternal behavior, sows, stillborn piglets