Improved udder access prolongs duration of milk letdown and increases piglet weight gain

Nursing-suckling behaviour and piglet weight gain were compared in traditional Danish farrowing crates and farrowing pens where sows were free to roam to determine if improved access to the udder could increase the milk intake of the piglets. The experiment was conducted in a Danish production herd, and behaviour and weight gain were registered on day 14, 15, 27 and 28 post-partum. The nursing-suckling behaviour was video recorded, and the duration of the milk letdown was used as an indicator of the milk intake of the piglets.The milk letdown lasted 8.5 s for the sows housed in crates and 10.3 s for the sows housed in farrowing pens. The 1.8 s longer duration (P < 0.001) could be due to more peaceful piglets and calmer sows in the farrowing pens; the piglets had fewer teat fights (P = 0.009) and less piglets missed the milk letdowns (P < 0.001). The sows housed in farrowing pens terminated fewer nursings (P < 0.001), and thereby allowed the piglets to post-massage longer (P < 0.001). Litter size did not influence the duration of milk letdown. The piglets housed in the farrowing pens had a higher weight at day 28 post-partum (P = 0.019) compared with the piglets housed in crates. The higher weight indicated that the piglets in the farrowing pens with easier access to the udder had a higher milk intake.