Effects of repeated cross-fosterings on preweaning behavior and growth performance of piglets and on maternal behavior of sows.

Abstract

Extensive cross-fostering is widely used in early-weaning units in order to standardize and improve body weight at weaning. However, young suckling piglets develop teat fidelity and repeated cross-fosterings could go against this behavior. This experiment was therefore conducted to compare the behavior and growth of 13 control and 14 fostered litters. Once every 3 d (from d 1 to 16 of lactation), all piglets were weighed and three piglets were switched between two fostered litters. Their unfostered littermates were called residents. Behavior was recorded for 2 h after weighing and(or) adoption and during one nursing period 24 h later. Fights were more frequent (P < 0.05) in treated than in control litters during and between nursings at all ages of adoption except d 1. Most fights occurred between resident and fostered piglets (P < 0.001), except at d 1. Fights during nursing were still more frequent in treated than in control litters 24 h after adoption (P < 0.02), except at d 1 and 16. More piglets had skin lacerations in treated than in control litters except at d 1 (P < 0.05), and scratches were more frequent in fostered than in resident piglets at d 1 (P = 0.07), 7, 13, and 16 (P < 0.01). At all ages except d 1, failed nursings and snaps at piglets were more frequent in fostered than in control litters (P < 0.05), most snaps being directed at adopted piglets (P < 0.001). In fostered litters, sows spent 15 to 30% less time lying on their sides at d 4, 7, 13, and 16 (P < 0.05). Finally, adopted piglets were 13% lighter than controls at weaning (P < 0.001), whereas residents were heavier than adopted piglets (P < 0.05) but lighter than controls (P = 0.1). These data demonstrate that cross-fostering done repeatedly during lactation is stressful for piglets and sows and does not improve body weight at weaning.

Do nurse sows and foster litters have impaired animal welfare? Results from a cross-sectional study in sow herds

“…However, research on the behavioural effects of cross fostering of piglets shows that moving piglets into a new litter after the first 24 h of life results in disruption and a temporary instability of the teat order amongst the piglets and in a higher likelihood of teat fights during milk let down (Robert and Martineau, 2001). Such behavioural effects may also occur when an entire litter is transferred to a nurse sow since piglets will attempt to re-establish their previous nurse order, despite the fact that udder anatomy may be different with respect to position and number of functional teats.…”

Risks associated with preweaning mortality in 855 litters on 39 commercial outdoor pig farms in England

“…Fostering older piglets may increase the risk of mortality because the established teat order is disrupted (Robert and Martineau, 2001) or because piglets are exposed to pathogens against which they are not adequately protected (McCaw, 2000).…”

“…In all farrowing systems, piglet mortality is affected by litter size (Wolf et al, 2008), fostering practice (Robert and Martineau, 2001), sow parity (Tubbs et al, 1993), disease status and treatment and vaccination regimes (Wittum et al, 1995). Provision of assistance by farm workers to new born piglets, such as drying the piglet or moving it to the teat, has also been reported to reduce preweaning piglet mortality (Andersen et al, 2009).…”

Comparison of the behaviour of piglets raised in an artificial rearing system or reared by the sow

“…Furthermore, more missed suckling episodes and a greater amount of time spent in disputes over teats were observed after crossfostering in low birth weight piglets reared in large litters composed of average and high birth weight piglets (Deen and Bilkei, 2004). Cross-fostering performed several times during lactation can be detrimental to piglets, because of more fighting at the udder, more injuries apparent on the face and body, more unsuccessful nursing episodes, and a lower body weight at weaning (Robert and Martineau, 2001). …”

“…A common method to balance litter size between sows is to use cross-fostering (Robert and Martineau, 2001;. Piglets are relocated from their biological mother to another lactating sow with fewer piglets, while taking factors into account like litter size, gender and weight of the piglets, maternal behaviour of the sow, milk production, position of teats at the udder and number of functional teats .…”