Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/15/2008
Publication Date: 4/1/2009
Citation: Marchant Forde, J.N., Lay Jr, D.C., Mcmunn, K.A., Cheng, H., Pajor, E.A., Marchant-Forde, R.M. 2009. Postnatal piglet husbandry practices and well being: The effects of alternative techniques delivered separately.. Journal of Animal Science. 87:1479-1492.
Interpretive Summary: One to three days after being born, piglets on commercial farms undergo various routine processing procedures. Nearly all piglets will have their canine teeth clipped to prevent scratching the sow and other piglets, their tails docked to prevent tail-biting, and they will be given an injection of an iron-containing compound to prevent anemia. Male piglets will be castrated to prevent the meat being flavored by male hormones. Additionally, some piglets, depending on the farm policy, may also have notches cut out of their ears so that they can be individually identified. All of these procedures have come under scrutiny from the animal welfare lobby as they inflict a degree of pain and distress. Over recent years, alternative methods have been developed to reduce the impact of the procedure on the piglet. This study investigated the relative impact of alternative methods, when only one procedure was applied to each piglet. We found that, in general, the alternative technique that took the longest caused the greatest amount of distress. Using a grinder to grind down canine teeth instead of clippers took longer and had a higher impact on well-being. Using a hot, cauterizing clipper to dock tails instead of side cutter pliers took longer and had a higher impact on well-being as more precision was required. Delivering iron in the form of an oral paste instead of injecting, took longer and had a higher impact on well-being. Notching ears instead of inserting a numbered ear tag took longer and had a higher impact on well-being. Finally, castrating by tearing the spermatic cords took longer than cutting the spermatic cords and had a higher impact on well-being. In most cases, the technique most commonly being used on farms proved to have the lower impact on well-being. However, in the case of identification, ear tagging was shown to be better for the piglets than ear notching, which involves quite a large amount of tissue damage. Indeed, ear notching evoked piglet squeals that were nearly as intense as those associated with castration, which is known to be a considerable source of pain. Overall, our results show that when given separately, it is important for producers to be quick and accurate in order to minimize the amount of stress that piglets undergo.
Technical Abstract: Soon after birth, piglets undergo procedures that are a likely source of stress. The aim of this study was to evaluate the relative impact on stress responses of two alternative methods for performing the following processing procedures: 1) teeth resection (TR) - clip vs. grind; 2) tail-docking (TD) - cold vs. hot-clip; 3) identification (ID) - ear notch vs. tag; 4) iron administration (FE) - inject vs. oral; 5) castration (CA) - cords cut vs. torn. Eight to ten litters of eight, 2-3 day-old piglets were assigned to each procedure. Within each litter 2 piglets were assigned to 1 of 4 possible procedures: the two alternative methods, a sham procedure, and a sham procedure plus blood sampling. Blood was sampled before processing and at 45 min, 4h, 48h, 1wk, and 2wks post-procedure and assayed for cortisol and beta-endorphin. Procedures were video-taped and analyzed to evaluate the time taken to perform the procedure and the number of squeals, grunts and escape attempts. Vocalizations were also recorded digitally and analyzed to determine duration, mean and peak frequencies. Piglets were weighed before the procedure and at 24h, 48h, 1wk and 2wks afterwards. Lesions were scored on a 0 to 5 scale on ID, TD and CA pigs at 24h, 1 wk and 2wks post-procedure. TD piglets also had their tails examined for pathological changes relating to neuroma formation. For TR, grinding took about 20s longer than clipping and resulted in higher cortisol levels overall, poorer growth rates, more escape attempts and longer vocalizations (P<0.05). For TD, hot clipping took longer (P<0.05) and resulted in more, longer and higher frequency squealing (P<0.001) and more neuromas (P<0.05). For FE, oral delivery took longer and resulted in more squealing (P<0.05). For ID, notching took longer, resulted in higher lesion scores (P<0.05), more, higher frequency squealing (P<0.001), more escape attempts (P<0.01) and tended to result in higher cortisol concentrations (P<0.1). For CA, tearing took longer and resulted in more squealing and escape attempts (P<0.05). The results indicate that for each procedure, it was possible to determine the lower and higher impact technique, when those techniques were applied separately. In addition, the time required to perform procedures contributed significantly to the degree of stress experienced by the pigs and thus, when given separately, carrying out the procedure as quickly as possible, but accurately, will be least stressful for the piglet.