Which is the most preventive measure against tail damage in finisher pigs: tail docking, straw provision or lowered stocking density?

Abstract

One challenge of intensive pig production is tail damage caused by tail biting, and farmers often decrease the prevalence of tail damage through tail docking. However, tail docking is not an optimal preventive measure against tail damage and thus, it would be preferable to replace it. The aim of the current study was to investigate the relative effect of three possible preventive measures against tail damage. The study included 112 pens with 1624 finisher pigs divided between four batches. Pens were randomly assigned to one level of each of three treatments: (1) tail-docked (n=60 pens) v. undocked (n=52 pens), (2) 150 g of straw provided per pig per day on the solid floor (n=56 pens) v. no straw provided (n=56 pens), (3) stocking density of 1.21 m2/pig (11 pig/pen; n=56 pens) v. 0.73 m2/pig (18 pigs/pen; n=56 pens). Tail damage was recorded three times per week throughout the finisher period by scoring the tail of each individual pig. A pen was recorded as a tail damage pen and no longer included in the study if at least one pig in a pen had a bleeding tail wound; thus, only the first incidence of tail damage on pen level was recorded. Data were analysed by a Cox regression for survival analysis assuming proportional hazards. Results are presented as hazards, and a higher hazard means that a pen has a higher risk of tail damage and of it happening earlier in the finisher period. Pens with undocked pigs had a 4.32-fold higher hazard of tail damage compared with pens with docked pigs (P<0.001). Pens with no straw provided had a 2.22-fold higher hazard of tail damage compared with pens with straw provided (P<0.01). No interactions was seen between the treatments, but the effect of tail docking was higher than the effect of straw provision (P<0.001). Stocking density did not have a significant effect on the hazard of tail damage (hazard rate ratios (HRR)=1.67; P=0.064). However, a combination of straw provision and lowered stocking density showed a similar hazard of tail damage as seen with only tail docking (HRR=1.58; P=0.39). In conclusion, tail docking and straw provision were preventive measures against tail damage, and tail docking reduced the risk more than straw provision. A combination of other preventive measures is necessary to reduce the risk of tail damage in undocked pigs to the same level as in docked pigs.

Enrichment devices for undocked heavy pigs: effects on animal welfare, blood parameters and production traits

“…However, under our experimental conditions, other factors may have helped preventing tail lesions, such as high space allowance, low number of pigs per pen, presence of environmental enrichments and stability of the groups. For example, Di Martino et al (2015) observed increased tail lesions when undocked pigs were kept under challenging conditions (high stocking density on fully slatted floors) even if the pens were enriched with straw racks suggesting a possible major role played by space allowance, or at least by a complex combination of these two factors (Larsen et al 2017).…”

Tear staining in finisher pigs and its relation to age, growth, sex and potential pen level stressors

“…The design and dimensions of the pens can be seen in Figure 1. As part of a larger study design (Larsen et al, 2018) and to test whether TS in pigs depends on different potential environmental pen level stressors, the pens were randomly divided within each batch between one level of each of three factors in a 2 × 2 × 2 factorial design: 1) TAIL: pigs with undocked (n=36) or docked tails (n=44), (2) STRAW: not provided with straw (n=40) or provided with 150 g of straw per pig per day on the solid floor (n=40), (3) STOCK: stocking density of 0.73 m 2 /pig (n=40, 18 pigs per pen, high) or 1.21 m 2 /pig (n=40, 11 pigs per pen, low). Fewer pens with undocked pigs compared to pens with docked pigs were included due to many of the undocked pigs arriving from a private herd shortly after weaning with bleeding tails in batch 2 and thus not included in the study.…”

“…Thus, it could also be expected that pens with straw provided in the current study would have a lower degree of TS. Perhaps the variation in the induced stressors was not large enough relative to the overall stress level in the pens to show an effect on TS, although they did increase the risk of tail damage (Larsen et al, 2018). On the other hand, both provision of straw and a higher stocking density may affect the dirtiness of the pen and pigs, especially towards the end of the finisher period (Larsen et al, 2017).…”

How do stocking density and straw provision affect fouling in conventionally housed slaughter pigs?

“…Also, temperature measurements of the strawbedded area might also prove effective in predicting events of fouling, which has already been shown for temperature measurements at other locations of the pen (Jensen and Kristensen, 2016). Straw has been shown to have other positive effects for slaughter pigs such as reducing the risk of tail biting (Van de Weerd et al, 2005;Scollo et al, 2013;Larsen et al, 2017a) and gastric ulceration (Di Martino et al, 2013;Herskin et al, 2016;Jensen et al, 2017), improving growth rate (Pedersen et al, 2015) and increasing the expression of species-specific behaviour such as exploration (Jensen et al, 2015). Thus, it is desirable to be able to provide straw or enrichment with similar properties without increasing the risk of fouling, and, according to our study, provision of straw was not a major risk factor.…”

“…This study uses the same animals as Larsen et al (2017a), and further details about the experimental setup can be found there.…”