• A tucked tail worked as a detector of tail damage in finishing pigs.
• Tail posture seemed promising as an early detector of tail biting in finishing pigs.
• Tail posture was affected by risk factors of tail damage.
The purpose of the current study was to investigate the relation between the tail posture of finishing pigs and tail damage with the aims to use tail posture as (1) a detector of tail damage, (2) an early detector of tail biting to possibly predict and prevent bleeding tail damage. Tails of each individual pig (from 112 finishing pigpens) were scored three times per week for the full study period of 10 weeks. For the first aim, tail posture was observed directly in the stable three times per week, just prior to tail scoring, and pigs with a tucked tail were related to their tail scoring. The odds of being scored with a tail wound (both bleeding and non-bleeding) increased by almost sixfold if the pig was also observed with a tucked tail on the same day. More precisely, 28% of the pigs with a tucked tail were also scored with a tail wound, whereas this was only the case for 5% of the pigs with a different tail posture. This relation between a tucked tail and tail damage was larger than previously found in weaners and suggests that a tucked tail could be used as a detector of tail damage, although with the risk of many false identifications of tail damage. For the second aim, tail posture was observed from video the last 3 days prior to bleeding tail damage for case pens (n = 20; at least one pig with a bleeding tail wound) and their matched controls (n = 20). The number of pigs with lowered tails (below the tail root) was observed by scan sampling during 6 h per day. A generally higher probability of having a lowered tail was seen in the case pens compared to the control pens, but the probability of having a lowered tail did not increase prior to bleeding tail damage. Thus, the results indicate that tail posture is a promising early detector of tail biting in finishing pigs, but observations going further back than 3 days from bleeding tail damage are needed to find out when the difference in tail posture arises. Alternatively, a less severe definition of tail damage could be used. Further, the differences found were relatively small, and thus to be able to predict pens in future risk of tail damage from changes in tail posture would probably demand the development of an automatic recording method for the number of lowered tails at pen level.
An animal‐based screening method for sufficient amount of straw to fulfil the need for exploration and manipulation
By Margit Bak Jensen and Lene Juul Pedersen, October 19, 2018
This document describes a screening method to assess if pigs are supplied with a sufficient amount of straw to fulfil their need for exploration and manipulation through collection of data on the availability of straw, pigs’ exploratory behaviour and lesion scoring.
• Providing extra enrichment as an early intervention reduced tail biting outbreaks.
• Tail damage was observed among weaner pigs with intact tails in 58 of 60 pens.
• Solitary tail damage did occur without escalating into tail biting outbreaks.
Tail biting is a serious animal welfare problem in the modern pig production. A frequently studied preventive measure is enrichment materials, and increasing levels of enrichment materials, especially litter materials, reduces the risk of tail biting. However, permanent access to litter materials, can cause blockage of the slurry system and increase production cost. The aim of the present study was, therefore, to investigate if providing extra enrichment material, when observing the first tail damage could reduce the prevalence of tail biting outbreaks. The study included 1804 weaner pigs from 7 to 30 kg distributed in 60 pens with intact tails. As basic enrichment material, pens were equipped with two wooden sticks and daily provided with approximately 400 g of fine chopped straw. From outside the pen pigs were checked for tail damages three times weekly. When the first tail damage (fresh or scabbed) was recorded, the pen was assigned to one of four treatments; chopped straw (approximately 200 g/pen) on the floor (straw), haylage in a spherical cage (haylage), hanging rope with a sweet block (rope) or no extra material (control). From first treatment day and until a tail biting outbreak, tails were scored three times weekly. A tail biting outbreak occurred when four pigs in a pen had a tail damage, irrespective of wound freshness. The experiment was designed to compare the prevalence of tail biting outbreaks in each of the extra material group with the control group. A treatment was carried out in 44 of the 60 pens: 10 pens with straw, 8 pens with haylage, 7 pens with rope and 19 control pens. The risk of a tail biting outbreak was significantly lower in pens with haylage and straw compared with control pens (P < 0.05), and there tended to be fewer tail biting outbreaks in rope-pens compared with control pens (P = 0.08). The results should, though, be interpreted with caution due to the relatively small sample size. In control pens with no intervention, a tail biting outbreak developed in 42% of the pens within two to five days after the first tail damage was observed, whereas a tail biting outbreak did not occur in 32% of the control pens. In conclusion, a regular tail inspection and the use of extra enrichment material, when the first minor tail damage occur, could be one way to reduce the prevalence of tail biting outbreaks.
Tail docking involves amputating a portion of the tail for a variety of reasons. We review the scientific evidence for the rationale for tail docking, a description of the different methods used, the pain response to the procedure and the effectiveness of pain alleviation, and, finally, the alternatives to tail docking and policy regarding the practice. We focus on the three main agricultural species that are tail docked as a management practice: pigs, sheep, and dairy cattle. Methods of tail docking include cutting with a knife or scalpel, cutting with a hot docking iron, or application of a constrictive rubber ring. All methods are commonly performed without analgesia or anaesthesia, and all likely result in some degree of pain. As with any procedure that alters the integrity of an animal, it is important to consider the rationale behind docking in order to evaluate if it is necessary. Tail docking in pigs is routinely conducted on commercial swine farms because it can reduce the incidence of tail biting, an injurious and undesirable behaviour. Both behavioural and physiological changes indicate that tail docking is painful in pigs, but until robust and consistent methods for preventing tail biting are identified, this procedure is likely to continue as a management practice. This approach is reflected in public policy about the procedure. There is both behavioural and physiological evidence that tail docking is painful for sheep; both responses are reduced when pain relief is provided. Prevention of fly strike is the primary reason given for tail docking sheep, but the scientific evidence to support this rationale is surprisingly sparse. Further research is required to justify tail docking of sheep as a routine practice. Dairy cattle are docked because this practice is thought to improve cow cleanliness and udder health, however, there is no scientific evidence supporting this rationale. Tail docking cattle results in relatively few behavioural or physiological indicators of pain, but docked cows are unable to effectively remove flies from their hind end. The practice of tail docking dairy cattle is banned, discouraged or declining in most industrialized countries except the US. The long-term pain associated with tail docking is not well understood in pigs, sheep or cattle. In cases where tail docking may be justified by demonstrated benefits for the animal (possibly in case of pigs and sheep), further research is needed to find either practical alternatives or ways to alleviate the pain associated with this procedure.
Antibiotics (AB) are used in intensive pig production systems to control infectious diseases
and they are suspected to be a major source of antibiotic resistance. Following the ban on
AB use as growth promoters in the EU, their prophylactic use in-feed is now under review.
The aim of this study was to evaluate the effect of removing prophylactic in-feed AB on pig
health and welfare indicators. Every Monday for six weeks, a subset of 70 pigs were
weaned, tagged and sorted into two groups of 35 pigs according to weight (9.2 ± 0.6 kg). AB
were removed from the diet of one group (NO, n = 6) and maintained in the other group (AB,
n = 6) for nine weeks. Ten focal pigs were chosen per group. After c. five weeks each group
was split into two pens of c.17 pigs for the following 4 weeks. Data were recorded weekly.
Skin, tail, ear, flank and limb lesions of focal pigs were scored according to severity. The
number of animals per group affected by health deviations was also recorded. The number
of fights and harmful behaviours (ear, tail bites) per group was counted during 3×5min
observations once per week. Data were analysed using mixed model equations and binomial
logistic regression. At group level, AB pigs were more likely to have tail (OR = 1.70; P =
0.05) but less likely to have ear lesions than NO pigs (OR = 0.46; P<0.05). The number of
ear bites (21.4±2.15 vs. 17.3±1.61; P<0.05) and fights (6.91±0.91 vs. 5.58±0.72; P = 0.09)
was higher in AB than in NO pigs. There was no effect of treatment on health deviations and
the frequency of these was low. Removing AB from the feed of weaner pigs had minimal
effects on health and welfare indicators.
Indirect genetic effects (IGEs) are heritable effects of an individual on phenotypic values of others, and may result from social interactions. We determined the behavioural consequences of selection for IGEs for growth (IGEg) in pigs in a G × E treatment design. Pigs (n = 480) were selected for high versus low IGEg with a contrast of 14 g average daily gain and were housed in either barren or straw-enriched pens (n = 80). High IGEg pigs showed from 8 to 23 weeks age 40 % less aggressive biting (P = 0.006), 27 % less ear biting (P = 0.03), and 40 % less biting on enrichment material (P = 0.005). High IGEg pigs had a lower tail damage score (high 2.0; low 2.2; P = 0.004), and consumed 30 % less jute sacks (P = 0.002). Selection on high IGEg reduced biting behaviours additive to the, generally much larger, effects of straw-bedding (P < 0.01), with no G × E interactions. These results show opportunities to reduce harmful biting behaviours in pigs.
By Yuzhi Li, Haifeng Zhang, Lee. Johnston and Wayne Martin 2018. Animals 2018, 8(1), 13
The objective of this study was to investigate the association between social structure and incidence of tail-biting in pigs. Pigs (n = 144, initial weight = 7.2 ± 1.57 kg, 4 weeks of age) were grouped based on their litter origin: littermates, non-littermates, and half-group of littermates. Six pens (8 pigs/pen) of each litter origin were studied for 6 weeks. Incidence of tail injury and growth performance were monitored. Behavior of pigs was video recorded for 6 h at 6 and 8 weeks of age. Video recordings were scanned at 10 min intervals to register pigs that were lying together (1) or not (0) in binary matrices. Half weight association index was used for social network construction. Social network analysis was performed using the UCINET software. Littermates had lower network density (0.119 vs. 0.174; p < 0.05), more absent social ties (20 vs. 12; p < 0.05), and fewer weak social ties (6 vs. 14, p < 0.05) than non-littermates, indicating that littermates might be less socially connected. Fifteen percent of littermates were identified as victimized pigs by tail-biting, and no victimized pigs were observed in other treatment groups. These results suggest that littermates might be less socially connected among themselves which may predispose them to development of tail-biting.
An EC meeting in Grange, Ireland (28-30 November 2017) gathered information about EU initiatives to reduce tail biting and tail docking in pigs. Presentations of the meeting (incl webinar) can be found via the CIRCABC-website.
EU legislation on the welfare of pigs (Council Directive 2008/120/EC laying down minimum standards for the protection of pigs) does not allow routine tail-docking and requires farmers to provide to their pigs “manipulable material” such as straw, hay or sawdust.
To better inform farmers how to prevent routine tail docking, the Commission developed educational materials. The two videos present success stories in achieving the goal of rearing not-tailed pigs.
A Finnish farming with an intensive system rearing piglets with intact, curly tails.
An Italian farmer proud of rearing curly tails on straw