Monthly Archives: August 2018

What can carcass-based assessments tell us about the lifetime welfare status of pigs?

What can carcass-based assessments tell us about the lifetime welfare status of pigs?
Carroll et al. 2018. Livestock Science

Highlights

• The use of carcass measures to understand lifetime pig welfare status was explored.
• Tail and skin lesions acquired in early life remain visible on the carcass.
• These lesions were not necessarily visible on the live animal in later life.
• Carcass weight was negatively associated with persistent tail injuries.
• Therefore carcass lesions and weight provide useful lifetime welfare information.

Abstract

There is increasing interest in developing abattoir-based measures of farm animal welfare. It is important to understand the extent to which these measures reflect lifetime welfare status. The study aim was to determine whether lesions acquired during different production stages remain visible on the carcass, and the degree to which carcass-based measures may reflect broader health and welfare issues. 532 animals were assessed at 7, 9 and 10 weeks of age (early life, EL), and at 15 and 20 weeks of age (later life, LL) for tail lesions (TL), skin lesions (SL) and a number of health issues (HI) including lameness and coughing. Pigs were categorised according to when individual welfare issues occurred in the production process; ‘early life’ [EL], ‘later life’ [LL], ‘whole life’ [WL], or ‘uninjured’ (U) if showing no signs of a specific welfare issue on-farm. Following slaughter, carcasses were scored for tail length, tail lesions, and skin lesions and cold carcass weights (CCW) were obtained. Generalised linear, ordinal logistic and binary logistic fixed model procedures were carried out to examine the ability of TL, SL and HI lifetime categories to predict carcass traits. Pigs with TL in EL, LL and WL had higher carcass tail lesion scores than U pigs (P < 0.001). Pigs with TL in LL (P < 0.05) and WL (P < 0.001), but not in EL (P > 0.05), also had shorter tails at slaughter than U pigs. In relation to TL scores, U pigs also had a higher cold carcass weight compared to LL and WL (P < 0.001), but not EL pigs (P > 0.05). Pigs with SL in EL, LL and WL had higher healed skin lesion scores on the carcass than U pigs (P < 0.001). Health issues recorded during lifetime were not reflected in carcass measures used (P > 0.05). The current study shows that tail lesions and skin lesions, acquired at least 10 weeks before slaughter, remain evident on the carcass and consequently, may be useful as tools to assist in determining the lifetime welfare status of pigs. Low CCW was associated with tail lesions, supporting previous research suggesting that tail lesions have a negative impact on growth performance in pigs.

Early intervention with enrichment can prevent tail biting outbreaks in weaner pigs

Early intervention with enrichment can prevent tail biting outbreaks in weaner pigs
Lahrmann et al. 2018. Livestock Science.

Highlights

• 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.

Abstract

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 amputation causes acute and sustained changes in peripheral somatosensory nerve function involving inflammatory and neuropathic pain pathways

Oral presentation

 Recent Advances in Animal Welfare Science (VI),

UFAW Animal Welfare Conference, Centre for Life, Newcastle, UK 28th June 2018

Coexpression analysis of dorsal root ganglia from tail amputated pigs at different ages reveals long-term transcriptional signatures associated with wound healing and inflammation, and neuropathic pain pathways

DA Sandercock1, JE Coe1, MW Barnett2, TC Freeman2, P Di Giminiani3 and SA Edwards3

1 Animal and Veterinary Science Research Group, SRUC, Edinburgh UK,

2 The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh UK

3 School of Agriculture, Food and Rural Development, Newcastle University, Newcastle-upon-Tyne, UK

 Concerns exist that docking and biting injuries may be a cause of long term pain in the remaining tail stump during the pig’s lifetime. The potential for long-term pain has been linked to sustained cellular and molecular changes in peripheral sensory neuronal activity. The aim of this study was to conduct a transcriptome analysis of caudal dorsal root ganglia (DRG) gene expression profiles from pigs subjected to tail amputation, in particular examining genes known to be associated with inflammation and neuropathic pain. Microarray analysis was performed on caudal DRG from sham (control) and tail amputated pigs 1, 8 and 16 weeks after tail treatment at either 3 days (neonate) or 63 days (juvenile). Tail amputation injury induced highly significant gene expression changes (both up and down) compared to sham-treated intact controls at both ages (518-2,794 genes, FDR < 0.05) that were still evident 16 weeks after tail amputation. Network correlation analysis using the Markov clustering (MCL) algorithm to define expression modules revealed two highly correlated (PCT r2 = ≥0.75), interrelated transcript expression clusters related to (A) neuronal function (759 genes) and (B) wound healing (273 genes). In cluster A, gene ontology (GO) and pathway enrichment analysis identified genes with significant GO terms for voltage- and ligand-gated ion channel activity linked to regulation of membrane potentials, neurotransmitter levels and synaptic signalling. In cluster B significant gene expression was associated with receptor binding, protein transcription activity and regulation, linked to processes such as response to wounding, regulation of response to wounding, inflammatory response and activation of immune response. Cross-reference against an integrated database of known genes involved in the regulation of inflammatory and neuropathic pain revealed 124 and 61 pain–associated genes in clusters A and B, respectively. Key functional families of ion channels and receptors were significantly down-regulated in cluster A, in particular voltage-gated potassium channels and GABA receptors which are linked to increased neuronal excitability. Up-regulated functional gene families in cluster B were mostly linked to inflammation, macrophage activity, neurohormone and opioid peptide activity. DRG gene expression profiles appear to be linked to sustained tissue inflammation and remodelling (ca. 4 months) and pain perception modulation consistent with adaptive, compensatory responses to injury induced increases in peripheral sensory neuron excitability in the injured tail stump. Tail amputation causes acute and sustained changes in peripheral somatosensory nerve function involving inflammatory and neuropathic pain pathways which have implications for pig welfare.