Docked tail length is a risk factor for bacterial arthritis in lambs

Frequency and Characterisation of Anomalies and Fractures of the Caudal Spine in Sheep with Undocked Tails

As tails are often docked within the first days of life, studies investigating tail malformations and injuries in sheep do not exist thus far. To address this gap in the literature, this research aimed to analyse the occurrence of vertebral anomalies and fractures in the tail within an undocked Merinoland sheep population. At 14 weeks of age, the caudal spines of 216 undocked Merinoland lambs was radiographically examined, and tail length and circumference were measured. Anomalies were documented and statistical correlation and model calculations were performed. The occurrence of block vertebrae was observed in 12.96% and wedged vertebrae in 8.33% of the sample. Of the animals, 59 (27.31%) exhibited at least one vertebral fracture, which were observed in the middle and caudal third of the tail. A significant correlation was found between the occurrence of fractures and tail length (r = 0.168) and number of vertebrae (r = 0.155). Conversely, the presence of block and wedged vertebrae was not significantly correlated with tail length, circumference, or number of vertebrae. Only the sex showed significant differences in the probability of axis deviation. These results emphasize the importance of breeding for short tails to avoid fractures.

How Well Does Australian Animal Welfare Policy Reflect Scientific Evidence: A Case Study Approach Based on Lamb Marking

The development and substance of animal welfare policy is subject to a range of social, cultural, economic, and scientific influences that commonly vary within and between countries. Discrepancies in policy can create confusion and mistrust among stakeholders and consumers and limit the ability to create a uniform minimum level of requirements to safeguard animal welfare, as well as create a level 'playing field' for farmers when trading with other jurisdictions. The livestock sector is receiving growing scrutiny globally for real and perceived violations of animal welfare, for example, the practice of mulesing in Australia. This article explores animal welfare legislation within Australia and how it reflects the scientific evidence surrounding routine husbandry practices in sheep, including tail docking, castration, and mulesing. While there is some variation between state and territory legislation, the most notable concern is the lack of enforceable recommendations surrounding the evidence-based use of analgesia and anaesthesia for painful husbandry procedures. The age at which these procedures are recommended to be performed is relatively consistent across Australian jurisdictions, but there is a marked difference compared to international legislation. The global context of animal welfare legislation, public perception, and producer perception of these procedures are also discussed, highlighting the difficulty of creating robust animal welfare legislation that promotes a good standard of welfare that is respected worldwide whilst being practical in an Australian setting given our unique geography and climatic conditions.

Measuring Sheep Tails: A Preliminary Study Using Length (Mm), Vulva Cover Assessment, and Number of Tail Joints

Docking sheep tails is a long-standing practice that, when done at the recommended length, reduces the risk of flystrike. The recommended length is to cover the vulva of ewes and to a similar length in males. This length is often equated to three coccygeal joints left intact, and there are many other ways the recommended length is described by researchers, industry, and government. This study compared the observer consistency and retest consistency using three different tail length measurement methods: vulva cover assessment, length (mm), and joint palpation. The tails of 51 yearling and 48 weaner Merino ewes were assessed by two observers. Length and vulva cover assessment methods provided the most reliable results, and joint palpation was the least reliable method of tail measurement. In the sample, tails that covered the vulva of yearlings and weaners measured 57.6 mm (n = 14) and 63.7 mm (n = 30) on average, respectively, and contained two coccygeal joints (more than two coccygeal vertebrae). Tails that did not cover the vulva of yearlings and weaners measured 41.3 mm (n = 36) and 52.8 mm (n = 17) on average, respectively, and had less than two coccygeal joints. The two most reliable methods enable valid comparison to the best practice recommendations.

Bedeutung der Schwanzlänge beim Schaf und Zucht auf Kurzschwänzigkeit

Eine Möglichkeit, das Kopieren von Schwänzen bei Schafen in der Zukunft zu vermeiden, stellt die Zucht auf Kurzschwänzigkeit dar. Dies erscheint vielversprechend, da die Urform der Hausschafe, der Mufflon, einen relativ kurzen schmalen Schwanz besitzt. Es kann folglich davon ausgegangen werden, dass längere Schwänze ein Resultat der Domestikation sind. Ältere Untersuchungen zur Heritabilität der Schwanzlänge beim Hausschaf konnten rasseabhängig Werte von 0,38 bis 0,77 nachweisen. Bei der Zucht auf Kurzschwänzigkeit muss jedoch darauf geachtet werden, dass keine Missbildungen der Wirbelsäule und benachbarter Strukturen auftreten. Bis in diesem Bereich ein Zuchtfortschritt erreicht ist, können durch Managementmaßnahmen die negativen Auswirkungen länger bewollter Schwänze (z. B. Myiasisbefall, Dermatitis) gemindert werden. Dazu gehören die Vermeidung von Durchfällen durch eine ausgewogene wiederkäuergerechte Fütterung, ein betriebsspezifisch angepasstes nachhaltiges Parasitenmanagementprogramm und die gezielte Schur unkupierter Schwänze.

Molecular detection and genotype characterization of Streptococcus dysgalactiae from sheep flocks with outbreaks of infectious arthritis

Outbreaks of infectious arthritis in young lambs are a growing concern for the Norwegian sheep industry. In other countries, Streptococcus dysgalactiae subspecies dysgalactiae (SDSD) is a frequent cause of such outbreaks. The objectives of this study were to investigate the causes of outbreaks of infections arthritis in Norwegian sheep flocks, and describe the sources, colonization patterns and genetic diversity of SDSD in affected and healthy sheep flocks. Almost 2000 samples from joints, animal body sites and the indoor environment were analysed by qPCR and culturing for SDSD, which was detected in 27 of 30 flocks. The proportion of positive samples was greater in outbreak flocks compared to healthy flocks. Altogether, SDSD was detected in 48 % of the samples from lambs, 27 % of the samples from ewes and 48 % of environmental samples. A relatively high proportion (67 %) of ear tag wounds were SDSD positive. These wounds may provide a port of entry for SDSD. Whole genome sequencing revealed a clonal distribution of SDSD-isolates, and identified four different multi locus sequence types (STs), among which two STs, ST454 and ST531, dominated. These STs were found in geographically distant flocks. ST454 was almost exclusively found in outbreak flocks. The current study points to skin, wounds and mucous membranes of animals as the main reservoir of SDSD in sheep flocks. However, a significantly higher proportion of SDSD-positive environmental samples in outbreak flocks compared to healthy flocks suggests that also indirect transmission may play a role.

Evaluating the Welfare of Small Ruminants: Practical Management Advice

This article discusses key welfare issues for small ruminants and gives practical management advice. Welfare assessment is vital to ensure that optimal conditions are provided. Practitioners can play a key role in identifying areas of potential welfare compromise and implement interventions. With the knowledge and careful identification of indicators of welfare, practitioners and producers can develop a management plan that can ensure proper nutrition, environment, and health to allow for natural behaviors and a positive affective state; identification of animal health and management issues; and (3) allocation of adequate resources to improve the welfare of sheep and goats.

Quantifying disease and defect carcass losses at processing to improve feedback in the lamb supply chain: an arthritis case study

Context Lamb producers are currently limited in their ability to make informed on-farm management changes with respect to disease and defects identified at processing. This is due to the limited accuracy and detail of information included in disease and defect feedback supplied by processors. Increasing transparency of the feedback can allow producers to make more informed on-farm decisions, and, subsequently, improve productivity and animal welfare. Aims Using arthritis as a case study, the aim was to develop a scoring system that estimates hot standard carcass weight (HSCW) losses due to trimming at processing, so as to improve feedback to lamb producers. Methods An observational cross-sectional study was conducted at a southern New South Wales commercial processing facility, over 6 months and in five week-long blocks, from 21 February 2019 to 5 July 2019. Carcass trim components removed due to the presence of arthritis (shank or leg) were recorded for 217 of the 42164 lamb carcasses processed. Utilising average lot HSCWs, the total proportion of HSCW lost due to arthritis trimming (TPL) was calculated for each arthritic carcass. Linear regression analysis, with a logit-transform of TPL, was fitted to the data. Key results Processing lot and trim-component category were found to be significant (P << 0.001) explanatory variables for variation in TPL. Trim-component categories that were not significantly (P > 0.05) different were combined, with final categories being assigned arthritis trim scores as follows: 1, any forequarter shank; 2, any hindquarter shank; 3, any forequarter leg; and 4, any hindquarter leg. At an over-the-hooks carcass price of AU$7.83/kg and an average HSCW of 23.13 kg, these scores were used to estimate producer revenue losses per carcass (range AU$2.95–AU$18.08). Conclusions The accuracy and detail of information provided as feedback to lamb producers can be improved. For arthritis, this can be achieved using a trim-scoring system. Implications Altering feedback to include HSCW losses for processed lots in both kilograms and dollars against the associated disease or defect will better equip producers to make cost-effective on-farm management changes and reduce the impact on the lamb supply chain.

Understanding farmers' naturalistic decision making around prophylactic antibiotic use in lambs using a grounded theory and natural language processing approach

The routine use of antibiotics for prevention of disease in neonatal lambs has been highlighted as inappropriate, yet research suggests that many farmers in the UK still carry out this practice. The aim of the study was to understand farmers' naturalistic decision-making around prophylactic antibiotic use in lambs. Data from 431 posts by 133 different users of an online discussion forum were analysed quantitatively using natural language processing and qualitatively using a grounded theory approach. Results from the qualitative analysis identified five categories that influenced farmers risk perceptions around prophylactic antibiotic use in lambs: anticipated regret, negative emotions and experiential avoidance; economic considerations; farmer identity; perception of capability; and perception of social judgement. Natural language processing analysis of the posts by the study group were compared to posts on topics unrelated to antibiotic use by control groups from the same forum to understand the underlying style and tone within the text. Analytical thinking and authenticity scores were significantly lower in the study group compared to the control groups (P < 0.01). Words relating to cognitive processes were significantly higher in the study group compared to the control groups (P < 0.01). Results of the qualitative and quantitative analysis were integrated to assess the fit of the data and enhance findings from either method alone. The key findings were the identification of reasons why farmers used antibiotics prophylactically in neonatal lambs. Farmers disassociated the use of oral antibiotics in neonatal lambs from other types of antibiotics within sheep farming. Farmers used the concept of luck and uniqueness to justify their prophylactic antibiotic use. This may explain farmers' low analytical thinking scores as this reflects a more personal style of thinking as farmers express their thoughts on antibiotic use on an individual basis. Farmers' felt that they did not have the capabilities to control neonatal disease without antibiotics during busy periods and this was exacerbated by external economic constraints. For farmers' who used antibiotics for therapeutic use, fear of social judgement was an important factor in their perceptions of risk around antibiotic use. The high frequency of negations and conjunctions suggested feelings of moral duty. As such, antibiotic use has developed into a symbol of their good farming identity which conflicted with the identity held by those who used antibiotics prophylactically. These results can be used to inform knowledge exchange around prophylactic antibiotic use in lambs to improve antibiotic stewardship in the sheep farming sector.

Knowledge and attitudes are important factors in farmers' choice of lamb tail docking length

BACKGROUND

Tail docking is common practice in the sheep industry to prevent soiling of the breech and flystrike. To ensure optimal healing after tail docking and reduce the risk of arthritis, perineal cancers and prolapses, it is recommended to dock tails equivalent to the length of the vulva. However, recent studies have found that some tails are docked too short (24-86 per cent).

METHODS

To address this issue, this study aimed to identify key drivers behind tail docking length decisions. Two focus groups, phone (n=30) and online surveys (n=21) were conducted in regional Victoria, Australia to examine farmer knowledge of and attitudes towards appropriate lamb tail length and barriers to best practice. The focus group data were analysed qualitatively, and the surveys were analysed qualitatively and quantitatively.

RESULTS

In total, 57 per cent of farmers were classed as docking tails short. Short tail docking appeared to be influenced by unawareness of the recommended length and docking at a length that shearers approve of. Other potential factors included lack of knowledge of negative health consequences associated with short tails, importance placed on dag and flystrike prevention, and impracticality of measuring where to dock.

CONCLUSION

Addressing these factors in future education and intervention programmes may improve tail docking practice and sheep welfare.

Evaluating the welfare of extensively managed sheep

The aim of this study was to identify the main on-farm welfare issues likely to be encountered in extensive sheep farming systems. Thirty-two commercial sheep farms in Victoria, Australia were involved in this study. Of the 32 farms involved, 30 were visited twice (at mid-pregnancy and weaning), and 2 farms only once (both at weaning). In total, 62 visits were conducted and 6,200 ewes (aged 2-5 years) were examined using six animal-based indicators: body condition score (BCS), fleece condition, skin lesions, tail length, dag score and lameness. In addition, the number of ewes that needed further care (such as sick or injured sheep) was recorded and reported to the farmers. Generalised linear mixed models were conducted to investigate associations between welfare outcomes and visit, ewe breed and location, with all three, and their interactions, as fixed factors. In all instances, farm was set as a random factor to account for specific variation between farms. Overall, the welfare of the ewe flocks, based on the six indicators measured, was considered good. A total of 86.9% of the ewes were in adequate BCS (2.5-3.5), 91% had good fleece condition, 69.2% had no skin lesions, 97.1% had low dag scores, and overall lameness was 4.7%. An important and prevalent risk to welfare identified across farms was short tail length; with 85.7% of ewes having tails docked shorter than the third palpable joint. While the welfare of the flock was good, ewes in need of further care were identified at all farms. There were 185 (3.0%) cases needing further care, and the extent of welfare compromise of these animals was considered significant. Main reasons for further care were moderate/severe lameness or foot-related issues, BCS ≤ 2 and active dermatophilosis or broken wool. To our knowledge, this study constitutes the largest assessment of ewes conducted in Australia, and the findings provide valuable insight into the main welfare issues likely to be encountered in extensive sheep farming enterprises. Future studies should develop practical technologies that can assist in the detection of the welfare issues identified in this study. In addition, the thresholds identified here could be used for future comparison and sheep welfare benchmarking programs to assess farm performance and measure continuous improvements.

Trimming and production losses associated with bacterial arthritis in lambs presented to an abattoir in southern Australia

Bacterial arthritis in sheep is a painful and debilitating condition that is widespread across all sheep-raising regions and climatic zones of Australia. At slaughter, bacterial arthritis in sheep causes economic losses through the condemnation of all or parts of the carcass, as specified in the Australian Standard for the Hygienic Production and Transportation of Meat and Meat Products for Human Consumption. In this study, we investigated the economic cost of arthritis in lambs presenting to an abattoir in southern Australia using a combination of the prevalence of arthritis detected during meat inspection, condemnation rates, trim weight and carcass weight, and fat measurements. Data were collected on 354 lines of lambs representing 63287 carcasses. One hundred and sixty nine consignments, or approximately one-half of the consignments, had at least one carcass with arthritis/polyarthritis detected by meat inspection personnel. Four hundred and twenty-two, or 0.7%, of the carcasses had arthritis/polyarthritis in at least one joint. When arthritis was present, on average 2.0% of the line was affected. Three carcasses with arthritis were condemned and the remainder trimmed, with an average trim weight of 0.7 kg. In addition, arthritis reduced the growth of lambs by 1.2 kg hot standard carcass weight, approximately 2.7 kg liveweight (assuming 45% dressing percentage) and reduced fat cover by 1.8 mm.

Schmerzhafte Eingriffe beim Schaf – Schwanzkupieren

Schmerzhafte Eingriffe bei Schafen werden weltweit durchgeführt und unterliegen in den einzelnen Ländern unterschiedlichen Reglementierungen. In Deutschland sind schmerzhafte Eingriffe am Tier im Tierschutzgesetz geregelt. Trotzdem wird die Frage der Indikation und Methodik des Schwanzkupierens bei Schaflämmern unter verschiedenen Haltungsbedingungen kontrovers diskutiert und bewertet, wobei häufig Unterschiede zwischen theoretischen Forderungen und Erfahrungen in der Praxis auftreten. Daher müssen Indikation und Methodik dieses schmerzhaften Prozesses neu überdacht und gegebenenfalls gesetzlich neu reglementiert werden. Als kurz- und mittelfristige Perspektive sollten Veränderungen in der Methodik, auch mit Einsatz von Schmerzmitteln, in Betracht gezogen werden. Hierfür ist allerdings die Zulassung von Schmerzmitteln für die genannte Spezies erforderlich, nicht zuletzt um die praktizierenden Tierärzte von der Umwidmungspflicht und damit Haftung für mögliche Nebenwirkungen zu befreien. Als langfristige Perspektive sind züchterische Maßnahmen unumgänglich. Zur Etablierung einer Lösung, die Tieren, Tierhaltern und Tierärzten gerecht wird, werden in diesem Beitrag die relevanten Literaturquellen präsentiert und mögliche Lösungsansätze formuliert.

Using Longitudinal Assessment on Extensively Managed Ewes to Quantify Welfare Compromise and Risks

Simple Summary

Sheep managed extensively can be exposed to several welfare challenges during the year, and the risk of some diseases can increase in warmer and wetter seasons. In this study, the welfare of Merino ewes was examined over a calendar year. The welfare of these animals, kept on a single farm with consistent management, varied substantially. Overall, the largest number of ewes experienced compromise and risk to welfare at weaning, indicating that this was the most vulnerable time. The main welfare issues identified were under and over feeding, ewe mortality, lameness, ecto-parasites (flystrike) and mastitis, all of which could be improved by modifying management practices, such as improved nutritional management and monitoring and better tail docking procedures. Future research must consider that significant variation in the on-farm welfare of ewes occurs during a calendar year, which needs to be accounted for when conducting on-farm assessments.

Abstract

This study examined variation in the welfare of extensively managed ewes and potential welfare risks. A total of 100 Merino ewes (aged 2–4 years) were individually identified and examined at three key stages: pregnancy, lactation and weaning. Eight animal-based welfare measures were used to assess welfare: flight distance, body condition score (BCS), fleece condition, skin lesions, tail length, dag score, lameness and mastitis. Data were analysed by ANOVA and McNemar’s statistics. Overall, the average BCS of the group was in agreement with industry recommendations. However, a number of animals were classified with inadequate condition (either too thin or too fat) across the three observation periods. The presence of heavy dags was greatest at mid-lactation (87%, P < 0.0001), lameness was greatest at weaning (14%, P = 0.01), clinical mastitis was 1% annually, and five ewes were lost from the study. Ewes had better health at mid-pregnancy compared to mid-lactation and weaning. The main welfare issues identified were under and over feeding, ewe mortality, lameness, ecto-parasites (flystrike) and mastitis, all of which have the potential to be reduced with improved management practices. Future welfare assessment programs must consider that significant variation in on-farm welfare will occur in extensively managed systems and this needs to be accounted for when evaluating farms.