One of the major challenges in lameness management is prompt detection, especially before visible gait disturbance. This scoping review describes the potential biomarkers for lameness in dairy cows reported in the literature, their relevance in lameness diagnosis, identifying cows at risk of developing claw lesions and monitoring recovery after treatment. Using specific keywords, a comprehensive literature search was performed in three databases: PubMed, Google Scholar and ScienceDirect to retrieve relevant articles published between 2010 and 2022. A total of 31 articles fulfilling the inclusion criteria were analysed. The categories of potential markers for lameness reported in the literature included acute phase proteins (APPs), nociceptive neuropeptides, stress hormones, proteomes, inflammatory cytokines and metabolites in serum, urine and milk. Cortisol, APPs (serum amyloid A and haptoglobin) and serum, urinary and milk metabolites were the most studied biomarkers for lameness in dairy cows. While APPs, nociceptive neuropeptides and blood cortisol analyses assisted in elucidating the pain and stress experienced by lame cows during diagnosis and after treatment, evidence-based data are lacking to support their use in identifying susceptible animals. Meanwhile, metabolomic techniques revealed promising results in assessing metabolic alterations occurring before, during and after lameness onset. Several metabolites in serum, urinary and milk were reported that could be used to identify susceptible cows even before the onset of clinical signs. Nevertheless, further research is required employing metabolomic techniques to advance our knowledge of claw horn lesions and the discovery of novel biomarkers for identifying susceptible cows. The applicability of these biomarkers is challenging, particularly in the field, as they often require invasive procedures.

This research paper proposes a simple image processing technique for automatic lameness detection in dairy cows under farm conditions. Seventy-five cows were selected from a dairy farm and visually assessed for a reference/real lameness score (RLS) as they left the milking parlor, while simultaneously being video-captured. The method employed a designated walking path and video recordings processed through image analysis to derive a new computerized automatic lameness score (ALDS) based on calculated factors from back arch posture. The proposed automatic lameness detection system was calibrated using 12 cows, and the remaining 63 were used to evaluate the diagnostic characteristics of the ALDS. The agreement and correlation between ALDS and RLS were investigated. ALDS demonstrated high diagnostic accuracy with 100% sensitivity and specificity and was found to be 100% accurate with a perfect agreement (ρc = 1) and strong correlation (r = 1, P < 0.001) for lameness detection in binary scores (lame/non-lame). Moreover, the ALDS had a strong agreement (ρc = 0.885) and was highly correlated (r = 0.840; 0.796–1.000 95% confidence interval, P < 0.001) with RLS in ordinal scores (lameness severity; LS1 to LS5). Our findings suggest that the proposed method has the potential to compete with vision-based lameness detection methods in dairy cows in farm conditions.

Lameness, a disease often observed in loose-housed dairy cattle herds, affects animal welfare in general and reduces cow locomotion. As cow traffic may be affected by restricted locomotion, lameness may be a significant problem in herds with automatic milking systems (AMSs). Between January and August 2002, a field study was conducted to evaluate animal health in eight herds with an AMS. Herd sizes ranged from 60 (n = 5 herds with one automatic milking unit [AMU]) to 120 cows (n = 3 herds with two AMUs). Four visits were made, during which 40-50 cows were randomly assigned for clinical examination of body condition, cleanliness, claw length, disorders of claws and legs, lameness, pressure lesions, and disorders of udder and teats. Lameness was observed in 14% of cows, ranging from 5% to 28% between herds. Approximately 60% of cows had pressure lesions on the hock and 23% of cows had overgrown claws. Preliminary results show that overgrown claws, pressure sores with swellings, early stage of lactation, and high milk yield significantly increased the risk of lameness. Lameness significantly reduced the number of voluntary milkings per day.

This study compares various morphometric features of two strains of broilers, selected and ‘relaxed’ (ie random-bred), raised under two feeding regimes, ad-libitum-fed and restricted-fed. We consider the possible consequences of the different body shapes on the musculoskeletal system. The ad-libitum-fed selected birds reached heavier bodyweights at younger ages, had wider girths, and developed large amounts of breast muscle which probably displaced their centre of gravity cranially. At cull weight, they had shorter legs than birds in the other groups and greater thigh-muscle masses; therefore, greater forces would have to be exerted by shorter lever arms in order to move the body. The tarsometatarsi were broader, providing increased resistance to greater loads, but the bones had a lower calcium and phosphorus content, which would theoretically make them weaker. Many of these morphological changes are likely to have detrimental effects on the musculoskeletal system and therefore compromise the walking ability and welfare of the birds.

Chronic stress occurs when animals are unable to deal with a persistent stressor with species-typical responses, or when several stressors are present concurrently. Chronic stress is most frequently considered in intensive systems, but it may also be a welfare concern for extensively managed species, such as the sheep. Here we review behavioural and physiological responses of sheep to experimentally induced chronic stressors to determine relevant indicators of chronic stress. Neuroendocrine responses to chronic stress are difficult to interpret because initial responses are followed by an apparent normalisation. Thus, cortisol or catecholamines may be at or below pre-stress levels during chronic stress, but this varies with different stressors. Chronic stress can also affect reproductive function, impair body and wool growth and meat quality, reduce immune function, and is associated with greater parasite burdens in sheep. Chronic stress induces alterations in behaviour patterns, particularly activity and feeding, and circadian rhythms of behaviour. Stereotypic behaviours, however, are infrequent in sheep and may occur only in experimental conditions of social isolation. Behavioural and physiological data suggest that rough handling and sheepdogs may be sources of chronic stress for sheep. Social subordination and weaning also act as chronic stressors, leading to higher parasitism in these animals and a greater response to additional stressors. Lameness and parasitism are associated with physiological and behavioural responses indicating that these are severe forms of chronic stress in sheep. It is unclear whether environmental stressors, such as weather and food availability, induce chronic stress in sheep. Under-nutrition may, however, be a welfare concern through its impact on lamb survival. The existence of many sources of chronic stress in the management of sheep suggests that the welfare of this species requires more attention than it has currently received.

Some aspects of on-farm assessment of social behaviour and avoidance distance were investigated on 20 Austrian dairy farms. The avoidance distance of at least 75% of cows was assessed. Social behaviour of the cows was observed for one hour and the number of animals standing was recorded every 10 min. Lameness of each animal was scored, and Spearman correlations were calculated. Generally, the avoidance distance of the cows was very low. Lameness did not correlate significantly with avoidance distance. The number of agonistic interactions with body contact per cow correlated negatively with the percentage of lame animals (rs = -0.49; P = 0.029). However, this correlation was no longer found (rs = -0.22; not significant) when calculated on the basis of standing animals only. The total number of social interactions correlated highly with the number of social interactions when interactions in the feeding rack were disregarded. The present study suggests that lameness confounds the assessment of social behaviour but not that of avoidance distance of cows, and that social interactions of animals standing in the feeding racks can be disregarded without decreasing the reliability of the assessments.

Pain experienced by lame cattle is often masked by their instinctive stoicism, leading to delayed detection and treatment of lameness. This paper investigates the usefulness of posture scoring during locomotion and the evaluation of daily activity levels as indicators of pain and discomfort resulting from lameness in dairy cattle. In this study, 345 lactating cattle were observed over a seven-month winter housing period. The posture of each cow was scored twice weekly using a subjective five-point numerical rating scale. Daily activity levels were measured objectively using pedometers. The effect of lameness on behaviour was addressed. Increased posture scores were associated with the presence of foot lesions (P < 0.001) and with reduced daily activity levels (P < 0.001). In comparison to sound cows, lame cows showed lower daily activity levels (P < 0.001). These results improve understanding of pain-related behaviours in cattle, and such an approach may assist future development of welfare assessment systems.

This study tests the hypothesis that growth rate and bodyweight affect walking ability in broilers by comparing objective measurements of the spatial and temporal gait parameters of several groups of birds. Two strains of birds were used (relaxed and selected), raised on two feeding regimes (ad-libitum and restricted), and culled at the same final bodyweight (commercial cull weight of 2.4 kg). The ad-libitum-fed selected birds walked more slowly, with lower cadences, and took shorter steps. The steps were wider, and the toes were pointed outwards, resulting in a wider walking base. They kept their feet in contact with the ground for longer periods, having longer percentage stance times, shorter percentage swing times and increased double-contact times compared to the relaxed birds. These changes serve to increase stability during walking and are a likely consequence of the morphological changes in the selected broiler — in particular, the rapid growth of breast muscle moving the centre of gravity forward, and the relatively short legs compared to their bodyweight (see Corr et al, pp 145-157, this issue). This altered gait would be very inefficient and would rapidly tire the birds, and could help to explain the low level of activity seen in the modern broiler.

In Denmark and Sweden, surveys were undertaken to estimate the prevalence of leg problems in conventional broiler production. The Danish survey included 28 Ross 208 flocks, and the Swedish survey included 15 Ross 208 and 16 Cobb flocks. Leg problems included reduced walking ability (gait), tibial dyschondroplasia (TD), varus/valgus deformations (VV) and foot-pad dermatitis (FPD). Danish Ross chicks showed a significantly higher prevalence of gait score > 0, gait score > 2 and TD, but a lower prevalence of VV, than Swedish Ross chicks. Cobb chicks showed a significantly higher prevalence of gait score > 0, gait score > 2 and TD than Swedish Ross chicks, a significantly higher prevalence of VV than Danish Ross chicks, and a significantly lower prevalence of FPD than both Danish and Swedish Ross chicks. The two genotypes of Swedish chicks showed similar relationships between body weight and probability of gait score > 0, TD and VV, indicating that the difference in prevalence of these leg problems may be due to the difference in mean body weight at slaughter age. At body weights below 2300 g, Danish chicks showed a higher probability of gait score > 2 than Swedish chicks. Furthermore, at body weights below 1900 g, Danish chicks had a higher probability of TD than Swedish chicks, whereas at body weights above 2200 g they had a lower probability of TD. This indicates that the difference in prevalence of TD between Danish and Swedish chicks was due to differences in mean body weight at slaughter age as well as housing conditions. Therefore, further studies on the risk factors in relation to management and housing conditions are required.

In the UK, broiler chickens are normally slaughtered at about six weeks of age when they weigh approximately 2.2 kg; this contrasts with the growth of an ‘unimproved’ traditional strain of bird such as a White Sussex, which would weigh about 800 g at the same age. Lameness, characterised by abnormal gait, posture and impaired walking ability, can be prevalent in these rapidly growing birds and has been highlighted as a major welfare concern. It is during the later stages of rearing, when the bird is becoming heavy and may be achieving weight gains of over 50 g per day, that lameness begins to have an economic and welfare impact on the flock and to compromise the behaviour of large numbers of birds. A study was carried out to identify potential differences in the expression of genes between groups of lame and normal broiler chickens using subtraction hybridisation. The first group comprised lame birds with measurable gait abnormalities, and the second group comprised sound (not lame) birds. Both populations came from within the same flock. After extraction of mRNA and creation of cDNA, subtractive hybridisation was performed to eliminate genetic sequences common to both populations. The resultant DNA was separated and presented for sequence data analysis and comparison with a large sequence database. Some examples of the subtracted sequences detected are given, and the potential significance of these sequence differences at the individual and group level is discussed.

Bodily contact with water is a novel and aversive experience for broiler chickens, and this has been used when designing the Latency to Lie (LTL) test. The original testing procedure, in which the birds are tested in groups, involves a certain settling period, which makes the test time-consuming to carry out on commercial broiler farms. Our modifications of the LTL test for on-farm use mean that a) the birds are tested individually without visual contact with other birds; and b) the water tub is already filled with water when the birds are placed in it. The results from the LTL tests can then be compared with the scores achieved for each individual bird on the commonly used ‘gait scoring’ procedure. At 14 farms participating in a larger survey, we used three birds of each gait score from 0 to 4 (when available) for LTL testing. The time spent standing before making the first attempt to lie down was recorded. The results show a clear negative correlation (r = -0.86, P < 0.001) between time spent standing and gait score. The mean LTL values for the different gait scores were all significantly (P < 0.01) different. There was no significant difference in LTL results between flocks. The method described appears to be well suited for on-farm use. If further developed, it could become a useful tool in monitoring programmes for the ongoing efforts aiming at decreasing the levels of leg weakness in modern broiler production.

In the present study, the effect of training on inter-observer reliability was studied for a 5-category lameness scoring system used for routine on-farm surveys of welfare in dairy cattle. The inter-observer agreement between an experienced and an initially inexperienced observer was determined during an initial training phase and at specific time points in the course of data collection in 46 herds. During the training phase on three farms, inter-observer reliability increased to an acceptable level for both the 5-category gait scoring system and the distinction between lame and non-lame cows.

The 4th testing after 17 on-farm visits revealed a considerable increase in inter-observer reliability which was further improved in the course of the on-farm visits.

In conclusion, acceptable inter-observer agreement for differentiating between non-lame and lame cows was achieved after only a brief introduction. In order to obtain high inter-observer repeatability with the 5-category gait scoring system used in this study, (more) intensive training procedures are required.

As part of a larger on-farm dairy cow welfare and behaviour project, data were collected from 22 commercial dairy farms over two winters (2000-2001 and 2001-2002). A further winter of farm sampling will complete the project (2002-2003), with five types of housing and production systems being assessed: high-, medium- and low-milk-production herds with cubicle housing, high-production herds with zero grazing and cubicle housing, and medium-production herds with straw courts. All cows in one early or mid-lactation group from each farm were observed. For the current analysis, locomotion, cleanliness and body condition were scored for the group, and an audit of building quality was carried out. Analysis of the available data shows that some aspects of building design affect the welfare of dairy cows. A positive correlation was found between mean body condition score of the cows and mean locomotion score (P = 0.047). Body condition score correlated negatively with the number of cows in the group (P = 0.049). Negative correlations were found between locomotion score and the ratio of cubicles to cows (P = 0.033) and between the size of cubicles and leg cleanliness (P = 0.012). Trends were also seen in the relationships between farm type and locomotion score (P = 0.048), production level and locomotion score (P = 0.074) and cow cleanliness and cubicle size (P = 0.061). These results indicate that the quality of the housing and the management system can affect cow welfare. These measures may be useful to include in on-farm welfare assessment schemes.

Lameness is an indicator of pain and suffering, which has substantial animal welfare and economic impact on the dairy industry. Subjective locomotion scoring is unreliable for detecting mild cases of lameness in dairy herds. Undetected lameness can progress to a more serious and painful state with unfavourable prognosis. The aim of this study was to conduct an investigation on the use of a pressure plate for early detection of lameness in dairy heifers compared to a subjective visual scoring system. Seven heifers deemed sound, on the basis of a visual scoring system, were walked through a chute where a pressure plate was disguised on the floor. Claws were then inspected during trimming and revealed no lesions (n = 3) and hairy heel warts on at least one hind claw (n = 4). Peak vertical force (PVF) and right-left hind limb PVF symmetry were calculated. Sound heifers demonstrated significantly higher PVF and better right-left hind limb symmetry than those with hairy heel warts. Using a pressure plate, gait abnormalities from foot lesions that were undiagnosed using a subjective lameness scoring system, were detected. Early detection of lameness is vital to reduce dairy industry losses and to improve animal welfare.

A case study is described in which a high incidence of lameness in broiler chickens (Gallus gallus domesticus) is associated with rearing to 84 days of age; broilers are normally slaughtered at less than 50 days of age. A sample of 185 birds was scored for walking ability, and 24 birds from this group were assessed for dehydration by measuring plasma osmolality. The proportion of the group having gait abnormalities was compared with that recorded during a recent survey of Danish flocks and was found to be higher. A relationship is established between the degree of gait impairment and the level of dehydration. The degree of dehydration is related to the findings for plasma osmolality from previous research, and the results indicate that some of the birds in this case may have been deprived of access to water for periods in excess of 60 hours.

The Welfare of Farmed Animals (England) Regulations (2007) make it an offence to allow unnecessary suffering to animals, highlighting that farmers have a duty of care for their livestock. Despite this, the current global mean prevalence of lameness in sheep in England is 5%; ie ~750,000 lame adult sheep at any time. To investigate farmers’ attitudes to sanctions and rewards as drivers to reduce the prevalence of lameness in sheep, farmers’ attitudes to external inspections, acceptable prevalence of lameness and attitudes on outcomes from inspections were investigated using a self-administered questionnaire. A total of 43/102 convenience-selected English sheep farmers responded to the questionnaire. Their median flock size was 500 ewes with a geometric mean prevalence of lameness of 2.8%. Few farmers selected correct descriptions of the legislation for treatment and transport of lame sheep. Participants considered 5-7.5% prevalence of lameness acceptable and were least tolerant of farmers who rarely treated lameness and most tolerant of farmers experiencing an incident out of their control, eg disease outbreak. Participants consider sanctions and rewards would help to control lameness on sheep farms in England. Sanctions (prosecution, reduction in payment from the single [basic] payment scheme or suspension from a farm assurance scheme) were considered ‘fair’ when lameness was ≥ 10% and rewards ‘fair’ when lameness was ≤ 2%. If these farmers’ attitudes are applied to 1,300 randomly selected flocks with a mean prevalence of lameness of 3.5%, 24.6% of flocks that had ≥ 10% lameness would be sanctioned and 32.5% of flocks that had ≤ 2% lameness would be rewarded.

Leg disorders are a major cause of poor welfare in broilers. Previous studies have shown that at slaughter age at least 90% of chickens experienced some degree of gait problems and approximately 30% were seriously lame. In this study, a new and non-invasive technique was developed to automatically assess the lameness of the birds. For this purpose, video surveillance images of broilers with five different pre-defined gait scores were recorded as they walked along a test corridor. Afterwards, the image-processing algorithm was applied to detect the number of lying events (NOL) and latency to lie down (LTL) of broiler chickens. Then, the results of the algorithm were compared with visually assessed manual labelling data (reference method) and the relation between these measures and lameness was investigated. Eighty-three percent of NOL were correctly classified by the automatic monitoring system when compared to manual labelling using a data set collected from 250 broiler chickens. The results also showed a positive significant correlation between NOL and gait score and a significant negative correlation between LTL and gait-score level of broilers. Since strong correlations were found, on the one hand, between two measures and gait-score level of broiler chickens and, on the other, between the results of algorithm and manual labelling, the results suggest this automatic monitoring system may have the potential to be used as a tool for assessing lameness of broiler chickens.

Investigating variability of scores between different observers, between animals and over time aids the design of valid sampling methodologies for measuring animal welfare. Locomotion scores (0 to 5 scale) were collected: i) from 154 sows in one herd, using three to five observers each time, and scoring sows on up to ten occasions over a 19-month period; and ii) for 123 of these sows, locomotion scoring also took place prior to farrowing and at weaning. The distribution of scores was highly skewed towards low scores (0: 84.8%, 1: 9.5%, 2:4.0%, 3+: 1.7%). Sows showed moderate consistency in their scores over time and later parity sows had higher scores, but there was no effect of stage in the reproductive cycle (days pregnant, pre-farrowing, post-weaning). This suggests that infrequent visits to a farm (eg annual) might provide an accurate estimate of the extent of lameness if a representative range of parities was sampled, although a larger study of more farms would be required to investigate this. The three different types of agreement between observers (absolute differences, matching and association) were assessed as follows: i) analysis of absolute differences between observers showed that the farm manager scored lower than researchers/technicians; ii) exact matching approaches suggested fair or good agreement — agreement was poorest for mild gait abnormalities (score 1 ‘stiff’), and agreement improved if scores were combined into ‘sound’ (0-1) and ‘lame’ (2-5) categories; and iii) measures of association suggested moderate agreement. Inter-observer reliability improved over time until the 5th scoring event. To improve inter-observer agreement, observer training/practice and the use of fewer categories are recommended, and inter-observer agreement should be checked regularly.

We investigated the temporal associations between the severity of foot lesions caused by footrot (FR) and the severity of lameness in sheep. Sixty sheep from one farm were monitored for five weeks. The locomotion of each sheep was scored once each week using a validated numerical rating scale of 0-6. All feet were then examined, FR was the only foot lesion observed; the severity of FR lesions was recorded on a scale from 0 to 4. Sheep had a locomotion score > 0 on 144/298 observations. FR lesions were present on at least one foot on 83% of observations of lame sheep but also present on 27% of observations where sheep were not lame; 95% of these sheep with a lesion but not lame had FR score 1. The results from a linear mixed model with locomotion score as the outcome were that the mean (95% CI) locomotion score of 0.28 (0.02, 0.53) in sheep with no lesions increased by 0.35 (0.05, 0.65) in sheep with FR score 1 or 2 and by 1.55 (1.13, 1.96) in sheep with FR score > 2 at the time of the observation; indicating that as the severity of the lesion increased, the severity of lameness increased. One week before an FR score > 2 was clinically apparent, sheep had a locomotion score 0.81 (0.37, 1.24) higher than sheep that did not have an FR score > 2 in the subsequent week. One week after treatment with intramuscular antibacterials the locomotion score of lame sheep reduced by 1.00 (0.50, 1.49). Our results indicate a positive association between severity of FR lesions and locomotion score and indicate that some non-lame and mildly lame sheep have footrot lesions. Treatment of even those mildly lame will facilitate healing and probably reduce the spread of infection to other sheep in the same group.

Lameness is one of the most serious health and welfare problems faced by dairy cattle. The aim of this study was to assess how aware Czech farm managers were of this problem. The project was carried out on 14 Czech dairy farms. The proportion of lame cows observed (ie prevalence of moderate and severe lameness) on a farm varied between 9 and 64% while the farm managers’ estimation ranged between 0 and 20%, showing that lameness prevalence was under-perceived by the Czech farm managers. There were no correlations between the farm managers’ estimations and the observed total or severe lameness on each farm. Also, the observed prevalence of lameness did not differ between farms with managers who considered lameness to be a major problem in their herds and managers who did not, although their estimations did differ. The large variation in observed lameness prevalence between farms indicates that there is a large potential for reduction, which must start with increasing the farm managers’ awareness of dairy cow lameness.