Effect of video angle on detection of induced front limb lameness in horses.

BACKGROUND: Lameness examinations are commonly performed in equine medicine. Advancements in digital technology have increased the use of video recordings for lameness assessment, however, standardization of ideal video angle is not available yielding videos of poor diagnostic quality. The objective of this study was to evaluate the effect of video angle on the subjective assessment of front limb lameness. A randomized, blinded, crossover study was performed. Six horses with and without mechanically induced forelimb solar pain were recorded using 9 video angles including horses trotting directly away and towards the video camera, horses trotting away and towards a video camera placed to the left and right side of midline, and horses trotting in a circle with the video camera placed on the inside and outside of the circle. Videos were randomized and assessed by three expert equine veterinarians using a 0-5 point scoring system. Objective lameness parameters were collected using a body-mounted inertial sensor system (Lameness Locator®, Equinosis LLC). Interobserver agreement for subjective lameness scores and ease of grading scores were determined. RESULTS: Induction of lameness was successful in all horses. There was excellent agreement between objective lameness parameters and subjective lameness scores (AUC of the ROC = 0.87). For horses in the "lame" trials, interobserver agreement was moderate for video angle 2 when degree of lameness was considered and perfect for video angle 2 and 9 when lameness was considered as a binary outcome. All other angles had no to fair agreement. For horses in the "sound" trials, interobserver agreement was perfect for video angle 5. All other video angles had slight to moderate agreement. CONCLUSIONS: When video assessment of forelimb lameness is required, a video of the horse trotting directly towards the video camera at a minimum is recommended. Other video angles may provide supportive information regarding lameness characteristics.

Digital dermatitis in Swedish dairy herds assessed by ELISA targeting Treponema phagedenis in bulk tank milk.

BACKGROUND: Digital dermatitis (DD) is a contagious hoof infection affecting cattle worldwide. The disease causes lameness and a reduction in animal welfare, which ultimately leads to major decreases in milk production in dairy cattle. The disease is most likely of polymicrobial origin with Treponema phagedenis and other Treponema spp. playing a key role; however, the etiology is not fully understood. Diagnosis of the disease is based on visual assessment of the feet by trained hoof-trimmers and veterinarians, as a more reliable diagnostic method is lacking. The aim of this study was to evaluate the use of an enzyme-linked immunosorbent assay (ELISA) on bulk tank milk samples testing for the presence of T. phagedenis antibodies as a proxy to assess herd prevalence of DD in Swedish dairy cattle herds. RESULTS: Bulk tank milk samples were collected in 2013 from 612 dairy herds spread across Sweden. A nationwide DD apparent prevalence of 11.9% (8.1-14.4% CI95%) was found, with the highest proportion of test-positive herds in the South Swedish regions (31.3%; 19.9-42.4% CI95%). CONCLUSIONS: This study reveals an underestimation of DD prevalence based on test results compared to hoof trimming data, highlighting the critical need for a reliable and accurate diagnostic method. Such a method is essential for disease monitoring and the development of effective control strategies. The novelty of ELISA-based diagnostic methods for DD, coupled with the disease's polymicrobial origin, suggests an avenue for improvement. Developing an expanded ELISA, incorporating antigens from various bacterial species implicated in the disease, could enhance diagnostic accuracy. The significance of this study is underscored by the extensive analysis of a substantial sample size (612). Notably, this investigation stands as the largest assessment to date, evaluating the application of ELISA on bulk tank milk for DD diagnosis at the herd level.

Farm-level risk factors and treatment protocols for lameness in New Zealand dairy cattle.

AIMS: To identify farm-level risk factors for dairy cow lameness, and to describe lameness treatment protocols used on New Zealand dairy farms. METHODS: One hundred and nineteen farms from eight veterinary clinics within the major dairying regions of New Zealand were randomly enrolled into a cross-sectional lameness prevalence study. Each farmer completed a questionnaire on lameness risk factors and lameness treatment and management. Trained observers lameness scored cattle on two occasions, between October-December (spring, coinciding with peak lactation for most farms) and between January-March (summer, late lactation for most farms). A four-point (0-3) scoring system was used to assess lameness, with animals with a lameness score (LS) ≥2 defined as lame. At each visit, all lactating animals were scored including animals that had previously been identified lame by the farmer. Associations between the farmer-reported risk factors and lameness were determined using mixed logistic regression models in a Bayesian framework, with farm and score event as random effects. RESULTS: A lameness prevalence of 3.5% (2,113/59,631) was reported at the first LS event, and 3.3% (1,861/55,929) at the second LS event. There was a median prevalence of 2.8% (min 0, max 17.0%) from the 119 farms. Most farmers (90/117; 77%) relied on informal identification by farm staff to identify lame animals. On 65% (75/116) of farms, there was no external provider of lame cow treatments, with the farmer carrying out all lame cow treatments. Most farmers had no formal training (69/112; 62%). Animals from farms that used concrete stand-off pads during periods of inclement weather had 1.45 times the odds of lameness compared to animals on farms that did not use concrete stand-off pads (95% equal-tailed credible interval 1.07-1.88). Animals from farms that reported peak lameness incidence from January to June or all year-round, had 0.64 times odds of lameness compared to animals from farms that reported peak lameness incidence from July to December (95% equal-tailed credible interval 0.47-0.88). CONCLUSIONS: Lameness prevalence was low amongst the enrolled farms. Use of concrete stand-off pads and timing of peak lameness incidence were associated with odds of lameness. CLINICAL RELEVANCE: Veterinarians should be encouraging farmers to have formal lameness identification protocols and lameness management plans in place. There is ample opportunity to provide training to farmers for lame cow treatment. Management of cows on stand-off pads should consider the likely impact on lameness.

Pharmacokinetics of intraarticular liposomal amphotericin B in goats (Capra aegagrus hircus).

Lameness is a significant welfare concern in goats. Amphotericin B is used via intraarticular (IA) administration in models to study experimentally induced lameness in large animals. The main objective of this study was to estimate plasma pharmacokinetic (PK) parameters for amphotericin B in goats after a single IA administration. Liposomal amphotericin B was administered to ten Kiko-cross goats at a dose of 10 mg total (range: 0.34-0.51 mg/kg) via IA administration into the right hind lateral distal interphalangeal joint. Plasma samples were collected over 96 h. Amphotericin B concentrations were measured via liquid chromatography/mass spectrometry (LC-MS/MS). A non-compartmental analysis was used to derive PK parameters. Following single IA administration, maximum plasma concentration was estimated at 54.6 ± 16.5 ng/mL, and time to maximum concentration ranged from 6 to 12 h. Elimination half-life was estimated at 30.9 ± 16.5 h, and mean residence time was 45.1 ± 10.4 h. The volume of distribution after IA administration was 13.3 ± 9.4 L/kg. The area under the curve was 1481 ± 761 h*ng/mL. The achieved maximum concentration was less than the observed concentrations for other species and routes of administration. Further research is needed into the pharmacodynamics of IA liposomal amphotericin B in goats to determine specific research strategies.

Epidemiology of Digital Dermatitis in Western Canadian Feedlot Cattle.

Digital dermatitis (DD) is an emerging disease in feedlot cattle. Our objective was to identify animal- and feedlot-level risk factors for DD by analyzing individual animal health records (n = 1,209,883) and feedlot-level records from western Canadian feedlots (n = 28) between 2014 and 2018, inclusive. The risk of a DD diagnosis was higher (incidence rate ratio (IRR) = 2.08, 95% CI 1.52 to 2.86) in cattle sourced from confined background operations (CB) versus cattle sourced from auction markets (AM). Conversely, ranch direct (RD) cattle were (IRR = 0.02, 95% CI 0.04 to 0.30) lower risk than AM cattle of being diagnosed with DD. The risk of being diagnosed with DD was higher in females than in males. The magnitude of the risk in females over males was influenced by annual DD incidence in low morbidity years (2014, 2017, and 2018) (IRR = 2.02, 95% CI 1.27 to 3.19), medium morbidity years (2016) (IRR = 2.95, 95% CI 1.64 to 5.33), and high morbidity years (2015) (IRR = 5.41, 95% CI 3.27 to 8.95). At the feedlot-level, the risk of a diagnosis of DD was lower in small capacity (SCF) versus large capacity feedlots (LCF) (IRR = 0.24, 95% CI 0.05 to 0.76). Future research should focus on identifying factors that may propagate disease transmission between cattle of different sexes and from different acquisition sources.

Correlation of lesion severity with bacterial changes in Treponeme-Associated Hoof Disease from free-roaming wild elk (Cervus canadensis).

BACKGROUND: Treponeme-Associated Hoof Disease (TAHD) is a polybacterial, multifactorial disease affecting free-ranging wild elk (Cervus canadensis) in the Pacific Northwest. Previous studies have indicated a bacterial etiology similar to digital dermatitis in livestock, including isolation of Treponema species from lesions. The lesions appear to progress rapidly from ulcerative areas in the interdigital space or along the coronary band to severe, ulcerative, necrotic, proliferative lesions under-running the hoof wall, perforating the sole, and contributing to hoof elongation, deformity, and overgrowth. Eventually the lesions undermine the laminal structure leading to sloughing of the hoof horn capsule. The objective of this study was to characterize the bacterial communities associated with hoof lesions, which were categorized into 5 stages or disease grade severities, with 0 being unaffected tissue and 4 being sloughed hoof capsule. We also wanted to determine if the etiology of TAHD through morphological changes was dominated by Treponema, as observed in hoof diseases in livestock. RESULTS: The bacterial 16S rRNA gene was sequenced from 66 hoof skin biopsy samples representing 5 lesion grades from samples collected by Washington Department of Fish and Wildlife as part of a voluntary hunter program. Analysis of the relative abundance of bacterial sequences showed that lesions were dominated by members of the bacterial phyla Proteobacteria, Firmicutes, Spirochaetes, Bacteroidetes and Actinobacteria. In lesion samples, members of the genus Treponema, Porphyromonas, and Mycoplasma increased with lesion severity. Association analysis indicated frequent identification of Treponema with Porphyromonas, Bacteroides and other anaerobic Gram-positive cocci. CONCLUSIONS: The bacterial 16S rRNA gene sequencing confirmed the presence of Treponema species at all stages of TAHD lesions, treponeme specie-specific PCR and histopathology, indicating that the morphological changes are a continual progression of disease severity with similar bacterial communities. Association and abundance of these other pathogenic genera within lesions may mean synergistic role with Treponema in hoof disease pathogenesis. Characterizing bacteria involved in lesion development, and their persistence during disease progression, provides evidence for science-based management decisions in TAHD infected elk populations.

Mobility, functionality and functional mobility: A review and application for canine veterinary patients.

Mobility is an essential aspect of a dog's daily life. It is defined as the ability to move freely and easily and deviations from an animals' normal mobility capabilities are often an indicator of disease, injury or pain. When a dog's mobility is compromised, often functionality (ability to perform activities of daily living; ADL), is also impeded, which can diminish an animal's quality of life. Given this, it is necessary to understand the extent to which conditions impact a dog's physiological ability to freely move around their environment to carry out ADL, a concept termed functional mobility. In contrast to human medicine, validated measures of canine functional mobility are currently limited. The aim of this review is to summarise the extent to which canine mobility and functionality are associated with various diseases and how mobility and functional mobility are currently assessed within veterinary medicine. Future work should focus on developing a standardised method of assessing functional mobility in dogs, which can contextualise how a wide range of conditions impact a dog's daily life. However, for a true functional mobility assessment to be developed, a greater understanding of what activities dogs do on a daily basis and movements underpinning these activities must first be established.

Objective movement asymmetry in horses is comparable between markerless technology and sensor-based systems.

BACKGROUND: A markerless artificial intelligence (AI) system for lameness detection has recently become available but has not been extensively compared with commonly used inertial measurement unit (IMU) systems for detecting asymmetry under field conditions. OBJECTIVE: Comparison of classification of asymmetric limbs under field conditions and comparison of normalised asymmetry data using a markerless AI system (SleipAI; recorded on a tripod mounted iPhone 14pro [SL]); the Equinosis Q Lameness Locator (LL); the EquiMoves (EM); and subjective evaluation (SE). STUDY DESIGN: Descriptive clinical study. METHODS: Straight line trot data were collected from 52 client-owned horses in regular training. Limbs were categorised as symmetric or asymmetric. Number of analysed strides were compared with Wilcoxon's each pairs test. Inter-rater reliability in classification of asymmetric limbs was assessed with Light's Kappa. Bland Altman analysis of normalised asymmetry data was performed. RESULTS: Data from 41 horses were included. Most horses showed mild asymmetry. The EM analysed significantly more strides than the other systems, both for forelimbs and for hindlimbs (53 ± 11 strides for both, respectively; p < 0.006). The LL analysed significantly more hindlimbs strides (45 ± 13) than the SL (27 ± 6; p < 0.001). Moderate inter-rater agreement for asymmetry classification was found between systems (k = 0.59 forelimbs; 0.44 hindlimbs); agreement decreased when including the SE. For the normalised asymmetry data, the strongest agreement was found between the two IMU systems. MAIN LIMITATIONS: Horses were assessed during straight-line trot only. CONCLUSIONS: The objective systems were comparable in classification of asymmetric limbs under field conditions when using defined asymmetry thresholds. Discrepancies stemmed largely from the imposed thresholds (i.e., systems largely identified same-side asymmetry). Overall, the strongest agreement was found between LL and EM. The SL analysed significantly fewer hindlimb strides than the LL and EM which could represent a limitation of the Sleip AI.

Comparative efficacy of stannous fluoride and copper sulfate footbath solutions for the treatment and prevention of digital dermatitis in lactating dairy cows.

The objective of this study was to determine whether a novel footbath solution containing stannous fluoride (SnF2) was superior to 5% copper sulfate solution for the treatment and prevention of digital dermatitis (DD) in dairy cattle. Study 1 was conducted over 4 weeks in Missouri and involved 34 lactating Holstein-Friesian cows with hind feet DD lesions. Cows in group SF walked through a footbath containing a proprietary formulation of SnF2 once weekly, whereas cows in group CS walked through a 5% CuSO4 footbath once daily for 5 d each week. Study 2 was conducted over 8 weeks in California and involved 40 lactating Holstein-Friesian cows with hind feet DD lesions. Cows in group SF walked through a SnF2 footbath for 3 consecutive days then once a week for the following 7 weeks. Cows in group CS walked through a 5% CuSO4 footbath 3 times each week for 8 weeks. Data collection included lesion type, lesion area, locomotion score, and pain score. Digital dermatitis was actively transmitted in study 1, and lesion area and locomotion scores were lower in group SF than group CS. In contrast, DD was not actively transmitted in study 2, and lesion area and locomotion scores were similar in groups SF and CS. Stannous fluoride delayed the development of active DD lesions in study 1 compared with copper sulfate, with a lower relative risk (0.57, P < 0.001) of a hind foot developing an active DD lesion over 28 d. However, SnF2 decreased the rate that active DD lesions transitioned to M3, M4, or M0 lesions compared with 5% copper sulfate in both studies, with the relative risk of a hind foot with an active DD lesion transitioning to M3, M4, or M0 in group SF being slightly lower in study 1 (0.83, P = 0.042) and study 2 (0.90, P = 0.020) than group CS. Our findings demonstrated that walking cows through a stannous fluoride footbath once per week in a herd undergoing active transmission of infection was more effective in preventing active DD lesions, but less effective in treating active DD lesions, than walking cows through a copper sulfate footbath 4 times per week. The novel SnF2 footbath solution shows promise for controlling DD in dairy herds that want an alternative footbath solution to CuSO4 and are interested in limiting the environmental accumulation of copper.

Musculoskeletal examination of the forelimb of the horse.

OBJECTIVE: The intention of this tutorial video is to illustrate the methods of examining the forelimb and neck of a horse in order to identify abnormalities that may be associated with lameness or disease. ANIMAL: A 16-year-old quarter horse gelding was used for examination. METHODS: The horse was examined for abnormalities by means of physical examination. RESULTS: The examination of the forelimb and neck of the horse was successfully completed. CLINICAL RELEVANCE: This examination technique is required to identify abnormalities in the equine forelimb and can be utilized during a lameness examination.

Digital dermatitis-associated Treponema species detection and quantification in migratory tundra caribou (Rangifer tarandus).

Treponema spp. are associated with infectious lameness in livestock and wild ruminants. While extensive research has been conducted on cattle, investigations in wild ruminants are scarce. Hoof disease is common in caribou populations (Rangifer tarandus), but investigations are limited due to the remoteness of the Arctic. Our study aimed to assess the presence of Treponema spp. associated with bovine digital dermatitis in caribou. DNA was extracted from coronary band tissues from forty-eight caribou without visible hoof lesions and analyzed using two PCR methods (qPCR and nPCR). Treponema spp. were detected in low copy numbers/mg of tissue (3.6 to 6.6 × 101). T. phagedenis was the most prevalent and abundant species in 58% of samples by qPCR, followed by T. medium (44%), and T. pedis (10%). The qPCR and nPCR agreement ranged between 65% and 75% (Cohen's kappa 0.22-0.51). Sanger sequencing of thirteen nPCR products confirmed that treponemes in caribou are remarkably similar to those found in domestic ruminants and wild elk. Our study highlights the colonization of treponemes in healthy hooves of a wild ruminant in the Arctic, where there is no presence of livestock, and expands knowledge on the host range and distribution of treponemes. These findings also emphasize the need for further research into the multifactorial nature of treponema-associated hoof diseases and the putative role of treponemes in infectious lameness affecting caribou.

Exploring the impact of high-energy diets on cattle: insights into subacute rumen acidosis, insulin resistance and hoof health.

Cattle lameness remains a significant concern, causing economic losses and compromising animal welfare. Claw horn lesions have been identified as a major cause of lameness in dairy cows but its correlation with high-energy diet and ruminal acidosis remains unclear. Hence, the primary objective of this study was to assess the effects of a high starch and a conventional diet on the rumen environment, acute phase proteins, and metabolic alterations, with a particular focus on insulin resistance and the consequent implications for the histology of the hooves in Holstein steers. Sixteen animals were divided into the high-starch (HS; 37% starch) and conventional (CON; 16.8% starch) groups. Glucose tolerance tests (GTT), blood, rumen fluid analysis, and histological evaluations of the hoof tissue were conducted over a 102-d experimental period. The HS group showed a lower ruminal pH than the CON group, and with values indicating subacute ruminal acidosis (SARA). The plasma glucose and IGF-1 concentrations were higher in the HS group, suggesting an anabolic state. Both groups exhibited an increase in the insulin area under the curve (AUC) after the GTT on d 102. Histological analysis of the hooves showed a reduction in the length and width of the epidermal lamella in both groups. There was a significant negative correlation between the insulin AUC and the length and width of the epidermal lamella. Since both groups were similarly affected, the hypothesis that histological alterations were caused by the experimental diets still needs confirmation. Additionally, the development of SARA was not essential for the observed histological changes in the hoof. Further studies are warranted to thoroughly investigate the role of insulin and IGF-1 imbalances in claw health.

Body conformation traits in early-lactation associated with clinical mastitis and lameness in lactating Chinese holstein cows.

BACKGROUND: Comprehending the correlation between body conformation traits of cows at the early stages of lactation and prevalent lactation diseases might facilitate the execution of selection and feeding strategies that prioritize cow health. This study aimed to evaluate the impact of body conformation traits on the incidence of clinical mastitis and lameness in Chinese Holstein cows. From a pasture herd of 1472 early lactating Chinese Holstein cows, we evaluated 20 body conformation traits. During lactation, this pasture herd was visited weekly to gather clinical mastitis and lameness data. A nine-point scale was used to determine the conformation traits of cows to clarify their linear characters, including frame capacity, rump (RU), feet and leg (FL), mammary system (MS), and dairy character. A longitudinal binary disease (0 = healthy; 1 = diseased) data structure was created by allocating disease records to adjacent official test dates. The impact of body conformation traits on the risk of developing diseases (clinical mastitis and lameness) was analyzed using the logistic regression models. RESULTS: Compared to cows with low total scores (75-79 points), those with high total scores (80-85 points) of body conformation traits had a significantly lower risk of mastitis (P < 0.001). The disease status (0 or 1: binary variable) of clinical mastitis in lactating cows was significantly impacted negatively by age (P < 0.05). The fore udder attachment (FUA), angularity, rear attachment height (RAH), and rear teat placement (RTP) were all significantly associated with clinical mastitis during lactation (P < 0.05). The rear leg-rear view (RLRV) was significantly correlated with correlated considerably (P < 0.05) with lameness during lactation. An ideal score of four points on the lameness risk dimension of the RLRV may indicate a low risk of lameness. Since the risk of mastitis decreased as this trait score increased, the RTP may be an ideal marker for mastitis risk. CONCLUSIONS: According to the study, clinical mastitis and lameness risks in cows can be estimated using their body conformation traits. Cows with more centrally located rear teats have a lower risk of mastitis. These results may help dairy farmers identify cows at high risk of disease early in lactation and aid in breeding for disease resistance in cows.

Bacteriophages for Controlling Staphylococcus spp. Pathogens on Dairy Cattle Farms: In Vitro Assessment.

Pathogenic Staphylococcus spp. strains are significant agents involved in mastitis and in skin and limb infections in dairy cattle. The aim of this study was to assess the antibacterial effectiveness of bacteriophages isolated from dairy cattle housing as potential tools for maintaining environmental homeostasis. The research will contribute to the use of phages as alternatives to antibiotics. The material was 56 samples obtained from dairy cows with signs of limb and hoof injuries. Staphylococcus species were identified by phenotypic, MALDI-TOF MS and PCR methods. Antibiotic resistance was determined by the disc diffusion method. Phages were isolated from cattle housing systems. Phage activity (plaque forming units, PFU/mL) was determined on double-layer agar plates. Morphology was examined using TEM microscopy, and molecular characteristics were determined with PCR. Among 52 strains of Staphylococcus spp., 16 were used as hosts for bacteriophages. Nearly all isolates (94%, 15/16) showed resistance to neomycin, and 87% were resistant to spectinomycin. Cefuroxime and vancomycin were the most effective antibiotics. On the basis of their morphology, bacteriophages were identified as class Caudoviricetes, formerly Caudovirales, families Myoviridae-like (6), and Siphoviridae-like (9). Three bacteriophages of the family Myoviridae-like, with the broadest spectrum of activity, were used for further analysis. This study showed a wide spectrum of activity against the Staphylococcus spp. strains tested. The positive results indicate that bacteriophages can be used to improve the welfare of cattle.

Locomotion Score and Postpartum Conception in Jersey Cows Raised under Hot-Humid Tropical Conditions: A Prospective Study.

Reproductive physiology is one of the first systems which is altered when an animal suffers from an imbalance. This is crucial in tropical dairy farming, where maintaining homeostasis and production is particularly demanding. Lameness is a disorder commonly identified by impaired walking, but its early diagnosis could reduce the negative repercussions on production, welfare, and postpartum conception. To evaluate the effect of lameness on postpartum conception, a prospective observational cohort study with a cross-sectional design was developed. Fifty-two Jersey milking cows raised under hot-humid tropical conditions were scored using a five-point locomotion scoring (LS) system (1-non-lame, 2-slightly lame, 3-moderately lame, 4-lame, and 5-severely lame), considering scores ≥ 3 to indicate clinical lameness. Inseminations per conception and days open (CCI) were registered. Inseminations were similar in animals scoring 1, 2, 3, and 5, while they increased in cows with a score of 4, which also increased their CCI along with animals that scored 5. Positive correlations were observed between LS and reproductive variables. The herd's conception rate was reduced from 45% to 21.8% in the presence of clinical lameness (score ≥ 3). Applying the LS system should be essential as part of routine medical examinations used to monitor dairy herds, and it becomes even more crucial under hot-humid tropical environments, where adverse conditions could rapidly aggravate the early stages of lameness and not only increase the costs of hoof care, but also delay fertility in cattle.

Objective Assessment of Equine Locomotor Symmetry Using an Inertial Sensor System and Artificial Intelligence: A Comparative Study.

In horses, quantitative assessment of gait parameters, as with the use of inertial measurement units (IMUs) systems, might help in the decision-making process. However, it requires financial investment, is time-consuming, and lacks accuracy if displaced. An innovative artificial intelligence marker-less motion tracking system (AI-MTS) may overcome these limitations in the field. Our aim was to compare the level of agreement and accuracy between both systems and visual clinical assessment. Twenty horses underwent locomotion analysis by visual assessment, IMUs, and AI-MTS systems, under the following conditions: straight hard (SH), straight soft (SS), left and right circle hard (LCH, RCH), and soft (LCS, RCS). A greater number of horses were considered sound by clinical examination, compared to those identified as symmetric by the two gait analysis systems. More limbs were considered asymmetric by the AI-MTS compared to IMUs, suggesting its greater sensitivity. The greatest agreement between the two systems was found for the difference between two minima in vertical head position in SH, while the lowest for the difference between two minima in vertical pelvis position in SS, reflecting the difficulties in assessing asymmetry of the hindlimbs. It is unknown what degree of asymmetry is clinically relevant, suggesting that more consistent use in training horses may help determine the thresholds for asymmetry. Some degree of asymmetry may be clinically relevant, suggesting its regular use in training horses.

Revolutionizing Cow Welfare Monitoring: A Novel Top-View Perspective with Depth Camera-Based Lameness Classification.

This study innovates livestock health management, utilizing a top-view depth camera for accurate cow lameness detection, classification, and precise segmentation through integration with a 3D depth camera and deep learning, distinguishing it from 2D systems. It underscores the importance of early lameness detection in cattle and focuses on extracting depth data from the cow's body, with a specific emphasis on the back region's maximum value. Precise cow detection and tracking are achieved through the Detectron2 framework and Intersection Over Union (IOU) techniques. Across a three-day testing period, with observations conducted twice daily with varying cow populations (ranging from 56 to 64 cows per day), the study consistently achieves an impressive average detection accuracy of 99.94%. Tracking accuracy remains at 99.92% over the same observation period. Subsequently, the research extracts the cow's depth region using binary mask images derived from detection results and original depth images. Feature extraction generates a feature vector based on maximum height measurements from the cow's backbone area. This feature vector is utilized for classification, evaluating three classifiers: Random Forest (RF), K-Nearest Neighbor (KNN), and Decision Tree (DT). The study highlights the potential of top-view depth video cameras for accurate cow lameness detection and classification, with significant implications for livestock health management.

Deoxynivalenol and fumonisin predispose broilers to bacterial chondronecrosis with osteomyelitis lameness.

Bacterial chondronecrosis with osteomyelitis (BCO) lameness is the most critical animal health and welfare issue facing the broiler industry worldwide. It is estimated that 1 to 2% of bird condemnation at marketing age is caused by BCO lameness, resulting in tens of millions of dollars in annual losses. Fast-growing broilers are prone to mechanical stress that triggers bacterial translocation across epithelial barriers into the bloodstream, followed by bacterial colonization in the growth plate of long bones, and eventually, bone necrosis and lameness. Mycotoxins (MTX) are secondary metabolites produced naturally by microfungi, of which deoxynivalenol (DON), fumonisin (FUM), and zearalenone are the most prevalent in corn and soybean-meal-based diets. The presence of these mycotoxins in feed has been proven to reduce the barrier strength of the intestinal tracts and trigger immunosuppressive effects. In this study, we investigated the effects of the DON and FUM-contaminated feeds on the incidence of BCO lameness in broilers reared in both wire- and litter-floors. 720 one-day-old broiler chicks were assigned to the 2 × 2 factorial design: 2 MTX diets containing DON and FUM on wire flooring (MTX-W) and litter flooring (MTX-L), and 2 diets without MTX contamination on control wire flooring (CW) and control litter flooring (CL). Throughout the trial, the cumulative incidence of lameness per treatment was assessed by necropsying the lame birds. Birds in the MTX-W group had a higher incidence of lameness compared to those in CW (73.3% vs. 62.0%) (P < 0.05), and birds in the MTX-L group had a higher incidence of lameness compared to birds in CL (54.0% vs. 34.0%) (P < 0.05). MTX elicited net increases in BCO to a greater degree on litter (+20%) than on wire flooring (+12%). The increased incidence of BCO lameness in the MTX-W coincided with increased intestinal permeability supporting a correlation between intestinal barrier integrity and BCO lameness. To conclude, DON and FUM are predisposing factors for increasing BCO. However, no significant interaction exists between the diet and floor types in inducing lameness in broilers.

Exploring farmer and advisor lameness management behaviors using the COM-B model of behavior change.

Introduction: This paper applies the COM-B framework to farmer and farm advisor understandings and responses to lameness in sheep, beef, and dairy systems. It reflects on how farmers' and advisors' capability, opportunity, and motivation (COM-B) influence lameness management practices in these farming systems, and considers the interaction between these three factors, and stakeholders' behavior. Methods: Interviews with 29 farmers and 21 farm advisors in the north of England were conducted. Thematic analysis was undertaken with results categorized in relation to the COM-B framework focusing on barriers and enablers of lameness management. Use of the COM-B model provides a useful means of understanding the underlying behavioral mechanisms that contribute toward the persistence of lameness. This includes the complexities and interactions which hamper implementation of lameness management best practice. Results and discussion: The findings highlight three key areas to address with interventions to improve lameness management on farm: (1) removing physical and social barriers for lameness management; (2) improving psychological capability and motivation for lameness management; and (3) facilitating relationships and developing communication between farmers and advisors. In particular, the value of exploring both farmer and advisor perspectives on behavior in the animal health context is demonstrated. Future interventions should look to target these three areas to overcome barriers and focus on factors that enable positive lameness practices to occur.

Inducing experimental bacterial chondronecrosis with osteomyelitis lameness in broiler chickens using aerosol transmission model.

Lameness disease attributed to bacterial chondronecrosis with osteomyelitis in broilers affects production, animal welfare, and food safety in the poultry industry. The disease is characterized by necrotic degeneration of the rapidly growing femora and tibiae due to bacterial translocation from the respiratory or gastrointestinal tracts into the blood circulation, eventually colonizing the growth plate of the long bones. To investigate the etiology, pathogenesis, and intervention measures for BCO, developing an experimental model that reliably induces BCO lameness is of the utmost importance. In the past, we have employed a wire-flooring model and a litter-flooring model administered with a bacterial challenge to investigate strategies for mitigating BCO. However, multiple issues on labor-intensive barn setup and cleanout efforts for the wire-flooring system and concern of direct pathogenic exposure to the broilers for the litter-flooring models rendered these research models less effective. Thus, we investigated a new approach to induce experimental BCO lameness using an aerosol transmission model employing a group of birds reared on wire-flooring pens as a BCO infection source, and the disease is further disseminated through the airborne transmission to other birds reared on litter flooring in the same housing environment. The effectiveness of the aerosol transmission model in inducing BCO lameness was concluded from 4 independent experiments. The cumulative lameness generated from the BCO source group on the wire floors versus negative control treatments on the litter floors from Experiments 1, 2, 3, and 4 were 84% vs. 69.33%, P = 0.09; 54.55% vs. 60%, P = 0.56; 78% vs. 73.50%, P = 0.64; 81% vs. 74.50%, P = 0.11. Overall, the cumulative lameness generated from the wire floors was successfully transmitted to the birds on litter floors without significant statistical differences (P > 0.05). The effectiveness of the aerosol transmission model for experimentally triggering BCO lameness provides a reliable system for evaluating practical intervention strategies for BCO lameness in broilers.