The effect of lameness on milk production in dairy cows

Improving Lameness Detection in Cows: A Machine Learning Algorithm Application

The deployment of diverse data-generating technologies in livestock farming holds the promise of early disease detection and improved animal well-being. In this paper, we combine routinely collected dairy farm and herd data with weather and high frequency sensor data from 6 farms to predict new lameness events in various future periods, spanning from the following day to 3 weeks. A Random Forest classifier, using input features selected by the Boruta Algorithm, was used for the prediction task; effects of individual features were further assessed using partial dependence plots. We achieve precision scores of up to 93% when predicting lameness for the next 3 weeks and when using information from the last 3 weeks, combined with a balanced accuracy of 79%. Removing sensor data results have tendency to reduce the precision for predictions, especially when using information from the last one,2 or 3 weeks. Moving to a larger data set (without sensor data) of 44 farms keeps the similar balanced accuracy but reduces precision by more than 30%, revealing a substantial a trade-off in model quality between false positives (false lameness alerts) and false negatives (missed lameness events). Sensor data holds promise to further improve the precision of these models, but can be partially compensated by high resolution data from other systems, such as automated milking systems.

Dairy farmworkers' knowledge of the causes, risk factors, and clinical signs of bovine lameness

Background and Aim

Observing lameness in dairy cows is the primary animal-based indicator of their overall welfare and health status. The study evaluated dairy farmworkers' understanding of bovine lameness's causes, risk factors, and clinical symptoms in Kwa-Zulu Natal Province, South Africa.

Materials and Methods

Eleven dairy farms provided the data through questionnaires. The questionnaire consisted of five sections: The first section (A) gathered demographic data (age, gender, experience, level of study), and the second section (B) dealt with farm specifics (size, grazing method). Sections C, D, and E cover farm workers' knowledge of lameness risk factors, clinical signs of lameness, and treatment and management of lameness, respectively.

Results

About 85.5% of horses experience lameness during summer, contrasted to 15% during autumn. The seasonal results were statistically significant (p < 0.05). 93% of respondents identified a decrease in appetite as the most common sign of lameness, while 94% reported reduced milk yield and 90% increased lying time; a significant correlation was found between awareness of clinical signs and localities (p < 0.05). Age, gender, and occupation level (p < 0.05) were identified as contributing factors to the movement problem in the dairy industry, necessitating training for farm workers to enhance their knowledge.

Conclusion

Although there is a satisfactory (81%) understanding of lameness by farm workers. There is still need for improvement, hence, farm worker training and retraining are essential for managing and reducing the instances of bovine lameness.

Observational study evaluating the association of hoof trimming with dairy cattle behavior and milk yield in Canada and the United Kingdom

The objective of this observational study was to describe the associations between preventive hoof trimming (HT) of cows with no lesions and several behavior- and productivity-outcome measures including activity, lying behavior, and milk yield. A convenience sample of 4 freestall farms in the United Kingdom (n = 2) and Canada (n = 2) were recruited for the study. Inclusion criteria for herds included having a regular trim schedule and use of a specific pedometer system. Cows were trimmed as per their farm's regular protocol and schedule and all HT events were recorded. Only cows with no lesions present on the first recorded HT event were used in the analysis. Activity (steps/d), resting time (min/d), and resting bouts (bouts/d) were recorded daily by pedometers and total daily milk yield (kg/d) was recorded by the farm's milk recording system. Cow-level data such as DIM, breed, and parity were collected from the farm's herd management software. A generalized linear mixed repeated measures model with an exchangeable correlation structure was built to compare the outcome for 7 d following HT to baseline measures for each outcome of interest. For each outcome the average from the 5 d before HT was used as a baseline. All models included the baseline status, lactation number, season, farm, and DIM as covariates. Days from HT and its interaction with farm were included in all models. A total of 1,573 cows with no lesion recorded in their first HT were included in the analysis. Activity and resting time were inversely related on the day of HT, with activity increasing on 3 out of 4 farms (+59 to +84 steps/d) and resting time decreasing (-28 to -52 min/d). Following the day of HT, activity decreased to levels lower than those reported at baseline and resting time increased compared with baseline on most farms. There was a reduction in milk yield on the day of HT on 3 out of 4 farms and a reduction in average yield across the 7 d following trimming for all farms (range: 0.6 to 1.3 kg/d). Results were found to be farm dependent. The impact of the degree of change from baseline in behaviors and milk yield reported in this study on welfare of the cow is unclear, but the results suggest that alterations in the outcomes evaluated can persist beyond the day of trimming compared with baseline, necessitating further investigation.

Association between a genetic index for digital dermatitis resistance and the presence of digital dermatitis, heel horn erosion, and interdigital hyperplasia in Holstein cows

Digital dermatitis (DD) is a polybacterial disease endemic to most UK dairy farms. It poses a major financial and welfare threat and is characterized by high incidence and recurrence rates. We aimed to investigate the association between the UK EBV for resistance to digital dermatitis, the digital dermatitis index (DDI), and the frequency of DD, heel horn erosion (HHE), and interdigital hyperplasia (IH) in a population of Holstein dairy cows. We enrolled and genotyped 2,352 cows from 4 farms in a prospective cohort study. Foot lesion records were recorded by veterinary surgeons for each animal at 4 time points during a production cycle, starting at approximately 2 mo before calving and ending in late lactation. Importantly, these records were not used in the calculation of the DDI. Lesion records were matched to the animal's own DDI (n = 2,101) and their sire's DDI (n = 1,812). Digital dermatitis index values in our study population ranged from -1.41 to +1.2 and were transformed to represent distance from the mean expressed in SD. The relationship between the DDI and the presence of DD was investigated using a logistic regression model, with farm, parity, and a farm-parity interaction fitted as covariates. A multivariable logistic regression model was fitted to evaluate the relationship between HHE and DDI with farm fitted as a covariate. Finally, a univariable logistic regression model with DDI as explanatory variable was used to investigate the relationship between IH and DDI. The odds ratio of an animal being affected by DD was 0.69 for 1 SD increase in the animal's DDI (95% CI = 0.63-0.76). The odds of HHE and IH were 0.69 (95% CI = 0.62-0.76) and 0.58 (95% CI = 0.49-0.68) respectively for 1 SD increase in DDI. The adjusted probability of DD was 32% (95% CI = 27-36%) for cows with mean DDI value of 0, while it was 24% (95% CI = 20-29%) in cows with a DDI value of +1. Sire DDI breeding values were standardized in the same way and then binned into terciles creating an ordinal variable representing bulls of high, medium, and low genetic merit for DD resistance. The daughters of low genetic merit bulls were at 2.05 (95% CI = 1.60-2.64), 1.96 (95% CI = 1.53-2.50), and 2.85 (95% CI = 1.64-5.16) times greater odds of being affected by DD, HHE, and IH, respectively, compared with the daughters of high genetic merit bulls. The results of this study highlight the potential of digital dermatitis genetic indexes to aid herd management of DD, and suggest that breeding for resistance to DD, alongside environmental and management control practices, could reduce the prevalence of the disease.

Using Object-Oriented Simulation to Assess the Impact of the Frequency and Accuracy of Mobility Scoring on the Estimation of Epidemiological Parameters for Lameness in Dairy Herds

Mobility scoring data can be used to estimate the prevalence, incidence, and duration of lameness in dairy herds. Mobility scoring is often performed infrequently with variable sensitivity, but how this impacts the estimation of lameness parameters is largely unknown. We developed a simulation model to investigate the impact of the frequency and accuracy of mobility scoring on the estimation of lameness parameters for different herd scenarios. Herds with a varying prevalence (10, 30, or 50%) and duration (distributed around median days 18, 36, 54, 72, or 108) of lameness were simulated at daily time steps for five years. The lameness parameters investigated were prevalence, duration, new case rate, time to first lameness, and probability of remaining sound in the first year. True parameters were calculated from daily data and compared to those calculated when replicating different frequencies (weekly, two-weekly, monthly, quarterly), sensitivities (60-100%), and specificities (95-100%) of mobility scoring. Our results showed that over-estimation of incidence and under-estimation of duration can occur when the sensitivity and specificity of mobility scoring are <100%. This effect increases with more frequent scoring. Lameness prevalence was the only parameter that could be estimated with reasonable accuracy when simulating quarterly mobility scoring. These findings can help inform mobility scoring practices and the interpretation of mobility scoring data.

Sensitivity and specificity of mobility scoring for the detection of foot lesions in pasture-based Irish dairy cows

Lameness is an important production disease in dairy cows worldwide and has detrimental effects on cows' welfare, production, and reproductive performance, thus affecting the sustainability of dairy farming. Timely and effective detection of lameness allows for effective treatment, minimizing progression of disease, and maximizing the prognosis of recovery. Mobility scoring (MSc) is a 4 point (0-3) visual lameness scoring system that is the industry standard in several countries. However, few studies have examined the sensitivity (Se) and specificity (Sp) of MSc to detect foot lesions. The aim of this observational study was to determine the Se and Sp of MSc to detect foot lesions in dairy cattle in a pasture-based system. Five hundred ninety-five primi- and multiparous cows were randomly selected from 12 commercial Irish dairy farms and recruited for the study. Recruited cows were mobility scored and passed through a foot-paring crate where all 4 feet were lifted for examination. The team recorded the anatomical location and severity of any foot lesions present based on appearance only. Then, based on the type and severity of the lesions present, cows were classified according to 3 case definitions case definition 1: Any lesion present; case definition 2: Moderate lesions present (excluding minor lesions expected to have a low probability of affecting gait); and case definition 3: Severe lesions present (only including lesions most likely to result in a detectable gait abnormality). Sensitivity and Sp of MSc was calculated based on a threshold of MSc ≥2, defined as impaired (MSc = 2) or severely impaired (MSc = 3) mobility for each of the 3 case definitions, at the overall level and disaggregated by parity. The overall cow-level lesion prevalence based on the case definition 1 was 0.54 with significant between-herd variation. The overall Se and Sp of MSc for the detection of foot lesions were 0.18 and 0.96, 0.35 and 0.94, 0.43 and 0.94 for the case definitions 1, 2, and 3, respectively. Our findings showed poor Se, but high Sp of MSc for the detection of cows with foot lesions in a pasture-based system.

Associations of cow and farm characteristics with cow-level lameness using data from an extensive cross-sectional study across 3 structurally different dairy regions in Germany

The aim of the present study was to evaluate the associations between milk recording data, body condition score (BCS), housing factors, management factors, and lameness in freestall-housed dairy cows in 3 structurally different regions in Germany. These regions substantially vary regarding herd size, breeds, access to pasture, farm management (family run or company owned), and percentage of organic farms. The data used was collected in a large cross-sectional study from 2016 to 2019. A total of 58,144 cows from 651 farms in 3 regions of Germany (North, East, and South) was scored for locomotion and body condition. Additionally, data on milk yield, milk composition, breed, age, as well as information on housing and management were retrieved. One mixed-logistic regression model was fitted per region to evaluate the association of the data with the target variable "lame" and to allow for a comprehensive reflection across different kinds of farming types. In all regions, undercondition (BCS lower than recommended for the lactation stage; North: odds ratio [OR] 2.15, CI 1.96-2.34; East: OR 2.66, CI 2.45-2.88; South: OR 2.45, CI 2.01-2.98) and mid-lactation stage (102-204 d in milk; North: OR 1.15, CI 1.05-1.27; East: OR 1.24, CI 1.17-1.32; South: OR 1.38, CI 1.18-1.62) were associated with higher odds for lameness, whereas overcondition (BCS higher than recommended for the lactation stage; North: OR 0.51, CI 0.44-0.60; East: OR 0.51, CI 0.48-0.54; South: OR 0.65, CI 0.54-0.77) and parity of 1 or 2 was associated with lower odds (parity 1 = North: OR 0.32, CI 0.29-0.35; East: OR 0.19, CI 0.18-0.20; South: OR 0.28, CI 0.24-0.33; parity 2 = North: OR 0.51, CI 0.47-0.46; East: OR 0.41, CI 0.39-0.44; South: OR 0.49, CI 0.42-0.57), irrespective of the regional production characteristics. Low energy-corrected milk yield was associated with higher odds for lameness in South and North (North: OR 1.16, CI 1.05-1.27; South: OR 1.43, CI 1.22-1.69). Further factors such as pasture access for cows (North: OR 0.64, CI 0.50-0.82; and South: OR 0.65, CI 0.47-0.88), milk protein content (high milk protein content = North: OR 1.34, CI 1.18-1.52; East: OR 1.17, CI 1.08-1.28; low milk protein content = North: OR 0.79, CI 0.71-0.88; East: OR 0.84, CI 0.79-0.90), and breed (lower odds for "other" [other breeds than German Simmental and German Holstein] in East [OR 0.47, CI 0.42-0.53] and lower odds both for German Holstein and "other" in South [German Holstein: OR 0.62, CI 0.43-0.90; other: OR 0.46, CI 0.34 - 0.62]) were associated with lameness in 2 regions, respectively. The risk of ketosis (higher odds in North: OR 1.11, CI 1.01-1.22) and somatic cell count (higher odds in East: increased (>39.9 cells × 1,000/mL): OR 1.10; CI 1.03-1.17; high (>198.5 cells × 1,000/mL): OR 1.08; CI 1.01-1.06) altered the odds for lameness in 1 region, respectively. Cows from organic farms had lower odds for lameness in all 3 regions (North: OR 0.18, CI 0.11-0.32; East: OR 0.39, CI 0.28-0.56; South: OR 0.45, CI 0.29-0.68). As the dairy production systems differed substantially between the different regions, the results of this study can be viewed as representative for a wide variety of loose-housed dairy systems in Europe and North America. The consistent association between low BCS and lameness in all regions aligns with the previous literature. Our study also suggests that risk factors for lameness can differ between geographically regions, potentially due to differences in which dairy production system is predominantly used and that region-specific characteristics should be taken into account in comparable future projects.

The Effect of Lameness on Milk Production of Dairy Goats

Lameness on dairy goat farms is a welfare concern and could negatively affect milk production. This study's objective was to evaluate the effects of clinical lameness on the daily milk production of dairy goats. Between July 2019 and June 2020, 11,847 test-day records were collected from 3145 goats on three farms in New Zealand. Locomotion scoring of goats used a five-point scoring system (0 to 4). The dataset was split into two groups by lactation type, where goats were classified as being in seasonal lactation (≤305 days in milk) or extended lactation (>305 days in milk). A linear mixed model was used to analyze datasets using milk characteristics as the dependent variables. Severely lame goats (score 4) in seasonal and extended lactation produced 7.05% and 8.67% less milk than goats not lame, respectively. When the prevalence of severe lameness is between 5 and 20% of the herd, the estimated average daily milk income lost was between NZD 19.5 and 104 per day. This study established the negative impact of lameness on milk production and annual income in dairy goats on three farms.

Dairy cow hoof impact and slide measurements for common Ontario dairy farm floorings

In the context of understanding lameness and injury from slipping, our objective was to characterize hoof impact and slide of 5 cows walking on 6 flooring surfaces commonly used in Ontario dairy farms: diamond-grooved concrete (DC), sanded epoxy-covered concrete (EC), grooved rubber mat (GR), high-profile rubber mat (HR), low-profile rubber mat (LR), and turf grass (TG; Kentucky bluegrass/fescue mix). Surface hardness was measured on each surface using a Clegg Impact Soil Tester. Five trained lactating Holstein cows were each walked over all 6 surfaces sequentially in a randomized order. Walking speeds were determined from 60-fps videos. A 3-axis accelerometer attached to the lateral claw of each hindfoot captured continuous horizontal (aH), vertical (aV), lateral (aTLat), and medial (aTMed) accelerations at 2,500 Hz during each trial, from which peak values were identified. Data from 45°-rosette strain gauges glued to the dorsal surface of both medial and lateral hooves allowed for the calculation of principal strains (ε1 and ε2). From continuous data, several data points were extracted from 3 to 6 stances/trial: peak values of aH, aV, and aT for the impact phase of the stance; midstance values of ε1 and ε2 as proxies for force on the foot; magnitudes of normal (i.e., consistent and repeatable) sliding on the surface during the support phase; and 3 timing events to capture the cadence of the motion. All aH and aV signals were inspected onscreen to identify irregularities between the end of impact and beginning of breakover that indicated hoof slipping, which was observed on all surfaces. The effects on all measured variables of surface, cow, speed, and hoof (and all significant higher-order factors) were assessed by ANOVA in SAS 9.4 (SAS Institute Inc.), after verifying data normality. Values of aHmax, indicating grip on the surface from highest to lowest, ranked the surfaces in this order: LR, DC, HR, GR, EC, and TG. Ranking on aVmax, indicating most to least cushioning of the hoof on impact, ranked the surfaces in this order: DC, HR, GR, EC, LR, and TG. Differences in ranking among these and other significant impact variables indicate that future studies of lameness on different surfaces need to include all significant variables identified here. We detected no surface and strain interactions in either the ε1 or ε2 strain, indicating that the surfaces do not affect the overall loads on the foot at midstance. Additionally, lateral and medial hooves may have different roles in a stance. The results highlight the capacity to evaluate flooring types with this technology, and the study provides a tool for future work to examine the role of flooring types in the causation of lameness.

Effect of claw blocks on the healing duration and lesion severities of claw lesions in lame cows in Western Thailand

Background and Aim: Lameness is a major complication in dairy cattle affecting health and milk production. Several factors are found to contribute to this condition and specific treatments are required, including the process of claw trimming. The elevation of the claw, such as with the application of a claw block, was reported to be beneficial in the more severe cases. This study aimed to determine the efficiency of a claw block on claw lesions of lame cows in dairy farms in Western Thailand. Materials and Methods: Locomotion scores of 376 dairy cows were determined by a veterinarian using a scale of 1–5 (1 = normal; 5 = severely lame) at the time of the visit. Cows with a score of 3 or greater were defined as clinically lame. In total, 134 clinically lame cows from 11 dairy farms in the Kanchanaburi and Ratchaburi provinces were included in the analysis. Claw lesions included a white line abscess, bruised sole, sole ulcer, sole abscess, white line separate, and double soles. Wooden or rubber claw blocks were applied to the unaffected claw of the same hoof as the injured claw of 116 cows, which were classified as the treatment cases, and 18 cows were left untreated and classified as the control cases. Each cow was checked on every week of the healing process for 2 months unless the cow was culled earlier. Survival analysis was based on the Kaplan–Meier estimator and Cox Proportional Hazard regression. Results: The median healing time for lame cows with and without claw blocks was 21 and 36 days, respectively. After adjusting for the lesion severity and type, the lame cows with and without a claw block had hazard ratios of 2.16 and 3.08, respectively. The healing times between the four lesion types in cows with a claw block were not significantly different. The healing time was longer in lame cows, with a severity score of 4. Conclusion: The results from this study reveal that the treatment of lame cows with claw blocks promoted the healing capacity of claw lesions after claw trimming.

Association between Milk Electrical Conductivity Biomarkers with Lameness in Dairy Cows

Early identification of lameness at all phases of lactation improves milk yield and reduces the incidence of mastitis in the herd. According to the literature we hypothesized that there are associations of electrical conductivity variables of milk flow with lameness in dairy cows. The aim of this study was to determine if blood cortisol and electrical conductivity in the milk flow phases correlate with each other and whether they are related to cow lameness. On one farm, out of 1500 cows, 64 cows with signs of lameness and 56 healthy cows were selected with an average of 2.8 lactations and 60 days in the postpartum period. A local veterinarian who specializes in hoof care treatments identified and scored lameness. During evening milking, the milk flow of all 120 cows was measured using electronic milk flow meters (Lactocorder®, WMB AG, Balgache, Switzerland). Before each milking, two electronic mobile milk flow meters (Lactocorders) were mounted between the milking apparatus and the milking tube to take measurements. We found that the average cortisol concentration in the blood of the studied cows was significantly correlated with the laminitis score. Results of this study indicate that the number of non-lame cows with a milk electrical conductivity level of <6 mS/cm even reached 90.8−92.3% of animals. Milk electrical conductivity indicators ≥ 6 mS/cm were determined in 17.8−29.0% more animals in the group of lame cows compared to the group of non-lame cows. According to our study, we detected that blood cortisol concentration had the strongest positive correlation with milk electrical conductivity indicators. Cows with a greater lameness score had a higher cortisol content and milk conductivity.

Mastitis: Impact of Dry Period, Pathogens, and Immune Responses on Etiopathogenesis of Disease and its Association with Periparturient Diseases

Mastitis is an inflammation of the mammary gland initiated by pathogenic bacteria. In fact, mastitis is the second most important reason for the culling of cows from dairy herds, after infertility. In this review we focus on various forms of mastitis, including subclinical and clinical mastitis. We also stress the importance of the dry-off period as an important time when pathogenic bacteria might start their insult to the mammary gland. An important part of the review is the negative effects of mastitis on milk production and composition, as well as economic consequences for dairy farms. The two most important groups of bacteria that are involved in infection of the udder, Gram-negative and Gram-positive bacteria, are also discussed. Although all cows have both innate and adaptive immunity against most pathogens, some are more susceptible to the disease than others. That is why we summarize the most important components of innate and adaptive immunity so that the reader understands the specific immune responses of the udder to pathogenic bacteria. One of the most important sections of this review is interrelationship of mastitis with other diseases, especially retained placenta, metritis and endometritis, ketosis, and laminitis. Is mastitis the cause or the consequence of this disease? Finally, the review concludes with treatment and preventive approaches to mastitis.

Welfare of cattle during transport

In the framework of its Farm to Fork Strategy, the Commission is undertaking a comprehensive evaluation of the animal welfare legislation. The present Opinion deals with protection of cattle (including calves) during transport. Welfare of cattle during transport by road is the main focus, but other means of transport are also covered. Current practices related to transport of cattle during the different stages (preparation, loading/unloading, transit and journey breaks) are described. Overall, 11 welfare consequences were identified as being highly relevant for the welfare of cattle during transport based on severity, duration and frequency of occurrence: group stress, handling stress, heat stress, injuries, motion stress, prolonged hunger, prolonged thirst, respiratory disorders, restriction of movement, resting problems and sensory overstimulation. These welfare consequences and their animal-based measures are described. A variety of hazards, mainly relating to inexperienced/untrained handlers, inappropriate handling, structural deficiencies of vehicles and facilities, poor driving conditions, unfavourable microclimatic and environmental conditions, and poor husbandry practices leading to these welfare consequences were identified. The Opinion contains general and specific conclusions relating to the different stages of transport for cattle. Recommendations to prevent hazards and to correct or mitigate welfare consequences have been developed. Recommendations were also developed to define quantitative thresholds for microclimatic conditions within the means of transport and spatial thresholds (minimum space allowance). The development of welfare consequences over time was assessed in relation to maximum journey duration. The Opinion covers specific animal transport scenarios identified by the European Commission relating to transport of unweaned calves, cull cows, the export of cattle by livestock vessels, the export of cattle by road, roll-on-roll-off ferries and 'special health status animals', and lists welfare concerns associated with these.

Cow culling patterns in eight commercial Estonian dairy herds and farmers' behaviour in reporting culling reasons

The present study aimed to reveal the culling-related metrics, identify the culling reason patterns for cows by developing and implementing the cow culling form (CCF), and analyse the concordance of farmers' stated culling reasons with those identified based on the CCF. A CCF was developed to register the disease history and conditions of cows that were related to culling. CCFs were completed by farm managers and veterinarians in eight dairy herds over a one-year period for slaughtered (n = 686) and dead (n = 250) cows. Completed CCFs were interpreted by the study authors to identify underlying, intermediate, influential, and immediate culling reasons. The identified culling reasons were compared to those reported by producers. The mean annual cow culling rate of the study farms was 31.8%, and the average on-farm mortality was 9.3%. Of the 250 cows that died on the farms, 43.6% were euthanised. Only 2% of the cows were slaughtered due to low milk yield. In total, 260 and 119 unique three-reason culling codes were created for slaughtered and dead cows, respectively. Single disease or condition causing slaughter or death of cows was identified in 44.8% and 52.0% of the cases, respectively. Producers' reported culling reasons concurred with the underlying culling reason in 72.6% and 63.6% of slaughtered and dead cows, respectively. A high variety of agreements between the farmers' reported and CCF-based culling codes was identified across single culling reasons. Improved registration of culling reasons is required to support informed herd-based decisions.

Measuring lameness prevalence: Effects of case definition and assessment frequency

Lameness assessments are commonly conducted at a single point in time, but such assessments are subject to multiple sources of error. We conducted a longitudinal study, assessing the gait of 282 lactating dairy cows weekly during the first 12 wk of lactation, with the aim of assessing how lameness prevalence changed in relation to case definition and assessment frequency. Gait was scored using a 5-point scale where scores of 1 and 2 were considered sound, 3 was clinically lame, and 4 and 5 were severely lame. We created 5 lameness definitions using increasingly stringent thresholds based upon the number of consecutive events of locomotion score ≥3. In LAME1, a cow was considered lame when locomotion score was ≥3 at any scoring event, in LAME2, LAME3, LAME4, and LAME5, a cow was considered lame when locomotion score was 3 or higher during 2, 3, 4, and 5 consecutive scoring events, respectively. We also assessed the effect of assessment frequency on measures of prevalence and incidence using weekly assessment (ASSM1), 1 assessment every 2 wk (ASSM2), 1 assessment every 3 wk (ASSM3), and 1 assessment every 4 wk (ASSM4). Using LAME1, 69.2% of cows were considered lame at some point during the trial, with an average point prevalence of 31.8% (SD: 2.8) and average incidence rate of 10.9 cases/100 cow weeks (SD: 3.7). Lameness prevalence decreased to 28.0% when using LAME5. Survival analysis was used to assess the effects of parity, using these different case definitions. Parity is a known risk for lameness, such that case definitions and prevalence estimates should be stratified by parity to inform management decisions. Using the LAME3 criterion, primiparous cows had the highest chance of reaching 12 wk without a lameness event, and fourth and higher parities had the lowest. Weighted linear and quadratic kappa values were used to assess agreement between different assessment frequencies and lameness definitions; we found substantial to excellent agreement between ASSM1 and ASSM2 using LAME1, LAME2, and LAME3 definitions. Agreement was fair to substantial between ASSM1 and ASSM3 and low to fair between ASSM1 and ASSM4. Likewise, the agreement between LAME1 and LAME2 was fair in primiparous cows, substantial in second and third parity cows, and poor to fair in fourth and greater parity cows. We conclude that lameness prevalence estimates are dependent upon case definition and that the use of more stringent case definitions results in fewer cows classified as lame. These results suggest that routine locomotion assessments be conducted at least every 2 wk, and that cows should be defined as lame on the basis of 2 consecutive assessments.

Conformation traits of Holstein cows and their association with a Canadian economic selection index

Pro$ is a Canadian economic selection index aimed to maximize profit by increasing production yields, while maintaining conformation and functional traits. Currently, there is an interest in understanding the individual contributions of conformation traits recorded in Canada to the overall economic value of a cow and whether they are equally important. We used multiple polynomial regression and principal component analysis to assess the association of 26 conformation traits with Pro$ using Relative Breeding Values (RBV) from 9,351 proven bulls. The best reduced regression model explained 72.5% of the Pro$ variance, with heel depth and body depth having the highest and lowest effect on Pro$ values, respectively. Four traits classified as intermediate optimum traits, e.g., teat length, showed significant linear association with Pro$ instead of quadratic, whereas bone quality was not significantly associated with the index. Principal component analysis indicated that highly profitable bulls share similar RBV, with a sub-clustering of bulls of daughters with better mammary system versus better dairy strength and feet and legs. These results provide understanding of the individual contributions of conformation traits to Pro$ and give information to guide the Canadian dairy industry on how to best consider these traits in recording and genetic evaluation programs.

Lameness in Dairy Cow Herds: Disease Aetiology, Prevention and Management

As livestock production systems have changed to intensive commercial structures to meet the increasing demand for animal-based products, there has been an increase in food production diseases, subsequently resulting in animal welfare issues. After mastitis and infertility, lameness is one of the three major issues affecting dairy cattle globally, resulting in reduced productivity, economic losses, and animal welfare problems. Lameness is associated with reduced milk yield, lack of weight gain, poor fertility, and frequently, animal culling. Environmental (temperature, humidity) and animal risk factors contribute to disease severity, making this multifaceted disease difficult to eradicate and control. As such, prevalence rates of lameness in dairy herds ranges from 17% to 35% globally. Clinical lameness is often treated with antibiotic therapy, which is undesirable in food-producing animals, as outlined in the One Health and the European Farm to Fork food sustainability goals. Lameness is not a single disease in dairy cows but is the manifestation a range of issues, making lameness control one of the greatest challenges in dairy farming. Lameness prevention, therefore, must be a key focus of farm management and sustainable food production. There is an urgent need to establish farm-level aetiology of disease, promote the recognition of lameness, and implement effective control measures to lower incidence and transmission of disease within herds.

Evaluating Alternatives to Locomotion Scoring for Detecting Lameness in Pasture-Based Dairy Cattle in New Zealand: In-Parlour Scoring

Earlier detection followed by efficient treatment can reduce the impact of lameness. Currently, locomotion scoring (LS) is the most widely used method of early detection but has significant limitations in pasture-based cattle and is not commonly used routinely in New Zealand. Scoring in the milking parlour may be more achievable, so this study compared an in-parlour scoring (IPS) technique with LS in pasture-based dairy cows. For nine months on two dairy farms, whole herd LS (4-point 0−3 scale) was followed 24 h later by IPS, with cows being milked. Observed for shifting weight, abnormal weight distribution, swollen heel or hock joint, and overgrown hoof. Every third cow was scored. Sensitivity and specificity of individual IPS indicators and one or more, two or more or three positive indicators for detecting cows with locomotion scores ≥ 2 were calculated. Using a threshold of two or more positive indicators were optimal (sensitivity > 92% and specificity > 98%). Utilising the IPS indicators, a decision tree machine learning procedure classified cows with locomotion score class ≥2 with a true positive rate of 75% and a false positive rate of 0.2%. IPS has the potential to be an alternative to LS on pasture-based dairy farms.

Prospective cohort study of the association between early lactation mastitis and the presence of sole ulcers in dairy cows

BACKGROUND

The objective of this study was to investigate the association between (sub)clinical mastitis (CM) in the first 30 days in milk (DIM) and the presence of sole ulcers (SU) later in lactation.

METHODS

Holstein cows and heifers were examined for presence of sole haemorrhage and SU before calving, in the first 14 days postcalving and in early lactation (after 30 DIM). CM episodes and somatic cell counts (SCC) measurements were obtained from farm records. Multivariable logistic regression was used for data analysis.

RESULTS

Odds of SU in early lactation were 2.44 times greater (95% confidence interval [CI] 0.97-5.54) in cows that had CM in the first 30 DIM compared to cows that did not have CM in the first 30 DIM. When cows that had SU precalving or at the calving check were excluded from the dataset, an association of CM in the first 30 DIM with later presence of SU was no longer statistically significant but the same numeric trend still existed (odds ratio [OR] 2.25, 95% CI 0.81-5.34). The odds of SU in early lactation were 1.70 times greater in cows that had high SCC compared to cows that did not have high SCC in the first 100 DIM (95% CI 1.13-2.55).

CONCLUSION

An association was found between CM in the first 30 DIM and presence of SU in early lactation (after 30 DIM). Elucidating the mechanism behind this relationship could improve our understanding of the aetiopathogenesis of both diseases and lead to new preventive strategies.

Antimicrobials use and their indications in dairy farm and individual farmer production conditions in southern India

Antimicrobials use (AMU) is the key driver for development of antimicrobials resistant (AMR) pathogen in human and veterinary medicines. Therefore, understanding AMU pattern is prerequisite for focused intervention on AMR. The aim of this study was to understand the AMU pattern and their indications in dairy farm and individual farmer production conditions in southern India. Treatment registers of 6 years (2012 to 2017) containing 3178 cases from dairy farm and 12,057 cases during 2017-2019 under individual farmer production conditions were collected and analyzed by log-linear model. Seasons were classified as rainy (Jul-Oct), winter (Nov-Feb), and summer (Mar-June) as per climatic conditions in the study area. It is observed that mastitis, lameness, and reproductive problems were major health disorders among treated animals in farm and individual farmer production conditions. Season had significant influence on proportional rates of various health disorders in crossbred cows under both the production conditions. AMU pattern was different between the breeds and production conditions. Antibiotics were the most commonly used group of drugs (23-28%) than non-steroidal anti-inflammatory drugs (20%), antihistamine (17%), and nutrient supplements (14-16%). Antibiotics were mostly used for mastitis (47-67%) than other conditions like fever (18%), reproductive problems (15%), and lameness (16%). For treating mastitis, cephalosporins and gentamicin were most commonly used under individual farmer production condition, while penicillin group was frequently used in farm. It is concluded that mastitis is the most common indication for AMU in dairy animals and thus developing appropriate guidelines for mastitis treatment and control is necessary to reduce overall AMU.

Evaluating Alternatives to Locomotion Scoring for Lameness Detection in Pasture-Based Dairy Cows in New Zealand: Infra-Red Thermography

Simple Summary

Early detection accompanied by effective treatment is vital to minimise the negative impacts of lameness in dairy cows. Locomotion scoring is commonly used for detecting lameness but can be challenging to implement effectively in cows at pasture-based systems. One potential alternative detection is measuring foot skin temperature using an infrared camera. Data were collected from a 940-cow dairy farm in New Zealand with cows observed at two consecutive afternoon milkings. Locomotion scoring was undertaken at the first milking and thermal imaging of the hind feet at the second milking. As the locomotion score increased, mean foot skin temperature increased, showing that measuring temperature could be a useful alternative to locomotion scoring. However, the process needs to be speeded up and automated if it is to be used widely.

Abstract

Lameness in cattle is a complex condition with huge impacts on welfare, and its detection is challenging for the dairy industry. The present study aimed to evaluate the association between foot skin temperature (FST) measured using infrared thermography (IRT) and locomotion scoring (LS) in dairy cattle kept at pasture. Data were collected from a 940-cow dairy farm in New Zealand. Cows were observed at two consecutive afternoon milkings where LS was undertaken at the first milking (4-point scale (0–3), DairyNZ). The next day, cows were thermally imaged from the plantar aspect of the hind feet using a handheld T650sc forward-looking infrared camera (IRT). The association between FST and locomotion score was analysed using a generalised linear model with an identity link function and robust estimators. ROC curves were performed to determine optimal threshold temperature cut-off values by maximising sensitivity and specificity for detecting locomotion score ≥ 2. There was a linear association between individual locomotion scores and FST. For mean temperature (MT), each one-unit locomotion score increase was associated with a 0.944 °C rise in MT. Using MT at a cut-off point of 34.5 °C produced a sensitivity of 80.0% and a specificity of 92.4% for identifying cows with a locomotion score ≥ 2 (lame). Thus, IRT has a substantial potential to be used on-farm for lameness detection. However, automation of the process will likely be necessary for IRT to be used without interfering with farm operations.

Review of guidelines for functional claw trimming and therapeutic approach to claw horn lesions in cattle

Lameness is one of the most pressing health and welfare problems in cattle, especially on dairy farms. The most common cause of lameness is claw pathology, often due to lack of appropriate functional claw trimming. Functional claw trimming restores the physiological shape of the claws and distributes weight properly between the claws and over the claw weight-bearing surface. It also allows closer examination of the claws for early signs of pathology. The methods of functional claw trimming described in the previous century are still applicable today, considering some recent findings on the subject. It is essential not to over-trim the claws and to maintain strict hygiene of the trimming tools. Claw horn pathology in the early stages is usually treated effectively by therapeutic claw trimming alone. The stoic nature of cattle and their natural tendency to hide pain often result in delayed treatment of claw diseases, leading to more advanced stages of disease/pathology associated with higher-grade lameness. This situation often leads to the development of neuropathic pain and hyperalgesia requiring multimodal treatment. Because claw horn diseases are multifactorial, veterinarians and others involved in animal management must be familiar with the preventive measures available to improve claw health in a cattle herd. Further research to improve claw horn quality and effectively control/prevent claw infections without polluting the environment or negatively affecting worker and animal health is still needed. This article reviews the latest knowledge on functional claw trimming and treatment of the most common claw horn diseases in cattle.

Lameness in Early Lactation Is Associated with Lower Productive and Reproductive Performance in a Herd of Supplemented Grazing Dairy Cows

Simple Summary

It has been reported that the detrimental impact of clinical diseases, such as mastitis, on lactation and reproduction is highest when the first clinical case occurs in early lactation. Therefore, we run an observational study on 7156 lactations from highly supplemented grazing dairy cows to evaluate the association of the timing of lameness case occurrence in lactation with productive and reproductive performances in dairy cows. We found that cows getting lame before the first service produced less milk than cows getting lame later in lactation (i.e., after the first service), and that both groups of lame cows produced less milk than healthy ones. We also found that cows becoming lame after the first service had an 87 d longer calving to pregnancy interval than healthy herd mate cows and that cows turning lame before the first service had an 38 d longer calving to pregnancy interval than healthy herd mates. In conclusion, the timing of lameness case occurrence in lactation is associated with its impact on productive and reproductive performances in dairy cows.

Abstract

The main aim of this study was to assess the associations between the timing of lameness clinical case occurrence in lactation with productive and reproductive performances in grazing Holstein cows. A cohort study was carried out on a dataset with records from a commercial dairy herd (Buenos Aires, Argentina) for cows that calved and were dried off from January 2010 through June 2017. The first recorded event of lameness per lactation was considered for the study. Criteria for lactation inclusion included not having uterine diseases, mastitis, or anovulatory cysts during the studied risk period (i.e., up to 200 DIM). Therefore, a total of 7156 out of 20,086 lactations were included in the statistical analysis. The association between lameness case occurrence in lactation (cows not lame (LG0) vs. lame cows between parturition and first service (LG1) vs. lame cows between first service and first pregnancy (LG2)) with productive (i.e., accumulated milk yield to 150 DIM (MILK150) and 300 DIM (MILK305)) and reproductive performances (hazard of insemination and pregnancy) was analyzed with linear regression models and proportional hazard regression models, respectively. Lame cows produced 161 and 183 kg less MILK150 and MILK305 than non-lame herd mates, respectively. Moreover, LG1 cows produced 216 kg less MILK150 and 200 kg less MILK305 than LG0 cows, and LG2 cows also produced 58 kg less MILK150 and 158 kg less MILK305 than LG0 cows. The LG1 cows had a lower hazard of service than LG0 cows (HR = 0.43, 95%CI = 0.39–0.47). Furthermore, LG1 cows had a lower hazard of pregnancy than LG0 cows (HR = 0.52, 95%CI = 0.46–0.59) and took longer to get pregnant than LG0 cows (median [95%CI], 139 [132–144] vs. 101 [99–103]). Moreover, LG2 cows had a much lower hazard of pregnancy than LG0 cows (HR = 0.08, 95%CI = 0.05–0.12) and much longer calving to first pregnancy interval than LG0 cows (188 [183–196] vs. 101 [99–103]). In conclusion, cows that become lame in early lactation produce less milk and have lower hazards of insemination and pregnancy than herd mates that are healthy or become lame later in lactation. In addition, cows that become lame immediately after the voluntarily waiting period have the poorest reproductive performance (i.e., they have the lowest hazard of pregnancy and the longest calving to pregnancy interval).

Lameness in dairy cows: farmer perceptions and automated detection technology

This Research Reflection provides an overview of three interrelated topics: (i) lameness in dairy cows, demonstrating the underpinning importance of the condition, (ii) dairy farmer detection, diagnosis and treatment of lameness and associated foot lesions as well as dairy farmer perceptions towards the condition and (iii) lameness detection technologies, and their potential application on farm to automate the detection of lameness in commercial dairy herds. The presented literature clearly demonstrates that lameness is a major health issue in dairy herds, compromising dairy cow welfare and productivity, and resulting in significant economic implications for dairy farmers. Despite this, dairy farmers fail to perceive lameness as a serious threat to their dairy business. This restricted perception of the importance of lameness may be a product of limited ability to detect lame cows. Many automated lameness detection technologies have been proposed to assist dairy farmers in managing their herds. However, limitations such as cost, performance and dairy farmer perception of the usefulness of these technologies, has lead to poor uptake. It can, therefore, be concluded that there is a need to more thoroughly evaluate the effectiveness of these technologies under on-farm conditions, potentially in the form of a demonstration farm network. This will allow generation of the necessary data required to show dairy farmers that these technologies are reliable and are economically rational for their dairy business.

Current attitudes of veterinarians and producers regarding the use of local and systemic analgesia in beef and dairy cattle in the United States

OBJECTIVE

To survey cattle producers and veterinarians about the use of analgesia on US cattle operations.

SAMPLE

1,187 members of the following database, electronic mailing lists, and social media groups: FarmProgress master file, American Association of Bovine Practitioners, Academy of Veterinary Consultants, National Milk Producers Federation Farm Evaluators, Dairy Moms Facebook group, and Dairy Girl Network Facebook group.

PROCEDURES

An online survey was developed to gather information about the frequency of local and systemic analgesia use for common painful procedures and diseases in cattle < 2, 2 to 12, and > 12 months old. Respondents also rated their extent of agreement with each of 10 statements related to pain management in cattle. The survey was available from June 11 to August 10, 2018. Descriptive data were generated. Logistic regression was used for comparisons among cattle age groups and respondents on the basis of their industry role.

RESULTS

In general, frequency of analgesia use increased as cattle age increased, regardless of the procedure or disease. The odds of analgesia use were lower for men, compared with women, and greater for veterinarians, compared with producers. Many respondents indicated they were cognizant of the benefits of analgesia use in cattle but perceived federal regulations and drug costs as impediments to the implementation of pain mitigation protocols on cattle operations.

CONCLUSIONS AND CLINICAL RELEVANCE

Results provided insight into current perceptions and use of analgesia in cattle, which can be used to guide implementation of pain mitigation protocols on US beef and dairy cattle operations.

The hidden cost of disease: II. Impact of the first incidence of lameness on production and economic indicators of primiparous dairy cows

Lameness is a persistent and underreported health and welfare problem in the dairy industry, resulting in reduced cow performance and profitability as well as early culling. The study objectives were (1) to quantify the impact of the first instance of lameness, at different stages of lactation, on production and economic performance, and (2) to further quantify the impacts of the first instance of lameness when only cows that remain in the herd for at least 100 d in milk (DIM) and those that remain for 305 DIM are included in the analysis. A retrospective longitudinal study was conducted using pre-existing data from animal health records and Dairy Herd Improvement Association records. Data were edited based on selected inclusion criteria, yielding a data set containing records from 15,159 first-lactation Holstein cows from 120 herds with year of first calving between 2003 and 2014. Lame cows were assigned to 1 of 4 groups based on when in the lactation the first event of lameness occurred: transition (1-21 DIM), early lactation (22-100 DIM), mid-lactation (101-200 DIM), or late lactation (201+ DIM). Mid- and late-lactation lame cows were also stratified by cumulative milk yield before the lameness event. Healthy cows (i.e., no recorded lameness event) were randomly assigned for each lactation stage, with mid-lactation healthy and late-lactation healthy cows similarly stratified. Production performance (cumulative milk, fat, and protein yield) and economic performance [milk value, margin over feed cost (MOFC), and gross profit] were analyzed using a mixed model with herd as a random effect. Cumulative milk yields were 811 to 1,290 kg lower for lame cows than for healthy cows, with milk component yields undergoing similar reductions. Reductions in milk yield contributed to losses in milk value (-Can$527 to -Can$1,083; -US$419 to -US$862) and MOFC (-Can$510 to -Can$774; -US$406 to -US$616). Higher losses were reported using gross profit (-Can$753 to -Can$1,052; -US$599 to -US$837), which includes all lameness-related costs. Production and performance losses were smaller when 100 DIM and 305 DIM thresholds were applied (i.e., exclusion of cows culled before 100 and 305 DIM, respectively), however, mid- and late-lactation lame cows maintained high levels of significant losses for all 6 variables analyzed. Lameness also led to higher levels of culling, masking losses for transition and early-lactation lame cows in the 305-DIM analysis. Increasing producer understanding of the costs associated with lameness not only serves to provide insight to producers for more informed culling decisions, but may also help producers weigh the costs of adopting new methods and technologies targeted at reducing on-farm lameness.

Changes in the soft-tissue thickness of the claw sole in Holstein heifers around calving

Claw horn disruption lesions are a common cause of lameness in dairy cattle. It is commonly agreed that they develop due to excessive pressure from the distal phalanx on the horn-producing tissue in the sole. The distal phalanx is supported by the suspensory apparatus, a large proportion of which is made up of connective tissue. It has been hypothesized that increased laxity of the connective tissue due to hormonal changes around calving may lead to decreased support of the distal phalanx, resulting in a sinking of the bone and increased pressure on the horn-producing tissue. In this longitudinal study, our first objective was to determine whether the thickness of the soft tissue related to the claw sole (the combined depth of the digital cushion and corium; soft-tissue thickness, STT) in the weight-bearing hind claws of live heifers changed around calving (the period from approximately 3 wk before calving to 2 wk after calving). Our second objective was to evaluate the relationship between the body condition score (BCS) of recruited heifers and the STT estimates we obtained. We measured STT (defined as the distance between the distal phalanx and the sole horn) in the apex and the posterior part of the sole of the hind claws of 34 Holstein heifers 4 times over 3 to 4 wk around calving. We determined STT by ultrasonographic measurements through the sole horn on weight-bearing claws. The overall mean STT at site 1 was 3.3 mm [minimum-maximum (min-max): 1.8 to 5.2 mm], and the mean at site 2 was 3.7 mm (min-max: 2.2 to 5.8). The overall mean STT was thickest in the first examination before calving [site 1: 3.4 mm (min-max: 1.9 to 4.7); site 2: 4.1 mm (min-max: 2.7 to 5.8)] and thinnest at site 1 in the second examination after calving (3.2 mm, min-max: 1.8 to 5.2) and at site 2 at the first examination after calving (3.5 mm, min-max: 2.2 to 5.0). We observed an average reduction in STT of -0.2 mm (min-max: 0.8 to -0.9 mm) at site 1 during the study period, but we did not observe this reduction in all animals. At site 2, we found an average reduction in STT of -0.6 mm (min-max: 0.8 to -1.3 mm) from 10 d before calving to 5 d after calving, corresponding to a decrease of approximately 15% (min-max: 0 to 31%). We suggest that this reduction was caused by a rotation of the distal phalanx toward the posterior part of the sole horn in the weeks around calving. During the same period, heifer BCS decreased between 0.25 and 0.5 increments in the BCS scale, but we found no correlation between BCS and STT. However, the heifers experienced many changes related to management, feeding, and time budget during the study period, and the rotation of the distal phalanx and reduction of the STT might be explained not only by calving but also by other factors that affect heifers and their claws during the transition period.

Slightly and Moderately Lame Cows in Tie Stalls Behave Differently From Non-lame Controls. A Matched Case-Control Study

Lameness affects dairy cows worldwide and is usually associated with pain. Behavioral differences in lame compared to non-lame tie-stall-housed dairy cows might be less pronounced than in free-stall-housed, since the principle demands to a cow's locomotor system and thus the impact of lameness on behavior seem to be lower in tie stalls. Behavioral differences between lame and non-lame cows might be used to estimate the impact of lameness on the well-being of tied dairy cows. In the current study, lame cows were categorized as locomotion scoring between 2.25 and 3.25 on a 1–5 scale. The aim was to compare the eating, rumination and lying behavior of lame cows against non-lame tied dairy cows, in order to draw conclusions on the association of lameness, behavior and well-being in tied dairy cows. The eating and rumination behavior of 26, the lying behavior of 30, and the relative upright and lying activities of 25 matched case-control pairs were analyzed, considering the matching criteria farm, breed-type, and parity-group. Lame cows had fewer [mean of the pairwise differences (case–control) (mean_diff) = −2.6 bouts, CI_95% (−3.8–−1.4) bouts, p = 0.001], but longer lying bouts [mean_diff = 26.7 min per bout, CI_95% (10.1–43.4) min per bout, p = 0.006]. The lying time was shorter [mean_diff = −64.7 min, CI_95% (−104.4–−24.9) min, p = 0.006] in lame cows compared to their non-lame controls. Lame cows had a shorter eating time [mean_diff = −27.7 min, CI_95% (−51.5–−4.0) min, p = 0.042] and spent a larger proportion of their upright time ruminating [mean_diff = 7.2%, CI_95% (3.2–11.1)%, p = 0.001] instead of eating. The results of the current study indicate that the eating, rumination, and lying behavior of lame tied dairy cows is altered. These findings indicate that slight and moderate lameness (locomotion score between 2.25 and 3.25 on a 1–5 scale) are likely to be associated with an impaired well-being in affected tied dairy cows. This underlines the need to continuously reduce the lameness prevalence and severity in tied dairy herds.

Randomized controlled trial comparison of analgesic drugs for control of pain associated with induced lameness in lactating dairy cattle

Both the economic loss and welfare implications of lameness affect the dairy industry. Currently no analgesic drugs are approved to alleviate lameness-associated pain in lactating dairy cattle in the United States. In this randomized controlled trial, 48 lactating Holsteins were enrolled to evaluate the effect of oral meloxicam and i.v. flunixin meglumine on induced lameness. Cows were allocated to 1 of 4 treatment groups (n = 12 per group): lameness and flunixin meglumine (LAME + FLU); lameness and meloxicam (LAME + MEL); lameness and placebo (LAME + PLBO); or sham induction and placebo (SHAM + PLBO). Six hours before treatment, arthritis-synovitis was induced in the distal interphalangeal joint with 20 mg of amphotericin B, whereas SHAM cows were given an intra-articular injection of an equal volume (4 mL) of isotonic saline. Cows in LAME + FLU received 2.2 mg/kg flunixin meglumine i.v. and whey protein placebo orally; LAME + MEL were administered 1 mg/kg meloxicam orally and 2 mL/45 kg sterile saline placebo i.v.; LAME + PLBO were administered 2 mL/45 kg sterile saline placebo i.v. and whey protein placebo orally; and SHAM + PLBO received 2 mL/45 kg sterile saline placebo i.v. and whey protein placebo orally. The initial treatment of MEL, FLU, or PLBO was identified as time 0 h and followed by a second dose 24 h later with data collection for 120 h. The methods used to assess analgesic efficacy were electronic pressure mat, visual lameness assessment, visual analog score, plasma cortisol concentration, plasma substance P concentration, mechanical nociception threshold, and infrared thermography imaging. Linear mixed effect modeling was the primary method of statistical analysis. Visual lameness scoring indicated a lower proportion of the FLU + LAME group was lame at the T2 h and T8 h time points in comparison to the positive controls, whereas MEL therapy resulted in a lower proportion of lame cows at the T8 h time point. Cortisol area under the effect curve was lower following FLU therapy compared with LAME + PBLO for the 0-2 h (LSM difference = 35.1 ng·h/mL, 95% CI: 6.8, 63.3 ng·h/mL), 2-8 h (LSM difference = 120.6 ng·h/mL, 95% CI: 77.2, 164.0 ng·h/mL), and 0-24 h (LSM difference = 226.0 ng·h/mL, 95% CI: 103.3, 348.8 ng·h/mL) time intervals. Following MEL therapy, cortisol area under the effect curve was lower than LAME + PLBO for both the 2 to 8 h (LSM difference = 93.6 ng·h/mL, 95% CI: 50.2, 137.0 ng·h/mL) and 0 to 24 h time intervals (LSM difference = 187.6 ng·h/mL, 95% CI: 64.9, 310.4 ng·h/mL). Analysis of data from other assessment modalities failed to discern biologically relevant differences between treatment groups. We conclude that meaningful differences were evident for visual lameness assessment and cortisol from MEL and FLU treatment versus the positive control. Further clinical research is needed toward development of a model that will create reproducible events that are more pronounced in severity and duration of lameness which can be validated as a substitute for naturally occurring lameness cases.

Invited review: Academic and applied approach to evaluating longevity in dairy cows

In its simplest form, longevity is defined as the ability to live a long life. Within the dairy industry, longevity has been defined and measured in many different ways, and the aim of this review is to disentangle the definitions and provide some clarity. Using a more standardized approach for defining and measuring longevity, both in academic discussions and on-farm application, we suggest using herd life (days) for time from birth until culling, and length of productive life (days) for time from first calving until culling. Despite identified benefits of extending the length of productive life, global trends in the time spent by dairy cattle in the herd have mostly been negative. Factors influencing herd life, such as health, rearing, environmental conditions, and management, are often ignored when longevity goals are evaluated, thereby underestimating the effect these factors have on defining overall longevity. Also, production efficiency, herd profitability, and welfare are not necessarily served by the longest life but rather by the optimized length of herd life instead. The majority of research has focused on the role of genetics on longevity. In this review, we provide insight into influences affecting dairy cow herd life as well as farm- and cow-level factors associated herewith. Finally, we suggest using herd life, including reproduction, production, health, and youngstock performance, for farm-level evaluation and length of productive life for time spent in the lactating herd.

Pre-weaning management of calves on commercial dairy farms and its influence on calf welfare and mortality

Welfare and management of calves is of increasing interest and also influences performance of these animals in later life. The aim of this study was to assess management and environmental conditions under which pre-weaned dairy calves are reared on commercial Irish dairy farms. We included 47 spring-calving, pasture-based herds in this study. Herd and animal-specific data, such as mortality rate, age and breed, were gathered from all participants via the HerdPlus® database. Information pertaining to management practices was collected by conducting an interview with the principal calf rearer, while an assessment of calf housing facilities was conducted to identify conditions calves were reared in. The environmental assessment included measurements of space allowance per calf, as well as feeding equipment hygiene. To assess calf behaviour video observations were used, while accounting for the number of calves present in a group and the space available per calf. Faecal samples were also collected to determine the presence of enteric pathogens among calves. To compare calf space allowance, group size and presence of enteric pathogens early and late in the calving season each farm was visited twice. Calf mortality was not associated with either herd size, space allowance per calf or post-colostrum feeding practices. Higher calf mortality was identified among herds which reported experiencing an on-set of calf pneumonia during weeks 8 to 10 of the calving season. This study demonstrates that factors associated with calf welfare on commercial Irish dairy farms (e.g. space allowance, mortality rate) are independent of herd size. Some management practices however, such as methods used for treating health issues can affect rates of calf mortality experienced. Calf mortality, for example, was lower in herds which treated diarrhoea cases by administering electrolytes, while continuing to offer milk. Behavioural observations indicate that smaller group sizes could promote expression of positive behaviours, potentially resulting from an overall improvement in welfare. Space allowance per calf was not associated with observed behaviour frequencies. We also identified that similar rates of calf mortality are experienced across herds of different sizes.

The role of vanilloid receptor type 1 (TRPV1) in hyperalgesia related to bovine digital dermatitis

Bovine digital dermatitis is a contagious and chronic disease affecting the digits of dairy cattle worldwide. Tissue degradation may alter ionic channels and further activate vanilloid channels, more specifically the vanilloid receptor type 1 (TRPV1) that can generate and modulate hyperalgesia in cows affected with bovine digital dermatitis. The aim of this pilot study was to identify and quantify TRPV1 channels in dairy cows presenting with different stages of bovine digital dermatitis and compare these data according to the disease evolution and degree of hyperalgesia described in previous studies. Biopsies were taken from 15 lactating Holstein cows (23 lesions), and immunochemistry was performed to identify the number of TRPV1 fibers in the 4 M-stages of digital dermatitis and the control group. This pilot study had 5 experimental groups, M1 (5 samples), M2 (5 samples), M3 (4 samples), M4 (4 samples), and the control group (5 samples), with inclusion criteria was the presence of a bovine digital dermatitis lesion in at least one digit. The pilot results demonstrate an increase in expression of TRPV1 receptors in group M4 in comparison with the other groups. Bovine digital dermatitis may cause an increase in expression of TRPV1 receptors in the chronic stages of the disease, possibly contributing to the hyperalgesia described in affected animals; nevertheless, further research is needed to define this relation.

Cost benefit analysis of automatic lameness detection systems in dairy herds: A dynamic programming approach

Epidemiological data establish that lameness is second only to mastitis as the dairy industry's most prevalent and costly animal welfare issue. Using an automatic lameness detection (ALD) system in which continuous, accurate detection is coupled with proper treatment, is key for reducing economic losses due to lameness. It is reasonable to assume that the cost of lameness would vary with its severity. Therefore, our first objective was to estimate the cost of different lameness severity levels as a function of milk production, lameness risk, conception probability, and treatment cost using a dynamic programming (DP) model. Our second objective was to conduct a cost benefit analysis for ALD systems which can reduce production losses through early detection and treatment of lameness, when compared to visual-detection (VD; i.e., performed by humans) systems. The default production loss parameters for the VD system used as inputs to the DP model were either sourced from the literature or were estimated based on data from a field trial. The production loss parameters for the ALD system used as inputs to the DP model were based on extrapolations of parameter values used for the VD system. The profit per present cow per year under assumed expenses and revenues decreased from $426.05 (when lameness incidence was assumed to be 0%) to $389.69 when lameness incidence was 19.5 %. Out of the 19.5 % lameness incidence in our default scenario, 9.8 % were moderate cases and 9.7 % were severe cases. Average cost of lameness was $36.36 at 19.5 % incidence. Average cost of lameness increased with increased incidence and was respectively $82.05, $195.05, and $286.87 at the low, medium, and high incidence scenarios. We used an operational framework which compared the lameness costs between the VD and ALD systems with 25 %, 50 % and 75 % net avoided costs (NAC) for the 10 year lifespan of the ALD system, at default, low, medium and high lameness incidence scenarios. The net return per cow per year from using an ALD system over a VD system was $13, at low incidence and 25 % NAC. The net return per cow per year for the ALD system was as high as $99 at high incidence and 75 % NAC. Out of 351 (3 system prices, 3 system efficiencies, 3 levels of lameness incidence and 13 different herd sizes) scenarios tested, 295 resulted in a net profit within the system lifespan of 10 years, thus justifying the investment in ALD systems.

Chronic Inflammatory Lameness Increases Cytokine Concentration in the Spinal Cord of Dairy Cows

Lameness in dairy cows is an extremely painful multifactorial condition that affects the welfare of animals and economically impacts the dairy industry worldwide. The aim of this study was to determine the profile of cytokines in the spinal cord dorsal horn of dairy cows with painful chronic inflammatory lameness. Concentrations of 10 cytokines were measured in the spinal cord of seven adult dairy cows with chronic lameness and seven adult dairy cows with no lameness. In all cows lameness was evaluated using a mobility scoring system and registered accordingly. Immediately after euthanasia the spinal cord was removed and 20 cm of lumbar segments (L2–L5) were obtained. After dorsal horn removal and processing, cytokine quantification of tumor necrosis factor-alpha (TNF-α), interleukin-1alpha (IL-1α), interleukin 13 (IL-13), chemokine-10 (CXCL10/IP-10), chemokine-9 (CXCL9/MIG), interferon-alpha (IFN-α), interferon-gamma (IFN-γ), interleukin-21 (IL-21), interleukin-36ra (IL-36ra), and macrophage inflammatory protein-1 beta (MIP-1β) was performed using a multiplex array. Lame cows had higher concentrations of TNF-α, IL-1-α, IL-13, CXCL10, CXCL9, IFN-α, and IFN-γ in their dorsal horn compared to non-lame cows, while IL-21 concentration was decreased. No differences in IL-36ra and MIP-1β concentrations between lame and non-lame cows were observed. Painful chronic inflammation of the hoof in dairy cows leads to a marked increase in cytokine concentration in the dorsal horn of the spinal cord, which could represent a state of neuroinflammation of the Central Nervous System (CNS).

The Development of a Hoof Conformation Assessment for Use in Dairy Goats

The assessment of hoof conformation is important due to its recognized relationship with the biomechanical functionality of the hoof. Hoof conformation can be assessed using objective measures or subjective scores. However, to date, there are limited data using either method in dairy goats. Therefore, the aims were to (1) develop a reliable method of assessing hoof conformation in dairy goats, and (2) compare two aspects of a subjective assessment against corresponding objective measures as a means of validation. A total of 1035 goats contributed photographs across 16 commercial dairy goat farms. Photographs were taken of the left front and left hind hoof in the lateral and dorsal aspect at five assessments across the goats' first two lactations. Hoof conformation was assessed using five subjective scores (toe length, heel shape, fetlock shape, claw splay, and claw shape) and two objective measures (toe length ratio and claw splay distance). Following the training of two observers, high levels of inter and intra-reliability were achieved for both the subjective scores (>0.8 weighted kappa) and objective measures (>0.8 Lin's concordance correlation coefficient). Two aspects of the subjectively assessed ordinal scores were compared with the objective measures with high levels of accuracy (>0.8). This suggests that the subjective scores may be a suitable alternative to more time-consuming objective measures when assessment is completed using photographs.

Aetiology, Risk Factors, Diagnosis and Control of Foot-Related Lameness in Dairy Sheep

During the last twenty years, considerable research efforts have recognized the consequences of foot-related lameness primarily in cattle, and meat and wool sheep. Despite the lack of extensive epidemiological studies, field observations and isolated research reports in dairy sheep have suggested that the problem might be more severe in semi-intensive and intensive farming systems. Footrot, contagious ovine digital dermatitis, ovine interdigital dermatitis, white line disease, and pedal joint abscess are the most common causes of foot-related lameness. Dichelobacter nodosus, Fusobacterium necrophorum, Treponema spp., and Actinomyces pyogenes are the most significant foot-related lameness-associated pathogens. Despite a documented hereditary predisposition, environmental factors are the most important in determining the occurrence of foot-related lameness. Moist and warm environment, increased parity and milk yield, inappropriate housing conditions and infrastructures, inadequate hygiene status, imbalanced nutrition, and insufficient foot care are the most critical risk factors. Furthermore, a foot-lameness control plan should include targeted implementation of claw trimming and footbathing, evidence-based planning of hygiene measures in preventive veterinary practices (i.e., antibiotic administration, vaccinations against footrot), selective breeding to footrot resistance, and, most importantly, the continuous training of farming personnel. Controlling foot-lameness in dairy sheep is critical in determining the well-being of animals, and strongly affects the farm's profitability and sustainability.

A longitudinal study of digital cushion thickness and its function as a predictor for compromised locomotion and hoof lesions in Holstein cows

Lameness is a major animal welfare and economic issue for the dairy industry and is a challenge to overcome due to multifaceted causes. Digital cushion thickness (DCT) is a strong predictor of lameness and is phenotypically associated with incidence of claw horn disruption lesions (CHDL; sole ulcers and white line disease). We hypothesized that DCT varies between digits and across lactation within the cow. This variation could be characterized to predict the occurrence of CHDL or compromised locomotion. BCS, visual locomotion score (VLS), DCT, and presence or absence of lesions were collected at 4 time points: <40 d prepartum (DPP), 1 to 30 d in milk (DIM), 90 to 120 DIM, and ≥255 DIM for 183 commercial Holstein cows enrolled in the study. Cows underwent digital sonographic examination for the measurement of DCT evaluated at the typical sole ulcer site beneath the flexor tuberosity for the right front medial and lateral digits and right hind medial and lateral digits. Factors such as parity number and stage in lactation were obtained from farm management software (DairyComp 305; Valley Agricultural Software, Tulare, CA). Cows were grouped by parity: primiparous (parity = 1) or multiparous (parity ≥ 2). The prevalence of CHDL among time points ranged from 0% to 4.2% for primiparous cows vs. 2.5% to 25% for multiparous cows, whereas the prevalence of lameness based on VLS of 3 to 5 ranged from 1.7% to 8.3% for primiparous cows vs. 12.7% to 33% for multiparous cows. DCT varied within primiparous and multiparous cows based on stage of lactation and digit (P < 0.05) and was thicker for both parity groups prior to dry off (≥255 DIM) and thinnest prior to calving (<40 DPP) and after peak lactation (90 to 120 DIM). The DCT of the front medial digit was thickest for primiparous heifers, whereas the hind lateral digit was thickest for multiparous cows. The DCT of the hind medial digit was thinnest for both parity groups. Parity group and DCT of the hind lateral digit <40 DPP were important predictors of CHDL (P < 0.05), whereas parity group and DCT of the hind lateral digit and front lateral digit at 1 to 30 DIM were key predictors of VLS lameness (P < 0.05). These results may help identify animals with higher odds of developing these diseases by highlighting key time points and specific digits of importance for monitoring. In addition, it improves our biological understanding of the relationship between DCT and lameness.

Immunomodulation by Processed Animal Feed: The Role of Maillard Reaction Products and Advanced Glycation End-Products (AGEs)

The immune system provides host protection to infection with pathogenic organisms, while at the same time providing tolerance upon exposure to harmless antigens. Thus, an impaired immune function is associated with increased susceptibility to infections with increased disease severity and thereby necessitating the therapeutic use of antibiotics. Livestock performance and feed efficiency, in addition to their health status, are dependent on the microbial load of their gut, the barrier function of the intestinal epithelium and the activity of the mucosal immune system, all of which can be modulated by dietary components. The majority of feeds that are consumed in pets and livestock have been processed. Processing promotes a non-enzymatic reaction between proteins and sugars called Maillard reaction (MR). Maillard reaction products (MRPs) and advanced Maillard reaction products (AGEs) determine taste, smell, and color of many food products therefore the MR is highly relevant for the feed industry. MRPs interact with different types of immune receptors, including the receptor for advanced glycation end products (RAGE) and immunomodulatory potential of feed proteins can be modified by Maillard reaction. This MR has become an important concern since MRPs/AGEs have been shown to contribute to increasing prevalence of diet-related chronic inflammatory states in the gut with negative health consequences and performance. The immunomodulatory effects of dietary MRPs and AGEs in livestock and pet animals are far less well-described, but widely considered to be similar to the relevant concepts and mechanisms obtained in the human field. This review will highlight immunological mechanisms underlying initiation of the innate and adaptive immune responses by MRPs/AGEs present in animal feeds, which are currently not completely understood. Bridging this knowledge gap, and taking advantage of progress in the human field, will significantly improve nutritional quality of feed and increase the prevention of diet-mediated inflammation in animals.

Relação entre escore de condição corporal e escore de locomoção em vacas leiteiras submetidas a manejo semiextensivo de alimentação

RESUMO Métodos observacionais subjetivos, como escore de locomoção (EL) e escore de condição corporal (ECC), têm sido amplamente utilizados para avaliação populacional de diferentes graus de claudicação e estado nutricional em bovinos. Este estudo objetivou verificar a associação longitudinal entre o escore de condição corporal e o escore de locomoção em vacas da raça Holandesa submetidas a um regime alimentar semiextensivo. O período experimental compreendeu dois anos de observações, em uma propriedade localizada no sul do Rio Grande do Sul. O grupo experimental foi constituído por 900 vacas lactantes, que foram avaliadas trimestralmente por dinâmica ortopédica pelo EL e do estado metabólico pelo ECC. A coleta desses dados foi realizada por três veterinários treinados. A fim de se verificar a correlação entre variáveis, utilizou-se o programa SAS, por meio do método de correlação de Pearson, para determinar a associação entre as variáveis avaliadas (EL e ECC), com nível de significância de 5%. A distribuição dos diferentes escores de locomoção durante o período foi a seguinte: 57,2% dos animais tiveram o escore de locomoção 1, ou seja, estavam saudáveis em relação ao sistema locomotor. O restante dos animais que apresentou algum grau de dificuldade de locomoção distribuiu-se da seguinte forma, segundo a intensidade: 21,6% dos animais apresentaram EL2, 15,5% deles EL3, 3,5% deles EL4 e 2,2% deles EL5. Quanto ao resultado da correlação, observou-se associação negativa (r= -0,57) entre ECC e EL (P= 0,03), com ECC médio de 2,97±0,33 e EL de 1,35±0,24 durante o período experimental. Portanto, há uma correlação negativa entre o escore de condição corporal e o escore de locomoção em vacas da raça Holandesa submetidas ao regime alimentar semiextensivo.

A 100-Year Review: Identification and genetic selection of economically important traits in dairy cattle

Over the past 100 yr, the range of traits considered for genetic selection in dairy cattle populations has progressed to meet the demands of both industry and society. At the turn of the 20th century, dairy farmers were interested in increasing milk production; however, a systematic strategy for selection was not available. Organized milk performance recording took shape, followed quickly by conformation scoring. Methodological advances in both genetic theory and statistics around the middle of the century, together with technological innovations in computing, paved the way for powerful multitrait analyses. As more sophisticated analytical techniques for traits were developed and incorporated into selection programs, production began to increase rapidly, and the wheels of genetic progress began to turn. By the end of the century, the focus of selection had moved away from being purely production oriented toward a more balanced breeding goal. This shift occurred partly due to increasing health and fertility issues and partly due to societal pressure and welfare concerns. Traits encompassing longevity, fertility, calving, health, and workability have now been integrated into selection indices. Current research focuses on fitness, health, welfare, milk quality, and environmental sustainability, underlying the concentrated emphasis on a more comprehensive breeding goal. In the future, on-farm sensors, data loggers, precision measurement techniques, and other technological aids will provide even more data for use in selection, and the difficulty will lie not in measuring phenotypes but rather in choosing which traits to select for.

A comparison of a novel time-based summary measure of dairy cow health against cumulative disease frequency

Background

There is an increasing push for dairy production to be scientifically grounded and ethically responsible in the oversight of animal health and well-being. Addressing underlying challenges affecting the quality and length of productive life necessitates novel assessment and accountability metrics. Human medical epidemiologists developed the Disability-Adjusted Life Year metric as a summary measure of health addressing the complementary nature of disease and death. The goal of this project was to develop and implement a dairy Disease-Adjusted Lactation (DALact) summary measure of health, as a comparison against cumulative disease frequency.

Methods

A total of 5694 cows were enrolled at freshening from January 1st, 2014 through May 26th, 2015 on 3 similarly managed U.S. Midwestern Plains’ region dairies. Eleven health categories of interest were tracked from enrollment until culling, death, or the study’s completion date. The DALact accounted for the days of life lost due to illness, forced removal, and death relative to the average lactation length across the participating farms.

Results

The DALact consistently identified mastitis as the primary disease of concern on all 3 dairies (19,007–23,955 days lost). Secondary issues included musculoskeletal injuries (19,559 days), pneumonia (11,034 days), or lameness (8858 days). By comparison, cumulative frequency measures pointed to mastitis (31–50%) and lameness (25–54%) as the 2 most frequent diseases. Notably, the DALact provided a robust accounting of health events such as musculoskeletal injuries (5010–19,559 days) and calving trauma (2952–5868 days) otherwise overlooked by frequency measures (0–3%).

Conclusions

The DALact provides a time-based method for assessing the overall burden of disease on dairies. It is important to emphasize that a summary measure of dairy health goes beyond simply linking morbidity to culling and mortality in a standardized fashion. A summary measure speaks to the burden of disease on both the well-being and productivity of individuals and populations. When framed as lost days, years, or lactations the various health issues on a farm are more comprehensible than they may be by frequency measures alone. Such an alternative accounting of disease highlights the lost opportunity costs of production as well as the burden of disease on life as a whole.

Short communication: Detection of lameness in dairy cows using a grooming device

Lameness in dairy cattle is a common welfare problem with significant economic implications. All too often, appropriate treatment is delayed or neglected due to insufficient detection of lame cows. Brush usage is considered a low-resilience activity; that is, one that typically decreases when energy resources are limited or when the cost involved in the activity increases, such as during sickness and stress. The aim of this study was to determine the association between brush usage and different degrees of lameness. Locomotion scores of 209 lactating Holstein dairy cows were collected individually once a week for 14 consecutive weeks, using a 5-point visual assessment scoring system (1 = nonlame, 2 = uneven gait, 3 = mild lameness, 4 = lameness, 5 = severe lameness). Daily brush usage was collected automatically from 3 cowsheds of similar size and structure located on a commercial dairy farm. In each of the 3 cowsheds, 2 brushes were installed, one next to the feed bunk, and the other away from the feed bunk (on the opposite side of the cowshed). Linear and generalized linear mixed-effects models were used to evaluate the association between locomotion scores and daily measures of brush usage. We found a significant interaction between locomotion score and brush location (near to/distant from feed bunk) on the daily proportion of cows using the brush at least once and on daily duration of brush usage. Specifically, we showed that lame and severely lame cows did not use brushes that were installed away from the feed bunk but continued to use brushes that were installed next to the feed bunk. Brush usage by cows with uneven gait (locomotion score 2) or with mild lameness (locomotion score 3) did not differ from that of nonlame cows (locomotion score 1). The results of this study suggest that monitoring of daily usage of brushes located away from the feed bunk could be a useful method for detecting lameness and severe lameness in dairy cows. However, the use of this method to detect mild lameness or cases of abnormal gait is, at this stage, less promising.