Effects of alley and stall surfaces on indices of claw and leg health in dairy cattle housed in a free-stall barn

Invited review: Prevalence, risk factors, treatment, and barriers to best practice adoption for lameness and injuries in dairy cattle-A narrative review

Lameness and leg injuries are both painful and prevalent across the dairy industry, and are a major welfare concern. There has been a considerable amount of research focused on investigating the risk factors associated with lameness and injuries and how they might be prevented and treated. The objectives of this narrative review were to summarize herd-level prevalence estimates, risk factors, strategies for prevention, control, and treatment of these conditions, and the barriers to best practice adoption for lameness and injuries on dairy farms. There is a relatively high within-herd prevalence of lameness on dairy farms globally, with a recent systematic review estimating the mean prevalence at 22.8%. Similarly, there is a relatively high prevalence of hock injuries, with within-herd estimates ranging from 12% to 81% of cows affected. Knee and neck injuries have been reported to be less common, with 6% to 43% and 1% to 33%, respectively. Numerous risk factors have been associated with the incidence of lameness, notably housing (e.g., access to pasture, bedding depth, bedding type, flooring type, stall design), management (e.g., stall cleanliness, frequency of trimming, holding times, stocking density), and cow-level (e.g., body condition, parity, injured hocks) factors. Risk factors associated with hock injuries can be similarly classified into housing (e.g., bedding type and depth, outdoor access, parlor type, stall design), management (e.g., bedding depth, cleanliness), and cow (e.g., parity, days in milk, lameness) factors. Key preventative approaches for lameness include routine preventative and corrective hoof trimming, improving hoof cushioning and traction through access to pasture or adding rubber flooring, deep-bedded stalls, sand bedding, ensuring appropriate stocking densities, reduced holding times, and the frequent use of routine footbaths. Very little research has been conducted on hock, knee, and neck injury prevention and recovery. Numerous researchers have concluded that both extrinsic (e.g., time, money, space) and intrinsic (e.g., farmer attitude, perception, priorities, and mindset) barriers exist to addressing lameness and injuries on dairy farms. There are many diverse stakeholders in lameness and injury management including the farmer, farm staff, veterinarian, hoof trimmer, nutritionist, and other advisors. Addressing dairy cattle lameness and injuries must, therefore, consider the people involved, as it is these people who are influencing and implementing on-farm decisions related to lameness prevention, treatment, and control.

Measuring dairy cow welfare with real-time sensor-based data and farm records: a concept study

Welfare assessment of dairy cows by in-person farm visits provides only a snapshot of welfare and is time-consuming and costly. Possible solutions to reduce the need for in-person assessments would be to exploit sensor data and other routinely collected on-farm records. The aim of this study was to develop an algorithm to classify dairy cow welfare based on sensors (accelerometer and/or milk meter) and farm records (e.g. days in milk, lactation number). In total, 318 cows from six commercial farms located in Finland, Italy and Spain (two farms each) were enrolled for a pilot study lasting 135 days. During this time, cows were routinely scored using 14 animal-based measures of good feeding, health and housing based on the Welfare Quality® (WQ®) protocol. WQ® measures were evaluated daily or approximately every 45 days, using disease treatments from farm records and on-farm visits, respectively. WQ® measures were supplemented with daily temperature-humidity index to account for heat stress. The severity and duration of each welfare measure were evaluated, and the final welfare index was obtained by summing up the values for each cow on each pilot study day, and stratifying the result into three classes: good, moderate and poor welfare. For model building, a machine-learning (ML) algorithm based on gradient-boosted trees (XGBoost) was applied. Two model versions were tested: (1) a global model tested on unseen herd, and (2) a herd-specific model tested on unseen part of the data from the same herd. The version (1) served as an example on the model performance on a herd not previsited by the evaluator, while version (2) resembled a custom-made solution requiring in-person welfare evaluation for model training. Our results indicated that the global model had a low performance with average sensitivity and specificity of 0.44 and 0.68, respectively. For the herd-specific version, the model performance was higher reaching an average of 0.64 sensitivity and 0.80 specificity. The highest classification performance was obtained for cows in poor welfare, followed by cows in good and moderate welfare (balanced accuracy of 0.77, 0.71 and 0.68, respectively). Since the global model had low classification accuracy, the use of the developed model as a stand-alone system based solely on sensor data is infeasible, and a combination of in-person and sensor-based welfare evaluation would be preferable for a reliable welfare assessment. ML-based solutions, even with fair discriminative abilities, have the potential to enhance dairy welfare monitoring.

Evaluation of an Accelerometer-Based Device for Testing the Softness of Bedding Materials Used for Livestock

Lying is a high priority behavior for dairy cows. As the quality of cubicles can influence their lying time, the interest in finding objective methods to assess the quality of floors has increased substantially over recent decades. This study aimed to evaluate a technical device for measuring elastic properties of floors for the application to bedding materials for cows. Ten different floor types were used: horse manure, recycled manure solids, bark mulch, sand, sawdust, and three different rubber mats. Horse manure and bark mulch were additionally tested with chopped straw as a top layer. Two devices of the same kind and two examiners were available for performing comparative measurements. Regression analyses and an ANOVA were conducted to compare the devices, examiners, and different surfaces. Most of the floors differed significantly from each other. Sawdust was the softest material, followed by sand and recycled manure solids. The agreement between the devices (Lin’s concordance correlation coefficient (CCC) > 0.99, Spearman’s rank correlation coefficient (rS) = 0.99) and examiners (CCC = 0.99, rS = 0.99) was almost perfect. These findings indicate that this device can be used as a new method for assessing the softness of bedding materials for dairy cows objectively.

Decision tree analysis to evaluate risks associated with lameness on dairy farms with automated milking systems

Lameness is an endemic disorder causing health problems and production losses in the dairy cow industry. The objective of this study was to identify cow and farm-level factors associated with lameness on Automatic Milking System (AMS) farms, using decision tree analysis to assign probabilities to each input. AMS farms across Canada and Michigan were evaluated to identify the most substantial farm (i.e., stall design, bedding) and cow-level (i.e., BCS, leg injuries) factors associated with prevalence of lameness. To assess lameness, videos of cows were used, and cows with a head bob or noticeable limp were categorized as lame. A decision tree classification model used 1378 data points from 39 pens across 36 farms to predict the value of the target class through “tree function” in MATLAB. The primary classifier was identified as type of stall base, dividing the data set into 3 categories: 1) rubber, sand, or geotextile mat flooring, 2) concrete base, and 3) other types of stall base. Within the first category (class membership (CM) = 976), bedding quantity was the secondary classifier, which was divided by cows standing on ≥2 cm (CM=456) or <2 cm (CM=520) of bedding. Bedding quantity was divided into the third most important classifier of BCS, and cow fit stall width. Cows with BCS of 3.25 to 4.5 (CM=307) were defined as non-lame with an estimated probability (EP) of 0.59, while cows with BCS of 2 to 2.5 (CM=213) were further split by hock lesion incidence. Cows without lesions were defined non-lame (EP=0.93) and cows with lesions were defined lame (EP=0.07). Cows that fit stall width were defined as non-lame (EP=0.66) and cows that did not fit were further divided by the width of the feed alley. Farms with ≥430 cm feed alley were defined as non-lame (EP=0.89), whereas farms with <430 cm feed alley were defined as lame (EP=0.11). Through implementing a novel multifactorial approach of data analysis, we were able to highlight the critical points that can be focused on to enhance farm-level housing and management practices or mitigate or monitor cow-level issues to reduce incidence and severity of lameness in AMS farms.

Why Is the Grass the Best Surface to Prevent Lameness? Integrative Analysis of Functional Ranges as a Key for Dairy Cows’ Welfare

Simple Summary

Lameness is a highly prevalent clinical condition that causes movement disorders in dairy cows worldwide. With an estimated global population of one billion dairy cows, producing 522 million metric tons of milk per year, this problem affects food availability as well as the global economy. While grass is considered to be the best support surface for cattle, in many places it cannot be used, particularly when climate conditions are too harsh for grass to grow or be maintained. In this paper, we investigate whether grass is the best surface to prevent lameness. The answer to this question is fundamental to establishing better farming practices for cattle welfare. We built an integrative analysis of functional ranges to establish the minimum and maximum movement capacities that a cow has, according to the surfaces to which it is subjected in free housing systems. Using this analysis, we identified many aspects that make a grass surface the healthiest option for cattle. However, when grass is not available, this type of strategy can help to find the best characteristics for other possible surfaces. Our study applies movement analysis to one of the most critical problems in the world of livestock management and contributes towards finding the balance between animal welfare and production.

Abstract

Lameness is a painful clinical condition of the bovine locomotor system that results in alterations of movement. Together with mastitis and infertility, lameness is the main welfare, health, and production problem found in intensive dairy farms worldwide. The clinical assessment of lameness results in an imprecise diagnosis and delayed intervention. Hence, the current approach to the problem is palliative rather than preventive. The five main surfaces used in free housing systems in dairy farms are two natural (grass and sand) and three artificial (rubber, asphalt, and concrete). Each surface presents a different risk potential for lameness, with grass carrying the lowest threat. The aim of the present study is to evaluate the flooring type influences on cows’ movement capabilities, using all the available information relating to kinematics, kinetics, behavior, and posture in free-housed dairy cows. Inspired by a refurbished movement ecology concept, we conducted a literature review, taking into account kinematics, kinetics, behavior, and posture parameters by reference to the main surfaces used in free housing systems for dairy cows. We built an integrative analysis of functional ranges (IAFuR), which provides a combined welfare status diagram for the optimal (i.e., within the upper and lower limit) functional ranges for movement (i.e., posture, kinematics, and kinetics), navigation (i.e., behavior), and recovery capacities (i.e., metabolic cost). Our analysis confirms grass’ outstanding clinical performance, as well as for all of the movement parameters measured. Grass boosts pedal joint homeostasis; provides reliable, safe, and costless locomotion; promotes longer resting times. Sand is the best natural alternative surface, but it presents an elevated metabolic cost. Rubber is an acceptable artificial alternative surface, but it is important to consider the mechanical and design properties. Asphalt and concrete surfaces are the most harmful because of the high traffic abrasiveness and loading impact. Furthermore, IAFuR can be used to consider other qualitative and quantitative parameters and to provide recommendations on material properties and the design of any surface, so as to move towards a more grass-like feel. We also suggest the implementation of a decision-making pathway to facilitate the interpretation of movement data in a more comprehensive way, in order to promote consistent, adaptable, timely, and adequate management decisions.

Impacts of drainage beds covered with sand and wood shavings on the comfort behaviour of dairy buffalo in a temperate climate

Background

Comfortable beds play an important role in increasing the ruminant and milk production efficiency of dairy buffalo. In loose housing systems, cow lying comfort depends on both the bedding materials and bed base.

Results

Buffaloes spent more lying time on sand beds at depth of 15 and 20 cm (S-15 and S-20) than on beds of 10 cm (S-10a) beds or in the feed alley in Exp1 (P < 0.01). No significant difference in the cow comfort index (CCI) was detected between S-10a and S-15; however, both showed higher CCI than that of the S-20 bed. In Exp2, buffaloes spent more time lying on the wood shavings at depth of 15 cm (WS-15) bed followed by the WS-20 and S-10b beds, respectively (P < 0.01), and CCI was greater in the WS-15 bed than in the S-10b and WS-20 beds (P < 0.05).

Conclusion

A depth of sand or wood shavings at 15 cm can meet the lying comfort requirements of dairy buffaloes when bedding materials are used above drainage beds.

Impacts of Compost Bedded Pack Barns on the Welfare and Comfort of Dairy Cows

Simple Summary

As few studies have examined the most common housing systems in terms of cow behavior and welfare, we designed this study to compare three loose housing systems for lactating cows: compost bedded pack, conventional bedded pack, and freestalls. Cows kept in bedded pack barns were dirtier yet had fewer hairless patches and lesions or swellings on the body and spent more time lying down in the resting area than cows housed in freestalls. All housing systems show benefits and inconveniences in terms of welfare and comfort at resting. Other factors, such as management practices and proper barn design, should be considered when comparing housing systems in terms of animal welfare.

Abstract

Three loose housing systems for lactating cows (compost bedded pack, CBP; conventional bedded pack, BP; and freestalls, FS) were assessed on one farm in terms of cow behavior and welfare. An on-farm welfare assessment based on the Welfare Quality protocols was used four times every three months on 757 cows. Video recordings taken twice over four days were used to assess behavior patterns at resting areas. Cows in CBP and BP were dirtier than those in FS (p < 0.0001). Fewer integument alterations were recorded for CBP and BP than FS (p < 0.001). Cows in BP were quicker to lie down and stand up compared to those in CBP or FS (p < 0.001). Percentages of cows needing more attempts before rising were higher for FS (p < 0.01). However, a higher frequency of kneeling was observed in CBP (p = 0.033). A lower percentage of cows lying in the resting area was recorded for FS (56%) than CBP or BP (97 or 84%, respectively, p < 0.05). Overall, in this study, cows kept in bedded pack barns were dirtier but had fewer integument alterations and spent more time lying down in the resting area than cows housed in freestalls.

Kinetic effect of different ground conditions on the sole of the claws of standing and walking dairy cows

For the first time, we analyzed the direct kinetic effects of concrete and rubber flooring on the soles of live dairy cows' claws while standing and walking. Ten adult dairy cows were equipped with foil-based pressure sensors (HoofSystem, Tekscan Inc., Boston, MA) under their left hind leg using a leather claw shoe. These sensors captured parameters of pressure distribution and vertical ground reaction forces while the cows walked on the 2 tested flooring types. The mean pressure was 15.1 to 21.1% lower on rubber flooring compared with concrete; mean pressure values (± standard deviation) were 36.32 ± 7.77 N/cm² for static measures and 57.33 ± 11.77 N/cm² for dynamic measures. We observed an even more obvious relief on rubber flooring in the maximum pressure loads, which were 30.1 to 32.7% lower on rubber flooring compared with concrete; mean pressure values (± standard deviation) were 98.79 ± 14.49 N/cm² for static measures and 150.45 ± 20.87 N/cm² for dynamic measures). The force-time curves of the dynamic measures essentially showed biphasic curve progression, with local peaks at 29 and 79% of the stance phase. However, we found considerable differences in curve progression between individuals and between the lateral and medial claws, which may be verified in further investigations with more animals. The study showed a noticeable reduction in mechanical load during standing and walking on rubber flooring compared with concrete.

Does the range of motion in the bovine interphalangeal joints change with flooring condition? A pilot study using biplane high-speed fluoroscopic kinematography

This study had 2 objectives. The first objective was to investigate motion patterns and the range of motion of the bovine proximal and distal interphalangeal joints on concrete during the stance phase. The second objective was to determine whether the range of motion and the locomotive stability of the interphalangeal joints differ on concrete and 3 different commercially available rubber mats (Karera, Kura, and Pedikura; Kraiburg Elastik GmbH & Co. KG, Tittmoning, Germany). Biplane high-speed fluoroscopic kinematography (72 ± 2.5 kV and 112.5 ± 12.5 mA, refresh rate 500 frames per second, shutter 0.5 ms) was applied to record 1 stance phase of the right forelimb of 2 Holstein Friesian heifers (15 mo old, 440 ± 10 kg; ± standard deviation) on each flooring. Three-dimensional digital animations were generated with a marker-supported manual animation technique based on the recordings and computer tomographic bone models. The mean maximum range of motion of each of the 4 interphalangeal joints in terms of flexion/extension, abduction/adduction, and internal/external rotation were calculated as well as the mean number of local extrema as a measure of stability during the stance phase. The main degree of freedom in all interphalangeal joints was flexion and extension with a range of motion of 17.7 to 25.9°. The second largest degree of freedom differed between abduction/adduction (7.7-10.0°) and internal/external rotation (6.5-9.6°) depending on the joint. Remarkably, although smaller, these extrasagittal directions still contribute to the overall motion to a considerable degree. In addition, the interphalangeal joints of the lateral digit showed a tendency to move less during the stance phase than their medial counterparts. Comparing concrete to the rubber mats, the interphalangeal joints tend to have to cover a larger range of motion on concrete with the exception of the distal interphalangeal joint in terms of flexion/extension. The unyielding surface of concrete seems to force the flexible parts of the animal-ground-interaction into extended motion. Furthermore, there tends to be more instability in all 3 degrees of freedom in all 4 joints on concrete, implying a greater effort of the soft tissues to achieve a balanced motion. Detailed biomechanical research contributes to the development of adequate flooring systems by evaluating the mechanical strain on claws and joints and working toward lameness prevention and thus animal welfare.

Effect of different flooring types on pressure distribution under the bovine claw - an ex vivo study

BACKGROUND

Mechanical interactions between hard floorings and the sole of bovine claws can be reasonable to cause traumatic claw lesions. In this ex vivo study, the direct kinetic impact of concrete and three types of rubber mats on the sole of dairy cattle claws was analyzed. In order to apply uniform loads, isolated distal hind limbs of adult Holstein Friesian dairy cows were functionally trimmed according to the Dutch method and attached to a load applicator. Kinetic data were recorded using a thin, foil-based pressure measurement system (Hoof™ System, Tekscan®).

RESULTS

On concrete, the load distribution between the lateral and medial claw was less balanced than on the rubber floorings. The loaded area was significantly smaller on concrete (32.2 cm2) compared to all rubber mats (48.3-58.0 cm2). Average pressures (Pav) and maximum pressures (Pmax) were significantly higher on concrete (Pav 44.7 N/cm2; Pmax 130.3 N/cm2) compared to the rubber floorings (Pav 24.9-29.7 N/cm2; Pmax 71.9-87.2 N/cm2). Pressure peaks occurred mainly in plantar and abaxial parts of the lateral claw and in apical and plantar regions of the medial claw. Load distribution displayed a widely unloaded slope region, but considering the pressure distribution under the claw, none of the zones showed a generally lower pressure exposure.

CONCLUSIONS

Altogether, rubber floorings lead to a significant mechanical relief of the sole compared to concrete. Furthermore, relevant differences between the tested rubber mats could be determined. Therefore the used system may be applied to compare further flooring types.

A Review of the Relationship Between Hoof Trimming and Dairy Cattle Welfare

A narrative integrative review on the evidence for hoof trimming found 16 articles on efficacy, frequency, and associations with behavior and physiologic parameters. Review of these studies revealed (1) hoof trimming is associated with behavior and physiologic changes; (2) increasing the frequency of hoof trimming seems to decrease the incidence of hoof lesions; (3) there is limited research to support any particular technique; and (4) descriptions of the hoof trimming techniques used is inadequate in most articles. To increase scientific support for hoof trimming practices, current knowledge gaps in technique, timing, and frequency of hoof trimming need to be addressed.

Does floor surface affect locomotion behaviour of crossbred cows under loose housing system?

Present study was conducted to evaluate the effect of floor surface on lameness score and walking speed of crossbred cows under loose housing system. Crossbred cows (24) were selected and randomly assigned into one of the four groups (6 in each group) having different combination of flooring surface viz. T0-Concrete floor (in covered feeding area) + Brick paved (in open area), T1-Concrete (in covered feeding area) + Sand bed (in open area), T2- Rubber mat (in covered feeding area) + Sand bed (in open area) and T3- Rubber mat (in covered feeding area) + Brick paved (in open area). All experimental animals were scored for lameness using “Visual Lameness Scoring” (VLS) system on 1-5 scale. Walking speed of cows was also observed during experimental period. Lameness scores were significantly different between the groups. Lameness score were greater for cow housed in T3 and T0 group. However, lameness score were lower in cows housed in T1 and T2 group. Walking speed differed significantly between treatments and was greater in T2 and T1 than T3 and T0. Cow housed in T0 and T3 group walked slower compared to T1 and T2 group. Further, proportionally greater numbers of cows with higher lameness score were found in T0 and T3 group. It can be concluded that equipping open area with sand bed with either concrete or rubber mat in covered area improved animal welfare in term of decreasing lameness. While providing rubber mat alone with brick was comparable to concrete and brick.

Influence of Soft or Hard Floors before and after First Calving on Dairy Heifer Locomotion, Claw and Leg Health

Simple Summary

In this study the effect of different flooring systems on locomotion, claw conformation, loading, claw- and leg disorders was assessed in heifers from one year before to one year after calving. After calving, heifers kept on alleys covered with rubber flooring were found to develop less lameness, fewer claw disorders of the sole horn and fewer leg lesions than those kept on concrete alleys. Recruitment heifers reared on soft deep straw bedding had fewer sole horn lesions and more overgrown claws before calving, but were more prone to severe sole horn lesions after calving, than those reared in cubicles with hard concrete floors.

Abstract

Claw health, an important dairy cow welfare parameter, may be affected by early-life foot/leg stresses. To investigate this, groups of pregnant heifers were allocated to deep straw bedding (Soft) or cubicles (Hard), both with scraped concrete feeding alleys. After the grazing season, they were re-housed in cubicle systems, half on slatted concrete (Hard) and half on slatted rubber (Soft) alleys. Claw measurements, contact area and pressure distribution claw/flooring, claw disorders and leg lesions were recorded at the start and end of each housing season. Locomotion and leg lesions were also scored monthly after calving. Prevalence of sole haemorrhages was higher among pregnant heifers in cubicles than in deep straw. After calving, first-calvers on Hard floors had higher odds for lameness (OR = 3.6; p < 0.01), sole haemorrhages/ulcers (OR = 2.2; p < 0.05), white-line haemorrhages (OR = 2.8; p < 0.01) and leg lesions (OR = 2.6; p < 0.02) than those on Soft floors. Lowest prevalence and severity of sole and white-line haemorrhages (non-significant) in first-calvers was found in those on Soft floors and reared on Hard floors and the highest prevalence and severity on those on Hard floors reared on Soft floors. Soft flooring after calving is of most importance for healthy feet and legs.

Effect of routine claw trimming on claw temperature in dairy cows measured by infrared thermography

Infrared thermography (IRT) was used to assess the effect of routine claw trimming on claw temperature. In total, 648 IRT observations each were collected from 81 cows housed in 6 tiestalls before and 3 wk after claw trimming. The feet were classified as either healthy (nonlesion group, n = 182) or affected with infectious foot disorders (group IFD, n = 142). The maximal surface temperatures of the coronary band and skin and the difference of the maximal temperatures (ΔT) between the lateral and medial claws of the respective foot were assessed. Linear mixed models, correcting for the hierarchical structure of the data, ambient temperature, and infectious status of the claws, were developed to evaluate the effect of time in relation to the trimming event (d 0 versus d 21) and claw (medial versus lateral). Front feet and hind feet were analyzed separately. Ambient temperature and infectious foot status were identified as external and internal factors, respectively, that significantly affected claw temperature. Before claw trimming, the lateral claws of the hind feet were significantly warmer compared with the medial claws, whereas such a difference was not evident for the claws of the front feet. At d 21, ΔT of the hind feet was reduced by ≥ 0.25 °C, whereas it was increased by ≤ 0.13 °C in the front feet compared with d 0. Therefore, trimming was associated with a remarkable decrease of ΔT of the hind claws. Equalizing the weight bearing of the hind feet by routine claw trimming is associated with a measurable reduction of ΔT between the paired hind claws.

Dynamics and impact of footrot and climate on hoof horn length in 50 ewes from one farm over a period of 10 months

Footrot, including interdigital dermatitis, is caused by Dichelobacter nodosus cause the majority of lameness in sheep in the UK. Lame sheep often have overgrown hoof horn but recent evidence has indicated that trimming overgrown hoof horn increases recovery time, and that routine foot trimming of the flock does not reduce the prevalence or incidence of lameness. The objectives of this study were to investigate the temporal associations between hoof horn length, footrot and climate. Fifty multiparous ewes were monitored for 10 months. On eight occasions hoof horn length, foot lesions and body condition were recorded. At the first examination, ewes were assigned to one of two treatment groups. All ewes that became lame with footrot were treated at one time point per week, either by trimming hoof horn and applying a topical antibiotic spray or with parenteral antibiotic and topical antibiotic spray.

Hoof horn length in ewes at pasture varied over the year and was associated with temperature and rainfall. New cases of footrot occurred all year round and were associated with prior prevalence of footrot in the flock and prior temperature and rainfall. Overgrown hoof horn did not precede lameness but occurred once the sheep were lame. One year of prompt treatment of footrot reduced the range in hoof horn length in the sheep in both treatment groups. At the end of the study the hoof lengths of ewes in both groups were not significantly different. On this farm, hoof horn length was self-regulating in both non-lame and treated lame sheep whether trimming was part of the treatment or not and there would have been no benefit from routine foot trimming of this flock.

Hock lesion epidemiology in cubicle housed dairy cows across two breeds, farming systems and countries

This cross-sectional study examined various aspects of cubicle design and management in terms of their potential as risk factors for hock lesions, using an epidemiological approach. Cubicle dairy farms in Germany and Austria with Holstein Friesian or Simmental cows were visited during the winter housing season. 105 farms and 3691 cows were included in the analysis which consisted of three steps: bifactorial regression, regression trees and multiple linear regression. The mean farm prevalence of hock lesions, i.e. scabs, wounds, and swellings was 50%, with a range from 0 to 100%. The final model contained eight factors which were largely related to lying comfort and explained 75% of the variance. The presence of a curb turned out to be the most influential beneficial factor. Additionally, there were fewer hock lesions when cows were housed with deep bedded cubicles compared to cubicles without deep bedding. Other factors in the regression model were softness and length of the lying surface and height of free space under cubicle partitions, the proportion of overconditioned cows and a variable encoding three different combinations of region, husbandry system (organic and conventional) and breed. Independently from the risk factor model hock lesions were positively correlated with lameness at herd level as well as at animal level. This probably results from related risk factors for both conditions. It can be concluded that lying comfort of dairy cows should be improved in order to prevent hock lesions. In addition, preventive measures for hock lesions at the same time have a potential of reducing lameness and thus to improve cow welfare in several aspects.

A study on cow comfort and risk for lameness and mastitis in relation to different types of bedding materials

The aim was to obtain data regarding the effects of 4 freestall bedding materials (i.e., box compost, sand, horse manure, and foam mattresses) on cow comfort and risks for lameness and mastitis. The comfort of freestalls was measured by analyzing the way cows entered the stalls, the duration and smoothness of the descent movement, and the duration of the lying bout. The cleanliness of the cows was evaluated on 3 different body parts: (1) udder, (2) flank, and (3) lower rear legs, and the bacteriological counts of the bedding materials were determined. The combination of the cleanliness of the cows and the bacteriological count of the bedding material provided an estimate of the risk to which dairy cows are exposed in terms of intramammary infections. The results of the hock assessment revealed that the percentage of cows with healthy hocks was lower (20.5 ± 6.7), the percentage of cows with both damaged and swollen hocks was higher (26.8 ± 3.2), and the severity of the damaged hock was higher (2.32 ± 0.17) on farms using foam mattresses compared with deep litter materials [i.e., box compost (64.0 ± 10.4, 3.5 ± 4.7, 1.85 ± 0.23, respectively), sand (54.6 ± 8.2, 2.0 ± 2.8, 1.91 ± 0.09, respectively), and horse manure (54.6 ± 4.5, 5.5 ± 5.4, 1.85 ± 0.17, respectively)]. In addition, cows needed more time to lie down (140.2 ± 84.2s) on farms using foam mattresses compared with the deep litter materials sand and horse manure (sand: 50.1 ± 31.6s, horse manure: 32.9 ± 0.8s). Furthermore, the duration of the lying bout was shorter (47.9 ± 7.4 min) on farms using foam mattresses compared to sand (92.0 ± 12.9 min). These results indicate that deep litter materials provide a more comfortable lying surface compared with foam mattresses. The 3 deep litter bedding materials differed in relation to each other in terms of comfort and their estimate of risk to which cows were exposed in terms of intramammary infections [box compost: 17.8 cfu (1.0(4)) ± 19.4/g; sand: 1.2 cfu (1.0(4)) ± 1.6/g; horse manure: 110.5 cfu (1.0(4)) ± 86.3/g]. Box compost had a low gram-negative bacterial count compared with horse manure, and was associated with less hock injury compared with foam mattresses, but did not improve lying behavior (lying descent duration: 75.6 ± 38.8s, lying bout duration: 46.1 ± 18.5 min). Overall, sand provided the best results, with a comfortable lying surface and a low bacterial count.

Changes in hoof health and animal hygiene in a dairy herd after covering concrete slatted floor with slatted rubber mats: a case study

The objective was to investigate the effect of changing the flooring in the alleys of a barn from slatted concrete to slatted rubber mats on hoof disorders and animal hygiene in 44 loose-housed Brown Swiss dairy cows. Cows were examined for disorders of the hind hooves (hemorrhages, white line fissures, ulcers, heel horn erosion, and digital dermatitis) and for skin lesions. The dirtiness of the animals and of the floor was recorded. Climatic (temperature, humidity) and ammonia gas conditions were measured. Evaluations were carried out when the cows were housed on a concrete slatted floor and after 4 and 10 mo on soft flooring (slatted rubber mats, 29-mm thick). The anatomical portion of claw (medial, lateral), number of lactations (parity), and days in milk were included as covariates in the statistical model. Changing the flooring from slatted concrete to slatted rubber mats increased the score for white line fissures [1.0 ± 0.3 (concrete) vs. 2.5 ± 0.4 (10 mo rubber mats)] and influenced air humidity (i.e., the difference in the absolute humidity between the inside and outside of the barn increased from 1.5 ± 0.1 to 1.7 ± 0.2g/m(3)), whereas the other hoof disorders, skin lesions (score of 8.7 ± 0.3), the dirtiness of the animals (score of 5.9 ± 0.3), and the floor (score of 2.1 ± 0.1), and ammonia gas concentration (2.6 ± 0.3mg/kg) were not affected (overall scores or measures; mean ± SE). Lateral claws were more affected (except for heel horn erosion) than medial claws (estimated effects between 1.3 ± 0.2 and 3.0 ± 0.6). Parity influenced hoof disorders (except for hemorrhages) and skin lesions (estimated effects between -0.6 ± 0.3 and 0.5 ± 0.2). Days in milk influenced hoof disorders, but had no effect on skin lesions and on the dirtiness of the animal. Irrespective of floor type, the slots (2.6 ± 0.1) were dirtier than the slats (1.6 ± 0.1). In conclusion, covering slatted concrete flooring with slatted rubber mats partially impaired hoof health but did not influence skin lesions or the dirtiness of the cows or the floor. Similar results were found for climatic conditions, as ammonia gas concentration was not affected, but absolute humidity increased in the barn when rubber mats were present.

Soil versus Pond Ash Surfacing of Feedlot Pens: Occurrence of Escherichia coli O157:H7 in Cattle and Persistence in Manure

Reducing Escherichia coli O157:H7 in cattle and their manure is critical for reducing the risk for human foodborne and waterborne illness. The objective of this study was to evaluate the effects of soil and pond ash surfaces for feedlot pens on the prevalence, levels, and/or persistence of naturally occurring E. coli O157:H7 and total E. coli in cattle (feces and hides) and manure. Cattle (128 beef heifers) were sorted among 16 pens: 8 surfaced with soil and 8 surfaced with pond ash. The prevalence of E. coli O157:H7 in feces decreased (P < 0.0001) during the study from 57.0% on day 0 to 3.9% on day 84 but did not differ (P > or = 0.05) between cattle on soil and on pond ash pens at any sampling period. The prevalence of the pathogen on hides and in feedlot surface material (FSM) also decreased (P < 0.0001), with no effect of soil or pond ash surface (P > or = 0.05). Similarly, levels of E. coli in FSM did not differ (P > or = 0.05) at any sampling period, and there were no clear trends for survival differences of E. coli O157:H7 or E. coli in FSM between pond ash and soil surfaces, although E. coli populations survived at 5.0 log CFU/g of FSM on the pen surfaces 6 weeks after the cattle were removed. These results indicate that housing cattle on pens surfaced with pond ash versus pens surfaced with soil does not affect E. coli O157:H7 in cattle or their manure.

COWEL: a decision support system to assess welfare of husbandry systems for dairy cattle

Animals have various behavioural and physiological needs that are important for welfare. Fulfilment of these needs depends on the quality of housing, management and animal characteristics. The objective of this study was to develop a model to assign welfare scores to husbandry systems for dairy cattle, based on scientific results, and thereby supporting the design of new, welfare-friendly systems. COWEL is a computer-based decision support system that contains attributes regarding housing and management conditions. These attributes are technical specifications that contain various technical units called levels. These levels are ranked from best-to-worst regarding welfare, based on scientific information about animal-based parameters. This information, inserted in the model as statements, was weighted depending on the impact it has on welfare by using weighting categories. Thereafter, a weighting factor was calculated for each attribute which determines how important an attribute is for welfare. The COWEL model contains 2,343 statements on dairy cattle welfare from 476 sources found during a literature survey. The model was applied to four husbandry systems, namely a tie-stall, cubicle housing, a straw yard and a pasture-based system. The welfare scores, calculated by COWEL for these husbandry systems, correspond with the general opinion about these systems. A tie-stall receives a low and a pasture-based system a high welfare score: 211 and 271, respectively. A husbandry system can receive a maximum of 313 on the welfare scale of COWEL. We conclude that COWEL can be used to rank husbandry systems on a welfare scale, and may be a useful tool to develop new, sustainable and welfare-friendly systems for dairy cattle.

Effect of different flooring systems on claw conformation of dairy cows

The effect of different flooring surfaces in walking and standing areas on claw conformation, claw horn growth, and wear was studied in 2 experiments during 2 consecutive housing seasons in a research dairy herd of 170 cows. In experiment 1, the flooring systems tested were solid rubber mats, mastic asphalt with and without rubber-matted feed-stalls, and aged concrete slats. In experiment 2, slatted concrete flooring was compared with slatted rubber flooring. The cows were introduced to the respective flooring systems in early lactation and their claws were trimmed before the exposure period. Toe length, toe angle, sole concavity, and claw width, as well as claw growth and wear rates were recorded for lateral and medial claws of the left hind limb. Claw asymmetry calculations were based on these claw measurements and on differences in sole protrusion between lateral and medial soles. Asphalt floors caused shorter toe length and steeper toe angle. They also increased wear on rear claws (5.30 +/- 0.31 and 5.95 +/- 0.33 mm/mo for lateral and medial claw, respectively; LSM +/- SE) and horn growth rate (5.12 +/- 0.36 and 5.83 +/- 0.31 mm/mo of lateral and medial claws, respectively). Rubber mats instead of asphalt in walking areas reduced wear (1.36 +/- 0.19 and 2.02 +/- 0.20 mm/mo for lateral and medial claw, respectively) and claw growth (3.83 +/- 0.23 and 3.94 +/- 0.17 mm/mo for lateral and medial claw, respectively). Rubber-matted feed-stalls together with asphalt walkways decreased claw wear (3.29 +/- 0.31 and 4.10 +/- 0.32 mm/mo for lateral and medial claw, respectively). The concavity of claw soles was reduced on asphalt, especially in the lateral rear claws. Rubber matting in feed-stalls prevented loss of sole concavity compared with asphalt. Claw asymmetry did not differ between flooring systems. While different access to abrasive flooring affected claw conformation, there was no evidence that flooring system influenced the disproportion between lateral and medial claws.

The effects of two out-wintering pad systems compared with free-stalls on dairy cow hoof and limb health

Lameness is one of the most serious health and welfare problems for dairy cows. This study compared hoof health, limb health and locomotion of dairy cows in three over-winter management systems. Treatments were: (1) an indoor free-stall system (FS), (2) outdoors on an uncovered woodchip pad (UP) and (3) outdoors on a covered woodchip pad (CP). Animals were assigned to treatments at drying off, remained on treatment until parturition, then turned out to pasture. Sole lesions were scored on assignment to treatment, at calving, and 6 weeks and 12 weeks post partum. Locomotion and skin lesions were scored on assignment to treatment, and every 2 weeks until parturition. Post-partum locomotion was scored weekly for 13 weeks. More FS cows were affected by limb lesions than CP cows, and these animals had the worst locomotion scores post calving. There was an effect of inspection, and interactive effect of inspection and treatment on sole lesion scores. UP cows had the highest sole lesion scores 12 weeks post partum probably due to softening of the hooves arising from exposure to moisture while on the woodchip pad. However, post partum, UP cows had better locomotion scores, and CP cows tended to have better scores than cows in FS. Both of these treatments were less likely to have a high tracking-up score than cows in FS. It is possible that cows in this treatment were able to exercise more, owing to the secure underfoot surface and lack of barriers, and this promoted limb flexibility. Although woodchip pads provided benefits for limb health and locomotion, the wood chip surface in both outdoor systems did not offer protective benefits to the hooves relative to housing on concrete. However, the provision of shelter on the pad somewhat overcame the problem of high sole lesion scores in the post-partum period.