Association between hoof trimming frequency in primiparous cows and hoof health and survival in second lactation.

Lameness, mostly resulting from claw lesions, causes major welfare problems in the dairy industry. One way to prevent claw lesions is hoof trimming, but the overall effect and the optimal hoof trimming frequency are unknown. In a retrospective cohort study, we investigated the association between hoof trimming frequency in primiparous cows and hoof health and culling in second lactation. We based our analysis on breed, calving and culling data in the period 2015-2018 for 30,613 primiparous cows in 202 Swedish dairy herds. Of the cows enrolled, 20% were not hoof-trimmed, 30% were trimmed once, 34% were trimmed twice, 13% were trimmed 3 times, and 2% were trimmed ≥ 4 times. We used multivariable mixed-effect logistic and multivariable multinomial logistic regression models to investigate the association between trimming frequency and 2 outcomes: hoof lesions at first trimming occasion within 90 d from second calving and culling in second lactation within 300 d after second calving. In general, cows trimmed 2 or 3 times during first lactation were at lower odds of having claw lesions compared with cows that were not trimmed (Odds Ratio (OR) = 0.66, 95% CI = 0.62-0.71 and 0.60, 95% CI = 0.55-0.66, respectively) or cows trimmed once (OR = 0.80, 95% CI = 0.75-0.85 and OR = 0.72, 95% CI = 0.66-0.79, respectively), and this beneficial effect was observed for most types of claw lesions. Moreover, cows trimmed 2, 3, or ≥ 4 times were at lower odds of being culled compared with cows that were not trimmed (OR = 0.71, 95% CI = 0.65-0.77, 0.68, 95% CI = 0.61-0.76 and 0.70, 95% CI = 0.54-0.90, respectively) or trimmed once (OR = 0.77, 95% CI = 0.71-0.83, OR = 0.74, 95% CI = 0.66-0.82 and OR = 0.75, 95% CI = 0.59-0.97, respectively). In particular, 2 trimmings, compared with 1 or no trimming, lowered the relative risk-ratio of dying or being euthanized on-farm, or being culled due to claw and leg disorders. More than 1 hoof trimming in first lactation also reduced the relative-risk ratio of being culled for other reasons. In conclusion, 2 or 3 hoof trimmings during first lactation were generally beneficial for hoof health in early second lactation and survival in second lactation. These findings can help improve animal welfare and production by reducing claw lesions, and thereby lameness among dairy cows, which would increase the longevity of dairy cows and the sustainability of the dairy industry.

Comparisons of recycled manure solids and wood shavings/sawdust as bedding material-Implications for animal welfare, herd health, milk quality, and bedding costs in Swedish dairy herds.

Increasing shortages and costs of common bedding materials have led dairy farmers in Sweden to consider using recycled manure solids (RMS), which are readily available and low cost, as an alternative bedding material. The main risks are effects on udder health and milk quality, but RMS could also affect animal welfare and claw health. The advantages and disadvantages of using RMS bedding have not been fully investigated, and findings in other countries cannot be directly applied to Swedish conditions and climate. This observational cross-sectional study investigated the use of RMS as bedding, regarding associations with certain aspects of animal welfare, herd health, milk quality, and bedding costs in Swedish dairy herds. Thirty-four dairy farms using RMS or wood shavings/sawdust (each n = 17) were compared. Each farm was visited 2 times during the housing period from 2020 to 2021, once from October to December and once from March to May. Dairy barns were observed, animal welfare was assessed, and freestall dimensions were measured. Farm owners were interviewed about housing system characteristics, herd performance, and herd management. Data on milk production and herd health were obtained from the Swedish official milk recording scheme for the indoor period from October to March. The prevalence of claw disorders and abnormal claw conformation were collected from the national claw health database for the period from October to May. On each farm visit, composite samples of unused bedding outside the barn and used bedding material from the freestalls, respectively, were taken for total bacterial count and DM analysis. Samples of bulk tank milk for determination of total bacterial count were taken in connection to the visits. In addition, samples of unused and used bedding material and manure from alleys for analysis of 3 Treponema species associated with digital dermatitis (DD) were gathered and analyzed. Total bacterial count was significantly higher in unused (8.50 log10 cfu/g) and used RMS bedding (9.75 log10 cfu/g) than in wood shavings/sawdust (used 4.74; unused 8.63 log10 cfu/g), but there were no significant differences in bulk milk total bacterial count (median 4.07 vs. 3.89 log10 cfu/mL) or SCC (median 243,800 vs. 229,200 cells/mL). The aspects of animal welfare assessed did not differ significantly between the 2 bedding systems, whereas the prevalence of total claw disorders (25.9% vs. 38.0% of trimmed cows), dermatitis (6.9% vs. 16.2% of trimmed cows) and sole ulcers (2.0% vs. 4.0% of trimmed cows) were significantly lower in the RMS herds. Treponema spp. were not detected in unused RMS material, but all RMS herds had presence of DD recorded at foot trimming. An economic assessment based on the interview results and price level from winter 2021 revealed that the costs of RMS bedding varied with amount of RMS produced. Thus, RMS is a potential alternative bedding material for dairy cows in Sweden and can be a profitable option for large dairy herds. However, the high level of total bacteria in the material requires attention to bedding and milking routines as well as regular monitoring of herd health.

Gait of dairy cows on floors with different slipperiness.

This study assessed the slip resistance of different types of solid flooring in cattle housing using a range of technical tests and gait analysis. Dynamic and static coefficient of friction, skid resistance, and abrasiveness were tested on concrete flooring with a smooth finish, a grooved pattern, or a tamped pattern, acid-resistant mastic asphalt, soft rubber mats, and a worn slatted concrete floor. Coefficients of friction and skid resistance were tested under clean and slurry-soiled conditions. Linear kinematic variables were assessed in 40 cows with trackway measurements after the cows passed over the floors in a straight walk. All gait variables were assessed as deviations from those obtained on the slatted concrete floor, which was used as a baseline. The coefficient of friction tests divided the floors into 3 categories: concrete flooring, which had a low coefficient of friction (0.29-0.41); mastic asphalt flooring, which had medium values (0.38-0.45); and rubber mats, which had high values (0.49-0.57). The highest abrasion (g/10 m) was on the asphalt flooring (4.48), and the concrete flooring with a tamped pattern had significantly higher abrasiveness (2.77) than the other concrete floors (1.26-1.60). Lowest values on the skid-resistance tests (dry/wet) were for smooth concrete (79/35) and mastic asphalt (65/47), especially with a slurry layer on the surface. Gait analysis mainly differentiated floors with higher friction and abrasion by longer strides and better tracking. Step asymmetry was lower on floors with high skid-resistance values. The most secure cow gait, in almost every aspect, was observed on soft rubber mats. Relationships between gait variables and physical floor characteristics ranged from average to weak (partial correlations 0.54-0.16). Thus, none of the physical characteristics alone was informative enough to characterize slip resistance. With reference to gait analysis, the abrasiveness of the hard surfaces was more informative than the coefficient of friction, but the effect of pattern was better detected by skid-resistance measurements. Consequently, several physical characteristics are needed to objectively describe the slip resistance of cattle floors. Soft rubber mats gave better tracking than hard, solid floors, even with a grooved surface or a tamped pattern.

Influence of grazing management on claw disorders in Swedish freestall dairies with mandatory grazing.

Our hypothesis was that grazing time, the number of days (duration) and number of hours per day, affected claw health. From Swedish freestall herds that fulfilled our criteria of claw-trimming routines, 201 herds were randomly selected for a telephone interview regarding grazing management. Herd data were retrieved from the Swedish Official Milk Recording Scheme. Claw disorders to be analyzed were recorded at maintenance claw trimming before and after the grazing period and included mild and severe dermatitis, severe heel-horn erosion, and sole ulcer (including severe sole hemorrhage). Any remark included one or more of these recorded disorders. The odds for having a recorded claw disorder at the autumn trimming in relation to grazing management, as well as to herd- and cow-related parameters, was tested using multilevel logistic regression models. The final statistical analysis included 17,600 cows in 174 herds, which were distributed from the south to the north of Sweden with decreasing length of mandatory grazing period because of climate. Grazing duration was statistically associated with the risk of sole ulcer, but it was not linear. However, grazing duration was not statistically associated with the odds for any remark, dermatitis, or heel-horn erosion. The odds for dermatitis were lower with access to pasture for 24 h compared with either day or night access. Otherwise, the number of hours that the animals had access to grazing per day was not significantly associated with any of the other analyzed claw disorders. Higher pasture stocking density (number of cow hours per day per hectare) was associated with a higher odds for dermatitis and sole ulcer. For all recorded claw disorders, the highest odds for having a disorder after the grazing period were consistently when the cow had the same claw disorder before the release to pasture. The positive effects of grazing on claw health were less than expected, and the previous known effects of breed, days in milk, parity, production system, housing environment, and management were verified for most claw disorders. If cows in today's loose housing systems have a more restrictive grazing than cows in tie-stall herds previously experienced, one cannot expect as strong an effect even if grazing is mandatory in all Swedish dairy cattle. Despite some positive effects of grazing, good stall environment and management during the housing period seem to be more important to obtain good claw health.

Kinematic changes in dairy cows with induced hindlimb lameness: transferring methodology from the field of equine biomechanics.

Lameness is a common issue on dairy farms, with serious implications for economy and animal welfare. Affected animals may be overlooked until their condition becomes severe. Thus, improved lameness detection methods are needed. In this study, we describe kinematic changes in dairy cows with induced, mild to moderate hindlimb lameness in detail using a "whole-body approach". Thereby, we aimed to identify explicable features to discriminate between lame and non-lame animals for use in future automated surveillance systems. For this purpose, we induced a mild to moderate and fully reversible hindlimb lameness in 16 dairy cows. We obtained 41 straight-line walk measurements (containing > 3 000 stride cycles) using 11 inertial measurement units attached to predefined locations on the cows' upper body and limbs. One baseline and ≥ 1 induction measurement(s) were obtained from each cow. Thirty-one spatial and temporal parameters related to limb movement and inter-limb coordination, upper body vertical displacement symmetry and range of motion (ROMz), as well as pelvic pitch and roll, were calculated on a stride-by-stride basis. For upper body locations, vertical within-stride movement asymmetry was investigated both by calculating within-stride differences between local extrema, and by a signal decomposition approach. For each parameter, the baseline condition was compared with induction condition in linear mixed-effect models, while accounting for stride duration. Significant difference between baseline and induction condition was seen for 23 out of 31 kinematic parameters. Lameness induction was associated with decreased maximum protraction (-5.8%) and retraction (-3.7%) angles of the distal portion of the induced/non-induced limb respectively. Diagonal and lateral dissociation of foot placement (ratio of stride duration) involving the non-induced limb decreased by 8.8 and 4.4%, while diagonal dissociation involving the induced limb increased by 7.7%. Increased within-stride vertical displacement asymmetry of the poll, neck, withers, thoracolumbar junction (back) and tubera sacrale (TS) were seen. This was most notable for the back and poll, where a 40 and 24% increase of the first harmonic amplitude (asymmetric component) and 27 and 14% decrease of the second harmonic amplitude (symmetric component) of vertical displacement were seen. ROMz increased in all these landmarks except for TS. Changes in pelvic roll main components, but not in the range of motion of either pitch or roll angle per stride, were seen. Thus, we identified several kinematic features which may be used in future surveillance systems. Further studies are needed to determine their usefulness in realistic conditions, and to implement methods on farms.

Kinematic gait characteristics of straight line walk in clinically sound dairy cows.

The aim of this study is to describe the kinematic gait characteristics of straight line walk in clinically sound dairy cows using body mounted Inertial Measurement Units (IMUs) at multiple anatomical locations. The temporal parameters used are speed and non-speed normalized stance duration, bipedal and tripedal support durations, maximal protraction and retraction angles of the distal limbs and vertical displacement curves of the upper body. Gait analysis was performed by letting 17 dairy cows walk in a straight line at their own chosen pace while equipped with IMU sensors on tubera sacrale, left and right tuber coxae (LTC and RTC), back, withers, head, neck and all four lower limbs. Data intervals with stride by stride regularity were selected based on video data. For temporal parameters, the median was calculated and 95% confidence intervals (CI) were estimated based on linear mixed model (LMM) analysis, while for limb and vertical displacement curves, the median and most typical curves were calculated. The temporal parameters and distal limb angles showed consistent results with low variance and LMM analysis showed non-overlapping CI for all temporal parameters. The distal limb angle curves showed a larger and steeper retraction angle range for the distal front limbs compared with the hind limbs. The vertical displacement curves of the sacrum, withers, LTC and RTC showed a consistent sinusoidal pattern while the head, back and collar curves were less consistent and showed more variation between and within cows. This kinematic description might allow to objectively differentiate between normal and lame gait in the future and determine the best anatomical location for sensor attachment for lameness detection purposes.

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.

Reducing added sugar intake in Norway by replacing sugar sweetened beverages with beverages containing intense sweeteners - a risk benefit assessment.

A risk benefit assessment in Norway on the intake of added sugar, intense sweeteners and benzoic acid from beverages, and the influence of changing from sugar sweetened to diet beverages was performed. National dietary surveys were used in the exposure assessment, and the content of added sugar and food additives were calculated based on actual contents used in beverages and sales volumes provided by the manufactures. The daily intake of sugar, intense sweeteners and benzoic acid were estimated for children (1- to 13-years-old) and adults according to the current intake level and a substitution scenario where it was assumed that all consumed beverages contained intense sweeteners. The change from sugar sweetened to diet beverages reduced the total intake of added sugar for all age groups but especially for adolescent. This change did not result in intake of intense sweeteners from beverages above the respective ADIs. However, the intake of acesulfame K approached ADI for small children and the total intake of benzoic acid was increased to above ADI for most age groups. The highest intake of benzoic acid was observed for 1- to 2-year-old children, and benzoic acid intake in Norwegian children is therefore considered to be of special concern.

Effect of different flooring systems on weight and pressure distribution on claws of dairy cows.

Weight and pressure distribution on the claw were studied in Swedish Holsteins housed in different flooring systems. A total of 127 cows housed in different sections of the experimental barn were used. Each section had different flooring in the walking and standing areas. There were rubber mats or abrasive mastic asphalt flooring on the alleys or a low-abrasive slatted concrete floor. Some sections had feed-stalls equipped with rubber mats; other sections did not. The vertical ground reaction force, contact area, and average contact pressure were determined on the left hind foot using the I-Scan system and analyzed with the F-scan system. These determinations were made in each of the following 3 zones of the claw: bulb, wall, and sole. Most of the weight on claws exposed to concrete floors was carried by the bulb (37.4 +/- 3.5 and 18.3 +/- 2.9% of weight exerted on the foot in the lateral and medial claw, respectively) and the wall zone (20.0 +/- 2.6 and 13.4 +/- 2.4% on lateral and medial claw, respectively). The weight and pressure distribution in cows kept on sections with rubber covered alleys but passing daily over the asphalt floor on their way to the milking parlor did not differ in any zones, except for lateral bulbs, compared with those exposed to slatted concrete alone. Still, the weight bearing of the sole zone in cows kept on rubber mats without access to asphalt was less than that of cows kept on concrete slatted floors (5.1 +/- 0.7 vs. 12.7 +/- 1.1% and 1.1 +/- 0.5 vs. 8.7 +/- 0.7% in lateral and medial claws, respectively). In cows kept on asphalt flooring without feed-stalls, most weight was exerted to the sole zone (36.2 +/- 2.9 and 22.2 +/- 1.8% in lateral and medial claws, respectively). Feed-stalls in combination with asphalt flooring yielded a decreased total contact area (30.1 +/- 1.2 cm(2)) compared with asphalt floors without feed-stalls (35.7 +/- 1.2 cm(2)). The largest total contact area was obtained on the asphalt floor without feed-stalls, resulting in a lower contact pressure (39.8 +/- 2.3 N/cm(2)) than in claws exposed to concrete (66.0 +/- 2.7 N/ cm(2)) or rubber mats (56.7 +/- 1.7 N/cm(2)). In conclusion, housing with abrasive floors resulted in claws with increased contact area at the sole surface and therefore, decreased contact pressure, but reduced the weight-bearing role of the strongest part of the claw capsule, the claw wall.

Dairy cow preferences for soft or hard flooring when standing or walking.

Concrete is the most commonly used alley flooring in confined dairy herds because of its qualities of construction and ease of cleaning. Nevertheless, the hardness, abrasiveness, and slipperiness of concrete floors have adverse effects on animal well-being and health, and yielding rubber flooring is becoming popular as a way of improving the flooring conditions on walkways. The aim of this study was to investigate preferences of dairy cows for rubber compared with concrete flooring under the conditions of a commercial dairy farm. The study was conducted in an organic dairy herd with free-stall housing. Floor preference was tested on groups of standing cows in a 120-m2 holding pen before milking, and 1 yr later on a 12- x 3-m walkway. The holding pen and the walkway were divided lengthwise into 2 identical sections. Two types of solid rubber mats (soft and extra soft) were tested against solid concrete in the holding pen. Slatted and solid rubber mats were tested against slatted concrete in the walkway. Each floor type was tested over 4 d on the left side and 4 d on the right side of the holding pen and the walkway, respectively. Concrete flooring on both sides of the sections was tested as a control before the testing of different section materials. All observations of the distribution of cows in the sections were made from video recordings captured in association with the afternoon milking. The number of cows on each section was recorded approximately every 7 min in the holding pen, and continuously on the walkway. A significantly higher proportion of cows stood on the side with the soft and extra soft rubber mats (65.1 +/- 2.7 and 69.3 +/- 2.6%, respectively, mean +/- SEM) compared with the control distribution when only the solid concrete was available (50.9 +/- 3.9%). A significantly higher proportion of nonlame cows walked exclusively on the side with the slatted (64.5 +/- 5.4%, d 4) or solid rubber mats (68.2 +/- 5.1%, d 4) compared with controls (28.9 +/- 4.3%). Lame cows within a group of walking cows did not show a higher preference for soft flooring as distinct as nonlame cows (52.7 +/- 6.9 and 59.4 +/- 6.2% for the solid and slatted rubber mats, respectively, at d 4 vs. 40.3 +/- 6.2% for control), presumably because of competition with other, higher ranked cows. It was concluded that the majority of cows preferred to walk and stand on soft rubber rather than on concrete flooring.

Development of automatic surveillance of animal behaviour and welfare using image analysis and machine learned segmentation technique.

In this paper the feasibility to extract the proportion of pigs located in different areas of a pig pen by advanced image analysis technique is explored and discussed for possible applications. For example, pigs generally locate themselves in the wet dunging area at high ambient temperatures in order to avoid heat stress, as wetting the body surface is the major path to dissipate the heat by evaporation. Thus, the portion of pigs in the dunging area and resting area, respectively, could be used as an indicator of failure of controlling the climate in the pig environment as pigs are not supposed to rest in the dunging area. The computer vision methodology utilizes a learning based segmentation approach using several features extracted from the image. The learning based approach applied is based on extended state-of-the-art features in combination with a structured prediction framework based on a logistic regression solver using elastic net regularization. In addition, the method is able to produce a probability per pixel rather than form a hard decision. This overcomes some of the limitations found in a setup using grey-scale information only. The pig pen is a difficult imaging environment because of challenging lighting conditions like shadows, poor lighting and poor contrast between pig and background. In order to test practical conditions, a pen containing nine young pigs was filmed from a top view perspective by an Axis M3006 camera with a resolution of 640 × 480 in three, 10-min sessions under different lighting conditions. The results indicate that a learning based method improves, in comparison with greyscale methods, the possibility to reliable identify proportions of pigs in different areas of the pen. Pigs with a changed behaviour (location) in the pen may indicate changed climate conditions. Changed individual behaviour may also indicate inferior health or acute illness.

Psychiatrist and nonphysician mental health provider staffing levels in health maintenance organizations.

OBJECTIVE: This study attempts to determine the ratio of full-time-equivalent psychiatrists to members and that of nonphysician mental health professionals to psychiatrists in staff and group model health maintenance organizations (HMOs), and to compare the psychiatrist-to-member ratio with previous estimates of the required psychiatrist-to-population ratios in fee-for-service and managed care environments. METHODS: The Group Health Association of America (now the American Association of Health Plans) collected data on mental health staffing, enrollments, and other characteristics for 30 staff and group model HMOs. The authors evaluated the number of full-time-equivalent psychiatrists and nonphysician mental health professionals per 100,000 HMO members, and the ratio of full-time-equivalent nonphysician mental health professionals to psychiatrists. RESULTS: The overall mean number of full-time-equivalent psychiatrists and nonphysician mental health professionals per 100,000 members in the responding HMOs was 6.8 and 22.9, respectively. The overall mean ratio of nonphysician professionals to psychiatrists was 4.5. The overall number of psychiatrists per 100,000 members is less than half the requirement estimated by the Graduate Medical Education National Advisory Committee in 1980, which assumed a fee-for-service environment, but it is about 40% to 80% greater than that estimated by other studies under the assumption of a managed care environment. CONCLUSIONS: Although a practice environment dominated by managed care may not require as high a psychiatrist-to-population ratio as a predominantly fee-for-service environment, it may well support a greater number of psychiatrists than previous studies have suggested.

Clinical staffing in staff- and group-model HMOs.

Analysts frequently have used health maintenance organization (HMO) staffing patterns as a yardstick for estimating national clinical workforce requirements. Based on a nationwide survey of fifty-four staff- and group-model HMOs, the largest sample yet used in an analysis of this type, this DataWatch examines physician-to-member ratios, the use of nonphysician providers, and HMOs' methods of estimating clinical staffing needs. Overall physician staffing ratios and primary care physician staffing ratios closely resemble those reported in previous studies, but they exhibit wide variability and are strongly correlated with HMO size. Although caution should be exercised when using HMO staffing ratios in projections of physician workforce requirements, the ratios described here support projections of a specialty physician surplus.

Effects of a rubber-slatted flooring system on cleanliness and foot health in tied dairy cows.

Effects on animal cleanliness and foot health of a new rubber-slat system for tied dairy cows, with the ability to drain faeces and urine, were studied in a 2-year controlled quasi-randomised trial in a Swedish university herd. Swedish Red and White cows were kept tied in 42 traditional long-stalls with rubber mats. In total, 82 cows were observed. In 21 stalls, the rearmost 0.74m of the solid stall floor was replaced with nine rubber-coated 53mm wide slats, divided by 29mm slots. The cleanliness was assessed subjectively weekly (year 1) or bi-weekly (year 2) by observations of the hind part of the body. Claw measurements and foot health in hind feet were assessed in connection with hoof trimmings at the beginning, middle and end of the housing period. The foot-health recordings were blinded to flooring. For the analysis of both cleanliness (1781 records, 73 cows) and foot health (240 records, 79 cows), logistic regression was applied, using marginal models and cow observations as repeated measures within each year. The risk of getting dirty on the rubber-slatted floor was significantly lower (odds ratio 0.12 for hind feet when short stall dividers were used, 0.39 for hind legs and 0.38 for thighs and udder), comparing with the solid stall floor. The prevalence of foot diseases in hind feet at trimming was significantly lower on the rubber slats (odds ratio 0.23 for dermatitis, 0.09 for heel horn erosion, and 0.34 for sole ulcer or sole or white line haemorrhage).

Effects of conformation and management system on hoof and leg diseases and lameness in dairy cows.

Foot and leg disorders that result in lameness tend to increase with more confined management systems and increased production. Many factors affect hoof health, including genetics, conformation, diet, contagious agents, hygiene, housing systems, animal behavior, and management. This article describes relationships between hoof health and some of these factors as well as methods for prevention of lameness on a herd basis.

Laminitis in young dairy calves fed a high starch diet and with a history of bovine viral diarrhoea virus infection.

Six of the 33 calves born in a Swedish dairy herd during a period of four months developed laminitis when they were eight to 12 weeks old. The clinical signs included difficulty in rising, a stiff gait, overgrown claws and haemorrhages in the sole horn. Samples of blood were taken from four of the calves when they had shown signs of laminitis for two to seven weeks; the serum concentrations of calcium, phosphorus and vitamin D3, the activities of aspartate aminotransferase and glutathione peroxidase, and the patterns of serum proteins were within their normal ranges. The feet of the same four calves were examined after slaughter; the third phalanx of each calf was rotated and its distal end osteolytic. Histologically there was separation and degeneration of the squamous cells of the white line, and thromboses and vasculitis in the fine vessels of the corium. Four of the six affected calves were persistently infected with bovine viral diarrhoea virus and one had antibodies against the virus. From six weeks of age the calves had been fed rye wheat, a hybrid seed rich in starch, and this may have contributed to the outbreak of laminitis.

A photometric method for recording hoof diseases in cattle, with special reference to haemorrhages of the sole.

After cleaning and trimming, the sole surface and interdigital space of the hooves of cows are photographed in a standardized way. The colour slides are projected on to a screen and the haemorrhages of the sole (reflecting Pododermatitis aseptica diffusa) and the lesions of Dermatitis interdigitalis and Erosio ungulae are scored according to their severity and extent by 2 people who do not know the identity of the cows. In a repeatability test the correlation coefficients between 2 assessments of the haemorrhages in the sole ranged between 0.78 and 0.88 for assessments of the front hooves, the hind hooves and all the hooves together.

Haemorrhages of the sole horn of dairy cows as a retrospective indicator of laminitis: an epidemiological study.

Eleven herds with clinical laminitis problems and 11 control herds were studied for 2 consecutive years. All the claws were trimmed and photographically recorded once each year, 2 to 6 months after the cows had calved. The haemorrhages of the sole horn were evaluated and scored for each digit, and data relevant to the factors associated with an increased risk of laminitis for each herd were collected and related to these scores for sole haemorrhages. It was found that the laminitic herds were more prone to the sole lesions than the control herds, the hind claws were more prone than the front claws, the primiparous cows were more prone than the multiparous cows and the Swedish Friesian cows were more prone than the Swedish Red and White cows. High scores were also correlated with hard floors (ie concrete) in the cow stalls, with fewer than 4 daily feedings of concentrates, with a short time allocated for the cows to eat concentrates, with feeding concentrates only at the first meal in the morning and in the afternoon and with the interaction between these last 2 variables.

Sole haemorrhages in tied heifers in early gestation as an indicator of laminitis: effects of diet and flooring.

The influence of feeding a high concentrate diet and of different types of floor surface on the prevalence and severity of haemorrhages of the sole horn was studied in 60 Swedish Friesian heifers during early pregnancy. For 4 weeks, out of a total observation period of 17 weeks, half the animals were offered 6.5 kg/day of concentrates while the others were fed a standard diet consisting mainly of roughage. Half the animals were kept on rubber mats and half on a concrete floor. The hooves were trimmed and the soles were photographed at the start and at the end of the experiment. The photographs were evaluated, each claw was scored for sole haemorrhages, and the total score for all 8 claws was calculated. No differences were observed between the groups in the scores of sole haemorrhages at any trimming. The scores were significantly higher at the first than at the second trimming, probably as a consequence of an abrupt change of floor surface 2-3 months before the first trimming. The study provides indirect evidence that events relating specifically to calving are likely to be crucial risk factors for sole haemorrhages and laminitis.

Sole haemorrhages in tied primiparous cows as an indicator of periparturient laminitis: effects of diet, flooring and season.

Fifty-six tied heifers calving in autumn (trial I) and 21 tied heifers calving in late spring (trial II) were fed either a high or a low concentrate diet from 3 weeks before expected calving until 13 weeks after calving. Half the heifers in trial I were kept on concrete floors and the others were kept on rubber mats; all the heifers in trial II were on concrete floors. The hooves were trimmed and the soles were photographed 3 weeks before expected calving and again 13 weeks after calving. The photographs were evaluated, each claw was scored for sole haemorrhages, and the total score for all 8 claws was calculated. Before calving there were no differences between the groups of heifers within trial I or trial II, but the heifers in trial II had higher scores than those in trial I. Thirteen weeks after calving the scores had increased in both trials. In trials I the animals fed the high concentrate diet and kept on concrete floors had the highest score, and the type of floor had a greater influence than the level of concentrates fed. The heifers calving in the autumn had higher scores than those calving in the spring. The sudden change from being at pasture to being housed, and the events related to the periparturient period were the most significant factors for the development of sole haemorrhages.