Effects of type of forage fed to dairy heifers: associations between claw characteristics, clinical lameness, environment and behaviour.

Heifers were reared separately on wet fermented (WF) (grass silage based) or dry unfermented (DU) (straw based) diets. Clinical lameness was recorded and physical claw attributes were measured regularly, up to six months after calving at approximately two years of age. Two months before calving, some aspects of animal behaviour and the properties of slurry were studied. The incidence of lameness due to claw horn lesions was significantly higher (P < 0.01) in WF than in DU. WF suffered more serious heel erosion prior to calving (P < 0.05) and had softer claw horn at two (heel and axial sole) out of five sites throughout (P < 0.01 and P < 0.05). The slurry produced by WF had lower total solids content (P < 0.05) and viscosity (P < 0.001). WF spent longer standing and feeding (P < 0.001). It is proposed that standing for longer in less viscous slurry contributed to softer claw horn and more severe heel erosion, predisposing WF to claw horn lesions causing lameness. Reducing contact with low dry matter slurry is recommended for improving claw health.

Effect of forage type on claw horn lesion development in dairy heifers.

In a continuous design study the claw health of 54 Holstein-Friesian heifer calves was recorded from three months of age until six months after first calving (30 months of age). Pre-calving heifers were either fed a wet, fermented grass silage-based diet (WF) or a dry, unfermented straw and concentrate based diet (DU), apart from grazing during their first summer. Approximately one month before calving both groups were fed a silage-based diet and afterwards all received a silage and concentrate lactation ration. Claws were examined four times during rearing, once pre-calving, and four times during lactation. Both white line and sole lesions were significantly worse for WF than DU both during rearing and throughout first lactation although the effect was not as consistent over time for white line lesions. It is concluded that for optimal claw health youngstock diets should not be heavily based on wet grass silage (less than 25% DM).

A comparison of hoof lesions and behaviour in pregnant and early lactation heifers at housing.

Lameness, hoof lesion development and behaviour were compared for two groups of 10 heifers: one in early pregnancy (PH), the other in early lactation (LH). Both groups were housed in the summer in cubicles under identical conditions. Behavioural observations commenced immediately after housing, and then at 2, 4 and 6 weeks post-housing. Locomotion scores were assessed weekly, and feet were examined for lesions at approximately -1, 0, 1 and 2 months after housing. All four feet were photographed, lesions were scored subjectively for severity, and lesion size and position were estimated using image analysis techniques. LH already had greater total lesion scores before housing. More severe linear lesions in the LH group were associated with reduced lying, and less idling, increased standing in cubicles and more disturbed lying behaviour.

The effect of feeding grass silage in early pregnancy on claw health during first lactation.

Two groups of eight Holstein-Friesian heifers were fed either a grass-silage-based diet (S) or one based on meadow hay supplemented with 1.8 kg/day barley concentrate mix (H) during cubicle housing as young stock (and in early pregnancy). Lameness and claw lesion development were monitored from approximately four weeks before until 20 weeks after first calving. No significant difference was found between S and H for claw conformation or horn growth and wear. Both groups showed net wear immediately after calving. The prevalence of poor locomotion and the extent of lesion development 20 weeks after calving (when they were highest) were significantly (P< 0.05) higher in S than H. It was concluded that feeding grass silage to young stock may deleteriously affect subsequent claw health and that this risk factor requires further study.

A systematic compilation and classification of the literature on lameness in cattle.

This paper presents the first systematic review of the literature on lameness in cattle. It identifies, tabulates and classifies relevant published work and was conducted using electronic reference databases (BIDS ISI, BIOSIS, MEDLINE and the CAB Abstracts CD-ROM). A total of 1373 unique references were obtained from 1981 to 2000, of which 914 were written in the English language. A written search protocol was designed to ensure transparency and repeatability. Pilot studies were undertaken to create search terms that minimised bias and ensured relevance. Electronic files of the search terms allow the database to be updated in future. A further 93 references were included from the most recent international conference on lameness giving a total of 1007 English language references. The systematic review process is described, including a method of classifying papers according to their study design and statistical analysis, and it is hoped that other veterinary researchers will conduct similar reviews in their fields. The compiled and classified references are available as a searchable database through the web-sitehttp://cattle-lameness.dhs.org/. The review may be used in several ways; to identify practical interventions to reduce lameness in dairy cows and to use the resultant web-site as the basis of a decision support system for farmers, veterinarians and advisors.

Claw lesions in dairy cattle: development of sole and white line haemorrhages during the first lactation.

The development of claw haemorrhages was monitored in first-calving dairy heifers from 4 weeks before calving to 32 weeks after calving. Before calving, lesions were few but the number, extent and severity of claw haemorrhages increased following simultaneous calving and housing. Lesions were most severe in the white line at 9 weeks, and in the sole at 14 weeks, but recovery began while the animals were still housed. That the increase in white line lesions after calving, and the subsequent recovery preceded that of the sole, suggests that the pathogenesis of the lesions may differ in these two anatomical regions. It is proposed that an initial insult to the corium primarily affects the laminar region and that corium damage increases with the resulting alteration in the physical forces on the sole.

Observations of lameness, hoof conformation and development of lesions in dairy cattle over four lactations.

Lameness and lesions in the claws of 31 autumn-calving Holstein Friesian dairy cows were recorded from before their first-calving until their fifth lactation. The animals were managed by the same herdsman and housed adjacently in the same building in one of two herds grazed either on clover-rich pastures (herd 1) or on conventional ryegrass (herd 2). All four hooves were examined routinely four times during each lactation, and claw lesions were scored for severity and drawn on hoof maps. Heel erosion and infectious skin conditions of the hoof were also recorded, and hoof conformation, hardness, and growth and wear were measured. The animals' locomotion was scored weekly throughout the winter housing period and any observed to be lame were examined to determine the cause. The development of lesions was modelled by using hierarchic smoothing splines. There was no significant effect of herd except on the prevalence of lameness in lactation 2 when the incidence of (inter)digital dermatitis was higher in herd 2. Lesion and locomotion scores were significantly higher by lactation 4 (P<0.05). There were significant effects (P<0.05) of weeks postcalving on lesion formation, claw conformation, and heel erosion.

Correlations of measurements of subclinical claw horn lesions in dairy cattle.

Measurements were made of the extent of sole and white line lesions on the claws of 115 Holstein-Friesian cows on at least three and at most 16 occasions, and some cows were followed up to their third lactation. All the measurements were made between 12 weeks before calving and 45 weeks after calving. In total, 1016 repeated observations were made. Correlations were calculated between pairs of claws, between types of lesion (sole and white line), and between pairs of the different measurements (number of lesions, proportion of the claw affected, maximum severity score and proportion of the claw affected weighted for severity). The outer hind claws had the greatest extent of lesions of both types. Spearman correlation coefficients and confidence intervals measured the strength of the association. All the associations between claws were positive, suggesting that the lesions did not occur in isolation. Sole and white line lesions were not associated at individual observation points. Lesions on the left and right claws were markedly similar, except for sole lesions on the two inner hind claws, and for white line lesions on the two outer hind claws.

Effects of time of year and reproductive state on the proliferation and keratinisation of bovine hoof cells.

Cell proliferation and protein synthesis (keratinisation) were measured in vitro in hoof biopsy samples taken from two groups of seven heifers, the first calving in the winter and the second in the summer. Both parameters were significantly higher in summer than in winter irrespective of the heifers' reproductive state. The mean (se) measure of the rate of protein synthesis was 199 (27) dpm/microg DNA/hour in summer and 4 (1) dpm/microg DNA/hour in winter, and the equivalent values for cell proliferation (measured as DNA synthesis) were 375 (56) dpm/microg DNA/hour and 17 (4) dpm/microg DNA/hour. Changes around parturition depended on the time of the year. In the winter-calving heifers, the rates of proliferation and keratinisation increased significantly after calving from 22.3 (7.2) to 70.4 (16.6) and from 2.1 (0.7) to 12.4 (2.8) dpm/microg DNA/hour, respectively. In the summer-calving heifers, proliferation decreased from 388.2 (91.0) to 66.7 (9.6) dpm/microg DNA/hour but the rate of keratinisation did not change. Lesion scores and locomotion scores deteriorated after parturition, especially in the winter-calving group. The hooves were harder in summer than winter but their hardness was not affected by the heifers' reproductive state.