Risk factors for lameness and hock injuries in Holstein herds in China

The objective was to investigate the association between herd-level management and facility design and the prevalence of lameness and hock injuries in high-producing dairy cows on commercial freestall farms in China. Housing and management measures, such as stall design, bedding type, and milking routine were collected for the high-producing pen in 34 farms in China. All cows in the pen were gait scored using a 5-point scale, and evaluated for hock injuries using a 3-point scale. Measures associated with the proportion of clinically (score ≥3) or severely (score ≥4) lame cows, and the proportion of cows having at least a minor hock injury (score ≥2) or severe injury (score = 3) at the univariable level were submitted to multivariable general linear models. The prevalence [mean ± SD (range)] of clinical and severe lameness were 31 ± 12 (7–51) and 10 ± 6% (0– 27%), respectively, and the prevalence of cows with at least a minor hock injury and with severe injuries was 40 ± 20 (6 – 95) and 5 ± 9% (0 – 50%), respectively. The prevalence of clinical lameness and severe lameness decreased with herd size (estimate = −0.35 ± 0.09% for a 100-cow increase for clinical lameness; estimate = 0.15 ± 0.06% for a 100-cow increase for severe lameness). Prevalence increased with barn age >9 yr (estimate = 12.73 ± 4.42% for clinical lameness; estimate = 5.79 ± 2.89% for severe lameness). These 2 variables combined explained 49% of the variation in clinical lameness and 30% of the variation in severe lameness. The prevalence of all hock injuries and severe hock injuries decreased with deep bedding (estimate = −20.90 ± 5.66% for all hock injuries; estimate = −3.65 ± 1.41% for severe hock injuries) and increased with barn age >9 yr (estimate = 16.68 ± 7.17% for all hock injuries; estimate = 6.95 ± 1.75% for severe injuries). These 2 variables explained 52 and 58% of the variation, respectively. In conclusion, large variation existed across farms in prevalence of lameness and hock injuries. Changes in housing and management may help control the prevalence of lameness and hock injuries in the emerging dairy industry in China.     

Cow preference and usage of free stalls compared with an open pack area

Free-stall housing systems are designed to provide a comfortable and hygienic lying area, but some aspects of stall design may restrict usage by cows. The aim of this study was to compare free-stall housing with a comparable lying area (open pack) without stall partitions. We predicted that cows would spend more time lying down and standing in the bedded area when provided access to an open pack than when in free stalls. We also predicted that cows would spend less time standing outside of the lying area and less time perching with the front 2 hooves in the lying area when using the open pack. Groups (n = 8) of 12 cows each were provided access to either the open pack or stalls. After a 7-d adaptation period, each group was tested sequentially in the 2 treatments for 3 d each. This no-choice phase was followed by an 8-d choice phase during which cows had simultaneous access to both treatments. During the no-choice phase, cows spent more time lying down (13.03 ± 0.24 vs. 12.48 ± 0.24 h/d) and standing with all 4 hooves in the bedded area (0.96 ± 0.12 vs. 0.41 ± 0.12 h/d) of the open pack than in the stalls. During the choice phase, cows spent more time lying down (7.20 ± 0.29 vs. 5.86 ± 0.29 h/d) and standing with all 4 hooves in the bedded area (0.58 ± 0.07 vs. 0.12 ± 0.07 h/d) of the open pack than in the stalls. In both the no-choice (1.66 ± 0.24 vs. 0.55 ± 0.24 h/d) and choice (0.55 ± 0.07 vs. 0.29 ± 0.07 h/d) phases, cows spent more time standing with just 2 hooves in the stalls than in the open pack. In conclusion, cows spent more time lying and standing with all 4 hooves in the bedded open pack than in the stalls. Additionally, cows spent more time standing in the alley and standing with just the front 2 hooves on the bedding in the stalls than in the bedded open pack; increased standing time on wet concrete is a known risk factor for lameness.     

Prevalence of lameness and leg lesions of lactating dairy cows housed in southern Brazil: Effects of housing systems

Within the last few decades, the North American and European dairy industries have been collecting information about lameness and leg injury prevalence on dairy farms and have tried to develop solutions to mitigate these ailments. Few published articles report the prevalence of lameness and leg lesions in areas outside of those 2 regions, or how alternative housing systems, such as compost-bedded packs, affect the prevalence of these maladies. The objectives of this study were to compare the prevalence of lameness and leg lesions on confined dairies that used freestall, compost-bedded packs, or a combination of these 2 systems in Brazil. Data were collected in the autumn and winter of 2016 from 50 dairy farms located in Paraná state, including 12 compost-bedded pack dairies (CB), 23 freestall dairies (FS), and 15 freestall dairies that used compost-bedded packs for vulnerable cows (FS+C). A visit to the farm consisted of a management questionnaire, an inspection of the housing areas as well as the milking parlor, and an evaluation of all lactating cows as they exited the parlor for lameness (score 1–5), hygiene (score 0–2), body condition score (score 1–5), and hock and knee lesions (score 0–1). Median 1-way chi-squared test was used to compare production systems. We found no difference between farm types in management practices related to hoof health management or average daily milk production per cow [31 (29–33.9) kg/d; median (quartile 1–3)], percentage of Holstein cattle in the herd [100% (90–100%)], conception rate [35.8% (30.2–38%)], or pregnancy rate [15% (13.7–18%)]. The CB farms were smaller [85 (49.5–146.5) milking cows] than both the FS [270 (178–327.5) milking cows] and FS+C farms [360 (150–541.5) milking cows). The overall prevalence of severe lameness (score 4 and 5) across all farms was 21.2% (15.2–28.5%) but was lower on the CB farms [14.2% (8.45–15.5%)] in comparison to the FS [22.2% (16.8–26.7%)] and the FS+C farms [22.2% (17.4–32.8%)]. Less than 1% of all cows scored on CB farms were observed with swollen or wounded knees (or both), which was lower than either the FS or FS+C farms [7.4% (3.6–11.9%) and 6.4% (2.6–11.8%) of all cows scored, respectively]. The same pattern was found for hock lesions, where the farm-level prevalence within the 3 different housing types was 0.5% (0–0.9%), 9.9% (0.8–15.3%), and 5.7% (2.6–10.9%) for CB, FS, and FS+C farms, respectively. No differences between farm systems were observed for hygiene or body condition score. On average, 2.7% (0.8–10.9%) of lactating cows had a soiled side, 15.4% (2.1–37.4%) had dirty legs and 1.7% (0–9.3%) had dirty udders. The average herd-level body condition score across farms was 2.9 (2.9–3), with 0.86% of the all cows scored having a body condition score <2.5. These results indicate that lameness prevalence on confined dairies in Brazil is high and highlight the need for remedial changes in environmental design and management practices. We found that CB farms in this region had reduced lameness and lesions in relation to FS or FS+C dairies.     

Effects of sand and straw bedding on the lying behavior, cleanliness, and hoof and hock injuries of dairy cows

This experiment compared the effects of sand and straw bedding in free stalls on resting time, cleanliness, hock injuries, and hoof health of dairy cows and tested whether cow preferences for a bedding material depended on the familiarity with the material. A total of 52 dairy cows were kept either on straw bedded concrete stalls or sand stalls for at least 21 wk. The lying behavior was observed, and hock lesions, hoof health, and cleanliness of the cows and stalls were measured. A 5-d preference test between sand and straw stalls was conducted at the end of the experiment. The total daily duration of lying was longer for cows on straw bedding than on sand bedding (straw 749 ± 16 vs. sand 678 ± 19 min). During the preference test, cows that had been kept on straw bedding preferred lying in straw stalls [straw 218.7 (133.4 to 239.7) vs. sand 9.0 min (2.8 to 44.8)]; however, cows that had been kept on sand showed no preference [straw 101.3 (51.7 to 205.9) vs. sand 94.3 min (54.1 to 156.1, median and interquartile range)]. Although there were no differences in the dirtiness of stalls, the cows using straw stalls were dirtier than cows using sand stalls [straw 6.04 (5.39 to 6.28) vs. sand 4.19 (3.62 to 5.16)]. At the end of experiment the severity of hock lesions was lower for cows on sand than for cows on straw [sand 0.5 (0.0 to 1.0) vs. straw 1.0 (1.0 to 2.0)]. The improvement in overall hoof health over the observation period was greater for cows kept on sand compared with cows kept on straw [sand −2.00 (−3.75 to −0.25) vs. straw 0.00 (−2.00 to 2.00)]. Straw bedding increased the time that cows spend lying, and cows preferred straw stalls to sand stalls. However, previous experience with sand reduces avoidance of sand stalls. Sand stalls were advantageous for cow cleanliness and health; hock lesions and claw diseases healed more quickly for cows using sand stalls compared with straw.     

Hock injury prevalence and associated risk factors on organic and nonorganic dairy farms in the United Kingdom

The presence of hock injury was assessed in the milking herds of 80 dairy farms (40 organic, 40 nonorganic) across the United Kingdom. A wide range of information on farm management and husbandry was gathered via interview to assess the factors contributing to hock damage for all 80 farms, and a comprehensive building appraisal was conducted for 40 farms visited during the winter housing period. The prevalence of hock lesions was lower on organic compared with nonorganic farms (37.2 vs. 49.1%). Prevalence of hock damage was greater in the spring than fall (59.9 vs. 21.6%) and cows housed in free-stalls had a greater prevalence of hock lesions than those housed on straw (46.0 vs. 25.0%). Prevalence of hock damage increased with lactation number. In the analysis of fall/spring data, the age first mated, herd biosecurity, duration of summer grazing, and cow milk yield were significant factors relating to herd hock damage. Larger herds had a greater proportion of cows with hock swellings. Farms with a shorter calving interval had more cows with hock swellings. Factors relating to housing conditions that were positively associated with the prevalence of hock damage were low feed face space per cow, inferior passageway cleanliness, low total standing area per cow, and the type of bedding added to the free-stall. To assess whether free-stall versus straw-pen or organic versus nonorganic farms had different sets of risk factors, the data were reanalyzed for these types separately. For the straw-pen farms a high culling rate was associated with more hock damage. Within nonorganic farms, the length of summer grazing was significant, with longer periods meaning less hock injury. The prevalence of hock injuries on many UK farms, both organic and non-organic, exceeded levels that are deemed acceptable for cow comfort. Efforts are needed to improve housing standards to reduce the prevalence of hock injury and consequently improve cow welfare.     

The stall-design paradox: Neck rails increase lameness but improve udder and stall hygiene

Housing conditions for dairy cows are thought to affect lameness, but almost no experimental work has addressed this link. The aim was to assess the effect of one feature of free-stall design, the position of the neck rail, testing the prediction that cows will be more likely to become lame if using pens with the neck rail positioned such that it prevents standing fully inside the stall. Cows (n = 32) were housed in 8 pens. Treatments were tested using a crossover design; treatments were allocated alternately to pens at the beginning of the experiment and switched halfway through the 10-wk experiment. Cows spent 27 ± 3 min/d standing with all 4 feet in stalls with less restrictive neck rails. In contrast, cows averaged just 1 ± 3 min/d when the neck rail was positioned restrictively. Cows spent less time standing with only the front 2 feet in the stall with less restrictive neck rails (33 vs. 49 ± 6 min/d). Gait scores improved when cows were kept in the less restrictive stalls and worsened when cows were kept in pens with the restrictive neck rail (median score 2.5 vs. 3.5 after 5 wk on treatment). Of 13 new cases of lameness, 11 occurred in pens with the restrictive neck-rail position. Similarly, of the 16 new cases of sole lesions, 15 occurred during the period when cows were housed in pens with a restrictive neck rail. Stalls with the neck rail positioned less restrictively had higher contamination scores than stalls with the restrictive neck rails (3.7 vs. 0.4 ± 0.2), and cows using those stalls had dirtier udders and longer teat-cleaning times (8.3 vs. 7.0 ± 0.2 min for 12 cows). This study provides the first experimental evidence that aspects of stall design can reduce the risk of lameness and hoof disease. The results illustrated that changes in design that resulted in improvements in cow comfort and hoof health came at the expense of cow and stall cleanliness.     

Benchmarking cow comfort on North American freestall dairies: Lameness,leg injuries,lying time,facility design,and management for high-producing Holstein dairy cows

In this paper, we describe a novel approach to corporate involvement in on-farm assessment, driven by the desire to provide a service for dairy producers and to create a vehicle for engagement on issues of dairy cow welfare. This program provides producers with feedback on animal-based (including gait score, leg injuries, and lying time) and facility-based (including freestall design, bedding practices, feed bunk design and management, and stocking density) measures that can be used to better address their management goals. The aim of this paper is to describe variation in the prevalence of lameness and leg injuries, lying behavior, facility design, and management practices for high-producing cows on freestall dairy farms in 3 regions of North America: British Columbia (BC; n = 42); California (CA; n = 39); and the northeastern United States (NE-US; n = 40). Prevalence of clinical lameness averaged (mean ± SD) 27.9 ± 14.1% in BC, 30.8 ± 15.5% in CA, and 54.8 ± 16.7% in NE-US; prevalence of severe lameness averaged 7.1 ± 5.4% in BC, 3.6 ± 4.2% in CA, and 8.2 ± 5.6% in NE-US. Overall prevalence of hock injuries was 42.3 ± 26.2% in BC, 56.2 ± 21.6% in CA, and 81.2 ± 22.5% in NE-US; prevalence of severe injuries was 3.7 ± 5.2% in BC, 1.8 ± 3.1% in CA, 5.4 ± 5.9% in NE-US. Prevalence of swollen knees was minimal in CA (0.3 ± 0.6%) but high (23.1 ± 16.3%) in NE-US (not scored in BC). Lying times were similar across regions (11.0 ± 0.7 h/d in BC, 10.4 ± 0.8 h/d in CA, 10.6 ± 0.9 h/d in NE-US), but individual lying times among cows assessed varied (4.2 to 19.5 h/d, 3.7 to 17.5 h/d, and 2.8 to 20.5 h/d in BC, CA, and NE-US, respectively). These results showed considerable variation in lameness and leg injury prevalence as well as facility design and management among freestall farms in North America. Each of the 3 regions had farms with a very low prevalence of lameness and injuries, suggesting great opportunities for improvement on other farms within the region.     

Udder health of cows changing from tie stalls or free stalls with conventional milking to free stalls with either conventional or automatic milking

Udder health and milk production were monitored in cows transferred from tie stalls or loose housing with conventional milking to loose housing with either automatic or conventional milking. Data were collected from 182 Finnish farms from September 1999 to February 2006. Data from the first year before and first year after the changes were compared. A total of 88 herds changed from conventional milking (CM herds) to automatic milking (AM herds), 29 of which were housed in tie stalls and 59 of which were housed in a loose housing barn before the change. Additionally, 94 CM herds milked in loose housing barns that had been housed in tie stalls before the change were included. Milk record data consisted of annual herd size, parity, breed, calving dates, test day data [date, milk yield, and cow somatic cell count (SCC)] and records for treatments of clinical mastitis. Calculations were made for energy-corrected milk yield and logarithmic SCC (logSCC), proportion of cows at risk that experienced an SCC >200,000 cells/mL for the first time (highSCC), and number of treatments of clinical mastitis within a herd. Cows in tie stalls had higher milk yield (28.5 ± 0.29 vs. 26.5 ± 0.46 kg/d) and a lower logSCC (4.86 ± 0.01 vs. 4.95 ± 0.02) than cows in loose housing barns before the change. After the change, CM herds had slightly better udder health than AM herds because the proportion of cows at risk for highSCC was larger in AM herds (3.3 vs. 2.1%). The change in milking and housing systems caused a decline of 0.8 ± 0.25 kg/d per cow in energy-corrected milk yield, a slight increase in cow logSCC (from 4.88 ± 0.01 to 4.93 ± 0.01), and an increase of 0.6% in the proportion of cows having highSCC (from 2.5 to 3.1). The impact was clearer on herds that began automatic milking. Based on the results, the increase in bulk milk SCC of herds milked automatically in Finland was probably due to reduced separation of mastitic milk in AM herds.     

Influence of free-stall flooring on comfort and hygiene of dairy cows during warm climatic conditions

An evaluation of behavioral and hygienic conditions was carried out with 4 materials used as free-stall flooring for dairy cows: polyethylene vinyl acetate (EVA) and polypropylene vinyl acetate (PVA) mats, wood shavings, and solid manure. The free-stall type selected by cows was evaluated in response to changes in environmental temperature and humidity. Two tests were used: 1) a preference test, in which 8 cows were housed in a pen with 32 free stalls and 4 types of flooring; and 2) an aversion test, in which 32 cows were placed in 4 pens, each with 8 free stalls. The free stalls in each pen had a single type of bedding material. These tests showed that the comfort of dairy cows was predominantly influenced by environmental conditions. The preference test for lying showed that cows preferred free-stall floors with EVA mats over those with PVA mats, wood shavings, and solid manure (332.4 ± 24.0 vs. 130.8 ± 6.2, 160.9 ± 23.7, and 102.6 ± 23.2 min/d, respectively), but under conditions of heat stress, with a temperature-humidity index > 80, they chose wood shavings and solid manure lying areas. These results were confirmed by the aversion test. In all experimental and environmental conditions, the PVA mats were the least suitable. The mats contaminated with organic manure and the free stalls bedded with wood shavings and organic solids did not differ in either the coliform load on the lying surfaces (EVA mats: 290 ± 25; PVA mats: 306 ± 33; wood shavings: 290 ± 39; and solid manure: 305 ± 23 log₁₀ cfu/mL) or the total bacterial count in the raw milk (EVA mats: 232 ± 22; PVA mats: 233 + 24; wood shavings: 221 ± 24; and solid manure: 220 ± 25 log₁₀ cfu/mL). These results demonstrate that the comfort of dairy cows housed in barns with free stalls as resting areas does not depend only on the material used, but also on the value of the material in microenvironmental conditions.     

The effect of out-wintering pad design on hoof health and locomotion score of dairy cows

This study compared locomotion, hoof health, and lameness of dairy cows confined in either indoor free stalls (FS) or 1 of 3 out-wintering pad (OWP) designs. Out-wintering pad treatments were 1) uncovered OWP with a concrete feed apron (UP); 2) covered OWP with a concrete feed apron (CO); and 3) uncovered OWP on top of which grass was ensiled so that the cows could self-feed (SP). Cows were assigned to treatment at drying off using a randomized complete block design. They remained on treatment until calving, when they were turned out to pasture. Sole lesions, heel erosion, dermatitis, and claw hardness on both hind feet were scored according to severity at assignment to treatment, at calving, and 9 and 14 wk postpartum. Locomotion score was recorded weekly after calving for 14 wk. Incidence of clinical lameness was recorded during the treatment period and in the subsequent lactation. Treatment had no effect on sole lesion score, but scores increased over time (calving = 5.5 ± 1.3, wk 9 = 10.8 ± 1.3, wk 14 = 14.2 ± 1.3, mean ± SE). Self-fed cows had higher heel erosion scores (6.4 ± 0.4) than FS and CO cows (4.7 ± 0.4 and 4.7 ± 0.4, respectively) at calving. Cows on SP had the highest dermatitis scores [1.14 (0-2) mean (interquartile range)] and FS cows the lowest [0.51 (0-0)]. Hooves were hardest at assignment to treatment (43.9 ± 0.6) with a significant reduction in hardness at calving (40.0 ± 0.6). The hooves of CO cows were harder than those of SP and UP cows (CO = 43.3 ± 0.7, SP = 41.7 ± 0.7, UP = 41.7 ± 0.7, Shore D scale). There was no treatment effect on locomotion scores or lameness incidence. Higher dermatitis scores and heel erosion in SP may be due to exposure to excreta and moisture, because the SP treatment had no manure removal system at the feed face. In FS, the alleys and the feed face were cleaned regularly by automatic scraper, explaining the lower dermatitis scores recorded indoors. Providing shelter for OWP likely reduced exposure to environmental moisture. This ensured that the hooves of CO cows remained as hard as those of FS cows. Low correlations between hardness and pathologies indicate that other factors are involved in the development of hoof pathologies. Confining dry dairy cows on OWP does not increase locomotion scores or lameness incidence.     

The Effect of Out-Wintering Pad Design on the Synchrony of Dairy Cow Behavior

The study investigated differences in behavior synchrony of dairy cows during the winter confinement period when managed in 1 of 3 out-wintering pad (OWP) systems, or indoors in free-stall housing. There were 2 replicates of each treatment, and observations were carried out on 3 recording occasions in January and February 2006. On each recording occasion, behavior was recorded every 30 min between 0600 and 0130 h the following day (n = 40). The outcomes for measurement were eligible cows lying (ECL), cow comfort index (CCI), and proportion of animals feeding (AF). Autocorrelation as an indicator of synchrony was calculated using the Durban-Watson statistic and compared across treatments. A centered moving average was calculated, used to obtain the residual, and compared between treatments. Low autocorrelations were recorded in free stalls (39.6 ± 0.1%), indicating lower temporal behavioral synchrony than in the 3 OWP designs. Overall, the greatest proportion of ECL, CCI, and AF occurred in free stalls (60%). However, high proportions (>90%) of ECL were recorded on OWP in the early morning, whereas the range of ECL in free stalls (22 to 87%) was lower. The low overall proportions for ECL (44, 52, and 54%) and CCI (48, 55, and 58%) in the OWP were caused by the cows standing without feeding during daylight hours. Nevertheless, these cows performed more synchronized lying at night, and their behavior was more highly autocorrelated (65.9 ± 0.1, 73.3 ± 0.1, and 52.3 ± 0.1%) than cows in free stalls. Synchrony of behavior is part of the normal behavior repertoire of herd-living animals such as dairy cattle, and OWP may promote a more natural circadian behavior pattern than do free-stall systems. It is important that indices such as CCI and ECL are utilized at appropriate times of the day, when cows are expected to lie; that is, during the evening time. Estimated acceptable levels of these indices may be dependent on the confinement system employed.     

Animal welfare in cross-ventilated, compost-bedded pack, and naturally ventilated dairy barns in the upper Midwest

The objective of this cohort study was to investigate animal welfare in 2 newer dairy housing options in the upper Midwest, cross-ventilated freestall barns (CV) and compost-bedded-pack barns (CB), compared with conventional, naturally ventilated freestall barns (NV). The study was conducted on 18 commercial dairy farms, 6 of each housing type, in Minnesota and eastern South Dakota. The primary breed in all farms was Holstein; 1 CV and 1 NV herd had approximately 30% Jersey-Holstein crossbreds. All freestall herds used sand for bedding. Farms were visited 4 times (once in each season) between January and November 2008, and approximately 93% of all animals in each pen were visually scored on each visit. Outcome-based measurements of welfare (locomotion, hock lesions, body condition score, hygiene, respiration rates, mortality, and mastitis prevalence) were collected on each farm. Lameness prevalence (proportion of cows with locomotion score ≥3 on a 1 to 5 scale, where 1 = normal and 5 = severely lame) in CB barns (4.4%) was lower than that in NV (15.9%) and CV (13.1%) barns. Lameness prevalence was similar between CV and NV barns. Hock lesion prevalence (proportion of cows with a lesion score ≥2 on a 1 to 3 scale, where 1 = normal, 2 = hair loss, and 3 = swelling) was lower in CB barns (3.8%) than in CV (31.2%) and NV barns (23.9%). Hygiene scores (1 to 5 scale, where 1 = clean and 5 = very dirty) were higher for CB (3.18) than CV (2.83) and NV (2.77) barns, with no differences between CV and NV barns. Body condition scores, respiration rates, mastitis prevalence, culling, and mortality rates did not differ among housing systems. The CV and NV barns were evaluated using the cow comfort index (proportion of cows lying down in a stall divided by all animals touching a stall) and the stall usage index (proportion of cows lying divided by all animals in the pen not eating). The CV barns tended to have greater cow comfort index (85.9%) than the NV barns (81.4%) and had greater stall usage index (76.8% and 71.5%, respectively). Dairy cattle housed in CB barns had reduced lameness and hock lesions compared with those housed in freestall barns and had no adverse associations with body condition, respiration rates, mastitis prevalence, culling, or mortality. When comparing the 2 freestall housing options, CV barns had improved cow comfort indices compared with NV barns. Although cows in CB barns had better feet and leg health, as indicated by the reduced lameness and hock lesion prevalence, acquiring bedding and managing the bedded pack could limit their use.     

Lying behavior as an indicator of lameness in dairy cows

Lameness is widely recognized as one of the most serious welfare and production concerns in the dairy industry. Our objectives were to evaluate the associations between lying behavior and lameness, and to determine whether lying behavior can be used as a diagnostic tool for lameness. Electronic data loggers recorded lying behavior of 1,319 cows from 28 farms at 1-min intervals for 5 d. These cows were gait scored according to a 5-point Numerical Rating System (NRS), and categorized as NRS ≤2, NRS = 3, or NRS = 4; no cow was scored as NRS = 5. Lameness was dichotomized twice: LAME (NRS ≥3) and SEVLAME (NRS = 4). Data were divided into 2 groups: 11 farms using deep-bedded stalls (DB) and 17 farms using mattress stalls (MAT). Differences in the daily lying time (h/d), frequency of lying bouts (n/d), duration of lying bouts (min/bout), and the standard deviation of bout duration (min/bout) between LAME or SEVLAME cows and those that were not were tested using mixed models. Receiver operating characteristic curves were constructed to identify behavioral thresholds to distinguish SEVLAME cows from the rest. Odds ratios for SEVLAME were estimated using logistic regression. Overall, 28.5% of cows were LAME including 7.3% that were SEVLAME. The prevalence of SEVLAME was higher on MAT farms than on DB farms (9.3 ± 1.3 vs. 4.4 ± 1.2%, respectively). SEVLAME cows on DB farms spent 12.8 [confidence interval (CI): 12.0 to 13.7] h/d lying down compared with 11.2 (CI: 10.7 to 11.8) h/d for cows that were not SEVLAME. These cows had longer duration of lying bouts [95.3 (CI: 84.6 to 107.3) vs. 80.3 (CI: 74.9 to 86.1) min/bout] and greater SD of bout duration [44.4 (CI: 41.1 to 48.0) vs. 50.7 (CI: 44.1 to 58.3) min/bout]. There were no behavioral differences among lameness categories on MAT farms. Within DB farms, cows with lying times >14.5 h/d had 16.2 (5.8 to 45.2) times higher odds of being SEVLAME. Cows with average lying bouts >90 min/bout were at 3.0 (1.2 to 7.4) times higher odds of being SEVLAME, and cows with average SD of bout duration >55 min/bout were at 4.1 (1.7 to 9.9) times higher odds of being SEVLAME. These results show that high lying times, long lying bouts, and variability in the duration of lying bouts were associated with lameness, and that stall surface influenced the behavioral responses of lame cows.     

Associations between herd-level factors and lying behavior of freestall-housed dairy cows

Our objective was to investigate the associations between herd-level factors and lying behavior of high-producing dairy cows housed in freestall barns. Lying behavior of approximately 40 focal cows in one high-producing pen was monitored on each of 40 farms in the northeastern United States (NE) and 39 farms in California (CA). All cows within the pen were gait scored using a 1-to-5 scale to calculate the prevalence of clinical lameness (score ≥3) and severe lameness (score ≥4). Facility and management measures, including stall design, bedding, and flooring type within the pen, were collected. Herd-level factors associated with daily lying time, standard deviation (SD) of daily lying time, frequency of lying bouts, and lying bout duration at the univariate level were submitted to multivariable general linear models. In the NE, daily lying time increased with the use of deep bedding (estimate = 0.80 ± 0.31 h/d) and as average days in milk (DIM) of the focal cows increased (estimate = 0.08 ± 0.04 h/d for a 10-d increase in DIM). The SD of daily lying time decreased as stall stocking density increased (estimate = −0.08 ± 0.03 h/d for a 10% increase), and increased with the presence of rubber flooring in the pen (estimate = 0.16 ± 0.08 h/d) and percentage of stalls with fecal contamination (estimate = 0.04 ± 0.01 h/d for a 10% increase). Frequency of lying bouts decreased (estimate = −1.90 ± 0.63 bouts/d) and average bout duration increased (estimate = 15.44 ± 3.02 min) with the use of deep bedding. In CA, where all farms used deep bedding, daily lying time increased as average DIM of the focal cows increased (estimate = 0.08 ± 0.03 h/d for a 10-d increase). The SD of daily lying time decreased when feed was delivered more than once per day (estimate = −0.24 ± 0.08 h/d). The percentage of lame cows was correlated with the percentage of stalls with fecal contamination (r = 0.45), which in turn was associated with fewer (estimate = −0.25 ± 0.06 bouts/d) and longer lying bouts (estimate = 1.85 ± 0.39 min/d). These findings suggest that lying time be interpreted in conjunction with variability in lying time and bout structure and in context with lameness prevalence, production parameters, and facility characteristics.     

Associations between cow hygiene, hock injuries, and free stall usage on US dairy farms

This cross-sectional study evaluated cow comfort measures in free stall dairies across the United States as part of the National Animal Health Monitoring System's Dairy 2007 study. The study was conducted in 17 states and evaluations were completed between March 5 and September 5, 2007. Assessors recorded hygiene and hock scores, number of cows housed in the pen, the number of cows standing with only the front feet in a stall, standing fully in a stall, and lying in a stall. Facility design measures included bedding type, bedding quantity, stall length and width, presence of a neck rail or brisket locator, and relevant distances from the rear and bed of the stall. Of the 491 operations that completed the cow comfort assessment, 297 had Holstein cows housed in free stalls and were included in this analysis. Negative binomial models were constructed to evaluate the following outcomes: the number of cows that were very dirty, had severe hock injuries, stood with front feet in the stall, stood with all feet in the stall, and were lying in the stall. Hygiene was better on farms that did not tail dock cows compared with those that did (5.7 vs. 8.8% were dirty) and on farms located in the study's west region compared with those located in the east region (5.2 vs. 9.7% were dirty). Severe hock injuries were less common on farms in the west than those in the east (0.5 vs. 4.1%). In addition, severe hock injuries were less common on farms that used dirt as a stall base or sand as bedding compared with farms that did not. A higher percentage of cows was standing with front feet in the stall at higher ambient temperatures (incidence rate ratio = 1.016) and as time since feeding increased (incidence rate ratio = 1.030). A lower percentage of cows were standing with front feet in the stall when the stalls were shorter and when there were fewer cows per stall. Standing fully in a stall was performed by a higher percentage of cows during the summer than during the spring (13.6 vs. 8.1%), when cows were provided free stalls with rubber mats or mattresses, and as the distance from the rear curb to neck rail increased. A higher percentage of cows were lying in a stall when sand bedding was used, when bedding was added more frequently, and during the spring months. Results of this national survey indicate that tail docking provides no benefit to cow hygiene and that stall base and bedding are key factors influencing hock injuries and stall usage on US free stall dairy farms.     

Genetic parameters for claw and leg health, foot and leg conformation, and locomotion in Danish Holsteins

The purpose of this study was to estimate the genetic correlations among claw and leg health and potential indicator traits. Claw health was defined as absence of heel horn erosion, interdigital dermatitis, interdigital phlegmon, interdigital hyperplasia, laminitis, and sole ulcer. Leg health was defined as absence of hock infection, swollen hock, and bruising. The potential indicators were locomotion and foot and leg conformation, represented by rear leg side view, rear leg rear view, foot angle, and apparent hock quality and bone structure. The study was conducted using records from 429,877 Danish Holstein cows in first lactation. Binary health traits were divided into 3 subcategories: claw health, leg health, and absence of all claw and leg disorders. Genetic (r_g) and phenotypic correlations were estimated using a bivariate linear sire model and REML. Estimated heritabilities were 0.01 for all 3 combined claw and leg health traits (on the observed binary scale), 0.09 for locomotion, 0.14 for rear leg rear view, 0.19 for rear leg side view, 0.13 for foot angle, 0.22 for apparent hock quality, and 0.27 for apparent bone structure. Heritabilities were 0.06 and 0.01 for claw health and leg health, respectively, when transformed to the underlying continuous scale. Claw and leg disorders are an increasing problem for Danish Holsteins, but genetic improvement of claw and leg health is challenging because the traits have low heritabilities. Claw and leg health were separate but correlated traits (r_g = 0.35). Locomotion and rear leg rear view were useful indicator traits for claw health (r_g = 0.46 and r_g = 0.21, respectively), whereas hock quality and bone structure were useful indicators for leg health (r_g = 0.42 and 0.26, respectively). Claw and leg health should be considered as separate traits in genetic evaluations that also include the useful indicator traits to compensate for low heritability of the health traits.     

Behavior of cows during and after peak feeding time on organic and conventional dairy farms in the United Kingdom

The behavior of groups of housed, lactating dairy cattle was observed over 2 winter housing periods on 20 organic farms and 20 conventional farms in the United Kingdom. Three methods were used: (1) 6 video-clips of 10 min duration were captured of cows feeding at sections of the feed-bunk face during the peak feeding period (0 to 90 min) and continuously observed for aggressive interactions among cows; (2) the proportion of cows at the feed-bunk face was scanned every 15 min for 4.5 h to include the peak feeding period (0 to 255 min); and (3) all nonfeeding behaviors were scanned every 15 min for 2.5 h after the peak feeding period (120 to 255 min). The latter scans were analyzed post hoc for measures of cow comfort (freestall farms only). Management and health data were collected on each farm. On farms with open-fronted feed-bunk faces, a greater number of aggressive interactions occurred at the feed-bunk face at peak feeding time on organic farms than on conventional farms (organic = 36.3 ± 4.4; conventional = 29.1 ± 3.0). Higher proportions of cows were at the feed-bunk face at peak feeding on organic farms than on conventional farms (organic = 0.58 ± 0.04; conventional = 0.48 ± 0.03). Housing type (freestall versus straw pen) explained most differences in postfeeding behavior (proportion of ruminating cow in alleyways: freestalls = 0.16 ± 0.06 vs. straw-pen = 0.08 ± 0.03), with few differences between organic and conventional herds. On freestall farms, the proportions of cows on organic farms lying down postfeeding was smaller than in conventional herds (organic = 0.38 ± 0.09 vs. conventional = 0.43 ± 0.07). Differences in behavior around peak feeding time could be associated with the reduction in food “quality” on organic farms compared with the energy requirement of the cows, with cows on organic farms being highly motivated to feed. A correlation was observed between farms that had high amounts of lying and farms that had high lameness prevalence (R² = 55.3), suggesting a complex relationship between comfort and pain. Overall, the behavior of dairy cows on organic farms was not different from that of conventionally reared cows, and the results suggest that most behavioral welfare problems relating to housing could be alleviated by management practices.     

Short communication: Herd-level reproductive performance and its relationship with lameness and leg injuries in freestall dairy herds in the northeastern United States

The objectives of this study were to describe herd-level reproductive outcomes and their associations with the prevalence of lameness, hock injuries and knee injuries in freestall dairy herds in the northeastern United States. Five reproductive outcomes (calving to conception interval, CCI; calving interval, CI; conception risk at the first artificial insemination, CR1; insemination rate, IR; and pregnancy rate, PR) were measured from Dairy Comp 305 (Valley Agricultural Software, Tulare, CA) for a 12-mo period for all multiparous cows in each of the 53 herds assessed. The prevalence of lameness, hock injuries, and knee injuries was assessed in 1 high-producing group. The means (± standard deviation) for the 5 reproductive outcomes were as follows: CCI = 128 ± 10 d, CI = 404 ± 10 d, CR1 = 36 ± 5%, IR = 60 ± 7%, and PR = 20 ± 3%. The average prevalence of clinical lameness, hock injuries, and knee injuries were 45 ± 20%, 58 ± 31%, and 16 ± 15%, respectively. Univariable associations between the reproductive outcomes and the prevalence of lameness and leg injuries were tested and significant predictors were submitted to a model that controlled for the confounding effects of herd size, 305-d mature equivalent milk production of the high-producing group, and use of deep bedding. A higher prevalence of lameness was associated with poorer reproductive performance, although the relationships were weak: herds with a higher prevalence of lameness had longer average CCI (slope estimate = 0.16 ± 0.07; R² = 0.09) and CI (slope estimate = 0.14 ± 0.07; R² = 0.07). These results indicate that management to reduce lameness may improve reproductive performance.     

Management factors associated with impaired locomotion in dairy cows in England and Wales

Forty-nine farms in England and Wales were visited on 4 occasions between February 2003 and March 2004. A total of 21,693 scores of locomotion were assigned to 7,722 cattle. Locomotion was assessed on a 3-point scale by observing the posture of a cow's back while standing and walking (1 = sound, 2 = not sound, 3 = lame). Data on measurable factors potentially associated with locomotion were collected from all farms using direct observations of the farm environment and a comprehensive farmer interview. The mean herd locomotion score was 1.77 ± 0.02. There was no significant difference in mean herd locomotion scores between 5 herds housed in straw yards (1.72 ± 0.02) and 44 herds housed in free stalls (1.78 ± 0.02), possibly because of lack of power. A GLM was produced using data from the 44 herds housed in free stalls, with the mean farm locomotion score of all cows examined on all 4 visits as the outcome variable. Factors associated with an elevated locomotion score were dry cows kept in straw yards compared with free stalls (increase in locomotion score = 0.06 ± 0.03), pregnant heifers kept with milking cows in winter compared with being kept with dry cows (increase in locomotion score = 0.09 ± 0.03), aisle widths of <3 m compared with widths of ≥3 m (increase in locomotion score = 0.06 ± 0.02), a curb height of ≤15 cm compared with a height of >15 cm (increase in locomotion score = 0.07 ± 0.03), routine trimming of hooves of all cows by a hoof trimmer or by the farmer compared with no routine hoof trimming (increase in locomotion score = 0.18 ± 0.04 and 0.13 ± 0.03 respectively), feeding corn silage to milking cows compared with feeding other forage types (increase in locomotion score = 0.10 ± 0.03), and the use of automatic scrapers in the free-stall barn compared with tractor scrapers (increase in locomotion score = 0.10 ± 0.03). These variables were correlated with many other management variables. The use of automatic scrapers was correlated with the use of sawdust on rubber mats in free stalls. Curb height was negatively correlated with increasing distance of the neck rail from the front (head end) of the free stall. These putative risk factors support the hypothesis that locomotion score is linked to management factors; in particular, the combination of sawdust on rubber mats with automatic scrapers was associated with elevated locomotion scores.