Making tiestalls more comfortable: II. Increasing chain length to improve the ease of movement of dairy cows.

Although most farms in Canada still use tiestall housing for dairy cows, little information is available pertaining to cow comfort and behavior in such systems. Tiestalls are often criticized as they offer a reduced dynamic space to cows, thereby restricting their ability to move. The object of this study was to see if increasing the length of the tie chain provides cows with improved movement opportunities and to measure its effect on cows' rising and lying movements and behaviors. Two treatments were tested: the current recommendation of 1.00 m (recommended) and a longer chain of 1.40 m (long). Twenty-four cows (12/treatment) were blocked by parity number and lactation stage, then randomly allocated to a treatment and a stall within one of 2 rows in the research barn for 10 wk. Leg-mounted accelerometers were used to record lying behaviors and moments of transition between lying and standing positions for all cows. Cows were video-recorded for 24 h/wk using cameras positioned above the stall. The videos were used to evaluate the cows' rising and lying-down movements on wk 1, 2, 3, 6, 8, and 10. Six rising and 6 lying-down motions per cow per week were assessed by a trained observer to detect the presence of abnormal behaviors. Differences between and within treatments over time were analyzed in SAS (SAS Institute Inc., Cary, NC) using a mixed model with treatment, week, and block as fixed effects and with row and cow as random effects. Data from wk 1-3 were grouped together as the short-term effects, and those from wk 8-10 as the long-term effects. Week 6 was used as the mid-term assessment for analysis. Multiple comparisons between terms were accounted for using a Scheffé adjustment. Results indicate that duration of intention movements (exploratory head movements made by cows before lying down) is shorter in cows with longer chains (13.6 ± 1.03 s vs. 16.8 ± 1.01 s). It was also significantly shorter in the long term compared with the short term for both treatments (13.3 ± 0.92 s vs. 16.9 ± 0.81 s). These results suggest that increasing the chain length improves the cows' ease of movement and transitions, although all cows became more at ease in their surroundings with time. It may provide evidence of a potential way to improve the dynamic space provided to cows in tiestall systems, using a simple, affordable modification.

Making tiestalls more comfortable: III. Providing additional lateral space to improve the resting capacity and comfort of dairy cows.

Dairy cows housed in tiestalls are restricted to one space; therefore, this space should be designed to accommodate all the activities cows need to perform. Lying is a very important behavior for dairy cows as well as a critical measure in the assessment of stall designs, to ensure that the cows' needs for resting space are met. The objective of this study was to determine if increasing tiestall width alters the lying behavior of lactating dairy cows. Two treatments were compared: the current recommendation (139 cm) and a double stall (284 cm). Sixteen cows were blocked by parity and lactation stage, then randomly allocated to a treatment and a stall within 1 of 2 rows in the research barn, for 6 wk. The average stall length was 188 cm. Leg-mounted accelerometers were used to record lying behaviors. Cows were video-recorded 24 h/wk using surveillance cameras positioned above the stalls. Video data from wk 1, 3, and 6 were extracted at a rate of 1 image/min and analyzed by a trained observer to assess the position and the location of the cow's body, head, and limbs during the lying hours. Lying behaviors and frequency of each position and location were analyzed in SAS (SAS Institute Inc., Cary, NC) using a mixed model in which treatment, block, and week were included as fixed factors, and cow and row as random factors. Multiple comparisons were adjusted using the Scheffé method. Results indicate that cows in double stalls fully extended their hindlimbs more often than single stall cows (21.7 vs. 7.6% of lying time). Cows in double stalls also intruded in the neighboring stalls with their hindlimbs less often (1.3 vs. 14.7% of lying time), instead positioning them inside their own stall more often (92.7 vs. 84.6% of lying time). Use of the second stall in the double stall group totaled 11.6, 5.1, 33.8, and 18.0% of lying time, respectively, for the head, front legs, hind legs, and body. Total lying time was not statistically different between double (716 min/d) and single stall (671 min/d) groups. Contacts with stall hardware during lying-down movements were also less frequent in double stalls (43.1 vs. 77.1% of lying events) compared with single stalls. These results suggest that dairy cows housed in double stalls modified their resting habits and used the extra space made available to them. Increasing stall width beyond the current recommendation is likely to benefit the cows by improving their ability to rest.

Associations between on-farm animal welfare indicators and productivity and profitability on Canadian dairies: I. On freestall farms.

Motivating dairy producers to financially invest in the improvement of their animals' comfort and welfare can pose some challenges, especially when financial returns are uncertain. Economic advantages for dairy producers associated with increased animal welfare are likely to come from either a premium paid for the milk or increased productivity. The aim of the current study was to evaluate the associations between measures of herd productivity and farm profitability and animal-, management-, and resource-based indicators of cow welfare and comfort. The cow welfare measures were collected during a cow comfort assessment conducted on 130 Canadian freestall dairy farms, including 20 using an automatic milking system. Herd productivity and farm profitability measures were retrieved or calculated from data collected by the regional dairy herd improvement programs, and included milk production and quality, longevity, and economic margins over replacement costs. Univariable and multivariable linear regression models were used to assess the associations between welfare indicators and productivity and profitability measures. Increased yearly corrected milk production was associated with reduced prevalence of cows with knee lesions [ß = 7.40; 95% confidence interval (CI): 2.6, 12.2], dirty flanks (ß = 26.9; 95% CI: 7.4, 46.5), and lameness (ß = 11.7; 95% CI: 3.3, 20.1). The farms' economic margin per cow, calculated over replacement costs, was associated with the within farm average lying time standard deviation (ß = -7.2; 95% CI: -12.7, -1.7), percent of stalls with dry bedding (ß = 6.4; 95% CI: 1.4, 11.4), and prevalence of cows with knee lesions (ß = -5.1; 95% CI: -8.9, -1.3). Some of the relationships found were complex, including several interactions between the animal-, management-, and resource-based measures. Overall, the results suggest that improved cow comfort and welfare on freestall farms is associated with increased herd productivity and profitability, when the latest is calculated by the margins over the replacement costs.

Associations between on-farm cow welfare indicators and productivity and profitability on Canadian dairies: II. On tiestall farms.

The use of tiestall housing for dairy cows is often criticized due to the reduced freedom of movement it offers for the animals. Maximizing comfort is especially important in tiestall farms to ensure an acceptable level of cow welfare. Motivating dairy producers to make financial investments directly aimed toward the improvement of their animals' welfare can be challenging, especially when financial returns are uncertain. The aim of this study was to evaluate the existence of associations between on-farm animal welfare and indicators of farm productivity and profitability in tiestall farms. The prevalence of animal-, resource-, and management-based welfare indicators was collected on 100 Canadian tiestall farms during a cow comfort study. Records from the dairy herd improvement agency were retrieved and used to calculate the farms' productivity and profitability measures. Univariable and multivariable linear regressions were used to assess the associations between welfare indicators and milk production, milk quality, cow longevity, and economic margins calculated over replacement costs. Increased yearly average corrected milk production was associated with longer average lying time [ß = 272; 95% confidence interval (CI): 94, 450] and a higher proportion of cows fitting the tie-rail height (ß = 6; 95% CI: 1, 11). Lower yearly average somatic cell count was associated with lower percentages of stalls mostly soiled with manure (ß = -3.7; 95% CI: -1.9, -5.4) and a lower proportion of cows with body condition score ≤2 (ß = -5.1; 95% CI: -2.3, -8.3). The average margin per cow over replacement costs was positively associated with average lying time (ß = 147; 95% CI: 27, 267), percent of stall not soiled with manure (ß = 7.2; 95% CI: 3.0, 11.3), and the frequency of scheduled hoof trimming per year. Some of the relationships found included interactions between animal- and management-based welfare measures. For example, the relationship between lameness prevalence and average milk production was modified through the milk production genetic index. Overall, the results show that improved cow comfort and welfare on tiestall farms is associated with increased productivity, cow longevity, and profitability when estimated through margins calculated over the replacement costs. Producers should aim to optimize all aspects of stall comfort to enhance their cows' productivity.

Is the profitability of Canadian tiestall farms associated with their performance on an animal welfare assessment?

In order for dairy producers to comply with animal welfare recommendations, financial investments may be required. In Canada, a new dairy animal care assessment program is currently being implemented under the proAction Initiative to determine the extent to which certain aspects of the Code of Practice are being followed and to assess the care and well-being of dairy cattle on farm. The aim of the current study was to evaluate the association between meeting the proAction animal-based and the electric trainer placement criteria and certain aspects of productivity and profitability on tiestall dairy farms. The results of a previous on-farm cow comfort assessment conducted on 100 Canadian tiestall farms were used to simulate the results of a part of the proAction Animal Care assessment on these farms. Each farm's productivity and profitability data were retrieved from the regional dairy herd improvement associations. Univariable and multivariable linear regressions were used to evaluate the associations between meeting these proAction criteria and the farms' average yearly: corrected milk production, somatic cell count (SCC), calving interval, number of breedings/cow, culling rate, prevalence of cows in third or higher lactation, and margins per cow and per kilogram of quota calculated over replacement costs. The association between milk production and the proAction lameness criterion was moderated through an interaction with the milk production genetic index which resulted in an increase in milk production per year with increasing genetic index that was steeper in farms that met the proAction lameness criterion compared with farms that did not. Meeting the proAction body condition score criterion was associated with reduced SCC and meeting the proAction electric trainer placement criterion was associated with SCC through an interaction with the farms' average SCC genetic index. The increase in SCC with increasing SCC genetic index was milder in farms that met this criterion compared with farms that did not. Farms that met the proAction electric trainer placement criterion had 4.6% more cows in their third or greater lactation. These results suggest that some associations exist between the productivity of Canadian tiestall farms and meeting several parameters of the proAction Animal Care assessment. Meeting these criteria is unlikely to impose any economic burden to the dairy industry as a whole.

Is the profitability of Canadian freestall farms associated with their performance on an animal welfare assessment?

Improving animal welfare on farm can sometimes require substantial financial investments. The Canadian dairy industry recently updated their Code of Practice for the care of dairy animals and created a mandatory on-farm animal care assessment (proAction Animal Care). Motivating dairy farmers to follow the recommendations of the Code of Practice and successfully meet the targets of the on-farm assessment can be enhanced by financial gain associated with improved animal welfare. The aim of the current study was to evaluate the association between meeting or not meeting several criteria from an on-farm animal welfare assessment and the farms' productivity and profitability indicators. Data from 130 freestall farms (20 using automatic milking systems) were used to calculate the results of the animal care assessment. Productivity and profitability indicators, including milk production, somatic cell count, reproduction, and longevity, were retrieved from the regional dairy herd improvement association databases. Economic margins over replacement costs were also calculated. Univariable and multivariable linear regression models were used to evaluate the associations between welfare and productivity and profitability indicators. The proportion of automatic milking system farms that met the proAction criterion for hock lesions was higher compared with parlor farms and lower for the neck lesion criterion. The proAction criterion for lameness prevalence was significantly associated with average corrected milk production per year. Average days in milk (DIM) at first breeding acted as an effect modifier for this association, resulting in a steeper increase of milk production in farms that met the criterion with increasing average DIM at first breeding. The reproduction and longevity indicators studied were not significantly associated with meeting or not meeting the proAction criteria investigated in this study. Meeting the proAction lameness prevalence parameter was associated with an increased profitability margin per cow over replacement cost by $236 compared with farms that did not. These results suggest that associations are present between meeting the lameness prevalence benchmark of the Animal Care proAction Initiative and freestall farms' productivity and profitability. Overall, meeting the animal-based criteria evaluated in this study was not detrimental to freestall farms' productivity and profitability.

A method of outdoor housing dairy calves in pairs using individual calf hutches.

Interest in housing dairy calves in groups is currently growing. Group housing using individual calf hutches, a resource already available in most dairy farms in North America, could provide a novel housing method that can be a simple way to implement group housing on farm. The main objective of this study was to determine whether pair housing dairy calves in hutches outdoors would result in similar weight gain and milk intake compared with individual housing in hutches. The study was designed to avoid competition for resources (including milk and solid feed, teat, bucket, outdoor space, and hutch) to test a setup that has the potential to maximize performance and calf growth. Secondary objectives were to document how calves in both treatments use their environment in terms of time spent and behaviors performed in each area, how paired calves interact, and the time they spend together. Single calves (n = 6/season) were housed in 1 hutch with an attached outdoor environment; paired calves (n = 6 pairs/season) were given twice the resources. Calves were fed up to 16 L/d of milk replacer. Daily milk intake and weekly weight gains were recorded. Behavioral observations were recorded live once per week for 5 (summer) or 4 (winter) nonconsecutive periods. Paired and single calves had similar weight gain (averaging from 1.1 to 1.3 kg/d across trials) and milk intake (averaging from 11.1 to 13.7 kg/d across trials), showing no difference in performance between treatments. Low occurrences of cross sucking (averaging from 0.1 to 0.4 bouts/h of observation per pen across trials) and displacements at the teat (0.8 to 1.4 bouts/h of observation per pen across trials) were found. All calves altered their behavior in some way to accommodate companions; paired calves were seen interacting and spending time together (i.e., lying in the same hutch), and in the summer trial single calves spent less time lying inside the hutch than paired calves, presumably to have visual access to other calves. The solution of mixed indoor and outdoor housing environments tested as part of this study showed that calves make use of all spaces provided to them in winter and in summer conditions while maintaining good performance. Housing calves in pairs using individual hutches can be a suitable alternative to housing calves individually in hutches outdoors.

Mortality and health treatment rates of dairy calves in automated milk feeding systems in the Upper Midwest of the United States.

Automated calf feeding systems are increasing in use across the United States, yet information regarding health and mortality outcomes of animals in these systems is limited. The objective of this study was to investigate the relationship between farm management practices, housing, and environmental factors with mortality and health treatment rates of preweaned dairy calves housed in groups with automated feeding systems. Farm records were collected for health treatments and mortality on 26 farms in the Upper Midwest of the United States. Relationships between factors of interest and mortality or treatment rate were calculated using a correlation analysis. Overall median annual mortality rate was 2.6 (interquartile range = 3.6; range = 0.24-13.4%), and 57% of farms reported mortality rates below 3%/yr. Farms that disinfected the navels of newborn calves had lower mortality rate (mean = 3.0%; standard error = 0.8; 78% of farms) than farms that did not disinfect (mean = 7.3%; standard error = 1.6; 22% of farms). Farm size (number of cows on site) was negatively associated [correlation coefficient (r) = -0.53], whereas the age range in calf groups was positively associated (r = 0.58) with mortality rate. Average serum total protein concentration tended to be negatively associated with annual mortality rate (r = -0.39; median = 5.4; range = 5.0-6.4 g/dL). Health treatment rate was positively associated with coliform bacterial count in feeder tube milk samples [r = 0.45; mean ± standard deviation (SD) = 6.45 ± 4.50 ln(cfu/mL)] and the age of calves at grouping (r = 0.50; mean ± SD = 5.1 ± 3.6 d). A positive trend was detected for coliform bacterial count of feeder mixing tank milk samples [r = 0.37; mean ± SD = 3.2 ± 6.4 ln(cfu/mL)] and calf age at weaning (r = 0.37, mean ± SD = 57.4 ± 9.6 d). Seasonal patterns indicated that winter was the season of highest treatment rate. Taken together, these results indicate that, although automated feeding systems can achieve mortality rates below the US average, improvements are needed in fundamental calf care practices, such as colostrum management and preventing bacterial contamination of the liquid diet and the calf environment.

Effect of following recommendations for tiestall configuration on neck and leg lesions, lameness, cleanliness, and lying time in dairy cows.

Cow comfort in tiestalls is directly affected by stall dimensions, for which some recommendations exist. To evaluate how well Canadian dairy farms with tiestalls complied with recommendations for stall dimensions, as well as the effect of compliance on cow comfort and cleanliness, we assessed lactating Holstein cows (n = 3,485) on 100 tiestall dairy farms for neck and leg lesions, lameness, and cleanliness and measured time spent lying down. Data on stall dimensions (width and length of the stall, position and height of the tie rail, length of the chain, and height of the manger curb) were recorded for each cow. The majority of cows were housed in stalls smaller than recommended. The prevalence of lesions and lameness was high (neck, 33%; knee, 44%; hock; 58%, lameness, 25%) and the prevalence of dirtiness was low (udder, 4%; flank, 11%; legs, 4%). Chains shorter than recommended increased the risk of neck, knee, and hock lesions. A tie rail further back in the stall than recommended increased the risk of neck, knee, and hock lesions and reduced the frequency of lying bouts and the risk of a dirty udder. A tie rail set lower than recommended decreased the risk of neck lesions and lameness and increased lying time and lying bout frequency. Stalls narrower in width than recommended increased the risk of neck injuries and lameness and reduced the daily duration of lying time and the risk of a dirty flank and legs. Stalls shorter in length than recommended increased the risk of knee lesions and reduced lying bout frequency and the risk of a dirty udder. The majority of farms do not follow recommendations for stall dimensions (with the exception of tie rail height), and the lack of compliance is associated with increased risk of lesions and lameness and can affect lying time. Recommended stall dimensions tend to reduce cleanliness, but the prevalence of dirty cows remains very low.

Technical note: Assessing lameness in tie-stalls using live stall lameness scoring.

Video stall lameness scoring (SLS) has been shown to be comparable to video locomotion scoring for evaluating lameness in dairy cows housed in tie-stalls and may be a more practical and easier method to measure lameness in a herd. We compared live SLS to video SLS and to live locomotion scoring. A total of 685 lactating cows subsampled from 27 commercial dairy herds were examined for lameness through live and video SLS. Cows scored with the live or video SLS system were scored for 4 behavioral indicators while still in their stall: weight shifting (shift), standing on the edge of the stall (edge), uneven weight bearing while standing (rest), and uneven weight bearing while moving from side to side (uneven). Two observers live scored and video scored for SLS. Lameness prevalence from video SLS and live SLS were similar (31 vs. 30%, respectively). Prevalence of the behavioral indicators varied from 0.59 to 58.2%. Sensitivity and specificity of live SLS was calculated using video SLS as the gold standard for lameness detection in tie-stalls. Sensitivity of live SLS was 0.83 and specificity was 0.94. False positives and false negatives for lameness were 14.4 and 16.8%, respectively. When comparing the prevalence of lameness measured through video or live SLS at the herd level, live SLS for lameness was correlated to video SLS (r = 0.91) with a Cohen's kappa coefficient of 0.79 (95% confidence limit = 0.73-0.84). Average exact agreement in the behavior indicators observed ranged from 80 to 100%. A subsample of 250 cows from 5 herds were scored for live SLS and live locomotion by a third observer. Intra- and interobserver reliability for live SLS and live locomotion scoring were found to have a kappa coefficient of 0.53 (95% confidence limit = 0.43-0.64) when determining a cow as lame through SLS or locomotion scoring. Live SLS was correlated with live locomotion scoring (r = 0.92). However, lameness prevalence was lower when using live SLS (28.4%) compared with locomotion scoring (38%). In summary, live SLS may be an acceptable method to replace video SLS to identify lame cows and rank tie-stall herds in terms of lameness prevalence without having to remove the cows from their stalls or view videos to score; however, it may underestimate lameness prevalence compared with locomotion scoring methods.

Factors associated with dairy calf health in automated feeding systems in the Upper Midwest United States.

Automated calf feeding systems are becoming more common on US dairy farms. The objective of this study was to evaluate calf health in these systems and to identify risk factors associated with adverse health outcomes on farms in the Upper Midwest United States. Over an 18-mo period on bimonthly farm visits to 38 farms, calves (n = 10,179) were scored for attitude, ear, eye, and nasal health, as well as evidence of diarrhea (hide dirtiness score of perianal region, underside of the tail, and tailhead). For all health score categories, a score of 0 represented an apparently healthy animal. Rectal temperatures were taken in calves scoring a ≥2 in any category, and those with a temperature >39.4°C were categorized as having a fever (n = 550). Associations were determined between farm-level variables and health scores to identify risk factors for higher (worse) scores. All health outcomes were associated with season of measurement, with fall and winter seasons increasing the odds of a high health score or detected fever. High bacterial counts measured in the milk or milk replacer were associated with increased odds for higher attitude and ear scores, and higher odds for calves having a detected fever. Higher peak milk allowance (L/d) was associated with lower hide dirtiness score, whereas a longer period of time (d) to reach peak milk allowance was associated with increased odds of higher scores for attitude, ear, eye, and hide dirtiness, as well as fever. Higher fat content in milk was associated with increased odds of high eye score. Less space per calf (m2/calf) was associated with higher ear and eye scores, whereas larger group sizes were associated with increased odds of higher nasal score and decreased odds of higher hide dirtiness score. Rectangular pen shape was associated with decreased odds of higher eye score. Absence of a positive pressure ventilation tube was associated with increased odds of having a calf detected with a fever. Based on these results, we hypothesize that these factors could be managed to improve health outcomes for dairy calves on automated feeding systems.

Producer estimates of prevalence and perceived importance of lameness in dairy herds with tiestalls, freestalls, and automated milking systems.

Lameness is one of the most important welfare and productivity concerns in the dairy industry. Our objectives were to obtain producers' estimates of its prevalence and their perceptions of lameness, and to investigate how producers monitor lameness in tiestall (TS), freestall with milking parlor (FS), and automated milking system (AMS) herds. Forty focal cows per farm in 237 Canadian dairy herds were scored for lameness by trained researchers. On the same day, the producers completed a questionnaire. Mean herd-level prevalence of lameness estimated by producers was 9.0% (±0.9%; ±SE), whereas the researchers observed a mean prevalence of 22.2% (±0.9%). Correlation between producer- and researcher-estimated lameness prevalence was low (r = 0.19) and mean researcher prevalence was 1.6, 1.8, and 4.1 times higher in AMS, FS, and TS farms, respectively. A total of 48% of producers thought lameness was a moderate or major problem in their herds (TS = 34%; AMS =53%; FS = 59%). One third of producers considered lameness the highest ranked health problem they were trying to control, whereas two-thirds of producers (TS = 43%; AMS = 63%; FS = 71%) stated that they had made management changes to deal with lameness in the past 2 yr. Almost all producers (98%) stated they routinely check cows to identify new cases of lameness; however, 40% of producers did not keep records of lameness (AMS = 24%; FS = 23%; TS = 60%). A majority (69%) of producers treated lame cows themselves immediately after detection, whereas 13% relied on hoof-trimmer or veterinarians to plan treatment. Producers are aware of lameness as an issue in dairy herds and almost all monitor lameness as part of their daily routine. However, producers underestimate lameness prevalence, which highlights that lameness detection continues to be difficult in in all housing systems, especially in TS herds. Training to improve detection, record keeping, identification of farm-specific risk factors, and treatment planning for lame cows is likely to help decrease lameness prevalence.

Lying times of lactating cows on dairy farms with automatic milking systems and the relation to lameness, leg lesions, and body condition score.

Lying down and resting are important for optimal cow health, welfare, and production. In comparison with free stall farms with a milking parlor, farms with automated milking systems (AMS) may place less constraint on how long cows can lie down. However, few studies report lying times on AMS farms. The aims of this study were to describe the variation in lying times of dairy cows in AMS farms and to understand how much of the variation in individual lying times is related to cow-level factors, including lameness, the presence of hock and knee lesions, and body condition score (BCS). We visited 36 farms in Canada (Quebec: n = 10; Ontario: n = 10; British Columbia: n = 4; and Alberta: n = 5), and the United States (Michigan: n = 7). Gait scores, presence of hock and knee lesions, and BCS were recorded for 40 Holstein cows from each herd. Parity and days in milk were retrieved from farm records. Lying time was recorded across 4d using accelerometers (n = 1,377). Multivariable analysis was performed. Of scored cows, 15.1% were lame (i.e., obviously limping; 203 of 1,348 cows). Knee lesions were found in 27.1% (340 of 1,256 cows) and hock lesions were found in 30.8% (421 of 1,366 cows) of the animals. Daily lying time varied among cows. Cows spent a median duration of 11.4 h/d lying down (25th-75th percentile = 9.7-12.9 h), with a lying bout frequency of 9.5 bouts/d (25th-75th percentile = 7.5-12 bouts/d) and a median bout duration of 71 min (25th-75th percentile = 58-87 min/bout). Lameness was associated with cows lying down for 0.6 h/d longer in fewer, longer bouts. Increased lying time was also associated with increased parity, later stage of lactation and higher BCS. Older cows (parity ≥ 3) spent about 0.5 h/d more lying down compared with parity 1 cows, and cows with BCS ≥ 3.5 lay down on average 1 h/d longer than cows with BCS ≤ 2.25. Hock lesions were associated with shorter lying times in univariable models, but no associations were found in the multivariable models. We concluded that only a small proportion of the variation between cows in lying time is explained by lameness, leg lesions, and BCS.

Cow- and farm-level risk factors for lameness on dairy farms with automated milking systems.

Lameness is a major concern to animal health and welfare within the dairy industry. Our objectives were to describe the prevalence of lameness in high-producing cows on farms with automated milking systems (AMS) and to identify the main risk factors for lameness at the animal and farm level. We visited 36 AMS farms across Canada and Michigan. Farm-level factors related to stall design, bedding use, flooring, and stocking rates were recorded by trained observers. Cows were scored for lameness, leg injuries, body condition (BCS), and body size (hip width and rump height; n=1,378; 25-40 cows/farm). Mean herd prevalence of clinical lameness was 15% (range=2.5-46%). Stall width relative to cow size and parity was found to be the most important factor associated with lameness. Not fitting the average stall width increased the odds of being lame 3.7 times in primiparous cows. A narrow feed alley [<430cm; odds ratio (OR)=1.9], obstructed lunge space (OR=1.7), a low BCS (OR=2.1 for BCS ≤2.25 compared with BCS 2.75-3.0), and presence of hock lesions (OR=1.6) were also identified as important risk factors for lameness. Only 1 of 36 farms had stalls of adequate width and length for the cows on their farm. For lameness prevention, it can be concluded that more emphasis needs be placed on either building stalls of appropriate width or selecting for smaller-framed cows that fit the existing stalls.

Calving management practices on Canadian dairy farms: Prevalence of practices.

Little information is available about current practices around calving in dairy cattle. The aim of this study was to describe calving management practices in the Canadian dairy industry related to housing, calving protocols, monitoring of parturition, and calving assistance. Information was gathered by in-person interviews from 236 dairy farms from 3 Canadian provinces (Alberta, Ontario, and Québec) with freestalls and an automatic milking system (n=24), freestalls with a parlor (n=112), and tiestalls (n=100). The most commonly used types of calving facilities were group calving pens (35%) followed by individual calving pens (30%). Tiestalls were used by 26% of all surveyed producers as their main type of calving area (49% of the tiestall, 7% of the freestall with parlor, and 13% of the automatic milking system farms). Written protocols related to calving were found on only 7% of the farms visited, and only 50% of those protocols were developed with a veterinarian. However, 90% of producers kept written records of calving difficulty. Monitoring of cows around calving occurred 5 times more often during the daytime (between morning and evening milking) compared with nighttime. Cameras were used to monitor cows around and during calvings on 18% of farms. Sixteen percent of producers vaginally palpated all animals during calving. Twenty-seven percent of producers interviewed assisted all calvings on their farms by pulling the calf, and 37% assisted all heifers at calving. According to the producers' reported perception, 93% of them had "a minor problem" or "no problem" with calving difficulties on their farms. This study provides basic data on current calving practices and identifies areas for improvement and potential targets for knowledge transfer efforts or research to clarify best management practices.

Associations between lying behavior and lameness in Canadian Holstein-Friesian cows housed in freestall barns.

Lying behavior is an important measure of comfort and well-being in dairy cattle, and changes in lying behavior are potential indicators and predictors of lameness. Our objectives were to determine individual and herd-level risk factors associated with measures of lying behavior, and to evaluate whether automated measures of lying behavior can be used to detect lameness. A purposive sample of 40 Holstein cows was selected from each of 141 dairy farms in Alberta, Ontario, and Québec. Lying behavior of 5,135 cows between 10 and 120 d in milk was automatically and continuously recorded using accelerometers over 4 d. Data on factors hypothesized to influence lying behavior were collected, including information on individual cows, management practices, and facility design. Associations between predictor variables and measures of lying behavior were assessed using generalized linear mixed models, including farm and province as random and fixed effects, respectively. Logistic regression models were used to determine whether lying behavior was associated with lameness. At the cow-level, daily lying time increased with increasing days in milk, but this effect interacted with parity; primiparous cows had more frequent but shorter lying bouts in early lactation, changing to mature-cow patterns of lying behavior (fewer and longer lying bouts) in late lactation. In barns with stall curbs >22 cm high, the use of sand or >2 cm of bedding was associated with an increased average daily lying time of 1.44 and 0.06 h/d, respectively. Feed alleys ≥ 350 cm wide or stalls ≥ 114 cm wide were associated with increased daily lying time of 0.39 and 0.33 h/d, respectively, whereas rubber flooring in the feed alley was associated with 0.47 h/d lower average lying time. Lame cows had longer lying times, with fewer, longer, and more variable duration of bouts compared with nonlame cows. In that regard, cows with lying time ≥ 14 h/d, ≤ 5 lying bouts per day, bout duration ≥ 110 min/bout, or standard deviations of bout duration over 4 d ≥ 70 min had 3.7, 1.7, 2.5, and 3.0 higher odds of being lame, respectively. Factors related to comfort of lying and standing surfaces significantly affected lying behavior. Finally, we inferred that automated measures of lying behavior could contribute to lameness detection, especially when interpreted in the context of other factors known to affect lying behavior, including those associated with the individual cow (e.g., parity and stage of lactation) or environment (e.g., stall surface).

Prevalence of and risk factors for hock and knee injuries on dairy cows in tiestall housing in Canada.

Leg injuries on dairy cows are a common and highly visible welfare concern on commercial dairy farms. With greater attention being placed on food animal welfare and limited research being conducted on tiestall farms, this study aimed to identify prevalence and risk factors for hock and knee injuries on dairy cows housed in tiestall barns in Ontario (n=40) and Quebec (n=60). A sample of 40 cows was purposively selected per farm and several animal- and farm-based measures were taken. Both hocks and both knees on each cow were scored as injured (presence of lesions or swelling) or not injured (no alterations or hair loss), and the highest score of each of the 2 knees and the 2 hocks was considered the cow's hock or knee score. Possible animal- and farm-based risk factors were incorporated into 2 separate multivariable logistic models for hock injuries and knee injuries respectively at the cow level. Mean (±SD) percentage of cow with hock injuries per farm was found to be 56±18% and mean percentage of knee injuries per farm was found to be 43±23%. Animal-based factors found to be associated with a greater odds of hock injuries at the cow level were increased days in milk (DIM), lower body condition score (BCS), lameness, higher parity, higher cow width, median lying bout duration, and median number of lying bouts. Environmental factors found to be associated with hock injuries at the cow level were province, stall width, tie rail position, stall base, chain length, and age of stall base. Animal-based factors found to be associated with knee injuries at the cow level were DIM, BCS, and median lying time. Environmental factors found to be associated with knee injuries at the cow level were stall width, chain length, province, stall base, and bed length. Quadratic and interaction terms were also identified between these variables in both the hock and knee models. This study demonstrates that hock and knee injuries are still a common problem on tiestall dairy farms in Canada. Several animal- and housing-based factors contribute to their presence. Further research to confirm causal relationships between these factors would help identify the cause of knee and hock injuries and determine how to best reduce the incidence of injuries in cows on commercial tiestall dairy farms in Canada.

An assessment tool to help producers improve cow comfort on their farms.

Effective management and an appropriate environment are essential for dairy cattle health and welfare. Codes of practice provide dairy producers with best practice guidance for the care and handling of their cattle. New Canadian recommendations have been established for the dairy industry. The objectives of this study were to develop an on-farm assessment tool that helps producers assess how well they are meeting their code of practice and that identifies management and environment modifications that could improve dairy cow comfort on their farms. The assessment tool addressed critical areas of dairy cow comfort, including accommodation and housing (stall design, space allowance, stall management, pen management, milking parlor, and transfer alleys), feed and water (body condition scoring, nutrition), and health and welfare (lameness, claw health, and hoof-trimming). Targets of good practices were identified from the requirements and recommendations of the code of practice. Each farm received a score for each target, ranging from 0 (target not reached) to 100 (target reached). One hundred tiestall and 110 freestall farms were surveyed in 3 provinces of Canada (Quebec, Ontario, and Alberta). The duration of the assessment, in 2 visits lasting, on average, 8 and 9h (range between freestall and tiestall farms) and 4 and 4.1h, was beyond the targeted 3 to 4h due mainly to the animal-based measures; strategies to reduce the duration of the assessment were discussed. Standard operating procedures were developed to ensure consistency in measuring and recording data. Periodical checks were conducted by trainers to ensure all 15 assessors remained above target agreement of weighted kappa ≥0.6. Average scores for all critical areas ranged from 25 to 89% for freestall farms and from 48 to 95% for tiestall farms. These scores need to be considered with caution when comparing farms because scores could not always be calculated the same way between housing systems. An evaluation report was provided and discussed with each producer, identifying strengths and areas for improvement that could benefit dairy cow comfort on their farms. The producers were convinced of the effectiveness of our tool for assessing cow comfort (freestall: 86%; tiestall: 95%) and in assisting them to make decisions for improvements (freestall: 83%; tiestall: 93%). Our cow comfort assessment tool served as background material for the Dairy Farmers of Canada animal care assessment program.

Providing supplementary milk to suckling dairy calves improves performance at separation and weaning.

Dam rearing can provide health and welfare benefits, but separation and weaning are major welfare challenges. We investigated whether access to an additional source of milk from an automatic milk feeder (AMF) would improve weight gains after separation and weaning. During the first 6wk of life (dam phase), calves were assigned to 1 of 3 treatments using a parallel group design with repeated measures: nursing (n=10) and combined (n=10) calves could suckle from their dams at night (between 2000 and 0800h), and combined calves also had access to 12 L of milk/d accessible 24h/d from an AMF. Milk feeder calves (n=10) also had access to an AMF 24h/d and were housed with the dam at night but were prevented from suckling by an udder net. Separation from the dam occurred after 6wk in 2 phases with decreasing contact between cow and calf: partial separation (duration 4d) and total separation (duration 3d). At separation, all calves were granted access to 12 L of milk 24h/d from the AMF until weaning began at 7wk of age. We hypothesized that access to an AMF during the dam phase would result in less weight loss at separation and weaning compared with calves that had been nutritionally dependent upon the cow (i.e., nursing calves). Calf weight gain during the dam phase averaged (±SD) 1.1±0.26kg/d and did not vary with treatment. Combined calves drank less milk from the AMF compared with milk feeder calves during the dam phase (mean ± SEM daily milk intake: 1.1±0.38 vs. 8.2±0.34 L/d) and tended to drink less during partial separation (6.7±1.28 vs. 9.8±1.02 L/d), but milk intake from the AMF did not differ between these treatments in the later phases. During the same phases, nursing calves consumed less milk from the AMF than the other treatments; of the 10 calves, 6 did not use the AMF (consuming <1.5 L/d) after the dam phase. After separation, nursing calves gained less weight than calves in both the milk feeder and combined treatments (0.8±0.16 vs. 1.2±0.08kg/d). Calves using the AMF after separation (n=23; 4 nursing calves, 9 combined calves, and 10 milk feeder calves) had a higher average daily gain compared with calves that did not (n=7; 6 nursing calves and 1 combined calf; 1.2±0.07 vs. 0.6±0.21kg, respectively). In conclusion, use of the AMF after separation varied, but providing an additional milk source reduced nutritional dependency on the dam, improving calf performance at weaning and separation.

Prevalence of lameness and associated risk factors in Canadian Holstein-Friesian cows housed in freestall barns.

Lameness is a severe welfare problem and a production-limiting disease in dairy farming. The objectives of this study were to determine prevalence of lameness and investigate cow- and herd-level factors associated with lameness in dairy cows housed in freestall barns in 3 Canadian provinces. A purposive sample of 40 Holstein-Friesian cows was selected from each of 141 dairy farms in Québec, Ontario, and Alberta. In total, 5,637 cows were scored once for lameness (presence of limping when walking). Data collected included information on individual cows (hock lesions, claw length, body condition score, parity, days in milk, and milk production), management practices (floor and stall cleaning routine, bedding routine, and footbath practices), and facility design (stall dimensions, stall base and bedding type, width of feed alley, flooring type, and slipperiness) hypothesized to be risk factors for lameness. Multilevel mixed logistic regression models were constructed (including farm as a random effect and province as a fixed effect). Herd-level lameness prevalence ranged from 0 to 69% (mean = 21%). Lameness prevalence increased with increasing parity; compared with first parity, cows in parity 2, 3, and ≥ 4 had 1.6, 3.3, and 4 times, respectively, higher odds of being lame. Furthermore, the odds of lameness were 1.6 times greater in cows with low body condition score (≤ 2.5) than in cows with a higher body condition score. In addition, injured hocks and overgrown claws were associated with 1.4- and 1.7-fold increased odds of being lame, respectively, whereas every 1 kg increase in daily milk production was associated with a 3% decrease in the odds of being lame. Lameness prevalence was higher in herds with ≤ 100 cows, but lower in barns with a sand or dirt stall base, or with bedding ≥ 2 cm deep. Cows exposed to very slippery floors had 2 times the odds of being lame compared with cows exposed to nonslippery floors. We attributed the wide range of lameness prevalence to the great variability in facilities and management practices among farms. Finally, we inferred that the prevalence of lameness could be decreased by improving management of multiparous, thin, or injured cows and by adopting management practices intended to improve cow comfort, namely the floor's slip resistance and the stall's lying surface.