Attitudes and professional values of veterinarians and veterinary students towards positive welfare states for dairy cattle.

Research that involves agricultural animal welfare has typically aimed to improve welfare by decreasing disease, distress, and pain. Positive welfare does not necessarily occur with the absence of suffering but in combination with opportunities for behaviors or affective states desired by animals. Our objectives were to describe Canadian bovine veterinarians' and veterinary students' attitudes, professional normative values, and perceived ability to promote positive welfare for dairy cows, and to explore participants' provided rationale. With an online cross-sectional survey, Canadian veterinary practitioners (n = 78) and veterinary students (n = 148) were asked, on a 7-point Likert scale, about their attitudes, perceived professional normative values, and perceived ability of veterinarians to promote positive welfare for dairy cows. We used an applied thematic analysis approach within the qualitative description methodology to analyze participants' open-ended text responses. Quantitatively, participants had very favorable attitudes (mean ± SE; 6.3 ± 0.04) and perceived favorable values (5.7 ± 0.06) in the veterinary community toward positive welfare opportunities for dairy cows. Three themes were identified to explain the professional normative values: influences from within the veterinary profession, influences from outside the veterinary profession, and personal views of participants. Participants were confident that veterinarians could suggest positive welfare opportunities for dairy cows (6.1 ± 0.06) but were uncertain that the decision to suggest these opportunities to producers was within a veterinarian's control (4.3 ± 0.11) and were not confident that implementation of positive welfare opportunities was under a veterinarian's control (2.1 ± 0.07). Three themes were identified to explain the barriers to veterinarians promoting positive welfare opportunities for dairy cows: not practical to implement, resistance to change, and concern for the animal. Participants stated that many positive welfare opportunities were impractical or expensive to implement. We conclude that positive attitudes and positive professional values exist in the veterinary community toward positive welfare for dairy cows but that much uncertainty exists regarding a veterinarian's ability to influence change to current practices.

Associations between feeding behaviors collected from an automated milk feeder and disease in group-housed dairy calves in Ontario: A cross-sectional study.

The adoption of automated milk feeders and group housing of preweaning dairy calves has become more common in Canada; however, disease detection in group-housed calves remains a challenge. The aim of this cross-sectional study was to assess whether feeding behavior data collected from a single point in time could be used to aid in the detection of neonatal calf diarrhea (NCD), bovine respiratory disease (BRD), and general disease, in preweaning group-housed calves being fed via an automated milk feeder. The data used was collected in an earlier study. A total of 8 dairy farms recruited from an online survey of calf-management practices were enrolled into the study. There was a total of 523 observations with 130 events of NCD, 115 events of BRD, and 210 events of general disease. Each farm was visited once in each of the fall, winter, spring, and summer, when the calves' health was scored, and the data were collected from the automated milk feeders. Mixed linear regression models were used to identify associations between feeding behavior data (milk consumption, time spent at the feeder, drinking speed, and the number of rewarded and unrewarded visits) and the presence of NCD, BRD, or general disease (having one or more of NCD, BRD, or umbilical infection), on the day of health scoring. Generalized linear mixed models were used to analyze the percentage of milk the calf consumed from their daily milk allotment. Calves with BRD consumed 63% less of their daily allotment of milk, had 2 fewer unrewarded visits to the automated milk feeder, and drank milk 152 mL/min slower compared with calves without BRD. Calves with NCD consumed 57% less of their daily milk allotment, consumed 758 mL less per day, and drank 92 mL/min slower than calves compared with calves without NCD. Calves with general disease drank 50% less of their daily milk allowance, consumed 496 mL less per day, drank 80 mL/min slower, and had 2 fewer unrewarded visits to the automated milk feeder, when compared with calves without disease. No significant associations were found between the presence of NCD, BRD, or general disease and time spent at the feeder or number of rewarded visits. Sensitivity and specificity values for disease identification were low when evaluating the feeding behaviors individually, so parallel testing was completed. To do so, if any significant feeding behavior was below the optimal cut point for disease detection as determined using a ROC curve, the calf was considered positive for disease and the sensitivity and specificity were recalculated. Parallel testing resulted in a sensitivity of 0.82, 0.78, and 0.84, and a specificity of 0.26, 0.23, and 0.21, for BRD, NCD, and general disease, respectively. This suggests that automated milk feeders may serve as a useful preliminary tool in the detection of diseased calves. For example, producers could use feeding behavior data to identify calves requiring further inspection; however, they should not use feeding behavior data as a sole disease detection method.

Dairy farmers' expectations and receptivity regarding animal welfare advice: A focus group study.

Discussion and incorporation of best practices for animal welfare have been increasing in research, and in commercial operations, including through welfare assessment initiatives. The aim of this study was to explore dairy farmers' perceptions about being approached and receiving advice about animal welfare (i.e., lameness, hock injuries, and disbudding practices). It is useful for dairy consultants, researchers, or animal welfare assessment programs to gain an in-depth understanding of farmers' expectations when broaching the subject of animal welfare issues to facilitate communication about what can be perceived as a sensitive topic. We collected qualitative data using a focus group methodology. Five focus groups of farmers (n = 36 in total), took place in Ontario, Canada. Discussions were audio-recorded and transcribed verbatim. Participant age ranged from 21 to 80 yr (median = 47). Represented herd size ranged from 25 to 550 milking cows (median = 75). Farm type included free stall (n = 14) and tie stall (n = 22). Rigor was incorporated by using systematic thematic analysis: transcripts were coded line by line, and codes were categorized and then expanded and collapsed into themes, which were further refined to reflect farmer perceptions in a thematic map. Thematic analysis of the focus group discussions suggested 6 major themes related to farmers' receptivity to and expectations of animal welfare advice. Themes 1 to 4 provided insights into what farmers expected from those who were broaching topics: (1) an established relationship with the farmer; (2) expertise in dairy care/welfare; (3) prevention of "barn blindness"; and (4) provision of animal care services before and after welfare issues are broached. Theme 5 helped determine how welfare topics should be broached: the communication approach. Theme 6 identified who farmers feel should broach animal welfare topics on farm. Focus group discussions also provided insights into potential disconnects between farmer and veterinary expectations about animal welfare issues during herd health visits. Those who have established relationships with farmers are better received and are expected to broach welfare issues, especially if they are perceived to be an expert in animal care and welfare, and if they communicate the issue tactfully and work with the farmer to establish a plan of action.

Training method for animal-based measures in dairy cattle welfare assessments.

Quantitative assessments of animal welfare are increasingly being used in the dairy industry. It is important to have good precision and accuracy within and among assessors. This study explored the effectiveness of a 3-d training workshop for animal-based measures (ABM) of welfare in dairy cows, in which 14 people were trained to evaluate 6 ABM, specifically hock injuries (HI), lameness (LM), body condition score (BCS), and udder, flank, and leg cleanliness (collectively CLN). All scoring systems were modified to a dichotomous outcome, acceptable or unacceptable. Acceptable HI included no swelling or hair loss, unacceptable HI included swelling or scab; acceptable BCS was >2 on a 5-point scale, unacceptable BCS was ≤2. Acceptable CLN was up to minor splashing, unacceptable CLN was distinct plaques to a solid manure plaque. Lameness was evaluated using locomotion score or in-stall lameness score (SLS) in tiestalls; unacceptable LM was ≥3 (lameness score) on a 5-point scale, where 3 equals mild lameness or ≥2 of 4 behavioral in-stall lameness score indicators were detected. Classroom instruction took place on d 1 of training. Day 2 consisted of group assessment of LM (n = 25 cows), and HI, CLN, and BCS (n = 30 cows), and individual assessment of HI, CLN, and BCS (n = 20 cows) were performed. Day 3 included individual assessments of HI, CLN, and BCS (n = 33 cows), and individual video assessment of LM (n = 27 cows). An additional training video for LM was sent to trainees 3 wk after the workshop, and another follow-up assessment of LM took place via video (n = 37 cows). Repeatability and accuracy of the trainees was assessed using Fleiss's κ (FK) and Byrt's κ (BK) to examine group-level inter-rater agreement and expert-trainee agreement, respectively. The kappa systems use a scale of poor (<0), slight (0.01 to 0.20), fair (0.21 to 0.40), moderate (0.41 to 0.61), substantial (0.61 to 0.80), or almost perfect (0.81 to 1.00). At the conclusion of the workshop, FK was 0.66 for HI and 0.43 for LM, and BK mean (and range) was 0.85 (0.63 to 1.00) for HI and 0.66 (0.56 to 0.85) for LM. Each trainee achieved perfect agreement for BCS [BK mean = 1.00 (1.00 to 1.00)] and each trainee achieved almost perfect agreement for CLN [BK mean 0.90 (0.82 to 0.94)]. After the follow-up video and 3 wk of experience, trainees achieved a FK of 0.66 and a BK mean of 0.74 (0.62 to 0.89) for LM. In conclusion, multiple assessors can achieve substantial agreement for ABM with adequate training.

Clinical and metabolic indicators associated with early mortality at a milk-fed veal facility: A prospective case-control study.

Antimicrobial use and resistance, in combination with high levels of mortality, are important challenges facing the veal industry. To improve both the economic sustainability of the industry and animal welfare, measures need to be taken to explore and address reasons for these challenges. Health status at arrival may be an important predictor of calf mortality because substantial mortality occurs early in the growing period on veal operations. The objective of this observational case-control study was to identify clinically measurable variables and metabolic indicators associated with mortality in the first 21 d following arrival at a veal facility. Calves were evaluated using a standardized health scoring system, blood was collected, calves were weighed, and the supplier of the calf was recorded at arrival. The calves were followed until death or 21 d after arrival. Cases were defined as calves that died ≤21 d following arrival. Two controls for every case were randomly selected from calves that survived >21 d, arrived on the same day, and were housed in the same barn as cases. Stored serum harvested at arrival from cases and controls was submitted for measurement of concentrations of nonesterified fatty acids, ß-hydroxybutyrate, glucose, cholesterol, urea, haptoglobin, and immunoglobulin G. A conditional logistic regression model was built to evaluate factors associated with mortality ≤21 d following arrival. A total of 4,825 calves were evaluated from November 2015 to September 2016. The mortality risk in the first 21 d was 2.8%, giving 135 cases, which were compared with 270 controls. Six variables were significant in the final multivariable model. Calves with a slightly enlarged navel with slight pain or moisture, and those with severe dehydration had increased odds of mortality ≤21 d following arrival. Drover-derived calves, calves that weighed more, and calves that had higher concentration of immunoglobulin G or cholesterol at arrival were less likely to die. The results demonstrate that calves at elevated risk for early mortality can be identified at arrival using both health and hematological factors. Early recognition of high-risk calves may allow for an intervention that could result in improvement in survival rates; however, prevention of these abnormalities before arrival at veal facilities needs to be further explored.

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.

Risk factors associated with mortality at a milk-fed veal calf facility: A prospective cohort study.

The veal industry experiences calf losses during the growing period, which represents a challenge to animal welfare and profitability. Health status at arrival may be an important predictor of calf mortality. The objectives of this prospective cohort study were to describe the health status of calves arriving at a veal farm and determine the risk factors associated with early and late mortality. Using a standardized health scoring system, calves were evaluated immediately at arrival to a commercial milk-fed veal facility in Ontario, Canada. Weight at arrival and supplier of the calf were recorded. The calves were followed until death or the end of their production cycle. Two Cox proportional hazard models were built to explore factors associated with early (≤21 d following arrival) and late mortality (>21 d following arrival). A total of 4,825 calves were evaluated from November 2015 to September 2016. The overall mortality risk was 7%, with 42% of the deaths occurring in the first 21 d after arrival. An abnormal navel, dehydration, housing location within the farm, arriving in the summer, and the presence of a sunken flank were associated with increased hazard of early mortality. Drover-derived calves and calves with a greater body weight at arrival had lower hazard of early mortality. Housing location within the farm, being derived from auction facilities, and an abnormal navel were associated with higher hazard of late mortality. These results demonstrate that risk factors for mortality can be identified at arrival, which represents a potential opportunity to selectively intervene on these calves to reduce mortality. However, methods of preventing the development of these conditions before arrival need to be explored and encouraged to improve the welfare of the calves entering the veal industry.

Calf management risk factors on dairy farms associated with male calf mortality on veal farms.

The objective of this cross-sectional herd-level study was to assess the association of calf management practices on source dairy farms with mortality risk on veal farms. From April to October 2016, 52 source dairy farms supplying male calves to 2 veal operations were visited once. A questionnaire was administered that covered all areas of calf management, calves between 1 and 10 d of age were examined using a standardized health scoring system, and blood was taken to evaluate passive transfer of immunoglobulins. The mortality risk for calves from each dairy farm was calculated based on the number of male calves sold from the dairy farm and that died during 2016 at the veal operations. The mean mortality risk was calculated for both veal farms and, based on the veal facility-adjusted mortality risk, dairy farms were classified as high- or low-mortality source farms. Using the information gathered at the 52 source dairy farms, a logistic regression model was used to assess factors associated with being a high-mortality source farm. Suppliers to veal farm 1 had a mean mortality risk of 9.6% and suppliers to veal farm 2 had a mean mortality risk of 4.2%. The lower mortality risk at veal farm 2 was partially influenced by a shorter period of observation. Of the 182 calves examined during the single visit to the source dairy farms, 41% of male calves and 29% of female calves had at least one identifiable health abnormality. The risk of failure of passive transfer on source dairy farms was low, with only 13% of calves tested having <10 mg of IgG/mL of serum. The subset of calves examined at the source dairy farm was not followed prospectively to the veal farms. Using a tube feeder or pail to feed colostrum, bedding male calves on wood shavings or chopped straw at the source dairy farm, and the herd veterinarian not routinely and actively inquiring about the health and performance of calves during regular herd visits were significantly associated with the farm being classified as a high-mortality source dairy farm. Checking the calving pen at an interval of every 3 h or more during the day was associated with a lower probability of being classified as a high-mortality source dairy farm. The results of this study suggest that there are management practices on the source farm that contribute to the risk of mortality on veal farms.

Validation of commercial luminometry swabs for total bacteria and coliform counts in colostrum-feeding equipment.

A sufficient quantity and quality of colostrum must be fed quickly to the newborn calf while minimizing bacterial contamination. Adenosine triphosphate bioluminescence swabs offer a potential rapid on-farm alternative to assess bacterial contamination of colostrum. The objective of this study was to validate the Hygiena (Camarillo, CA) AquaSnap Total (AS), SuperSnap (SS), PRO-Clean (PC), and MicroSnap Coliform (MS) swabs as well as visual hygiene assessment for detection of elevated bacterial counts in or on colostrum-feeding equipment. From April to October 2016, 18 esophageal tube feeders, 49 nipple bottles, and 6 pails from 52 dairy farms in Ontario were evaluated for cleanliness. Following visual hygiene assessment, sterile physiological saline (15 mL) was poured into each piece of equipment, mixed for 2 min to ensure total surface coverage, and poured into a sterile collection container through the feeding end. The fluid was split into equal aliquots, with one being evaluated by conventional culture and the other evaluated using the luminometry swabs. Nonparametric receiver operator curves were used to compare the test performance of the luminescence reading (relative light units; RLU) from each type of swab to conventional bacterial culture. The area under the curve comparing the AS swab to total bacterial count (cut point >100,000 cfu/mL) was 0.89, and using a cut point of 631 RLU correctly classified 84% of samples with a sensitivity of 88% and a specificity of 77%. The area under the curve comparing the MS swab to total coliform count (cut point >10,000 cfu/mL) was 0.85, and using a cut point of 44 RLU correctly classified 89% of samples with a sensitivity of 83% and a specificity of 90%. Visual hygiene assessment, PC and SS swabs were not reliable indicators for feeding equipment cleanliness. The results suggest that the AS and MS swabs can be used as an alternative to traditional laboratory bacterial counts to evaluate cleanliness of colostrum-feeding equipment.

Management practices for male calves on Canadian dairy farms.

Morbidity, mortality, and antimicrobial use and resistance are major concerns in the rearing of male dairy calves, so information to support disease prevention is important. The objective of this cross-sectional study was to describe management practices associated with the care of male calves during their first days of life on Canadian dairy farms. A survey was completed by dairy producers across Canada between March 1 and April 30, 2015. The survey included 192 questions covering producer background, farm characteristics, biosecurity practices, disease prevalence, calf health, animal welfare, lameness, milking hygiene, reproduction, and Internet and social media use. A total of 1,025 surveys were completed online, by telephone, or by mail, representing 9% of all dairy farms in Canada. Five percent of respondents (n = 49) answered that they had euthanized at least 1 male calf at birth in the previous year, and blunt force trauma was commonly used in these cases. The majority of respondents always fed colostrum to male calves; however, 9% (n = 80) did not always feed colostrum. Almost 40% (n = 418) of respondents reported always dipping the navels of male calves, 12% (n = 123) vaccinated male calves, and 17% (n = 180) did not provide the same quantity of feed to male calves as heifer calves. The care of male calves differed greatly depending on the geographical region of the respondents. However, some regional effects may be confounded by economic conditions and the logistics of marketing male dairy calves in different parts of the country. Herd size was another important variable in many aspects of the management of male calves on dairy farms. Larger herd sizes were more likely to use an appropriate method of euthanasia at birth but were less likely to always feed colostrum to their male calves or feed them the same as female calves. Familiarity with the Code of Practice for the Care and Handling of Dairy Cattle (National Farm Animal Care Council) by respondents was associated with better care of male calves on dairy farms. The results of this survey suggest that the treatment of male dairy calves on Canadian dairy farms varies and that there are opportunities to improve the health management of male calves on the farms of origin.

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.

Systematic early obstetrical assistance at calving: II. Effects on dairy heifer calf growth, health, and survival to weaning.

Good calving management should not only ease the transition of cows into lactation, but also contribute to providing healthy replacement animals for the herd. Difficulty during parturition has been found to be detrimental to the offspring. Because of the association of obstetrical intervention with undesirable outcomes, the general management recommendation for calving is to let cows give birth unassisted whenever possible. Unfortunately, very few studies have investigated the effects of planned early assistance during calving, regardless of whether or not another problem exists. To investigate the effects of early assistance during apparently normal calvings, a clinical trial was conducted on 257 Holstein cows. They were observed through the second stage of calving, and before calving they were divided randomly between 2 assigned interventions: not assisted or early assistance during the second stage of parturition. After calving, the animals were classified into 4 actual calving intervention groups: too quick to be assisted, not assisted, early assistance, and late assistance (for cows in the not assisted group that did not calve unassisted within the 1 h maximum time allowed). Early assistance was given 15 min after first sight of both front hooves of the calf and done using human force only. Heifer calves (n=129) born from enrolled dams were followed until weaning to assess the effect of assigned and actual calving interventions on their growth, health, and survival. Heifer calves' weight at birth was positively associated with weight at 7 wk, but the effect varied by assigned and actual intervention. As a routine management practice, giving early assistance during calving to dairy cows did not influence average daily gain, health, or survival in dairy heifer calves up to weaning at 7 wk of age.

Systematic early obstetrical assistance at calving: I. Effects on dairy calf stillbirth, vigor, and passive immunity transfer.

A critical time for dairy cattle is the perinatal period. Good calving management is critical to reduce periparturient losses and ensure the health of the offspring. Generally, it has been recommended that cows be allowed to calve unassisted when possible, but very few studies have been published that support or refute this general guideline. To investigate the effect of early assistance, a clinical trial enrolled 257 Holstein cows that were observed through the second stage of calving and assigned randomly to 1 of 2 calving interventions: not assisted (NA) or early assistance (EA) during the second stage of parturition. Early assistance was given 15min after the first sight of both front hooves of the calf and done using only human force. After calving, the animals were classified into 4 actual calving intervention groups: too quick to be assisted (TQ), NA, EA, and late assistance (LA; for cows in the NA group that did not calve unassisted within the 1h maximum time frame allowed). Giving early assistance to cows during calving as a routine management practice (assigned intervention) did not negatively influence calves' stillbirth risk, vigor at birth, or transfer of passive immunity. Calves in the LA intervention group had significantly greater odds of stillbirth than calves in the NA and EA groups, respectively. Calves in the LA group also had significantly worse vigor at birth than calves in the TQ, NA, or EA groups. Early assistance given at calving to cows that did not present signs of calving difficulties did not adversely affect calves' likelihood of being stillborn, vigor at birth, or transfer of passive immunity.

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.

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).

Effect of feed type and method of presentation on feeding behavior, intake, and growth of dairy calves fed a high level of milk.

The objective of this study was to assess the effect of different feed types and method of feed presentation in the first 12 wk of life on the feeding behavior, intake, and growth of calves fed a high milk level. Forty-eight neonatal Holstein calves were individually housed and randomly assigned to 1 of 4 treatments and fed solid feed ad libitum: silage-based total mixed ration (TMR), concentrate (CON), and chopped hay and concentrate presented in 2 manners: mixed (MIX) or separate (SEP). All calves were offered 12 L/d of acidified milk replacer (1.8 kg of dry matter) until d 38 at which time step-down weaning by 1 L/d began. At d 50 calves no longer received milk, and all calves on SEP and CON treatments were offered the MIX diet until the end of the trial, whereas TMR and MIX calves did not change feeds. Feed intakes were recorded daily, and calves were weighed twice per week. Rumination time was observed on the last 3 d of alternate weeks (wk 3, 5, 7, 9, and 11) for 1h beginning at 1500 h. Time spent feeding was determined for the last 2 d of alternate weeks. In the preweaning stage (d 1-37) average daily gain was similar for all calves (1.1 kg/d). The TMR calves had lower average daily gain than calves on the other 3 treatments during both the weaning (d 38-49; 0.2 vs. 0.7 kg/d) and postweaning (d 50-84; 0.5 vs. 1.2 kg/d) stages. This result is related to the lower dry matter intake of calves fed TMR in comparison with MIX, SEP, and CON calves in the weaning (0.2 vs. 0.5 kg/d) and postweaning (1.8 vs. 2.8 kg/d) stages. Given dry matter content of the feeds (TMR=52%, other diets=89%), the as-fed intake of the calves was similar across treatments in all 3 stages. Calves offered hay in addition to concentrate showed no difference in concentrate intake in the first 7 wk of life. Interestingly, TMR calves spent more time feeding during the postweaning stage than MIX, SEP, and CON calves (308 vs. 194 min/d) and exhibited a slower feeding rate postweaning (5.9 vs. 14.4 g of dry matter per minute). It appears that during weaning, and postweaning, calves fed TMR were attempting to maximize their nutrient intake but were unable to match that of calves in other treatments because of the high moisture content of their feed, and thus were unable to achieve similar average daily gain. Additionally, growth and total intake throughout the preweaning and weaning stages were similar for calves fed chopped hay along with concentrate and those not offered hay, suggesting no detrimental effect of feeding forage.

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.

Validation of triaxial accelerometers to measure the lying behaviour of adult domestic horses.

Examining the characteristics of an animal's lying behaviour, such as frequency and duration of lying bouts, has become increasingly relevant for animal welfare research. Triaxial accelerometers have the advantage of being able to continuously monitor an animal's standing and lying behaviour without relying on live observations or video recordings. Multiple models of accelerometers have been validated for use in monitoring dairy cattle; however, no units have been validated for use in equines. This study tested Onset Pendant G data loggers attached to the hind limb of each of two mature Standardbred horses for a period of 5 days. Data loggers were set to record their position every 20 s. Horses were monitored via live observations during the day and by video recordings during the night to compare activity against accelerometer data. All lying events occurred overnight (three to five lying bouts per horse per night). Data collected from the loggers was converted and edited using a macro program to calculate the number of bouts and the length of time each animal spent lying down by hour and by day. A paired t-test showed no significant difference between the video observations and the output from the data loggers (P=0.301). The data loggers did not distinguish standing hipshot from standing square. Predictability, sensitivity, and specificity were all >99%. This study has validated the use of Onset Pendant G data loggers to determine the frequency and duration of standing and lying bouts in adult horses when set to sample and register readings at 20 s intervals.

Associations of serum haptoglobin in newborn dairy calves with health, growth, and mortality up to 4 months of age.

The objective of this research was to investigate factors associated with serum haptoglobin (Hp) levels in newborn calves. In addition, the associations between serum Hp levels in newborn calves with growth, morbidity, and mortality in calves <4 mo of age were investigated. A total of 1,365 Holstein heifer calves from 15 dairy farms were enrolled in this study from January to December, 2008. Following calving, a birth record was completed, including information on the calving event, colostrum administration, and other details. During weekly farm visits, each calf was assessed at 1 to 8 d, 15 to 21 d, 36 to 42 d, and 90 to 120 d of age. At these sampling times, each calf was assessed using a standardized clinical score for general health, and height and weight were measured. At 1 to 8 d of age, a blood sample was collected to measure serum total protein and Hp concentrations. Treatment events and death loss were recorded throughout the study by the farm staff. Serum Hp concentration in the first week of life was not significantly associated with the degree of calving difficulty. However, serum Hp was higher in calves with a higher rectal temperature and depressed attitude at the first sampling time. Furthermore, the association between serum Hp and the severity of nasal discharge varied by age at first sampling time. Calves with higher Hp in their first week of life had significantly higher total health scores throughout the entire sampling period. Haptoglobin was not significantly associated with average daily gain or treatment for bovine respiratory disease. Yet, for every 1 g/L increase in serum Hp in the first week of life, the odds of being treated for any other disease during the study period increased by 7.6 times. Treatment for bovine respiratory disease, diarrhea, or any other disease resulted in increased odds of calf mortality. In addition, Hp concentration in the first week of life was associated with mortality in calves <4 mo of age. The optimal cut point for Hp was determined to be 0.13 g/L for the prediction of disease and death, although the sensitivity of Hp concentration alone as a diagnostic test for individual calves was low.