Using the Herd Status Index to remotely assess the welfare status of dairy herds based on prerecorded data.

The use of prerecorded data to remotely assess the herd welfare status is a promising approach to reduce the need for costly and time-consuming on-farm welfare assessments. Therefore, the objective of this study was to validate the Herd Status Index, an index developed based on Dairy Herd Improvement data from Canada, to remotely evaluate the welfare status of dairy herds. Herd-level prevalence of five animal-based welfare outcomes, measured once on 2 986 Quebec - Canada dairy herds between 2016 and 2019, were used to generate clusters with different welfare status using the algorithm partitioning around medoids. Dairy Herd Improvement data from 12 months prior to the welfare assessment were extracted and used to calculate the Herd Status Index. A linear model was used to carry out comparisons between clusters. Three stable clusters were found to best describe the data. Cluster two had the best overall welfare status since it had the lowest prevalence of all welfare issues while cluster three had the highest prevalence of most welfare issues, with the exception for the prevalence of neck lesions that was not different than cluster one. Cluster one had an overall intermediate welfare status. The Herd Status Index was higher (i.e., indicating a good welfare status) on cluster two compared to cluster three, but neither cluster three nor two differed to cluster one. In its current format, the Herd Status Index has a weak potential to identify herds with varying prevalence of welfare issues and it requires further improvements before it could be used to accurately assess the welfare status of the herds.

Keeping profitable cows in the herd: A lifetime cost-benefit assessment to support culling decisions.

Increasing the productive lifespan of dairy cows is important to achieve a sustainable dairy industry, but making strategic culling decisions based on cow profitability is challenging for farmers. The objective of this study was to carry out a lifetime cost-benefit analysis based on production and health records and to explore different culling decisions among farmers. The cost-benefit analysis was conducted for 22 747 dairy cows across 114 herds in Quebec, Canada for which feed costs and the occurrence of diseases were reported. Costs and revenues related to productive lifespan were compared among cohorts of cows that left their respective herd at the end of their last completed lactation or stayed for a complete additional lactation. Hierarchical clustering analysis was carried out based on costs and revenues to explore different culling decisions among farmers. Our results showed that the knowledge of lifetime cumulative costs and revenues was of great importance to identify low-profitable cows at an earlier lactation, while only focusing on current lactation costs and revenues can lead to an erroneous assessment of profitability. While culling decisions were mostly based on current lactation costs and revenues and disregarded the occurrence of costly events on previous lactations, there was variation among farmers as we identified three different culling decision clusters. Monitoring cumulative costs and revenues would help farmers to identify low-profitable cows at an earlier lactation and make the decision to increase herd productive lifespan and farm profitability by keeping the most profitable cows.

Graduate Student Literature Review: What is known about the eliminative behaviors of dairy cattle?

The eliminative behaviors of dairy cattle include frequencies and distribution over time and space for defecations and urinations, how the animal responds to cow-related and environmental factors by way of altered patterns of defecation and urination, and how an animal carries out and responds to its own acts of elimination. This review discusses the available literature to first define and describe eliminative behaviors of dairy cattle; what follows is a discussion on what can affect eliminative behaviors and methods for managing them. Information regarding these behaviors is sparse for dairy cattle and is largely centered around frequencies and distributions over the day. Relationships exist between eliminative behaviors and activity levels of the animals and activity levels of the people who manage them, suggesting that types of housing systems play a key role in mainly where and when eliminations occur. It also seems that individual animals vary in their elimination frequencies, in which case it may be interesting to determine what aspects of their individuality contribute to these differences. Although aspects of housing are intended to separate animals from their excreta, stalls or cubicles are not necessarily designed with cattle's natural eliminative behaviors in mind. Refining the timing of management routines and training of animals are some options in the next steps toward managing eliminative behaviors.

A survey of dairy goat kid-rearing practices on Canadian farms and their associations with self-reported farm performance.

Although future production of dairy goats is influenced by kid-rearing practices, little is known regarding which practices maximize kid growth, welfare, and future production success. The objectives of this survey study were to (1) identify common rearing practices of Canadian commercial dairy goat farms and evaluate their associations with 6 farm performance indicators and (2) determine if farms could be grouped by management style on the basis of the 6 performance indicators and compare rearing practices common across the different groups. A survey was sent by post or electronic media to reach dairy goat producers across Canada. The questionnaire contained 70 questions on the following areas of kid rearing: kidding management, care of newborn, colostrum management, milk and solid feeding in the preweaning period, health management, disbudding, housing conditions, weaning strategies, record keeping and growth monitoring, and farm performance data. Performance indicators, calculated on self-reported data, were 305-d milk production, preweaning mortality rate, diarrhea and respiratory disease prevalence, average daily gain from birth to weaning, herd milk production, and replacement rate. A total of 175 questionnaires were returned. After applying inclusion criteria, including herd size (≥40 goats) and completeness of surveys, 104 respondents from Ontario (n = 72, 69%), Québec (n = 23, 22%), and the Western provinces (n = 9, 9%) were retained for analysis, representing 29% of all Canadian producers. Farm sizes ranged from 42 to 2,500 (median = 190) goats. A large amount of variation in rearing practices and farm performance was found between farms. Colostrum and milk feeding management were found to be associated with all performance indicators except for kid respiratory disease prevalence, with timing of colostrum delivery and feeding method accounting for most the associations within each of the 2 areas. Replacement rate was mostly affected by whether or not kids were reared with their dam. Herds surveyed in the study could successfully be divided into 3 distinct groups (production-focused, longevity-focused, and low performance), representing different management styles on the basis of farm self-reported performance levels. Rearing practices found to be associated with higher farm performance could be targeted by advisory services to help improve management practices on Canadian dairy goat farms.

The hidden cost of disease: II. Impact of the first incidence of lameness on production and economic indicators of primiparous dairy cows.

Lameness is a persistent and underreported health and welfare problem in the dairy industry, resulting in reduced cow performance and profitability as well as early culling. The study objectives were (1) to quantify the impact of the first instance of lameness, at different stages of lactation, on production and economic performance, and (2) to further quantify the impacts of the first instance of lameness when only cows that remain in the herd for at least 100 d in milk (DIM) and those that remain for 305 DIM are included in the analysis. A retrospective longitudinal study was conducted using pre-existing data from animal health records and Dairy Herd Improvement Association records. Data were edited based on selected inclusion criteria, yielding a data set containing records from 15,159 first-lactation Holstein cows from 120 herds with year of first calving between 2003 and 2014. Lame cows were assigned to 1 of 4 groups based on when in the lactation the first event of lameness occurred: transition (1-21 DIM), early lactation (22-100 DIM), mid-lactation (101-200 DIM), or late lactation (201+ DIM). Mid- and late-lactation lame cows were also stratified by cumulative milk yield before the lameness event. Healthy cows (i.e., no recorded lameness event) were randomly assigned for each lactation stage, with mid-lactation healthy and late-lactation healthy cows similarly stratified. Production performance (cumulative milk, fat, and protein yield) and economic performance [milk value, margin over feed cost (MOFC), and gross profit] were analyzed using a mixed model with herd as a random effect. Cumulative milk yields were 811 to 1,290 kg lower for lame cows than for healthy cows, with milk component yields undergoing similar reductions. Reductions in milk yield contributed to losses in milk value (-Can$527 to -Can$1,083; -US$419 to -US$862) and MOFC (-Can$510 to -Can$774; -US$406 to -US$616). Higher losses were reported using gross profit (-Can$753 to -Can$1,052; -US$599 to -US$837), which includes all lameness-related costs. Production and performance losses were smaller when 100 DIM and 305 DIM thresholds were applied (i.e., exclusion of cows culled before 100 and 305 DIM, respectively), however, mid- and late-lactation lame cows maintained high levels of significant losses for all 6 variables analyzed. Lameness also led to higher levels of culling, masking losses for transition and early-lactation lame cows in the 305-DIM analysis. Increasing producer understanding of the costs associated with lameness not only serves to provide insight to producers for more informed culling decisions, but may also help producers weigh the costs of adopting new methods and technologies targeted at reducing on-farm lameness.

The hidden cost of disease: I. Impact of the first incidence of mastitis on production and economic indicators of primiparous dairy cows.

Mastitis is a highly prevalent disease, which negatively affects cow performance, profitability, welfare, and longevity. The objectives of this study were (1) to quantify the impact of the first instance of mastitis, at different stages of lactation, on production and economic performance, and (2) to further quantify the impact of the first instance of mastitis when only cows that remain in the herd for at least 100 d in milk (DIM) and those that remain for 305 DIM are included in the analysis. A retrospective longitudinal study was conducted using data from existing animal health record files and Dairy Herd Improvement records. After editing based on selected inclusion criteria and completeness of health records, data consisted of records from first-lactation Holstein cows, from 120 herds, that calved for the first time between 2003 and 2014, inclusive. Mastitic cows were assigned to 1 of 4 groups based on when in the lactation the first event of mastitis occurred: transition (1-21 DIM), early lactation (22-100 DIM), mid lactation (101-200 DIM), or late lactation (201+ DIM). Mid-lactation and late-lactation mastitic cows were also stratified by cumulative milk yield before the mastitis event. Healthy cows (i.e., no recorded mastitis event) were randomly assigned for each lactation stage, with mid-lactation healthy and late-lactation healthy cows similarly stratified. Production performance (cumulative milk, fat, and protein yield) and economic performance [milk value, margin over feed cost (MOFC), and gross profit] were analyzed using a mixed model with herd as a random effect. Significant losses in cumulative milk yield (-382 to -989 kg) and correspondingly lower fat and protein yields were found in mastitic cows, with transition and late-lactation mastitic cows having the highest losses. Drops in production translated to significant reductions in cumulative milk value (-Can$287 to -Can$591; -US$228 to -US$470), MOFC (-Can$243 to -Can$540; -US$193 to -US$429), and gross profit (-Can$649 to -Can$908; -US$516 to -US$722) for mastitic cows at all stages. Differences between mastitic and healthy cows in the early lactation and transition stages remained for all variables in the 100-DIM analysis, but, aside from gross profit, were nonsignificant in the 305-DIM analysis. Gross profit accounted for all costs associated with mastitis and thus continued to be lower for mastitic cows at all stages, even in the 305-DIM analysis in which culled cows were omitted (-Can$485 to -Can$979; -US$386 to -US$779). The research reflects the performance implications of mastitis, providing more information upon which the producer can make informed culling decisions and maximize both herd profitability and cow longevity.

Graduate Student Literature Review: The effect of housing systems on movement opportunity of dairy cows and the implications on cow health and comfort.

Intensification within the dairy industry has led to an increase in use of more restrictive indoor housing systems (most commonly tiestalls and freestalls) and less use of the pasture-based housing systems used in past generations. These indoor housing systems are associated with not only a higher level of restriction to cow movement, but also with a higher prevalence of lameness and cow comfort issues on farm, which negatively affects cow welfare, public perceptions, and producer profitability. In looking for solutions to these issues, several studies have investigated different housing and management options that are less restrictive and increase cow movement opportunity. We hypothesized that movement opportunity, briefly summarized as the level of locomotor activity a cow is able to express in her given environment as well as the ease with which said movement can be expressed, can have a direct, substantial effect on cow comfort as well as cow leg and hoof health. Lying behaviors, which serve as common indicators of cow comfort, are affected not only by the ease of movement that comes with providing more movement opportunity within the lying environment, but also by the aforementioned improvements to leg health. This is particularly true regarding the ability to display different lying postures and to rise and lie down with ease. The complexity of the relationship between the different methods by which movement opportunity can be provided to dairy cows and the corresponding effects on outcome measures related to cow health and comfort is an area of research that warrants exploration. In this literature review, we sought to identify how level of movement opportunity, provided though different housing systems and management practices, affects cow hoof and leg, udder, and reproductive health, as well as the effects that it has on cow lying behaviors that are indicative of comfort.

Graduate Student Literature Review: Current recommendations and scientific knowledge on dairy goat kid rearing practices in intensive production systems in Canada, the United States, and France.

Dairy goat kid rearing is the foundation of future milk production, yet little is known on this topic. References available to producers are limited, making it more difficult for dairy goat farms to reach their full production potential. This review paper aimed to identify the current recommendations on dairy goat kid rearing practices for intensive production systems and to assess whether the different recommendations were based on scientific literature. Recommendations on dairy goat kid rearing practices, from birth to weaning inclusively, were presented and compared between countries under similar intensive production systems, including Canada, the United States, and France. The different areas of rearing investigated included kidding management, colostrum management, liquid and solid feeding, health management, disbudding, housing, weaning, and growth monitoring. Gaps in the literature were identified in all areas except for disbudding. More research on the topic of goat kid raising practices would be beneficial to refine and validate current recommendations.

Graduate Student Literature Review: The effect of chain length and stall width on common outcome measures of dairy cow welfare in stall-based housing systems.

Given increased societal concern for the welfare of dairy cattle and the heightened concern of consumers about the ability of cows to fulfill their needs for rest and for movement, an understanding of the effect of stall-based housing systems on such needs becomes of prime scientific importance. In tie-stall systems, the ability of the cow to express her need for movement is largely affected by tethering; increasing chain length increased the cow's ease of movement in the space allowed to her. Regarding the ability of the cow to rest, the size of the stall bed (including its width) has been linked with measures of lying time. For the most part, current industry recommendations are not being followed on commercial farms, although improvements in terms of compliance seem to have been made in the last decade. Following the recommendations for chain length appears to aid in reducing the prevalence of injuries and may even aid in maintaining the cleanliness of the cows, although the few studies available are inconsistent. Wider stalls were associated with increased lying time and reduced prevalence of injuries, although in the latter case, data from different studies show inconsistent results. The link between stall width and common welfare outcome measures appears more clearly in tiestall systems, although improving the lateral space allowance for cows reduces collisions with equipment in freestall systems as well. Overall, the width of the stall and the length of the chain play roles in modulating the cows' ability to rest and to move comfortably in the confines of the stall, and should be carefully considered when designing stall-based housing systems that enhance the welfare of dairy cows.

Making tiestalls more comfortable: I. Adjusting tie-rail height and forward position to improve dairy cows' ability to rise and lie down.

The overall goal of the study was to develop new recommendations for tie-rail placement combining both vertical and horizontal positions to improve dairy cow welfare. Four treatments were tested: 2 new tie-rail positions that followed the natural neckline of cows when feeding and rising [neckline 1 (NL1), neckline 2 (NL2)], current recommendation (CR), and the average tie-rail position currently found on Quebec farms (current average on farm; CF). All other stall dimensions followed CR based on average cow size. Forty-eight cows blocked by parity and stage of lactation were randomly allocated to a treatment for 10 wk. Live scoring was performed weekly to evaluate injury, cow and stall cleanliness, and bedding quantity. Daily lying time, lying bout frequency, and lying bout duration were continuously recorded using leg-mounted accelerometers. Cows were recorded 1 d/wk by overhead cameras to evaluate lying down and rising events. Tie-rail placement did not affect cow and stall cleanliness, bedding quantity, and lying time. All tie-rail placements tested resulted in neck injuries with the position of neck injuries shifting based on the change in tie-rail placement: CR increased in proximal neck injuries (mean ± standard deviation, difference in injury score from baseline: +0.89 ± 0.153) compared with NL2 (+0.06 ± 0.153), but decreased in medial neck injuries (-0.11 ± 0.166) compared with NL2 (+0.78 ± 0.166) and NL1 (+0.53 ± 0.166). All treatments showed a decrease over time in average lying intention time (mean, difference between overall short- and long-term: -5.8 s/event), lying-down time (-1.1 s/event), contact with stall during lying (-32.5%), slipping during lying (-9.1%), backward movement on knees during rising (-10.9%), contact with tie-rail during rising (-14.3%), and overall abnormal rising (-15.6%) over time. Although lying and rising ability improved over time, abnormal lying and rising behaviors were still highly prevalent in the long term. Overall, our results show that dairy cows are limited in their ability to move within their environment without coming in contact with the stall confines (tie-rail and divider bars), warranting further research to determine alternatives to metal tie-rail bars, such as a flexible bar or chain, or provide fewer obstacles through the elimination of some stall hardware.

Making tiestalls more comfortable: IV. Increasing stall bed length and decreasing manger wall height to heal injuries and increase lying time in dairy cows housed in deep-bedded tiestalls.

Poor stall configuration can negatively affect cow welfare by impairing lying behavior and leading to injuries in dairy cows. The comfort of the stall bed in tiestalls is affected by the material components of the stall bed (stall base and bedding), but also by the amount of space provided. The amount of space cows are able to access lengthwise in a tiestall is determined by the stall bed length and the height of the manger wall (the front limit of the stall bed), which can limit access into the space available at the front of the stall. This project aimed to maximize cow comfort in deep-bedded tiestalls by investigating the combined effect of increased bed length and decreased manger wall height in a crossover experiment (2 periods with 1 wk habituation + 6 wk data collection). Two rows of 12 tiestalls were modified (n = 24 cows). Each row was a different length, short (178 cm; length commonly found in Quebec) or long (188 cm), and cows remained on the same row (same stall bed length) for the entire experiment. In each row, there were 6 stalls of each manger wall height treatment: high (20 cm, upper limit recommended) or low (5 cm). During period 2, cows switched manger wall height treatments. A 7.6-cm-deep straw bedding layer was added to all stalls by adding a bedding keeper to the ends of stalls. All initially injured locations healed over the 14-wk study, and 2 patterns of healing emerged. Improvement in hock injury (lateral tarsal and calcanei) was observed from wk 1 to 6 for all treatments. A plateau in injury severity score reduction was observed in period 2 for the hock (lateral, dorsal, and medial calcanei), anatomical knee, carpal joints (front knees), and proximal and medial neck, which was likely the result of the insensitivity of the injury scoring scheme rather than healing not occurring. Cows in long stalls were found to spend more time lying (14.1 vs. 13.3 h/d) and had longer lying bouts than cows in short stalls (74.1 vs. 52.9 min/bout). Manger wall height did not affect injury or lying time, but may affect how cows position themselves while lying. Higher lying times in our study were comparable to those reported in deep-bedded loose pens, indicating that cows with more bedding, especially those in long stalls, were more comfortable. Our results suggest that deep-bedded straw stalls with bedding keepers have the potential to be beneficial to cow comfort on tiestall farms.

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.

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.

The effect of housing tiestall dairy cows in deep-bedded pens during an 8-week dry period on gait and step activity.

Increasing locomotor activity can improve leg health and decrease the prevalence of lameness in dairy cows. The dry period offers an opportunity to provide alternative housing to tiestall (TSL) cows that can increase locomotor activity. The objective was to determine whether housing TSL dairy cows in a deep-bedded loose pen (LP) during the 8-wk dry period affected gait and step activity. Twenty cows, paired by parity and calving date, were assigned at dry-off to a deep-bedded LP or a TSL. Step activity was measured by leg-mounted pedometers. Cows were walked 1×/wk on a test corridor, and video recordings of gait were taken. Six aspects of gait were scored on a 0-to-5 scale (interval: 0.1 unit): tracking up, joint flexion, back arch, asymmetric step, swing, and reluctance to bear weight. Overall gait was also scored using a 1-to-5 scale (interval: 0.5 unit). Data for gait were analyzed based on the change in gait between dry-off and calving. Daily step data were averaged per week of the dry period. Analyses were performed using a mixed model with treatment, term, and block as fixed effects and cow nested within treatment and block as a random effect for step data. The same model, omitting the fixed effect of week, was used for gait variable analyses. There was no difference in step activity between LP and TSL cows (842.1 ± 88.86 vs. 799.5 ± 76.92 steps/d, LP vs. TSL, respectively). Only joint flexion yielded a treatment difference, with LP cows improving over time and TSL cows worsening (-0.4 ± 0.15 vs. 0.2 ± 0.15). Possibly owing to individual variation in motivation to perform locomotor activity, higher levels of step activity, independent of treatment, tended to be correlated with improvements in swinging out, tracking up, joint flexion, and overall gait score. The increased space allotted to LP cows may have allowed for a larger range of motion for each step, and the denser lying surface may have provided a cushioning effect when transitioning between rising and lying, all of which can improve joint health, reflected in improved joint flexion. Further investigation is warranted into the potential benefits of alternative housing on cow comfort, movement opportunity, and cow condition.

Performance perception of Canadian dairy producers when transitioning to an automatic milking system.

Adoption of automated milking systems (AMS) has increased exponentially around the world in recent years. The objective of this observational study was to evaluate how producer perception of changes in cow-average milk yield and somatic cell count (SCC) compared with the actual changes in their herds after the introduction of AMS in Canadian commercial dairy herds. Data were collected (in 2014 and 2015) through a survey of 97 Canadian dairy herds that shifted to AMS from 2000 to 2014. Producers were asked their perception about milk yield and SCC changes (increase, decrease, or no change) after AMS introduction. Actual herd performance data were obtained from dairy herd improvement organizations. Differences between the 12-mo rolling herd-average milk yield (kg/cow per year) and SCC (cells/mL) at the closest test 2 yr after transitioning to AMS and at the last test before the transition were calculated and compared with the producer perception answers. After AMS adoption, milking herd size, milk yield, SCC, and number of AMS units per herd averaged (± standard deviation) 99.8 ± 54.4 cows, 9,619 ± 1,354 kg/cow per year, 248,825 ± 97,286 cells/mL, and 1.9 ± 1.1 units, respectively. On average, after AMS introduction, herd size, milk yield, and culling rate increased by 11.3 cows, 441 kg/cow per year, and 1.3%, respectively, and calving interval decreased by 7 d. For producers who perceived an increase, actual milk yield and SCC increases averaged (mean ± standard deviation) +534 ± 1,003 kg/cow per year and +56,679 ± 66,662 cells/mL, respectively. Alternatively, for producers who perceived a decrease, actual milk yield and SCC decreases averaged -984 ± 658 kg/cow per year and -26,976 ± 94,099 cells/mL, respectively. An actual milk yield change of +83.1 ± 1,113.3 kg/cow per year and an SCC change of +6,135 ± 72,609 cells/mL were observed in the herds in which the dairy producers perceived no change with the AMS introduction. Hence, dairy producers were, on average, able to discern their actual milk yield and SCC changes after AMS adoption. However, the proportions of dairy producers who accurately perceived their actual milk yield and SCC changes after AMS introduction were 39.4% for milk yield (increase: 36.3%; decrease: 100.0%; and no change: 45.5%) and 46.7% for SCC (increase: 50.0%; decrease: 39.0%; and no change: 54.1%). From these results, we concluded that several dairy producers distorted their actual milk yield and SCC changes or were not fully aware of those changes.

Graduate Student Literature Review: The effects of bedding, stall length, and manger wall height on common outcome measures of dairy cow welfare in stall-based housing systems.

Understanding and improving dairy cow welfare in stall-based housing systems is an important issue for the dairy industry, and one area of the stall that has a large impact on cow welfare is the stall bed. The stall bed is defined both by its size and by the material components of the stall bed (bedding depth, bedding type, and stall base type). This review examines the current literature to determine how the material components of the stall bed, as well as bed length and manger wall/brisket board height (which together define the length of the stall bed) can affect cow welfare through lying time, injuries, lameness, and cow and stall cleanliness. Of the material components of the stall bed, bedding depth appears to have the largest potential positive impact on dairy cow welfare, as deeper levels of bedding in stalls, regardless of the bedding type, can improve compressibility to the extent that the stall base type is negligible. As such, deeper levels of bedding have been associated with increased lying time and a reduced likelihood of a cow developing injuries or becoming lame. Longer stall bed lengths have been shown to increase lying time and decrease the prevalence of injury and lameness. The effect of manger wall or brisket board height on cow welfare has not been studied extensively, but they may work in conjunction with other stall components to define the resting space available to the cow. Overall, the material components of the stall bed, stall length, and manger wall/brisket board height, as well as their combination, all influence cow welfare and need to be taken in consideration to improve the overall welfare of cows in stall-based housing systems.

Housing tiestall dairy cows in deep-bedded pens during an 8-week dry period: Effects on lying time, lying postures, and rising and lying-down behaviors.

Dairy cow lying behavior is useful in determining the cow's level of welfare, as well as in determining how her environment may affect her comfort and ease of movement. In tiestall systems, cows usually remain in a stall for the duration of their lactation. The dry period offers a unique opportunity to provide alternative housing to the cow with minimal effects on farm housing and management. Our objective was to determine whether housing tiestall cows in deep-bedded pens over an 8-wk dry period altered lying time, lying and rising ability, or lying postures. At dry-off, 20 cows, paired by parity and calving date, were randomly assigned to a deep-bedded loose pen (LP) or a tiestall (TS). Leg-mounted pedometers measured lying time. Rising and lying ability were measured using 6 events of rising and lying from 24-h video recordings taken once a week per cow. Sequenced images (1/min) from the 24-h recordings were used to document lying postures and locations for each cow. Data were analyzed for the early (first week of dry-off), mid, and late (week before calving) terms of the dry period. Lying time did not differ between LP and TS but was numerically higher for LP than TS cows (14.4 vs. 13.0 h/d, respectively). Contact with stall or pen confines when lying down was 5 times higher in TS than LP. The increased contact, coupled with a higher occurrence of hindquarter shifting in the late term, led to higher overall abnormal lying behaviors in TS. Contact with the stall upon rising increased in the late term for TS cows. Cows housed in loose pens also exhibited greater variation in hind-leg postures, keeping legs tucked 20% less often in favor of alternative postures. Stall hardware (e.g., tie rail, dividers) may have affected the ease of transition between lying and standing, leading to higher levels of contact with the stall. Loose-pen cows are able to assume more postures than TS cows when provided more space, possibly allowing them to orient themselves in ways that provide greater comfort. Lying surface in the deep-bedded loose pen may ease the cow's lying-down and rising movements and lead to the higher lying time found with LP cows. Overall, aspects of the stall largely contributed to differences in lying behaviors, warranting further study into whether freestall systems would yield similar outcomes. Improving our concept of ease of movement related to lying and quality of rest in dairy cows, through evaluating lying behaviors in different housing systems, allows for better recommendations on viable alternative housing options.

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.

Technical note: Validation of an ear-tag accelerometer to identify feeding and activity behaviors of tiestall-housed dairy cattle.

The objective of this study was to validate the CowManager SensOor ear-tag accelerometer (Agis Automatisering BV, Harmelen, the Netherlands) against visual observations of feeding, rumination, resting, and active behaviors of tiestall-housed dairy cows. Prior validation of the sensor has been published for freestall and grazing dairy herds. However, the behavioral differences that exist among these and a tiestall system necessitate additional validation. Lactating Holstein cows (n = 10) at different lactation stages and parities were included in the study. Cows were monitored both visually and with the sensor for 10 h/d for 4 consecutive days (10 cows × 10 h × 4 d = 400 h of observation total). A single trained observer classified each minute of visual observation into 1 of 13 behaviors and then summarized them into the 4 behavioral categories of eating, rumination, not active, or active. The sensor registered ear movements continuously and, based on a proprietary model, converted them into the behavioral categories. Multivariate mixed models were run to obtain covariance estimates, from which correlation coefficients were computed to assess agreement between visual observation and sensor data. The models included the percentage of time spent performing each behavior per day as the dependent variable and technology (visual observation versus sensor) and day as fixed effects. The models also included the random effects of technology and the repeated effects of technology and day. The correlation strength between visual observation and sensor data varied from poor to almost perfect by behavioral category (eating: r = 0.27; rumination: r = 0.69; eating-rumination: r = 0.83; not active: r = 0.95; and active: r = 0.89). The results suggest that the sensor can be used to accurately monitor active and not-active behaviors of tiestall-housed dairy cows. The results also suggest that although the sensor shows promise for identifying feeding behaviors in general, the independent classification of rumination and eating requires additional sensitivity.

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.