Farm-level risk factors associated with increased milk ß-hydroxybutyrate and hyperketolactia prevalence on farms with automated milking systems.

The objectives of this study were to determine the farm-level hyperketolactia (HKL) prevalence, as diagnosed from milk ß-hydroxybutyrate (BHB) concentration, on dairy farms milking with an automatic milking system (AMS) and to describe the farm-level housing, management, and nutritional risk factors associated with increased farm-average milk BHB and the within-herd HKL prevalence in the first 45 DIM. Canadian AMS farms (n = 162; eastern Canada n = 8, Quebec n = 23, Ontario n = 75, western Canada n = 55) were visited once between April to September 2019 to record housing and herd management practices. The first test milk data for each cow under 45 DIM were collected, along with the final test of the previous lactations for all multiparous cows, from April 1, 2019 to September 30, 2020. The first test milk BHB was then used to classify each individual cow as having HKL (milk BHB ≥ 0.15 mmol/L) at the time of testing. Milk fat and protein content, milk BHB, and HKL prevalence were summarized by farm and lactation group (all, primiparous, and multiparous). During this same time period, formulated diets for dry and lactating cows, including ingredients and nutrient composition, and AMS milking data were collected. Data from the AMS were used to determine milking behaviors and milk production of each herd during the first 45 DIM. Multivariable regression models were used to associate herd-level housing, feeding management practices, and formulated nutrient composition with first test milk BHB concentrations and within-herd HKL levels separately for primiparous and multiparous cows. The within-herd HKL prevalence for all cows was 21.8%, with primiparous cows having a lower mean prevalence (12.2 ± 9.2%) than multiparous cows (26.6 ± 11.3%). Milk BHB concentration (0.095 ± 0.018 mmol/L) and HKL prevalence for primiparous cows were positively associated with formulated prepartum DMI and forage content of the dry cow diet while being negatively associated with formulated postpartum DMI, the major ingredient in the concentrate supplemented through the AMS, and the PMR-to-AMS concentrate ratio. However, multiparous cows' milk BHB concentration (0.12 ± 0.023 mmol/L) and HKL prevalence were positively associated with the length of the previous lactation, milk BHB at dry off, prepartum diet nonfiber carbohydrate content, and the major forage fed on farm, while tending to be negatively associated with feed bunk space during lactation. This is the first study to determine the farm-level risk factors associated with herd-level prevalence of HKL in AMS dairy herds, thus helping optimize management and guide diet formulation to promote the reduction of HKL prevalence.

Farm-level nutritional factors associated with milk production and milking behavior on Canadian farms with automated milking systems.

The objective of this study was to describe nutritional strategies utilized on Canadian dairy farms with automated milking systems (AMS), both at the feed bunk and the concentrate offered at the AMS, as well as to determine what dietary components and nutrients, as formulated, were associated with milk production and milking behaviors on those farms. Formulated diets, including ingredients and nutrient content, and AMS data were collected from April 1, 2019, until September 30, 2020, on 160 AMS farms (Eastern Canada [East] = 8, Ontario [ON] = 76, Quebec [QC] = 22, and Western Canada [West] = 54). Both partial mixed ration (PMR) and AMS concentrate samples were collected from May 1 to September 30, 2019, on 169 farms (East = 12, ON = 63, QC = 42, West = 52). AMS milking data were collected for 154 herds. For each farm (n = 160), milk recording data were collected and summarized by farm to calculate average milk yield and components. Multivariable regression models were used to associate herd-level formulated nutrient composition and feeding management practices with milk production and milking behavior. Milk yield (37.0 ± 0.3 kg/d) was positively associated with the PMR ether extract (EE) concentration (PMR % EE; +0.97 kg/d per percentage point (p.p.) increase) and with farms that fed barley silage as their major forage source on farm (n = 16; +2.18 kg/d) compared with haylage (n = 42), while farms that fed corn silage (n = 96; +1.23 kg/d) tended to produce more milk than farms that fed haylage. Greater milk fat content (4.09 ± 0.28%) was associated with greater PMR-to-AMS concentrate ratio (+0.02 p.p. per unit increase) and total diet net energy for lactation (+0.046 p.p. per 0.1 Mcal/kg increase), but lesser % non-fiber carbohydrates (NFC) of the PMR (-0.016 p.p. per p.p. increase of % NFC). Milk protein content (3.38 ± 0.14%) was positively associated with forage % of the PMR (+0.003 p.p. per p.p. increase of % forage) and total diet % starch (+0.009 p.p. per p.p. increase of % starch), but negatively associated with farms feeding corn silage (-0.1 p.p. compared with haylage) as their major forage. Greater milking frequency (2.77 ± 0.40 milkings/d) was observed on farms with free-flow cow traffic systems (+0.62 milkings/d) and positively associated with feed push-up frequency (+0.013 milkings/d per additional feed push-up), while being negatively associated with PMR NFC content and % forage of the total ration (-0.017 milkings/d per p.p. increase of % forage). Lastly, greater milking refusal frequency (1.49 ± 0.82 refusals/d) was observed on farms with free-flow cow traffic systems (+0.84 refusals/d) and farms feeding barley silage (+0.58 refusals/d) than guided flow and farms feeding either corn silage or haylage, respectively. These data give insight into the ingredients, nutrient formulations and type of diets fed on AMS dairy farms across Canada and the association of those factors with milk production and milking behaviors.

Characterizing the diagnostic sensitivity and specificity of pain biomarkers in cattle using receiver operating characteristic curves.

Biomarkers are used to assess pain and analgesic drug efficacy in livestock. However, often the diagnostic sensitivity and specificity of these biomarkers for different painful conditions over time have not been described. Receiver operating characteristic (ROC) curves are graphical plots that illustrate the diagnostic ability of a test as its discrimination threshold is varied. The objective of this analysis was to use area under the curve (AUC) values derived from ROC analysis to characterize the predictive value of potential pain biomarkers at specific time points following a painful stimulus. The biomarkers included in the analysis were plasma cortisol, salivary cortisol, hair cortisol, infrared thermography (IRT), mechanical nociceptive threshold (MNT), substance P, kinematic gait analysis, and a visual analog scale for pain. A total of 7,992 biomarker outcomes collected from 7 pain studies involving pain associated with castration, dehorning, lameness, and abdominal surgery were included in the analysis. Each study consisted of 3 treatments: uncontrolled pain (tissue damage), no pain (handled controls), and analgesic use (tissue damage, administered a nonsteroidal anti-inflammatory drug). Results comparing analgesic effects to uncontrolled pain consistently yielded AUC values >0.7 (95% confidence interval: 0.40 to 0.99) for plasma cortisol (time points: 1.5, 2, 3, 4, 6, and 8 h), hair cortisol (time point: 62 d), and IRT (time point: 72 h). Results comparing analgesic effects to uncontrolled pain consistently yielded AUC values <0.7 (95% confidence interval: 0.28 to 0.90) for salivary cortisol (6, 13, 20, 34, 48, and 62 d); MNT (6, 25, and 49 h); substance P (1, 2, 3, 4, 6, 8, 12, 18, 24, 48, 72, 96, 120, 144, 312, 480, 816, 1,152, and 1,488 h); kinematic gait analysis including area (8, 16, 48, 72, 96, and 120 h), force (8, 16, 24, 48, 72, 96, and 120 h), and pressure (8, 16, 24, 48, 72, 96, and 120 h); and a visual analog scale for pain (1, 2, 3, 4, 5, and 6 d). These results indicate that ROC analysis can be used to characterize the predictive value of pain biomarkers and provide new knowledge on the diagnostic accuracy of pain biomarkers within this data set. This analysis, using data from 7 studies, was a preliminary approach to identify biomarkers and collection time points that could inform additional analytical approaches or meta-analyses with larger sample sizes, which are needed to further validate these hypotheses and conclusions.

Farm-level factors associated with lameness prevalence, productivity, and milk quality in farms with automated milking systems.

Impaired locomotion (lameness) may negatively affect the ability and desire of cows to milk voluntarily, which is a key factor in success of automated milking systems (AMS). The objective of this study was to identify factors associated with herd-level lameness prevalence and associations of lameness and other farm-level factors with milking activity, milk yield, and milk quality in herds with AMS. From April to September 2019, 75 herds with AMS in Ontario, Canada, were visited, and data on barn design and farm management practices were collected. Data from AMS were collected, along with milk recording data, for the 6-mo period before farm visits. Farms averaged 98 ± 71 lactating cows, 2.3 ± 1.5 robot units/farm, 43.6 ± 9.4 cows/robot, 36.4 ± 4.9 kg/d of milk, a milking frequency of 3.01 ± 0.33 milkings/d, and a herd average geometric mean SCC of 179.3 ± 74.6 (× 1,000) cells/mL. Thirty percent of cows/farm (minimum of 30 cows/farm) were scored for body condition (1 = underconditioned to 5 = over conditioned) and locomotion (1 = sound to 5 = lame; clinically lame ≥3 out of 5 = 28.3 ± 11.7%, and severely lame ≥4 out of 5 = 3.0 ± 3.2%). Clinical lameness (locomotion score ≥3) was less prevalent on farms with sand bedding, with increased feed bunk space per cow, and on farms with non-Holstein breeds versus Holsteins, and tended to be less prevalent with lesser proportion of underconditioned cows (with body condition score ≤2.5). Severe lameness occurrence (farms with any cows with locomotion score ≥4) was associated with a greater proportion of underconditioned cows and in farms with stalls with greater curb heights. Herd average milk yield/cow per day increased with lesser prevalence of clinical lameness (each 10-percentage-point decrease in clinical lameness prevalence was associated with 2.0 kg/cow per day greater milk yield) and greater milking visit frequency per day, and tended to be greater with increased feed push-up frequency. Lesser herd average somatic cell count was associated with lesser clinical lameness prevalence, herd average days in milk, and proportion of overconditioned cows, and somatic cell count tended to be lesser for farms with sand bedding versus those with organic bedding substrates. The results highlight the importance of minimizing lameness prevalence, using of sand bedding, ensuring adequate feed access and feed bunk space, and maintaining proper cow body condition to optimize herd-level productivity and milk quality in AMS herds.

Impact of volume, immunoglobulin G concentration, and feeding method of colostrum product on neonatal nursing behavior and transfer of passive immunity in beef calves.

One-third of beef calves fail to achieve adequate transfer of passive immunity (TPI) through timely ingestion of colostrum, which substantially increases their risk of preweaning morbidity and mortality. Two randomized clinical trials were designed to assess the impact of volume, immunoglobulin G (IgG) concentration, and feeding method of colostrum product on neonatal nursing behavior and TPI. In Trial 1, 47 calves were randomly assigned to receive one of three colostrum interventions by oro-esophageal tube feeder (OET): 1 L with 100 g/L IgG, 1.4 L with 70 g/L IgG, or 2 L with 100 g/L IgG. In Trial 2, 29 calves were randomly assigned to be fed 1 L of colostrum product with 100 g/L IgG by either nipple bottle (NB) or OET. Colostrum intervention (i.e. feeding of colostrum product) occurred within 60 minutes of birth. Cow-calf pairs were monitored by video surveillance in individual stalls for 24 h. Dam colostrum was collected at 10 minutes and calf serum was collected at 24-36 h after birth to assess IgG concentration. Differences among colostrum intervention groups on latency to stand and nurse were analyzed using Kaplan-Meier survival curves and Cox proportional hazard models. The impact of colostrum intervention group on TPI was assessed using multivariable linear regression modeling. In Trial 1, calves fed 1.4 L with 70 g/L IgG by OET nursed from their dams statistically significantly earlier compared to calves fed 1 L with 100 g/L IgG (P = 0.003) and calves fed 2 L with 100 g/L IgG (P = 0.008). Six of the 15 calves in the NB group in Trial 2 refused to consume part of the colostrum feeding offered by bottle and required follow-up tube feeding of the remaining volume. These calves were analyzed as a separate group (NB + OET). Calves fed 1 L by NB stood and nursed statistically significantly earlier than calves fed by OET (P = 0.005) or a combination of NB + OET (P = 0.003). Calf serum IgG concentrations were not statistically significantly different among colostrum intervention groups (P > 0.1). Overall, the colostrum interventions assessed in this study led to only one calf with failed TPI. While statistically significant differences in serum IgG concentrations were not detected in this study, subsequent nursing behavior did vary and was improved by feeding a moderate volume (1.4 L with 70 g/L IgG) of colostrum when using an OET, and by using the NB when feeding a smaller volume (1 L with 100 g/L IgG).

Benchmarking of farms with automated milking systems in Canada and associations with milk production and quality.

The objective of this study was to benchmark the herd-level housing and management strategies of automated milking system (AMS) farms across Canada and assess the associations of these herd-level housing factors and management practices with milk production and quality. Canadian AMS farms (n = 197; Western Canada: n = 50, Ontario: n = 77, Quebec: n = 59, Atlantic Canada: n = 11) were each visited once from April to September 2019, and details were collected related to barn design and herd management practices. Milk-recording data for the 6 mo before farm visits were collected. Farms averaged (± standard deviation) 110 ± 102 lactating cows, 2.4 ± 1.9 AMS units/farm, 47.5 ± 14.9 cows/AMS, 36.7 ± 5.0 kg/d of milk, 4.13 ± 0.34% fat, 3.40 ± 0.16% protein, and a herd-average somatic cell count of 186,400 ± 80,800 cells/mL. Farms mainly used freestall housing systems (92.5%), organic bedding substrates (73.6%), and free flow cow traffic systems (87.8%); farms predominantly milked Holsteins (90.4%). Multivariable regression models were used to associate herd-level housing factors and management practices with milk production and quality. At the herd level, feed push-up frequency (mean = 12.8 ± 8.3 times per day) and feed bunk space (mean = 64 ± 21.5 cm/cow) were positively associated with milk yield. Greater milk yield was associated with herds using inorganic (sand) versus organic bedding, milking Holsteins versus non-Holsteins, and using a form of mechanical ventilation versus natural ventilation alone. Milk fat and milk protein content were only associated with breed. Herds with lower somatic cell counts had more frequent alley cleaning (mean = 12.1 ± 7.5 times per day), wider lying alleys (mean = 304.5 ± 40.0 cm), and sand bedding. The results highlight the importance of using sand bedding, using mechanical ventilation, keeping feed pushed up, ensuring alleys are clean, and ensuring adequate space at the feed bunk for maintaining herd-level productivity and milk quality in farms with AMS.

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.

Producer experience with transitioning to automatic milking: Cow training, challenges, and effect on quality of life.

Despite the growing popularity of automatic milking systems (AMS), or milking robots, in Canada, little documentation is available on how Canadian dairy producers experience the transition to this milking technology. The objective of this national study was to document the experiences of Canadian dairy producers during the transition to, and use of, AMS. This paper reports on producers' experiences with cow training, challenges during the transition and their solutions, and effect of the AMS on quality of life. The AMS producers (n = 217) were surveyed from 8 Canadian provinces. Overall, producers experienced a positive transition to AMS. Producers perceived that AMS improved profitability, quality of their lives and their cows' lives, and had met expectations, despite experiencing some challenges during transition such as learning to use the technology and data, cow training, demanding first few days, and changing health management. Less than half of the AMS producers (42%) trained cows or heifers to use the AMS before the first milking with the robot. Producers who implemented training before first milking reported that it took an average of 1 wk to train a cow or heifer to use the AMS. Producers reported it took a median of 30 d for an entire herd to adapt to the AMS, whether or not cow training took place. On average, 2% of a herd was culled for not adapting, or not voluntarily milking, when otherwise physically and behaviorally normal. With AMS, producers suggested they gained more time flexibility, found work to be less stressful and physically demanding, found employee management easier, and had improved herd health and management. The vast majority (86%) of producers would recommend others to transition to AMS.

Impact of automatic milking systems on dairy cattle producers' reports of milking labour management, milk production and milk quality.

Automatic milking systems (AMS), or milking robots, are becoming widely accepted as a milking technology that reduces labour and increases milk yield. However, reported amount of labour saved, changes in milk yield, and milk quality when transitioning to AMS vary widely. The purpose of this study was to document the impact of adopting AMS on farms with regards to reported changes in milking labour management, milk production, milk quality, and participation in dairy herd improvement (DHI) programmes. A survey was conducted across Canada over the phone, online, and in-person. In total, 530 AMS farms were contacted between May 2014 and the end of June 2015. A total of 217 AMS producers participated in the General Survey (Part 1), resulting in a 41% response rate, and 69 of the respondents completed the more detailed follow-up questions (Part 2). On average, after adopting AMS, the number of employees (full- and part-time non-family labour combined) decreased from 2.5 to 2.0, whereas time devoted to milking-related activities decreased by 62% (from 5.2 to 2.0 h/day). Median milking frequency was 3.0 milkings/day and robots were occupied on average 77% of the day. Producers went to fetch cows a median of 2 times/day, with a median of 3 fetch cows or 4% of the herd per robot/day. Farms had a median of 2.5 failed or incomplete milkings/robot per day. Producers reported an increase in milk yield, but little effect on milk quality. Mean milk yield on AMS farms was 32.6 kg/cow day. Median bulk tank somatic cell count was 180 000 cells/ml. Median milk fat on AMS farms was 4.0% and median milk protein was 3.3%. At the time of the survey, 67% of producers were current participants of a DHI programme. Half of the producers who were not DHI participants had stopped participation after adopting AMS. Overall, this study characterized impacts of adopting AMS and may be a useful guide for making this transition.

Effect of a single dose of meloxicam prior to band or knife castration in 1-wk-old beef calves: I. Acute pain.

In Western Canada, approximately half of the calves produced are castrated before 1 wk of age. Therefore, it is important to identify effective analgesic drugs to mitigate pain associated with castration and consequently improve animal welfare. The aim of this study was to assess the efficacy of a single s.c. dose of meloxicam at mitigating pain associated with knife and band castration in 1-wk-old calves. Seventy-two Angus crossbred bull calves (47.3 ± 6.70 kg of body weight (BW), 1 wk old) were used in a 3 × 2 factorial design where main factors included castration method-sham (CT), band (BA) or knife (KN) castration- and medication-lactate ringer (NM) or 0.5 mg/kg BW of meloxicam (M). Measurements included different physiological and behavioral parameters. Samples were collected on day -1, immediately before castration (T0); and 60, 90, and 120 min and 1, 2, 3, and 7 d after castration except for visual analog scale (VAS) which was collected at the time of castration. The salivary cortisol concentrations were greater (P = 0.04) in KN and BA calves than CT calves 60 min after castration, while 90 min after castration BA had greater concentrations than CT calves. Substance P concentrations were greater (P = 0.04) in NM calves than M calves on d 3 and 7 after castration. The serum amyloid-A (SAA) concentrations were greater (P = 0.05) in KN calves than BA and CT calves on days 0, 2, and 3, while BA calves had greater SAA concentrations on day 7 than KN and CT calves. The visual analog scores were greater (P < 0.01) in KN calves than BA, and in BA compared to CT calves. The KN calves tail flicked more (P < 0.01) than BA and CT calves, and NM calves tail flicked more (P = 0.03) than M calves. No castration or medication effect (P > 0.10) was observed for stride length, walking, standing, lying ventral, eating, foot stamping, head turning, lying and standing percentage, performance, platelets, or body temperature. Overall, knife castrated calves exhibited a greater acute pain response than band castrated calves. Meloxicam was able to reduce substance P concentrations, white blood cell counts and number of tail flicks after castration, suggesting that the drug was able to mitigate acute pain to some extent. However, meloxicam did not have an effect on the other physiological and behavioral parameters assessed.

Behavior and productivity of cows milked in automated systems before diagnosis of health disorders in early lactation.

Associations of electronically recorded data were examined before diagnosis of health disorders in early-lactation cows in herds with automated milking systems (AMS). Rumination time, activity, and milk yield data were collected for 8 mo for 605 early-lactation cows in 9 commercial AMS herds. Using multivariable generalized linear regression models controlling for parity and days in milk, data were examined relative to the day of diagnosis for health disorders occurring in absence of, or at least 14 d before, another disorder: mastitis (n = 13), new cases of lameness (n = 45), subclinical ketosis (SCK; n = 113), and purulent vaginal discharge (n = 49). All cases of displaced abomasum (DA; n = 8) occurred in conjunction with other disorders. Deviations from baseline among affected cows were examined, as well as differences compared with a group of healthy cows and an average group of all cows, who were given mock diagnosis days using the mean days in milk at diagnosis for each disorder. On 6 to 14 d of the 2 wk before diagnosis, cows with DA or mastitis had lower milk yield, rumination time, milking frequency, activity, and milk temperature compared with healthy cows as well as deviations from their own baseline rumination time and milk data starting 4 to 12 d before diagnosis. Cows with DA had lower AMS supplement intake than healthy cows and deviations from their baseline activity and milk temperature starting 6 and 4 d before diagnosis, respectively. Cows with mastitis had greater milk conductivity than healthy cows and deviated from their baseline milking frequency and conductivity 8 and 12 d before diagnosis, respectively. Compared with healthy cows, those with SCK or new cases of lameness generally had lower milk yield, rumination time, milk temperature, supplement intake, and milking and refusal frequencies. Only the milk temperature of lame cows deviated from baseline. Thus, acute health disorders (i.e., DA and mastitis) were associated with deviations from those cows' baseline AMS data, whereas more chronic disorders (i.e., SCK and lameness) were associated with significant but subtle longer term changes in milk production and behavior. Because cows with health disorders deviated from a group of healthy cows before they deviated from their own baseline and from the average of all other cows, including a healthy reference group in health alerts could refine the ability of detection models to identify subtle deviations in early lactation.

Predictors and impacts of colostrum consumption by 4h after birth in newborn beef calves.

Newborn beef calf vigor is a vital survival characteristic that promotes timely colostrum consumption. Modified APGAR scores intended to identify compromised calves are not widely adopted due to impracticality, inconsistent associations with blood gas disturbances, and unclear recommendations for intervention. The objectives were to: (1) determine differences in at-birth blood parameters between calves that were successful in colostrum consumption by 4h (CC4) compared to those that failed; (2) develop a Beef Calf Vigor Assessment by determining calving characteristics and clinical examination parameters associated with CC4; and (3) evaluate impacts of failed CC4 on transfer of passive immunity and treatment risk. As a predictor for CC4, suckle reflex had the highest specificity (98%), whereas calving ease had the highest sensitivity (89%). Calves with a weak suckle reflex had 41.6 (95% CI: 7.4-787.5) times greater odds of failed CC4 compared to calves with a strong suckle reflex (P<0.0001). Calves with failed CC4 had lower serum IgG (P=0.01), had lower odds of acquiring optimal passive immunity (>24g/L serum IgG; OR=6.4, 95% CI: 1.2-34.4; P=0.02), and higher odds of being treated (OR=2.8, 95% CI: 1.1-7.4; P=0.03) than those that succeeded. Measuring suckle reflex in combination with calving ease was a quick and easy method to assess newborn beef calf vigor. The value of this Beef Calf Vigor Assessment was further emphasized by the negative impacts of failed CC4 on transfer of passive immunity and pre-weaning health.

Effect of band and knife castration of beef calves on welfare indicators of pain at three relevant industry ages: II. Chronic pain.

Three experiments were conducted to evaluate the effects of band and knife castration on behavioral and physiological indicators of chronic pain in beef calves at 3 different ages (36 calves/age group): 1 wk of age (Exp. 1, 4 ± 1.1 d of age, 43 ± 1.1 kg BW), 2 mo of age (Exp. 2, 63 ± 2.3 d of age, 92 ± 1.7 kg BW), and 4 mo of age (Exp. 3, 125 ± 4.6 d of age, 160 ± 3.4 kg BW). In each experiment calves were randomly assigned to either sham (CT), band (BA) or knife (KN) castration. Experiments 1, 2, and 3 ended when the testicles of banded calves had sloughed off (68, 49, and 42 d, respectively). Animal BW and rectal temperature were recorded weekly over the experimental period. Salivary cortisol, substance P, haptoglobin, scrotal area temperature using infrared thermography, visual evaluation of swelling (5-point scale), and gait stride length were collected on d -1 and immediately before castration and weekly thereafter until the end of the study. Hair samples were collected 1 d prior to and 28 d after castration and at the end of the study for cortisol concentration. Standing and lying behaviors were recorded over a 28-d period immediately after castration. No differences ( > 0.10) were observed in salivary cortisol, substance P, haptoglobin, or hair cortisol among castration methods for any of the 3 ages. No changes in behavior were observed in calves castrated at 1 wk or 2 mo of age. In 4 mo-old-calves, BA spent less time lying ( < 0.01) than CT and KN calves. Also, the average duration of lying time for BA calves was greater ( < 0.05) than for CT calves. Both, 1-wk- and 2-mo-old calves had inflammation in the scrotal area lasting 7 d after KN castration, whereas inflammation was observed for up to 14 d in 4-mo-old calves. Swelling in BA calves lasted for 21 to 28 d in the 2 younger groups of calves, whereas in 4-mo-old calves swelling was observed until d 35 postcastration. Knife- and band-castrated calves did not exhibit indicators of chronic pain or distress when the procedures were performed in calves younger than 2 mo of age. Therefore, pain mitigation should be used when castrating to improve animal welfare, especially when castrations are performed in calves older than 2 mo of age independent of the method of castration.

Effect of band and knife castration of beef calves on welfare indicators of pain at three relevant industry ages: I. Acute pain.

Three experiments evaluated the effect of band and knife castration on acute pain for the first 7 d after the procedure on 1-wk-, 2-mo-, and 4-mo-old calves. All calves were blocked by age and weight and randomly assigned to 1 of 3 treatments: sham castration (control, CT), band castration (BA), and knife castration (KN). Experiment 1 evaluated 1-wk-old Angus bull calves ( = 34; 43.0 ± 6.61 kg BW), Exp. 2 evaluated 2-mo-old Angus bull calves ( = 34; 91.5 ± 11.93 kg BW), and Exp. 3 evaluated 4-mo-old Angus bull calves ( = 35; 157.6 ± 22.52 kg BW). For all experiments, physiological and behavioral parameters were collected before (d -1 and immediately before castration [T0]) and after (60 and 120 min and on d 7) castration to assess acute pain. Physiological measures included complete blood cell count, cortisol, substance P, and scrotal temperature. Behavioral measures consisted of a visual analog scale, stride length, and time and frequency budgets for walking, standing, lying, tail flicking, foot stamping, and head turning. Performance parameters included initial and final BW and ADG. In Exp. 1, tail flicking was greater ( = 0.02) in KN calves compared to BA calves 2 to 4 h after castration, although no differences were seen between BA and KN compared to CT calves. In Exp. 2, a treatment × time interaction ( = 0.02) was observed for cortisol, where KN calves had greater cortisol concentrations 120 min after castration compared to BA and CT calves; KN calves also lay down and ate less ( < 0.01; = 0.02) and stood and walked more ( < 0.01; = 0.05) compared to BA and CT calves 2 to 4 h after castration. In Exp. 3, a treatment × time interaction ( < 0.01) was observed for cortisol concentrations in which all treatments were different from one another at 60 and 120 min, with BA calves having the greatest concentrations, KN calves being intermediate, and CT having the lowest concentrations. Overall, KN and BA castrated calves presented physiological and behavioral changes associated with acute pain; however, 2-mo-old BA calves presented the fewest behavioral changes and no physiological changes associated with acute pain compared to CT calves.

Deviations in behavior and productivity data before diagnosis of health disorders in cows milked with an automated system.

To explore potential changes in behavior and productivity useful for early detection of health disorders in cows milked with automated milking systems (AMS), we collected longitudinal data throughout lactation of 57 dairy cows housed in a freestall barn with an AMS. Health problems were recorded, including subclinical ketosis (SCK; n = 19), metritis (n = 11), hoof disorders (n = 14), pneumonia (n = 7), and displaced abomasum (DA; n = 5). Data on rumination, activity, milking frequency and yield, and lying behavior were recorded electronically. Using repeated-measures mixed linear regression models, these data were analyzed for the days before the day of diagnosis/treatment (d 0) for each disorder separately, controlling for days in milk and parity. Analyses were performed between the day on which each outcome variable deviated significantly from baseline (up to d -14) and the day before diagnosis (nadir at d -1, before treatment and recovery). Outcomes tested were 3-d rolling averages of milk yield, milking frequency, and AMS supplement intake, in addition to daily rumination time (DRT), body weight, milk temperature, activity (measure of head/neck motion), and 3 lying behavior variables. From d -8, -6, and -5 before diagnosis of DA, SCK, or pneumonia, respectively, DRT declined by 45, 25, and 50 min/d. From d -14 to -1 before diagnosis of hoof disorders, DRT declined by 3 min/d. Body weight declined from d -4 before pneumonia (-14 kg/d) and metritis (-13 kg/d), from d -6 before SCK (-10 kg/d), and from d -5 before hoof disorders (-5 kg/d). Milk yield declined by 4.4 and 4.1 kg/d from d -4 before DA and pneumonia diagnoses, respectively, and by 1.2 kg/d from d -5 before SCK diagnosis. Activity levels declined before diagnosis of DA, pneumonia, SCK, or metritis. Lying behavior changed before diagnosis of DA, pneumonia, or metritis. Our results provide evidence that rumination behavior often deviated before milk yield and that several variables could contribute to earlier or automated identification of disorders. Behavior and productivity changed differently in association with various health disorders, suggesting the potential to distinguish among health problems. These variables merit further investigation in larger studies of cows milked with AMS.

Management practices associated with stress in cattle on western Canadian cow-calf operations: A mixed methods study.

Handling, weaning, and euthanasia are some of the most stressful practices performed on cow-calf operations. Although strategies to minimize stress exist, their use on western Canadian cow-calf operations is unknown. The objectives were to describe current stress-associated practices on western Canadian cow-calf operations, describe producer and operation demographics associated with the use of nonabrupt weaning methods, and explore producer perceptions toward these practices. A questionnaire focusing on stressful management practices was delivered to 109 cow-calf producers in western Canada. Fifteen respondents were purposively selected for individual interviews. The majority of producers reported calves less than 1 wk of age were handled by manual restraint (87%) and those older than 1 wk of age were handled using a cattle squeeze or table. Most producers performed abrupt weaning (70%). Interviewees often mentioned that cost and logistics were major factors in deciding on a weaning strategy. Pasture availability and facilities were viewed as constraints toward the adoption of a nonabrupt weaning method. Animal stress was considered, as producers expressed concern that nonabrupt weaning methods may cause increased stress because of the additional handling required. Producers conveyed that animal age was a major factor that impacted weaning stress and that improved animal performance might motivate them to adopt a nonabrupt weaning strategy. Producers also expressed reluctance to change previously successful traditional approaches. Of respondents, 13% did not euthanize cattle on farm and 8% did not confirm death. Producers interviewed reported that the decision to euthanize cattle on farm was difficult and that veterinary advice was often considered. Factors that influenced their decision to euthanize included the animal's likelihood of recovery and degree of pain and distress. Finally, producers explained that they considered whether the animal was salvageable and able to be transported. Identification of common methods of handling provides focus for future research to determine optimal handling strategies. Identified barriers to nonabrupt weaning may be addressed through research, extension, or policy to encourage the adoption of weaning methods that could improve animal welfare. Confirmation of death after euthanasia was identified as an area that needs to be addressed by producer education to minimize animal stress during on-farm euthanasia.

Cow-level associations of lameness, behavior, and milk yield of cows milked in automated systems.

This study evaluated differences in behavior and productivity between lame and nonlame cows in herds with automated milking systems (AMS). We monitored 30 cows per herd on 41 farms with AMS in Canada (26 herds in Ontario and 15 herds in Alberta). During a 6-d period, milking data (n = 1,184) and lying behavior data (n = 1,209) were collected from cows on 41 farms. Rumination behavior (n = 569) and activity (n = 615) data were available for cows at 22 farms. Locomotion was scored using a numerical rating system (NRS; 1 = sound; 5 = extremely lame). Cows were defined as clinically lame with NRS ≥ 3 (n = 353, 29%) and nonlame with NRS < 3 (n = 865, 71%). Greater parity, lower body condition, and lower environmental temperature were factors associated with lameness. When accounting for other factors, lame cows produced 1.6 kg/d less milk in 0.3 fewer milkings/d. Lame cows were 2.2 times more likely to be fetched more than 1 time during the 6-d period and spent 38 min/d more time lying down in bouts that were 3.5 min longer in comparison with nonlame cows. As the number of cows per AMS unit increased, the frequency of milkings and refusals per cow per day decreased and cow activity increased. For each 13.3-percentage-point increase in freestall stocking density (cows per stall), daily lying time decreased by 13 min/d and cows were 1.6 times more likely to be fetched more than 1 time during the 6-d period. There was no difference in daily rumination or activity between lame and nonlame cows or in night:day rumination time, but lame cows had greater night:day activity ratios. This study supports the growing knowledge that lameness has negative effects on milk production, voluntary milking behavior, and lying behavior of cows in herds with AMS. These results may help dairy producers gain a better appreciation of the negative effects of even moderate cases of lameness and may help motivate them to improve their lameness monitoring and treatment protocols.

Management practices associated with pain in cattle on western Canadian cow-calf operations: A mixed methods study.

The implementation of on-farm pain mitigation strategies is dependent on feasibility and importance to producers. Currently, there is a lack of information regarding adoption of management practices associated with pain in cattle within the Canadian beef industry. The objective of this mixed methods study was to describe pain-associated practices implemented on farm and producer perceptions toward pain mitigation strategies. A questionnaire about calving management and calf processing was delivered to 109 cow-calf producers in western Canada. In addition, 15 respondents were purposively selected based on questionnaire responses to participate in individual semistructured, on-farm interviews. The prevalence of pain mitigation strategies used for dystocia and cesarean section by respondents were 46 and 100%, respectively. The majority of operations reported castrating and dehorning calves before 3 mo of age (95 and 89%, respectively). The majority of operations did not use pain mitigation strategies for castration and dehorning (90 and 85%, respectively). Branding was practiced by 57% of respondents, 4% of which used pain mitigation. Thematic content analysis revealed that producers' perception of pain were influenced by what they referred to as "common sense," relatability to cattle, visual evidence of pain, and age of the animal. Factors that influenced participant rationale for the implementation of pain mitigation practices included access to information and resources, age of the animal, benefit to the operation, cost and logistics, market demands, and personal conscience. Overall, management practices were generally in compliance with published Canadian guidelines. Results of this study may provide direction for future policy making, research, and extension efforts to encourage the adoption of pain mitigation strategies.

Effect of transitioning to automatic milking systems on producers' perceptions of farm management and cow health in the Canadian dairy industry.

Automatic milking systems (AMS), or milking robots, are becoming increasingly common, but there is little documentation of how AMS have affected farms as a whole and what challenges and benefits producers are experiencing during their transition to AMS. The objective of this national survey was to document the effect of transitioning to AMS on producer perceptions of change in housing, farm management, and cow health. In total, 217 AMS producers were surveyed from 8 Canadian provinces. Median time since transition for respondents was 30 mo. The mean number of lactating cows per robot was 51 cows, with a median of 2 AMS units per farm. Fifty-five percent of producers built a new barn to accommodate the AMS. Changing housing systems was necessary for 47% of producers, not necessary for 50%, and not applicable to 3% (as the AMS farm was their first farm). Cleaning and feeding practices remained the same. Overall, farms increased herd size from a median of 77 to 85 lactating cows with the transition to AMS. After the transition to AMS, 66% of producers changed their health-management practices. Producers reported either a decrease or no change in rate of clinical mastitis. Reports on change in rate of lameness and total bacterial count varied. Conception rate was reported to have increased for 63% of producers. Culling rate was perceived to have stayed the same for 59% of producers. Overall, producers perceived their transitions to AMS as successful. Findings from this project provide a benchmark of the effects of AMS on important aspects of Canadian dairy farming, as well as provide producers, AMS manufacturers, veterinarians, and dairy advisors with more detailed knowledge on what to expect when transitioning to AMS.