A randomized controlled trial investigating the effect of transport duration and age at transport on surplus dairy calves: Part I. Impact on health and growth

Dairy farm management factors associated with clinical observations in young dairy calves sold at auction markets in Québec, Canada: A cross-sectional study

In Québec, Canada, nonreplacement calves are generally sent at a young age to auction markets to be sold for veal or dairy beef production. Various clinical observations found during the calves' journey, either at an auction market or on arrival at a calf raiser farm, have been associated with increased risk of morbidity, such as dehydration or umbilical problems. The objective of this cross-sectional study was to quantify associations between calf raising management strategies at the dairy farm level and clinical observations at auction markets during sale. For this purpose, during 8 different sale days, the 2 largest auction markets in Québec were visited, and all calves sold on those days were systematically examined. The number of clinically relevant findings (CRF) present per calf (among presence of umbilical cord, wet umbilical area, umbilical pain, umbilical swelling, persistent cervical skin fold ≥2 s, sunken eyes, eye or nasal discharge, ear drop, limb anomaly, emaciation or dirty hide) was recorded. After the sale, farm owners were contacted to answer a specific questionnaire on calf management. The total number of CRF from all sold calves from the same farm (dependent variable) was modeled using Poisson multivariable regression, with questionnaire answers as potential covariates and the number of calves sold per farm during the observation period as an offset. The questionnaire was completed during a standardized phone call and focused on farm characteristics and characteristics of calves sold, including calving management, calf care at birth, nutrition, housing, and transportation. A total of 3,656 calves from 1,349 different sellers were examined. The questionnaire information was obtained from 409 different farms representing 847 calves. The median number of calves sold per farm was 2 (range: 1-19). The umbilical cord was visually present in 376 calves (44%). Among the most commonly observed CRF, eye discharge (n = 290, 34%), umbilical swelling (n = 144, 17%), and presence of dehydration signs (persistent cervical skin fold ≥2 s [n = 111, 13%] or sunken eyes [n = 83, 9.8%]) were the most commonly reported anomalies. According to the final multivariable Poisson regression model, the incidence rate ratio (IRR) of CRF for farms that sold calves at a mean age <8 d was higher than for farms that sold calves at a mean age of >10 d (IRR = 1.21, 95% CI: 1.04-1.41). The IRR was also higher for farms that did not give colostrum to calves within 1 h following birth compared with calves receiving colostrum within 1 to 2 h (IRR = 1.73, 95% CI: 1.24-2.49), 2 to 6 h (IRR = 1.48, 95% CI: 1.06-2.14) and more than 6 h (IRR = 1.59, 95% CI: 1.06-2.44) after birth. The IRR were higher for farms using milk replacer to feeding sold calves versus raw milk (IRR = 1.2, 95% CI: 1.06-1.37) and higher for farms where calves typically receive their last meal >3 h before transportation to the auction market versus calves receiving their last meal <1 h before transportation (IRR = 1.26, 95% CI: 1.04-1.53). This study provides interesting insight into farm practices that are associated with an improved clinical status of nonreplacement calves sold at auction markets for veal and beef meat.

Observational study: effect of varying transport durations and feed withdrawal on the physiological status and health of dairy calves

Long-distance transport and associated fasting of unweaned calves have the potential to compromise the animals' welfare. This observational study aimed to determine how transport and fasting durations impacted the physiology and health of 115 transported calves in three transport groups; IRE (n = 20, mean age 29.8d; short road transport (~ 29 h incl. resting time) and short feed deprivation (~ 11 h)), INT (n = 65, mean age 24.9d; long road/ferry transport (~ 79 h incl. resting times) and long feed deprivation (~ 28 h and 25 h)), and NLD (n = 30, mean age 17.7d; short road transport (~ 28 h incl. resting time) and long feed deprivation (> 18 h)). All calves travelled through an assembly centre. Each calf was blood sampled (arrival at destination farm, 1-week and 3-weeks post-arrival), health scored (arrival, 1, 3, 7, 8, 20d post-arrival) and weighed (farm/mart of origin [IRE and INT only], arrival, and 3-weeks post-arrival). (Generalised) linear mixed models were used to analyse differences in blood variables, weight, and health scores on arrival and during recovery (all other timepoints). Despite differing transport durations, both INT and NLD calves exhibited glucose, beta-hydroxy-butyrate, non-esterified-fatty-acids and sodium levels outside reference limits upon arrival, which were different from values observed in IRE calves (p < 0.05). Lactate and potassium were above reference range for INT calves on arrival, and higher than in IRE and NLD groups (p < 0.05). One- and three-weeks post arrival, most variables returned to within reference ranges, and differences between groups were minimal and not clearly associated with either transport duration or fasting during transport. Health scores did not differ between transport groups at arrival, and differences were minimal during the three-week recovery period. INT calves lost more weight during the journey than IRE calves (p < 0.01), while INT and NLD calves gained similar weight in the 3-weeks post-arrival, but less than IRE calves (both p < 0.01). Overall, changes in the physiological status of calves post transport appeared to relate more to the duration of feed deprivation than to the duration of transport, except for potassium and lactate (muscle fatigue), which were impacted more for INT calves. Most variables showed clear signs of recovery to within reference levels for all groups within three weeks. Minimizing the duration of feed deprivation during transport should be a key consideration for the dairy industry to reduce the impact of transport on calf welfare.

A randomized controlled trial evaluating the effect of providing a rest period during long-distance transportation of surplus dairy calves: Part II. Effect on hematological variables

The objective of this randomized controlled trial was to determine if providing a rest stop including provision of feed and water between periods of continuous transportation mitigates the effect of long-distance transportation on markers of energy status and hydration in calves transported by road for 16 h. This study was conducted between September 2022 to January 2023 and included male and female Holstein and crossbred dairy calves ≥7 d old from 2 commercial dairy farms in Ontario, Canada (n = 96). On the day before transportation, calves were enrolled and randomly assigned to one of 2 treatment groups: (1) continuous transportation by road for 16 h or (2) 8 h of transport, 8 h of rest, and a further 8 h of transport to a single calf-raising facility. Calves that received a rest stop were fed 2 L of milk replacer at the time of unloading for the rest period and again immediately before reloading for the second leg of the journey. Blood samples were collected before and after transportation as well as daily for 3 d following arrival to the calf-raising facility. Serum was analyzed for concentrations of BHB, nonesterified fatty acids (NEFA), haptoglobin, and creatine kinase, and acid-base disturbances were evaluated within 1 h of collection of whole blood to assess glucose, sodium, potassium, ionized calcium, hematocrit, hemoglobin, pH, base excess, partial pressure of oxygen, total carbon dioxide, bicarbonate, partial pressure of carbon dioxide, and oxygen saturation. Mixed linear regression models with repeated measures were built to assess the effect of treatment group, age at transportation, breed, and sex on these parameters. Immediately after transportation, calves that received the rest period had lower BHB (-68.04 μmol/L, 95% CI: -99.59 to -36.49), NEFA (-0.14 mmol/L, 95% CI -0.22 to -0.07), and sodium (-1.10 mmol/L, 95% CI = -2.18 to -0.02), and higher glucose (0.48 mmol/L, 95% CI = 0.21 to 0.74), potassium (0.27 mmol/L, 95% CI = 0.11 to 0.43), ionized calcium (0.06 mmol/L, 95% CI = 0.03 to 0.08), and oxygen saturation (8.76%, 95% CI = 1.61 to 15.91) compared with calves that were continuously transported for 16 h. Additionally, calves transported between 11 and 12 d old had lower hematocrit (-1.22%, 95% CI = -2.19 to -0.25), hemoglobin (-3.07 g/L, 95% CI = -5.70 to -0.43), haptoglobin (-0.13 g/L, 95% CI = -0.23 to -0.02), and potassium (-0.13 mmol/L, 95% CI = -0.22 to -0.04) and higher sodium (0.83 mmol/L, 95% CI = 0.03 to 1.63) than 7 to 8 d old calves. Furthermore, calves that were 13 to 24 d old at transport had lower haptoglobin (-0.16 g/L, 95% CI = -0.27 to -0.06) and potassium (-0.14 mmol/L, 95% CI = -0.23 to -0.05), and higher sodium (1.02 mmol/L, 95% CI = 0.22 to 1.82) and ionized calcium (0.02 mmol/L, 95% CI = 0.002 to 0.035) compared with calves transported at 7 to 8 d old. The results of this trial demonstrate that a rest period improves energy status upon arrival to a calf-raising facility, suggesting that the benefit of a rest period may be mostly related to the provision of mid-journey milk meals.

A randomized controlled trial evaluating the effect of providing a rest period during long-distance transportation of surplus dairy calves: Part I. Effect on health, growth, and activity

The objective of this randomized controlled trial was to determine whether providing a rest period to surplus calves transported for 16 h reduced the effect of long-distance transportation on health, growth, and activity after arrival to a calf-raising facility. Between September 2022 to January 2023, 6- to 24-d-old surplus calves were randomly assigned to one of 2 treatment groups: (1) continuous transportation by road for 16 h (n = 86) or (2) 8 h of transport, an 8 h rest period, then a further 8 h of transport to a single commercial calf-raising facility in Ontario, Canada (n = 84). Calves that received the rest period were fed 2 L of milk replacer at the time of unloading for the rest period and again before reloading for the second leg of transportation. Calves were weighed before and after transportation and once weekly until they left the calf-raising facility at 11 wk after arrival. Additionally, fecal consistency and respiratory health were assessed immediately before and after transportation, as well as twice daily following arrival. The odds of abnormal fecal and respiratory scores were assessed with mixed effects logistic regression models, whereas Cox proportional hazards models were used to evaluate the hazard of treatment for diarrhea and respiratory disease. To evaluate weight loss during transportation, ADG, lying bouts, and steps, mixed linear regression models were used. Furthermore, mixed logistic regression models with repeated measures were built to assess associations with the odds of having a sunken flank and prolonged skin tent. There were no statistical differences in the odds of abnormal fecal or respiratory scores or the treatment for diarrhea between treatment groups; however, there was evidence that calves that received a rest period had a higher hazard of treatment for respiratory disease. Calves >10 d old had reduced odds of having an abnormal respiratory score and calves 13 to 24 d old had lower odds of arriving with a prolonged skin tent, lower odds of abnormal fecal score, and reduced hazard of treatment for diarrhea compared with calves that were 6 to 8 d old at transportation. During transportation, calves that received a rest period lost less weight than continuously transported calves. With respect to ADG over the 77-d study, an interaction between age at transport and treatment group was identified where calves aged 9 to 10 d old and receiving a rest period had higher ADG compared with calves that were 9 to 10 d old and not receiving a rest period. As for calf activity, calves receiving an rest period spent more time lying on the day after transportation compared with calves that were continuously transported. The results of this trial show few differences in the health and growth of calves having a rest period compared with those that underwent continuous transport. Furthermore, calves receiving a rest period may arrive more fatigued than calves that arrive at their destination in a shorter period of time overall. Transporting calves at older ages presents an opportunity to reduce the effect of long-distance transportation on subsequent health, growth, and activity.

Transportation conditions of calves upon arrival at major livestock auction markets in Québec, Canada

The objective of this cross-sectional observational study was to describe the transport conditions of calves at the time of their arrival at the 2 major livestock auction markets in the province of Québec, Canada, and to identify characteristics that affect bedding cleanliness. A particular emphasis was placed on the transport environment of young dairy calves commonly being marketed for veal production. During 4 d per auction site (n = 2 sites), 2 d in summer and 2 d in winter, the descriptive characteristics including type of transports, number of calves per transport, separation from other transported animals, as well as presence of ventilation sources (e.g., open holes allowing natural ventilation), bedding, and bedding cleanliness, were determined. A total of 507 different transports were included, representing a total of 4,054 calves sold during these 8 d. The vast majority of calves (95% [n = 3,845]) were transported by commercially designed trailers (long commercial trailers (n = 358; 70.6% of all transport types), short commercial trailers (n = 62; 12.2%), or multideck trailers (n = 15; 3%). A minority of calves (5%) were either transported by homemade trailers (n = 30; 5.9% of transport) or other types of transports (n = 42; 8.3%). The presence of any ventilation source in the calves' transportation area was observed in 86% of transports and increased in summer versus winter (odds ratio: 2.75 [95% CI: 1.58-4.79]). Bedding was present in 96% of evaluated transports. The majority (68%) of calves' transport flooring area was considered clean, with less than 33% of the calves' area soiled with manure. The dirtiness of calves' transport flooring area was lower in winter than in summer (odds ratio = 0.63 [0.43-0.92]) and in site B than in site A (odds ratio = 0.57 [0.38-0.94]). This study gives interesting insight into transportation and unloading conditions of surplus calves in commercial auction markets.

Awareness and perceived barriers to the adoption of best management practices for the transportation of lactating cull dairy cows of dairy producers in Ontario

The objectives of this study were to understand dairy farmers' awareness and perceived barriers to the implementation of best management practices (BMP) for the transportation of lactating culled cows being moved to auction or abattoir. An invitation to participate was emailed to all dairy farms in Ontario, Canada. Responses to this invitation were used to recruit additional participants through criterion purposive snowball sampling. In total, 28 dairy producers participated in one of 5 semi-structured focus groups. All focus groups were audio recorded, transcribed verbatim, and analyzed with applied thematic analysis. Four themes were identified including 1) transfer of responsibility, 2) interpersonal relationships, 3) juggling priorities, and 4) complexities of long-term planning. While individual participant knowledge varied, participants described misconceptions that other producers held surrounding transport duration and distances, or the number of possible sales points for lactating culled cows. Participants did not agree whether the producer's responsibility ended once the cow left their property or if shared responsibility remained among all stakeholders from the farm to the final destination. Participants discussed the importance of existing trusted relationships with local cattle transporters and veterinarians to ensure information on best practices are shared. Participants also discussed how business pressures (e.g., production demands, space limitations) often challenge their ability to dry off lactating cows before transport; however, participants mentioned the degree of milk production may influence the destination of their animal (e.g., direct to slaughter for animals with high milk production). Some participants described a dynamic balance between business pressures and the potential for declining welfare of the animals under consideration to be culled during lactation. Participants posited that producers who did not prioritize proactive herd management and producers nearing retirement had limited long-term planning for culling individual cows, which might lead to transport of vulnerable or unfit animals. Finally, the lack of access to transportation direct to local slaughter was identified as an important barrier to adherence with the BMP for cull cows. In summary, many participants did not have an accurate understanding of what happens to cull cows after departing the farm and were unsure if they maintained a level of responsibility for an animal after being transported from their farm. Given the priority placed by participants on trusted interpersonal relationships, greater availability of peer-to-peer training of farmers and professional accreditation of animal transporters in addition to structural changes to increase local slaughter capacity may increase implementation of BMP and enhance lactating cull cow welfare.

Investigating nutritional strategies during a rest period to improve health, growth, and behavioral outcomes of transported surplus dairy calves

The objective of this study was to investigate the effects of feeding surplus dairy calves a milk replacer (MR) or one of 2 different oral rehydration solutions (ORS) during a midtransportation rest period on metabolic and clinical health indicators, growth, and behavioral outcomes after arrival at a calf-raising facility. Surplus dairy calves (n = 128) were transported in 4 cohorts from February to July 2022 for 12 h to a holding facility, rested for 8 h, then transported for an additional 6 h to a calf-raising facility. Upon arrival at the holding facility, calves were randomly assigned to 1 of 3 treatments: MR (n = 43), a high-sodium ORS developed for diarrhea (ORS-D; n = 43), or a high-potassium ORS developed for transportation (ORS-T; n = 42). The exact age of calves at transportation was unknown; however, all calves were less than 14 d of age. Calf BW at enrollment was 43.9 ± 5.9 kg, 43.7 ± 6.5 kg, and 45.0 ± 4.5 kg for calves fed MR, ORS-D, and ORS-T, respectively. Calves were fed 2.0 L of their treatment twice, once upon arrival and once before leaving the holding facility. At unloading and reloading at the holding facility, calves were weighed and blood samples were obtained. Calves were also health scored at unloading at the holding facility. After arrival at the calf-raising facility, calves were weighed, health scored, and blood samples were taken. Blood samples were collected at 24 and 48 h and BW was recorded at 24 h, 48 h, 72 h, 5 d, 7 d, 14 d, and at 8 wk after arrival at the calf-raising facility. Calves were also health scored daily for 14 d; health scoring included fecal consistency scoring and evaluating the presence or absence of respiratory disease. Lying time, lying bouts, and activity index were measured during transportation and from 3 d relative to transportation using accelerometers. At arrival to the calf-raiser, calves fed ORS-D had higher concentrations of nonesterified fatty acids (NEFA) and BHB than calves fed MR. Furthermore, calves fed ORS-T had higher concentrations of BHB at arrival to the calf raiser compared with calves fed MR. In the 14 d after arrival at the calf-raiser, there was evidence that calves fed ORS-T had a higher proportion of days with diarrhea and respiratory disease compared with those fed MR. During transportation, calves fed ORS-T had a lower activity index than calves fed MR, suggesting that ORS-T calves had lower overall activity. In addition, on the day of transportation (d 0), ORS-T and ORS-D calves had a lower activity index than calves fed MR. There were no treatment effects on growth outcomes. The results of this study suggest that feeding MR rather than an ORS during a midtransportation rest period could minimize fat mobilization and can potentially improve diarrhea and respiratory disease but does not affect growth outcomes after arrival at calf-raisers.

Association of Bovine Respiratory Disease during the Pre-Weaning Period with Blood Cell Counts and Circulating Concentration of Metabolites, Minerals, and Acute Phase Proteins in Dairy Calves Transported to a Calf Raising Facility

Our objective was to investigate the association of bovine respiratory disease (BRD) occurring within the first 56 days of life with blood cell counts and the circulating concentration of metabolites, minerals, and acute phase proteins throughout the pre-weaning period in dairy calves transported to a heifer raising facility within their first week of life. Data from 305 calves transported from dairies in Minnesota to a calf raising facility in New Mexico within their first four days of life were used in this retrospective cohort study. Blood samples were collected at 7, 17, 34, and 56 days of life for the analysis of blood cell counts, biochemistry, and the concentration of acute phase proteins. Blood urea nitrogen, albumin, GLDH, CK, P, Na, K, Cl, Zn, Hp, SAA, and monocyte counts were associated with BRD status throughout or at least at one of the time points evaluated in this study. In conclusion, several hematological variables were associated with BRD status in dairy calves that underwent transportation stress in early life.

Exploring the effects of transport duration on the fecal microbial communities of surplus dairy calves

Transportation significantly affects the health and welfare of surplus dairy calves, largely due to the various stressors and pathogen exposures encountered during the process. Concurrently, an animal's microbiome is known to correlate with its health status, with stress-induced alterations in the microbiota potentially precipitating various diseases. This study aimed to compare the effects of transportation durations of 6, 12, or 16 h on the fecal microbiota in young surplus dairy calves. We used a randomized controlled design in which surplus dairy calves aged 1 to 19 d from 5 commercial dairy farms in Ontario were allocated into 1 of 3 transportation groups (6, 12, and 16 h of continuous transportation). Health assessments were conducted before, immediately after, and for 2 wk following transportation. Fecal samples were collected before, immediately after, and at 24 and 72 h after transportation and subjected to 16S rRNA sequencing. Alpha diversity metrics showed no significant differences between the 3 transportation groups at any of the sampling time points. Although β diversity metrics revealed no clustering by transportation groups, they indicated significant differences across sampling time points within each group. The overall analysis revealed a total of 22 phyla and 353 genera, with Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria, and Fusobacteria being the most abundant phyla. Bacteroides, Escherichia/Shigella, Lactobacillus, Collinsella, and Bifidobacterium were the most abundant genera. The reduction in Fusobacteria abundance before and after transport was significantly larger in the 16-h transportation group when compared with the 6-h transportation group. We also identified several genus-level and amplicon sequence variation-level taxa that displayed significant differences in their abundances across various transportation groups, observed at all sampling time points investigated. This research identifies microbiota changes due to varying transportation durations in surplus dairy calves, providing a broad understanding of the microbial shifts in surplus dairy calves after transportation across varying durations. Although these variations may not directly correlate with overall calf health or indicate dysbiosis, these results emphasize the importance of further investigating transportation practices to enhance calf health and well-being. Further studies are warranted to elucidate the relationship between microbiota and calf health.

Dairy calf transportation in the United States: Challenges and strategies to improve animal welfare

The objectives of this symposium review are to summarize relevant research and key welfare issues relative to calf transportation and identify strategies to mitigate welfare challenges. An important animal welfare concern across the US dairy industry is the transportation of preweaning calves from the source dairy to a calf-raising facility (e.g., calf ranches, heifer raising facilities, veal operations), auction, livestock market, or directly to slaughter. Millions of calves are transported annually in the United States and calf transport has garnered increased attention. Transportation stressors include limited (if any) access to food and water, commingling, environmental temperature changes, and a variety of handling techniques. Calves in the United States are often transported at an average age of 3 d, and in many cases, less than 24 h of age. Neonates are particularly vulnerable to transportation stressors due to their decreased ability to thermoregulate, underdeveloped immune system, and immature physiologic stress responses. In addition to age, fitness for transport is a key welfare consideration; recent data from the United States demonstrate that some source dairies transport compromised calves (i.e., dehydration, diarrhea, navel inflammation, and so on), leading to important welfare challenges during transportation. Calves arriving at US veal facilities have been reported to be dehydrated, lethargic, hypoglycemic, and may also have poor body condition, navel inflammation, and diarrhea. Thus, there is ample opportunity to target decision-making and producer-focused education not only at the source dairy, but also at each stage of transportation to address critical welfare concerns. In addition, the supply chain and procurement model that influence calf transport practices should be evaluated to determine potential opportunities to improve calf welfare. Here, we provide 5 potential strategies to improve the welfare of transported calves: (1) provide excellent newborn care that "preconditions" calves for transport, (2) assess calves' fitness-for-transport to ensure they can withstand the journey, (3) handle calves with care, (4) wait until calves are older to transport, and (5) reduce transport duration.

Condition of surplus dairy calves during marketing: A cross-sectional study

In North America, surplus dairy calves are sold soon after birth and often marketed through a third party (e.g., live auction, livestock dealer) before entering veal or dairy beef production. Previous work has demonstrated that a percentage of calves have failed transfer of passive immunity (FTPI) and clinical signs of disease on arrival at calf-raising facilities, but little is known regarding calf condition during marketing. The objectives of this cross-sectional study were to (1) estimate the prevalence of FTPI and poor health outcomes in surplus calves on arrival at livestock dealers, and (2) investigate the association between calf-level variables (body weight, sex, source) and health outcomes. Two livestock dealers in Ohio were visited 2 to 3 times per week, with approximately 28 calves enrolled in the study per visit for a total of 1,119 calves. One blood sample per calf was obtained to evaluate FTPI by measuring serum total protein concentrations (using a cutoff <5.1 g/dL). Calves were clinically evaluated for signs of arthritis, broken ribs or tail, dehydration, depression, diarrhea, fever, navel inflammation, and respiratory disease by 2 observers; health outcomes were dichotomized using clinically relevant cut points. Descriptive statistics were used to estimate the prevalence of calves with poor health outcomes. Multivariable logistic regression models were built to investigate the effect of body weight, sex, and source on health outcomes. Nineteen percent (206/1,091) of calves had FTPI.

Preliminary exploration of the health and behavior around the time of transportation of beef × dairy calves and Holstein bull calves 3 days of age or younger in the western United States

In the western United States, it is common practice for dairy and beef × dairy calves to be sold and shipped within the first few days of life, making transportation one of the first challenges that a calf will experience. To date, no published research has examined the effects of calf transport within the western United States. The objectives of this observational study were to describe the health status of calves leaving the source dairy, characterize transportation conditions and calf behavior during transportation, and determine if age at transportation and transportation duration are associated with dehydration, blood glucose and lactate, and behavior. An observational study was performed on 2 source dairies in the western United States. Initial enrollment consisted of dairy bull calves and beef × dairy calves (n = 126 total) across 16 transport cohorts which were sold and transported to separate calf-raising facilities approximately 80 km from the source dairy. Health exams and measurements were performed on all study participants 2 to 3 h before transport and ≤2 h after transport. Two researchers performed health exams using the Wisconsin calf health score, which included clinical respiratory scores, lung ultrasound, and fecal, navel, and joint scores. Hydration status was assessed using skin tent duration. Blood samples were collected and immediately analyzed for blood glucose and lactate using glucose and lactate meters. Accelerometers were attached at the source dairy on ≤10 calves in each of the 16 transport groups to record movement and behavior during transport (n = 90 had accelerometers attached). Results showed that about half of calves (49%) were identified with at least one health abnormality before transport. Researchers found an association between age and dehydration status in which calves <24 h of age were more likely to be dehydrated compared with calves 1 d of age. Additionally over half of the calves (56%) were identified as dehydrated after transport. To the authors' knowledge, this is the first observational study that investigates the effects of transportation on dairy bull and beef × dairy calf health and welfare in the western United States. Our findings support the need for improved management and decision making before transporting calves to reduce the negative effects of transport.

How can better calf care be realized on dairy farms? A qualitative interview study of veterinarians and farmers

Improving health and welfare outcomes for replacement and surplus dairy calves is important for the sustainability of the dairy industry. Dairy farmers and veterinarians hold expertise in calf management and have valuable perspectives on how to practically motivate improvements. The objective of this study was to determine strategies that could improve the care calves receive on dairy farms from the perspective of dairy farmers and their herd veterinarians. Two veterinary clinics specializing in dairy practice in British Columbia, Canada, and 21 of their client dairy farms participated in the project. Following a meeting in which calf colostrum management was discussed between farmers and their herd veterinarian, participant interviews were conducted. Separate interviews were conducted for the farmers (n = 27 farmers from 21 farms) and their herd veterinarians (n = 7, with 1 to 5 farms that each vet worked with enrolled in the study) using tailored semi-structured question guides. Interviews (n = 42) were transcribed and coded following inductive thematic analysis methodology. The themes identified included strategies for farmers, veterinarians, and calf buyers, as well as contexts that influenced the dairy farmers' internal motivation to provide good calf care. Results indicated that farmers could optimize their calf management through fostering engagement of calf care personnel or by enlisting technology. Veterinarians could provide support to farms by being actively involved in calf monitoring, assisting in developing operating protocols, and setting goals, and especially by using farm-specific data to guide their management recommendations. Calf buyers could communicate with and provide accountability to farmers and improve their purchasing strategies to encourage farms to raise more vigorous surplus calves. Farmers' personal values, social networks, and relationships with different dairy industry stakeholders influenced their concern about the standards of their calf care practices. These findings provide guidance on how dairy farmers could achieve or be prompted to achieve improvements in their calf care practices.

Rehydration post-transport: duration of oral fluid therapy on behavior, biochemical measures of hydration, and health of neonatal dairy calves

The objective of this study was to determine the impact of 0, 1, 2, or 3 d of oral electrolyte solutions (OES) following transport on calf behavior, biochemical measures of hydration, and subsequent health. Two cohorts of 60 Holstein bull calves ~3 to 7 d of age were included in this experiment. Calves (n = 30/treatment) were randomized to 1 of 4 treatments on arrival at a calf-raising facility: (1) 1-d OES, (2) 2-d OES, (3) 3-d OES, or (4) no OES (control). Calves were evaluated for signs of arthritis, depression, dehydration, diarrhea, fever, navel inflammation, and respiratory disease on arrival (day 0) and 1, 2, 3, and 7 d after arrival. Blood was obtained following each examination to assess biochemical measures of hydration, including serum electrolytes, glucose, hematocrit, lactate, pH, and serum total protein (STP). Calves were fitted with 3D accelerometers attached to the right hind leg along the metatarsus bone to continuously measure lying time. Linear regression models with Gaussian or Poisson link functions were used to test differences between treatments in blood parameters, as well as disease frequency and behavior, respectively. Calves spent the most time lying immediately post-transport (day 0); however, there was no effect of OES treatment on lying time. On arrival, 90% (95% CI: 84.6% to 95.4%) of calves had mild to moderate dehydration, and there was no significant difference in hydration status across treatments. Mildly dehydrated calves that received 1- and 2-d OES had higher STP concentration compared to the control. Moderately dehydrated calves that received 3- vs. 1-d OES had higher (101.4 vs. 93.7 mmol/L, respectively; P = 0.01) glucose concentration, and 3- vs. 2-d OES (101.4 vs. 96.2, respectively; P = 0.07) calves tended to have higher glucose concentration. The prevalence of failed transfer of passive immunity (STP < 5.1 g/dL) and hypoglycemia (glucose < 4.95 mmol/L) was 26.7% (18.6% to 34.7%) and 76.5% (68.7% to 84.2%), respectively. The frequency of moderate dehydration was lower for calves that received 2-d OES compared to the control (count ratio: 0.4; 0.2% to 0.8%; P = 0.009). These results underline the need for more research on rehydration strategies to help inform calf processing protocols. Future research should investigate preconditioning strategies to minimize the impact of marketing and transport on dairy calves. Continued nutritional-based research is also needed to better support calves' recovery post-transport.

Are regulations addressing farm animal welfare issues during live transportation fit for purpose? A multi-country jurisdictional check

Growing animal welfare concerns have pushed some jurisdictions to strengthen regulations addressing live farm animal transportation, but whether they provide satisfactory levels of protection for animals remains to be shown. Using the recent peer-reviewed literature, we identified four major risk factors associated with live animal transportation (fitness for transport, journey duration, climatic conditions and space allowances) and explored how regulations were structured to prevent animal welfare issues in five English-speaking Western jurisdictions (Australia, Canada, New Zealand, the EU and the USA). All legally binding federal regulations were systematically reviewed and compared. Whether these rules were fit for purpose was assessed using the relevant peer-reviewed scientific literature. Our findings indicate the majority of regulations in most jurisdictions are often insufficient or too vague to be deemed fit for purpose. All five jurisdictions fall short in guaranteeing adequate protection to livestock during transport. Using recent changes as well as future policy proposals under discussion, we identify future directions that could form the basis for regulatory changes that may significantly improve the welfare of farm animals during transportation.

Effects of transportation duration on lying behavior in young surplus dairy calves

Surplus dairy calves are commonly transported long distances from dairy farms to calf-raising facilities and livestock auctions. Current calf transportation research mainly describes physiological changes resulting from transportation. However, few studies have described the effects of transportation on calf behavior. The main objective of this study was to determine the effects of different durations of transportation (6, 12, and 16 h) on lying time and bouts in surplus dairy calves. A secondary objective of this study was to investigate whether calf age affected lying behavior around transportation. Surplus dairy calves (n = 175) were transported in 7 cohorts from 5 commercial dairy farms in Ontario to a single veal facility. On the day of transportation (d 0), calves were randomly assigned to 1 of 3 treatment groups: (1) 6 h (n = 60), (2) 12 h (n = 58), or (3) 16 h (n = 57) of continuous transportation by road. Calf lying and standing behaviors were recorded using HOBO data loggers (Hobo Pendant G Acceleration Data Logger, Onset Computer Corporation). Daily lying time (h/d) and bouts (no./d) were assessed from -1 to 3 d relative to transportation. The total time spent lying during transportation was assessed as the percentage of time lying (min lying/total min on the trailer × 100) from the time each calf was loaded onto the trailer until the time each calf was unloaded at the veal facility (n = 167). On the day of transportation (d 0), calves transported for 12 and 16 h spent less time lying (6 h: 17.1 h/d; 12 h: 15.9 h/d; 16 h: 15.0 h/d) and had more lying bouts (6 h: 21.9 bouts/d; 12 h: 25.8 bouts/d; 16 h: 29.8 bouts/d) compared with those transported for 6 h. On the day after transportation (d 1), calves transported for 16 h spent more time lying down than calves transported for 6 h (19.9 h/d vs. 18.8 h/d, respectively). In addition, during transportation, calves transported for 12 h and 16 h spent 5.8% and 7.6% more time lying down, respectively, than calves transported for 6 h. On each day relative to transportation (d -1 to 3), younger calves (2 to 5 d of age) spent a greater amount of time lying down than older calves (6 to 19 d of age) and, overall, had a greater number of lying bouts. The results of this study suggest that longer durations of transportation influence the lying behavior of surplus dairy calves, resulting in more fatigue during and after the journey and, therefore, potentially have negative implications for calf welfare. Additionally, longer durations of transportation may have greater influence on younger calves than older calves.