The care of surplus dairy calves is a significant issue for the United States and Canadian dairy industries. Surplus dairy calves commonly experience poor welfare as evidenced by high levels of mortality and morbidity, and negative affective states resulting from limited opportunities to express natural behaviors. Many of these challenges are a result of a disaggregated production system, beginning with calf management at the dairy farm of origin and ending at a calf-raising facility, with some calves experiencing long-distance transportation and commingling at auction markets or assembly yards in the interim. Thus, the objectives of this narrative review are to highlight specific challenges associated with raising surplus dairy calves in the U.S. and Canada, how these challenges originate and could be addressed, and discuss future directions that may start with refinements of the current system, but ultimately require a system change. The first critical area to address is the management of surplus dairy calves on the dairy farm of origin. Good neonatal calf care reduces the risk of disease and mortality, however, many dairy farms in Canada and the U.S. do not provide sufficient colostrum or nutrition to surplus calves. Transportation and marketing are also major issues. Calves can be transported more than 24 consecutive hours, and most calves are sold through auction markets or assembly yards which increases disease exposure. Management of calves at calf-raisers is another area of concern. Calves are generally housed individually and fed at low planes of nutrition, resulting in poor affective states and high rates of morbidity and mortality. Strategies to manage high-risk calves identified at arrival could be implemented to reduce disease burden, however, increasing the plane of nutrition and improving housing systems will likely have a more significant impact on health and welfare. However, we argue the current system is not sustainable and new solutions for surplus calves should be considered. A coordinated and holistic approach including substantial change on source dairy farms and multiple areas within the system used to market and raise surplus dairy calves, can lead to more sustainable veal and beef production with improved calf outcomes.

Providing optimal calf care remains a challenge on many dairy farms and has important implications for the future health, welfare, and productivity of male and female calves. Recent research suggests that male dairy calves receive a lower quality of care early in life than female calves, but further investigation is required to determine the factors that influence this disparity. The objectives of this study were to understand dairy producer perspectives on neonatal calf care practices and explore differences between male and female calf care. Overall, 23 dairy producers in Ontario, Canada, participated in 4 focus groups about calf care practices that were recorded and evaluated qualitatively using thematic analysis. Major barriers for good calf care included lack of knowledge about the best management practices for calf care and the prioritization of farm resources toward the milking herd. Some producers also noted that farm infrastructure (particularly during challenging weather) and employee training were important limitations. The economic cost of providing good neonatal calf care was important primarily for male calves and acted as a motivation or a barrier depending on the producer's beliefs about calf care and how they chose to market their calves. The primary source of knowledge producers used to develop calf care practices was their own experience, although many also relied on dairy-industry advisors, most often veterinarians. Producers were motivated by social norms, along with intrinsic pride and obligation to provide good calf care, and these motives were influenced by their emotional state. Producers expressed beliefs about which aspects of calf care are most important-notably colostrum management-and appreciated simple and economical solutions to calf-rearing challenges. Calf care practices were varied, and we identified a diversity of knowledge, motivations, and barriers to adopting best management practices, which sometimes differed between male and female calves. Some producers said that they did not know what happened to their male calves after they left the farm and tended to prioritize the care of female over male calves in subtle ways, such as less timely provision of colostrum. The infrastructure investment and other costs associated with caring for male calves often limited their care, but producers were still motivated to provide adequate care for male calves. These findings represent potential targets for additional research and intervention strategies to improve calf care practices on dairy farms.

Peripheral lymph nodes have been implicated as potential contaminants of ground beef, yet the source and timing of Salmonella lymph node (LN) infection in cattle is still unclear, limiting targeted intervention. Thus, the aim of this study was to leverage the vertical integration of special-fed veal production to identify preharvest environmental exposures, namely livestock trailers or harvest facility holding pens where calves spend 30 min. to 4 hrs, that result in Salmonella LN infection. Ten cohorts of 80-82 veal calves were followed through the harvest process, with environmental samples collected in barns, livestock trailers, and harvest facility holding pens. Mesenteric lymph nodes from 35 calves were then collected at harvest. An additional 25 prefemoral LNs per cohort were pooled. Twelve instances of matching Salmonella serovar between environmental and calf LN isolates within the same cohort were submitted for whole genome sequencing to determine if said exposures resulted in LN infection. Cohort-level Salmonella mesenteric LN prevalence ranged from 0 (0/35) to 80% (28/35) and pooled prefemoral LNs were positive in 3 out of 10 cohorts. Environmental Salmonella prevalence was 22% (13/60), 74% (59/80), and 93% (74/80) for barns, livestock trailers, and harvest facility holding pens, respectively. Multidrug resistance was exhibited environmental and LN isolates. Four instances of Salmonella transmission from trailers and/or holding pens to calf LNs were supported by sequence data. One instance from the livestock trailer, two instances from holding pens, and one instance from either trailer or holding pens were captured with multiple serovars (Agona, Give, and Muenster) transmitted. Further research should evaluate the extent of environmental Salmonella transmission in cattle and if targeted interventions in trailers or harvest facility holding pens could reduce novel Salmonella LN infection in veal calves prior to harvest.

Surplus calves, which consist predominately of male calves born on dairy farms, are an underrecognized source of antimicrobial-resistant (AMR) pathogens. Current production systems for surplus calves have important risk factors for the dissemination of pathogens, including the high degree of commingling during auction and transportation and sometimes inadequate care early in life. These circumstances contribute to an increased risk of respiratory and other infectious diseases, resulting in higher antimicrobial use (AMU) and the development of AMR. Several studies have shown that surplus calves harbor AMR genes and pathogens that are resistant to critically important antimicrobials. This is a potential concern as the resistant pathogens and genes can be shared between animal, human and environmental microbiomes. Although knowledge of AMU and AMR has grown substantially in dairy and beef cattle systems, comparable studies in surplus calves have been mostly neglected in North America. Therefore, the overall goal of this narrative review is to summarize the existing literature regarding AMU and AMR in surplus dairy calf production, highlight the management practices contributing to the increased AMU and the resulting AMR, and discuss potential strategies and barriers for improved antimicrobial stewardship in surplus calf production systems.

Male dairy calves are often sold from the farm of birth within the first few days of life. Research describing the care of male calves is limited, with an emphasis on parsing differences between the care of male and female calves. The aims of this study were to describe dairy producers’ self-reported care practices for male relative to female calves, as well as their perceptions toward male calf care and welfare. Overall, 24 dairy producers in Ohio and Indiana participated in 1 in-person focus group (n = 10) or were individually interviewed (n = 14) using a semi-structured questionnaire with closed and open-ended questions about neonatal calf care and welfare. Discussions were audio recorded and transcribed verbatim. Data from closed-ended questions are described quantitatively, and thematic analysis was used to identify common themes discussed by producers for open-ended questions. A majority of producers described using different care protocols for male and female dairy calves (64%; 9/14 interview participants). Low input care practices were more commonly consistent between male and female calves, such as colostrum protocols (71%; 10/14 interview participants) and navel care (100%; 14/14 interview participants) than more costly treatments. Of the producers that provided disease prevention products to female calves (79%; 11/14 interview participants), only a few also administered them to male calves (27%; 3/11 interview participants). Three major themes were constructed from the open-ended questions, including factors affecting male dairy calf care, attitude toward male calf welfare, and opportunities to improve male dairy calf welfare. Producers described multiple factors that influenced male calf care on the dairy, such as time and money required to care for them. There was divergence in concern among producers about male calf welfare, with some producers expressing concern, particularly for calves slaughtered soon after birth; yet others described feelings of indifference about the topic. Potential ways to improve male calf welfare, including greater sale prices and the involvement in specialized marketing schemes, were suggested by some producers. These findings highlight potential concerns for male calf welfare and ways to improve future care on dairy farms.