Calf welfare and mortality in US and Canada similar but different
Similarities and difference exist in calf production in the US and Canada.
By Dr. Al Kertz, AndhilThe United States of America (US) and Canada dairy industries have some similarities, but also some differences. In 2022, there were 27,932 licensed dairy farms in the US with 9,403,000 cows for 337 cows per herd and averaged annually 24,087 lb milk per cow (Geiger 2023). By contrast, in Canada in 2022 there were 972,300 cows on 9,739 farms with about 100 cows per herd which averaged 9,700 liters or about 21,000 lb per cow annually (Canada dairy industry 2022). Thus, the major difference is smaller herd size in Canada due to their supply management program.
With this as background, a comparison within these countries’ dairy population was done of calf management and welfare (Roche et al., 2023). This was done primarily by a group at the Ontario Veterinary College which along with others in animal science at the University of Guelph have done major beneficial studies related to calves. The US has had periodic surveys done of its dairy population under the National Animal Health Monitoring System (NAHMS). Canada did a similar National Dairy Study (NDS) in 2015 versus the last NAHMS survey in 2014. Thus, this article will focus on comparative data from those two surveys (Roche et al., 2023).
Calves born dead are usually considered to be those born dead or within the first 24 hours of life. I have noted this category in the past has been largely unrecognized and/or poorly recorded (Kertz 2016, Kertz 2019).
This was recorded in the 2014 NAHMS survey as 5.6% versus 8.1% in the 2007 NAHMS survey. However, in published studies which I have reviewed it ranged from 10 to 20%. In the NDS survey it was 4.9%. Maybe this indicates progress made since older published studies. The Gold Standard of the Dairy Calf and Heifer Association (DCHA 2016) is <10%. A major cause of calves born dead is dystocia. This is exacerbated by large calves, poor heifer development, and fat heifers or cows due to restricted birth canal via fat deposits in that area.
Bull calves which are typically larger than heifer calves, first calvings, and not using calving ease sires are also related to this issue. The use of sexed semen on first-calf heifers and beef semen on many dairy herds on their lower producing cows also help mitigate this problem.
On the other hand, “pulling” calves too early in birth or when not necessary increases this problem. Preweaned calf mortality in NAHMS surveys has averaged 8.4% in 1991, 11.0 in 1996, 8.7 to 10.5 in 2002, 7.8 in 2007, and 6.4 in 2014 NAMHS data versus NDS data of 6.4% in 2015. The DCHA Gold Standard is for <3% mortality.
Roche et al. (2023) identified barriers to lowering this mortality as:
• Lack of knowledge about the best management practices for calf care and prioritization of labor and time resources toward the milking herd were major barriers to good calf care. This was found to be the case in Ontario.
• It is important to note that although these barriers are present on Ontario dairy farms, they may not be consistent in the United States, where farm sizes and availability of labor are different. Hence, future studies should be encouraged in the United States to further understand barriers faced by producers.
Not discussed is an issue with calves which survive but are negatively impacted, I found this out when I was once asked by a commercial calf and heifer operation to find out why calves from one dairy farm did not do as well in his operation as calves from another dairy in the same geographic area and operated by another brother. I was able to visit with the good dairy operation but not with the poorer operation. So, I asked the calf manager at the good operation if she knew why calves did not do as well at the other dairy? Yes, she said because they “pull” every calf!
Euthanasia of calves was studied and found that 72% in the NAHMS survey and 94% in the NDS survey of calves which died did so without assistance. Calves with untreatable conditions or which are not responsive to treatments are prime candidates for proper euthanasia.
Colostrum management covers a wide array of factors. In both studies, from 4 to 5% of produce allowed calves to nurse cows for their first colostrum. That prevents control of when calves first get colostrum, how much is fed, and what its quality is. Generally, calves should be fed 4 quarts colostrum within the first 12 hours after birth and another 2 quarts within the first 24 hours.
In the NAHMS survey, 12.5% fed < 4 quarts, 45.8% fed 4 quarts, 7.6% fed 5 quarts, and 34.1% fed > 6 quarts or more during the first 24 hours. Not reported, but of critical importance is that the colostrum is not contaminated or properly batch pasteurized.
The goal is to have plasma antibody levels with recommended thresholds (Lombard et al., 2020) to reduce morbidity levels, with >40, 30, 20, and <10 % of calves would fall into the passive immunity categories of excellent (≥ 25.0 g/L IgG), good (18.0-24.9 g/L), fair (10.0-17.9 g/L), and poor (< 10.0 g/L), respectively.
Housing was individual for preweaned calves at 62% in Canada and about 67% in the US. In Canada, respondents who housed calves in groups, 31% housed calves in pairs, 59% housed calves in a maximum group size of 3 to 10, and 10% housed calves in a group size of >10 (Winder et al., 2018a).
In NAHMS, of the 21.9% of respondents that housed calves within groups, 5.9% reported housing calves in groups outside or in groups with outdoor access and 16% reported housing calves in groups inside (number per group was not defined).
Some studies have found benefits to housing calves in pairs or groups while others have raised concerns about higher incidence of respiratory disease. Authors stated: Additional research into approaches to identify and manage disease in social housing systems could spur a change in the housing provided to calves in the US and Canadian dairy industries.
Milk/milk replacer feeding was in Canada mean maximum amount fed that was offered to calves per day was 8.2 L (Winder et al., 2018a), with 33% of producers offering ≤6 L daily. In the US, the daily amount of milk fed was broken down into the following categories: 3.1% for < 4 quarts, 53.3 % 4-5 quarts, 21.3% for 6-7 quarts, 16.2 % for 8-9 quarts, and 6.1% ≥ 10 quarts. Average amount fed was 4 quarts daily in 2007 NAHMS but that increased by 50% to 6 quarts in the 2014 NAHMS survey.
While calves may benefit by feeding more milk/milk replacer, this must also include the inverse relationship to calf starter intake. If starter intake is not adequate for 2 to 3 weeks prior to weaning, and not with a not well—texturized starter fed, a slump or reduced daily gain can result in the month after weaning. In the NAHMS study by Urie et al., (2018), Holstein calves gained 1.61 lb daily prior to weaning but decreased to 1.32 lb. after weaning.
Dehorning or disbudding was the final area discussed. In the US and Canada organizations have mandated in their quality assurance programs the use of pain control when disbudding and dehorning, which will encourage greater uptake of pain control. But the authors state: there remains a need to understand the barriers and perceptions of pain control use in both Canada and the US to further identify ways to encourage uptake.
A good discussion describing calf mortality, the lack of good consistent records, and how to mitigate calf mortality can be found in this recent review (Umana Sedo et al., 2023).
The Bottom Line
Preweaned calf mortality has decreased in both the US and Canada to around 6% in most recent national surveys. But when stillbirths are added that mortality essentially doubles. Colostrum management, housing, and milk/milk replacer feeding have improved, but further improvements are possible, especially in starter fed, and should be sought.
References
Canada’s dairy industry at a glance. 2022. Canada's dairy industry at a glance - agriculture.canada.ca; Number of farms, dairy cows and dairy heifers - agriculture.canada.ca
DCHA (Dairy Calf and Heifer Association). 2016. Gold standards. Accessed May 15, 2021. https://calfandheifer.org/gold-standards/
Geiger, Corey, 2023. U.S. dairy 2022 statistics. Hoards Dairyman, March, p. 133.
Kertz, A. F. 2016. Stillbirths are a largely unrecognized problem on dairy operations. Feedstuffs, January 15, p. 2021.
Kertz, Alois F. Dairy Calf and Heifer Feeding and Management—Some Key Conceptsand Practices. Outskirts Press, July 31, 2019, 166 pages. https://outskirtspress.com/dairycalfandheiferfeedingandmanagement
Lombard, J., N. Urie, F. Garry, S. Godden, J. Quigley, T. Earleywine, S. McGuirk, D. Moore, M. Branan, M. Chamorro, G. Smith, S. Shivley, D. Catherman, D. Haines, A. J. Heinrichs, R. James, J. Maas, and K. Sterner. 2020. Consensus recommendations on calf- and herd-level passive immunity in dairy calves in the United States. J. Dairy Sci. 103:7611–7624.
Roche, S, D. L. Renaud, C. A. Bauman, J. Lombard, D. Short, J. Saraceni, and D. F. Kelton. 2023 Calf management and welfare in the Canadian and US dairy industries: Where do we go from here? J. Dairy Sci. 106:4266-4274.
Umaña Sedó, S. G., C. B. Winder, and D. L. Renaud. 2023. Graduate Student Literature review: The problem of calf mortality in dairy farms. J. Dairy Scie 106:7164–7176.
Urie, N. J.,J. E. Lombard, C.B. Shivley, G.A. Kopral, A. E. Adams, T. J. Earleywine, J. D. Olson, and F.B. Garry. 2018. Preweaned heifer management on US dairy operations: Part I. Descriptive characteristics of preweaned heifer raising practices. J. Dairy Sci. 101:9168-9184.
USDA-APHIS. 2014. About NAHMS. Accessed May 7, 2021. https://www.aphis.usda.gov/aphis/ourfocus/animalhealth/monitoring-and[1]surveillance/nahms/about
Winder, C. B., C. A. Bauman, T. F. Duffield, H. W. Barkema, G. P. Keefe, J. Dubuc, F. Uehlinger, and D. F. Kelton. 2018a. Canadian National Dairy Study: Heifer calf management. J. Dairy Sci. 101:10565–10579.
