{"id":574,"date":"2021-04-02T02:22:44","date_gmt":"2021-04-02T02:22:44","guid":{"rendered":"https:\/\/calftel.local\/?p=574"},"modified":"2024-06-03T00:29:09","modified_gmt":"2024-06-03T00:29:09","slug":"new-recommendations-on-passive-immunity-standards-for-dairy-calves-and-herds","status":"publish","type":"post","link":"https:\/\/calftel.com\/pl\/calf-corner\/new-recommendations-on-passive-immunity-standards-for-dairy-calves-and-herds\/","title":{"rendered":"New Recommendations on Passive Immunity Standards for Dairy Calves and Herds"},"content":{"rendered":"\n

by Kelly Driver<\/em><\/p>\n\n\n

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It is widely recognized that colostrum is the single most important meal<\/a> for newborn dairy calves, delivering essential nutrition, immunoglobulins (Ig) and other important factors vital to setting up a newborn for lifetime success. Highly anticipated new recommendations about passive immunity standards for newborn calves have been published in the August 2020 issue of the Journal of Dairy Science. So, let\u2019s take a look at what research has shown over the years and what the most recent recommendations offer for both individual calves and herd-level goals, as the industry moves again to further improve calf health and reduce morbidity and mortality in young calves.<\/p>\n\n\n\n

The back story.<\/strong><\/p>\n\n\n\n

Passive immunity in dairy calves is evaluated by measuring the serum total protein (STP) or plasma IgG within the first seven days of age. The standard for individual calves to be categorized with successful passive transfer for the past 30 years has been >10 g\/L serum IgG, while failure of passive transfer of immunity (FPT) was a serum IgG concentration <10 g\/L. These levels correlate directly to STP levels of >5.2 g\/dL (pass) and <5.2 g\/dL (fail).These cutoffs were established based on higher mortality rates in calves with serum IgG <10 g\/L.<\/p>\n\n\n\n

Studies have shown.<\/strong><\/p>\n\n\n\n

Research conducted by USDA National Animal Health Monitoring System (NAHMS) in 1991 showed that 41 percent of U.S. dairy calves had failure of passive immunity. With education and outreach, NAHMS reported an improvement to 19.2 percent of calves in 2007 and 13.7% in 2014 studies. Over this same time period, preweaned death rates decreased from 10.8% in 1996 to 6.4% in 2014, but the number of sick calves remained at nearly 30 percent.<\/p>\n\n\n\n

Jason Lombard, DVM, MS at USDA\/NAHMS reported at the 2020 Dairy Calf and Heifer Conference that in the spring of 2018, a group of eighteen U.S. and Canadian calf experts first gathered to scrutinize the 2014 NAHMS calf data, and discuss other published literature to propose new passive immunity standards. The group emphasized that new standards \u201cneeded to be realistic and achievable,\u201d related Lombard to the virtual attendee audience.<\/p>\n\n\n\n

Time for an upgrade.<\/strong><\/p>\n\n\n\n

Research has repeatedly shown that healthier calves have improved rates of gain and feed efficiency, resulting in earlier breeding and calving, along with better first and second lactation milk yields. Studies in both dairy and beef calves have also shown reduced morbidity in calves with higher serum IgG levels. Lombard reported the industry group consensus includes four categories, each with corresponding serum IgG concentrations, serum total protein, and Brix percentages. Additionally, the group recommended the percentage of calves that should fall into each category, based on the 2014 NAHMS calf study.<\/p>\n\n\n\n

New transfer of passive immunity goals for U.S. dairy calves<\/strong><\/p>\n\n\n\n

Category<\/th>Serum IgG categories (g\/L)<\/strong><\/th>Serum total protein level (g\/dL)<\/strong><\/th>Brix level (%)<\/strong><\/th>Farm Level % calves<\/strong><\/th><\/tr><\/thead>
Excellent<\/strong><\/td>> 25.0<\/td>> 6.2<\/td>> 9.4<\/td>> 40%<\/td><\/tr>
Good<\/strong><\/td>18.0 – 24.9<\/td>5.8 – 6.1<\/td>8.9 – 9.3<\/td>– 30%<\/td><\/tr>
Fair<\/strong><\/td>10.0 – 17.9<\/td>5.1 – 5.7<\/td>8.1 – 8.8<\/td>– 20%<\/td><\/tr>
Poor<\/strong><\/td>< 10.0<\/td>< 5.1<\/td>< 8.1<\/td>< 10%<\/td><\/tr><\/tbody><\/table>
Source: Lombard presentation, DCHA 2020 Conference<\/figcaption><\/figure>\n\n\n\n

Lombard\u2019s group went on to provide two colostrum feeding recommendations, based on the results of the NAHMS Calf Component survey, to help dairy producers achieve the new passive immunity recommendations:<\/p>\n\n\n\n