Location: Infectious Bacterial Diseases ResearchTitle: Effect of feeding heat-treated colostrum on risk for infection with Mycobacterium avium subsp. paratuberculosis, milk production and longevity in Holstein dairy cows
|Godden, S - University Of Minnesota|
|Wells, S - University Of Minnesota|
|Donahue, M - University Of Minnesota|
|Oakes, J - University Of Minnesota|
|Sreevatsan, S - University Of Minnesota|
|Fetrow, J - University Of Minnesota|
Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/19/2015
Publication Date: 6/12/2015
Citation: Godden, S.M., Wells, S., Donahue, M., Stabel, J.R., Oakes, J.M., Sreevatsan, S., Fetrow, J. 2015. Effect of feeding heat-treated colostrum on risk for infection with Mycobacterium avium subsp. paratuberculosis, milk production and longevity in Holstein dairy cows. Journal of Dairy Science. 98:5630-5641.
Interpretive Summary: Morbidity and mortality in neonatal calves is a major concern for dairy producers. Evidence suggests that calves can become infected shortly after birth by exposure to pathogens such as Mycobacterium avium subsp. paratuberculosis (MAP), Salmonella, and Mycoplasma in either the feces or milk of infected dams, bedding or cohabitation with other infected animals. These pathogens may be spread to calves through colostrum from sick or infected cows. Some producers have opted to feed colostrum replacers to their calves to avoid the potential spread of disease. However, this is an additional expense that some producers cannot afford. Pasteurization of colostrum is an economical alternative to commercial colostrum products, however, little is known about its long-term effectiveness in reducing morbidity in dairy cows. In the present study, calves in 6 herds in Minnesota were randomly assigned to either heat-treated or fresh colostrum at birth, and followed through their third lactation within the herds. Animals were tested annually for infection with MAP by two diagnostic methods. Results suggested that heat treatment of colostrum did not influence milk production, somatic cell counts, dry-off periods, or culling rates of cows in the herds. More importantly, heat treatment of colostrum did not impact MAP positivity of cows in lactations 1-3. However, feeding heat-treated colostrum did improve passive transfer of IgG and reduced morbidity in the pre-weaning period for young calves, suggesting a key benefit for neonates in the early stages of life.
Technical Abstract: In summer 2007, a randomized controlled clinical trial was initiated on 6 large Midwest commercial dairy farms to investigate the effect of feeding heat-treated (HT) colostrum on transmission of Mycobacterium avium subsp. paratuberculosis and on future milk production and longevity within the herd. Daily on each farm, colostrum was collected from fresh cows, pooled, divided into two aliquots, and then one aliquot was heat-treated in a commercial batch pasteurizer at 60ºC for 60 minutes. A sample from each batch of colostrum was collected for PCR testing (MAP-positive vs MAP-negative). Newborn heifer calves were removed from the dam within 30-60 minutes of birth and systematically assigned to be fed 3.8 L of either fresh (FR, n = 434) or heat-treated (HT, n = 490) colostrum within 2 hours of birth. After reaching adulthood (> 2 years old), study animals were tested once annually for 3 years (2010, 2011, 2012) for infection with MAP using serum ELISA and fecal culture. Lactation records describing milk production data (kg/cow) and death or culling events were collected during the 3-year testing period. Multivariable logistic and linear regression was used to investigate the effect of feeding HT colostrum on risk for testing positive to MAP during the 3-year testing period (logistic regression) and on first and second lactation milk yield (kg/cow) (linear regression), respectively. Cox proportional hazards regression was used to investigate the effect of feeding HT colostrum on risk and time to removal from the herd. Fifteen percent of all study animals were fed PCR-positive colostrum. By the end of the 3-year testing period, there was no difference in the proportion of animals testing positive for MAP, with either serum ELISA or fecal culture, when comparing the HT group (10.5%) versus the FR group (8.1%; Odds RatioFR = 0.75 (0.46, 1.20)). There was no effect of treatment on first lactation (HT = 11.797 kg; FR = 11,671 kg; P = 0.41) or second lactation (HT = 11,013 kg; FR = 11,235 kg; P = 0.33) milk production. The proportion of cows leaving the herd by the study’s conclusion was not different for animals originally fed HT (68.0%) versus FR (71.7%; Hazard RatioFR = 1.08 (0.92, 1.26)) colostrum. Although feeding HT colostrum (60°C for 60 min) produces short-term benefits including improved passive transfer of IgG and reduced morbidity in the preweaning period, the current study found no benefit of feeding HT colostrum on long-term outcomes including risk for transmission of Mycobacterium avium subsp. paratuberculosis, milk production in the first and second lactation, and longevity within the herd.