Graduate students from Washington State University recently evaluated colostrum management on Washington dairy farms to estimate the prevalence of failure of passive transfer.
Serum samples were collected from 952 calves on 56 farms across Washington. The samples were taken from 18 calves aged two to seven days on each farm. Failure of passive transfer was evaluated by serum total protein using a refractometer. Passive transfer was considered failing if serum total protein was less than 5.2 g/dL.
Results show that 34 percent of calves evaluated had failure of passive transfer. This is almost double the 19 percent reported for the U.S. Twenty-percent of herds had less than 20 percent of calves with failure of passive transfer, while 44 percent of herds had greater than 30 percent of calves with failure of passive transfer.
Researchers found several management factors that increased the risk of passive transfer failure.
- The odds of having failure of passive transfer were 3.7 times greater if a milker was responsible for collecting colostrum versus other personnel, suggesting that milkers may be too busy to collect quality colostrum.
- The likelihood of having failure of passive transfer was 2.3 times greater if colostrum quality was not evaluated versus evaluated by a colostrometer, suggesting that using a colostrometer to eliminate first feedings of poor quality colostrum may help reduce failure of passive transfer.
- Risk was 8.9 times greater if a colostrum supplement was added to maternal colostrum. This suggests adulteration of maternal colostrum with supplements may increase failure of passive transfer on a farm. Alternatively, herds that feel it necessary to add supplements to colostrum may have other factors contributing to poor quality colostrum and thus failure of passive transfer.
Reduce the risk of failure of passive transfer by designating personnel for colostrum harvest and feeding, evaluating colostrum quality and question the need for colostrum supplements.