By: David L. Cook, Ph.D., Technical Services Manager, Milk Products
Top priority with newborn calves has always been high-quality colostrum to achieve successful transfer of passive immunity. The long-standing definition of successful transfer has been 10 grams of IgG per liter of serum within 24-36 hours after feeding
colostrum. A research study on a large southwest dairy1 demonstrated that 299 of the 300 calves fed a full dose of First Day Formula® CR achieved successful transfer of passive immunity, equivalent to the
other calves in the study that were fed excellent quality maternal colostrum. The efficacy of First Day Formula is obvious – it has been established as an excellent colostrum replacement. However, could there be benefits to using it as a supplement?
Reviewing new research data2 
A recent publication citing transfer of passive immunity data of 2,360 calves from 103 operations2 combined with subsequent morbidity and mortality3 demonstrated that calves achieving higher levels of IgG transfer, exhibited lower mortality and significantly
less episodes of illness.
The publication concluded that there are substantial benefits, especially health related benefits, of achieving higher levels of transfer of passive immunity. This recent research validates 25 grams IgG/liter of serum compared to the previous standard
of 10 IgG/liter. This boost in IgGs has been linked to improved lifetime calf health and is being referred to as the new “excellent” transfer of passive immunity goal. With this information in mind, Select Sires Inc. has established new recommendations for colostrum management.
For dairies raising their own replacement heifers, achieving the newly established “excellent” level of transfer of passive immunity translates to well-documented lifetime benefits, including: 
- reduced treatment and mortality rates,4
- improved growth rates and feed efficiency,5
- decreased age at first calving6
and
- increased first and second lactation milk production.7
Beef on dairy calves can also benefit from excellent transfer of passive immunity, including those being born on the dairy and transported to calf grower facilities. These calves are often faced with considerable challenges early in life such as transportation and comingling. Research8 shows there is significant risk for calves that fail to receive adequate transfer, including:
- 6.4 times greater risk of being sick during the first 28 days of life,
- 3.2 times greater risk of being sick any time prior to weaning,
- 5.4 times greater risk of death prior to weaning,
- sickness during the first 28 days of life that was associated with a 35-pound lower expected weaning weight, and
- greater risk for feedlot respiratory morbidity.
This research indicates that achieving excellent transfer of passive immunity will result in fewer calves getting sick throughout the production cycle. This means that healthy calves entering the feedyard will have better feed conversion and increased
average daily gains compared to those treated for calfhood sickness.
Recommendations for excellent transfer of passive immunity
Calf growers in various parts of the country have found that excellent transfer of passive immunity can be achieved consistently and economically by supplementing maternal colostrum with First Day Formula CR. These calf growers follow specific protocols
of testing maternal colostrum and supplementing.
A controlled research study completed at Penn State University9 with 80 newborn Holstein calves demonstrated that First Day Formula CR, which is manufactured with a whey-based colostrum ingredient, is a viable supplement to be added directly to average IgG level maternal colostrum to achieve excellent transfer of passive immunity. The increase can be attributed to the whey-based colostrum ingredient having a higher concentration of IgG and more soluble than whole colostrum-based ingredients. The combination of whey-based colostrum replacer and maternal colostrum achieved the highest level of IgG absorption in the study.
Select Sires protocol for maternal colostrum supplementation with First Day Formula CR, makes achieving excellent transfer of passive immunity – not only possible, but easy and affordable.
Replace, Supplement or Feed 
Step 1: Test maternal colostrum with a Brix refractometer (*For Jersey calves, deduct 2 from Brix value)
- <20* – Discard or use as transitional milk
- Replace with one full dose (500 grams/150 IgG) of First Day Formula CR or First Day Formula CR Deluxe
- 20-24* – Supplement maternal colostrum with First Day Formula CR
- 50 grams of IgG is equivalent to 166 grams of First Day Formula CR
- 166 grams is equal to one third of a 500 gram packet or one scoop of the provided scoop in the 20 lb. pail
- ≥25* – Feed 3-4 liters
Step 2: Retest the colostrum:
- Use a Brix refractometer to measure the Brix percentage to ensure excellent quality is met
Step 3: Feed the calf
To learn about additional herd management solutions, check out the Build a Better Calf portfolio of products.
REFERENCES: 1Lago, 2019; 2NAMHS Data; 3Lombard, et.al, 2019; 4NAHMS, Wells, 1996; 5Fowler, 1999; Faber et al., 2005; Nocek et al., 1984; Robison et al., 1988; Faber, 2005; 6Faber et al., 2005; 7DeNise, 1989; Faber, 2005; 8Progressive Dairyman 29 June 2018.; 9Lopez et al., 2020