While colostrum feeding and management has vastly improved over the past three decades, there is still room for improvement to reduce calf death losses and incidence rates of scours and respiratory disease.
“The previous standard of 10g/L for serum IgG has served its purpose in challenging producers to improve their colostrum management practices,” says Jason Lombard, a veterinarian with USDA’s Animal and Plant Health Inspection Service. “With almost 90 percent of calves currently meeting these standards, it is time to once again challenge producers to continue making improvements.”
Lombard spoke at the virtual Dairy Calf and Heifer Association annual conference this spring. Lombard notes that mortality rates for preweaning dairy heifer calves have dropped from 10.8 percent of calves in 1996 to 6.4% in 2014. “However, preweaning calf morbidity, primarily scours and respiratory disease, remained at nearly 30%,” he says. Those illness, especially bovine respiratory disease, can have long-term impacts on performance and raising costs.
To achieve better transfer of passive immunity (TPI), a group of U.S. and Canadian calf specialists met in 2018 to discuss and propose new passive immunity standards. Rather than simply having a dichotomous, good/bad standard, their new standard has four categories so farmers can see where their farms rank in achieving excellent TPI.
“The construction of the four levels was based on evaluation of calf morbidity and mortality in the National Animal Health Management Study calf component (2014) as well as other published literature,” says Lombard. See table.
TPI Serum IgG Equivalent Equivalent Farm Level NAHMS
Category categories TP (g/dL) Brix % % calves Study 2014
(g/L) % calves
Excellent >25.0 >6.2 >9.4% >40% 35.5%
Good 18-24.9 5.8-6.1 8.9-9.3% ~30% 25.7%
Fair 10-17.9 5.1-5.7 8.1-8.8 ~20% 26.8%
“The consensus recommendations are achievable by commercial dairy operations with good colostrum management programs,” he says.
There are two approaches farmers can use:
- A single feeding of colostrum at approximately 2 hours after birth, delivering approximately 300 grams of IgG, or
- Feeding multiple colostrum feedings and delivering approximately 400 grams of total IgG in the first 24 hours.
“One of the consistent findings from multiple studies has show that feeding high-quality colostrum within two to four hours after birth will achieve excellent TPI,” says Lombard. “Although many farms will choose to provide a single feeding of colostrum and the consensus standard can be achieved, there are benefits to multiple colostrum feedings.”
Feeding transition milk after colostrum also has benefits. And heat treating colostrum (140°F for 30 minutes) will reduce bacterial concentrations while maintaining adequate IgG concentrations.