The current paradigm of feeding an adequate amount of colostrum to calves within a few hours of life has been to achieve the passive transfer of immunity. In addition to the immunoglobulins, colostrum has been found to contain high concentrations of non-nutritive bioactive factors that may contribute to the development of the gastrointestinal tract, thus leading to healthier calves. Although the roles of these bioactive factors are not fully understood, it is worthwhile to examine the phenotypical manifestations of these bioactive factors on the development of calves. The main objective of this project is to explore the effects of feeding neonatal calves colostrum as the first two feedings on their average daily gain (ADG) and health status during the pre-weaning period as compared to those that receive the conventional one feeding. A higher ADG might suggest efficient
feed conversion, healthier calves with less neonatal problems, and may eventually lead to improved productivity in the herd.

Our study will be conducted on one commercial dairy farm that has a long-standing working relationship with the Cornell Ambulatory Clinic. Heifer calves (n=180) will be randomly enrolled to either the treatment group or the control group. All the heifer calves will be weighed at birth and will get their first feeding of colostrum 4 L within 2 hours of birth via an esophageal tube. Then 12-16 hours later, the treatment group calves will receive a second dose of colostrum 3 L via an esophageal tube, whereas the control group will receive 3 L acidified pasteurized milk. Then, all calves will be fed acidified pasteurized milk following farm protocols. The weights of all calves will be monitored weekly until weaning at 6 weeks. The weekly ADG and the ADG over the pre-weaning period for the control and treatment groups will be compared. Farm personnel will be blinded to the treatments. Farm personnel will be trained to diagnose and treat neonatal diseases, with a focus on calf scours and pneumonia. Any diagnosis and treatments will be recorded in DairyComp 305 and documented at the calf barns.

We hypothesize that heifer calves receiving two initial feedings of colostrum will have a higher ADG during the pre-weaning period and will be less at risk for neonatal diseases; or if diagnosed, will require fewer treatments than those calves that received one feeding of colostrum. Subsequently, the results of the study will allow us to improve calf management and welfare, reduce the use of antibiotics, and increase economic efficiency in the dairy industry.