The results of a research, funded by the farmer-driven Northern New York Agricultural Development Program, evaluating a nutritional strategy to help dairy calves beat heat stress conditions unique to the northern region of New York State will be presented at the American Dairy Science Association meeting in Pittsburgh, PA, June 25-28, 2017.
Heat and humidity are the two key factors that prompted development of a project evaluating fat supplementation as a way to optimize dairy calf caloric intake to improve growth and health during times of heat stress. The research trial was conducted by W. H. Miner Agricultural Research Institute, Chazy, Clinton County, NY.
“Heat stress accounts for approximately $253,000 in annual losses of dairy animals from birth to one year of age across New York state,” said Miner Institute Director of Research Katie Ballard, adding, “and the average maximum temperature-to-humidity index (THI) in northern New York has been greater than the upper critical limit for lactating dairy cows from May through September in recent years.”
“When nutritional intake is reduced and energy is spent moderating body temperature during heat stress, calf growth is decreased and immune response can be negatively impacted. In addition to temperatures above the critical high index, the wide swings in temperatures in Northern New York are potentially more of a detriment because animals, young and mature, do not have time to properly acclimatize,” said project leader Kayla Hultquist, who will present the project results to the American Dairy Science Association.
In previous research, dairy calves consumed more starter grain to support the additional energy needed to regulate their body temperature in cold weather.
The research trials at Miner Institute focused on calves from 2 days to 57 days old. Each calf was assigned to one of three milk replacer treatments: no added fat, fat added when temperature exceeded 78 degrees Fahrenheit, or fat added throughout the study.
Average daily weight gains during the first six weeks of age were greater for calves receiving fat supplementation compared to the group not receiving fat-supplemented milk replacer at the same age, however, there was no difference between treatments when calf height or stature was compared. This indicates that weight gained by fat-supplemented calves was not because they grew taller; they just got heavier which is not desirable.
Overall feed efficiency, measured as weight gain across the entire trial period, was the greatest in the group that received milk replacer without added fat, indicating that farmers should considering feeding a lower fat milk replacer in the summer months to increase feed efficiency and still achieve appropriate growth in their calves.
The farmer-driven Northern New York Agricultural Development Program is a research and technical assistance program serving all agricultural sectors in Clinton, Essex, Franklin, Jefferson, Lewis, and St. Lawrence counties. Funding for the Northern New York Agricultural Development Program is supported by the New York State Senate and administered through the New York State Department of Agriculture and Markets.