The $150,000 grant was part of a series announced by the US Department of Agriculture’s National Institute of Food and Agriculture.
The project seeks to “promote economically, socially, and environmentally sustainable agriculture and resilient communities,” according to the grant proposal. “Specifically, this proposal focuses on improving the efficiency of nutrient utilization and optimizing metabolism of calves.”
The research project evaluates the use of supplemental amounts of the amino acid leucine in the diets of neonatal dairy calves and what it means for calf muscle development, said Kendall Swanson, professor in the department of animal sciences at North Dakota State University.
“It could potentially offer different formulations for milk replacer that could increase growth of milk fed calves, [and mean] larger weaning weights,” he told FeedNavigator. “Depending on when you would market the animals if they are male calves, it’s more pounds of product, and for females it might enhance development and when they reach puberty and lifetime productivity – but those are things we can examine in the future.”
The two-year study was awarded through the USDA and the intention is to have primarily results in the next year with publications coming later, he said.
The project’s aim is to determine the influence of increasing amounts of supplemental leucine nitrogen balance, metabolite and hormone profiles, pancreatic histomorphology of insulin containing-clusters and the expression of proteins that control protein synthesis and degrade muscle, liver, intestine and the pancreas, he said in the proposal.
Grant details and project design
There has been research done previously on leucine supplementation in neonatal animals, especially swine, said Swanson. In that work, it was established that the amino acid played a role at the cellular level on protein synthesis in the cell.
“Some research in pigs [suggested] that if you increase leucine to neonatal or preterm pigs it can enhanced muscle development,” he said. “If we can increase the lean muscle growth it can have effects into adulthood.”
The project hypothesizes that adding supplemental leucine to the milk replacer offered neonatal calves will improve nitrogen balance, lean tissue growth and boost metabolic signaling, Swanson said in the grant proposal.
Currently, the first set of calves are being raised on diets with differing amounts of leucine in their milk replacer, he added. Calves receive the trial diet for a month.
The trial diets include a control and 0.4, 0.6, or 0.8 g per kg body weight of additional leucine, he said in the grant proposal. Body weights will be measured on days 1, 18, 22 and 28, nutrient balance will be established on days 22 though 28 and blood samples will be collected.
Samples of liver, pancreas, jejunum and muscle also will be gathered and analyzed following the feeding trial, he said in the proposal.
A nitrogen balance test also will be completed during the feeding trial, said Swanson.
“We’re starting to collect data and samples and this will go on through the fall until we get our group of 24 animals,” he said. “Then we’ll focus on data analysis and sample analysis.”
What’s next?
A future step for the project is to evaluate the influence of supplemental leucine into adulthood for the animal, said Swanson.
Initial work is being done with dairy calves, as they are more likely to be on milk replacer, he said. However, it also could potentially be applied to orphan calves or feedlot animals.
There is the potential that findings would be transferable to other species, especially other ruminant species, Swanson said.
One goal of the project will be to develop additional approaches to improve early growth and metabolism development for dairy or beef calves, according to the grant proposal.