WASHINGTON, May 27 (UPI) — U.S. scientists say they’ve created a model for manipulating vitamin D levels in calves to determine how much is needed for optimal growth and health.
The U.S. Department of Agriculture researchers noted newborn dairy calves get crucial vitamin D from their mothers as they nurse during the first few days after birth. Later, the calf often receives vitamin D in commercial milk replacements. But, the scientists said, levels of vitamin D in the supplements may need to be reevaluated, given recent evidence suggesting vitamin D status influences not only bone growth, but also immune function.
Agricultural Research Service microbiologist Brian Nonnecke and colleagues Tim Reinhardt and Ray Waters said they examined the effects of vitamin D on the calf’s immune system — especially relevant given the animal’s susceptibility to infectious respiratory and intestinal diseases during its first weeks of life.
In the study, vitamin D status was controlled by vitamin D injections given to calves fed a vitamin-D-free milk replacement.
The researchers also found the model could be adapted to examine effects of subclinical vitamin D deficiency on the immune system of the calf. That, they said, is important, given up to 10 percent of neonatal U.S. dairy calves die during the first months of life, and more than 30 percent are diagnosed with some form of clinical disease.
The study is reported in the Journal of Dairy Science.
Copyright 2010 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI’s prior written consent.