The premise is simple: raise quality replacement heifers as economically as possible.
One way to accomplish this goal is by following limit-feeding practices. This strategy has the potential to decrease feed use, increase feed efficiency and decrease manure excretion by dairy heifers, all positive factors for your heifer-rearing program. But, does a feeding program like this have any nagging, and potentially negative, carryover effects during lactation?
Researchers at the University of Wisconsin and the U.S. Dairy Forage Research Center recently conducted a study to find the answer. The results were published in the November Journal of Dairy Science.
They followed 96 pregnant Holstein heifers that were fed either one of two limit-fed diets or a control diet for 180 days. One limit-fed diet was offered at 85 percent of the control diet without an ionophore. The second limit-fed diet was offered at 80 percent of the control diet with an ionophore.
Results show that limit-fed heifers consumed less dry matter and neutral detergent fiber, and had greater respective average daily gains and improved feed efficiency than heifers fed the control diet. Furthermore, no differences in rumen pH or volatile fatty acids were observed. And, rumen digestion volume, density and weight were not affected by limit feeding.
At calving, no differences were observed for dystocia index or calf body weight. Also, there were no differences in cow body weight seven days after calving between the treatments.
Lactation body weight, dry matter intake and cow feed efficiency did not differ between the treatments at 45 or 90 days in milk, either. Nor was there any difference in milk yield and milk components.
Therefore, the researchers concluded that limit-feeding pregnant heifers did not result in any carryover effects during the first lactation for rumen digestion volume, dry matter intake or milk yield.