Animal Science, Department of


Date of this Version



2019 Nebraska Beef Cattle Report


Copyright © The Board Regents of the University of Nebraska.


A modeling study evaluated the effects of milk production level on nutrient balance in March-and May-calving cows grazing Sandhills upland range during the breeding season. Forage quality of upland range peaks in June and steadily declines in July until November. In March-calving cows, metabolizable protein (MP) and energy were deficient by July 1 in all milking potential cows, which is exacerbated in greater milking potential cows. May-calving cows with 20 to 30 lbs of milk are predicted to enter the breeding season with a deficiency in MP and energy. In an effort to match cow type to environment in the Sandhills, producers should be selecting against high milk potential. With timing of forage quality decline and the start of breeding season in July, selecting for moderation in milk production becomes even more important in May-calving herds. Supplementation to meet MP deficiency with high ruminally undegradable protein supplements may be need in later breeding cows and younger cows in both March-and May-herds.