Performance and forage intake of range cows as affected by mineral supplement and delaying winter supplemental feed

摘要

Polled Hereford cows on native Flint Hills pasture not supplementeduntil February lost more weight from November to February and were in poorercondition during the winter and early spring than cows supplemented beginningin November. But birth weights, weaning weights, conception percentages,and calving intervals were similar for both groups. Balancing for phosphorus,potassium, and copper deficiencies in the forage did not improve cow or calfperformance. Forage intake ranged from 1.70% of fall body weight when dormantwinter grass was low in protein and digestibility to 3.45% when springgrass was higher in protein and more digestible. Forage intake was not influencedby winter supplement program but was slightly higher when mineralswere fed. Although forage consumption increased with cow size, it was notaffected by level of milk production.