Cow-Calf Production on Tall Fescue-Ladino Clover Pastures with and without Nitrogen Fertilization or Creep Feeding: Spring Calves

Year-long grazing with beef cows and calves on tall fescue-ladino clover pastures was conducted for 4 years to determine if calf production could be economically increased by use of nitrogen fertilizer and/or creep feeding of spring-born calves. Pastures were fertilized with nitrogen at the rates of 0, 112 and 224 kg/ha, and calves received or did not receive creep feed. This study was conducted at the Forage Systems Research Center located in north central Missouri. The first increment of nitrogen (112 kg/ha) increased carrying capacity of the pastures by 3.5 metabolic animal unit months (AUM)/ha over no nitrogen, whereas the second increment (224 kg/ha) increased carrying capacity by an additional 2.5 AUM/ha over the first increment. Pastures with creep feed had .90 AUM/ha greater carrying capacity during the summer phase. On a year-long basis the increase in carrying capacity from creep feed was only .30 AUM/ha. Calves receiving creep feed weighed 32.2 kg more at weaning than those not receiving creep feed. Unadjusted weaning weight declined 9.9 kg with the first increment of nitrogen and declined an additional 10.1 kg with the second increment of nitrogen when calves did not receive creep feed. Unadjusted weaning weight of creep-fed calves was 13.8 kg lower with the first increment of nitrogen and an additional .3 kg lower with the second increment of nitrogen (224 kg vs 112 kg). Average conception rates of cows with calves receiving no creep feed were 80% with no nitrogen, 57% with 112 kg/ha and 28% with 224 kg/ha. For cows with calves receiving creep feed, conception rates were 78% with no nitrogen, 75% with 112 kg/ha and 69% with 224 kg/ha. Weight gains of cows during the breeding season appeared to be unassociated with conception rate. Results for spring-calving cows indicate that, where productive legumes can be maintained in fescue sods, the return from increased carrying capacity by applying nitrogen fertilizer was not sufficient to offset the additional cost because of the decline in calf weaning weights and cow conception rates. Creep feeding appeared to be more practical but would require calf prices above $1.21/kg with 90% calving rate and creep feed at $.ll/kg and with the observed calving rate calf prices above $1.50/kg would be required to be profitable. Copyright © 1979. American Society of Animal Science . Copyright 1979 by American Society of Animal Science.