Submitted to: Journal of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: December 15, 2002
Publication Date: January 31, 2003
Citation: PHILLIPS, W.A., COLEMAN, S.W., RILEY, D.G., CHASE, C.C., MAYEUX JR, H.S. PERFORMANCE OF ROMOSINUANO STEER CALVES AS WINTER STOCKER CALVES FOR THE SOUTHERN GREAT PLAINS. JOURNAL OF ANIMAL SCIENCE. 2003. p. 21. Interpretive Summary: Abstract Only.
Technical Abstract: Beef calves must be genetically equipped to withstand the climatic conditions of the coastal region of the Southern U.S. to be productive there. However, after weaning they may be transported to more temperate regions for growth and finishing. The objective of this experiment was to determine the performance of a new tropical breed reared in a tropical environment but grown in a temperate environment. In the fall of 2001 approximately 21 d after weaning, Romosinuano (N = 36) and Angus (N = 18) steers born and reared at Brooksville, FL were transported 2025 km to El Reno, OK. Twenty eight days after arrival, calves were blocked by breed and randomly assigned to graze one of three winter wheat pastures. One third of the Angus and one third of the Romosinuano calves within each pasture were weighed after 10, 20 or 30 d of grazing to determine the rate of gain at 10-d intervals when exposed to winter wheat pasture for the first time. All weights were taken at approximately 1000 without fasting. Initial BW at the beginning of the 30-d grazing period was similar (P = 0.65) between the two breeds (Angus = 212 kg and Romosinuano = 208 kg). Angus calves tended (P = 0.15) to gain weight more rapidly than Romosinuano calves, but the impact of the sudden shift to a diet of winter wheat forage was similar between the two breeds. During the first 10 d of grazing, calves lost 7.4 kg. By day 20, the calves had recovered most the weight lost and had BW similar to day 0. After 30 d of grazing of winter wheat pasture, Angus calves had gained 10.5 kg and Romosinuano calves had gained 5.2 kg. Romosinuano calves gained weight at a slower rate than Angus calves born and reared in a subtropic environment, but the capacity to adapt to the unique chemical and physical characteristics of winter wheat pasture was similar between Angus and Romosinuano calves.