title: Influence of dietary protein concentrations on performance and nitrogen repletion in stressed calves.
abstract: Three trials were conducted to determine the influence of dietary CP concentration on health and performance of market-transport-stressed feeder calves (Exp. 1 and 2) and on repletion of nutrients lost during a 3-d feed and water deprivation period in steers fed at maintenance energy intake (Exp. 3). In Exp. 1 (84 calves) and 2 (256 calves), feeder calves averaging 184 kg were transported from Tennessee to Texas. In Exp. 1, calves were fed receiving diets containing either 12 or 16% CP. In Exp. 2, calves were fed diets containing 12 or 16% CP and .8 or 1.3% potassium in a 2 x 2 factorial arrangement of treatments. In Exp. 3, four Hereford steers averaging 253 kg were used in an N balance trial. Steers were deprived of feed and water for 3 d and then were limit-fed (1 x maintenance energy requirements) diets calculated to meet 100, 120, 140 or 160% of CP maintenance requirements for 14 d in a 4 x 4 Latin square design. In Exp. 1, calves fed the 16% CP diet had faster (P less than .05) daily gains and higher (P less than .10) feed consumption than calves fed the 12% CP diet during the first 14 d. In Exp. 2, calf performance was not affected by diet CP or K content. Calves fed the 16CP-1.3K diet had lower (P less than .10) mortality than calves on the remaining treatments. In Exp. 3, N balance and serum urea N increased linearly (P less than .05) with increasing dietary CP. Results of these studies are interpreted to indicate that the CP requirement (g/d) of market-transport-stressed feeder calves is similar to requirements of nonstressed calves; however, the CP concentration of the diet of stressed calves may need to be increased when feed intakes are low.
authors: U.S. Department of Agriculture, Bushland, TX 79012.
authors: N A
authors: NA
authors: Cole
authors: D P
authors: DP
authors: Hutcheson
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001806:Blood Urea Nitrogen; D001835:Body Weight; D002417:Cattle; D002418:Cattle Diseases / Q000378:metabolism*; D004044:Dietary Proteins / Q000378:metabolism*; D004435:Eating; D004734:Energy Metabolism; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005508:Food Deprivation / Q000502:physiology; D008297:Male; D009584:Nitrogen / Q000378:metabolism*; D012044:Regression Analysis; D013312:Stress, Physiological / Q000378:metabolism / Q000662:veterinary*; D014186:Transportation; D014868:Water Deprivation / Q000502:physiology
chemical_list: D001786:Blood Glucose; D004044:Dietary Proteins; D005230:Fatty Acids, Nonesterified; D009584:Nitrogen