title: Relationship of lactose to nitrogen metabolism of artificially reared beef calves.
abstract: The purpose was to study the relationship of lactose to nitrogen metabolism of artificially-reared beef calves. Calves from 35 market heifers were fed whole milk at 12% of body weight daily to 14 days and then at 8% of body weight to 28 days. An 18.3% crude protein dry diet was fed for ad libitum consumption on days 1 to 28. For days 29 to 84, nine calves were assigned to each of three treatments: A) 60:40 grain:hay dry diet, B) 60:40 grain diet with liquid lactose fed separately, and C) 60:40 dry diet containing dried lactose. During days 1 to 28, body weights were not reduced. Calves compensated for reduction of whole milk intake by increasing their intakes of dry diet. gamma-Glutamyl transferase and urea nitrogen in blood serum were reduced when milk intake was decreased. Beef calves can be adapted to early weaning and artificial rearing if started soon after birth. Lactose treatments decreased dry matter intakes and vitamin E in blood, but body weights were not different. Feed conversion was improved; nitrogen balance and urinary nitrogen excretion were decreased by liquid lactose. Urea nitrogen in blood was related to nitrogen balance. Liquid lactose increased serum alkaline phosphatase and serum glucose. The role of liquid lactose was to supply adequate energy for improved utilization of retained nitrogen.
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001806:Blood Urea Nitrogen; D001835:Body Weight; D002417:Cattle / Q000097:blood / Q000378:metabolism*; D004032:Diet; D005260:Female; D007785:Lactose / Q000378:metabolism*; D008297:Male; D009584:Nitrogen / Q000378:metabolism*; D014886:Weaning; D005723:gamma-Glutamyltransferase / Q000097:blood
chemical_list: D005723:gamma-Glutamyltransferase; D007785:Lactose; D009584:Nitrogen