Effects of high ambient temperature and restricted feed intake on urinary and plasma 3-methylhistidine in lactating holstein cows

• Published in: Animal science journal Vol. 77; no. 2; pp. 201 - 207
• Main Authors: Kamiya, M.(National Agricultural Research Center for Kyushu Okinawa Region, Koshi, Kumamoto (Japan)), Kamiya, Y, Tanaka, M, Oki, T, Nishiba, Y, Shioya, S
• Format: Journal Article
• Language: English
• Published: Melbourne, Australia Blackwell Publishing Asia 01-04-2006
• Subjects: 3-methylhistidine; ALIMENTACION RACIONADA; ALIMENTATION RATIONNEE; AZOTE; cow; DAIRY COWS; ESTRES TERMICO; feed restriction; FIBRAS MUSCULARES; FIBRE MUSCULAIRE; HEAT STRESS; high ambient temperature; MUSCLE FIBRES; NITROGEN; NITROGENO; PROTEOLISIS; PROTEOLYSE; PROTEOLYSIS; RESTRICTED FEEDING; STRESS THERMIQUE; UREA; urea nitrogen; UREE; VACAS LECHERAS; VACHE LAITIERE
• ISSN: 1344-3941; 1740-0929
• DOI: 10.1111/j.1740-0929.2006.00338.x

Three experiments were performed to examine the effects of high ambient temperature and feed restrictions on urinary 3-methylhistidine (3MH) excretion and plasma 3MH concentrations as a marker of myofibrillar proteolysis in lactating Holstein cows. In a crossover design, four cows were maintained during two 14-day treatment periods with ad libitum feed intake under constant moderate (18 deg C) or high (28 deg C) ambient temperature (Experiment 1), with ad libitum or 70% ad libitum feed intake under constant moderate temperature (Experiment 2), and with 70% ad libitum feed intake under constant moderate or high ambient temperature (Experiment 3). The total digestible nutrients intake was decreased (P0.01) under high ambient temperature (Experiment 1) or feed restriction (Experiment 2). Across experiments, urinary 3MH excretion during days 10-14 of each treatment period was not different among treatments. However, the plasma 3MH concentrations at day 14 of treatment were increased significantly under high ambient temperature with subsequent reduced feeding (P0.01) or moderate temperature with feed restriction (P0.05), and were increased slightly (P