Abstract
ABSTRACTThree experiments were performed to examine the effects of high ambient temperature and feed restriction on nitrogen (N) utilization in lactating cows. Experiment 1 investigated N utilization in four cows fed ad libitum in a 2 × 2 crossover design under constant moderate (18°C) or high (28°C) ambient temperatures. The milk N secretion (P < 0.01) and protein concentration (P < 0.05) decreased under high ambient temperature. Experiment 2 investigated N utilization in four cows under constant moderate ambient temperature in a 2 × 2 crossover design with ad libitum or 70% ad libitum feed intake. The milk N secretion and protein concentration both decreased with feed restriction (P < 0.05). Experiment 3 investigated N utilization in four cows fed 70% ad libitum in a 2 × 2 crossover design under constant moderate or high ambient temperatures. The milk protein concentration decreased under high ambient temperature (P < 0.01). The milk N secretion tended to decrease under high ambient temperature (P < 0.10). Therefore, decreased N utilization for milk production at high ambient temperature is mainly caused by a reduced feed intake and the high ambient temperature itself.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
