مقایسه تأثیر افزایش پروتئین جیره با کنجاله سویا یا پودر گوشت بر عملکرد، متابولیت‌های خون، انسولین و آنزیم های کبدی در گوساله های نر هلشتاین

The current study was evaluated the increased dietary protein level supplied either by soybean meal or meat meal sources (SBM vs. MM) in growing Holstein male calves on performance, blood metabolites, liver enzymes and insulin. 36 growing Holstein male calves averaging 167.7 kg body weight were allocated in a competently randomized design (12 animals/each) in 3 treatments; 1) basal protein level (crude protein=13.8%; CON), 2) SBM source (14.9%), 3) MM source (14.9%). The study lasted 9 weeks. The results show that intake and gain of calves did not differ among treatments. Regardless of protein sources, elevated crude protein level caused to slight increase in feed efficiency (P=0.09). Among the blood metabolites only glucose was tended to be increased (P=0.07). Liver enzyme concentrations (alanine aminotransferase and aspartate aminotransferase) were not differed among treatments; however blood insulin concentration was greatest in MM treatment (P=0.04). In conclusion despite greater CP level supplied with SBM is not recommendable but improved glucose concentration and increased insulin concentration with MM may affect growth rate of growing calves.