Kang Hyeok Joong, Piao Min Yu, Park Seung Ju, Na Sang Weon, Kim Hyun Jin, Baik Myunggi
Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea.
Institute of Green Bio Science and Technology, Seoul National University, Pyeongchang 25354, Korea.
Asian-Australas J Anim Sci. 2019 May;32(5):657-664. doi: 10.5713/ajas.18.0621. Epub 2018 Nov 27.
This study was performed to evaluate whether cold ambient temperature and dietary rumen-protected fat (RPF) supplementation affect growth performance, rumen fermentation, and blood parameters in Korean cattle steers.
Twenty Korean cattle steers (body weight [BW], 550.6±9.14 kg; age, 19.7±0.13 months) were divided into a conventional control diet group (n = 10) and a 0.5% RPF supplementation group (n = 10). Steers were fed a concentrate diet (1.6% BW) and a rice straw diet (1 kg/d) for 16 weeks (January 9 to February 5 [P1], February 6 to March 5 [P2], March 6 to April 3 [P3], and April 4 to May 2 [P4]).
The mean and minimum indoor ambient temperatures in P1 (-3.44°C, -9.40°C) were lower (p<0.001) than those in P3 (5.87°C, -1.86°C) and P4 (11.18°C, 4.28°C). The minimum temperature in P1 fell within the moderate cold-stress (CS) category, as previously reported for dairy cattle, and the minimum temperatures of P2 and P3 were within the mild CS category. Neither month nor RPF supplementation affected the average daily gain or gain-to-feed ratio (p>0.05). Ruminal ammonia nitrogen concentrations were higher (p<0.05) in cold winter than spring. Plasma cortisol concentrations were lower (p<0.05) in the coldest month than in the other months. Serum glucose concentrations were generally higher in colder months than in the other months but were unaffected by RPF supplementation. RPF supplementation increased both total cholesterol (p = 0.004) and high-density lipoprotein (HDL) concentrations (p = 0.03).
Korean cattle may not be significantly affected by moderate CS, considering that the growth performance of cattle remained unchanged, although variations in blood parameters were observed among the studied months. RPF supplementation altered cholesterol and HDL concentrations but did not affect growth performance.
本研究旨在评估寒冷环境温度和日粮中添加瘤胃保护脂肪（RPF）是否会影响韩牛阉牛的生长性能、瘤胃发酵和血液参数。
将20头韩牛阉牛（体重[BW]，550.6±9.14千克；年龄，19.7±0.13个月）分为常规对照日粮组（n = 10）和0.5% RPF添加组（n = 10）。阉牛饲喂精料日粮（体重的1.6%）和稻草日粮（1千克/天），持续16周（1月9日至2月5日[P1]，2月6日至3月5日[P2]，3月6日至4月3日[P3]，4月4日至5月2日[P4]）。
P1期的室内平均和最低环境温度（-3.44°C，-9.40°C）低于（p<0.001）P3期（5.87°C，-1.86°C）和P4期（11.18°C，4.28°C）。如先前对奶牛报道的那样，P1期的最低温度属于中度冷应激（CS）类别，P2期和P3期的最低温度属于轻度CS类别。月份和RPF添加均未影响平均日增重或增重与饲料比（p>0.05）。冬季寒冷时瘤胃氨氮浓度高于春季（p<0.05）。最冷月份的血浆皮质醇浓度低于其他月份（p<0.05）。较冷月份的血清葡萄糖浓度通常高于其他月份，但不受RPF添加的影响。添加RPF增加了总胆固醇（p = 0.004）和高密度脂蛋白（HDL）浓度（p = 0.03）。
考虑到尽管在研究月份之间观察到血液参数存在差异，但阉牛的生长性能保持不变，韩牛可能不会受到中度冷应激的显著影响。添加RPF改变了胆固醇和HDL浓度，但不影响生长性能。
