Kim Do Hyung, Choi Seong Ho, Park Sung Kwon, Lee Sung Sill, Choi Chang Weon
Department of Animal Science, Gyeongbuk Provincial College, Yecheon 36830, Korea.
Department of Animal Science, Chungbuk National University, Cheongju 28644, Korea.
Asian-Australas J Anim Sci. 2018 Jan;31(1):80-85. doi: 10.5713/ajas.17.0069. Epub 2017 Aug 16.
This study was conducted to investigate the effect of corn grain particle size on ruminant fermentation and blood metabolites in Holstein steers fed total mixed ration (TMR) as a basal diet to explain fundamental data of corn grain for cattle in Korea.
Four ruminally cannulated Holstein steers (body weight 592±29.9 kg) fed TMR as a basal diet were housed individually in an auto temperature and humidity modulated chamber (24°C and 60% for 22 h/d). Treatments in a 4×4 Latin square design were TMR only (control), TMR with whole corn grain (WC), coarsely ground corn grain (CC), and finely ground corn grain (FC), respectively. The corn feeds substituted for 20% energy intake of TMR intake. To measure the ruminal pH, ammonia N, and volatile fatty acids (VFA), ruminal digesta was sampled through ruminal cannula at 1 h intervals after the morning feeding to determine ruminal fermentation characteristics. Blood was sampled via the jugular vein after the ruminal digesta sampling.
There was no difference in dry matter (DM) intake between different corn particle size because the DM intake was restricted to 1.66% of body weight. Different corn particle size did not change mean ammonia N and total VFA concentrations whereas lower (p<0.05) ruminal pH and a ratio of acetate to propionate, and higher (p<0.05) propionate concentration were noted when the steers consumed CC compared with WC and FC. Concentration of blood metabolites were not affected by different particle size of corn grain except for blood triglyceride concentration, which was significantly (p<0.05) increased by FC.
Results indicate that feeding CC may increase feed digestion in the rumen, whereas the FC group seemed to obtain inadequate corn retention time for microbial degradation in the rumen.
本研究旨在调查在以全混合日粮（TMR）为基础日粮的荷斯坦阉牛中，玉米粒粒度对反刍动物发酵和血液代谢物的影响，以解释韩国牛用玉米粒的基础数据。
四头安装了瘤胃瘘管的荷斯坦阉牛（体重592±29.9千克）以TMR为基础日粮，单独饲养在自动温度和湿度调节室（24°C，60%，每天22小时）。采用4×4拉丁方设计，处理分别为仅TMR（对照）、含整粒玉米粒的TMR（WC）、粗磨玉米粒的TMR（CC）和细磨玉米粒的TMR（FC）。玉米饲料替代TMR摄入量的20%能量摄入。为了测量瘤胃液pH值、氨氮和挥发性脂肪酸（VFA），在早晨喂食后每隔1小时通过瘤胃瘘管采集瘤胃消化物样本，以确定瘤胃发酵特性。在采集瘤胃消化物样本后，通过颈静脉采集血液样本。
不同玉米粒粒度之间的干物质（DM）摄入量没有差异，因为DM摄入量被限制在体重的1.66%。不同玉米粒粒度并未改变平均氨氮和总VFA浓度，然而，与WC和FC相比，当阉牛食用CC时，瘤胃液pH值以及乙酸与丙酸的比例较低（p<0.05），丙酸浓度较高（p<0.05）。除血液甘油三酯浓度外，血液代谢物浓度不受不同玉米粒粒度的影响，FC组的血液甘油三酯浓度显著（p<0.05）升高。
结果表明，饲喂CC可能会增加瘤胃中的饲料消化，而FC组在瘤胃中微生物降解的玉米停留时间似乎不足。
