Ku Min-Jung, Miguel Michelle A, Kim Seon-Ho, Jeong Chang-Dae, Ramos Sonny C, Son A-Rang, Cho Yong-Il, Lee Sung-Sill, Lee Sang-Suk
Livestock Research Institute, Jeonnam Agricultural Research and Extension Services, Gangjin 59213, Korea.
Department of Animal Science and Technology, Sunchon National University, Suncheon 57922, Korea.
J Anim Sci Technol. 2023 Sep;65(5):951-970. doi: 10.5187/jast.2023.e16. Epub 2023 Sep 30.
This study utilized Italian ryegrass silage (IRGS) - based total mixed ration (TMR) as feedstuff and evaluated its effects on rumen fermentation, growth performance, blood parameters, and bacterial community in growing Hanwoo heifers. Twenty-seven Hanwoo heifers (body weight [BW], 225.11 ± 10.57 kg) were randomly allocated to three experimental diets. Heifers were fed 1 of 3 treatments as follows: TMR with oat, timothy, and alfalfa hay (CON), TMR with 19% of IRGS (L-IRGS), and TMR with 36% of IRGS (H-IRGS). Feeding high levels of IRGS (H-IRGS) and CON TMR to heifers resulted in a greater molar proportion of propionate in the rumen. The impact of different TMR diets on the BW, average daily gain, dry matter intake, and feed conversion ratio of Hanwoo heifers during the growing period did not differ ( > 0.05). Furthermore, the blood metabolites, total protein, albumin, aspartate aminotransferase, glucose, and total cholesterol of the heifers were not affected by the different TMR diets ( > 0.05). In terms of rumen bacterial community composition, 264 operational taxonomic units (OTUs) were observed across the three TMR diets with 240, 239, and 220 OTUs in CON, L-IRGS, and H-IRGS, respectively. IRGS-based diets increased the relative abundances of genera belonging to phylum but decreased the abundances of genus belonging to phylum compared with the control. Data showed that was the most dominant phylum, while was the dominant species across the three TMR groups. The relative abundance of in the rumen increased in heifers fed with high inclusion of IRGS in the TMR (H-IRGS TMR). The relative abundance of in the rumen significantly increased when heifers were fed H-IRGS TMR while increased in both L-IRGS and H-IRGS TMR groups. Results from the current study demonstrate that the inclusion of IRGS in the TMR is comparable with the TMR containing high-quality forage (CON). Thus, a high level of IRGS can be used as a replacement forage ingredient in TMR feeding and had a beneficial effect of possibly modulating the rumen bacterial community toward mainly propionate-producing microorganisms.
本研究采用以意大利黑麦草青贮饲料（IRGS）为基础的全混合日粮（TMR）作为饲料，并评估其对生长中的韩牛小母牛瘤胃发酵、生长性能、血液参数和细菌群落的影响。将27头韩牛小母牛（体重[BW]，225.11±10.57千克）随机分配到三种试验日粮中。小母牛按以下3种处理方式之一进行饲喂：含燕麦、梯牧草和苜蓿干草的TMR（CON）、含19% IRGS的TMR（L-IRGS）和含36% IRGS的TMR（H-IRGS）。给小母牛饲喂高比例IRGS（H-IRGS）和CON TMR导致瘤胃中丙酸的摩尔比例更高。不同TMR日粮对生长阶段韩牛小母牛的体重、平均日增重、干物质摄入量和饲料转化率的影响没有差异（P>0.05）。此外，不同TMR日粮对小母牛的血液代谢物、总蛋白、白蛋白、天冬氨酸转氨酶、葡萄糖和总胆固醇没有影响（P>0.05）。在瘤胃细菌群落组成方面，在三种TMR日粮中观察到264个可操作分类单元（OTU），CON、L-IRGS和H-IRGS中分别有240、239和220个OTU。与对照相比，以IRGS为基础的日粮增加了属于门 的属的相对丰度，但降低了属于门 的属的丰度。数据显示， 是最主要的门，而 在三个TMR组中都是优势种。在TMR中高比例添加IRGS（H-IRGS TMR）的小母牛瘤胃中 的相对丰度增加。当给小母牛饲喂H-IRGS TMR时，瘤胃中 的相对丰度显著增加，而 在L-IRGS和H-IRGS TMR组中均增加。本研究结果表明，在TMR中添加IRGS与含优质饲草的TMR（CON）相当。因此，高比例的IRGS可用作TMR饲喂中的替代饲草成分，并具有可能将瘤胃细菌群落调节为主要产生丙酸的微生物的有益效果。
