Kim Tae-Bin, Lee Jae-Sung, Cho Seung-Yeol, Lee Hong-Gu
Department of Animal Science and Technology, Konkuk University, Seoul 05029, Korea.
Institute of Research, Eugene Bio Ltd., Woncheon-dong, Suwon 16675, Korea.
Animals (Basel). 2020 Sep 11;10(9):1631. doi: 10.3390/ani10091631.
The aim of the present study was to evaluate the effects of adding dietary rumen-protected microencapsulated supplements into the ruminal fluid on the milk fat compositions of dairy cows. These supplements comprised linseed oil, vitamin E, rosemary extract, and hydrogenated palm oil (MO; Microtinic Omega, Vetagro S.p.A, Reggio Emilia, Italy). For in vitro ruminal fermentation, Holstein-Friesian dairy cows each equipped with a rumen cannula were used to collect ruminal fluid. Different amounts (0%, 1%, 2%, 3%, 4%, and 5%) of MO were added to the diets to collect ruminal fluids. For the in vivo study, 36 Holstein-Friesian dairy cows grouped by milk yield (32.1 ± 6.05 kg/d/head), days in milk (124 ± 84 d), and parity (2 ± 1.35) were randomly and evenly assigned to 0.7% linseed oil (LO; as dry matter (DM) basis) and 2% MO (as DM basis) groups. These two groups were fed only a basal diet (total mixed ration (TMR), silage, and concentrate for 4 weeks) (period 1). They were then fed with the basal diet supplemented with oil (0.7 LO and 2% MO of DM) for 4 weeks (period 2). In the in vitro experiment, the total gas production was found to be numerically decreased in the group supplemented with 3% MO at 48 h post in vitro fermentation. A reduction of total gas production (at 48 h) and increase in ammonia concentration (24 h) were also observed in the group supplemented with 4% to 5% MO ( < 0.05). There were no differences in the in vitro fermentation results, including pH, volatile fatty acids, or CH among groups supplemented with 0%, 1%, and 2% MO. The results of the in vitro study suggest that 2% MO is an optimal dosage of MO supplementation in cows' diets. In the in vivo experiment, the MO supplement more significantly ( < 0.01) increased the yield of total w3 fatty acids than LO (9.24 vs. 17.77 mg/100 g milk). As a result, the ratio of total omega-6 to omega-3 fatty acids was decreased ( < 0.001) in the MO group compared to that in the LO group (6.99 vs. 3.48). However, the milk yield and other milk compositions, except for milk urea nitrogen, were similar between the two groups ( > 0.05). Collectively, these results suggest that the dietary supplementation of 2% MO is beneficial for increasing omega-3 fatty acids without any negative effects on the milk yield of dairy cows.
本研究的目的是评估在瘤胃液中添加日粮瘤胃保护微胶囊补充剂对奶牛乳脂肪成分的影响。这些补充剂包括亚麻籽油、维生素E、迷迭香提取物和氢化棕榈油(MO;Microtinic Omega,Vetagro S.p.A,意大利雷焦艾米利亚)。对于体外瘤胃发酵,使用每头都装有瘤胃瘘管的荷斯坦-弗里生奶牛来收集瘤胃液。向日粮中添加不同量(0%、1%、2%、3%、4%和5%)的MO以收集瘤胃液。对于体内研究,将36头按产奶量(32.1±6.05千克/天/头)、泌乳天数(124±84天)和胎次(2±1.35)分组的荷斯坦-弗里生奶牛随机且均匀地分配到0.7%亚麻籽油(LO;以干物质(DM)计)和2% MO(以DM计)组。这两组仅饲喂基础日粮(全混合日粮(TMR)、青贮饲料和精饲料,为期4周)(第1阶段)。然后给它们饲喂添加了油(0.7% LO和2% MO的DM)的基础日粮,为期4周(第2阶段)。在体外实验中,发现在体外发酵48小时后,添加3% MO的组总产气量在数值上有所下降。在添加4%至5% MO的组中也观察到总产气量(48小时时)降低和氨浓度升高(24小时时)(P<0.05)。在添加0%、1%和2% MO的组之间,体外发酵结果,包括pH值、挥发性脂肪酸或甲烷,没有差异。体外研究结果表明,2% MO是奶牛日粮中MO补充的最佳剂量。在体内实验中,MO补充剂比LO更显著地(P<0.01)提高了总w3脂肪酸的产量(9.24对17.77毫克/100克牛奶)。结果,与LO组相比,MO组中总ω-6与ω-3脂肪酸的比例降低(P<0.001)(6.99对3.48)。然而,两组之间的产奶量和其他乳成分,除了乳尿素氮,相似(P>0.05)。总体而言,这些结果表明,日粮中添加2% MO有利于增加ω-3脂肪酸,而对奶牛的产奶量没有任何负面影响。