Huyen Nguyen Thi, Verstegen Martin W A, Hendriks Wouter H, Pellikaan Wilbert F
Animal Nutrition Group, Wageningen University, PO Box 338, Wageningen, 6700 AH, the Netherlands.
Department of Farm Animal Health, Utrecht University, PO Box 80.163, Utrecht, 3508 TD, the Netherlands.
Anim Nutr. 2020 Sep;6(3):333-341. doi: 10.1016/j.aninu.2020.05.001. Epub 2020 Jun 25.
The effects of replacing grass silage by sainfoin silage in a total mixed ration (TMR) based diet on fatty acid (FA) reticular inflow and milk FA profile of dairy cows was investigated. The experiment followed a crossover design with 2 dietary treatments. The control diet consisted of grass silage, corn silage, concentrate and linseed. In the sainfoin diet, half of the grass silage was replaced by a sainfoin silage. Six rumen cannulated lactating multiparous dairy cows with a metabolic body weight of 132.5 ± 3.6 kg BW, 214 ± 72 d in milk and an average milk production of 23.1 ± 2.8 kg/d were used in the experiment. Cows were paired based on parity and milk production. Within pairs, cows were randomly assigned to either the control diet or the sainfoin diet for 2 experimental periods (29 d per period). In each period, the first 21 d, cows were housed individually in tie-stalls for adaptation, then next 4 d cows were housed individually in climate-controlled respiration chambers to measure CH. During the last 4 d, cows were housed individually in tie stalls to measure milk FA profile and determine FA reticular inflow using the reticular sampling technique with Cr-ethylenediaminetetraacetic acid disodium salt dihydrate (EDTA) and Yb-acetate used as digesta flow markers. Although the dietary C18:3n-3 intake was lower ( = 0.025) in the sainfoin diet group, the mono-unsaturated FA reticular inflow was greater ( = 0.042) in cows fed the sainfoin diet. The reticular inflow of trans-9, trans-12-C18:2 and cis-12, trans-10 C18:2 was greater ( ≤ 0.024) in the sainfoin diet group. The cows fed sainfoin diet had a lower ( ≤ 0.038) apparent ruminal biohydrogenation of cis-9-C18:1 and C18:3n-3, compared to the cows fed the control diet. The sainfoin diet group had greater ( ≤ 0.018) C18:3n-3 and cis-9, cis-12-C18:2 proportions in the milk FA profile compared to the control diet group. Transfer efficiencies from feed to milk of C18:2, C18:3n-3 and unsaturated FA were greater ( ≤ 0.0179) for the sainfoin diet. Based on the results, it could be concluded that replacing grass silage by sainfoin silage in dairy cow rations reduces ruminal C18:3n-3 biohydrogenation and improves milk FA profile.
研究了在全混合日粮（TMR）基础日粮中用红豆草青贮替代禾本科青贮对奶牛脂肪酸（FA）瘤网流入量和乳脂肪酸谱的影响。试验采用交叉设计，有2种日粮处理。对照日粮由禾本科青贮、玉米青贮、精料和亚麻籽组成。在红豆草日粮中，一半的禾本科青贮被红豆草青贮替代。选用6头带瘤胃瘘管的经产泌乳奶牛，代谢体重为132.5±3.6 kg体重，泌乳214±72 d，平均产奶量为23.1±2.8 kg/d用于试验。奶牛按胎次和产奶量配对。在每对中，奶牛被随机分配到对照日粮或红豆草日粮，进行2个试验期（每期29 d）。在每个时期，前21 d，奶牛单独饲养在拴系牛栏中适应，然后接下来4 d，奶牛单独饲养在气候控制的呼吸室内以测量CH。在最后4 d，奶牛单独饲养在拴系牛栏中以测量乳脂肪酸谱，并使用网状采样技术，以乙二胺四乙酸二钠二水合物（EDTA）和醋酸镱作为食糜流动标记物来测定脂肪酸瘤网流入量。尽管红豆草日粮组的日粮C18:3n-3摄入量较低（P = 0.025），但饲喂红豆草日粮的奶牛单不饱和脂肪酸瘤网流入量更高（P = 0.042）。红豆草日粮组反式-9，反式-12-C18:2和顺式-12，反式-10 C18:2的瘤网流入量更高（P≤0.024）。与饲喂对照日粮的奶牛相比，饲喂红豆草日粮的奶牛顺式-9-C18:1和C18:3n-3的瘤胃表观生物氢化作用较低（P≤0.038）。与对照日粮组相比，红豆草日粮组乳脂肪酸谱中C18:3n-3和顺式-9，顺式-12-C18:2的比例更高（P≤0.018）。红豆草日粮中C18:2、C18:3n-3和不饱和脂肪酸从饲料到牛奶的转移效率更高（P≤0.0179）。基于这些结果，可以得出结论，在奶牛日粮中用红豆草青贮替代禾本科青贮可降低瘤胃中C18:3n-3的生物氢化作用，并改善乳脂肪酸谱。
