Freitas Júnior José E, Bettero Vitor P, Zanferari Filipe, Del Valle Tiago A, De Paiva Pablo G, Ferreira De Jesus Elmeson, Takiya Caio S, Leite Laudi C, Dias Márcia, Rennó Francisco P
a Department of Animal Nutrition and Animal Production , University of São Paulo , Pirassununga , Brazil.
b Department of Animal Sciences , Federal University of Bahia , Salvador , Brazil.
Arch Anim Nutr. 2019 Jun;73(3):171-193. doi: 10.1080/1745039X.2019.1595886. Epub 2019 Apr 29.
This study was designed to determine the rumen outflow of fatty acids (FA) and biohydrogenation (BH) extent using alternative sampling sites (reticulum and omasum) to abomasum in dry cows fed different sources of FA. Four Holstein non-pregnant dry cows (≥3 parturitions, and 712 ± 125 kg BW), cannulated in the rumen and abomasum, were randomly assigned to a 4 × 4 Latin square design experiment, containing the following treatments: 1) control (CON); 2) soya bean oil (SO), dietary inclusion at 30 g/kg; 3) whole raw soya beans (WS), dietary inclusion at 160 g/kg; and 4) calcium salts of FA (CSFA), dietary inclusion at 32 g/kg. Rumen outflow of nutrients was estimated using the three markers reconstitution system (cobalt-EDTA, ytterbium chloride, and indigestible neutral detergent fibre [NDF]). Diets with FA sources decreased feed intake and increased FA intake. No differences in nutrient intake and digestibility were detected among cows fed diets supplemented with different FA sources. Diets with FA sources reduced the rumen outflow of DM and NDF, hence decreasing their passage rates. In addition, SO diet reduced the ruminal outflow of DM and NDF in comparison with WS and CSFA. Omasal sampling yielded the highest values of rumen outflow of NDF and potentially degradable NDF (pdNDF), whereas the reticular and abomasal samplings yielded intermediate and least values, respectively. The interaction effect between diet and sampling site was observed for rumen outflow of majority FA (except for C16:0, C18:0, and C18:2 trans-10, cis-12) and BH extension of C18:1 cis, C18:2, and C18:3. Calculations derived from abomasal sampling revealed that WS and CSFA diets had lower BH extent of C18:1 cis and C18:2 in comparison with SO, whereas cows fed CSFA had greater BH extent of C18:3 and lower BH extent of C18:1 cis compared to those fed WS. However, the latter results were not similar when calculations were performed based on the reticular and omasal samplings. Thus, there is evidence that neither reticular nor omasal samplings are suitable for estimating rumen outflow of FA in dry cows. In addition, WS and CSFA diets can increase the abomasal flow of polyunsaturated FA in dry cows.
本研究旨在通过使用不同脂肪酸来源的干奶牛的替代采样部位（网胃和瓣胃）至皱胃，来确定脂肪酸（FA）的瘤胃流出量和生物氢化（BH）程度。四头荷斯坦非妊娠干奶牛（≥3胎，体重712±125千克），瘤胃和皱胃安装有瘘管，被随机分配到一个4×4拉丁方设计实验中，包含以下处理：1）对照（CON）；2）大豆油（SO），日粮添加量为30克/千克；3）全生大豆（WS），日粮添加量为160克/千克；4）脂肪酸钙盐（CSFA），日粮添加量为32克/千克。使用三种标记物重构系统（钴-乙二胺四乙酸、氯化镱和不可消化中性洗涤纤维[NDF]）估计营养物质的瘤胃流出量。含有脂肪酸来源的日粮降低了采食量并增加了脂肪酸摄入量。在饲喂不同脂肪酸来源补充日粮的奶牛之间，未检测到营养物质摄入量和消化率的差异。含有脂肪酸来源的日粮降低了干物质和中性洗涤纤维的瘤胃流出量，从而降低了它们的通过率。此外，与全生大豆和脂肪酸钙盐相比，大豆油日粮降低了干物质和中性洗涤纤维的瘤胃流出量。瓣胃采样得到的中性洗涤纤维和潜在可降解中性洗涤纤维（pdNDF）瘤胃流出量值最高，而网胃和皱胃采样分别得到中间值和最低值。对于大多数脂肪酸的瘤胃流出量（除C16:0、C18:0和反式10，顺式12 C18:2外）以及顺式C18:1、C18:2和C18:3的生物氢化程度，观察到日粮和采样部位之间的交互作用。从皱胃采样得出的计算结果表明，与大豆油相比，全生大豆和脂肪酸钙盐日粮中顺式C18:1和C18:2的生物氢化程度较低，而与饲喂全生大豆的奶牛相比，饲喂脂肪酸钙盐的奶牛C18:3的生物氢化程度较高，顺式C18:1的生物氢化程度较低。然而，当基于网胃和瓣胃采样进行计算时，后一结果并不相似。因此，有证据表明网胃和瓣胃采样均不适用于估计干奶牛脂肪酸的瘤胃流出量。此外，全生大豆和脂肪酸钙盐日粮可增加干奶牛皱胃中多不饱和脂肪酸的流量。
