EFFECT OF LIPID SUPPLEMENTATION ON RUMINAL EPITHELIAL MEMBRANE FATTY ACID COMPOSITION AND SHORT-CHAIN FATTY ACID ABSORPTION
Verdugo, Ana C 1990-
Inclusion of lipid into diets increases the energy density and, depending on the type of lipid, may alter the fatty acid (FA) composition of tissues. Effects of dietary lipid on the digestive and immune function gastrointestinal tract have been evaluated, but effects on how dietary FA affect short-chain fatty acid (SCFA) absorption have not been investigated. The objective of this study was to determine the effect of dietary lipid supply and lipid type on the FA composition of the ruminal epithelium and absorption of SCFA. Twenty-one Holstein steers (194.1 ± 26.77 kg) were randomly assigned to the control (CON; 2.2% ether extract) or 1 of 2 lipid supplementation treatments (5% ether extract) utilizing saturated (SAT) or unsaturated sources and protected fat (UNSAT). After 30 d, calves were killed and samples of ruminal digesta, blood, and ruminal tissue were collected for FA analysis, and ruminal tissue was used for ex vivo measurement of acetate, propionate, and butyrate uptake and flux. Data were analyzed as a randomized complete block design using the mixed model of SAS with the fixed effect of treatment and the random effect of block. Calves fed SAT and UNSAT had greater (P < 0.01) concentration of total FA in ruminal fluid than CON. Feeding UNSAT increased the monounsaturated (P < 0.001) and polyunsaturated (P = 0.002) FA content in ruminal fluid relative to SAT and CON. The concentration of FA in the ruminal epithelium did not differ among treatments but there was a tendency (P = 0.069) for SAT calves to have more total FA and saturated FA (P = 0.053) than UNSAT. Moreover, UNSAT calves had greater (P = 0.006) omega-3 FA concentration in the ruminal epithelium than CON and SAT calves. Calves fed SAT had greater (P = 0.038) total propionate uptake with greater passive diffusion (P = 0.015) than CON and UNSAT. Calves fed SAT also had greater total butyrate uptake (P = 0.008). However, there were no differences for acetate, propionate, or butyrate flux among treatments. Thus, it is concluded that the provision of dietary lipid alters the FA composition of the ruminal epithelium and the uptake of propionate and butyrate with the greatest response when saturated lipid sources are provided.
DegreeMaster of Science (M.Sc.)
DepartmentAnimal and Poultry Science
CommitteeMcKinnon, John; Van Kessel, Andrew; Buchanan, Fiona; Alexander, Trevor
Copyright DateDecember 2016
Lipid, Ussing Chamber, short-chain fatty acid, epithelium