|
KMID : 1025520040460030355
|
|
Journal of Animal Science and Technology
2004 Volume.46 No. 3 p.355 ~ p.372
|
|
|
Effects of Added Vegetable Oils on In vitro Formation of Fatty Acid Soaps and Fermentation Characteristics and NDF Disappearance Rate
|
|
Kim D. I.
Choi J. R.
Lee Y. H.
Lee J. K.
Chung T. Y.
|
|
|
Abstract
|
|
|
|
In vitro experiments were conducted to determine the formation of fatty acid soaps (FAS) and neutral detergent fiber (NDF) disappearance rate. The substrates were a basal alfalfa hay containing 1) no oil, 2) 10% soybean oil, 3) 10% corn oil, on a weight basis. All the substrates were incubated in triplicate for 0, 3, 6, 12, 24 and 48h in each experiment. After the incubation in the first experiment serum bottles (60ml) were analyzed for nonesterified, esterifed and fatty acid soaps contents. The serum bottles (120ml) from the second experiment were analyzed for pH, NH3-N and VFA concentration, and dry matter and NDF disappearance rate. pH decreased and the concentration of NH3-N increased significantly with longer incubation time (P<0.0001). The disappearance rates of dry matter and NDF significantly varied with feed, incubation time and oils (P<0.05). The molar concentration of total VFA increased and proportion of acetate significantly decreased with incubation time (P<0.0001), but the proportion of propionate significantly increased with longer incubation time (P<0.0001). Addition of oils to diet lowered the ratio of acetate:propionate (P<0.05). The esterified fatty acids (EFA) decreased with increasing incubation time (P<0.0001), and nonesterified fatty acids (NEFA) increased due to lipolysis of EFA. NEFA then reacted with cations to increase formation of FAS. The formation of FAS increased significantly at 48h of incubation time (P<0.0001). Especially, formation of stearic acid soaps was 27.5 and 32.5 folds with soybean oil and corn oil supplements, respectively, by 48h of incubation time (P<0.0001). Alfalfa hay had higher cation contents, particularly Ca, which react with NEFA and FAS can be formed with longer incubation time. Saturated fatty acids had a higher proportion of FAS than did unsaturated fatty acids, suggesting that the former may react more extensively with cations. FAS contents increased with increasing chain length of the fatty acids. Since added vegetable oils formed FAS, it might decrease negative effects on in vitro fermentation characteristics and NDF disappearance rate.
|
|
|
KEYWORD
|
|
|
Vegetable oil, Fatty acid soaps, NDF disappearance rate, In vitro
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|
|