Effect of Forage to Concentrate Ratio and Monensin Supplementation on cis-9, trans-11 Conjugated Linoleic Acid and trans-11 Octadecenoic Acid Concentrations of Ruminal Contents and Plasma in Sheep
Asian-Australasian Journal of Animal Sciences
Twenty-four cannulated Small-tailed Han×Poll Dorset wethers (BW 47.5±2.1 kg) were used to determine the effects of forage to concentrate ratio (40:60 vs. 70:30), monensin supplementation (0, 15 or 30 ppm, DM basis) and interactions of these two factors on cis-9, trans-11 conjugated linoleic acid (cis-9, trans-11 CLA) and trans-11 octadecenoic acid (trans11-C 18:1 ) concentrations in ruminal contents and plasma in sheep. The experiment was designed as a 2×3 factorial. The diet contained Chinese
... contained Chinese wild rye grass hay (Aneurolepidium Chinese), cracked corn, soybean meal, NaCl, limestone and trace mineral premix. Dietary crude fat and linoleic acid (C 18:2n-6 ) were adjusted with soybean oil to about 7.0% and 24.0 mg/g (DM basis), respectively. High forage diets increased (p<0.001) the concentrations of trans11-C 18:1 and cis-9, trans-11 CLA in ruminal contents and plasma. Monensin supplementation increased (p<0.001) the concentration of trans11-C 18:1 in ruminal contents, but had no effect on that of cis-9, trans-11 CLA. Concentrations of trans11-C 18:1 (p<0.019) and cis-9, trans-11 CLA (p<0.022) in plasma increased with dietary monensin levels. Interactions of forage: concentrate ratio and monensin level tended to affect the concentrations of trans11-C 18:1 (p<0.091) and C 18:2n-6 (p<0.083) in ruminal contents. Increasing forage levels increased the concentrations of trans11-C 18:1 and cis-9, trans-11 CLA in the rumen. Supplementing with monensin increased the ruminal production of trans11-C 18:1 and concentrations of trans11-C 18:1 and cis-9, trans-11 CLA in plasma.