Lipid-induced depression of methane production and digestibility in the artificial rumen system (RUSITEC)

Abstract

. 1997. Lipid-induced depression of methane production and digestibility in the artificial rumen system (RUSITEC). Can. J. Anim. Sci. 77: 269-278. An artificial rumen (RUSITEC) equipped with eight fermenters was used to examine the effects of canola oil (CA), cod liver oil (CD) and coconut oil (CO) on methane production, dietary digestibility and rumen microbial populations. The experiment, repeated three times, involved two diets (100% grass hay or a 90%:10% wheat:hay mixture) either untreated (controls) or sprayed with CA, CD or CO (10%, wt/wt) in a 2 × 4 factorial arrangement. Dry matter disappearance and CH 4 production were greater (P < 0.05) from untreated concentrate diet than from untreated hay. There were significant interactions (P < 0.05) between diet and lipid type for DM digestion and several of the fermentation parameters. Coconut oil decreased (P < 0.05) DM and neutral detergent fibre disappearance of hay but did not affect digestion of concentrate. All oils, especially CO, depressed (P < 0.05) CH 4 production (mmol g -1 digestible DM) and methanogenic populations regardless of diet. Methanogens on CO-treated diets numbered less than 1% of those on CA-and CDtreated diets. Total viable, amylolytic, and cellulolytic bacterial numbers were also substantially reduced (P < 0.05) by CO, but not by CA or CD for both diets. Bacterial colonization and digestion of CO-treated hay was markedly less extensive than that observed on untreated, CA-or CD-treated hay. The molar proportion of propionate produced was increased (P < 0.05) by CA and CD, for the hay diet, but not for the concentrate diet. Coconut oil decreased (P < 0.05) the molar proportion of propionate produced on the hay diet and increased (P < 0.05) it on the concentrate diet. Of the three oils, CO was most inhibitory to CH 4 production and depressed fibre digestion. The CA and CD also decreased CH 4 production, but did not affect feed digestion in either diet. Consequently, the amount of metabolizable energy of feeds may be increased when diets are supplemented with these oils. Un rumen artificiel (RUSITEC), muni de huit fermenteurs a été utilisé pour examiner les effets de l'huile de colza canola (Ca), de foie de morue (Fm) et de coprah (Co) sur la production de méthane, sur la digestibilité des aliments et sur les populations microbiennes du rumen. L'expérience, conduite selon un dispositif factoriel 2 × 4 à trois répétitions, comportait deux régimes alimentaires : 100 % foin de graminée ou mélange blé (grain)-foin-foin, 90 : 10 %, servis non traités (témoin) ou avec 10 % en volume de Ca, Fm ou Co. La digestibilité apparente de la matière sèche et la production de CH 4 était plus importantes (P < 0,05) dans le régime concentré non traité que dans le régime au foin non traité. Il y avait des interactions significatives (P < 0,05) entre le régime et la nature des lipides pour la digestion de la m.s. et pour plusieurs paramètres de la fermentation. L'huile de coprah abaissait (P < 0,05) la digestion de la m.s. et de la NDF du foin, mais n'influait...

Mitigation strategies to reduce enteric methane emissions from dairy cows: Update review

“…Fats have also been shown to depress CH 4 production (Dong et al 1997a;Machmuller and Kreuzer 1999;Dohme et al 2000). It has been shown that the medium chain fatty acids (C 8 -C 16 ) cause the greatest reduction in CH 4 production (Dohme et al 2000).…”

“…The major problem associated with excessive fat addition (more than 5-6% of the ration) is that it depresses fiber degradation in the rumen (Dong et al 1997a;Mathison et al 1998), and reduces acetate production and milk fat content (Jenkins et al 1996;Ashes et al 1997). Mathison (1997) observed that digestibility of fiber was reduced with the addition of canola oil, such that the metabolizable energy content of the diet was not different from that of the control barley-based diet.…”

“…Mathison (1997) observed that digestibility of fiber was reduced with the addition of canola oil, such that the metabolizable energy content of the diet was not different from that of the control barley-based diet. Dong et al (1997a) observed that of the three oils (coconut, canola, and cod-liver oil) used in an artificial rumen system, coconut oil depressed fiber digestion the most. Although the addition of fats appears to reduce CH 4 production, excessive addition would not result in increased energy availability to the animal due to depressed fiber digestion.…”

Degradability and kinetics of fibrous particles in cattle fed diets based on corn silage and concentrates with or without addition of lipids

“…The presence of lipids creates a physical barrier on the surface of fibrous particles and prevents the action of bacterial enzymes on sites of potentially digestible NDF. Lipids reduce NDF degradation in the rumen (Ferlay and Doreau, 1992), but the magnitude of depression varies with lipid chemistry and quantity, animal species, and experimental conditions (Dong et al, 1997). Therefore, the usual recommendation is that the total fat content of diet should not exceed 50 g/kg of the feed dry matter (DM) to avoid depressions on intake and NDF digestibility, which, in its turn, would reduce the benefit of a larger energy density in the diet by the addition of lipid (Palmquist and Jenkins, 1980).…”

Methane production from dairy and beef heifers fed forages differing in nutrient density using the sulphur hexafluoride (SF6) tracer gas technique

“…Ruminant CH 4 production has in the past been measured using respiration calorimetry from which prediction equations relating CH 4 production to dietary components have been derived (Blaxter and Clapperton 1965;Moe and Tyrrell 1979;Holter and Young 1992). In-vitro techniques (Czerkawski and Breckenridge 1977;Dong et al 1997) and isotopic methods (Murray et al 1976;Frances et al 1993) have also been used. Conditions with the use of respiration chamber, in-vitro techniques, isotopic method and assumptions of prediction equations cannot be related to cattle under production situations, where environmental temperature, meal size and frequency, and selection of feed components can affect intake, rate of digestion and retention time in the rumen.…”