In vitro study of the effect of different ionophore antibiotics and of certain derivatives on rumen fermentation and on protein nitrogen degradation

Abstract

Summary -An in vitro study was carried out to evaluate the effect of different ionophore antibiotics and some of their derivatives on rumen fermentation and on the degradation of peanut meal nitrogen. The increase in the production of propionic acid at the expense of acetic acid, observed with lonomycin, nigericin, cationomycin and lysocellin, was identical to that noted with monensin. The decrease in methanogenesis observed in the presence of monensin was also found with cationomycin and lysocellin. With the exception of lysocellin, which greatly reduced protein degradation of peanut meal, and of nigericin, which had no effect on this parameter, the 2 other molecules presented the same action as monensin. The negative effect of monensin on microbial ammonia uptake was demonstrated with the same intensity in the presence of cationomycin; it was slightly higher with nigericin and particularly accentuated with lonomycin and lysocellin. Three ester derivatives of monensin (monensin acetate, monensin propionate and monensin butyrate) had a similar action to that of monensin on the orientation of rumen fermentations. The monensin isobutyrate derivative appeared to be more active than monensin and only weakly altered microbial ammonia uptake. The oxolonomycin and hydroxolonomycin derivatives behaved identically to lonomycin with respect to microbial metabolism and protein nitrogen degradation. Unlike the molecules from which they derive, the deacylated cationomycin and nigericic acid had no effect on the orientation of rumen fermentations. Of the compounds tested and presenting a potential 'growthpromoting action' at least comparable to that of monensin, and which demonstrated lower toxicity on mice, three molecules (oxolonomycin, lysocellin and

Effects of lasalocid and cationomycin on the digestion of plant cell walls in sheep

“…Characterization of in vitro fermentations in the batch-type fermenter described by Jouany and Thivend (1986) for 6 h or in Rusitec, sometimes indicated that cationomycin and lasalocid did not alter methane production whether the rumen contents were adapted to the ionophore (Bogaert et al 1989a) or not (Gaboyard 1987;Hillaire et al 1989 …”

Effects of a source of ruminally degradable protein and monensin on starch digestion in steers fed a high-grain diet

“…Increased molar proportions of isovalerate with addition of monensin to the SBM diet (P*M interaction, P<.001) were also observed. Molar proportions of isobutyrate and isovalerate have been reported to be decreased by ionophore (Russell and Martin, 1984;Hillaire et al, 1989;Clary et a!., 1993;Ali HaTmoud et al, 1995). The effect of ionophore on branched-chain VFA is related to its effects on ruminal feed N degradation.…”