The Effects of Flavomycin, Salinomycin and Lasalocid on the Fermentation of Feed Ration Invitro

Veterinarni Medicina 38, 1993, 65-74

In our experiment the effects of flavomycin (F) - 6 ppm, salinomycin (S) - 12 ppm and lasalocid (L) - 33 ppm on the fermentation of feed ration consisting of hay and barley (80 : 20 %) were followed in a rumen pouch (Rusitec). The experiment lasted 14 days while the conditions of fermentation were stabilized within the first seven days. Samples of effluent, gases and undigested residues of feeds were taken for analyses on days 8 - 14. Dry matter digestibility (DMD) and organic matter digestibility (OMD) of the feed ration were not influenced by the addition of ionophores. The digestibility of detergent fibre however significantly decreased as a result of S and L additions. This was manifested in a decrease in the digestibility of acid detergent fibre by 10 % (S) and 7 % (L), neutral detergent fibre by 6 % (S) and 4 % (L), cellulose by 9 % (S) and 4 % (L), hemicellulose by 4 % (S) and 3 % (L). The total gas production decreased owing to the action of all ionophores, but the production of methane and CO2 was not observed. The production of total VFA as well as of propionic acid significantly increased due to the effects of only S and L by 71 % and 100 %, respectively. Since the production of acetic acid was not influenced, S and L decreased the acetate : propionate ratio by 41 % and 52 %, respectively. The production of n-butyric, n-valeric and isovaleric acids significantly decreased owing to the effect of S and L. Flavomycin did not have any effects on the production of total VFA, acetic and propionic acid and A : P ratio, but it significantly decreased the production of n-butyric and isobutyric acids and increased the production of n-valeric and isovaleric acids. The energy efficiency of the feed ration VFAs decreased as a result of the low effect of F on the VFA production and the values of end product fermentation - adenosine triphosphate production (ATP), glucose utilization, amount of fermented hexoses and fermented organic matter (OMF) - did not change in comparison with the control. The above-mentioned parameters of fermentation end-products as well as the energy efficiency of VFA significantly increased owing to the S and L effects. The efficiency of microbial matter synthesis expressed as Y(ATP) and the grammes of microbial nitrogen/kg OMF were also established in the experiment. Based on the determination of diaminopimelic acid (DAPA) in residual feed and microbial dry matter in the effluent, the total bacterial dry matter was found to decrease due to the effects of ionophores. If it were expressed in g/kg of digested DM of the residual feed and ATP production in mol/kg of digested DM, the value of Y(ATP) would be calculated. Y(ATP) however significantly decreased, in comparison with the control (12.41) only due to the effects of S (8.29) and L (9.34). The efficiency of microbial N/kg OMF also significantly decreased after S and L additions from 24.94 (control) to 18.84 (S) and 22.02 (L). The bacterial and protozoal dry matter of the effluent and residual feed determined by differential centrifugation was significantly reduced by all three ionophores. This was manifested in the decreased production of ammonia nitrogen in the effluent but this decrease was only significant after the S and L additions. It si evident that the individual ionophores did not exhibit the same effects on the fermentation of feed ration in this experiment. Salinomycin and lasalocid significantly influenced the basal and end products of fermentation and efficiency of microbial matter synthesis. Flavomycin influenced the feed ration fermentation to a small extent only, this was probably due to the use of the lower, less effective dose

FULL PAPER on request
« back