The Effects of using Acid-Consuming Bacteria and Different Buffers with High Concentration Diets on In Vitro Digestion and Fermentation Activity of Anaerobic Bacteria and Fungi of Fattening Lambs Rumen

The use of chemical buffers such as sodium bicarbonate, and bacterial additives like Megasphaera elsdenii result in improving the digestibility and fermentation in high concentration diets. Therefore, this research was conducted to compare the effect of acid-consuming bacteria and different chemical buffers for improvements in digestion and fermentation of high concentration diets.

Several chemical buffers were used alone or together with Megasphaera alsdeni bacteria as biological buffers. Two-step digestion methods and specific cultures of anaerobic rumen fungi and bacteria were used in this experiment. The number of 12 treatments includes 1- the control diet (without additives and containing 70% concentrate + 30% fodder or basic diet), 2- the basic diet + 3 ml of Megasphaera alsdeni bacteria (1.5 x 108 CFU/ml), 3 to 12- One percent of the 5 buffers were bentonite-sodium, sodium bicarbonate, magnesium oxide, zeolite, sodium sesquicarbonate alone or together with Megasphaera alsdeni bacteria.

In the two-step digestion test, the digestibility of dry matter was improved in the treatments receiving buffer and bacteria (p<0.05). The digestibility of dry matter, neutral detergent fiber, and acid neutral detergent fiber by rumen fungi was affected by the experimental treatments and was higher in the treatment containing chemical buffer + bacteria than in the control (p<0.05). The use of chemical and biological buffer had a significant effect on the digestibility of nutrients by rumen bacteria and it was more in the treatments containing buffer + bacteria than in the control (p<0.05). The fermentation parameters of the culture medium of bacteria and fungi, including pH and ammonia nitrogen concentration, were significantly affected by the experimental treatments; pH and ammonia nitrogen concentration were higher and lower than the control treatment in all treatments, respectively (p<0.05).

Therefore, according to the results of the present experiment, the use of chemical buffer improved the conditions of digestion and fermentation of high-concentrate diets for fattening lambs, and in many cases, the effect of acid-consuming bacteria was competitive with chemical buffers. On the other hand, the combined use of bacteria and buffer also had synergistic effects.