Comparison of the Effect of using Chemical Buffer and Acid-Consuming Bacteria on Digestibility and Fermentation, Growth Performance and Meat Quality of Lambs Fed with High Concentrate Diets

High concentrated diets are rapidly degraded in the rumen and lower ruminal pH by rapid and high lactic acid production. The use of chemical or biological buffers improves digestion and fermentation conditions in a high concentrate diet. The aim of this study was to compare the effect of using acid-consuming bacteria as pH regulator (biological buffer) and chemical buffer to improve digestibility and fermentation of high concentrate diets.

In the present experiment, 21 fattening Arabi male lambs with an average weight of 34.35±2.50 kg and an average age of 8±1 months old were used in a completely randomized design with 3 treatments and 7 replications for 50 days. Experimental treatments were included: 1- control diet (70% concentrate and 30% forage, without buffer and bacteria), 2- control diet + 1% sodium bicarbonate buffer, 3- control diet + 3 ml of Megasphaera elsdenii bacteria with 2 gram yeasts of Saccharomyces cerevisiae (bacterial-yeast).

Nutrient digestibility and growth performance parameters were not affected by experimental treatments. Rumen protozoa population was significantly higher in bacterial-yeast treatment than control (p<0.05). Ammonia nitrogen concentration and ruminal pH were affected by experimental treatments, and compared to control treatment, in treatments containing chemical or biological buffer, ruminal pH increased and ammonia nitrogen decreased. But blood and liver parameters, carcass characteristics such as size and weight of carcass parts, meat colorimetric characteristics were not affected by experimental treatments (p<0.05).

Overall, the results of the present experiment showed that the use of acid-consuming bacteria as pH regulators has competitive effects with bicarbonate buffer and even better in some cases.