Most of us are familiar with Acid Buf, a calcified marine algae harvested on the coast of Iceland. Acid Buf is mainly used as a rumen buffer to assist in increasing and stabilizing the rumen pH.
Acid Buf is a long acting rumen buffer, able to buffer up to 8 hours at a pH of 5.5.
Acid Buf contains 30 % highly bioavailable Ca.
Ca in Acid Buf is 5 to 6 times more bioavailable than Ca from Limestone at rumen pH levels.
Acid Buf contains 5.5% highly bioavailable Mg.
Magnesium in Acid Buf can be between 2 and 3 time more bioavailable in the rumen than Magnesium from commercially available MgO. This is important because apart from acting as an alkalizer in the rumen, absorption of Magnesium is the most efficient in the rumen with no significant absorption in the omasum, abomasum or small intestine (Tomas and Potter, 1976. Br J Nutr. ;36(1):37-45.).
Acid Buf can replace Na-bicarbonate in ruminant diets as follows: 80 g Acid Buf ≈ 160 g Na-bicarbonate + 56 g Limestone + 8g MgO.
When replacing Na-bicarbonate with Acid Buf, one should make sure that the diet contains at least 66 g of Na / cow / day (Brian Tarr, Nutreco report).
This creates space in the diet that can be used to increase the nutrient density of the diet.
Replacing Na-bicarbonate with Acid Buf could reduce the DCAD value of the diet as the DCAD value of Acid Buf is almost neutral. Bernard et al, 2014, indicated that lower DCAD value due to replacing Na-bicarbonate with Acid Buf (28 vs 17), did not have a negative effect on production.