The Determination of Buffering Capacity of Some Ruminant's Feedstuffs and their Cumulative Effects on TMR Ration

Two experiments have been conducted in order to investigate the buffering capacity of some ruminant's feedstuffs and their additivity to calculate ration buffering capacity as a tools for feed formulation. The first experiment was performed with different types (65 samples) of feedstuffs to determine the Buffering Capacity (BC) and Buffer Value Index (BVI). For investigation of cumulative effects of buffering capacity or buffer value index, 6 Total Mixed Rations (TMR) for dairy cow and other six TMR for sheep were formulated using the feedstuffs with known BC or BVI. The calculated and analyzed values were compared using paired t-test. In the second experiment rumen fluid pH was measured using 5 simple rations on 5 adult sheep and correlation was calculated between rumen fluid pH and fiber or ash content of the diets. The analyzed BC and BVI for all the TMRs appeared to be lower than the values calculated from these variables, for individual feedstuffs (p<0.05). The analyzed BVI was also two times higher than the calculated BVI for each diet (p<0.05). In spite of this, the correlation (0.88) between calculated and analyzed values was strong and positive (p = 0.021) for BC and for BVI (0.64) (p and 0.172), respectively. No significant correlation was detected between BC or BVI and non-fiber carbohydrate (NFC) or fiber content of diets (p>0.05). No significant (p>0.05) correlation has been found between ruminal fluid pH and dietary components.