Coconut Fatty Acid Distillate Ca-Soap with Different Calcium Sources: Effects of Varied Proportions of Protected and Unprotected Fat Supplementation in Dairy Rations

This study aimed to compare calcium oxide (CaO) and calcium chloride (CaCl₂) as calcium sources for coconut fatty acid distillate (CFAD) calcium soap (Ca-soap) production and to evaluate the supplementation ratios of unprotected and protected CFAD in dairy rations to optimize rumen function. This research included two steps: (1) assessing the protection strength of Ca-soap made with CaO and CaCl₂ at mole ratios of Ca to CFAD of 1, 1.5, 2, and 2.5; (2) evaluating CFAD supplementation in an in vitro dairy ration study using a 5 × 4 randomized factorial block design. Factor A compared unprotected and protected CFAD ratios of A1 = 100:0, A2 = 75:25, A3 = 50:50, A4 = 25:75, and A5 = 0:100, and factor B compared supplementation levels of B1 = 0%, B2 = 1%, B3 = 2%, and B4 = 3%. CaCl₂ at a 2.5-mole ratio to CFAD produced the lowest acid value and the carboxylic acid (C=O) chemical bond. Complete protection (0:100) exhibited the highest densities of <i>Bacteroides</i> and nutrient digestibility (<i>p</i> < 0.05) without significantly affecting rumen fermentability (<i>p</i> > 0.05). Higher CFAD levels significantly reduced methanogens and protozoa (<i>p</i> < 0.05) without significantly affecting estimated methane production. In conclusion, CaCl₂ at a 2.5-mole ratio to CFAD provided the best protection, and its complete protection in CFAD supplementation optimized rumen function.