Submitted to: Journal of Dairy Science
Publication Type: Abstract only
Publication Acceptance Date: 7/25/2005
Publication Date: 7/25/2005
Citation: Faciola, A.P., Broderick, G.A., Hristov, A.N., Leao, M.I. 2005. Effect of different levels of lauric acid on ruminal protozoa, fermentation pattern, and milk production in dairy cows [abstract]. Journal of Dairy Science. 88 (suppl. 1):178. Interpretive Summary:
Technical Abstract: Reducing ruminal protozoa may improve N utilization. Medium-chain saturated fatty acids such as lauric acid (C12:0) have been shown to suppress protozoa. Fifty-two Holstein cows (eight fitted with ruminal cannulae) were used to test the effectiveness of different levels of lauric acid (LA) for suppressing protozoal population in the rumen; milk production, ruminal parameters and DMI also were measured. Cows were randomly assigned to four treatments: A) Control, B) 80, C) 160, or D) 240g/d of LA that was given in the TMR once a day for 8-wk. Prior to starting feeding the LA, all cows were fed the same diet (control) for a 2-wk covariate period and production of milk and protozoal counts were determined for use in statistical analysis. The TMR contained (DM basis): 29% alfalfa silage, 35% corn silage, 14% rolled high moisture corn, 8% soybean meal, 12% corn grain ground dry, 15.5% CP and 29% NDF. Cows were fed ad libitum, protozoal counts, pH measurement, and ruminal sampling were done every two weeks. Data were analyzed using proc mixed in SAS. The results are reported in the table below. LA fed on the diets at 80, 160, and 240 g/d did not reduce DMI, did not affect ruminal pH, ruminal parameters, or milk production. LA fed at 160 and 240 g/d on the TMR of Holstein’s dairy cows reduced ruminal protozoal population by only 25 and 30% respectively, showing that these levels on the diet were not sufficient to achieve a concentration within the rumen that promote the anti-protozoal effect of LA.