|Faciola, A - U FEDERAL DE VICOSA|
|Hristov, A - U OF IDAHO|
|Leao, M - U FEDERAL DE VICOSA,|
Submitted to: Journal of Dairy Science
Publication Type: Abstract Only
Publication Acceptance Date: July 26, 2004
Publication Date: July 26, 2004
Citation: Faciola, A.P., Broderick, G.A., Hristov, A.N., Leao, M.I. 2004. Effect of two forms of lauric acid on ruminal protozoa and fermentation pattern in dairy cows. [abstract]. Journal of Dairy Science. 87(1):53. 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. Six Holstein cows fitted with ruminal cannulae were used to test the effectiveness of two different forms of lauric acid (LA) for suppressing protozoal population in the rumen; ruminal parameters and DMI also were measured. Cows were randomly assigned to three treatments: 1) Control, 2) 160g/d of LA, or 3) 160g/d of sodium laurate (NaLA, dissolved in 1,600 ml of water). Both LA and NaLA were given in a single dose into the rumen via cannulae before morning feeding. The TMR contained (DM basis): 15% alfalfa silage, 40% corn silage, 30% rolled high moisture corn, 14% soybean meal, 16.6% CP and 29% NDF. Cows were fed ad libitum, protozoal counts were done daily, pH was measured weekly, and ruminal fluid was collected in the last week and analyzed for metabolites. Data were analyzed using proc mixed in SAS. The results are reported in the table below. Protozoa declined rapidly with dosing of both LA and NaLA, approaching the final populations within 3 days. Ruminal ammonia and total free AA decreased with LA and NaLA in parallel to protozoa, suggesting reduced intraruminal turnover of bacterial protein. The results showed that LA, which is less expensive, was equivalent to NaLA for reducing ruminal protozoa, obviating the need to convert LA to NaLA under practical conditions.