D. F. Jones*,
W. P. Weiss* 1,
D. L. Palmquist*,
T. C. Jenkins+
*The Ohio State University Department of Animal Sciences
+Department of Animal, Dairy, and Veterinary Sciences, Clemson University
Diets with no supplemental fat or supplemented with 3% tallow, fish oil, or fish oil treated with ethanolamine to form the ethylamide were fed to 32 Holstein cows. Cows were fed the diets (23% alfalfa silage, 31% corn silage, and 46% concentrate) once daily for four weeks. Fish oil fatty acids decreased DMI while milk and milk component yields were decreased by all fat supplements. No treatment effects on fat and protein concentrations were observed; however, milk fat percentage was low for all. Fat supplemented cows had decreased proportions of 6:0-14:0 milk fatty acids, with proportions being higher for fish oil than for tallow. Fat supplemented cows increased 16:1, 17:0, trans 18:1, conjugated linoleic acid (CLA) and all long-chain polyunsaturated fatty acid. Compared with tallow, fish oil increased all unsaturated fatty acids except cis 18:1 which was lowered. Treated fish oil fatty acids decreased trans 18:1, 18:2, 20:4 n-6, 20:5 n-3, and 22:5 n-3 in milk compared with fish oil. Compared with the control, fish oil treatments decreased 18:0 and cis 18:1 and increased trans 18:1 in milk.
1For more information, contact at: The Ohio State University, Ohio Agricultural Research and Development Center, 314 Gerlaugh Hall, 1680 Madison Avenue, Wooster, OH 44691; 330-263-3622; e-mail: weiss.6@osu.edu