title: Increasing polyunsaturation of milk fats by feeding formaldehyde protected sunflower-soybean supplement.
abstract: A practical means of protecting fats of a feed concentrate containing high polyunsaturated fatty acids is described. A ground mixture of 30% soybeans and 70% sunflower seeds was treated with 1% formaldehyde to protect the unsaturated lipids from microbial hydrogenation in the rumen. This was fed as a supplement to two Holstein cows in amounts that were doubled weekly. These ranged from 524 to 8384 g/day and provided successively increasing intakes of 100, 200, 400, 800, and 1600 g of linoleic acid daily. Percent milk fat increased by more than one, and linoleic acid (C18:2) of milk fat increased from 2.5 to 20% with compensatory declines in myristic (C14:0) and palmitic (C16:0) acids. Cholesterol and vitamin E of plasma both doubled at the highest supplementation. Milk yield, solids-not-fat, protein and milk cholesterol were unaltered. Fat in feces doubled from about 3 to 6%. Daily linoleic acid content of feces increased from 25 g to 120 g, indicating a dietary loss of 7 to 10% of this polyunsaturated acid. These cheaper feed ingredients elevated the polyunsaturated fats in milk as effectively as the expensive purified casein and safflower oil supplements in previous experiments.
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D002417:Cattle; D002784:Cholesterol / Q000378:metabolism; D004041:Dietary Fats / Q000032:analysis; D004063:Digestion; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D005243:Feces / Q000032:analysis; D005260:Female; D005557:Formaldehyde / Q000378:metabolism; D006368:Helianthus; D007774:Lactation; D050356:Lipid Metabolism; D008892:Milk / Q000378:metabolism*; D008894:Milk Proteins / Q000378:metabolism; D011247:Pregnancy; D012639:Seeds; D013025:Glycine max; D014810:Vitamin E / Q000097:blood
chemical_list: D004041:Dietary Fats; D005231:Fatty Acids, Unsaturated; D008894:Milk Proteins; D014810:Vitamin E; D005557:Formaldehyde; D002784:Cholesterol