title: Feeding polyunsaturated vegetable oils to lactating cows.
abstract: Holstein cows fed concentrate:hay diets also were fed for 14 days supplements of soybean oil plus casein, soybean oil protected from ruminal hydrogenation by encapsulation in a casein-formaldehyde matrix, cottonseed oil plus casein, or cottonseed oil protected with casein formaldehyde. The supplements were fed at rates to give a linoleic acid (18:2) intake of 225 g/day. Yields of milk and milk protein were not affected by treatment. Milk 18:2 was not increased by the unprotected soybean oil or cottonseed oil but was increased by protected soybean and cottonseed oil from a control of 2.3 to 5.7% of total milk fat. Milk 18:0 and 18:1 also increased. Compensatory declines were observed in milk 16:0 and 14:0 acids. In fecal fatty acids during the treatment periods, percentage of 18:2 of the total fat decreased and 18:0 markedly increased. These results indicate hydrogenation of the dietary oils in the alimentary tract or a differential absorption. Fecal 16:0 and 14:0 decreased.
mesh_terms: D000818:Animals; D002364:Caseins / Q000378:metabolism; D002417:Cattle / Q000378:metabolism* / Q000502:physiology; D002784:Cholesterol / Q000097:blood; D003369:Cottonseed Oil; D004734:Energy Metabolism; D005227:Fatty Acids / Q000096:biosynthesis; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D007774:Lactation; D008892:Milk / Q000378:metabolism; D008894:Milk Proteins / Q000096:biosynthesis; D009821:Oils / Q000378:metabolism*; D011247:Pregnancy; D013025:Glycine max
chemical_list: D002364:Caseins; D003369:Cottonseed Oil; D005227:Fatty Acids; D005230:Fatty Acids, Nonesterified; D008894:Milk Proteins; D009821:Oils; D002784:Cholesterol