Ultra-high-temperature (UHT) pasteurization of skim milk (148 °C for 3 s) has been found to inactivate effectively foot and mouth disease virus. For determination of the effect of UHT pasteurization on milk proteins, the composition and properties of proteins from milk after this treatment were compared with those from conventional high-temperature-short-time pasteurized (HTST = 71.7 °C for 15 s) and raw skim milks. Vacuum-dried-acid-precipitated caseins and freeze-dried-dialyzed whey proteins were prepared from each product. Functional properties of casein such as solubility, viscosity, emulsifying capacity, and electrophoretic mobility were compared. For both casein and whey proteins, compositional comparisons were made among molar ratios of amino acids, total protein, and chemically available lysine.The solubility of milk caseins was reduced by UHT pasteurization. Whey protein nitrogen analyses show significant protein denaturation. No significant losses in nutritive value are indicated, and differences in viscosity and emulsification capacity are small.

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Methods of preparing encapsulated, or protected vegetable oil supplements for feeding ruminant animals to increase the polyunsaturation in milk and meat fat are outlined. The C 18:2 content of milk from cows fed increasing amounts of protected safflower oil during a 6 week dose‐response experiment increased from 3 to 30% of total fat. At high levels of C 18:2 in milk fat, whole milks tended to develop an oxidized flavor, which was slight in fresh raw milk but increased markedly after 24 hr. Addition of an antioxidant to fresh milk suppressed this off‐flavor. Creams containing high levels of C 18:2 required longer aging times than normal cream for satisfactory churning. Butter containing 16% or more of C 18:2 was soft and somewhat sticky but was much more readily spreadable at refrigerator temperatures than normal butter. Veal fat from supplement fed calves had four times as much C 18:2 as fat from controls.

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.