Formaldehyde-treated casein–safflower oil supplement for dairy cows: I. Effect on milk composition

Abstract

SummaryThe effects of feeding lactating cows a daily supplement of 1 kg formaldehyde-treated casein–safflower oil (1:1, w/w) on the milk composition are reported. Three breeds, Jersey, Sahiwal and Sahiwal × Jersey crossbred were used.The formaldehyde treatment not only eliminated the suppressing effect on the milk, fat and protein yields and on the fat and protein contents usually encountered when such a level of unsaturated oil is fed to lactating cows, but also resulted, on the average, in 15 and 6% increases in the fat and protein contents respectively.The formaldehyde-treated dietary supplement also caused a decline of 5% in the solids-not-fat content, presumably due to a decrease in the lactose content.It is suggested that the formaldehyde treatment protects the casein from the ruminal proteolysis and this in turn prevents the encapsulated unsaturated oil from biohydrogenation and eliminates the diverse effects on rumen microflora and environment.