Published online by Cambridge University Press: 02 September 2010
1. The effect of feeding a salt solution containing ammonium acetate on the yield and fatty acid composition of cows' milk fat has been studied.
2. The trials involved eighteen lactating Jersey cows. In the first trial one group of 5 cows was fed the treatment diet throughout an experimental period of 10 weeks and another group of 5 cows acted as controls. In the second trial which extended over four 28-day periods, two groups of 4 cows spent alternate periods on treatment or control diets. The overall results of the two trials were in agreement.
3. The outputs of C4-C14 acids and of palmitic acid per kg of milk yielded were greater than the intakes. The output of C18 acids was less than the intake per kg of milk yielded. These observations were noted on both treatment and control.
4. Treatment resulted in an increased secretion of C4-C14 acids and of palmitic acid and a decreased secretion of C18 acids per kg of milk yielded.
5. The results have been discussed in the light of present knowledge concerning the synthesis of fat in the mammary gland.