Comparative Effects of Tallow, Lard and Soybean Oil, with and without Supplemental Cholesterol, on Growth, Tissue Cholesterol and Other Responses of Calves

Three groups of male Holstein calves, 4 to 14 days of age, were fed for 23 weeks a recostituted milk containing 9% nonfat dry milk solids and 3.5% tallow, lard, or refined soybean oil. All diets were supplemented with vitamins and minerals. Half of the calves in each group received supplemental cholesterol in the milk at 175 mg per 100 g milk. Milk was fed at a daily rate of 100 g per kg body weight. Blood samples and body weight were taken weekly, and all calves were slaughtered at the end of the experiment. Plasma cholesterol was higher (P < 0.01) in calves fed supplemental cholesterol than in those receiving none and was higher (P < 0.10) in those fed tallow and lard than in those fed soybean oil. Supplemental cholesterol significantly increased body weight gains (P < 0.05) and cholesterol content of the liver (P < 0.01) but had no significant effect on cholesterol content of muscle, fat, brain, aorta, and coronary arteries. As compared with calves fed the other diets, those fed soybean oil had significantly higher cholesterol, per unit dry tissue, in the liver (P < 0.05), muscle (P < 0.01), fat (P < 0.01), aorta (P < 0.05), and coronary arteries (P < 0.01). They also had smaller body weight gains (P < 0.05) and lower plasma calcium (P < 0.01) and magnesium (P < 0.01). The soybean oil-fed calves exhibited poor bone development and a high incidence of abnormal hearts.