Effect of lipids in milk replacers on calf performance and lipids in blood plasma, liver, and perirenal fat.

Various fats (20% of dry matter) were fed in milk replacer to calves, from 3 to 31 d of age, to compare their effect on calf performance, feed efficiency, and lipids in blood plasma, liver, and perirenal fat. Dietary fats tested were tallow (control), canola oil, canola soapstocks, corn oil, reclaimed restaurant cooking fat, and a high phospholipid waste product. Corn oil plus tallow (1:1) diet promoted scours and poor calf gains, but canola oil diet, despite a high content of unsaturated fatty acids, gave excellent calf performance and feed utilization and no scours. Canola soapstocks plus tallow (1:1) and restaurant waste cooking fat lowered gains by 25 and 15% and reduced diet intake. Calves effectively utilized high phospholipid (23%) in dietary lipids. Main lipid classes in blood plasma were cholesterol esters and phosphatidylcholine, and in liver phosphatidylethanolamine and phosphatidylcholine. Fatty acid composition of the major blood plasma and liver lipids, and of perirenal fat, tended to reflect dietary fatty acid concentrations.