Impact of Dietary Fat Type and Amount on Growth Performance and Serum Cholesterol in Rabbits

Problem statement: Literature data on the effect of dietary fat on growth performance in rabbits are inconclusive. For commercial rabbit production it is relevant to know to what extent dietary fat level and type can be manipulated. In the present study serum cholesterol was also analyzed because its relation to the amount and type of dietary fat was not known for rabbits. Approach: Young growing rabbits were fed diets containing one of four different levels (5.2-41.8 energy %) of either coconut fat or corn oil. Fat was added to the diets at the expense of an isoenergetic amount of corn starch and dextrose in a 1:1 ratio. The diets were in pelleted form and supplied ad libitum. Results: Increasing fat intakes in the form of either coconut fat or corn oil enhanced weight gain and improved feed efficiency. The effect of coconut fat was maximal at 20.9 energy % (9.9%, w/w) and the greatest effect of corn oil was seen at an inclusion level of 41.8 energy % (20.2%, w/w). As would be expected, replacement of dietary corn oil by coconut fat significantly decreased serum cholesterol concentrations. The cholesterol-lowering effect of corn oil versus coconut fat increased markedly with higher dietary inclusion levels of fat. Conclusion: The addition of fat to the diet improved growth performance. It is suggested to find out whether the present observations can be applied in the formulation of diets for fryer rabbits. The new observation for rabbits is that the hypocholesterolemic response to corn oil increased with higher intake levels.