The objective of this trial was to evaluate the effect of supplementing dietswith similar protein, fiber and lipid contents with different lipid sourceson dry matter intake, milk yield and feed efficiency of early lactating Jerseycows. Eight multiparous cows averaging 420 kg of body weight and daily yieldof 20 kg of 3.5% fat corrected milk (FCM) were randomly assigned to two replicated4 x 4 Latin squares. Each experimental period lasted four weeks and means werecompared by F-test. Cows were fed the following diets: CON control diet withoutlipid supplementation; RPF- basal diet supplemented with a commercial rumen-protectedfat source (calcium salts of fatty acids from palm oil); RBRO- basal diet supplementedwith rice bran and rice oil; RBT- basal diet supplemented with rice bran andtallow. The concentrate portion of the diet contained ground corn and soybeanmeal while the forage portion was composed by corn silage and alfalfa hay (1:1,dry matter basis). Concentrate was fed three times a day and forage ad libitum.Diets were formulated to contain a forage:concentrate ratio of 55:45. Supplementationwith different dietary lipid sources did not affect dry matter intake but increasedmilk yield compared to the CON diet. In adittion, both FCM and feed efficiencywere greatest on cows fed the RPF diet.
