Abstract: The effect of different Effective Rumen Degradable Protein (ERDP) to Fermentable Metabolizable Energy (FME) on early lactating cow responses was investigated. Total tract digestibility of organic matter of various feedstuffs including barely grain, corn grain, wheat bran, cottonseed meal, soybean meal, sugar beet pulp, alfalfa hay, cotton seeds, corn silage and fish meal was determined using in situ technique. These data were used to predict FME of the feedstuffs. Two diets were provided with different ERDP/FME ratio (9.7 and 10.7 g MJ 1). The diets fed to fourteen early lactating Holstein cows averaging 21±16 Days In Milk (DIM) and 32±9 Kg d 1 milk yield for seven weeks, using a completely randomized design. Dry matter intake, milk yield and milk composition were measured weekly. Blood metabolites including glucose and urea nitrogen were measured in weeks 4 and 7. Rumen fluid NH3-N was recorded in the 3rd week of the experiment. Dry matter intake was significantly (p< 0.05) lower for cows fed diet with ERDP/FME = 9.7 g MJ 1 than those fed ERDP/FME = 10.7 g MJ 1 (21 vs. 21.6, respectively). Milk yield was significantly (p< 0.05) higher in cows fed ERDP/FME = 9.7 g MJ 1 compared with those fed ERDP/FME = 10.7 g MJ 1 (35.2 vs. 32.3, respectively). Milk composition, blood metabolites and rumen fluid NH3-N were not significantly affected by the treatments (p>0.05).
F. Rezaii , M. Danesh Mesgaran , A.R. Heravi Moussavi and M.H. Fathi Nasri , 2007. Effect of Diets Containing Different Ratio of Effective Rumen Degradable Protein to Fermentable Metabolizable Energy on Early Lactating Holstein Cow Responses . Journal of Animal and Veterinary Advances, 6: 563-568.