The Effect of Partial Replacing Solvent Soybean Meal with Poultry Blood Meal on Performance and Metabolic Status of Fresh Holstein Dairy Cows

The objective of this study was to investigate the effect of replacing solvent soybean meal (SSBM) with poultry blood meal (PBM) on performance, metabolic status, and apparent digestibility of nutrients in Hol-stein fresh cows. Twenty-four Holstein cows (body weight (BW)±SD; 669.5±42.59 kg) were blocked by body condition score (BCS) at calving and previous lactation milk yield and randomly assigned to 1 of 3 experimental diets from calving until 21 days in milk (DIM): diet without PBM (0PBM), replacing 2.5% DMSSBM with PBM (2.5PBM), and replacing 5% DMSSBM with PBM (5PBM). There were no signifi-cant effects (P0.10) of treatments on dry matter intake (DMI), milk yield, and milk composition, but cows fed the 2.5PBM diets had significantly higher milk urea nitrogen (MUN) levels than cows fed the 0PBM and 5PBM diets (P0.01). Cows fed the 5PBM diet had significantly higher serum globulin, non-esterified fatty acids (NEFA), and β-hydroxybutyrate (BHB) and lower serum cholesterol concentrations than cows fed the 0PBM and 2.5PBM diets (P0.05). Blood urea nitrogen (BUN) concentration in cows fed the 2.5PBM diet was significantly (P=0.01) higher than cows fed the 0PBM and 5PBM diets. The apparent digestibility of dry matter in the 5PBM diet was significantly (P=0.03) lower compared to the 0PBM diet. However, there was no significant difference between the 5PBM and 2.5PBM diets. Overall, the lack of significant differences in performance, apparent digestibility of nutrients and serum metabolites between the 0PBM and 2.5PBM shows that the SSBM could replace up to 2.5% of DM with the PBM. However, levels higher than 2.5% of DM are not recommended due to low palatability and negative effects on the metabolic status of cows.