Effects of sodium bicarbonate, magnesium oxide and dried sugar beet pulp in diets of dairy cows on milk yield, milk composition and rumen fluid and some blood parameters

Abstract

The objective of this study was to evaluate the effect of buffering agent (NaHCO3 and MgO) or substituting Dried Sugar Beet Pulp (DSBP) with barley on milk yield, composition of milk, some blood parameters and ruminal fermentation in cows. In the experiment, four lactating Holstem cows with similar age, lactation period and milk yield were utilized. Cows with second phase of lactation were selected. Treatments consisted of control (40% Barley), control+1 % NaHCO3 (NaHCO3), control+1 % NaHCO3+0,5% MgO (MgO) and barley substituted with DSBP. All diets were calculated to be isocaloric and iso-nitogeneous. The experiment was a 4×4 Latin square design. While milk yield was significantly higher in animals fed diets containing NaHCO3+MgO compared with animals fed control, compositions of milk were not significantly different among the groups. Addition of NaHCO3, NaHCO3+ MgO significantly increased (p<0.05) acetic acid concentrations but did not affect blood parameters. In conclusion addition of NaHCO3 or NaHCO3 + MgO increased milk yield but did not affect composition of milk. An increase m ruminal acetic acid concentrations and acetic/propiomc acid ratio due to buffering agent is an important finding. It must be revaluated the use of supplements in feeding diets since they decrease propionic acid level. © Medwell Journals, 2010.