Monthly evaluation of blood hematological, biochemical, mineral, and enzyme parameters during the lactation period in Holstein dairy cows

• Published in: Comparative clinical pathology 2014-03, Vol.23 (2), p.275-281
• Main Authors: Nozad, Sh, Ramin, A. G., Moghaddam, Gh, Asri-Rezaei, S., Kalantary, L.
• Format: Article
• Language: English
• Subjects: Hematology; Medicine; Medicine & Public Health; Oncology; Original Article; Pathology
• ISSN: 1618-5641; 1618-565X
• DOI: 10.1007/s00580-012-1607-2

Concentrations of blood parameters and their interrelationships were investigated in dairy cows, during their lactation period, to determine the variations among parameters and the most reliable indices which could be useful for milk yield improvement. Blood was taken monthly during the 300 days of lactation and divided into early, mid, and late lactation. The highest monthly concentrations were observed on the fifth month of lactation for red blood cells (RBC), hemoglobin (Hb), calcium (Ca), potassium (K), sodium (Na), aminotransferase (AST), alkaline phosphatase (ALP), and packed cell volume (PCV) and the lowest were in the tenth month of lactation for blood urea nitrogen (BUN), cholesterol, hydroxybutyrate (BHB), Ca, K, Cl, and aminotransferase (AST). The maximum and minimum concentrations were found in early and late lactation, respectively. Mean comparison of parameter concentrations were significantly different among months and the three stages of lactation (with the exception of Hb and white blood cells). The most important correlations were between lymphocytes/neutrophils, Hb/PVC, RBC/PVC, Hb/RBC, AST/ALP, K/Na, triglycerides/Na, K/Ca, protein/Na, protein/Ca, triglycerides/cholesterol. Among these correlations, triglyceride, protein, and Na showed the strongest relationships and BHB, triglycerides, cholesterol, protein, BUN, Na, and ALP revealed the highest number of correlations with other parameters. In conclusion, blood parameter concentrations were different during the months and stages of lactation. The fifth month and mid-lactation for blood concentrations was a more reliable time than the other months and stages of lactation. Reliable relationships appeared between BUN, protein, triglyceride, Na, and BHB and could be applied as indices in supplementary studies related to the improvement of milk production in dairy herds.