Contents lists available at ScienceDirect Research in Veterinary Science journal homepage: www.elsevier.com/locate/rvsc Hematology reference intervals for neonatal Holstein calves Nikolaos Panousis a, ⁎ , Nektarios Siachos b , Georgios Kitkas a , Emmanouil Kalaitzakis a , Maria Kritsepi-Konstantinou c , Georgios E. Valergakis b a Clinic of Farm Animals, Faculty of Veterinary Medicine, School of Health Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece b Laboratory of Animal Husbandry, Faculty of Veterinary Medicine, School of Health Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece c Diagnostic Laboratory, Faculty of Veterinary Medicine, School of Health Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece ARTICLE INFO Keywords: ADVIA 120 Age Cattle CBC Gender ABSTRACT Data regarding hematologic reference intervals (RI) for neonatal calves have not been published yet. The aims of this study were: a) to establish hematology RIs for neonatal Holstein calves, b) to compare them with the RIs for lactating cows, and c) to investigate the relationship of age and gender with the hematologic profile of calves. Two-hundred and fifty-four clinically healthy Holstein calves (1–9 days old, from 30 farms) and 82 healthy Holstein cows (between 30 and 150 days in milk, from 10 farms) were blood sampled once for a complete blood count evaluation, using the ADVIA 120 hematology analyzer. An additional blood sample was collected from each calf for serum total protein concentration measurement. RIs and age-related RIs were calculated with the Reference Value Advisor freeware. Comparisons between calves and cows and between male and female calves were performed with t-test or Mann-Whitney test. Red blood cell count (RBC), white blood cell count (WBC), neutrophil, lymphocyte and platelet counts in calves were higher, while mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) were lower than in cows. Lymphocyte and platelets showed a notable increase through age. Finally, female calves had higher RBC, hematocrit and hemoglobin concentration than males. Age-specific RIs should be used for the interpretation of the complete blood count in Holstein calves. 1. Introduction The evaluation of the complete blood count (CBC) is, usually, the first ancillary aid for a practitioner, following clinical examination, to establish a diagnosis or to estimate a prognosis for a patient (Jones and Alison, 2007). Determining whether a parameter or a profile is within normality requires a comparison with reference intervals (RI) from a similar population of clinically healthy individuals. Therefore, RIs should be established considering differences in genotypes, age, gender, management and of course, analytical procedures (Friedrichs et al., 2012). The hematologic profile of calves has been investigated in the past, mostly in beef breeds (Raleigh and Wallace, 1962; Adams et al., 1992; Egli and Blum, 1998). Data for dairy breeds, and especially for Holstein calves, is limited. Tennant et al. (1974) reported hematologic values in 61 Jersey and 110 Holstein-Friesian calves from birth up to 6 months of age, using older analytical techniques. Mohri et al. (2007) reported age- related changes in 32 Iranian Holstein calves, repeatedly sampled every other week from birth up to 12 weeks of age, with an automated he- matology analyzer (Nihon Kohden, Cell Tac a, MEK 6108, Tokyo, Japan). Hematologic values for calves determined with the ADVIA 120 hematology analyzer, which is widely used nowadays, have been re- ported only for 15 Norwegian Red calves with repeated measurements from 1 week up to 6 months (weekly up to week 5 and thereafter monthly) (Brun-Hansen et al., 2006). Νone of the above studies was designed to focus specifically on the hematologic profile of Holstein calves during the crucial neonatal period, which is characterized by high morbidity and mortality due to congenital conditions, complications at parturition and, mainly, infec- tions (Mee, 2008). Published studies that reported comparisons between female and male calves are also limited. Raleigh and Wallace (1962) observed higher HGB and packed cell volume (PCV) values for Hereford female compared to male calves, while no differences between genders were found in Jersey and Holstein-Friesian calves (Tennant et al., 1974). The aims of this study were to: a) establish RIs for hematologic parameters of neonatal Holstein calves with the ADVIA 120 hematology analyzer, b) compare them with the RIs of adult Holstein cows, and c) determine the association of age and gender with the hematologic profile of calves. https://doi.org/10.1016/j.rvsc.2018.01.002 Received 30 September 2017; Received in revised form 28 November 2017; Accepted 8 January 2018 ⁎ Corresponding author. E-mail address: panousis@vet.auth.gr (N. Panousis). Research in Veterinary Science 118 (2018) 1–10 0034-5288/ © 2018 Elsevier Ltd. All rights reserved. T