AGRICULTURAL RESEARCH COMMUNICATION CENTRE www.arccjournals.com/www.ijaronline.in *Corresponding author’s e-mail: anitaganguly@gmail.com 1 Division of Animal Genetics, National Bureau of Animal Genetic Resources, Karnal, Haryana, India. 2 Disease Investigation Laboratory, Krishi Vigyan Kendra, Ambala, LUVAS, Haryana, India. Indian J. Anim. Res., 51 (1) 2017 : 141-145 Print ISSN:0367-6722 / Online ISSN:0976-0555 Direct blood PCR detection of Babesia bigemina and its effect on haematological and biochemical profile in crossbred cattle of eastern Haryana Anita Ganguly*, R. S. Bisla, Indrajit Ganguly 1 , Harpreet Singh,Vandna Bhanot 2 and S. S. Chaudhri Teaching Veterinary Clinical Complex, Lala Lajpat Rai University of Veterinary and Animal Sciences, Regional Centre, Karnal-132 001, India. Received: 01-04-2016 Accepted: 19-07-2016 DOI: 10.18805/ijar.v0iOF.7007 ABSTRACT The present study aimed to diagnose Babesia bigemina in naturally infected crossbred cows and to determine its effect on haemato-biochemical profile of host animals. Blood samples from lactating crossbred cows (n=30) between 3-6 years of age and showing clinical signs of babesiosis were collected, with or without anticoagulant, and analyzed for the protozoa by direct smear, direct blood PCR detection of the apical membrane antigen 1 (AMA-1) gene specific amplicon of B. bigemina and estimation of haematological and biochemical parameters. Healthy crossbred cows (n=10), examined free from haemoprotozoan infections were included as control. Blood Direct PCR revealed a 448-bp amplified fragment. Out of 150 random blood samples screened, (27/150) 18% were positive under light microscope, whereas direct blood PCR revealed (39/150) 26% samples positive for B. bigemina. The result shows higher specificity and sensitivity of PCR test over blood smear examination. The infected group showed significantly (p<0.001) decreased levels of TEC (3.04±0.19), Hb (4.78±0.27) and PCV (14.53 ±0.87) than healthy control animals. However, differences in the red blood cell indices (MCV, MCH and MCHC) were non-significant (p>0.05) between the groups indicating normocytic hypochromic anaemia in affected crossbred cattle. Serum samples of infected cows showed significantly (p<0.01) higher values of ALT (78.83±8.95), AST (146.13±7.62), BUN (27.09±1.02), creatinine (1.93±0.1) and TBIL (1.42±0.06) than that of healthy control. A significant decrease (p<0.01) of TSP (6.12±0.13) and albumin (2.39±0.09) was also recorded in the infected cows compare to healthy control. The standardized blood direct PCR method of the present investigation may be useful for rapid and reliable diagnosis of B. bigemina in conjunction with microscopic examination. Moreover, marked changes in haematological and serum biochemical profile observed in B. bigemina infected crossbred cows may be useful in understanding disease pathogenesis and undertaking necessary corrective measures. Key words: AMA-1, Babesiosis, Boophilus microplus, Haematology, Serum biochemistry. INTRODUCTION The tick-borne disease babesiosis causes significant morbidity and mortality in cattle worldwide. Protozoan parasites Babesia bovis and B. bigemina, causative agents of cattle babesiosis, are transmitted by Ixodid ticks Boophilus microplus which is wide spread in many tropics and subtropics (O.I.E., 2005). Babesiosis results in considerable adverse economic impact on cattle industry particularly in developing countries including India (McLeod and Kristjanson, 1999). Infections are characterized by high fever, anorexia and dark brown urine (Yeruham et al., 2003). Although cattle infected with parasites are easily detectable during acute infections, however; detection becomes difficult in carrier cattle/chronic infections due to low number of parasites in peripheral blood. Accurate and early diagnosis of babesiosis, especially low-level infections, is important for better management, effective disease control, overcoming economic loss as well as in epidemiological studies (Fahrimal et al., 1992). Although serological methods are widely employed in determining sub-clinical infections; however they suffer from specificity and sensitivity (Durrani et. al., 2006; Col and Uslu, 2007; Mahmoud and Abou-Zeina, 2008; Terkawi et. al., 2011; Iseki et. al., 2010). On the contrary, PCR based technique has been proven to be very sensitive in detecting B. bovis and B. bigemina infected carrier cattle (Calder, 1996; Salem et al ., 1999; Guido et al ., 2002, Mosqueda et al., 2012). The present study was aimed at rapid diagnosis of Babesia bigemina in naturally infected crossbred cows and to determine its effect on haemato- biochemical profile of host animals. MATERIALS AND METHODS In the present study, necessary ethical approval was obtained from the Research Review Committee of Lala Lajpat Rai University of Veterinary and Animal Sciences (LUVAS), Haryana. Lactating crossbred cows (3-6 years) brought to outpatient department (OPD) of LUVAS Regional