Contents lists available at ScienceDirect Animal Reproduction Science journal homepage: www.elsevier.com/locate/anireprosci Mastitis outcomes on pre-ovulatory follicle diameter, estradiol concentrations, subsequent luteal profiles and conception rate in Buffaloes Mohamed Mohsen Mansour a, ⁎ , Moustafa M. Zeitoun b , Fekry M. Hussein c a Department of Animal and Poultry Production, Faculty of Agriculture, Damanhour University, Damanhour, Al-Behirra, Egypt b Department of Animal Production and Breeding, College of Agriculture and Veterinary Medicine, Qassim University, Buriedah, Saudi Arabia c Department of Theriogenology, Faculty of Veterinary Medicine, Alexandria University, Alexandria, Egypt ARTICLE INFO Keywords: Pre-ovulatory follicle Subclinical mastitis Clinical mastitis Luteal profile Conception rate Buffalo Estradiol ABSTRACT The objectives of this study was to investigate the outcome of mastitis, in its clinical or subclinical forms, on the mean diameter of pre-ovulatory follicle (POF), plasma estradiol concentration on the day of estrus, subsequent luteal profile and subsequent conception rate in buffaloes. Sixty dairy buffalo (Bubalus bubalus) conducted in this study were divided into three groups {healthy (H), n = 20; subclinical mastitis (SCM), n = 18; and clinical mastitis (CM), n = 22}. Ultrasonography of ovaries revealed that mean diameter of POF was larger (P < 0.05) in H buffalo (14.35 mm) compared to SCM (12.40 mm) and CM (10.25 mm). Also, plasma estradiol concentration on the day of estrus was higher (P < 0.05) in H buffalo compared to SCM and CM counterparts; 34.95 vs. 32.87 and 27.50 pg/ml, respectively. Besides, positive correlation was observed between the POF diameter with plasma estradiol concentration in H, SCM and CM buffaloes (r = 0.64, 0.74, 0.72 respectively, P < 0.05). Moreover, positive correlations (P < 0.01) were found on days 9, 12, 16, and 21 post-ovulation between POF diameter and luteal profile. Thus, the conception rate in H buffalo was higher (P < 0.05) compared with SCM and CM counterparts; 55% vs. 38.89 and 18.18%, respectively. In conclusion, mastitis in its clinical or subclinical forms disrupts the functioning of the pre-ovulatory follicle on the day of estrus, associated with low follicular estradiol production, resulting in suppression to subsequent luteal profile leading to substantial decrease in pregnancy consequence of buffaloes. 1. Introduction Buffaloes are the main dairy animals in some developing countries worldwide, supplying about 12% of world milk production. Despite this species tends to have relatively slow rate of reproduction and more reproductive problems such as inactive ovaries, long calving intervals and mastitis (Abd El-Razika et al., 2010). Mastitis is one of the most significant health problems of dairy herds as it cause physical, chemical and bacteriological changes in the milk of dairy buffaloes resulting in inferior quality and quantity of produced milk (Guccione et al., 2014, 2016a; Sharma et al., 2007). Somatic cell count (SCC) is usually used as indicator of inflammation to diagnose mastitis (Dhakal et al., 1992; Singh and Ludri, 2001; Moroni et al., 2006). According to several studies in buffaloes, quarters producing milk with an SCC below the threshold of 200 × 10 3 cells/mL and associated with negative bacteriological cultures (BC) are considered free from intramammary infections http://dx.doi.org/10.1016/j.anireprosci.2017.04.004 Received 11 December 2016; Received in revised form 9 April 2017; Accepted 11 April 2017 ⁎ Corresponding author. E-mail address: mohamedmohsen79@yahoo.com (M.M. Mansour). Animal Reproduction Science 181 (2017) 159–166 Available online 14 April 2017 0378-4320/ © 2017 Elsevier B.V. All rights reserved. MARK