Reprod Dom Anim. 2018;1–5. wileyonlinelibrary.com/journal/rda | 1 © 2018 Blackwell Verlag GmbH 1 | INTRODUCTION The use of foetal bovine serum (FBS) in reproductive technologies such as embryo culture and oocyte maturation has been extensively used (Goel, Goel, Bhatiya, & Kharche, 2016; González-Fernández, Macedo, Lopes, Rocha, & Macías-García, 2015; Leibfried-Rutledge, Critser, & First, 1986; Rehman, Collins, Suh, & Wright, 1994; Wang, Liu, Holyoak, & Bunch, 1997; Yang, Chen, & Li, 1999). However, supplementation of FBS in the incubation medium for sperm has been less frequent. Some results showed FBS on the sperm. Reyes- Moreno, Boilard, Sullivan, and Sirard (2002) observed that FBS did not significantly improve the motility of thawed bovine sperm, whereas Leibfried-Rutledge et al. (1986) found little effect of FBS on sperm in oocyte fertilization of hamster. In addition, González- Fernández et al. (2015) did not obtain fertilization by incubating sperm and equine oocytes in the presence of FBS. However, it has been recognized that the presence of FBS re- sults in higher motility in post-cryopreserved sperm increases the number of embryos and enhances the acrosome reaction in several species (Chen, Doncel, Alvarez, & Acosta, 1995; Dong, Huang, & Tiersch, 2006; Funahashi & Day, 1993a; Garzón et al., 2008; Goel et al., 2016; Karimi, Kamangar, Azadbakht, Amini, & Amiri, 2014; Keskintepe, Luvoni, Rzucidlo, & Brackett, 1996; Koh, Yokoi, Tsuji, Tsuchihashi, & Ohta, 2010; Kwon et al., 2014; Long et al., 1996; Rizal & Sangadji, 2013; Tian et al., 2014;). The use of FBS as an alternative supplement to bovine serum albu- min (BSA) has been previously observed (Chen et al., 1995; González- Fernández et al., 2015; Keskintepe et al., 1996; Leibfried-Rutledge et al., 1986). Although FBS has been used in sperm of some species such as human, bovine, porcine and goat, no research has been done on the incubation of South American camelids. In the present work, we study the effect of FBS on the motility, acrosome reaction and the binding ability of sperm to the zona pellucida in alpaca. 2 | MATERIALS AND METHODS 2.1 | Collection of samples and obtaining gametes The samples were obtained in the municipal slaughterhouse of Huancavelica. Testicles and ovaries of alpaca were collected, Received: 9 October 2017 | Accepted: 28 January 2018 DOI: 10.1111/rda.13159 ORIGINAL ARTICLE Effect of Foetal Bovine Serum on sperm motility, acrosome reaction and spermatic interaction to zona pellucida in alpacas (Vicugna pacos) Z Bravo | M Valdivia Laboratory of Animal Reproduction Physiology, Faculty of Biological Sciences, Universidad Nacional Mayor de San Marcos, Lima, Peru Correspondence Martha Valdivia, Laboratory of Animal Reproduction Physiology, Faculty of Biological Sciences, Universidad Nacional Mayor de San Marcos, Lima, Peru. Email: mvaldiviac@unmsm.edu.pe Contents The use of foetal bovine serum (FBS) in cell culture media is quite common. However, little is known about the effect of FBS on sperm. The severe difficulties in alpaca repro- duction demand the search of new methods for in vitro reproductive management. In the present study, we use for the first time FBS as a supplement in the culture medium for sperm in alpaca, and the effect of FBS on motility, acrosome reaction and sperm binding to the zona pellucida in this species was evaluated. A concentration of 10% v/v FBS was used. The sperm motility with FBS at the first hour was 32.8% (vs. control = 30.0%), whereas at the second hour sperm motility with FBS was 30.2% (vs. control = 28.8%). The acrosome reaction reached an average of 44.0% for treatment with FBS (vs. control = 30.1%). The sperm-zona pellucida binding assay showed that the samples incubated with FBS had an average of 2.7 bound sperm (vs. control = 1.7). Only a significant difference was observed for sperm motility at the first hour and for the acrosome reaction. It is concluded that FBS favours the capacitation of sperm in alpaca.