Andrologia. 2017;e12904. wileyonlinelibrary.com/journal/and | 1 of 8 https://doi.org/10.1111/and.12904 © 2017 Blackwell Verlag GmbH Accepted: 29 July 2017 DOI: 10.1111/and.12904 ORIGINAL ARTICLE Infrared thermography as a noninvasive method to assess scrotal insulation on sperm production in beef bulls S. R. O. Menegassi 1 | G. R. Pereira 1,2 | E. A. Dias 3 | M. K. Rocha 1 | H. R. Carvalho 1 | C. Koetz Jr 2 | E. R. Oberst 4 | J. O. J. Barcellos 1 1 Department of Animal Science, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil 2 Department of Animal Production, University of Northern Parana, Arapongas, PR, Brazil 3 Biological Science Institute, Federal University of Rio Grande, São Lourenço, RS, Brazil 4 Department of Veterinary Clinical Pathology, Veterinary School, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil Correspondence Gabriel Ribas Pereira, University of Northern Parana, Department of Animal Production, Arapongas, PR, Brazil. Email: gabriel.pereira@ufrgs.br Funding information The Coordination for the Improvement of Higher Education Personnel/CAPES, Brazil, Grant/Award Number: Project CAPES/PNPD No. 2842/2010; Brazilian Council of Scientific and Technological Development, Grant/ Award Number: Project CNPq/Universal No. 456724/2014-1 Summary This study evaluated the thermoregulation and spermatogenic changes by scrotal temperature gradient using infrared thermography in testicular compromised bulls. Bulls were insulated (n = 6) for 72 hr and control animals (n = 3) remained without in- sulation during all the experimental period. Seminal evaluation was performed prior, at insult removal and once per week for 13 consecutive weeks. Mean temperature gradi- ent in insulated animals was lower at the time of insulation removal compared to the week prior and after the insult (p < .05). Two weeks after insult, sperm motility was lower in insulated compared to control animals (p < .01) and spermatozoa total defects were higher in insulated compared to control animals (p < .05). Two and seven weeks after insult, the major defects were higher in insulated compared to control animals (p < .05). Scrotal temperature gradient showed a positive correlation with sperm mass motion (p < .01) and a negative correlation with ocular globe temperature (p < .01) in insulated animals. The infrared thermography can be used to evaluate ocular globe temperature in bulls; however, it is only effective to detect changes in scrotal temperature gradient at the insult removal. KEYWORDS bulls, noninvasive technique, semen, testicular insulation, testicular thermoregulation 1 | INTRODUCTION Noninvasive methods using infrared thermography (IRT) are commonly used to assess physiological and metabolic parameters and its impact of environmental conditions on animal welfare (Kotrba, Knízˇková, Kunc, & Bartos, 2007; Montanholi et al., 2009; Stewart, Stafford, Dowling, Schaefer, & Webster, 2008). Since the 80s, IRT has been used as a noninvasive method to determine the temperature of the scrotal surface in bulls and to establish the pattern of temperature distribution in clinically normal bulls compared to bulls with testicular abnormalities (Coulter, Senger, & Bailey, 1988; Purohit et al., 1985). The application of this IRT technique to beef cattle reproductive eval- uation will provide further opportunities to evaluate scrotal surface temperature and to determine possible deleterious process involved in testicular tissues. In beef cattle breeding systems, mating takes place during the hottest months of the year and bulls are subject to environmental variations that may interfere with their fertility and herd reproduc- tive effectiveness (Berry, Evans, & Parland, 2011; Lunstra & Coulter, 1997). Nevertheless, the reproductive success is one of the most important factors affecting the profitability of the cow–calf system (McManus, Louvandini, Carneiro, Lima, & Neto, 2011; Menegassi, Barcellos, Lampert, Borges, & Peripolli, 2011). Perhaps, it is always recommended, before the beginning of the breeding season, to evaluate bulls by the breeding soundness examination (BSE) that is still the most accurate and economical approach to predict fertility