Effect of the duration of visual exposure to the male on the reproductive performance of nulliparous guinea pigs.

With the aim of determining the optimal duration of visual male exposure on the reproductive performance of nulliparous guinea pigs (Cavia porcellus), this study evaluated key reproductive indicators from mating to parturition. Sixty 60-day-old females were distributed into three treatments: traditional continuous mating (T0), controlled mating with 14-day prior visual male exposure (T1), and controlled mating with 7-day prior visual male exposure (T2). Results showed that T1 significantly increased the frequency of first estrus between days 6 and 10 (67%; p = .02) compared to T0 and T2 (38%). Additionally, T1 showed the highest frequency of afternoon estrus (42%; p < .05) and a higher rate of estrus repetition (p < .05). Regarding reproductive efficiency, T0 and T2 females exhibited significantly fewer non-productive days (10.5 and 11.3 d, respectively) compared to T1 (17.0 d; p < .01). Conversely, the feed cost per female was lowest in T1 (7.23 PEN), followed by T2 (9.27 PEN) and T0 (10.05 PEN; p < .01). No significant differences were observed in litter size (p = .08) or litter weight (p = .23). In conclusion, while 14 days of visual biostimulation prior to mating optimizes estrus synchronization but increases reproductive failures, a 7-day exposure successfully reduces non-productive days and feed expenditure in nulliparous guinea pigs, improving the economic merit of the intensive system without compromising productive parameters.