The onset of puberty in Blanca Celtiberica goat was evaluated in 34 autum‑born female kids by plasma progesterone determinations and oestrus behaviour from 6 to 11 months of age.
Twenty-six kids attained puberty for the study period. An 80.8% of cyclic animals had a first cycle of normal duration (20.6 days) with oestrus behaviour at first ovulation for the majority of kids. A 15.4% of cyclic kids showed an initial ovarian cycle of short duration (8.7 days between two consecutive oestrus) before a normal oestral cycle.
Mean liveweight or cyclic goals at puberty (28.3 ± 0.59 kg LW) was significantly higher (p<0.001) than that of the animals that did not attained puberty by the end of the study (22.2 ± 0.91 kg LW). Liveweight overlapping of the two populations suggests that a minimum 24.4 ± 0.51 kg body weight, with a 95% confidence interval, is required to Blanca Celtibérica goats to reach puberty. Puberty was reached at 10 months (306 ± 1.5 days) of age in autumn, when adult goal are in breeding season. These results suggest a body size‑photoperiod interaction in Blanca Celtibérica goats to attain puberty and this interdependence provides management advantages to prevent precocious pregnancies in autumn‑born kids at the next spring mating.