Fig. 1
Body growth and testicular development of Yiling goat. a Fitting of testicular growth. The model for testicular growth was Wt = 44.5529/(1 + 440.4 × e− 0.0512d). Wt represents testicular weight, and d represents the number of days postpartum (dpp). The age of inflection point was 118.9 dpp. b Fitting of body growth. The model for body growth was Wb = 13.7439/(1 + 4.5074 × e− 0.0208d). Wb represents body weight, and d represents the dpp. The age of inflection point was 110 dpp. c Body weight and testicular weight of Yiling goat. Mean ± SE; means with different letters are significantly different among ages (P < 0.05). d, e, f Light micrographs of the testis in the Yiling goats at 60 dpp (D, D60), 90 dpp (E, D90) and 120 dpp (F, D120). At 60 dpp (D, D60), no spermatozoa were observed in the seminiferous tubules. At 90 dpp (E, D90), spermatocytes (arrowheads) were observed in the seminiferous tubules. After 90 dpp (F, D120), seminiferous tubules developed larger and many spermatozoa (square area) were seen constantly. HE staining, magnification 40×. Bar indicates 50 μm