The effect of suplemental feeding on the reproductive behavior of Canchim young bulls. I. Pubertal traits

Abstract

The objective of this work was to evaluate the effect of supplemental feeding during the dry period on the onset of puberty in Canchim young bulls. Thirty weaned male calves were randomly alloted to the following treatments: T₁ - control, on Brachiaria decumbens pasture; T₂ - pasture plus 1.0 kg/an./day of a balanced concentrate; and T₃ - pasture plus 2.0 kg/an./day of concentrate. On the second dry period (year 2) the amounts of concentrate of T₂ and T₃ were increased to 2.0 and 4.0 kg/an./day. The results indicated that, even though the supplemented animals put on more weight during the dry season, treatments showed no effects on the traits studied. The means for weights and ages obtained were: 210.6 kg and 383.4 days for the first sperm; 216.9 kg and 401.3 days for the first motile sperm; 233.9 kg and 462.0 days for the onset of puberty; and 278.9 kg and 615.2 days for the sheath-penis detachment. The means obtained for the scrotal circunference were, 21.37 cm, 22.21 cm, 24.22 cm and 27.00 cm, respectively at 383.4, 401.3, 462.0 and 615.2 days of age.