The effect of feed supplementation on the onset of puberty in Brazilian dairy heifers

Efeito da suplementação alimentar no início da puberdade em novilhas brasileiras

Most Brazilian dairy production is conducted by small holders whose general management skills and feeding programs are often deficient. One common problem directly attributed to underfeeding is that heifers rarely reach sexual maturity before 15 months of age. Groups of growing heifers were treated to detect the effects of protein supplementation and antihelmintic treatment on sexual maturity. The first ovulation occurred at 513 ± 44 and 573 ± 36 days (P<.01) in supplemented and control groups, respectively. Liveweight gains from start of the trial to the first ovulation were 378 ±.02 and 331 ±.04 g for suplemented (S) and control (C) groups. Only 52.17 % of heifers in C group (11 of 23) but 95.65 % in S group (22 of 23) reached sexual maturity before the age of 18 mo (P< .01). Animals with anthelmintic treatment had better growth performance than the controls.

heifers; puberty; protein supplementation; antihelmintic

São Paulo - Escola Superior de Agricultura "Luiz de Queiroz" USP/ESALQ - Scientia Agricola, Av. Pádua Dias, 11, 13418-900 Piracicaba SP Brazil, Tel.: +55 19 3429-4401 / 3429-4486, Fax: +55 19 3429-4401 - Piracicaba - SP - Brazil