Oestrus and ovulatory response of goats with different parity to male effect and short-term progestagen treatment
Ficheiros
Data
2008
Autores
Simões, João
Azevedo, Jorge Manuel Teixeira de
Título da revista
ISSN da revista
Título do Volume
Editora
Resumo
The aim of this work was to determine the oestrous and ovulatory activity in goats with different parity after male effect associated to short-term progestagen treatments. In April, 15 nulliparous (NG; 25.2 ± 0.7 Kg) and 22 multiparous (MPG; 40.3 ± 0.7 Kg) Serrana goats were treated with 20 (NG20=7; MPG20=11), or 30 mg (NG30=8; MPG30=11) of fluorogestone acetate sponges (Chronogest® CR 20 mg / Chronogest® 30 mg, Intervet, Holland), starting 6 days before introduction of 3 active bucks in the flock (BI). Before treatment, all goats were anoestrous. Oestrous behaviour and mounting acceptance were evaluated, every 8 h, until 80 h after BI. Plasma LH levels were evaluated until 24h after onset of oestrus. Plasma progesterone (P4) was determined, twice weekly, from 2 months before until 10 days after BI. Sub-oestrus (silent ovulation) goats were considered when ovulation occurred without oestrous behaviour. No significative differences were found in percentage of oestrus and ovulatory activities between progestagen treatments (P > 0.05). Oestrous behaviour was observed in 26.7% (4/15) of NG and 68.2% (15/22; P = 0.01) in MPG. Sub-oestrus occurred in 53.3% (8/15) of NG and only in 13.6% (3/22; P < 0.01) of MPG. The percentage of ovulation was 90.9% (20/22) in NG and 80.0% (12/15; P > 0.05) in MPG. In conclusion, parity of females appears affect the oestrus behaviour response but not ovulation in goats exposed to male effect after progestagen treatments.
Descrição
Palavras-chave
Male effect , ovulation , Goats , Progestagen