Description
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.
; Baril, Gérard 
