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Abstract: This experiment was conducted to determine if feed supplementation before exposure of anoestrous does to males increases ovulation rate. Does (n =50) grazing natural vegetation were divided into two groups (n =25). One group received no feed supplementation, while the other was supplemented daily, with a mixture of 950g of alfalfa hay, 290g of rolled corn and 140g of soy bean per animal for 7 days before exposure to bucks. On April 7, all females were exposed to four adult sexually active bucks (two per group) for 15 days. The ovulation rate at the ovulation detected within 5 days of exposure to males, assessed by transrectal ultrasonography, was greater (P <0.05) in supplemented (1.6±0.2) than in non-supplemented females (1.0±0.2). In contrast, ovulation rate at the subsequent ovulation, detected between days 6 and 15 of contact with males, was not different (P >0.05) between supplemented (1.3±0.1) and non-supplemented females (1.3±0.2). Feed supplementation 7 days before exposure to sexually active bucks of females managed under grazing conditions increased their ovulation rate at the first male-induced ovulation but the stimulatory effect of supplementation did not persist and was not observed at the subsequent ovulation. [Copyright &y& Elsevier]

Abstract: Bucks rendered sexually active by a photoperiod treatment of long days can induce fertile ovulation in a group of goats with only 4h of contact daily with a male:female ratio of 1:10. Here we tested whether such bucks could induce fertile ovulations when stimulating successively three different groups of anovulatory goats when interacting 4h per day during 15 consecutive days. Control males (n =3) were introduced in the control group (n =25) of does at 8:00h and were removed at 12:00h. Experimental males (n =3) were in contact with the experimental groups of does: from 8:00h to 12:00h with a first group (n =27), from 12:00h to 16:00h with a second group (n =26) and with a third one (n =27) from 16:00h to 20:00h. Bucks were then placed until next day in another pen. Both in the control and the experimental groups, more than 85% of females ovulated, and the proportions did not differ between the control and experimental groups (P ≥0.67) or between the three experimental groups (P ≥0.67). Moreover, the ovulation rate did not differ significantly between the control and the experimental females nor between the three experimental groups. Bucks were able to fertilize more than 72% of does independently of the number of females they were exposed to (P ≥0.17). Finally, more than 58% of females kidded and fertility did not differ between the control and experimental groups (P =1) nor among experimental groups (P ≥0.77). We conclude that sexually active bucks are able to induce fertile ovulation in three successive groups of anovulatory goats even when the period of contact between sexes is reduced to 4h per day. [Copyright &y& Elsevier]