Evaluation of melatonin and bromocryptine administration in Spanish goats: I. Effects on the out of season breeding performance in spring, kidding rate and fleece weight of does

The demand for meat goats in the USA is increasing, particularly in the Christmas and Easter holiday season. Manipulation for spring breeding in goats could increase productivity of flocks, enhance profitability and elevate the supply of meat goats at a time when demand is high. Four Spanish bucks were conditioned for 2 months to long day photoperiod (16 h light:8 h dark), followed by a single melatonin implant (18 mg, 6-week release period). Eighty Spanish female goats (15 does and 65 doelings) were allotted to five treatments: control (C); melatonin implant (MI); melatonin and bromocryptine (225 mg, 60-days release period) implants (MIB); oral administration of melatonin (MO, 3 mg per day); and oral administration of melatonin and the bromocryptine implant (MOB). After the fifth week of melatonin administration, does were randomized and bred in three single-sire groups for a 35-days period. Melatonin administration elevated serum melatonin level ( P