title: Enhancement of the male effect on reproductive performance in female Mediterranean goats with long day and/or melatonin treatment.
abstract: The aim of this study was to determine whether the male effect on reproductive performance in female Mediterranean goats could be enhanced if used in combination with long day and/or melatonin treatments. Thirty-two does were exposed to long days (16 h of light/day) for 95 days. At the end of this period, 16 received one melatonin implant (group LD-M) and 16 did not (group LD). Simultaneously, 16 does under natural photoperiod were implanted with melatonin (group M) or given no treatment (group C, n=16). On April 14th, after 49 days of isolation from males, all does were exposed to bucks fitted with marking harnesses. Oestrous activity, as detected by visual observation, was recorded daily. Transrectal ultrasonography was used to record ovulation, and ovarian activity confirmed by determining plasma progesterone concentration. Oestrous activity, ovulation and fertility were greater in all treatment groups compared with group C (P<0.05), but no differences in ovulation rate or litter size were observed (P>0.05). Productivity (mean number of kids per female) of the LD-M and M groups was significantly greater than in group C (1.50 ± 0.01 and 1.37 ± 0.01 vs. 0.69 ± 0.01 kids, respectively) (P<0.05). Combining melatonin treatment with natural or artificial long days adds to the impact of the male effect.
authors.affiliation: Departamento de Ciencias Agroforestales, Universidad de Huelva, Campus de Excelencia Internacional Agroalimentario, ceiA3, Carretera de Palos de la Frontera s/n, 21819 Palos de la Frontera, Huelva, Spain. zarazaga@uhu.es
authors.forename: Luis A
authors.initials: LA
authors.lastname: Zarazaga
authors.forename: Irma
authors.initials: I
authors.lastname: Celi
authors.forename: José L
authors.initials: JL
authors.lastname: Guzmán
authors.forename: Benoît
authors.initials: B
authors.lastname: Malpaux
mesh_terms: D000818:Animals; D004343:Drug Implants; D005260:Female; D006041:Goats / Q000502:physiology*; D008098:Litter Size; D008297:Male; D008550:Melatonin / Q000008:administration & dosage / Q000494:pharmacology*; D010060:Ovulation / Q000187:drug effects / Q000502:physiology; D017440:Photoperiod; D011247:Pregnancy; D011374:Progesterone / Q000097:blood; D012098:Reproduction / Q000187:drug effects*; D012726:Sexual Behavior, Animal / Q000502:physiology*
chemical_list: D004343:Drug Implants; D011374:Progesterone; D008550:Melatonin