Sonographic monitoring of early follicle growth induced by melatonin implants in camels and the subsequent fertility

Abstract

The present study examined the effect of melatonin implants on follicle growth in dromedary camels two months ahead of their natural breeding season (December to March). Female camels (n Z 6) were treated with melatonin implants at the dose rate of 1 implant per 28 kg body weight sc. Control camels (n Z 6) were administered an SC placebo implant of 8 ml vitamin A. Ovarian ultrasonography was performed at weekly interval upto 7 weeks. Camels were mated with virile stud when a follicle (!10 mm) was visible on either of the ovaries. Blood was collected on day 7, 9, 15, 20, 25 and 30 for assay of plasma progesterone and sonography performed at the same time. Small follicles (2-3 mm) appeared around the periphery of ovaries in 83.3% of camels by day 7 and in 100% camels by day 14. By the end of 7th week an ovulatory size follicle (!1.0 cm) could be observed in 83.3% of treated camels, and these camels were mated with virile studs. In control group, small follicles appeared at the periphery of ovaries only in 66.6% camels but did not progress in growth except in one camel (16.6%) however, ovulating size (!10 mm) follicle was not observed in any camel by the end of 7th week. All treated camels ovulated and one treated camel became pregnant while early embryonic death occurred in one camel. Nonepregnant camels of both groups were mated during the breeding season. All camels of treatment group and 33.33% camels of control group became pregnant by the end of breeding season (April 2010). It was concluded that melatonin implants can augment the follicle growth in lactating camels ahead of the breeding season and pregnancy can occur on mating. Fertility of treated camels during the breeding season is improved.Sommario Nel presente studio viene esaminato l'effetto di impianti di melatonina sulla crescita del follicolo in dromedari -cammelli, nei due mesi precedenti il loro periodo di * Corresponding author.E-mail address: gnpobs@gmail.com (G.N. Purohit). , 25 e 30 giorno, per il dosaggio del progesterone plasmatico e l'ecografia eseguita allo stesso tempo. Follicoli piccoli (2-3 mm) sono apparsi nella periferia delle ovaie nel 83,3% dei cammelli al 7 giorno e nel 100% dei cammelli al 14 giorno. Entro la fine della VII settimana un follicolo ovulatorio di una certa dimensione (! 1,0 cm) è stato osservato nel 83,3% dei cammelli trattati, e questi cammelli sono stati fatti accoppiare. Nel gruppo di controllo, sono apparsi piccoli follicoli alla periferia delle ovaie solo nel 66,6% dei cammelli, ma senza progresso nella crescita, fatta eccezione per un cammello (16,6%), tuttavia, la dimensione di un follicolo ovulatorio (! 10 mm) non è stata osservata in nessun cammello, entro la fine della VII settimana. Tutti i cammelli trattati hanno avuto un'ovulazione e un cammello è rimasto incinta, mentre è avvenuta la morte precoce di un embrione in un altro cammello. I cammelli non gravidi di entrambi i gruppi sono stati accoppiati durante la stagione riproduttiva. Tutti i cammelli del gruppo di trattamento e 33,33% dei cammell...

Role of Melatonin in Reproductive Seasonality in Buffaloes

“…Administration of exogenous slow-release melatonin induced the restoration of the ovarian activity in summer anestrus buffaloes, which can be explained by a 'cascading effect' of at least a 10-fold increase on the plasma concentrations of GnRH and gonadotrophins, which provides the necessary boost for follicular growth and ovulation [50]. It has been shown that treatments with melatonin implants tend to originate an increase in serum melatonin concentration (9.10 pg/ml) in anestrus buffalo heifers [12] and in anestrus lactating buffalo (6.80 pg/ml) ( Table 1), which could be associated with the antiprolactinic action of melatonin, as it was suggested in another species [55].…”

Peripheral Reproductive Organ Health and Melatonin: Ready for Prime Time

“…Continual-release subcutaneous melatonin implants have also been found to advance ovarian follicular development in vivo in dromedary camels [103]. In this study, follicular size was monitored using ultrasonography.…”

Supplementation of Slow‐Release Melatonin Improves Recovery of Ovarian Cyclicity and Conception in Summer Anoestrous Buffaloes (Bubalus bubalis)

“…On the other hand, in camel, another short‐day breeder, action of melatonin in advancement of breeding season during summer could probably be due to its antiprolactin action (Dholpuria et al. ). Prolactin hormone is an important endocrinological factor responsible for summer anoestrus (Das and Khan ); therefore, similar mechanism may also occur in initiation of ovarian activity in summer anoestrous buffaloes following melatonin administration.…”

“…Nevertheless, the impact of exogenous melatonin on circulating concentrations and the subsequent alterations in the gonadotrophin pulse frequency and amplitude responsible for ovulation is yet to be investigated in summer anoestrous buffaloes. On the other hand, in camel, another short-day breeder, action of melatonin in advancement of breeding season during summer could probably be due to its antiprolactin action (Dholpuria et al 2012). Prolactin hormone is an important endocrinological factor responsible for summer anoestrus (Das and Khan 2010); therefore, similar mechanism may also occur in initiation of ovarian activity in summer anoestrous buffaloes following melatonin administration.…”