Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8426088 | Theriogenology | 2018 | 38 Pages |
Abstract
This study aimed to evaluate the effects of melatonin implants on the reproductive performances and hormone levels of dromedary (Camelus dromedarius) bulls during the non-breeding and subsequent breeding seasons. Fourteen mature dromedary bulls were divided into a control group (nâ¯=â¯7) and a group that was implanted with melatonin (nâ¯=â¯7) twice, at the beginning of the study and 35 days later. The trial started on the 17th June and continued for 10 weeks during the non-breeding season. Reproductive performances of animals in the control and melatonin groups were evaluated weekly during the non-breeding season [control non-breeding (CNB) and melatonin non-breeding (MNB) groups, respectively] and evaluated again during the subsequent breeding season [control breeding (CB) and melatonin breeding (MB) groups, respectively], which started on the 6th December and continued for 10 weeks. MNB bulls had greater (Pâ¯â¤â¯0.05) scrotum circumference and testicular volume, sexual desire, reaction time and mating ability scores, and serum melatonin and testosterone concentration values (24.91â¯Â±â¯0.26â¯cm, 271.00â¯Â±â¯7.81â¯cm3, 2.31â¯Â±â¯0.13, 2.03â¯Â±â¯0.22, 2.26â¯Â±â¯0.09, 23.90â¯Â±â¯0.05â¯pg/mL and 2764.51â¯Â±â¯137.02â¯pg/mL, respectively) than the CNB group (23.63â¯Â±â¯0.05â¯cm, 199.21â¯Â±â¯3.27â¯cm3, 1.00â¯Â±â¯0.00, 0.00â¯Â±â¯0.00, 1.00â¯Â±â¯0.00, 9.46â¯Â±â¯0.08â¯pg/mL and 1872.41â¯Â±â¯264.89â¯pg/mL, respectively). The scrotum and testes, reaction time score, proportion of bulls refusing to mount, and serum melatonin values were significantly higher in MB than CB bulls (Pâ¯â¤â¯0.05). Progressive motility (PM), average pathway velocity, straight-line velocity, curvilinear velocity (VCL), linearity, straightness (STR), wobble, beat cross frequency (BCF), livability, and DNA integrity were significantly higher in MB than CB bulls (Pâ¯â¤â¯0.05). PM, VCL, STR, amplitude of lateral head displacement, BCF, and livability were significantly higher in MNB than CB bulls (Pâ¯â¤â¯0.05). In conclusion, melatonin implants improved the reproductive performance of bulls during the non-breeding and subsequent breeding seasons.
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Authors
Ayman Abdel-Aziz Swelum, Islam M. Saadeldin, Hani Ba-Awadh, Abdullah N. Alowaimer,