Biomaterial Database

The effects of melatonin and light treatment on the reproductive performance of yearling Suffolk rams. 1991

M Hanif, and H L Williams

Royal Veterinary College, University of London, Potters Bar, Herts.

The effects of melatonin and light treatments on the reproductive performance of yearling Suffolk rams was investigated. One group (group A, n = 5) remained in the local light environment (lat. 51 degrees 43'N). The other two groups (group B, n = 5; group C, n = 5) were given a priming period of long days [18 h light (L):6 h dark (D)] during 26 January-9 March. During 9 March-16 October, group B was exposed to short days (9L:15D) and group C was given melatonin implants (Regulin) at 5-weekly intervals. Testis diameter, sexual behaviour and semen quality were used to assess reproductive performance. The responses of groups B and C were similar and peak reproductive performance occurred in these groups significantly earlier than in group A. Peak performance was not maintained in groups B and C throughout the short day and melatonin treatment periods and this has been attributed to refractoriness. The response of group C clearly indicates that melatonin treatment may be considered as an alternative to photostimulation for the preparation of rams for out-of-season breeding.

UI	MeSH Term	Description	Entries
D008027	Light	That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.	Light, Visible,Photoradiation,Radiation, Visible,Visible Radiation,Photoradiations,Radiations, Visible,Visible Light,Visible Radiations
D008297	Male		Males
D008550	Melatonin	A biogenic amine that is found in animals and plants. In mammals, melatonin is produced by the PINEAL GLAND. Its secretion increases in darkness and decreases during exposure to light. Melatonin is implicated in the regulation of SLEEP, mood, and REPRODUCTION. Melatonin is also an effective antioxidant.
D010507	Periodicity	The tendency of a phenomenon to recur at regular intervals; in biological systems, the recurrence of certain activities (including hormonal, cellular, neural) may be annual, seasonal, monthly, daily, or more frequently (ultradian).	Cyclicity,Rhythmicity,Biological Rhythms,Bioperiodicity,Biorhythms,Biological Rhythm,Bioperiodicities,Biorhythm,Cyclicities,Periodicities,Rhythm, Biological,Rhythmicities,Rhythms, Biological
D011897	Random Allocation	A process involving chance used in therapeutic trials or other research endeavor for allocating experimental subjects, human or animal, between treatment and control groups, or among treatment groups. It may also apply to experiments on inanimate objects.	Randomization,Allocation, Random
D012098	Reproduction	The total process by which organisms produce offspring. (Stedman, 25th ed)	Human Reproductive Index,Human Reproductive Indexes,Reproductive Period,Human Reproductive Indices,Index, Human Reproductive,Indexes, Human Reproductive,Indices, Human Reproductive,Period, Reproductive,Periods, Reproductive,Reproductive Index, Human,Reproductive Indices, Human,Reproductive Periods
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012756	Sheep	Any of the ruminant mammals with curved horns in the genus Ovis, family Bovidae. They possess lachrymal grooves and interdigital glands, which are absent in GOATS.	Ovis,Sheep, Dall,Dall Sheep,Ovis dalli