The Efficiency of Melatonin Hormone Implantation in Suppressing the Estrus Cycle in Domesticated Queens (Felis catus)
Abstract The current study evaluated the efficiency of melatonin implants as a single dose subcutaneous to suppress or delay the estrus cycle in queens. The study was conducted in the animal house of the College of Veterinary Medicine, University of Baghdad, from 18/12/2022 to 1/5/2023. Ten domesticated cats of known origin aged between (1-3) years old were used, non-pregnant. The cats were divided randomly into two groups. The first group of (n=5) cats was left without treatment to the control group, and the second group of (n=5) cats was administered melatonin implants as a single-dose subcutaneous as a single dose as a treatment group. Before starting treatment at day zero, 3 ml of blood was collected from the jugular vein in all cats to measure estrogen and progesterone hormones. Post-treatment, the cats were monitored twice a day to determine the sexual behavior of estrus based on clinical signs, using a male detector and taking a swab from the vagina to confirm the estrus phase. Also, on days 14-30 and 60 after treatment, to study the effect of melatonin implants on the reproductive hormonal state (estrogen and progesterone). The results of the present study showed that they recorded 28.00 ± 8.38 days and 111.00±2.68 days in G1 and G2, respectively, with significant (p<0.05) related to G2 compared with G1. While there was a non-significant effect, only a numerical difference (P ≤ 0.5) in the treatment group's duration of the estrus phase was 7.00+ 0.70 for G1 compared to G2, recorded 9.20±1.11 days. The estrogen hormone in the treatment group is basal under 20 pg/ml compared with the control group, which shows different concentrations in different periods. There was no significant difference of (p<0.05) in the progesterone hormone in different periods, which was at a basal level under 2ng/ml. In conclusion, the melatonin implant 18mg suppresses the estrus cycle for 4 months without adverse effects and makes the concentration of estrogen and progesterone hormone at the basal level.