The Effect of Royal Jelly and/or Equine Chorionic Gonadotropin on Reproductive Responses of Seasonally Anestrous Awassi Ewes Induced to Estrus Using Progesterone

The objective of this study is to evaluate the effects of Royal Jelly (RJ) and/or equine Chorionic Gonadotropin (eCG) on the reproductive responses of ewes that are out-of-season to estrus using progesterone (P4)-releasing devices (CIDR-G). Forty Awassi ewes were randomly allocated in equal numbers to four groups and were administered intravaginally with CIDR-G for 12 days and were treated with: 1) RJ (received a total of 4.8 g RJ given intramuscularly (i.m.) in 12 equal doses in conjunction with the 12-day P4 treatment), 2) eCG (received an i.m. injection of 500 IU eCG each at the time of CIDR-G removal) , 3) RJ- induced eCG (received a combination of both treatments) or 4) neither RJ nor eCG (Control group). At the time of CIDR-G removal (day 0), ewes were exposed to four rams and checked for breeding marks at 6-h intervals for 4 days. Accordingly, blood samples were collected to compare plasma P4 concentrations between RJ-treated and non-RJ-treated ewes, and for pregnancy diagnosis. The incidence and duration of estrus were not influenced (P 0.1) by either RJ or eCG or their combination and it averaged 82% and 20.6 ± 0.8 h, respectively. Intervals from the time of CIDR-G removal to onset of estrus were shorter (P 0.01) in RJ-treated, eCG-treated and RJ-eCG-treated than ewes in the control group. Royal Jelly treatment resulted in a greater (P 0.01) rate of decline in P4 and lower concentrations between days −10 and 0. None of the treatments affected overall pregnancy (36%) and lambing (33%) rates. In conclusion, RJ and/or eCG treatments were equally effective in shortening the intervals to the onset of estrus. The reduced pregnancy and lambing rates in all groups were primarily attributed to the use of inexperienced rams in fat tail-raising