Effect of feeding greater amounts of dietary energy for ashort-term with or without eCG injection on reproductiveperformance, serum metabolites and hormones in ewes
Javad Habibizad, Ahmad Riasi, Hamid Kohram, Hamid Reza Rahmani
(Animal Reproduction Science. 160: 82-89)
This study was conducted to compare the effect of transient high-energy diet in a short-term period with or without eCG injection on ovarian follicle development, twining rate,serum metabolites and hormones in ewes. A total of 45 estrous cyclic Naeini ewes wererandomly assigned to three experimental groups: 1—Control (control), 2—High energyshort-term feeding (HE), and 3—high energy short-term feeding + eCG injection (HEe). Eweswere housed in individual pens with free access to feed and water. The stage of the estrouscycle of all ewes was synchronized by insertion of intravaginal progesterone sponges. Focusfeeding started from 4 days before until 1 day after sponge removal. Follicle developmentwas monitored from 4 days before until 1 day after sponge removal and blood samples weretaken during this time. Results showed that ewes fed high energy diets (HE and HEe) hadgreater (P < 0.05) large follicle numbers compared with the control group. Feeding highenergy diets increased (P < 0.05) serum glucose, cholesterol and insulin, but had lesser(P < 0.05) serum urea nitrogen concentrations near the time of ovulation. After the startof experiment, ewes fed high energy diets had less (P < 0.05) serum estradiol. However, 1day after sponge removal, serum estradiol in HE and HEe groups increased (P < 0.05). It wasconcluded that short-term (6-day) changes in amount of dietary energy with or withouteCG injection increased twin births and had beneficial effects on the blood metabolites andhormone concentrations in Naeini ewes.
Keywords: High energy, Focus short-term feeding, Folliculogenesis,Ovulation, Naeini ewes