Journal of Agricultural Economics and Development Vol. 1(6), pp. 145-152, December 2012 ISSN 2327-3151 ©2012 Academe Research Journals

Full Length Research Paper

Impact of a short period-energy supplementation on the ovarian follicular dynamics, blood metabolites and sex hormones in ewes

G. Badry Mahmoud¹, Sh. M. Abdel-Raheem², W. Senosy³ and R.I. Derar³*

¹Animal Production Department, Faculty of Agriculture, Assiut University, Egypt.

²Department of Nutrition and Clinical Nutrition, Faculty of Veterinary Medicine, Assiut University, 71526 Assiut, Egypt.

³Department of Theriogenology, Faculty of Veterinary Medicine, Assiut University, 71526 Assiut, Egypt.

*Corresponding author. E-mail: derar40@yahoo.com; Tel: 02-88-2334699.

Accepted 17 December, 2012

Abstract

The effect of energy supplementation for a short period on follicuar turnover and estrogen concentration during the estrus cycle in subtorpics was studied in 13 ewes (7 ewes subjected to high energy, HEG and 6 as normal energy group, NEG). After ovulation (Day 0), a high-energy diet (10.87MJ ME/kg diet; 130 % of maintenance) was fed to HEG from Day 1 to Day 4 after ovulation and from Day 8 to Day 11 of the cycle (4 days each). The high-energy diet consisted of 850 g concentrate mixture and 150 g alfalfa hay, plus ad libitum access to wheat straw. The NEG was offered as maintenance diet throughout the experiment. Follicular development was observed ultrasonographically every other day while blood samples were collected daily throughout the experiment for the analysis of albumin, globulin, glucose, total cholesterol, urea, triglycerides, total proteins, estrogen and progesterone. Transient feeding of high-energy ration during early and mid luteal phase of estrous cycle significantly influenced the concentration of glucose and some metabolic profiles. A marked rise in the concentrations of glucose appeared in response to the intermittent nutritional stimulus. Mean plasma concentrations of glucose were significantly (P < 0.05) higher in the HEG than in the NEG on almost all days during treatment period. For ovarian performance, the total number of medium and large follicles that developed on the day prior to the 2nd ovulation in the HEG (3.5±0.17) was significantly higher than that of the NEG (1.87±0.26). Ovulation rate (2.8±1.0) in the HEG was significantly higher than that of the NEG (1.15±0.6). No significant difference was detected in the concentrations of progesterone and estrogen throughout the experiment between groups except for E2 peak concentration on Day 8. The present experiment demonstrated that short-term intermittent nutritional stimulus in cyclic ewes increased the total number of ovulatory follicles and the ovulation rate in association with increasing plasma concentrations of glucose and peak levels of estrogen.

Key words: Ewe, follicular dynamics, transient energy, P4, E2, blood metabolites.