The aim of this study was to investigate the influence of long-term high-protein
flushing on ovarian function and metabolic status in Ossimi ewes. Fourteen cycling
Ossimi ewes were divided into high protein (210 % of maintenance crude protein) or
treatment group (TG; n = 7) and control group (CG; n = 7). Oestrous was synchronized
by PGF2α, monitored ultrasonographically daily for two oestrous cycles. The CG fed a
maintenance diet (9.5 % CP) through-out the experiment. The mean number of small
(2–2.9 mm), medium (3–5 mm) ovarian follicles, and follicular waves were higher
(P<0.01) in ewes of TG compared to that of CG in the first and second oestrous. The
size of large, subordinate and ovulatory follicles were greater (p <0.05) in ewes of TG
compared to those of CG. Ewes of the TG recorded a higher (p <0.05) ovulation rate in
the first cycle while, ovulation rate did not show any significant change in second
oestrous. Long term flushing of high-protein ration significantly influenced the
concentration of glucose and some metabolic profiles. Concentration of serum total
proteins was greater at 0, 1 and 13 days, while serum total cholesterol was greater at
day 0 and 1 after first oestrous (ovulation is day 0) in ewes of TG as compared to ewes
of CG. Serum glucose was increased significantly (p<0.05) at day 3 and 13 after first
oestrous and at day 0 and 7 after second ovulation in TG when comparing to CG. There
was significant (p < 0.05) increase in serum concentrations of progesterone at day 13
after first oestrous in TG and at day 3 after second oestrous. The level of serum
estradiol 17-β increased significantly at day 0, 1, 3, 7 and 13 in the first oestrous and at
day 0 on second oestrous in TG as compared to CG. In conclusion, the long term
protein flushing increased the number of small and medium follicles and follicular
waves, the size of ovulatory follicles in the first and second oestrous, the reproductive
efficiency in subtropical ewes. Long term protein flushing increase ovulation rate in the
first but had no effect on the second oestrous.