MUTHA RAO, M (Major)MOULI KRISHNA, KPADMAJA, KYEDUKONDALU, DUDDUKURI2016-12-022016-12-022015-11http://krishikosh.egranth.ac.in/handle/1/88930ABSTRACT : The aim of this research was to determine the effect of lower doses of FSH on superovulatory responses in Ongole (Bos indicus) cattle. Thirteen lactating /dry, multiparous, clinically normal, cyclic Ongole cows aged 6-14 years were administered NIH – FSH – P1 @ 100mg (Group I, n=7) and 130mg (Group II, n=6). In both groups superovulation was started on the 10th day of natural estrus cycle after confirming the presenceof CL. Embryos were collected non-surgically 7-7.5 days after super estrus and were morphologically evaluated based on stage of development and quality. A total of 92.30% cows responded to superovulation treatment without any significance difference between groups. Cows of group II produced non-significantly (P>0.05) higher ovarian response than those of group I. The mean number of total ova/embryo (1.83 ± 0.65 and 3.83 ± 1.72) and viable embryos recovered (1.00 ± 0.68 and 3.17 ± 1.30) in group I and group II respectively, did not differ significantly (P>0.05). The ovulation rate and embryo recovery were negatively correlated to concentrations of P4 on day 0 but positively correlated to P4 concentrations on day 7. The P4 concentrations were highest on day 7 after superestrus. In the present study, in general a substantial increase in the levels of oxidative stress factors like MDA and cortisol and antioxidant enzyme activities such as SOD and catalase, has been noticed on the day of embryo collection (day 7). The results of the present study reveal that lowering the dose of FSH to 100mg did not elicit satisfactory superovulatory response in Ongole cows as compared to 130mg. Further studies to assess the reasons for reduced ova/ embryo recovery (36.66% in group I and 47.91% in group II) are warranted.enThesis