Journal of Veterinary and Applied Sciences

Abstract
In this study, methanolic leaf extract of Newbouldia laevis was orally administered to rabbit does before breeding and during pregnancy, and the effects on their serum levels of oestrogen and progesterone was evaluated. Twenty New Zealand rabbit does, aged 6 ± 2 months and of a weight range 1.40 – 2.00 kg each, were used for the study. They were randomly assigned to four groups (A, B, C and D) of five each. Rabbits in Groups A, B and C received the methanolic leaf extract of Newbouldia laevis at doses of 1000, 500 and 250 mg/kg, respectively, while those in Group D were the untreated control that were given a distilled water placebo. Rabbits in all the groups were provided with feed and drinking water freely for the 48 days of the study. The varied doses of the extract and the distilled water placebo were administered orally daily for the 48 days of the experiment. The does were mated on day 27 of administration of the extract. Blood samples were collected from the does on days 0, 6, 21, 27, 34, 41 and 48 of the experiment, and serum levels of estradiol (E2) and progesterone (P4) were determined following standard enzyme-linked immunosorbent assay (ELISA) techniques and procedures. Results showed that the serum oestrogen levels were significantly higher (p < 0.05) in the extract treated groups in a dose dependent manner when compared to the untreated control on days 21 and 34, while the mean serum progesterone levels significantly varied (p < 0.05) among the groups on days 6, 21 and 27. It was concluded that administration of the Newbouldia laevis leaf extract as used in the study significantly affected serum oestrogen levels before breeding and during pregnancy, and serum progesterone levels only before breeding. Further studies evaluating the effects of the extract on other reproductive hormones were recommended and proposed.

Keywords: Newbouldia laevis; Methanolic leaf extract; Serum Oestrogen and Progesterone; Rabbit does; Breeding; Pregnancy.

How to cite this article:
Bashir MD, Ibrahim K, Sabo B, Abdullahi MS, Yahaya AA (2025). Oral administration of methanolic leaf extract of Newbouldia laevis to rabbit does before breeding and during
pregnancy: effects on their serum levels of oestrogen and progesterone. Journal of Veterinary and Applied Sciences, 15(1): 937 – 947.

*Correspondence: E-mail: mkaibs2012@gmail.com Phone: +2348037864940

Oral administration of methanolic leaf extract of Newbouldia laevis to rabbit does before breeding and during pregnancy: effects on their serum levels of oestrogen and progesterone
Maryam D. Bashir ¹, Kabir Ibrahim ² *, Bello Sabo ³, Mahmud S. Abdullahi ⁴, Aliyu A. Yahaya ⁵1 Veterinary Teaching Hospital, Bayero University, Kano State, Nigeria.
² Veterinary Unit, Department of Agriculture and Natural Resources, Katsina Local Government Area, Katsina State, Nigeria.
³ Department of Production Technology, Hassan Usman Katsina Polytechnic, Katsina, Katsina State, Nigeria.
⁴ Department of Veterinary Pathobiology, Faculty of Veterinary Medicine, Bayero University Kano, Kano State, Nigeria.⁵ National Animal Production Research Institute, Ahmadu Bello University, Zaria, Kaduna State, Nigeria.