Abstract

A total of seventy-two (72) sexually mature rabbits comprising 36 bucks and 36 nulliparous does were subjected to a study to evaluate their physiological responses to oral administration of methanolic extract of a medicinal plant- Andrographis paniculata commonly known as king of bitters. The rabbits were grouped into 2 experimental units based on their sexes and were randomly assigned into four treatment groups designated as T₁, T₂ T₃ and T₄ in a completely randomized design (CRD) with each treatment consisting of nine rabbits.  The rabbits were fed concentrate diet of 16% crude protein and 2630 kcal/kg ME, alongside grass-legume forages. Methanolic extract of Andrographis paniculata was administered orally to the experimental rabbit using a sterile syringe at the rates of 0.0mg/kg, 125mg/kg, 250mg/kg and 500mg/kg for T₁ (control), T₂, T₃ and T₄ respectively. Results obtained for semen parameters at 28 and 56 days of administration of extract showed significantly lower (P<0.05) values for total viable sperm, total sperm per ejaculate and normal sperm proportion in the treated groups. Similarly, seminal plasma fructose and glucose declined significantly (P<0.05) with increase in administration rate.  Final weight, weight gained and dress percentage was higher (P<0.05) in the treated group compared to the control. Serum protein was observed to increase following consumption of the extract. Luteinizing Hormone and testosterone levels were higher (P<0.05) in the treated bucks. Also, an increase in consumption rate of the extract led to lower (P<0.05) total cholesterol, LDL, VLDL and serum glucose levels. Reproductive performance in the rabbit does showed lower (P<0.05) values for conception rate, litter size and weight at birth in the treated group. Premature kits were recorded at full term gestation in T₃ and T₄ rabbit does. This is suspected to be associated with a decline in the serum progesterone levels recorded in the rabbit does following administration rates of 250mg/kg and 500mg/kg. Results obtained for blood parameters in the does followed a similar pattern as those of the bucks. Histopathological studies revealed degenerative changes in the seminiferous tubule architecture of the bucks and a moderate to severe disruption of ovarian follicles in the females. Findings of this study suggest that the A. paniculata extract administered to the rabbits had positive influence on meat quality; however, reproductive performance in both male and females were negatively affected. It is concluded from this study that Andrographis paniculata adversely affects reproduction in both male and female rabbits.