Growth Performance, Semen Quality Characteristics and Hormonal Profile of Male Rabbit Bucks Fed Rubia Cordifolia Root Extracts

Abstract

32 – 7 weeks weaned male rabbits (Newzealand × Chinchilla) weighing 611.3 ± 10 g were randomly distributed into 4 groups of 8 rabbits per treatment with one animal per replicate in a completely randomized design. Rabbits in treatment 1 (control) designated as T1 was fed basal diet with 0 mL Rubia cordifolia root extracts (RCE) while T2, T3 and T4 were fed basal diet with 20 mL, 40 mL and 60 mL per litre of water/day. Basal diet was formulated to meet the nutrient requirements of growing rabbits according to the recommendation of National Research Council (NRC, 1977). The experiment lasted for 12 weeks during which strict biosecurity measures were observed. Feed and water were also given ad libitum. Gas chromatography mass spectrometry of Rubia cordifolia root extracts reveals the presence of 21 bioactive compounds which accounts for 92.46 %. 9-Octadecenoic acid had the highest concentration (29.16 %) while 4-Methoxy-2-nitroformanilide had the lowest concentration (0.02 %). Average body weight gain (ADWG) and feed conversion ratio of rabbits in T4 were better (P˂0.05) compared to the other treatments. Average daily feed intake (ADFI) in T1 was similar to T2 and T3 but slightly higher than T4 (P˃0.05). Highest mortality was recorded in T1 (2.51 %) followed by T2 (0.05 %) none was recorded in T3 and T4 (P˂0.05). Testosterone, luteinizing hormone and thyroid stimulating hormone values were significantly (P˂0.05) influenced by the treatments while follicle stimulating hormone were not significantly (P˃0.05) different among the treatments. Semen results showed a significant (P˂0.05) decrease in sperm concentration, live sperm and motility with a significant (P˂0.05) increase in abnormal sperm compared to the other treatments. It can be concluded that Rubia cordifolia root extracts has bioactive compounds with therapeutic properties and could be tolerated by rabbit bucks up to 60 mL per litre without causing any negative effect on the general health and performance of animals.