HAEMATOLOGICAL VALUES, SEMEN CHARACTERISTICS AND GONADAL/EPIDIDYMAL SPERM RESERVES OF RABBIT BUCKS EXPERIMENTALLY INFECTED WITH TRYPANOSOMA BRUCEI BRUCEI OPALUWA

HAEMATOLOGICAL VALUES, SEMEN CHARACTERISTICS AND GONADAL/EPIDIDYMAL SPERM RESERVES OF RABBIT BUCKS EXPERIMENTALLY INFECTED WITH TRYPANOSOMA BRUCEI BRUCEI OPALUWA

Abstract

This study was designed to determine the haematological values, semen characteristics, gonadal and epididymal sperm reserves of rabbit bucks experimentally infected with T. brucei brucei. Twenty healthy adult male rabbit bucks were randomly divided into two groups of ten each as control group A and infected group B. The rabbits were kept under intensive management and their pre-infection baseline data on haematological parameters and semen characteristics were taken twice weekly between Mondays and Wednesdays and weekly respectively, for two weeks prior to experimental infection. Stabilates were acquired from the Department of Parasitology and Entomology of the Faculty of Veterinary Medicine, Ahmadu Bello University, Zaria who also sourced it from NITR, Kaduna State. Group B rabbits were infected with 1 ml of the parasites containing 1 X 106 trypanosomes, while group A bucks were left uninfected. Group B infected bucks were monitored for six weeks while the ten others served as control post infection. Blood was collected from each rabbit by venipuncture of the ear vein into heparinised capillary tubes thrice a week (Mondays, Wednesdays and Fridays) between the hours of 9.00 – 11.00 hrs from both groups and analyzed for packed cell volume, haemoglobin and plasma protein. The infected rabbit bucks had mean parasitaemia values of 1.99±0.25. There was progressive decrease in PCV giving total mean values of 40.07±0.49 % and 36.42±1.15 % for group A and B respectively, Haemoglobin concentration had mean values of 14.31±1.01 g/dl and 12.21±0.39 g/dl for group A and B, while plasma concentration had mean values for group A and B as 6.48±0.08 gms/100ml and 6.41±0.17 gms/100ml. Semen was collected once a week (Wednesdays) between the hours of 9.00 – 11.00 hrs from both groups. The semen samples were evaluated for colour, pH, motility, volume, morphology, concentration and spermatozoa live dead ratio. The control bucks had a semen volume total mean value of 0.52±0.05 8 mls, compared to the infected bucks with a total mean value of 0.43±0.08 mls. There was a consistent decrease in the semen motility from week six post infection giving mean values of 64.67±4.83 % for control group and 45.20±5.79 % for infected group. Spermatozoa concentration progressively decreased from five weeks post infection to ten weeks post infection. Control group had the highest mean spermatozoa concentration of 165.80±23.13 X106/ml at week five and lowest mean of 50.80±17.81 X106/ml at week one. Spermatozoa morphology had a mean value of 38.73±1.21 % for normal cells and 17.84±1.32 % for the infected group, detached heads had a mean value of 9.46±1.57 % and 3.85±0.40 % for control and infected groups respectively. Folded tails had mean values of 8.43±1.05 % for control group and 3.92±0.54 % for infected group. The mean values for bent tails for the control group was 11.35±0.90 % and 6.36±1.18 % for infected group. Percentage live sperm cell ratio control group had live mean values of 59.33±2.21 % compared to infected group that had live mean values of 48.11±5.86 %. At the end of the experiment, two bucks from each of the groups were sacrificed, their testes were harvested for the determination of gonadal and epididymal spermatozoa reserves. The mean gonadal spermatozoa reserves of group A and group B rabbit bucks were 247.6 ± 65.13 X106/g testis and 173.1 ± 26.88 X106/g testis, respectively. The mean epididymal spermatozoa reserves of group A and group B rabbit bucks were 96.50 ± 31.61 X106/g and 30.92 ± 12.94 X106/g, respectively. It is therefore concluded from this study that trypanosomosis has adverse effects on haematological values, semen characteristics and gonadal and epididymal sperm reserves of rabbit bucks. This study has shown that T. brucei brucei is pathogenic to rabbit bucks causing serious reproductive disorders which may have a negative effect on rabbit production and the socio-economic wellbeing of the farmers and people in the tsetse endemic areas in the country where rabbit farming is important.

HAEMATOLOGICAL VALUES, SEMEN CHARACTERISTICS AND GONADAL/EPIDIDYMAL SPERM RESERVES OF RABBIT BUCKS EXPERIMENTALLY INFECTED WITH TRYPANOSOMA BRUCEI BRUCEI OPALUWA

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