Observations on placentome diameters in gestating West African dwarf does experimentally infected with <i>Trypanosoma brucei</i>

Abstract

This study investigated the effect of experimental Trypanosoma brucei infection on the placentome diameter (PD) of twenty four gestating West African dwarf does. The does were randomized into 4 equal groups with ‘G1’ as control while ‘G2’, ‘G3’ and ‘G4’ were intravenously inoculated with 5 x 10⁸ trypanosomes on days 25, 51 and 101 post breeding (PB), respectively. Real-time trans-abdominal scan was carried out with 3.5-5MHz convex transducer. The differences between the mean PD readings on days 60, 75 and 132 for ‘G1’ (1.18 ± 0.32, 1.63 ± 0.83 and 2.43 ± 0.69) cm, ‘G3’ (1.20 ± 0.82, 0.49 ± 3.13) cm and ‘G4’ (1.19 ± 0.26, 1.65 ± 0.05 and 2.39 ± 1.16) cm, respectively were statistically significant (P ≤ 0.05). At day 60, the mean value for does in ‘G1’ (1.18 ± 0.32) cm was significantly (P ≤ 0.05) higher than for ‘G2’ (0.88 ± 1.53) cm. At day 75, the mean value for does in ‘G1’ (1.63 ± 0.83) cm was significantly (P ≤ 0.05) higher than for ‘G3’ (0.49 ± 3.13) cm. At day 132, the difference between the mean values of PD for does in ‘G1’ (2.43 ± 0.69) cm and ‘G4’ (2.39 ± 1.16) cm was not significant (P ≥ 0.05). The placenta tissue loss following infection for ‘G2’ and ‘G3’ were 25.4% and 69.9% at 36 DPI and 25 DPI, respectively. No values were obtained at days 75 and 132 for does in ‘G2’ and at day 132 for does in ‘G3’ either due to abortion or death. These findings indicate that experimental T. brucei infection led to reduced placentome diameter during critical periods of increased foetal development.

Keywords: Gestation, Placentome diameter, Trypanosoma brucei, Ultrasonography, West African dwarf does