Effect of a Natural Trypanosome Infection in Trypanotolerant Cattle Reared in a Tsetse-Infested Area in Southern Gabon and Monitored Under Field Conditions

Abstract

Background: African trypanosomosis is a major constraint to agricultural production in Sub-Saharan Africa. N’Dama has the ability to survive and be productive in tsetse-infested areas without the aid of treatment where other breeds quickly succumb to the disease. Although trypanotolerant, N’Dama can become vulnerable as a result of frequent infections. Results: A comparative study on the effect of trypanosome infection on body weight, chest circumference and Packed Cell Volume (PCV) between naturally infected N’Dama, reared in a tsetse-infested area, versus uninfected N’Dama has been undertaken over 13 weeks. The study was conducted on 29 N’Dama bull calves, 3-year-old, with an average live weight of 242.8±27.25 kg and reared at similar tsetse challenge levels. Fourteen animals infected with trypanosomes belonged to the infected group (n=14), and 15 bull calves randomly selected and having received curative and preventive treatments against trypanosomosis, composed the uninfected group (n=15). Trypanosomes have been detected using PCR. During the study, body weight, chest circumference and PCV of animals of both groups were monitored weekly. The body weight loss was much more pronounced in the infected animals (b = -1.0584) than in uninfected animals (b = -0.2609). The decrease of the average chest circumference was much more marked in the infected group (b = 0.0052) compared with uninfected group (b = 0.0025). However, trypanosome infection had no significant effect on PCV. Conclusion: This study suggests that strict prophylactic programs should be conducted on N’Dama cattle to improve their production, in tsetse-infested areas. DOI: 10.29011/2574-2914. 000027