Analysis of trait-based variation in bovine exposure to viral respiratory tract infections at the wildlife-livestock interface in the Mnisi communal farming area of South Africa

Abstract

Animal diseases have always been one of the main constraints on animal production, especially in Africa where there are a variety of tropical and subtropical diseases. Knowledge of these diseases and the development of approaches to combat them is highly relevant to the socio-economic development of Africa and its fight against poverty. Serological tests were performed to determine seroprevalence and important risk factors for occurrence of respiratory pathogens in cattle on 423 biobanked sera collected from cattle at 11 dip tanks in the Mnisi communal farming area which is on the edge of the Kruger National Park. These pathogens are known to cause significant production losses in livestock by predisposing animals to secondary infections including pneumonia. A pentavalent, indirect ELISA test was performed to estimate seroprevalence of bovine herpesvirus-1, bovine respiratory syncytial virus, bovine viral diarrhea virus, parainfluenza virus-3 and bovine adenovirus-3 infections in cattle at the wildlife-livestock interface in the Mnisi communal farming area. Previous exposure to the five pathogens was determined. Additionally, the data was analyzed using the statistical software R to determine important risk factors that predicted exposure to the pathogens in cattle, namely population factors (distance from interface and month of collection) and individual characteristics (age, sex, body condition and breed). Age and body condition of the animals were found to have an effect on seropositivity while breed, sex, spatial distribution of the animals and month of sample collection did not have an effect. Recommendations to reduce pathogen exposure and improve production are made to the livestock owners in the Mnisi community.