Determining the decreasing trend of maternal immunity against small ruminant morbillivirus in goat kids

BACKGROUND: Small ruminant morbillivirus (SRMV) is the etiological agent of Peste des petits ruminants (PPR) disease. PPR is one of the most important viral diseases of small ruminant husbandry. In the endemic countries, vaccination is the main way to control this disease. Administering the first PPR vaccine in goat kids requires decreased maternal immunity. OBJECTIVE: The aim of this study was to determine the decreasing trend of maternal immunity against SRMV in goat kids born from vaccinated goats. METHODS: Twenty Saanen goat kids were studied in two groups including control (n = 5, receiving colostrum from unvaccinated goats) and treatment (n = 15, receiving colostrum from vaccinated goats). Virus neutralisation (VN) test was used to evaluate serum specific antibodies against SRMV in goat kids from birth to 100 days of age. RESULTS: The first goat kid (n = 1) in the treatment group was seronegative at the age of 28 days. All the goat kids were seronegative at the age of 100 days. The average serum titre of the goat kids at the age of 70–100 days became negative. CONCLUSIONS: Some goat kids became seronegative before reaching the age of receiving the first PPR vaccine. The age of 70–100 days could be a good age range to give the first dose of PPR vaccine to the goat kids, but more studies were needed on the effectiveness of this vaccine at this age range.