Leptospira interrogans serovar hardjo vaccination of pregnant beef cows and subsequent growth rate of progeny.
Five experiments with Leptospira interrogans serovar hardjo vaccine were carried out over a 6-year period in pregnant Brahman-cross and Sahiwal-cross cows in the dry tropics on northern Queensland. The numbers ranged from 127 breeders aged 2 to 5 years in 1972 to 344 breeders aged 2 to 9 years in 1977. Half of the cows were vaccinated twice in mid-pregnancy except for 1977, when they were vaccinated once. In 1975-1977 inclusive, half of the heifers were given an additional dose of vaccine at commencement of mating. Vaccination caused a significant (P less than 0.01) reduction of prenatal loss but not of perinatal or postnatal losses. Growth rates of calves from vaccinated and unvaccinated dams were similar.
D000818:Animals; D002417:Cattle / Q000254:growth & development* / Q000276:immunology / Q000502:physiology; D005260:Female; D007919:Leptospira / Q000276:immunology*; D008297:Male; D011247:Pregnancy; D011270:Pregnancy, Animal; D014611:Vaccination / Q000662:veterinary*