Resistance of Calves to Reinfection with Eimeria bovis

Abstract

SYNOPSIS. An immunity to reinfection with E. bovis was demonstrated in 3 experiments involving 60 calves. This immunity develops rapidly, as indicated by resistance to a challenge given 14 days after the immunizing inoculation. In 3 groups of 3 to 6 young calves each, immunity was still present to a moderate degree 2 to 3 months after inoculation; in one group of 5 animals about a year old there was apparently a high degree of immunity about 7 months after the last inoculation. In one experiment an immunizing inoculum of 10,000 oöcysts did not produce as much immunity as 50,000 oöcysts. In 2 experiments there appeared to be little difference in the immunity produced by a single inoculation of 50,000 as compared with 100,000 oöcysts, but inoculation with 100,000 oöcysts, resulted in substantially longer and more severe illness than 50,000 oöcysts. There appeared to be no appreciable difference in clinical symptoms or development of immunity between calves given a single immunizing inoculum and those given the same number of oöcysts in 5 equal inocula on successive days. Treatment with sulfamethazine and sulfamerazine (Merameth) 13 to 15 days after inoculation alleviated the clinical symptoms of coccidiosis without interfering appreciably with the development of immunity. In one experiment with 7 calves, no beneficial effect was noted from 1 or 2 transfusions of 500 ml. of plasma and leucocytes from immune calves into 4 calves 1 and 12 days or 11 days after a challenge inoculation.

Calves gastrointestinal nematodes and Eimeria prevalence and associated risk factors in dairy farms, southern Ethiopia

“…Relatively the lower Eimeria infection during the first three months of age was due to the effect of colostral antibodies from infected cows (Fiege et al, 1992). Again the prevalence of Eimeria species infection declined after 7 months of age probably as a result of immunity development to re-infection by the same species of Eimeria (Senger et al, 1959). Cross protection between species does not occur, and hence, undoubtedly the calves might be infected by other species of Eimeria (Bangoura and Bardsley, 2020).…”

Observations on the duration of the acquired immunity of chickens to Eimeria maxima Tyzzer, 1929

“…For these reasons E. maxima may be more convenient than other species are for the investigation of some aspects of immunity to coccidial infections in fowls. Senger, Hammond, Thorne, Johnson & Wells (1959) have shown that calves immune to E. bovis remained so for a period of 2-3 months, but that calves immunized when they are a year old had a high degree of resistance 7 months later. In E. maxima infection it appears that, although the immunity acquired after a single immunizing infection often develops promptly and is often complete, its duration is relatively short.…”

The Coccidian Parasites (Protozoa, Sporozoa) of Ruminants

“…Large numbers are discharged for 5-7 days, and smaller numbers for 2-3 weeks. In 28 calves studied by Senger et al (1959), oocysts were discharged for 7-15 days with a mean of 11.5 days. Svanbaev (1967a) found that the prepatent period was 17-18 days and the patent period no more than 10 days.…”