Photo: Life Cycle Of Coccidia In Cattle
10/08/2008 09:31AM
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Life Cycle Of Coccidia
Bovine coccidia have stages both within the host animal as well as outside. The developmental stages in the animal give rise to a microscopic egg (called an oocyst), which is passed out in the manure (Figure 1).
Under proper conditions of temperature, moisture and oxygen, the oocyst develops within three to seven days and is now capable of infecting cattle. At this stage, the oocyst contains eight bodies (called sporozoites), each of which is capable of entering a cell in the animal’s intestine after the oocyst is eaten.
When a sporozoite enters a cell, it changes into a meront and divides many times, producing up to 100,000 offspring called merozoites. The numbers produced depend on the species of coccidia involved. Each offspring, in turn, may enter another intestinal cell. This cycle is repeated several times. Because of this multiplication of parasite stages, large numbers of intestinal cells are destroyed.
Eventually, the cycle stops and sex cells (male and female) are produced. The male fertilizes the female to produce an oocyst, which ruptures from the intestinal cell and is passed in the manure. Thousands of oocysts, each containing eight sporozoites when mature, can be passed in the manure of an infected animal.