Some cows do not show heat signs for along time after calving. In this case, no ovulation takes place. The condition can be caused by an infection or inflammation of the uterus and underfeeding of the cow especially with minerals.

Silent heat is the term used when a cow which has shown heat signs before shows heat signs again after 6 weeks or later. The regular heat period at 3 weeks is often referred to as the silent heat. The heat signs might have been weak and therefore not observed. If the cow has been inseminated before, she might have had an early abortion so that she shows heat signs again 6-9 weeks after the last insemination.

This is one of the most common congenital abnormalities affecting female cattle. It occurs when both male and female conceptus are present in the same uterus. In cattle there is tendency for the placenta of twin fetuses to merge thereby causing the circulatory system of the twins to become interconnected. This often affects the development of the female sex organs of the female twin probably due to the androgens of the male blood circulation.

Culling of freemartin heifers

This condition has been estimated to account for about 5% of infertility in heifers. The condition is an abnormality when the reproductive tract of white heifers gets blocked during development. Unlike freemartins, the cow's ovaries are well developed and functional and therefore estrus and ovulation takes place normally. However, fertilization may not take place depending on the site of the reproductive tract that is obstructed.

This is the inflammation of the endometrium, internal lining and mucus membrane of the uterus. It occurs as a result of an infection by microorganisms. Infection normally occurs during mating or around parturition by such organisms as Campylobacter fetus or Trichomonas fetus and other opportunistic bacteria like the Corynobacterium pyogenes, E. coli and Fusobacterium necrophorum. Endometritis often occurs as a sequel to dystocia and or retained placenta.

Routine and strict hygiene at calving:
Cows should be kept clean at calving and that calving boxes are cleaned and disinfected.

This condiytion is due to an accumulation of pus in the uterus and can as well occur as a sequel to chronic endometritis or may result from the death of an embryo or fetus with subsequent infection by Corynobacterium pyogenes. The situation may persist undetected for some time and may be confused for pregnancy.

Treatment used by estrogens and oxytocin