The final factor, and the one which has the greatest likelihood of being controlled, according to Anderson, is a condition known as "anestrus,"   a period of time in which a cow does not have any viability for reproduction that is often associated with the period of time following the birth of a calf.    From Wordnik.com.  [Siskiyou Daily News Homepage RSS] Reference

Mares on the average cycle from about February through about October, with a dormant period anestrus in the winter.    From Wordnik.com.  [BOOK VIEW CAFE BLOG » A Day in the Life of a Breeding Farm] Reference

(Although it is possible to freeze the buffalo semen now, further improvements are needed to achieve higher conception rates.) · Incidence of sub-estrus and anestrus.    From Wordnik.com.  [11 Recommendations and Research Needs] Reference

"Seasonal anestrus" - no GnRH = no FSH/LH - ovaries largely dormant - uterus atrophies.    From Wordnik.com.  [Recently Uploaded Slideshows] Reference

Although the mechanism is not understood, he said, nursing and the physical presence of the calf appear to initiate the period of anestrus.    From Wordnik.com.  [Siskiyou Daily News Homepage RSS] Reference

He said that a number of factors have shown to control the length post-partum anestrus, including the presence of the newborn calf; the age of the mother cow; and the body condition score, which is a numerical representation of the cow's physical condition.    From Wordnik.com.  [Siskiyou Daily News Homepage RSS] Reference

Luteal Cysts: - follicle that only partially ovulates, because of inadequate LH - a problem mainly of cattle, not horses Clinical Signs: - anestrus (occurring post-partum usually) - Can palpate a unilateral, 35-50 mm diameter, round, smooth, thick walled structure on the ovary 63.    From Wordnik.com.  [Recently Uploaded Slideshows] Reference