Revista de salud animal y ciencias del comportamiento

Cause for the Occurrence of Freemartin and its Influence on Livestock Reproductive Performance: A review

Abstract

Alemitu Adisu*, Wondosen Zewdu and Tesfaye Moreda

Livestock reproductive performance is a prerequisite for any successful livestock production program and it is depends up on the factors viz. parturition interval, ovarian activity, days open, fertility and age at first parturition, litter size and annual reproductive rate. However, the above mentioned factors are influenced directly or indirectly by the occurrence of freemartin animal within the flock or farm. The objective of this review was to organize the condensed information about the causes for the occurrence of freemartin, development and way of examining a freemartin animal and its influence on livestock reproductive performance. A freemartin is genetically female, but has many characteristics of a male. The ovaries of the freemartin do not develop correctly, and they remain very small, also the ovaries do not produce the hormones necessary to induce the behavioral signs of heat. The external vulvar region can range from a very normal looking female to a female that appears to be male. Usually, the vulva is normal except that in some animals an enlarged clitoris and large tufts of vulvar hair exist. It can be diagnosed in a number of ways ranging from simple examination of the placental membranes to chromosomal analysis. Understanding about the freemartin syndrome is important to take measure by the livestock keepers, farm managers or veterinarian to cull the heifer at her early age or keep it as a teaser bull and/or as draft animal.