Publicación:

Perdida embrionaria en bovinos.

Resumen

Embryonic loss is an important cause of pregnancy in cattle, accounting for 25 to 40% of pregnancy failure that can be divided into early and late, and early embryonic loss of 40% can be achieved. In cattle, early embryonic loss occurs most of the day 7 to 16 of gestation, during the blastocyst outbreak and the application without affecting the duration of the cycles (JAINUDEN; HAFEZ, 2004). This loss of gestation occurs during the first 42 days some authors report up to 45 days corresponding to the embryonic period, which makes diagnosis difficult and correcting in bovine reproduction. This pathology is present in both beef and dairy cattle (Thatcher et al., 1994; Vanroose et al., 2000; Sreenan et al., 2001), and according to Wathes (1992), most embryonic deaths occur In the first days after fertilization and during the implantation process. Embryonic losses can be classified into early embryonic mortality, occurring within the first 25 days of gestation, and late embryonic mortality occurs between 25 and 45 gestation (Humblot, 2001). The terms fetal death or miscarriage refer to the losses that occur between days 45 and 260 (FORAR, 1996). In current production systems, it is extremely important to recognize the multiplicity of factors that may influence reproductive performance, especially the causes of embryonic mortality. The various factors can be divided, according to Grunert (2005), into genetic factors, management, stress, animal health, among others. According to Kastelic (2003) these factors are classified as endogenous (possibly referring to the embryo, the cow or the bull) and environmental factors.