In cooperative breeders, sexually mature subordinates can either queue for chances to inherit the breeding position in their natal group, or disperse to reproduce independently. The choice of one or the other option may be flexible, as when individuals respond to attractive dispersal options, or they may reflect fixed life-history trajectories. Here, we show in a permanently marked, natural pop...

A high incidence (about 70%) of alteration in endometrial epidermal growth factor (EGF) profile, i.e., loss of 2 peaks on days 2-4 and 13-14, has been linked to a reduced fertility in multiparous repeat breeder Holstein cows. However, the EGF profile in Holstein heifers and other breeds (types) of cattle has not been investigated. In study 1, EGF concentrations were determined using endometrial...

adjusted milk yield for 305 days and two milking times along with actual first lactation records of 187138 holstein cows were used to find out the effect of record adjustment on variance components estimation and on genetic evaluation. records had been gathered by the animal breeding center of iran during years 1991 to 2006. the pedigree file included 288032 animals. a single animal model with ...