Abstract: | Twenty-four Thoroughbred mares with breeding histories of having been barren for at least the previous 12 months were evaluated in a double-blind feeding trial to determine the effects of chelated mineral supplementation upon subsequent breeding performance. At the start of the trial (Day 0), mares were split into three dietary treatment groups of eight mares each and fed: (a) control diet with macro- and microminerals fed at NRC recommended levels for maintenance of the mature horse, (b) chelated minerals supplementation and (c) inorganic minerals supplementation at levels equal to Group B. Sixty days after initiation of the trial, there were no differences (P>0.05) between age, endometrial biopsy classification, calculated body weight and body condition score for mares between dietary treatment groups. A breeding performance trial was initiated at this time (Day 60). The number of first cycle and cumulative (i.e. over 3 estrous cycles) conceptions, number of first cycle and cumulative pregnancies and the number of total embryonic losses were not different (P>0.05) between the control and either the chelated mineral or the inorganic mineral groups. There were no harmful effects observed from feeding the chelated minerals 60 days prior to, and during, this breeding trial. |