Submitted to: Research Update for Fort Keogh Livestock and Range Research Laboratory
Publication Type: Popular Publication
Publication Acceptance Date: 10/1/2002
Publication Date: 1/15/2003
Citation: GEARY, T.W. PROFITABILITY OF ESTROUS SYNCHRONIZATION WITH NATURAL SERVICE. RESEARCH UPDATE FOR FORT KEOGH LIVESTOCK AND RANGE RESEARCH LABORATORY. p. 34. 2003. Interpretive Summary: Failure to rebreed is the single greatest economic loss to cow-calf producers and is the primary reason for culling cows from the herd. Beef cows often require 50 to 90 days to recover following calving until they resume reproductive (estrous) cycles that allow them to conceive and become pregnant. Cows that do not initiate estrous cycles before the start of the breeding season have fewer opportunities to conceive. These cows continue to calve later and later each year decreasing the age and value of their offspring. The Select Synch estrous synchronization protocol initiates estrous cycles in the majority of cows that have calved at least 40 days previously and can be used to increase the opportunities that cows have within a defined breeding season to conceive. Computer models have demonstrated that use of this program with natural service may yield a 70-fold increase in cow-calf profitability. The goal of this study was to evaluate the impact of the Select Synch protocol under various range conditions on productivity and economic return.
Technical Abstract: Approximately one-half of the cows (n-915) from each of four locations received the Select Synch Protocol or no synchronization at the start of a 50 to 60 day natural service breeding season. Pregnancy rates were 5% higher for cows receiving the Select Synch Protocol than control cows. In addition, Select Synch treated cows calved one day earlier, had 10% more calves born in the first 21 days and had an 11 day shorter calving season. Based on individual weaning weights and increased calf weaning percentages at the three locations where individual weaning weights were obtained and an assumed weaning value of $80/cwt, use of the Select Synch protocol increased net profit by $26.32 per cow exposed.