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Comparison of Sex-sorted Semen with Conventional Semen in the Reproductive Performance of Dairy Heifers

Posted: August 27, 2007

Based on a large data set of first services (16,587), J.M. DeJarnette and coworkers at Select Sires, Inc. compared the reproductive performance of Holstein heifers inseminated with sex-sorted semen (SS) vs. conventional non-sorted semen (CS).

Although this was not a controlled study it does provide a descriptive summary based upon a large number of services. Results were obtained from electronic herd records and personal communication with herd managers. When conception rates for CS were not available the conception rate was assumed to be 60 percent for CS.

The average conception rate at first service for SS was 85 ± 2.9 percent of that achieved for CS. However, 74 percent of the herds achieved conception rates greater than 70 percent of that obtained with CS. For the 25 herds that used = 100 doses of SS, conception to SS averaged 48 ± 1.9 percent (range 33 to 72 percent) compared to conception of 54 ± 1.8 percent (range 38 to 70 percent) for CS. For the heifers that failed to conceive to artificial insemination, the percentage inseminated within the normal 18 – 24 day interval at the next service was significantly greater for SS (70 percent) than CS (64 percent). The authors suggested this may be due to better heat detection rates for SS bred heifers or possibly increased rates of fertilization failure to SS.

Abortion rate did not differ for heifers that conceived to SS or CS. Although this is descriptive summary from a large data set and there may be bias associated with semen use, it does illustrate that greater than 70 percent of the herds achieved first service conception rates for heifers that were = 70 percent obtained when using CS. For single births, the percentage of female calves born was 90 percent (3,361 calves) and 48 percent (10,999 calves) for SS and CS, respectively. (Abstracted from J.M. DeJarnette et al., 2007 annual meeting of ADSA and ASAS)

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Michael O'Connor
Dairy and Animal Science Extension