Study detailing the dynamic use of sexed semen and bovine semen in dairy cow breeding

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Over the past decade, the use of advanced breeding technologies has exploded in dairy breeding due to the increased efficiency and precision of the resulting offspring. Cow breeders can use sexed semen to predict the sex of offspring that will be produced with approximately 90% reliability.1 Commercial producers sort sperm using flow cytometry or a selective destruction process to create samples containing sperm enriched with X or Y chromosomes. Alternatively, beef semen is used to create crossbred offspring of dairy and beef without replacement that holds an increased market value compared to less profitable dairy bulls.

Many factors influence the decision to use sexed semen or beef semen. Sexed semen carries a higher cost, so its use in herds with poor reproductive performance may not result in positive calf income over semen costs (ICOSC) as much as a herd with better reproductive performance. In addition, sexed semen is traditionally reserved for nulliparous cows due to the lower expected efficiency in multiparous cows. Although it is known that the use of these techniques has increased, prior to this study no detailed data was available to understand exactly how the use of sexed semen and bovine semen is changing the livestock landscape. .

In a study published in the Journal of Dairy Science,2 Researchers evaluated the use of sexed semen and bovine semen in a large proportion of dairy cattle herds in the United States. The primary objective was to determine sperm type, prevalence and attribution in Holstein and Jersey females by year, parity, service number (number of insemination attempts) and herd size. A secondary objective was to determine the prevalence of beef cows bred with Holsteins or Jerseys to produce crossbred calves.

Using data from the Dairy Records Management System (DRMS), this study included records of approximately 42% and 27% of total dairy cows and heifers, respectively, and approximately 40% of total dairy herds licensed to UNITED STATES.2

From 2019 to 2021, inseminations of Holstein females with beef sperm increased overall and tended to increase for Jersey females as the number of services increased. Although the total number of inseminations with sexed semen increased in Holstein and Jersey females from 2019 to 2021, the use of sexed semen decreased as the number of services increased.

Dairy producers likely use more sexed semen at first service due to the greater fertility associated with first service. Conversely, bovine sperm inseminations increased with increasing parity and number of service for Holstein and Jersey females, respectively.2 Dairy producers preferentially use the sexed semen of younger females from the first mating because on average, their genetic merit and fertility are greater than those of older females. Thus, farmers distribute sexed semen and bovine semen differently depending on the registration number and parity of the cow. Additionally, the data showed that the increase in sexed and bovine semen inseminations is due to larger dairy herds assigning semen type based on parity and service number rather than larger dairy herds. small.

This study clearly evaluates and displays the dynamic differences in the current dairy cow breeding landscape and may be useful for those looking to strategize their own breeding plans.

The references

  1. Holden SA, Butler ST. Summary: Applications and advantages of sexed semen in dairy and cattle herds. Animal. June 2018;12(s1):s97-s103. doi: 10.1017/S1751731118000721
  2. Lauber MR, Peñagaricano F, Fourdraine RH, Clay JS, Fricke PM. Characterization of prevalence and sperm type assignment in Holstein and Jersey females in the United States. J Dairy Sci. 2023;106(5):3748-3760. doi:10.3168/jds.2022-22494

Bechtold is a 2024 PharmD candidate at the University of Connecticut


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