Revisiting the Value of Reproductive Tract Scores
Reproductive tract scores (RTS) are a tool available to cow-calf producers and their veterinarians that can improve herd reproductive performance and efficiency. Reproductive tract scores can often be performed simultaneously with pre-breeding vaccines, eliminating the need to pen and process cattle an extra time. The objective of reproductive tract scoring is to help producers select for replacement females that reach puberty early, allowing them to conceive early in the breeding season.
Reproductive tract scores are done by manual palpation of the reproductive tract. Scores range from 1 to 5 depending on the structures present on the ovaries and overall tone of the uterus. A reproductive tract score of 1 indicates an infantile reproductive tract with no evidence of reproductive cyclicity present. Scores of 5 indicate well-developed ovaries with presence of a corpus luteum. Heifers with RTS of 4 and 5 should be kept as replacement females. Detecting small differences in the structures present on the ovaries of beef heifers often requires technical skill, so working with your veterinarian to measure RTS is recommended. This also provides your veterinarian an opportunity to be involved in heifer development, assess the overall health status of heifers prior to breeding season.
Reproductive tract scores provide producers with an indirect estimation of age at puberty in beef heifers. The onset of puberty in beef heifers can be detected by observing visual signs of estrus (i.e. heat). In most cow-calf production systems, heifers are expected to have their first calf at 2 years of age. In order for a heifer to calve at two years of age, she must conceive at approximately 15 months of age. It is advantageous for heifers to reach puberty before the breeding season begins so that they have the best chance of conceiving early in the breeding season. In a 50-day artificial insemination (A.I.) program, heifers with a RTS of 4 or 5 had a significantly higher pregnancy rate to first A.I. compared to those with a RTS of 1-3.1 Regardless of whether heifers are artificially inseminated or bull bred, heifers with higher RTS have a better chance of conceiving early compared to those with lower RTS.
Measuring RTS prior to breeding season allows producers to identify those heifers who have reached puberty, or modify the nutritional program to ensure heifers are in adequate body condition to achieve reproductive cyclicity. Nutrition strongly influences onset of puberty, and will be discussed in subsequent blog posts.
For more information on reproductive tract scoring beef heifers, visit the following website:
- Holm DE, Thompson PN, Irons PC. The value of reproductive tract scoring as a predictor of fertility and production outcomes in beef heifers. J Anim Sci 2009;87:1934–1940.