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ARS Home » Plains Area » Clay Center, Nebraska » U.S. Meat Animal Research Center » Livestock Bio-Systems » Research » Publications at this Location » Publication #372528
Research Project: Improving Livestock Production by Developing Reproductive and Precision Management Technologies

Location: Livestock Bio-Systems

Title: Environmental parameters may increase likelihood of beef heifers classified with earlier or later pubertal attainment

Author
item KEANE, JESSICA - University Of Nebraska
item NAFZIGER, SARAH - University Of Nebraska
item BERGMAN, JEFF - University Of Nebraska
item KURZ, SCOTT - University Of Nebraska
item SNIDER, ALEXANDRIA - University Of Nebraska
item BOCHANTIN, KERRI - University Of Nebraska
item WOOD, JENNIFER - University Of Nebraska
item Cushman, Robert - Bob
item SUMMERS, ADAM - New Mexico State University
item CUPP, ANDREA - University Of Nebraska

Submitted to: Society for the Study of Reproduction Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/24/2020
Publication Date: 6/24/2020
Citation: Keane, J.A., Nafziger, S.R., Bergman, J.W., Kurz, S.G., Snider, A.P., Bochantin, K.A., Wood, J.R., Cushman, R.A., Summers, A.F., Cupp, A.S. 2020. Environmental parameters may increase likelihood of beef heifers classified with earlier or later pubertal attainment [abstract]. Society for the Study of Reproduction Annual Meeting. Virtual Abstract Program p. 67-68. Available: https://www.ssr.org/news-events/past-meetings/ssrvirtual2020

Interpretive Summary:

Technical Abstract: We have identified 4 pubertal classifications from 754 heifers born during 2012-2018: 1) Early-greater than 1 ng/ml of progesterone(P4) and continued cyclicity (317±4 days of age (DOA), n=143); 2) Typical (378±2 DOA, n=279) with continued cyclicity; 3) Start- Stop- P4=1ng/ml at 265±4 but discontinued cyclicity (n=91); and 4) Non-Cycling - no occurrence of P4=1ng/ml during sampling period (n=98). Heifers that achieved puberty with continued cyclicity had greater reproductive performance (Early and Typical) their first calving season. However, the distribution of heifers classified into each puberty there was reduced monthly high temperatures (p<0.04), lower rain-per-day-ratios (p<0.02), and greater monthly snowfall (p=0.001). Conversely, there were greater numbers of heifers classified as Typical or Non-Cycling heifers in years that had a greater rain-per-day-ratio (p<0.001) and reduced monthly snowfall (p=0.002). Taken together our data indicate that classification of heifers reaching 1 ng/ml of progesterone at reduced DOA (Early and Start-Stop) were from dams exposed to reduced high temperatures; whereas, heifers that reached puberty at greater DOA (Typical and Non-Cycling) had dams exposed to hot temperatures (high). After weaning, heifers classified as Early and Start- Stop were more often exposed to environments with reduced rain-per-day-ratios and greater snowfall which may have led to environmental stress inducing puberty. In contrast, females that took longer to become pubertal, Typical and Non-Cycling heifers, were more often classified in years with a greater rain-per-day-ratio and less snowfall. Start-Stop and Non-Cycling classified heifers have reduced reproductive performance in their first year of calving, thus, future research will determine how environmental impacts may interact with genetics and age of dam to affect puberty and subsequent reproductive performance.