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ARS Home » Plains Area » Clay Center, Nebraska » U.S. Meat Animal Research Center » Nutrition, Growth and Physiology » Research » Publications at this Location » Publication #339203
Title: Endocrine profiles during attainment of puberty may predict reproductive longevity in heifers

Author
item NAFZIGER, SARAH - UNIVERSITY OF NEBRASKA
item ABEDAL-MAJED, MOHAMED - UNIVERSITY OF NEBRASKA
item TENLEY, SARAH - UNIVERSITY OF NEBRASKA
item SUMMERS, ADAM - NEW MEXICO STATE UNIVERSITY
item HART, MARIAH - UNIVERSITY OF NEBRASKA
item HARSH, GAVIN - UNIVERSITY OF NEBRASKA
item BERGMAN, JEFF - UNIVERSITY OF NEBRASKA
item KURZ, SCOTT - UNIVERSITY OF NEBRASKA
item WOOD, JENNIFER - UNIVERSITY OF NEBRASKA
item Cushman, Robert - Bob
item CUPP, ANDREA - UNIVERSITY OF NEBRASKA

Submitted to: Society for the Study of Reproduction Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/11/2017
Publication Date: 7/10/2017
Citation: Nafziger, S., Abedal-Majed, M.A., Tenley, S., Summers, A., Hart, M., Harsh, G., Bergman, J., Kurz, S., Wood, J., Cushman, R.A., Cupp, A.S. 2017. Endocrine profiles during attainment of puberty may predict reproductive longevity in heifers [abstract]. Society for the Study of Reproduction Annual Meeting. Abstract #P281 (Scientific Program p. 332). Available: http://www.ssr.org/sites/ssr.org/files/uploads/attachments/node/482/ssr2017abstracts.pdf

Interpretive Summary:

Technical Abstract: We hypothesized that attainment of puberty through initiation and continuation of cyclic activity may be a predictor of reproductive longevity in heifers. Blood plasma was collected from 379 spring born heifers over four years from weaning to prior to breeding (October-June) in 2012-2015. Four puberty classifications were detected via SAS using time and concentrations of progesterone (P4) > 1ng/ml with continued cyclicity over the sampling period: 1) Early Puberty- 253.4±10.8 days of age with continued cyclicity; 2) Typical Puberty- 374.6±3.6 days of age with continued cyclicity; 3) Start-Stop Puberty- 261±3.9 days of age with discontinued cyclicity; and 4) Non-Cycling- no P4 > 1ng/ml during the sampling period. Early Puberty heifers had the greatest P4 concentrations (3.11±0.14ng/ml; P < 0.05) during the pre-pubertal period (October-April) followed by Start-Stop (1.25±0.07ng/ml), Typical (0.90±0.08ng/ml), and Non-Cycling (0.38±0.14ng/ml). There was no influence of any group on AI pregnancy rate (P > 0.05). In 2014 (N=10) and 2015 (N=12), 7 Early, 3 Typical, 9 Start-Stop, and 3 Non-Cycling were more intensively evaluated from April-June (peripubertal period) with daily blood collection, ultrasound, and ovariectomy. Daily concentrations of P4 during this intensive peripubertal period were greater in Early Puberty heifers than Start-Stop and Non-Cycling (3.3174±0.50ng/ml vs. 1.9379±0.40ng/ml or 0.0±1.22ng/ml; P < 0.05), but not Typical (2.03±0.61ng/ml). Non-esterified fatty acid (NEFA) concentrations in follicular fluid from the peripubertal period were greater in Early Puberty heifers (0.35±0.02mEq/L; P < 0.05) than in Start-Stop (0.29±0.02mEq/L), but not different from Typical heifers (0.35±0.04mEq/L). Serial blood collections during the peripubertal period were conducted (15 min intervals for 8 h) on 2 heifers from each group in the 2015-born heifers to determine LH and FSH mean concentrations, LH pulse amplitude, and frequency. Early Puberty heifers tended to have greater LH pulse amplitude than other groups (1677.75±332.623ng/ml vs. 6.67±332.6ng/ml; P < 0.08); however, there were no differences in LH mean concentration or pulse amplitude. Non-Cycling heifers had greater mean concentration of FSH than other groups (541.12 vs. 315.93ng/ml; P < 0.05). Prior to ovariectomy, heifers were stimulated with FSH (140mg/cow at 12-h intervals over 4 days) to determine response at ovariectomy. Early Puberty heifers had greater total ovarian area at ovariectomy compared to all groups (779.29±41.1583 mm2; P < 0.01), while Start-Stop (547.90±41.1583 mm2) and Non-Cycling (534.34±41.1583 mm2) had greater ovarian area than Typical heifers (387.41±41.1583 mm2; P < 0.05). Ovarian cortical cultures were conducted on cows that were previously classified at puberty in 2012-2014. Interestingly, ovarian cortex from Start-Stop and Non-Cycling cows secreted higher androstenedione (18.3-fold higher; P < 0.05) in culture media during the first two days of culture compared to Typical cows. Taken together, the reduced P4 concentrations during the peripubertal period (Start-Stop and Non-Cycling), reduced NEFA (Start-Stop), increased FSH (Non-Cycling) and excess androstenedione secreted in ovarian cortex from cows previously identified as Start-Stop and Non-Cycling may predispose these females to reduced reproductive longevity in comparison to Early and Typical classification heifers.