1 / 1

Assessment of voluntary waiting period and frequency of estrus synchronization among herds

Assessment of voluntary waiting period and frequency of estrus synchronization among herds R.H. Miller, 1, * H.D. Norman, 1 M.T. Kuhn, 1 and J.S. Clay 2 1 Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705-2350

razi
Télécharger la présentation

Assessment of voluntary waiting period and frequency of estrus synchronization among herds

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Assessment of voluntary waiting period and frequency of estrus synchronization among herds R.H. Miller,1,* H.D. Norman,1 M.T. Kuhn,1 and J.S. Clay2 1Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705-2350 2Dairy Records Management Systems, Raleigh, NC Abstr. W172 INTRODUCTION • New reproductive management regimes adopted in recent years • Synchronization protocols (ES) • Timed insemination • Voluntary waiting period (VWP) of 60 d assumed by USDA for genetic evaluation of pregnancy rate • Actual herd VWP and frequency of ES relative to traditional estrus detection need to be examined METHODS CONCLUSIONS VWP Determination • Increase in mean DFS from 89 d in 1995 to 94 d in 1998 and then slight decrease • Within herd, reasonably consistent herd means for DFS from year to year (correlation = 0.67) • 10% of cows inseminated before 60 DIM for 70% of herds • 60-d VWP assumed by USDA for calculating pregnancy rate is conservative • Increase in VWP since 1995, but recent moderation ES Herd Identification • Strong trend toward ES/timed AI regimes relative to traditional estrus detection • Steady increase from 0.9% in 1995 to 7.1% in 2001 in relative frequency of ES regimes (probable and ES) • Fewer DFS (16.4 d) and days open (9 d) for ES herds than for herds with traditional estrus detection but more services per cow (0.18) OBJECTIVES • Determine variation in DIM at first service after calving (DFS) among and within herds to assess consistency of VWP • Identify ES herds with timed insemination and compare DFS and number of services between ES herds and those with traditional estrus detection RESULTS DATA • 5.55 million lactation records (DRMS, AgSource) • Inseminations from 1995 through August 2002 • Identified service sires • Holsteins and Jerseys • Pregnancy status unknown • 2529 herds on continual test from 1995 through 2001 • Mean DFS and cows per herd FUTURE RESEARCH • Studies underway to determine if reproductive regime should be considered in genetic evaluations of pregnancy rate

More Related