HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Interpretive Summary Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by de Vries, A. Articles by Conlin, B. J. Search for Related Content PubMed PubMed Citation Articles by de Vries, A. Articles by Conlin, B. J.

Economic Value of Timely Determination of Unexpected Decreases in Detection of Estrus Using Control Charts¹

Department of Animal Science, University of Minnesota, Saint Paul 55108

Corresponding author: A. de Vries; e-mail: devries{at}animal.ufl.edu.

Total economic effects of decreased estrus detection efficiency (EDE) are a function of the economic loss per day and the length of the decrease. A stochastic dynamic dairy herd simulation model was used to determine whether estimates from permanently different EDE rates in herds of 100 and 1000 cows could approximate net returns due to temporary decreases in EDE. The default EDE was 65% and was either permanently or temporarily decreased to 55, 45, or 35%. Temporary decreases in EDE were assumed to continue until identified using cumulative sum or Shewhart control charts. Marginal changes in net return were greater at lower permanent rates of EDE, with losses ranging from $0.73 to 1.24 per extra day open. Temporary decreases in EDE typically yielded smaller effects on net return than permanent decreases, but estimates were not consistently significantly different. However, temporary (30 to 960 d) decreases in EDE affected projected herd economic performance for several years after EDE was reset to 65%. Total losses in net return due to temporary decreases in EDE ranged from $4.44 (accepting more false alarms) to $12.53 (fewer false alarms) per cow for the 100-cow herd. For the 1000-cow herd, total losses in net return ranged from $0.95 to 10.43 per cow. Total losses were not dependent on magnitude of decreased EDE because lower EDE could be detected earlier, thereby compensating for higher daily losses; for example, 35% EDE resulted in lower total losses than 55% EDE. Decreases to 55% EDE were detected sooner by cumulative sum charts, whereas decreases to 35% EDE were detected earlier by Shewhart charts. Both control charts used together can identify unexpected decreases in EDE more efficiently, thereby minimizing potential economic losses.

Key Words: detection of estrus • statistical process control • economics • dairy

Abbreviation key: ATS = average time to signal, cusum = cumulative sum, EDE = estrus detection efficiency, EDR = estrus detection ratio

This article has been cited by other articles:

				J. M. Lukas, J. K. Reneau, and M. L. Kinsel Predicting Somatic Cell Count Standard Violations Based on Herd's Bulk Tank Somatic Cell Count. Part I: Analyzing Variation J Dairy Sci, January 1, 2008; 91(1): 427 - 432. [Abstract] [Full Text] [PDF]

				J. M. Lukas, J. K. Reneau, C. Munoz-Zanzi, and M. L. Kinsel Predicting Somatic Cell Count Standard Violations Based on Herd's Bulk Tank Somatic Cell Count. Part II: Consistency Index J Dairy Sci, January 1, 2008; 91(1): 433 - 441. [Abstract] [Full Text] [PDF]

				J. M. Lukas, D. M. Hawkins, M. L. Kinsel, and J. K. Reneau Bulk Tank Somatic Cell Counts Analyzed by Statistical Process Control Tools to Identify and Monitor Subclinical Mastitis Incidence J Dairy Sci, November 1, 2005; 88(11): 3944 - 3952. [Abstract] [Full Text] [PDF]