Economic Returns from Using Prostaglandin Protocols

Economic Returns from Using Prostaglandin Protocols

Dr. Allen Young

USU Extension Dairy Specialist

Many producers have been using prostaglandin products, such as Lutalyse, for many years as part of a reproductive program aimed at improving efficiency and getting cows bred in a timely manner. However, many producers do not calculate the costs of these program or don't have enough information to determine their worth. Results of a research study published in the Journal of Dairy Science1 can help evaluate the economics of these programs.

Researchers at Cornell University calculated the economic relationship between several different protocols using a reproductive simulation program they developed. The simulation was conducted using a 500-cow herd size and extended to a 10-year period to reach equilibrium. At this point the herd was simulated for another 2 years using either the same parameters as in the base period (control) or with each of the protocols listed below. Only the data on the net return per cow per year are shown. Other measures of reproductive performance such as Days Open, Days to First Service, number of reproductive culls, and sensitivity analysis of costs associated with rectal palpations, milk progesterone test, and labor costs were also computed, but are not shown.

Prostaglandin Protocols

Each treatment had the same estrus detection efficiency for the 1st week after PGF2 injection, but was computed with or without heat detection during the second week after injection. An additional fixed time treatment was computed using values for a best case scenario. The three treatments were as follows:

1. Administer PGF2 based on presence of CL diagnosed by rectal palpation (RP);

2. Administer PGF2 based on presence of CL diagnosed by a milk progesterone test;

3. Administer PGF2 based on a fixed treatment schedule (i.e., every 14 days) without screening for ovarian status.

The net returns per cow per year for each of the treatments are shown in Table 1.

Table 1. Net return per cow per year for different prostaglandin protocols considering average price levels. The differences are relative to control herds with a baseline estrus detection efficiency (EDE) of 35, 55, and 75%. The values that are in bold print indicate the highest return for the level of EDE.

Protocol EDE2 EDE
Week 1Week 235%55 %75 %
Rectal palpation 7535$4.62$2.49$1.15
Rectal palpation 7504.751.540.54
Milk progesterone test 75353.631.830.62
Milk progesterone test 7503.911.550.49
Fixed treatment schedule 85554.963.383.19
Fixed treatment schedule 75355.843.471.66
Fixed treatment schedule 7507.022.690.74

2Estrus detection efficiencies for the 1st and 2nd week after treatment.

The results suggest that:

a) Any of the prostaglandin protocols considered would result in an increased net return per cow over not having a prostaglandin protocol. However, the magnitude of the net return was highest for those herds that used a Fixed Treatment Schedule.

b) The benefit of a prostaglandin protocol increased as EDE decreased and decreased as EDE increased.

c) In a herd with low estrus detection efficiency (35%), continuing heat detection during the second week after start of the protocol may be economically beneficial; however, it was not cost effective with higher EDE (55% or above). The major factor which determines the economic benefit is the cost of labor; the break-even level being about $10 per hour for an EDE of 35%.

d) Finally, the time required to evaluate the benefits of these programs was about 12 months.

The take-home message is that prostaglandin protocols are cost effective, especially if EDE is low. As EDE improves, the cost benefits decrease, but are still above control, especially if you are using Fixed Treatment Schedules (highest returns of all).

If you have questions regarding this article, feel free to contact me at (435) 797-3763 or e-mail at


1Journal of Dairy Science 80(11): 2766 (1997).