Pregnancy Detection Tool

Pregnancy Detection

The Economics of Pregnancy Testing Beef Cattle Calculator is based on the economics of preg-checking model which was developed by Ben-Ezra and Muzzin in 2015. It can help cow-calf producers make the most economical decisions for their operation.

Economics of Pregnancy Testing Beef Cattle Model

Assuming a spring calving schedule, generally producers have three options for managing open cows:

  1. Preg-check and cull non-pregnant cows in the fall.
  2. Preg-check in the fall and feed non-pregnant cows separately to market at a later date.
  3. Do not preg-check – overwinter all cows and cull opens in the spring after calving.

  Preg-check in fall and cull immediately Preg-check in fall and feed cull cows separately until spring
Economic gains to consider Avoid overwintering costs for non-pregnant cows.

Value of non-pregnant cows in the fall realized.

 Value of fed cull cows in the spring realized.
Economic costs to consider Vet cost of preg-checking herd.

Value of fed cull cows in the spring forgone.

 Supplemental feed cost.

Value of non-pregnant cows in the fall forgone.

Vet cost of preg-checking herd.

To help producers choose the most economical option for their operation, the Economics of Pregnancy Testing Beef Cattle Model calculates the gain or loss per head of cattle when preg-checking and culling open cows in the fall compared to overwintering and culling in the spring. It is important to note that in the model the gain/loss per head applies to all cows in the herd, both those that are pregnant and non-pregnant. This model was designed in this fashion because the decision to preg-check must be made before the herd pregnancy rate is known.

There are two variations of the model:

  1. Advanced Model (recommended) – This version allows producers to enter custom data for their herd including cost of production, ADG, length of winter-feeding period, herd open rate and vet cost to more accurately calculate the net gain or loss of preg-checking.
  2. Basic Model – This version uses default values for herd management data such as length of winter-feeding period, average daily gain, vet cost for preg-checking and open rate. Overwintering cost of production can be selected based on different management systems. Due to on-farm variation, producers looking for customized information may use the Advanced model.

Feeding cull cows – Both models have the option to enter parameters for feeding cull cows as a separate group. By entering feed and overhead cost, the expected number of days on feed, and the expected average daily gain (ADG) of cows in the group, the model will calculated the expected gain or loss of preg-checking in the fall and feeding cull cows as a separate group.

The models use the following formula to determine the net benefit of preg-checking and culling in the fall:

  1. Gain/head = {(Overwintering cost + value of cow in fall – value of cow in spring) x herd open rate} – Vet cost
  2. Overwintering cost = daily cost of production x days in winter feeding period
  3. Value of cow in fall = fall weight x fall market price
  4. Value of cow in spring ={fall weight + (average daily gain over winter x days in winter feeding period)} x spring market price

More information is available in the Canfax Research Services fact sheet: The Economics of Preg-checking (April 2017)

Advanced Model
Basic Model

PART A – PRODUCER INFORMATION

Enter your information in the yellow highlighted cells below.

Section 1 – Basic Information
Factors Additional Information
Herd Size

Enter number of cows and first-calf heifers.
Management System

A = drylot; B = swathed barley in part of winter feeding; C = bale grazing; D = standing corn grazing
Expected month of preg-checking

A=September; B=October; C=November
Anticipated calving month

A=February; B=March; C=April; D=May
Current fall cull-cow market price (CAN$/lbs))

Enter the current fall market price for the cull cows in Canadian dollars per pound
Enter the month for the price above

A=September; B=October; C=November

Section 2 – Herd Management Data
Factors Additional Information
Cost of production ($/cow/day)

Enter the cost of production per cow per day to maintain a cow over winter, based on your production system (include feed and overhead costs)
Length of winter period (days)

Average for Western Canada = 160

ADG (lbs/day)

Average Daily Gain, per cow
Vet cost for preg-checking one cow

Enter the cost charged by your veterinarian to preg-check one cow
Herd open rate

Percentage of herd that is open in the fall (average for Western Canada = 7.7%)

Section 2 – Cull Cows Fed as Separate Group for Better Gains

Section 3 – Cull Cows Fed as Separate Group for Better Gains
Factors Additional Information
Estimated number of cull cows

Calculated from the herd size and assumes a herd open rate of 7.7%
Number of days on feed

Total days that cull cows are separated and fed until marketed (may enter between 1 and 350 days)
Month cull cows marketed

Calculated using month preg checked and number of days on feed
Estimated cull-cow price at marketing ($)

Estimated based on the month from above
Feed and overhead cost ($/cow/day)

Enter the cost per cow per day for feeding a cow for improved gains. This may be different than your cost of production to maintain a cow over winter.
ADG (lbs/day)

Average Daily Gain per head you expect to attain for the group

Section 3 – Management Factors When Not Fed Separately (From Management System Selected in Section 1)

Section 4 – Management Factors When Not Fed Separately
Cost of production ($/day/head) Winter feeding period (days) ADG (lbs) Total gain over winter (lbs/cow)

Section 4 – Cull Cow Value When Not Fed Separately

Section 5A – Cull Cow Value When Not Fed Separately
Value of cow in October Value of cow in March Difference

Section 5 – Cull Cow Value when fed separately

Section 5B – Cull Cow Value when fed separately
Value of separately fed cow in March Value of cow in March Difference

PART B – ECONOMIC MODEL RESULTS

Do not preg-check (cull in spring) Preg-check in fall and cull immediately Preg-check in fall and feed cull cows separately until spring
Gain/head Gain/head Gain/head
Gain for herd Gain for herd Gain for herd

PART C – ECONOMIC MODEL DATA

Section 1 – Management Factors
Management System Cost of Production ($/cow/day) Winter feeding period (days) ADG (lbs/day) Total gain over winter (lbs) Vet cost ($) Average herd open rate (%)
Drylot
Swathed barley grazing in part of winter feeding
Bale grazing
Standing corn grazing
Producer custom data (based on entries from Part A, Section 2)

Section 2 – Market Factors
Month Historic average price (CAN$/lbs) Projected price based on known September price (CAN$/lbs) Projected price based on known October price (CAN$/lbs) Projected price based on known November price (CAN$/lbs) Average Live Weight (lbs) Value
September
October
November
December
January
February
March
April
May
June
July
August

Section 3 – Veterinary Cost and Open Rate
Average vet cost of preg check/cow ($) Average herd open rate

Section 4 – Veterinary Cost and Open Rate
Month Monthly Averages from 2013-2022 (CAN$/cwt) Percent change based on September market price Percent change based on October market price Percent change based on November market price
September
October
November
December
January
February
March
April
May
June
July
August

Section 5 – Cull Cow Separate Group Data
Weight of cull cow after feed Day cull cow was separated Day cull cow was marketed