Pregnancy Detection
Economics of Pregnancy Testing Beef Cattle Model
Assuming a spring calving schedule, generally producers have three options for managing open cows:
- Preg-check and cull non-pregnant cows in the fall.
- Preg-check in the fall and feed non-pregnant cows separately to market at a later date.
- 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 | Economic costs to consider | Economic gains to consider | Economic costs to consider |
| Avoid overwintering costs for non-pregnant cows. | Vet cost of preg-checking herd. | Value of fed cull cows in the spring realized. | Supplemental feed cost. |
| Value of non-pregnant cows in the fall realized. | Value of fed cull cows in the spring forgone. | 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:
- Basic Model - requires only six pieces of information: herd size, type of management system, the month preg-checking will occur, the anticipated calving month, and the current fall month and market price.
- Advanced Model - allows producers to enter custom data for their herd including: cost of production, ADG, length of winter feeding period, herd open rate, and veterinary cost to more accurately calculate the net gain or loss of preg-checking.
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:
- Gain/head = {(Overwintering cost + value of cow in fall - value of cow in spring) x herd open rate} - Vet cost
- Overwintering cost = daily cost of production x days in winter feeding period
- Value of cow in fall = fall weight x fall market price
- 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)
