Considering the rising cost of feed associated with maintaining a cow through the winter, removing non-pregnant cows from the herd prior to winter would seem to be an efficiency no-brainer. But the National Animal Health Monitoring System (NAHMS) indicates that fewer than 20% of beef producers diagnose pregnancy in their cattle on an annual basis.
If you're among that 80+% not performing pregnancy diagnosis as an annual ritual in your herd, let's examine how many winter-feeding dollars you could be wasting to maintain open females through the 5- to 7-month winter-feeding period. Our basis will be a 200-head operation with at least a 90% pregnancy rate after a 65-day breeding season. If 10% of your females are open and hay is valued at $160/ton, you're paying more than $11,000 to feed nonproductive cattle (Table 1).
The bottom line is every non-pregnant cow in your herd during winter is stealing money from your beef business. That's money that can be better spent on properly feeding cows that are pregnant and producing a marketable product for the following year.
The average cost for pregnancy diagnosis is around $5-$6/head, but the payoff can result in thousands of dollars more in profit. Plus, pregnancy diagnosis also allows you to make critical management and economic decisions several months prior to calving.
For instance, besides cutting winter-feed costs, pregnancy diagnosis enables you to estimate the age of the fetus and likely calving date. This data can help identify late-calving cows that may need to be culled from the herd in order to minimize the length of your calving season. The calving spread can be quickly reduced if these cows are replaced with heifers that conceived early.
Meanwhile, groups of animals with low pregnancy rates may indicate problems with an individual bull, the presence of an infectious disease or possibly inadequate nutrition prior to mating.
This nutritional status can be most easily determined by evaluating the body condition of each cow. A nine-point scale has been successfully used by beef producers for many years. For instance, a body condition score (BCS) of one is extremely thin, while a BCS of nine is extremely fat and obese. An adult cow in optimal body condition should have a BCS of 5-6 before calving.
Research shows cows in a borderline body condition (BCS of 4 or less) have greatly reduced pregnancy rates, increased calving intervals and lower calf daily gain. Meanwhile, extremely over-conditioned cows (BCS 8-9) are more costly to maintain and more prone to calving difficulties.
Therefore, overweight, underweight or open cattle can greatly reduce your yearly income. Instituting pregnancy diagnosis and BCS systems into your herd-management plan enables you to make important decisions regarding production efficiency and can also greatly increase your profit margin.
Generally, the most convenient time for pregnancy diagnosis can be organized easily to coincide with the fall vaccination schedules or weaning dates. Pregnancy diagnosis is usually carried out 6-8 weeks after the bulls have been removed. Non-pregnant cows can be recorded using their ID numbers. These cows can then be segregated and prepared for sale after weaning.
Pregnancy diagnosis offers many more benefits than those discussed here. Most importantly, checking the pregnancy status of your cowherd allows you to make timely culling decisions and focus your resources on the sound, reliable breeders in the herd. In today's cattle economy of rising inputs and value-added marketing, that can translate into big savings and additional profit.
Whitney Camp is a fourth-year student in Purdue University's School of Veterinary Medicine in West Lafayette, IN.
Get 'Em Gone 
|Winter feed costs (hay price/ton)|
|*Not cost effective to pregnancy testing |
Source: Purdue University School of Veterinary Medicine, West Lafayette, IN.