Heifer Breeding Soundness Exam (BSE)
Practices that minimize costs on the beef cattle operation are considered to be the most important components of successful long-term management. Any service or product that can improve efficiency or longevity of animals or equipment should be fully utilized by the progressive producer. The concept of cost mitigation often falls victim to the thought-line that not spending money is equivalent to minimizing costs. However, that could not be further any further from the truth!
My dad was the ultimate thift-ster: if it could be patched or lashed or painted, the object in question could be considered as good as new. Growing up around him taught me the value of taking care of what you have and being proud of it. I also learned to take pride in our ability to be resilient and resourceful. Something else my dad was really good at, though, was knowing when to wisely spend money to get something that would return on his investment. When something needed to be purchased, he would research what was available, consider what we needed, and buy quality. I cannot think of a single time when he ever picked the cheapest product in the lineup simply for that reason alone. If he did, I’m sure it quickly got thrown aside, cussed, and replaced.
This story relates, in my mind, to the relationship I encourage producers to have with their replacement heifers. Recognize the quality that you have, back that subjective opinion up with an objective third-party evaluation of production traits, and spend the money to replace with better quality if need be. According to 2007 USDA NAHMS survey responses, 98% of beef operations retained heifers from their own herds as replacements for cull breeding cows. In that same dataset, less than 4% of respondents indicated that they do any screening to assess calving ability of the animals they keep. If a respondent had 50 cows or less, only 1.5% reported performing heifer breeding soundness exams. If the producer had 200+ cows the number jumped up to 16%, which in my opinion is still miserably low.
The heifer breeding soundness exam, much like the counterpart exam on the bull, is both important for the economics of the farm and for the welfare of the animal. The exam should include evaluation of the animal’s appearance and attitude. Does she have the right colored hide for your market? Does she have good muscling ability and frame size, comparable to other successful animals in your herd? Does she have solid feet and legs that will carry her for years to come? Does she want to be a member of your herd (in other words, is she docile and reasonable during handling)? These evaluations are most often done by the producer before and after weaning, but should be continuously evaluated as the animal grows. Beyond her outer appearance, the heifer should also be assessed for most likely producing ability. With an unproven animal, all we have to rely on for this prediction is the production history of her dam and sire. With registered animals, we can evaluate Expected Progeny Differences, or EPDs, to get an idea of what this animal offers. In commercial heifers, we can do a similar evaluation if the farm has maintained records of calf weights and dam performance. Birth weights, weaning weights, dam body condition and/or weights, calving dates are relatively simply data to collect and maintain for a cow herd, and should be followed annually. Producers should put more weight on selecting heifers born early in the calving season, if a controlled breeding and calving season is followed on the farm as these heifers are more likely to be regularly cycling and of appropriate weight by their first breeding season. One could also argue that these first-born heifers are the progeny of more highly fertile cows that bred early in the season while nursing younger calves.
When the heifer reaches 12-13 months of age she should be evaluated by a veterinarian for several criteria. The heifer BSE should include measurement of the pelvic canal, palpation and grading of the heifer’s uterus and ovaries (called a reproductive tract score), weight and body condition score, docility score, and hip height. All of these numbers can be evaluated in relation to the herd’s average mature cow size, average calf birth weight, and marketing goals of the producer, and aid in the selection of the most likely to be productive animals available in the heifer pool.
Culling heifers with inappropriate pelvic areas removes those outlier individuals that don’t fit with the herd. Heifers with too small a pelvis to successfully deliver a calf unassisted should not be kept for welfare reasons. Similarly, heifers with pelvic areas much larger than average will likely become oversized cows that are unlikely to be efficient herd-members. Defining that number is somewhat arbitrary farm to farm, but a generally accepted minimum number is 140 cm2 for a Bos taurus heifer. Reproductive tract scores (RTS) are important in that they identify animals that are not sexually mature close to the beginning of desired breeding time.
Animals that are mature and cycling before the breeding season starts are more likely to get pregnant quickly and have higher fertility for the rest of their productive lives than do heifers who are not as mature. Cut-off points for reproductive tract scores will again vary by farm and are highly situationally dependent. Certainly, animals that are sexually immature or identified as not reproductively sound on palpation should be culled from the replacement heifer group. In a 2014 publication by Holm et al, final pregnancy rate for RTS5 heifers was 93% compared to 76% for RTS 2 heifers, with 80% of the RTS 5 heifers conceiving to AI at the start of breeding cycle and only 40% of RTS 2 heifers conceiving to timed AI. Calves born to the RTS 5 heifers weighed 60 pounds heavier than did those born to RTS2 heifers as they were 34 days older at weaning. Interestingly, in the subsequent breeding season, 80% of RTS5 heifers conceived to timed AI as a lactating 2-year old while only 61% of RTS2 heifers did so.
These measurements are simple to collect and evaluate. When I perform these exams, I will often make management recommendations with the animal still in the chute so she can be segregated from the breeding group simultaneous to the exam. There are situations where I like to go back to the office and compile data in a spreadsheet to really evaluate the group as a whole and figure out what the best recommendations for my client should be. This can be a great opportunity to engage with your herd veterinarian and truly get the benefit of the veterinary-client-patient relationship. Working together, you should be able to weed out less than productive females and improve the health and welfare of your reproductive herd accordingly.
Others opportunities that can be considered at the heifer breeding soundness exam include: preventative pre-breeding maintenance (immunization boosters, trace mineral supplementation, parasite evaluation), surveillance screening for diseases of concern such as BVD, sampling for DNA/genomic evaluation, bull selection, and running economics of retaining heifer calves compared to purchasing replacements.
As compared to bull evaluation pre-breeding, heifer evaluation can be much more complex. To be fair, I believe that it should be a much more meticulously considered endeavor for the producer. A heifer retained at weaning is potentially going to be an animal you tend to for 8-10 years, if you made a good decision. The costs associated with 2 and 3 year olds not breeding or 5-year old cows falling out of production due to inefficiency or bad structure is much more detrimental to the overall herd portfolio than is the cost of critically evaluating heifers early in production.