Ultrasonography has been used since the mid-1990s to detect violations of dairy show codes of ethics.¹ Originally used to detect gas infused into the udder to approve udder appearance,² ultrasonography has subsequently proven useful for detecting and quantifying a variety of injected substances, effectively eliminating these types of unethical injections from most dairy shows.³ However, although use of prolonged (≥ 24 hours) nonmilking intervals (ie, over bagging) to artificially improve udder size and appearance has been on the list of forbidden practices in the codes of ethics for many major dairy shows for > 20 years,¹ violations have not been consistently enforced worldwide.

Many violations of dairy show codes of ethics are cosmetic and medically unimportant to cows. However, over bagging has been proven to cause stress in and adversely affect the health of cows. A recent study,⁴ for example, that measured various factors during a prolonged (24-hour) period of nonmilking in Holstein dairy cows found that the cows' health and well-being were compromised by even this single prolonged nonmilking interval. The behavior of the study cows was changed (eg, decreased eating time and increased ruminating time and hind limb abduction), and various abnormalities were detected, including edema in subcutaneous udder tissues, increased milk leakage, and high somatic cell counts in the milk. Importantly, udder edema was a late change that was seen only after other indicators of stress and pain had been evident for many hours.⁴

At 2 large international dairy shows I attended in 2015 and 2016, I personally observed a 50% increase in the overall prevalence of over bagging from one year to the next, with my findings independently corroborated by internationally recognized experts in ultrasonography of the udder who also attended these shows. Similar trends have been described by others at multiple large international shows, including shows in the United States, Canada, Australia, and Europe. For the 2 shows I attended and 4 other international shows, the prevalence of over bagging, as determined by ultrasonographic examination, ranged from 10% to 90%, with prevalence of the most severe grades of over bagging (ie, a grade of 3 or 4 on a scale from 0 to 4; Figure 1) ranging from 0% to 60%. The prevalence did not appear to be dependent on age of the cows, and over bagging was detected in all age groups. However, it did appear to be dependent on the breed of the cows, in that even though over bagging was detected in all breeds exhibited at these shows, Holsteins appeared to be overrepresented in regards to overall prevalence and prevalence of the most severe grades of over bagging. At one international show, the red-and-white grand champion had the most severe form of edema, resulting in complete loss of the udder crease.

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Ultrasonographic images of the forequarters of the udder in 2 dairy cows, illustrating the appearance of the normal subcutaneous space (A) and the appearance of the subcutaneous space in a cow with moderate-to-severe (grade 3) edema (B). In the cow with udder edema, notice the alternating thin hyperechoic and hypoechoic lines. White lines on the right side of each image indicate depth (cm) from the skin surface.

Citation: Journal of the American Veterinary Medical Association 251, 3; 10.2460/javma.251.3.271

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The effectiveness of ultrasonography and milk testing in detecting other forms of unethical udder augmentation has seemingly encouraged exhibitors to prolong the nonmilking interval to maximize the size of the udder. However, this comes at the expense of cow stress and suffering. Informal discussions I have had with numerous exhibitors indicated that this was a procedure they did not want to perform on their cows but felt was necessary to be competitive. These owners admitted to withholding milking for 24 to 36 hours to obtain the desired appearance.

Dairy show officials are looking to veterinarians for guidance on these types of issues. However, there does not appear to be an overwhelming commitment among most veterinary officials at dairy shows to recommend eliminating this form of udder augmentation. Given current research findings and the apparent increases in overall prevalence of over bagging and prevalence of the most severe grades of over bagging, it seems that now is an opportune time to take a more aggressive stance against this practice. To not do so would seem to risk allowing the problem to get even worse, risking medical concerns for affected cows and public relations issues for dairy shows and the entire dairy industry.

I recommend that, subject to an appropriate phase-in period, over bagging be enforced as an ethics code violation, with the same punishments used for other ethical violations. Ultrasonography is a sensitive method for identifying edema and can differentiate between over bagging and other forms of edema in dairy show cows.⁵ Edema appears as alternating hyperechoic and hypoechoic parallel lines in the subcutaneous space (Figure 1), and the severity of the edema can be graded on the basis of the number and depth of the lines. Failure of the dairy industry, and veterinarians supporting that industry, to act will inevitably result in a public relations issue that will draw the attention of the media, animal welfare groups, and the government. Adoption of appropriate monitoring and enforcement protocols, however, will maintain the wholesomeness and integrity of dairy shows.