Field Study Of Displaced Abomasums

For some dairy producers, displaced abomasums (DAs) have become a problem of epidemic portions. Over the years, many researchers have conducted studies regarding the cause, prevalence, incidence, risk factors, and economic impact. The causes of DAs are believed to be metabolic disturbances, lactational stress, and nutritional disorders. The objectives of this study were to analyze how many dairy producers had a DA percentage of over five percent, how many cows with DAs recovered after treatment, and how many cows with DAs were culled or died. Correlations between feed additives and the number of DAs, economic losses of DAs, and the prevalence of DAs were also estimated.

The survey consisted of twenty-four questions which inquired about the dairy producers herd size, number of displaced abomasums in the herd, management practices, and observations concerning cows with displaced abomasums between January of 2003 and January of 2004. In February of 2004, this survey was mailed to one hundred and seventy-six dairy producers in three Illinois counties- Bond, Clinton, and Madison. The response to this survey was forty percent. This survey involved eight thousand four hundred and seventeen dairy cows from sixty-seven dairy herds. The results were statistically analyzed using the SAS program and Microsoft Excel.

About four percent of all the cows in herds that were surveyed developed a DA. Thirty percent of the respondents had a DA percentage of over five percent. In this study, seventy-nine percent of the abomasum displacements were left-sided (LDAs) and twenty-one percent were right-sided (RDAs). Six percent of the dairy cows in this survey had re-occurring DAs. Dairy producers reported that DAs were most prevalent during their cow's first lactation (thirty-eight percent). Fifty-one percent of the dairy producers in this survey observed that their cows with DAs exhibited associate conditions. Retained placentas (thirty percent), ketosis (twenty-eight percent), and low milk yield (twenty-one percent) were the three most frequently noted associated conditions of DAs.

This survey discovered that dairy producers who used propylene glycol as a feed additive in their fresh cow rations slightly increased the risk of DAs in large herds. Seventy-nine percent of the cows with DAs in this survey recovered after treatment (Figure 1). Only thirteen percent of the cows with DAs were culled and nine percent died. Statistical analysis of the results of this survey revealed that fifty-four percent of the dairy producers stated that the production rates of their cows with DAs were adversely affected. A loss in milk production in cows with DAs was consistent with other studies . The Eighth Edition of Veterinary Medicine reported that eighty percent of cows with LDAs produced 550 to 1100 pounds less milk during the lactation with displacement and that approximately ten percent of cows with displacement produced at least 4405 pounds less milk than expected. The surgery to correct displaced abomasums costs an estimated $250.00 per occurrence. Figure 2 estimates the economic losses that dairy producers should anticipate due to DAs with a range of $305 to $690 per incident.

Take Home Messages

• Fresh cows in large herds that were fed propylene glycol as a feed additive were at a slightly increased risk of developing a displaced abomasum.



• The prevalence and incidence of displaced abomasums in the three Illinois counties was four percent.



• Seventy-nine percent of the cows that developed a displaced abomasum recovered after treatment, thirteen percent were culled, and nine percent died due to complications.



• The average economic loss (milk losses/veterinary expenses) for cows that develop a displaced abomasum can range from $305 to $690 per incident.



• Thirty percent of the dairy producers in this survey had a DA percentage of over five percent.