Recipient Organization
PURDUE UNIVERSITY
(N/A)
WEST LAFAYETTE,IN 47907
Performing Department
Veterinary Clinical Sciences
Non Technical Summary
Dairy cattle are responsible for milk production to provide all dairy products for American diets. Cattle are ruminants that have a complex 4-compartment stomach which allows use of high fiber feed. The "fourth stomach" is called the abomasum which is most like the stomach in humans and most other animals. The abomasum has a "J" shape and normally sits near the right ventral body wall. It is attached at both ends but under the influence of abnormal motility and/or gas accumulation it can displace to either side of the abdominal cavity. The left displacement (LDA) is more common than the right-sided displacement. This displacement will cause the cow to be mildly uncomfortable and have a decreased appetite. Secondary to the decreased feed intake is a dramatic decrease in milk production. The full cost of LDA includes the cost of surgical treatment, medical treatment, potential delayed re-breeding and loss of milk production.Surgery of the abomasum appears to be the most common abdominal surgery in dairy practice. It has been reported that some dairy herds experience abomasal displacement in up to 15% of the cows. Left displacement of the abomasum is largely a management disease in that it affects cows, most often in the first few weeks of lactation, that are being fed high concentrate diets to stimulate higher milk production. The full economic impact of abomasal displacement includes treatment of concurrent disease (such as metritis, mastitis and ketosis), treatment of the displacement, loss of milk production, decreased reproductive efficiency and increased culling rates. It is often difficult to fully appreciate the cost of the loss of production because (depending on the degree of illness) the decreased milk production may be present throughout the entire lactation.LDA will continue to have a very important economic impact on the dairy industry and practitioners will continue to make treatment decisions based on economics, the advantages and disadvantages of each treatment option, and the preference for a particular surgical procedure. LDA occurs most commonly in high-producing cows during the first three weeks of lactation.The surgical procedure chosen to correct LDA is commonly based on personal preference and clinician training. There are advantages and disadvantages to each specific procedure. However, there is no scientific proof available that any particular procedure results in fewer complications or increased post-operative production. Another area that has been largely ignored is the effect of duration of disease on post-operative production. In order to formulate correct decision tree analysis equations concerning return on investment in treatment, one must understand which treatment option is best and how duration of disease affects variables in the equation. This then becomes a dynamic method of accurate analysis under the current economic pressures and as well as in the future as changes occur in the economic environment.
Animal Health Component
40%
Research Effort Categories
Basic
40%
Applied
40%
Developmental
20%
Goals / Objectives
Our long-term goal is to develop the economic models that can determine the circumstances that will make it profitable to change the emphasis from LDA treatment to prevention (or at least decreasing the incidence LDA). The steps to achieve that goal are:to determine if pyloro-omentopexy is superior to omentopexy surgical treatment by increasing post-operative productivity in the herd, decreasing reoccurrence of LDA and decreasing post-operative complicationsto determine the impact of LDA treatment on milk production, longevity in the herd and reproductive efficiency
Project Methods
We plan to test our central hypothesis and accomplish the overall objective of this application by pursuing the following research objectives: First we will establish which currently used surgical procedure to correct LDA has the best return on investment. Our working hypothesis is that pyloro-omentopexy yields fewer post-operative complications and results in a longer productive life in the herd than other surgical treatments. Second we will determine how greatly concurrent disease negatively impacts return on investment when treating LDA. Our working hypothesis is that the concurrent diseases often associated with LDA increase post-operative complications and lead to a decrease in milk production during the lactation. Third we will determine how duration of clinical signs prior to surgical correction affects post-operative milk production. Our working hypothesis is that delayed treatment causes decreased milk production for the current lactation as well as future lactations. Fourth we will develop a decision tree analysis model to adequately delineate the economic factors that influence return on investment when faced with a LDA case. The working hypothesis is that, with the current economic environment, surgical treatment of LDA provides a positive return on investment. This is a dynamic result in as much as a change in economic factors in this equation will change the return. There will also be an incidence rate of LDA, which will differ for each herd, at which the overall return on investment for the herd is negatively affected. In this case, management changes to decrease the incidence of LDA will be important. This approach is expected to find that pyloro-omentopexy leads to fewer post-operative complications and greater productive longevity. This is important because it will change the way LDA is treated surgically throughout the dairy industry. Determining the surgical approach to LDA which yields the greatest return on investment for the dairy industry will have a tremendous economic impact on the industry. Determination of negative impacts from delayed treatment of LDA will encourage closer observation by dairymen and earlier correction by practitioners. Additionally, being able to put true costs on the presence of concurrent disease will allow dairymen to make logical decisions on LDA treatment. Collectively, this information will allow construction of decision tree analysis equations that can be applied to each particular dairy operation. This application will allow individual farm managers to determine what incidence rates are acceptable and still profitable to treat surgically as opposed to incidence rates being high enough that significant management changes are in order. Stage One: A retrospective review of medical records of cows from the Purdue University dairy treated for LDA will be reviewed to record the cow age at surgery, most recent date of calving and if the cow was treated by pyloro-omentopexy (PLOM) or omentopexy (OM). The dairy records will also be reviewed to determine reproductive performance based on subsequent lactations and time to calving as well as cull date and reason. The dairy records will be reviewed periodically after the last surgery included in the study and information will be recorded for any cows that had been culled. The final analysis of data will be done after the last cow has left the herd. This work will determine if there is any difference in cows treated by PLOM or OM.Stage Two: The cows treated for LDA from the Purdue University Dairy will be included in a prospective study to evaluate post-operative milk production and reproductive efficiency via days to first post-operative breeding. Time from observation of clinical signs to surgical treatment and any concurrent disease will also be recorded. Each cow treated for LDA will be compared with four control cows having sequential ear tag numbers less than and greater than that of the treatment cow. Daily milk production of each cow will be recorded for the lactation of the LDA. We estimate 10 to 15 LDA cases per year at the Purdue Dairy. If the cows with LDA have a 10% drop in milk production for the lactation, we can have an 80% power to show a significant difference in milk production with 26 LDA cases and 104 control cows. The goal over the time of the study is to have at least 40 LDA cases. We will also record the days to first post-operative breeding as a measure of reproductive efficiency.