What criteria do you use when making elective culling or breeding decisions? Production level, reproductive status, age, conformation, history of health events, and opinions likely guide your decisions for better or worse. The COWVAL module in Dairy Comp 305 is a tool that can help augment daily management decisions for individual cows by providing an objective calculation based on industry-level economics, herd performance, and individual cow performance data. 

At the heart of the module are several key concepts that make COWVAL workable; the dairy should be running at full capacity, animal-level decision-making should improve the herd’s profitability, and less profitable animals should be replaced with more profitable animals.

While these basic tenets of cow management seem intuitive, the module takes into account economic factors such as milk price, time-value of money, replacement costs, cull prices, and feed prices. Herd- and cow-level information are also integrated into the program’s algorithms including heat detection rate, conception rate, reproductive status, age, production level, and stage of lactation. Once the module crunches all the numbers a numeric value, identified by the item CWVAL, is assigned to each animal quantifying its current monetary value compared to a fresh heifer within the herd. A pregnancy value is also calculated to aid in making breeding decisions; an open cow (usually) becomes more profitable by the indicated PGVAL value when diagnosed pregnant.

Essentially, a positive value indicates that the cow is worth more than a fresh heifer and a negative value suggests the cow should be replaced, assuming the farm is operating at an ideal stocking density. While the logic of the module is sound, calculations are based on data such as test day milk weights or daily milk weights. Caution must be exercised whenever data-based decisions are made – faulty meters, cows less than 60 DIM, and health events (mastitis, lameness, etc.) temporarily reducing production can all falsely decrease CWVAL and lead to incorrect decision-making. The module attempts to model the future performance based on current and historical data so assumptions are made in the calculations.

Using CWVA or PGVAL to help make culling or breeding decisions can help improve the profitability of a dairy as long as other cow-side factors are considered. Add these items to your vet check list and cull candidate list to augment your decisions. Search the DC305 manual for additional module information and to find instructions on how to initialize the module.