Look at the photo on this page — yes, the one of cattle carcasses hanging on a rail at a meatpacking plant. You will note the obvious difference in color, owing to the accumulation of yellow fat versus white fat.
Cows with yellow fat have been on a high-forage diet instead of one that's high in concentrate. Specifically, the yellowing occurs from high beta-carotene levels in alfalfa and grass-type silage.
Yellow-fat carcasses and the cuts that come from them are not especially appealing to consumers. Certainly, yellow fat makes the meat appear older — and perhaps not as healthy — as meat with white fat around it.
Here are some ideas for finishing out cull dairy cows on a high-concentrate diet before they go to slaughter, therefore showing your responsibility as a meat producer, in addition to a milk producer, and also qualifying for packer premiums.
60 to 90 days
In some cases, cull dairy cows already have white fat upon dry off, says Jason Ahola, beef cattle extension specialist at the University of Idaho. Yet, a majority has yellow fat and needs some finishing in order to make the conversion to white fat. The objective is to get cows into a white-cow grade at the meatpacker.
In many cases, you can switch a cow to a white grade in 60 to 90 days if the cow is on a high-concentrate diet.
In a study conducted by Cornell University four to five years ago, 40 percent of dairy cull cows achieved a white grade after 70 days of ad libitum feeding with a high-concentrate diet. The diet had a concentrate level of about 62 percent and a metabolizable energy level of 1.2 Mcals per pound of dry matter.
Feeding to 90 days would have upped the percentage of white-grade cows even more.
How fast you achieve a white grade will depend in large part upon the energy level of the diet, points out Mike Baker, beef cattle extension specialist at Cornell University. With a high-grain diet, it may take 70 days, but when the diet consists of both grain and forage, as in the case of corn silage, it may take 100 days or more.
Baker suggests having a metabolizable energy level of 1.2 to 1.3 Mcals per pound of dry matter - comparable to the energy level for highly productive lactating dairy cows.
Feeding a high-energy diet won't be cheap, especially with today's feed costs. So, it is important to pencil out the costs in comparison to the potential advantages that come with a white-cow grade.
Any combination of economical energy sources can work to feed out cull dairy cows; it doesn't have to be grain necessarily. For instance, in New York State, many producers feed distillers grains if they live in proximity to ethanol plants, or else make use of bakery by-products. In northwestern states such as Idaho, many people use potato byproducts for feedlot cattle, but potato byproducts can certainly be used for cull dairy cows as well, points out Ahola.
Both Baker and Ahola cite the possibility of using refusal or left-over feed from the main lactating herd.
Work with your nutritionist to see if you can capture the advantages of a larger, finished-out carcass at slaughter and also one that earns a premium for falling into a white grade at the meatpacking company.