When WCS is a particularly good buy, a reasonable question is: how much can one feed?
Most dairy producers in the South and West feed from 5 to 8 lb. per cow per day. This is about 15% of the total diet dry matter in a TMR. But if fed for extended periods (more than 6 months), producers need to be aware of the safe levels of a compound called gossypol.
Research conducted at Auburn University suggests that 24 grams of free gossypol is the approximate upper limit for the lactating cow, allowing up to 10 lbs. of WCS per cow per day if the free gossypol is 0.50% or less in the whole seed (22.7 grams). A gossypol analysis is recommended to determine the exact amount of free gossypol if feeding more than 8 lb. of WCS per cow per day.
Analyses are usually expressed as a percentage of the kernel (meal plus oil); to convert the percentage of gossypol in the kernel to the percentage present in the whole seed, multiply by .68. For example, if a kernel contains 0.92% gossypol, the equivalent amount in the whole seed would be 0.63%. If cottonseed meal and/or cottonseed hulls are also being fed, their contribution to the total free gossypol intake needs to be included also, though they may have much less free gossypol than WCS.
Whole cottonseed, as with many other feedstuffs, may have problems with aflatoxin produced by molds, developed in either the field or from poor storage of the cottonseed. Purchasing agreements should state clearly that the WCS have less than some specific amount of aflatoxin (20 ppb is the legal limit for feeds used in dairy rations). Storing WCS on a well-drained pad protected from rain is a necessity.