It is that time of year on Grant Ranch, where we sort off the cull cows for sale. Culling is the process of marketing older, unproductive and open cows.
Older cows that have consistently had a calf may be culled as they are at a higher risk of being structurally unsound or having health concerns. Structurally unsoundness includes: teeth inadequate for grazing, poor udder or lameness. Health concerns include diseases like cancer eye or cervical prolapse that has been treated but has a high probability to repeat. It is better to ship these older cows while they are in decent condition. Some cows should not be shipped under any conditions, the Beef Cattle Research Council outlines them here.
A cow may be considered unproductive for a number of reasons. First, she may be open, that is she does not have a calf. Second, her calf maybe of poor quality (e.g. a runt) as they have focused on maintenance rather than providing milk for the calf. Third, she may be high maintenance. That is she requires extra labour during the calving season. These high maintenance cows can be hard to find when it comes time to wean and cull; hence we try to tag them at the time they are handled so that we can identify them later in the year. Right now we are only shipping the open cows as the unproductive and older cows that have calves on them will be culled after the calves have been weaned.
While we preg-check our bred heifers in the fall and sell anything that is open at that point, we do not preg-check our mature cows. Open cows are identified after calving. The first time a cow is open, she stays in the herd (if she is young) and gets a second chance. This is the case with the cow in the below photo, we know that because her left ear has been trimmed, so we will know when she is open a second time. While many advocate selling all open cows, the cost of replacing a young open cow tends to be higher than keeping her. By selling in August we tend to hit the high in the cow market and have additional pounds on these cows.
It is rare, but in cases where a cow has been treated for some reason, we have double checked withdrawal times of the product used. This is the period of time that must pass between the last treatment date and when the animal can be slaughtered or milk used for human consumption. These withdrawal times can range from 0-60 days or more. All federally approved drugs provide the withdrawal time on the product label or package insert.