Right about now many people will be weaning spring calves. Autumn also seems to be a good time for producers to walk through their herds and start thinking about which cows to keep and which ones to cull. The important decision to replace cows can mean more than just getting rid of open females. Rather, producers should review their post-culling options to learn which ones work best to generate better cowherd revenue.
Mature cows and replacement heifers are culled for several reasons, but removing open cows and problem breeders should top everyone s list.
After all, good reproductive performance is the true lifeblood of generating annual cow-calf profits. Economics of most profitable beef operations revolves around getting all cows pregnant by 80-90 days after calving, so that each drops a calf at about the same time every year. Straggler cows that routinely breed/calve outside of a controlled season are often good cull candidates. They re out of sync with optimum reproductive goals such as a perennial short breeding/calving season, which generates more marketable, uniform-sized calves with heavier weaning weights.
One should also realize that even a top-notch herd s best cows are eventually culled.
A recent Florida study demonstrated that sound healthy and fertile cows have an economically viable reproductive life of about eight years, but overall fertility slips by 10 years, and steeply declines after the cow becomes 12 years or older. Furthermore, as young cows become old cows, their bodies slowly break down; teeth become worn and periodic digestive upsets take their toll on nutrient uptake. Teats and udder structures (milk production) collapse, uterine disorders increase and repeat themselves and lameness problems seem to multiple. Furthermore, as cows become significantly older, they tend to become more susceptible to various infections and disease.
Cows that are no longer economically viable to a cow-calf operation may be culled at any time. The general rule is cows with serious disease and health problems such as cancer, persistent digestive disorders, advanced lameness or contagious diseases should be culled immediately. Confirmed infertile cows (i. e. returns to estrus, palpitation or ultrasound), which are healthy and may still be milking after the breeding season might be kept until after their calves are weaned. At this time, all cull-mates should be grouped together and the decision made to either sell now or put them into drylot for further feeding and subsequent marketing.
The option to retain and put additional body weight on cull cows tends to be a modest opportunity to improve their basic economic salvage value. Various American field studies have demonstrated that cull cows will gain both lean and fat tissue mass in about the first 30 to 60 days after they re introduced to a high-energy diet. After 60 days, the same cows will likely lay down only body fat and desired average daily gains will decline.
The general conscience generated from American cull-feeding trials is that young, healthy females in thin to modest body condition are the best cull candidates for post-breeding or post-weaning feeding. Realized average daily gains ranged from 1.5 lb./head/d on a diet of cornstalks and other crop residues to up to three lb./head/d on a corn silage/corn grain supplemented diet. Therefore, corresponding feed efficiencies tended to be around 10 lb. and up to 7.5 lb. of feed per lb. of gain, which depended on the diet, duration of feeding and age/ condition of the culled cows.
Most people experienced with feeding cull beef cows usually accept that feeding these animals, even the most nutritious and balanced diets produce lower feed efficiencies compared to feeding younger, more marketable beef animals. Part of the underlying reality of feeding cull cows is that not all are uniform in age, body stature, and health or have the same growth potential to generate income. Usually, it s a practical matter of grouping all available culls together (as recommended above) in order to put a couple to a few hundred pounds of body weight on each cow, before sold as a group.
Typical cull cow rations can be very straightforward. A sample Canadian cull-cow diet fed to 500- 600 kg cattle for 30-60 days on an as fed basis might include:
” -13.0 kg of barley silage
” 1.0 kg of alfalfa-grass hay
” 8.0 kg of dry-rolled barley
” 0.1 kg of premix
When putting cull cows on a high-energy feeding program for one to two months, a profitable margin should calculated beforehand. Producers should have a good idea of all feed prices as well as the seasonality and magnitude of cull cow prices, and proposed sale date. Yardage, trucking and other non-feed costs (re: medications) should also be pencilled into the spreadsheet. In addition, producers will need appropriate facilitates for a pen of cull cows, segregated from the main cow herd.
Despite any direct economic opportunity for feeding cull cows, there is about 15-20 per cent of the cows in the main herd that for one reason or another should be removed and replaced every year. With a trend toward larger cow herds, the absolute number of culled beef cows is a growing reality on most cow-calf operations. Producers who have clear-cut reasons for culling cows and have a marketing plan can improve their prospects for profitability.
PeterVittiisanindependentlivestock nutritionistandconsultantbasedinWinnipeg. Toreachhimcall204-254-7497orbyemailat [email protected]