The Most Valuable Investment in the Beef Herd - the Bull
Beef producers are often called upon to buy feed, minerals, equipment, and other items that are promised as the “best investment for your farm.” There is only one real investment in the farm that can always live up to the promise-the bull in the pasture. If you have a closed herd, the genes in that cow herd will come solely from the bulls you select after just a few generations (Table 1.)
Table 1. Impact of Bull Selection in a Closed Herd of Beef Cows
|Year||% of genes from selected bulls
20% replacement rate in the cow herd
For the beef cow-calf enterprise the sale of a live calf is the only source of income-unless you count the sale of cull cows that did not get bred or lost a calf. The first step in that process is having a bull available that will accomplish two things-get the cow bred when she is in heat, and provide the most pounds possible across the scales at sale time for the calf.
Getting the Cow Bred
If we track the cycle of events that leads to a live calf across the scales, we have to have a fertile bull with a fertile cow at the right time. Cow fertility is another story for another time. Fertility in young bulls is a function of age, genetics, nutrition, and other factors. The only objective method of measuring fertility is with a breeding soundness exam (BSE). This process combines most of the factors involved in fertility (scrotal size, sperm concentration, sperm morphology, and a physical exam of the reproductive organs) to arrive at a score that will value potential fertility. Failure to meet specific benchmarks for any of the factors results in a BSE failure. This score has been proven in the field to be very efficient in measuring bull fertility. Most central bull tests stations provide a BSE exam on bulls sold through the program. There are few veterinarians available, however, that provide an on-farm BSE.
A second factor of fertility in bulls is making sure the fertile mating can occur. Yearling bulls that are turned in with more than 15-20 cows will result in a costly breeding season. A yearling should not be expected to breed more than one cow per day. If we consider there will be at least one cow in heat every day in a 20-cow herd (a 21-day reproductive cycle), this is the maximum breeding herd for the young bull. It can be increased to 30 cows for the 2-yr old, but should never exceed 40 cows for any bull. Why? If a cow has a fertile heat, but is not bred until the next heat cycle, it will cost the producer about $40 per calf from lost weaning weight.
A third factor is buying the bull that has a greater chance of producing a live calf. Birth weight of calves is the single most important factor in calving difficulty, and difficult calvings result in dead calves, dead cows and (or ) cows that do not rebreed. Using genetic information such as EPDs for birth weight have proven there will be fewer difficult calvings and more live calves. All breed associations publish the average EPD for birth weight in their population of bulls, so select bulls that are below breed average for birth weight EPD for breeding young cows. Keep them below breed average if heifers are to be retained in the herd from any cows because half of the genes for birth weight come from the dam.
Getting More Pounds
The most expensive bull a producer can buy is the one from the sale barn with no genetic records. It is like buying a tractor to pull a 6-row corn planter without ever looking at it or knowing the horsepower. The technology for breeding cattle is such that there is no reason to buy inferior bulls. Expected progeny differences (EPDs), performance records, and genetic markers are all there to use to get the most from the bull-buying decision. Consider this example of using EPDs to select two bulls:
|Birth weight EPD||3.0||3.0|
|Weaning weight EPD||45.0||30.0|
These EPDs tell us that, when bred to an average group cows, Bull A will wean calves that are 15 pounds heavier than Bull B, and both will have the same average birth weight. If we use these bulls on an average of 30 cows over 4 years and wean 90% of the calves, we will expect Bull A to wean 1620 more pounds of calf. At $1.00 per pound, that is $1620 more value over the life of the bull. So, that is why the $1500 bull is about $1100 more expensive to own than the $2000 bull. We actually did this comparison on a farm a few years ago, and found the difference was more like 50 pounds per calf, and a bull that could be bought for $2000 was actually worth $5000 to that herd. Consider also bulls are “rented.” For the initial cost of $2000 for a bull that is sold for $600 when he is culled after just 4 years, the cost to breed each cow for 30 cows each year is just $11.66.
In the decision to buy bulls, set the goals for the herd, find bulls with the genetic information that can reach those goals, disregard those bulls without known genetic value, then select the bulls based on the breed, phenotype, or color you want. It will indeed be the most important investment you make.