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How many bulls do you need?

The Dickinson Research Extension Center recently decreased the center’s bull population. The average bull age at the center at turnout has been 3 years. Seldom would a bull more than 5 years of age be turned out to breed.

As a result, the 10 remaining bulls are two Lowline and eight Red Angus bulls. They will average 3 years of age at turnout next spring. Every time the bull pen is evaluated, concerns about refilling are considered.

The cash outlay is real. Regardless of weight and price, the cull-bull check of $903.50 per head is never as large as the bull-buying check needs to be. As a matter of course, the center runs cows in many different pastures and errs on the side of having more bull power, not less, when it comes to running bulls.

At the research center, some cows are located in very small pastures and others in larger pastures, but every pasture needs a bull. The targeted ratio is one bull to 30 cows, but the actual number will vary depending on pasture size. Bull-to-cow ratios are variable throughout the industry. Some producers are adamant that bulls can cover twice the number of cows the center stocks, while others feel more bulls are better.

Two failures

The center’s bull stocking rate has failed only twice in recent times. Several years ago, a set of heifers came off pasture with none of the heifers bred. One bull was utilized, so there was only one bull to blame. Never assume bulls are working.

In contrast, the center has a pasture 50-plus miles away. This year, four bulls were turned out with the 44 cows on that pasture. However, only 33 cows bred, so more bulls are not always better. In fact, in this case, they were worse.

All of the center’s bulls are fertility checked in the spring, so the four fertile bulls perhaps spent more time deciding their pecking order and less time breeding cows. These were bulls that were 2 years old, and whether or not dominance played a factor is only speculation. All four bulls went to market.

Excess bulls are just that — excess. They do not add much to an operation except more bills.

Target markets

The research center’s mature cow herd is targeted at 200. On paper, that would beenough bulls, but as noted earlier, smaller pastures require more bulls.

The center is also trying to produce two different types of calves. Eighty cows are targeted to produce heavy-muscled calves with reduced frame and a slightly slower growth rate. These calves will end up on a grass program and are projected for an older-yearling market.

The rest of the cows — about 120 head — will produce traditional fast-gaining, high-lean calves for the calf-fed market. These calves will meet the market for calves less than 20 months of age.

The current bull inventory will sire calves that meet a grass-fed market. The average expected progeny differences values for the eight Red Angus bulls are birth weight, minus 2.3; weaning weight, 26.4; yearling weight, 56.6; milk, 23.5; marbling, 0.28; rib-eye area, 0.23; and back fat, 0.02.

This means the bull pen is in the upper 25% of the Red Angus breed for birth weight, milk, marbling and rib-eye area.

On the growth side, these bulls are in the lower 50 percentile for weaning weight, yearling weight and back fat. Keep in mind these calves are going to grass and will be targeted to market at less than 24 months of age.

Obviously, the research center will need to buy different bulls for the 120 cows designed for the high- growth calf-fed market. Expectations are that these calves will be on the rail at 15 to 18 months of age. In this case, the growth numbers need to be upped for the second cow herd.

Ringwall is a North Dakota State University Extension beef specialist.

This article published in the February, 2011 edition of DAKOTA FARMER.

All rights reserved. Copyright Farm Progress Cos. 2011.