By Garth Ruff
Bull buying season is almost upon us, and for the smaller cow-calf operators in the region, I think it time to ask the question: Do you need to buy a heifer bull? Year over year as I sit and watch bull buying decisions being made, I have observed producers faced with the dilemma of buying a calving ease “heifer bull” or a higher performance sire with a slightly higher birth weight. Part of the dilemma is the total the cost of the bull, where locally, a “heifer bull” will cost more, due to the willingness of cattlemen to pay for calving ease sires.
Before tackling this question it is important to recognize that the past quarter century, the beef industry has made tremendous strides in the area of genetic improvement, a large part of which can be attributed to the adoption and understanding of Expected Progeny Differences (EPD’s). With a desire for calving ease, one of the most studied and most utilized EPD’s by cattlemen when purchasing bulls is Birth Weight (BW) and more recently, Calving Ease Direct (CED). Another data point to consider is the Accuracy of a given EPD. Accuracy values range from 0 to 1. Often high accuracy bulls that have had hundreds, perhaps thousands of progeny data points are considered to be proven bulls.
According to the 2017 Census of Agriculture, the average cow herd size in Ohio is about 17 cows. For the sake of math, let’s assume on an operation of 20-25 cows and the following conditions. 1) the annual culling rate is 15-20 percent and 2) that there is on a single bull on the farm. This would mean culling 4-5 cows and keeping that many replacement heifers annually. Does 15-20 percent of the herd dictate how bull buying decisions are made? If selling cattle by the pound, how much production (revenue) is lost by breeding mature cows to calving ease bulls?
When it comes to making genetic decisions, one needs to consider the resources available when evaluating potential sires. Available labor is one resource to be considered. A live calf is always more valuable than a dead calf. If labor is a limiting factor, then there is a case to be made for a “heifer bull” in a single bull herd.
However, if labor is not a limiting factor, there are options available to capitalize on genetic improvement within in the herd. Consider the following scenarios in which the goal is to capitalize on both calving ease for replacement heifers while adding pounds and performance to calves from our mature cows.
Figure 1. Example EPD’s of calving ease sire (Bull 1) and high growth and performance sire (Bull 2).
Scenario #1: Artificially Inseminate Heifers
If genetic improvement is a goal, artificially inseminating heifers to a proven calving ease A.I. sire can be advantageous. When utilizing a calving ease bull with an accuracy of 0.8 or greater for CED and BW, the risk for calving difficulty is much lower than compared to using an unproven yearling or two-year-old bull to breed heifers. By combining estrous synchronization with A.I. there is the increased ability to calve heifers in a shorter calving window. First calf heifers traditionally have a longer post-partum interval before returning to estrous. Compared to mature cows, it’s recommended if possible, to calve first calf heifers early in the calving season to allow for an increased probability of rebreeding within the desired breeding season.
With regards to a bull purchasing decision, calving ease should be less of a concern if only using natural service sires on mature cows. Performance EPD’s such as Weaning Weight, Yearling Weight can be of greater consideration if selling feeder cattle. If maintaining ownership throughout the feed period, one can also focus and capitalize on terminal traits such as Back Fat, Ribeye Area, and Marbling or Percent Intramuscular Fat (%IMF).
Scenario #2: Sell Heifer Calves and Purchase Bred Replacements
Raising replacement females efficiently and correctly requires a level of management that is often not feasible within small herds. To meet nutrient requirements, in a ideal system, one would raise replacement heifers and two-year-old females separate from the mature cow herd. Those younger females still have nutrient requirements for growth and development, whereas the requirements of mature cows are often met maintenance levels. If unable to manage the development of replacement females correctly there is a cost associated. That cost could be calving difficulty, longer post-partum intervals, reduced conception rates as two year olds, or reduced milk production.
Once again, this scenario also allows for the utilization of genetics that will add productivity to the mature cows in the herd.
When making the decision to raise or purchase bred replacement females there are some additional factors to consider. Lee Schulz and Patrick Gunn at Iowa State University suggest there are potential advantages to both decisions (see Table 1).
Table 1. Potential advantages to either raising or purchasing replacement beef females.
| Raising Replacement Females | Purchasing Bred Replacements |
| Genetic Control | Free-up Resources for Alternative Uses |
| Understanding of a Replacement Heifer’s Background | Reduced Bull Power and Allowing Increased Emphasis on Non-calving related EPDs |
| Control over Disease | Expand Herd or Change Breeding Program in Less Time |
| Cost Less to Raise than Buy | May Be Able to Buy Genetically Superior Heifers |
| | Cost Less to Buy Than Raise |
Summary
Selecting a herd bull is an important decision that will have long lasting impacts on the productivity and profitability of the cattle enterprise. By utilizing EPD’s and setting goals for continuous genetic improvement there are options are available to the small beef cattle producers in Ohio and across the Eastern Cornbelt. Economic and management consideration should be made when deciding which bull best suits your operation and management capabilities.
Source : osu.edu