Cattlemen learn their ABCs and EPDs for profit

By MINDY POEHL | Central Texas Edition

Dr. Mark McFarland details nitrogen fertilization in forage production at the recent Beef Cattle Short Course. -- Staff photo

August 11, 2005 - Every cattle producer wants his cow herd to be the best. At the 51st Beef Cattle Short Course at Texas A&M University, Aug. 1-3, beef cattle producers were there to learn about making a profit off of their cattle.

Dr. Jason Cleere, Extension beef cattle specialist and conference education coordinator, discussed Expected Progeny Difference (EPD) and how the cow-calf producers can use them.

EPD is the estimate of how the future progeny of each sire are expected to perform in each specific trait.

"EPDs have proven to be the most effective tools for genetic improvement of beef cattle. Since the majority of the genetic progress within a herd is a direct result of sire selection, EPDs should be given careful attention when choosing bulls," explained Cleere. "With the vast number of EPDs that are available for use, selection goals must be carefully established to determine which EPDs are of primary importance."

EPDs should be combined with other selection criteria, such as structural and reproductive soundness, to determine which sires are most suitable, said Cleere.

Once selection criteria has been established, it should answer questions such as "what traits do I need to improve?" For example, if a producer has a goal of increasing the weaning weight of the calf crop, the weaning weight EPD would be defined as a primary EPD selection criteria for a new bull.

"When it comes to EPDs, saying that more is better is not relevant," Cleere said. "Higher weaning weight EPDs would definitely achieve the goal of enhancing weaning weights, but there also might be related reductions in calving ease due to higher birth weights. Having a balanced trait selection is always important."

Defining the best EPD criteria is challenging. Cleere said knowing the EPD value of former and current sires in the herd can provide insight and assistance when it becomes difficult. Associating EPD values on current and former sires with the performance of their progeny is useful to establish a guideline from which to select future sires.

"The basic theory is that defining where we are headed is much easier if we can characterize where we have been," summarized Cleere.

For many producers, forage management is an important key for getting the best out of their herds. In this regard, Dr. Mark McFarland, soil fertility specialist, spoke about nitrogen fertilization.

"Research has shown a linear relationship to added nitrogen in soil in terms of yield and quality of bermudagrass," McFarland said. "Plant recovery of applied nitrogen fertilizer generally decreases with increasing rates in current production systems."

McFarland suggested uniformly applying most of the nitrogen to fields early in the spring based on a yield goal. When the land is dry, it is better to set the yield goal above that of average yields.

"Yield goal clearly indicates the risk the farmer is taking when he calculates the amount of fertilizer for the crop before production. For every 1 ton yield goal of bermudagrass production, an average of 50 pounds of actual nitrogen fertilizer is required," explained McFarland.

Organic fertilizers are an important option.

"Of all the components of soil, organic matter is probably the most important and most misunderstood," he said.

Organic matter serves as a supply of nutrients and water in the soil, aids in reducing compaction and surface crusting, and increases water infiltration into the soil.

"Although organic matter positively helps soil, it is often ignored," McFarland said. "Organic material becomes organic matter when is decomposes into humus. Humus is organic material that has been converted by microorganisms to a resistant state of decomposition."

Organic matter, unlike organic material, is stable in the soil. And, only about 5 percent of it mineralizes yearly. Each percent of organic matter in the soil releases 20 to 30 pounds of nitrogen and 2 to 3 pounds of sulfur per year. The nutrient release mainly occurs in the spring and summer, so summer crops benefit more from organic matter mineralization than winter crops, said McFarland.

"Tillage improves the aeration of the soil and causes a flush action that speeds up the decomposition of organic matter. Tillage also often increases erosion. No-till practices can help build organic matter on land," McFarland said.

McFarland pointed to the importance of fertilization.

"Always take a soil sample," he said. "Then you will know if your land has enough nutrients or not."

Proper fertilization encourages the growth of plants, which increases root growth. Increased root growth can help build or maintain organic matter, which is beneficial in crop or forage production.