A hot topic in swine nutrition is conjugated linoleic acid and its potential benefits. A second source of CLA is now getting some attention as a possible alternative to the early version.

Research at Kansas State University is focusing on the effects of modified tall oil, a byproduct of kraft paper manufacturing. Modified tall oil contains isomers of conjugated linoleic acid. And early trials indicate it may provide the same kinds of benefits as CLA processed from sunflowers.

CLA is a growth promotant that shows potential to help firm bellies. The isomer identified in sunflower-derived CLA exists in modified tall oil. But other isomers of CLA also are present in the oil, notes Patrick O'Quinn, the Kansas State graduate student conducting studies with the alternative product.

In an early head-to-head trial with CLA derived from sunflowers, tall oil produced better average daily gains and feed intake. More data is needed to see if either ingredient will offer significantly better growth rates, lean percentage, meat quality and other benefits.

In a separate trial, a 0.5 percent supplement of tall oil resulted in 1.8 percent higher lean percentage than a control diet. It also produced a 0.33-square-inch larger loineye. Drip loss was 3.6 percent compared to 5.2 percent.

But of most interest, especially to packers, was a reported 18 percent improvement in belly firmness.

O'Quinn admits that more research is needed to find which CLA isomers from which products produce the greatest package of desired results. But modified tall oil appears likely to be less expensive than CLA. It could offer up to a 3-to-1 return on investment if the results of these early trials hold up.

For now, keep your eyes open for more research as nutritionists look for ways to improve growth, backfat levels and muscle quality with modified tall oil- and sunflower-derived CLA.