About 16¢ worth of pantothenic acid (vitamin B5) may have a significant effect on a pig's lean percentage, according to Iowa State University (ISU) research.

Work headed by ISU animal scientist Tim Stahly shows an increase in carcass lean up to 2% and a reduction in backfat by adding 45 ppm (parts per million) of supplemental pantothenic acid to grow-finish diets. Three studies in the last three years have all shown a statistical improvement.

The research was proof enough for Gregg Sample, a nutritionist for Next Generation Pork, Spring Valley, MN. Pigs 50 lb. and up have been receiving extra vitamin B5 for more than a year.

Next Generation Pork markets over 75,000 head a year to Hormel Foods, which pays according to weight and last-rib backfat. After four years of emphasis on backfat reduction, Next Generation market hogs average 0.88 in. Sample credits feeding pantothenic acid, a change in terminal sires, higher lysine levels in late finishing and more accurate feeding due to a new feedmill for the backfat average.

“There needs to be more data on the issue, but it's cheap to add (compared to the return a small improvement in backfat can produce), so we'll continue to feed it until someone proves otherwise,” Sample says.

Hormel's feed division, which provides Next Generation's premix, has also run pantothenic acid trials. Almost 1,000 barrows and over 1,000 gilts were used in a commercial study, explains Larry Dunn, Hormel production manager. “The statistical work showed (the effect on) 10th-rib backfat was significant with 0.1% improvement in barrows and 0.05% in gilts. Percent lean went from 55.7% to 56% on barrows, and from 56.6% to 57% on gilts.”

The premix contains 55-65 ppm of pantothenic acid in the form of d-calcium pantothenate, says Dunn, noting a per-pig cost of 16-18¢. Other vitamin-trace mineral levels did not change in the diet formulation, but they did make sure levels were at or above those used in the ISU studies.

Stahly points out that their studies were not designed to determine optimal level of the vitamin nor the length of time it should be fed. However, minimum amounts appear to be 45 ppm for carcass improvement, he says.

The most recent ISU trial used group-housed, lean, commercial pigs. Carcasses were measured with leased instrumentation used in packing plants — CVT-2 ultrasound, a Fat-O-Meater and a last-rib backfat ruler.

“The pantothenic acid did not change weight gain nor feed efficiency, but again showed significant increases in muscle and decreases in backfat, which were picked up by each of the three instruments. In our estimates of value, our scenarios came up with a $2 to $15 return per dollar investment in the technology of pantothenic acid,” he adds.

“One of the nice things about pantothenic acid is that toxicity studies show no upper limit. It is considered safe at any level,” Stahly says. “We also made sure all other vitamins were substantially higher than published requirements to ensure opportunity for response. Some people struggle with that; they want to have other vitamins at published requirements and only change this one. To me, that flies in the face of what we understand about amino acid nutrition.”

Vitamin levels in Stahly's work were added at six times National Research Council published amounts. Most of those requirements were determined in the '60s and '70s. “But in today's pigs, we're not sure six times is even high enough,” he says.

No Response in Kansas Trials

Kansas State University followed up Iowa's results with their own trials. Nutritionist Bob Goodband reports that they haven't seen the same response at the 45 ppm level. “We are still analyzing some data, but we haven't seen any growth or carcass benefits to date.”

Three projects have been completed — two growth performance trials fed pantothenic acid from 50 to 260 lb. with no response. A third study was a metabolism study feeding different levels of the vitamin to pigs. Individual recordings were taken to look at digestible energy and whether changes in nitrogen retention were associated with a change in acid levels. Results of that study are under analysis.

Only pantothenic acid levels were elevated in the Kansas studies. “I wouldn't expect other vitamin increases to be necessary,” Goodband says, “but there is certainly interest in re-evaluating vitamin requirements for today's high-lean pigs.”