Higher energy and amino acid values of nutritionally enhanced corn hybrids are gaining pork producers' attention.

One variety backed by research from four land-grant universities is NutriDense, a hybrid created by ExSeed Genetics specifically for the end user — livestock.

Developed in the late 1990s by scientist Jerry Weigel, manager of nutrition and technical services for BASF (the North Carolina company that owns ExSeed), NutriDense has consistently shown a 5-6% higher energy value than yellow dent corn. It is not a genetically modified variety.

“Early work at the University of Illinois showed that an inbred crossed with an inbred would have nutritional properties for biological availability,” Weigel says. Once they determined its potential, the company had the hybrid field-tested by Kansas State University researchers.

Swine nutritionist Mike Tokach and co-workers from Kansas State University (KSU) conducted trials at a commercial research farm in southwestern Minnesota to determine if higher energy in NutriDense translated into true feed-per-gain benefit and growth.

It did. KSU research showed Nutri-Dense-fed pigs had a 2% higher average daily gain (ADG) and consumed 5.3% less feed, resulting in a 7% improvement in feed efficiency (FE), compared to pigs fed conventional corn. No fat was added to either ration.

NutriDense-fed pigs also had a 3.5% reduction in feed cost/lb. of gain when compared to pigs fed conventional corn plus 3% added fat. FE and ADG were similar.

“We then examined whether we could add higher levels of synthetic lysine, threonine and methionine because of the higher levels of other amino acids (isoleucine, tryptophan) in the corn,” explains Tokach.

“NutriDense has higher levels of all essential amino acids, but the advantage in higher levels of the fourth and fifth limiting amino acids for pigs is that it allows us to use higher levels of the amino acids that are economical to add as synthetics before another amino acid becomes limiting,” he adds. “Our research proved we can add more synthetic amino acids with NutriDense corn before performance is reduced.”

NutriDense contains about 23% more lysine, 19% more sulfur amino acids, 18% more threonine and almost 34% more tryptophan than yellow dent corn (See Table 1). The hybrid also has 25% more total phosphorus and 50% to 100% more available phosphorus than commodity corn.

Low Phytate Variety

Two KSU studies evaluated the effect of NutriDense low phytate corn in conjunction with increasing levels of added fat on growing and finishing pig performance.

The low phytate corn is similar to regular NutriDense, but with higher available phosphorus content due to lower phytate phosphorus. Experiments were conducted at the research facility in southwest Minnesota.

About 2,300 gilts were fed corn-soybean meal-based diets with yellow dent (YD) or NutriDense low phytate corn with either 0, 3 or 6% added fat.

Results showed that increasing levels of added fat improved growth performance regardless of corn source.

Not yet on the market, the NutriDense low phytate variety allows diets to have 37% to 63% less phosphorus than yellow dent corn diets, giving it a distinct environmental advantage.

The analyzed NutriDense low phytate corn was lower in methionine, cystine, threonine, tryptophan and phosphorus than the calculated values (Table 2). However, because the higher amino acid and available phosphorus levels in NutriDense low phytate corn were accounted for in diet formulation, the similar growth performance between pigs indicates that the formulation values for these nutrients in NutriDense low phytate corn appear to be appropriate, according to the KSU researchers.

More Amino Acid Research

Purdue University and South Dakota State University (SDSU) research reinforced protein and amino acid digestibility of NutriDense and yellow dent corn. A research summary provided by ExSeed showed:

  • SDSU work by nutritionist Hans Stein demonstrated significant improvements in lysine, methionine, cystine, threonine and valine digestibility. Overall, they showed a 4.5% improvement in crude protein digestibility.

  • Purdue University researchers Scott Radcliffe, Brian Richert and Alan Sutton showed significantly greater crude protein (8.9%) and tryptophan (3.8%) digestibility. Numerical improvements in individual essential amino acid digestibility ranged from 2.5 to 7% differences.

Hybrid Availability

BASF Plant Science LLC utilizes a select group of seed partners to deliver NutriDense hybrids to key markets.

Companies with license agreements to market hybrids with the NutriDense trait are listed on the Web site (www.nutridense.com).

Growers receive premiums. Delivery points are located throughout the cornbelt and more locations are being added. The hybrid has been grown in Iowa, Illinois, Nebraska and Indiana.

Yield performance is competitive with conventional yellow dent hybrids, according to the company. Data is available comparing performance of NutriDense hybrids to top-yielding hybrids over a several-year period.

Economic Breakdown

Kansas State researchers calculated the economic value of NutriDense corn compared to yellow dent corn in the '03 study. Diets were formulated to contain identical energy, lysine and phosphorus.

Values of $2.24/bu. for regular corn, $180/ton for soybean meal, $290/ton for monocalcium phosphorus, $40/ton for limestone and $240/ton for choice white grease were used in the calculations.

Using the difference in diet cost and amount of corn in the diets, they calculated the extra value provided by NutriDense at $0.13/bu. That means producers could pay a premium of that amount for NutriDense corn to realize the same growth performance benefits of a typical diet with added fat.

Table 1. Nutrient Composition of Corn Sourcesa
Item Yellow Dent Cornb NutriDense Cornc
Lysine, % 0.26 0.32
Isoleucine, % 0.28 0.41
Leucine, % 0.99 1.35
Methionine, % 0.17 0.21
Methionine & cystine, % 0.36 0.43
Threonine, % 0.29 0.34
Tryptophan, % 0.06 0.08
Valine, % 0.39 0.55
Metabolizable energy, kcal/kg. 1,551 1,630
Crude protein, % 8.50 10.00
Calcium, % 0.03 0.03
Phosphorus (P), % 0.28 0.32
Available P, % 0.04 0.13
aAs-fed basis. bValues are from National Research Council (1998). cValues were provided by ExSeed Genetics.
Table 2. Nutrient Composition of Corn Sourcesa
NutriDense Low Phytate Cornc
Item YD Cornb Calculated Analyzed
Lysine, % 0.26 0.32 0.32
Isoleucine, % 0.28 0.41 0.36
Leucine, % 0.99 1.35 1.25
Methionine, % 0.17 0.21 0.18
Methionine & cystine, % 0.36 0.43 0.38
Threonine, % 0.29 0.34 0.31
Tryptophan, % 0.06 0.08 0.06
Valine, % 0.39 0.55 0.49
Metabolizable energy, kcal/kg. 3,420 3,591 3,591
Crude protein, % 8.5 10.00 9.65
Calcium, % 0.03 0.03 0.03
Phosphorus, % 0.28 0.32 0.30
Available P, % 0.04 0.16d 0.15d
aAs-fed basis. bYellow dent corn values are from the National Research Council (1998). cCalculated and analyzed values of NutriDense Low Phytate corn courtesy of BASF. The calculated values were used in diet formulation.
dAvailability of the phosphorus in NutriDense Low Phytate corn was assumed to be 50%.

Figure 1. Biotech Share of U.S. Corn Per Thousand Acres Planted, 2005

According to the National Corn Grower's Association 2006 World of Corn publication, biotech corn hybrids grown in the United States accounted for 26% of planted corn acres in 2005, up from 25% two years earlier.

Corn with stacked traits, such as NutriDense, accounted for 9% of planted acres in '05, up from 4% two years prior.

Biotech hybrids have had a significant effect on the use of pesticides. American corn producers used 23.3 million pounds fewer pesticide active ingredients on U.S. cornfields as a result of biotech hybrids in 2004.

World of Corn also notes that more than 90 ethanol production facilities are in operation across the United States, with at least 20 more expected in production by the end of this year.

Increased efficiencies in both ethanol and corn production have boosted the net energy balance of ethanol production to 1.67 to 1. In other words, ethanol production results in 67% more energy than it takes to grow the corn.

Non-Biotech 39,244
Biotech 21,257
Herbicide-Tolerant 13,899
Stacked Traits 7,358
Total 81,758

Source: USDA, NASS, Acreage Report June 30, 2005