University of Illinois researchers have determined the nutritional content in three relatively new feed supplements that can be added to weanling hog diets in place of soybean meal, adding to the number of options hog producers have to feed their young pigs.
Soybean meal must be substituted in nursery pig diets because some of its proteins are not digestible for the young hogs. In the past, the most common substitutes were fish meal and plasma, but Hans Stein and his team of researchers have now identified more information about three other substitutes: dried fermentation biomass, PEP50 and PEP2+.
Stein's team measured the amino acid content and digestibility, digestible and metabolizable energy concentration, and phosphorus content and digestibility of the each of the three supplements.
According to Stein, DFB contained 77% crude protein, and the PEP50 and PEP2+ 53 and 59%, respectively.
"All of these ingredients are relatively high in crude protein," Stein said. "And there's a lot of lysine in the dried fermentation biomass because extracting lysine from the biomass is not a 100% efficient process."
Stein explained that DFB consists of the material left over when lysine has been extracted from fermentation tanks containing lysine-producing bacteria.
PEP50 and PEP2+, in contrast, are byproducts of the production of heparin.
The digestibility of amino acids in DFB and PEP50 was generally at least as high as in fish meal and sometimes greater than in fish meal, while the digestibility of most amino acids in PEP2+ was about the same as fish meal or slightly less, the research found.
However, the lower protein content in PEP50 and PEP2+ means that the concentration of digestible amino acids in these ingredients was less than in fish meal, Stein said.
"Producers now know what the digestibility of nutrients and energy in these products are so they can formulate diets based on digestible concentrations of nutrients," he said. "These are very digestible products, and very good sources of amino acids."
Results from the study also showed that the concentration of metabolizable energy in DFB, PEP2+ and PEP50 was 5,236 kcal/kg, 4,617 kcal/kg and 4,512 kcal/kg, respectively.
The standardized total tract digestibility of phosphorus was greatest in DFB (96.9%) and PEP2+ (97.6%), followed by PEP50 (76.2%).
Stein said that fish meal contains approximately three times as much phosphorus as DFB, PEP50, and PEP2+, so the concentration of digestible phosphorus in these ingredients is still less than in fish meal.
"Producers who substitute these ingredients for fish meal would need to supplement the diets with additional phosphorus," Stein advised.
With the nutritional values addressed, Stein expects his team will move on to performance testing each of the supplements.
"We need to do some performance experiments to confirm that we can use 5, 6, or 7% of each of these ingredients in the diets, and take out fish meal and maybe even some plasma as well," he said.