December 19, 2013
US researchers share oilseed nutritional value in pig diets
Researchers at the University of Illinois are now studying the nutritional value of Camelina sativa, increasingly valued as an oilseed crop, when used as part of weanling pigs'' diets.
When oil is extracted from the camelina seeds, using either solvent extraction or expeller pressing, the oil is then used in fuel production. The defatted meal that is produced during this process is high in protein and may be fed to livestock, but there is very little knowledge about the nutritional value of camelina meal when fed to pigs, said Hans Stein, a professor of animal sciences.
"Camelina seeds and expellers have been evaluated for use in poultry and dairy cattle diets, but to our knowledge, the nutritional values of these ingredients have not been studied in pigs," he said.
Stein and his team fed growing pigs diets containing one of five different camelina products to determine amino acid digestibility values. They tested camelina seeds from two different sources as well as camelina expellers from three different sources. The camelina products were compared with each other and with rapeseed meal.
The digestibility of crude protein and most amino acids in two sources of camelina expellers did not differ from that of rapeseed meal whereas the third source had lower digestibility values. Digestibility values in both sources of camelina seeds were less than in rapeseed meal.
Stein said that the variation in digestibility among the sources of camelina expellers might be due to genetic differences between the seeds or differences in the oil extraction procedures.
"However, amino acid digestibility in two of the sources of camelina expellers was comparable to that of rapeseed meal, which indicates that camelina expellers may be included in diets fed to pigs," he explained.
The camelina expellers studied were cold pressed and contained greater levels of trypsin inhibitors than rapeseed meal. Amino acid digestibility in camelina products might be improved by heat treatment, provided that heat damage is avoided.
These findings will help producers and feed companies evaluate camelina expellers for possible inclusion in pig diets. Stein said that the next steps for research would be to determine the digestible and metabolisable energy content of camelina expellers and to conduct growth performance studies.