J.H. Helm, P.E. Juskiw, L. Oatway and W.C. Sauer

Since it was first released in the late 1980's, hulless barley has become an economical quality alternative for feeding pigs. However, variability has been observed in the feeding quality. It has long been known that environment plays a large role in determining grain protein content; is there an equal effect upon the digestibility of the protein and energy in the pig? This study was undertaken to determine whether this variability in protein and energy digestibility in a pig, and total energy and protein content of the grain was due to the effects of the genetics (the variety) or the environment (climate, weather, and production practices).

In this study, the genetic or varietal factor was found to be the primary effect influencing end-use quality. This was mainly due to the presence of the hulled variety and, to a lesser extent, the waxy starch types that had lower feeding value. The effect of the year on quality was greater than the location effect despite the great differences in soil type, fertility, rainfall and yield between locations. The data did support the premise that those environments or years that promote yield also promote feed quality. For the producer, this means that if a good variety is chosen and good growing conditions are present which result in high yield, then the better the feed quality will be. It also indicates that as we develop new higher yielding varieties that can adapt to environmental stresses we can expect to see the feed quality of the grain increase as well.

The greatest expense and difficulty in selecting for nutritional quality is the cost and time it takes to obtain results from animal testing. It would be of benefit to the feed industry as well as the scientific community to develop a quick, easy method to determine feed value. The Near Infrared Reflection Spectroscopy (NIRS)technology is quick and easy. The fact that this study used a large number of samples from a three-year span and from several locations gave us an ideal situation to develop calibrations for NIRS. The NIRS can be used in the future to replace the pig indigestibility studies. The results were very good, giving very high correlations between the NIRS, the pig and the laboratory. These results indicate that in the near future, the grain producer and the hog producer will be able to rapidly determine the value of the grain on a quality basis. This will eliminate the need to overbalance rations which promotes waste and higher costs of production. These results have given the plant breeder a new tool for screening for genetic differences in protein and energy digestibility.