With the recent development of improved hazelnut germplasm for growers in the Upper Midwest, the industry is poised for rapid expansion. To facilitate this expansion the University of Wisconsin launched the Hazelnut Processing Accelerator in partnership with Northland College, the American Hazelnut Company, the Main Street Project, and the Bayfield Regional Food Producers Cooperative. The purpose of the Accelerator is to develop processing technology and equipment optimized to hazelnuts grown in the Upper Midwest while providing a bridge processing facility until production volumes are sufficient to support a financially viable facility. With more than two years of processing experience, we have identified waste streams that are not suitable for human food or require further processing that is too expensive at this time. Such waste streams may be suitable for livestock feed.
This project will evaluate the feed quality of undersized nuts, half-cracked nuts, and mixtures of the kernel and shell fragments and conduct a feeding trial with pigs to quantify the effect of the feeds on carcass and meat quality. Such information will allow pork producers and hazelnut growers in the Upper Midwest to capitalize on the growing market for mast-finished regional pork.
- Analyze the nutritional components of hazelnut screenings including: ground whole undersized nuts, half-cracked nuts, three mixtures of shell and kernel fragments.
- Evaluate the growth performance and meat quality of pigs finished with hazelnuts.
- Develop and publish a feeding program for hazelnut growers and pork producers for finishing pigs with hazelnuts.
- Conduct a consumer-preference and tasting survey for hazelnut-finished pork.
The first step of the project was to aggregate in-shell hazelnuts from Midwestern producers. To do so, we partnered with the American Hazelnut Company in Ashland, WI. Their cracking and cleaning line does not easily handle hazelnuts with 10mm and small hazelnuts. So, for this project we sorted out all the 10mm in-shell nuts from their line and then supplemented those with in-shell nuts (of all sizes) we purchased from other growers. Because of the challenge of cracking and cleaning such small hazelnuts we wanted to evaluate the feed quality and growth responses to whole in-shell hazelnuts when ground up.
The feed component data compared to soybeans are show on slides 4 and 5 of the presentation: Lammers – 2020 – Hazelnut Finished Pork. As the data show, hazelnut kernels have much higher fat, protein, and oleic acid content than soybeans, but when the shells are included the feed value drops significantly. The purpose, then, of our feeding trials was to evaluate the growth and carcass quality of pigs fed whole ground hazelnuts compared to a standard corn/soy diet.
Thirty-six, 135lb barrows were randomly assigned to one of six pens. Each pen received either the standard corn/soy ration or the corn-soy ration plus 10% whole ground hazelnuts, providing three replications of each treatment. The pigs were weighed every four weeks over a grow-out period of 69 days. At 69 days the pigs were ultrasounded and harvested. The trial was conducted twice with a summer trial during 2019 and a winter trial at the end of 2019. Only data from the summer trials has been analyzed so far.
In general, there was no change in the growth and performance, suggesting that whole ground hazelnuts can be fed at a 10% inclusion.
Two pork chops were harvested from each pig and analyzed for a range of meat quality attributes. There was no difference among the treatments in meat quality parameters or taste as evaluated by a sensory panel of tasters. Again, data from the winter trial are still be analyzed.
Although there was no change in meat quality, there was a difference in the fatty-acids of the fat in the animals. Pigs fed hazelnuts had lower palmitic acid, but higher oleic acid. Full results for the trials are not expected until summer 2020 when the covid-19 restrictions (hopefully) loosen.
Educational & Outreach Activities
The project involves two feeding trials: one held during the summer of 2019 and the other held over the early-winter of 2019 and 2020. The first trial and analysis of the trial was completed in time for the 2020 Upper Midwest Hazelnut Growers Conference (March 6-7) and the Midwest Organic Pork Conference March 13 and 14. Pete Lammers presented the results from the first trial at both conferences.
Per the conference evaluation at the Upper Midwest hazelnut growers conference, farmers reported an increased knowledge of the effect of adding ground-up in-shell hazelnuts to a hog ration.
The first trial indicated that although a 10% inclusion of ground-up in-shell hazelnuts did change the fatty-acid profile of the meat, the difference did not translate into a sensory panel difference in the meat. Although the feeding aspect of the second trial was completed, Covid-19 closed the UW-Platteville campus so the remaining work of the trial is on hold. As such we won’t have a complete picture until later this summer.
the hazelnut inclusion did change the fat in the hogs such that it had higher oleic acid. This means the fat is less solid at room temperature. This can create problems when processing and cooking the meat. At the 10% level, the change was not detrimental, but it would be good to conduct further trials to determine the upper limit. It would also be interesting to evaluate a poultry ration with hazelnuts to determine how it affects the eggs and meat. Feeding a mix of shell and split hazelnuts (a waste product from processing) to chickens would be easier because they can more effectively pick through it for the kernel. With pigs we have to grind it all up and they are therefore fed a fair amount of indigestible shell.