By Diane DeWitte, UMN Extension swine educator
Originally printed in The LAND - as July 5, 2024, Swine & U column
Recently, on a rain-threatened day in late May, organic farmers, University researchers and personnel from the UMN West Central Research and Outreach Center (WCROC) gathered to hear the latest results of an ongoing Organic Swine & Hybrid Rye project. The field day began after a pulled-pork lunch with an hour of presentations reviewing the research and its findings thus far. Folks in attendance had the chance to ask questions of the presenters; however, in a “first” for the researchers, the gathering appeared as a Facebook Live event from the WCROC Facebook page.
The project’s lead investigator Yuzhi Li provided an introduction of the previous organic projects which brought us to this day and explained that the UMNCROC hosts the only certified organic swine facility on a Land Grant University in the U.S.
Dr. Li collaborated with a multidisciplinary team to complete this project, including Lee Johnston, UMN swine nutrition professor, William Lazarus, UMN Extension economist, Melissa Wilson, UMN Extension Nutrient Management Specialist, Axel Garcia y Garcia, UMN Agronomy professor, Ryan Cox, UMN meat science professor, and Joel Tallaksen, UMN WCROC renewable energy scientist. In addition, two UMN animal science graduate students, Megan Kavanagh and Gabriella Lima worked tirelessly on the swine aspects of this project throughout the two seasons of pig growth and harvest. Countless UMN WCROC farm personnel assisted with the logistics of growing and harvesting rye and pigs.
However, hybrid rye can grow well in light to heavy soils, has a tolerance to poor soils and drought, and has excellent tolerance to very low temperatures. Of course, hybrid rye performs best when appropriately fertilized according to soil tests and thrives within an effective weed & pest control program. His final remarks pointed out that hybrid rye has more advantages than disadvantages; it fits our region, and it fits organic production.
In the study, the control pigs were fed a classic organic corn-soy diet. The rye treatment pigs were fed an organic diet which replaced 50% of the corn with hybrid rye. The control and rye pigs were raised side-by-side across the fence in the WCROC’s swine hoop barn. There were 50 pigs in each treatment (100 in the group) and we are currently finishing the fifth group. In all, 500 organic pigs, born and raised at WCROC, have gone through the feeding trials.
Gabriella reported that she and Megan Kavanagh recorded and calculated the pigs’ individual weights, feed intake, average daily gain (ADG), average daily feed intake (ADFI) and feed/gain (F/G). The pigs spent 10-13 weeks on the feed trial, and were harvested once they reached 270 lbs.
In this study, Gabriella and Megan used a new identification and weighing technology called LeeO. Pigs were tagged with an ultra-high-frequency ear tag. Using an electronic reader on a long arm, a Bluetooth enabled electronic scale head, and a tablet computer, the students scanned the pig’s ear tag as it entered the scale; the scale connected with the tablet and recorded the pig’s weight on the tablet. This technology offers ease, accuracy and record-keeping simplicity to pig farmers who adopt it.
The takeaway from this portion of the study is that hybrid rye can replace 50% of corn in swine diets without compromising overall performance.
The 2022 rye crop at WCROC yielded 104 bu/acre grain and 1.8 ton/acre straw. In 2023, the yields were affected by droughty conditions with a grain yield of 69 bu/acre and 1.0 ton/acre of straw.
Megan shared the production costs per acre of growing organic hybrid rye:
Seed: $60
Fertilizer: $96
Machinery + Labor: $222
Rent: $132
Miscellaneous: $80
Total cost: $590/ac Straw Costs
Baling + Storage: $50/ac
$150/ton paid by WCROC 2022 + 2023
The following table provides cost comparisons and potential savings in organic pig production using hybrid rye as a substitute for part of the corn in the pigs’ diets. Drought effects on the 2024 season’s production reduced the potential savings considerably.
Three objective measures were taken. Carcass pH was collected at 45 minutes and 24 hours post-mortem. Lower pH contributes to a brighter, redder meat color. Pork color was measured and the Warner-Bratzler shear force test was performed. Shear force is the force required to cut through a sample and is considered an indicator of meat tenderness.
Two subjective measures were taken: Color and marbling scores.
There were no significant differences in pH at 45 minutes or 24 hours between control & rye pigs. Shear force measurements were not significantly different, either. There was a higher objective color measurement in the control pigs, indicating a lighter colored meat.
Subjectively, there were no significant differences in the color or marbling scores between control & rye pigs.
The UMN Food Science and Nutrition Sensory Center at St. Paul provided 73 taste test panelists 18 years and older. The Likeness ratings were a 120-point scale which evaluated the overall liking, liking of flavor, and liking of texture. The Intensity ratings were a 20-point scale which rated juiciness, toughness and off-flavor. Panelists were provided a sample of cooked pork loin, unidentified between control and rye pigs.
The Likeness ratings of overall liking, flavor and texture were comparable between rye and control pigs. In the Intensity ratings, panelists judged the rye pork to be tougher compared to the control pork. To summarize, replacing 50% of corn with hybrid rye did not negatively impact pork quality and consumer eating experience.
Additional support for the project was provided by Forever Green Initiative (FGI) at the U of MN and the Midwest Transition to Organic Partnership Program (TOPP). TOPP is just beginning and is an outreach to connect transitioning organic producers with mentors. More information can be found at organictransition.org.
Matt Leavitt from FGI shared with attendees at the field day current opportunities available to transitioning organic farmers. Additionally, Matt created a Forever Green Initiative technical bulletin about hybrid Rye using data from this project. https://z.umn.edu/FGIryeTechBulletin
What’s next? A team representing the UMN WCROC, UMN- Morris and the UMN-Twin Cities has received an OREI grant to develop an organic agriculture curriculum, and the project is currently underway!
Diane DeWitte is an Extension Educator based in Mankato. She can be reached at stouf002@umn.edu.
Originally printed in The LAND - as July 5, 2024, Swine & U column
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| Photo Source: Diane DeWitte, Organic Swine & Rye project |
The project’s lead investigator Yuzhi Li provided an introduction of the previous organic projects which brought us to this day and explained that the UMNCROC hosts the only certified organic swine facility on a Land Grant University in the U.S.
Dr. Li collaborated with a multidisciplinary team to complete this project, including Lee Johnston, UMN swine nutrition professor, William Lazarus, UMN Extension economist, Melissa Wilson, UMN Extension Nutrient Management Specialist, Axel Garcia y Garcia, UMN Agronomy professor, Ryan Cox, UMN meat science professor, and Joel Tallaksen, UMN WCROC renewable energy scientist. In addition, two UMN animal science graduate students, Megan Kavanagh and Gabriella Lima worked tirelessly on the swine aspects of this project throughout the two seasons of pig growth and harvest. Countless UMN WCROC farm personnel assisted with the logistics of growing and harvesting rye and pigs.
Organic hybrid rye
Dr.Garcia highlighted the value of adding rye to a farm’s cropping system, whether conventional or organic. Hybrid rye, in contrast to traditional varieties & other small grains, provides superior traits which result in higher yields, better disease resistance, and improved stress tolerance. Its robust performance makes it desirable for use in organic and other sustainable agriculture applications. He discussed hybrid rye’s disadvantages, primarily its higher seed cost compared to other small grains. In addition, some hybrids tend to be site-specific.However, hybrid rye can grow well in light to heavy soils, has a tolerance to poor soils and drought, and has excellent tolerance to very low temperatures. Of course, hybrid rye performs best when appropriately fertilized according to soil tests and thrives within an effective weed & pest control program. His final remarks pointed out that hybrid rye has more advantages than disadvantages; it fits our region, and it fits organic production.
Feeding hybrid rye to organic pigs
UMN Master’s student, Gabriella Lima, shared the basics of the organic rye feed trial. Hybrid rye has a high energy content which is 92% of the energy of corn. Rye in the diet increases phosphorus (P) digestibility; researchers have worked for years to reduce the amount of P excreted in livestock manure because of the potential for high P loads in soils. Soluble fiber in rye is an added benefit in a pig diet.In the study, the control pigs were fed a classic organic corn-soy diet. The rye treatment pigs were fed an organic diet which replaced 50% of the corn with hybrid rye. The control and rye pigs were raised side-by-side across the fence in the WCROC’s swine hoop barn. There were 50 pigs in each treatment (100 in the group) and we are currently finishing the fifth group. In all, 500 organic pigs, born and raised at WCROC, have gone through the feeding trials.
Gabriella reported that she and Megan Kavanagh recorded and calculated the pigs’ individual weights, feed intake, average daily gain (ADG), average daily feed intake (ADFI) and feed/gain (F/G). The pigs spent 10-13 weeks on the feed trial, and were harvested once they reached 270 lbs.
In this study, Gabriella and Megan used a new identification and weighing technology called LeeO. Pigs were tagged with an ultra-high-frequency ear tag. Using an electronic reader on a long arm, a Bluetooth enabled electronic scale head, and a tablet computer, the students scanned the pig’s ear tag as it entered the scale; the scale connected with the tablet and recorded the pig’s weight on the tablet. This technology offers ease, accuracy and record-keeping simplicity to pig farmers who adopt it.
While data collection is still in progress, preliminary results are positive:
Economics of growing hybrid rye & feeding it to organic pigs
Master’s student Megan Kavanagh shared the costs and expenses that she and Dr. Lazarus determined from the 2022 & 2023 growing seasons and the first 300 pigs through the study. Organic rye grain and rye straw used in the project were grown in the project; organic corn, organic wheat straw, and organic soybean meal were purchased.The 2022 rye crop at WCROC yielded 104 bu/acre grain and 1.8 ton/acre straw. In 2023, the yields were affected by droughty conditions with a grain yield of 69 bu/acre and 1.0 ton/acre of straw.
Megan shared the production costs per acre of growing organic hybrid rye:
Rye growing costs (per acre)
Grain Costs
Fertilizer: $96
Machinery + Labor: $222
Rent: $132
Miscellaneous: $80
Total cost: $590/ac Straw Costs
Baling + Storage: $50/ac
$150/ton paid by WCROC 2022 + 2023
Carcass quality and taste test
Megan reported on the work done in connection with Dr. Cox at the UMN meats lab. From two groups of 100 pigs, sixteen 270-lb pigs were selected twice (Total= 32) for the carcass evaluation. 16 control pigs (8 barrows, 8 gilts) and 16 rye pigs (8 b, 8 g) were harvested at the UMN meats lab.Three objective measures were taken. Carcass pH was collected at 45 minutes and 24 hours post-mortem. Lower pH contributes to a brighter, redder meat color. Pork color was measured and the Warner-Bratzler shear force test was performed. Shear force is the force required to cut through a sample and is considered an indicator of meat tenderness.
Two subjective measures were taken: Color and marbling scores.
There were no significant differences in pH at 45 minutes or 24 hours between control & rye pigs. Shear force measurements were not significantly different, either. There was a higher objective color measurement in the control pigs, indicating a lighter colored meat.
Subjectively, there were no significant differences in the color or marbling scores between control & rye pigs.
The UMN Food Science and Nutrition Sensory Center at St. Paul provided 73 taste test panelists 18 years and older. The Likeness ratings were a 120-point scale which evaluated the overall liking, liking of flavor, and liking of texture. The Intensity ratings were a 20-point scale which rated juiciness, toughness and off-flavor. Panelists were provided a sample of cooked pork loin, unidentified between control and rye pigs.
The Likeness ratings of overall liking, flavor and texture were comparable between rye and control pigs. In the Intensity ratings, panelists judged the rye pork to be tougher compared to the control pork. To summarize, replacing 50% of corn with hybrid rye did not negatively impact pork quality and consumer eating experience.
Organic Support Partners
This project was funded by a 3-year USDA Organic Ag Research & Extension Initiative (OREI) grant and continues as the final group of pigs are currently being fed.Additional support for the project was provided by Forever Green Initiative (FGI) at the U of MN and the Midwest Transition to Organic Partnership Program (TOPP). TOPP is just beginning and is an outreach to connect transitioning organic producers with mentors. More information can be found at organictransition.org.
Matt Leavitt from FGI shared with attendees at the field day current opportunities available to transitioning organic farmers. Additionally, Matt created a Forever Green Initiative technical bulletin about hybrid Rye using data from this project. https://z.umn.edu/FGIryeTechBulletin
What’s next? A team representing the UMN WCROC, UMN- Morris and the UMN-Twin Cities has received an OREI grant to develop an organic agriculture curriculum, and the project is currently underway!
Diane DeWitte is an Extension Educator based in Mankato. She can be reached at stouf002@umn.edu.
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