URBANA, Ill. - Spring is here and we are starting to get the gardening itch, said a University of Illinois Extension horticulture educator.
“Warm days tease us and blooming crocus encourages us,” said Martha Smith. “But we know Mother Nature is still in charge and she can release her fury at any time. Now is the time to start thinking about what will need to be divided in our gardens.
“In general, most perennials need to be divided every three to five years. The ideal time is in the spring just as active growth starts. It is at this time you can do the least amount of irreparable damage. All systems are go! The plants are coming out of their dormancy and are primed for growing,” she said.
Some may argue that there are specific plants that respond to dividing better at later times during the growing season. “Yes, that is true. The recommended time for oriental poppy, peony, and Siberian iris is late July or early August, but spring is still okay if that is the only time you can divide,” Smith said.
Divide early spring bloomers after bloom and they will have all season to anchor new roots and set buds for next spring. Divide summer-fall bloomers in spring and they too will be able to set roots and respond to daylight and temperatures to bud and flower. For the majority of perennials in the garden spring is a great time for dividing
Usually a plant will show signs of needing division. They become overgrown with dead, unsightly centers, or their vigorous growth has sent them to places in your garden where they are not welcome! Plants often have fewer or smaller flowers and are in overall poor health due to the plant depleting the fertility of the soil as it crowds itself.
“Let the plant be the gauge and not a calendar,” Smith said. “Some perennials may need dividing every two years while others may not need any attention for seven years.”
To divide mature clumps of perennials, lift the clump and separate the outer active growing portion from the center. Discard the center and replant the active growth areas. Be careful not to over-divide. Leave a proportionate amount of roots to crown. Too few roots will not be able to support a large crown. Too small a crown will not give you much of a visual display. Too large a clump may mean you’ll be dividing this plant again soon.
“Don’t worry about being rough,” she said. “Some perennials need a backhoe and a pickaxe! After lifting these brutes, use a saw or a sharp flat-edged shovel. On the softer side, some perennials lift very easily and you can actually separate them with your hands.”
Replant the portion you are keeping and discard or give away the rest. Prepare the planting area by adding compost or aged manure. Remember, a perennial can be expected to live in that spot for several years so take a few minutes and amend the planting area. You will be glad you did.
“You should stagger your plant divisions so that the whole garden will not need dividing at the same time,” she said. “A good three-to four-year-rotation plan will yield a nice display of flowers each year.”
Integrating perennial grasses for sustainable agricultural systems webinar
URBANA, Ill. – The North Central Regional Center for Rural Development (NCRCRD) will host a webinar on the future of perennial grass-based sustainable farming systems featuring speaker DoKyoung (D.K.) Lee, a University of Illinois production agronomist, on Tuesday, March 11, at 12 p.m. (CDT).
The event is part of the center’s Innovations in Agriculture and Rural Development free webinar series designed to help business owners and entrepreneurs to learn more about technology that may be relevant to current or future business operations.
Lee will discuss sustainable agricultural systems integrated with perennial grasses; how to design and establish market potential; a case study; and an on-farm example.
According to the NCRCRD website, the future of agriculture could include a perennial grass-based sustainable farming system within its landscape that will encourage environmental services, decrease use of fossil fuels and chemical products, improve diversity of plants and animals, generate more locally grown foods and bioenergy feedstock, and improve farm profitability. Biodiversity within agricultural landscapes will promote productivity and sustainability of our agriculture through food, feed, fiber, and fuel.
Spring salad at your front door
URBANA, Ill. - Mesclun is a mixture of assorted small, baby salad leaves also known as a mesclun mix. You can purchase mesclun bagged in cellophane at your grocer. Yet freshly harvested from a few square feet in your patio, garden, or front stoop, mesclun is an easy tender treat, said a University of Illinois Extension horticulture educator.
“What flavors are in the mix? Arugula, mustard greens, and chicories have a strong peppery flavor,” said Nancy Pollard. “Endive presents a peppery bitter note. Radicchio has a combination sweet-and-bitter taste. Some describe spinach as mineral in taste, but sweet when young. Sorrel has a tart, tangy acid taste like a lemon or sour green apple.
“Any one of these alone can be overpowering. Yet mixed with an equal quantity of mild lettuces and a simple dressing, they present a pleasing layering of flavors to savor,” she said.
While they do best in full sun, these greens will grow nearly as well in light shade. Plant the salad seed mix in March to early May when soils reach about 40 degrees F. These cool-season greens are sweetest when grown in cool weather. Plant again in August or September as cool late summer and fall nights favor them as well.
“You could grow these in a half barrel or other container while waiting to plant warm-season flowers or veggies,” she said. “And they only take a few weeks and a few square foot of soil.
“Lettuces often sprout in about a week. Other greens will take about two weeks to germinate so you can sow them separately if you wish and then mix them at harvest. You could also purchase a mesclun seed packet that is premixed. Sow only as much as you and your family will eat in a week, and then if you have space, repeat every week two or three times to have new baby salad coming on over the whole season.”
All of these greens have small seeds that are best sown on the surface of loosened soil. If growing the seeds in a pot, Pollard recommends moistening the soil first so the seeds aren’t washed away when trying to moisten the soil.
Next sprinkle the seed about a half-inch apart, and then cover with only about one-quarter inch of soil. Some suggest you practice sowing fine seed on a paper towel first until you get the feel of distributing the seed evenly about one-half inch apart. Then mist to thoroughly moisten the top dressing of soil. Keep seeds moist but not soaking during the germination time. Birds sometimes like to harvest the seed before they sprout so consider covering them with netting if you think feathered visitors might be tempted.
“Start harvesting your crop when the greens reach just 2 or 3 inches tall, often in only a month or so,” Pollard said. “Don’t let them get more than 5 or 6 inches tall before snipping them off with scissors for your salad. If you cut them about an inch above soil level, most often the crowns will re-sprout.
“Water and a light fertilizer after harvest will bring on additional delicate greens from the remaining crowns. If you used slow-release fertilizer in the potting soil, you will not need to add more fertilizer unless it is a fall planting and you have used the soil all summer for other crops. With a little planning, you will have this fresh salad available at your doorstep,” she said.
It's National Nutrition Month: Enjoy the taste of eating right!
If you are struggling to keep your New Year’s weight loss resolutions alive, March is a great month to get back on track. It’s National Nutrition Month, and this year’s theme, “Enjoy the taste of eating right,” reminds us that we all have different food preferences. The challenge lies in making the foods we like nutritious so we don’t feel as if we’re depriving ourselves.
“People need to lose the idea that there are two categories of food; good food and bad food,” said U of I Extension nutrition and wellness educator Natalie Rodakowski. “When we put foods into these categories, we become so restrictive that we crave bad foods and our weight loss goals become unachievable.”
So it’s time to find a way to make the “bad” foods on your list healthier while making the “good” foods on your list taste a little better. Taste will always trump nutrition; but this practice gives all foods in either category a level playing field in the game of food choices.
“For example, let’s take a basic favorite food category like desserts, and everyone’s least favorite food category, vegetables, to see how we can enjoy the taste of eating right,” she said.
Ways to make desserts healthier
It’s hard to maintain a healthy routine when your sweet tooth makes its presence known at 7 p.m. There’s nothing wrong with craving a cookie now and then, but something has to give! If you get creative in the kitchen, desserts don’t have to spoil all the hard work you put in that day.
- Fruits can be a delicious dessert. Haven’t had any fruit today and its already past dinner? Fruits are naturally sweet and might curb your craving. Try putting your favorite artificial sweetener on strawberries or add raspberries to vanilla ice cream.
- Recipe substitutions can go a long way. Instead of eggs, use egg whites to reduce the amount of cholesterol in baked goods. Substitute half a recipe’s sugar with an artificial sweetener to reduce the sugar content and retain the sweet flavor. You can also substitute half the flour in your recipe with whole-grain flour. Finding a substitute that works for your baking might take some experimentation, but you don’t have to use all healthier options. Just find one that leaves your treats still tasting delicious.
- Try dark chocolate. Dark chocolate is actually good for you! It has several chemical compounds and antioxidants that can affect your mood and cognitive health. Studies show that eating a small amount of dark chocolate two or three times each week also helps lower your blood pressure.
- Add walnuts to your cookies. Walnuts are a great way to get Omega-3 essential fatty acids, especially if you don’t enjoy fish oil or seafood. Omegas 3s have been linked to the reduction of cardiovascular disease.
- Add chocolate to your milk. Who says you can’t be a kid again? If you’re craving chocolate, add a little chocolate to your milk to get your craving under control while also getting your vitamin D and calcium for the day.
Ways to make vegetables taste better
Children and adults tend to turn up our noses at the sight and smell of vegetables. Let’s face it, they have a bad reputation, and you may think they don’t taste as good as their other “vegetable” friend, the french fry. Try thinking outside the box when it comes to our green enemies. The way you prepare this essential food group can make all the difference in your vegetable intake.
- Spice them up! Try adding herbs in place of salt. Garlic, basil, rosemary, chives, or parsley—the options are endless. Herbs will bring your vegetables to life!
- Add cheese. Just a touch of parmesan or melted cheese might do the trick. Be careful not to overdo your cheese and veggie combos because cheese calories can add up.
- Dip your raw vegetables. Raw vegetables are a little difficult to eat alone. Choose a light or low-fat dip when snacking or eating them as an appetizer. Again, make sure your vegetable isn’t drowning in a sea of ranch dressing. Just a little will do the trick.
- Hide the vegetables. This is one of the oldest tricks in the book. If you can’t see them, they aren’t there. Try adding kale into your smoothies or veggies into your baked goods! If you don't like the taste of many vegetables, incorporate them into soups or casseroles Each bite will have many flavors and you’ll taste more than vegetables.
- Olive oil. Just a spoon full of olive oil will help the vegetables go down! A couple of tablespoons of olive oil helps herbs stick to vegetables and is a healthier alternative to butter. A favorite way to eat baked asparagus is with olive oil, garlic powder, and a touch of parmesan cheese.
So rip up your good and bad foods list and find small, simple, realistic ways to have your cake and eat it too. As part of the National Nutrition Month campaign, the Academy of Nutrition and Dietetics website includes a variety of promotional tools, recipes, tips, games, and helpful resources designed to send the message of healthy nutrition. To learn more about how you can enjoy the taste of eating right, visit www.eatright.org.
Hog prices take off, probably due to PED-V
URBANA, Ill. – How large are the losses of baby pigs due to PED-V (Porcine Epidemic Diarrhea Virus) and how will the losses reduce slaughter supplies this spring and summer and for the rest of 2014? According to a Purdue University Extension economist, no one knows the correct answer, but lean-hog futures market participants seem to have decided that the losses will be very large for slaughter supplies this spring and summer. In the past two weeks, April lean-hog futures have risen by $10.68 and June futures have risen by $6.10 to record highs.
But, have market participants over-anticipated the magnitude of losses due to the PED virus?
“So far this year, the number of animals coming to market has been very close to the number indicated by the USDA December Hogs and Pigs Report,” said Chris Hurt. “When adjusted for the number of slaughter days compared to last year, the slaughter count so far is down about 0.5 percent. However, market weights have been higher by about 2.5 percent, resulting in total pork production being up about 2 percent. Year-to-date hog prices have been close to those in the same period in 2013.
Hurt said that the lean-hog futures market has extremely high price expectations for the March through July period this year, apparently due to expectations of small slaughter supplies due to PED-V losses. Projected lean-hog prices for that period using futures closes on Feb. 28 suggest expected prices averaging near $105 per hundredweight, compared to $86 for the same period one year ago. If low supplies are thought to be the cause, this is suggesting that market participants believe that hog slaughter supplies could be down 7 to 10 percent during this time period. This also assumes that other factors, such as low beef supplies, are also factored in.
How does this potential 7 to 10 percent anticipated decline in slaughter numbers stack up against the USDA December inventory count?
Hurt said that second quarter 2014 supplies will come primarily from the under 50-pound pig count on Dec. 1, which was down about 0.5 percent. Thus market participants may be anticipating that many of those very young pigs, which were in inventory on Dec. 1, ultimately died due to PED-V.
“Third-quarter 2014 supplies will be drawn heavily from winter farrowings, and this is where numbers get very uncertain,” Hurt said. “Winter farrowing intentions were up 1.3 percent, but because PED-V kills baby pigs, the number of pigs weaned per litter could be down sharply. This is what no one knows for sure. One helpful reading from the USDA inventory survey was the number of pigs weaned per litter during the fall 2014 farrowing. That was about 2 percent lower than the trend weaning rate.
“The impact of PED-V is thought to intensify in cold weather so the loss of baby pigs could be higher than 2 percent during the period of November 2013 to March 2014,” Hurt said. “Again no one knows the impact on a national basis, but lean-hog futures participants may be expecting losses to be as high as 7 to 10 percent. If the actual impact is closer to 3 to 4 percent, then futures prices may ultimately have to adjust lower. Great uncertainty continues for the size of the spring pig crop. Farrowing intentions were also up somewhat over 1 percent, although the impact on death losses from PED-V are expected to moderate as weather warms. All great uncertainties eventually get resolved in the marketplace. For the hog market, this will occur as we see the actual number of slaughter hogs coming to market from March through July this year,” he said.
The bigger question is how PED-V will impact the economic returns for the entire pork industry in 2014. The initial answer may be somewhat surprising. Hurt said that the PED-V will likely increase economic returns if those returns are measured across the entire U.S. industry. Why?
“The demand for pork is relatively inelastic, and this means that when there are short supplies, consumers are slow to adjust consumption downward,” Hurt explained. “As a result, prices will tend to increase by at least 2 percent for each 1 percent that the quantity of pork drops. This means that total revenue in the industry will likely increase due to PED-V and more than offset the losses from the disease.”
Hurt added that the outcomes of individual producers will likely vary as higher revenues from increased hog prices are compared to the financial losses due to death loss. Those who have death losses from PED-V that are very severe (having PED-V losses that are greater than the national average) will probably have net financial losses. Those individual producers who have average death losses from PED-V will likely be better off as the revenue increase may be bigger than the PED-V financial losses. Of course, those who have no or only small PED-V death losses will be better off as the increased revenue due to higher hog prices is more beneficial than the small PED-V financial losses.
“At the farm level, current futures markets are suggesting a live price for 2014 at a record high of $73 per hundredweight compared to $64 last year,” Hurt said. “This will provide record-high industry revenues and the highest profit per head since 2005.”
Who is going to pay for these record-high pork producer revenues?
“Unfortunately, the consumers of pork are expected to be large net losers from PED-V as they will have to pay record-high retail pork prices and also have less pork availability,” Hurt said.
Early composting helps soil and plants later
URBANA, Ill. - New gardeners often ask, “What is compost and do I need to buy it?”
When starting a new garden, it is hard to imagine we should initially spend more time, money and energy on compost than on plants, said a University of Illinois Extension horticulture educator.
“It is plants we want,” said Nancy Pollard. “Yet without adequate compost (decomposed organic matter) in the soil, the plants won’t thrive. It is the soil that provides nutrients, and the compost that holds adequate water and provides good drainage to make the difference between just surviving plants and the thriving plants we covet.”
Good soil, that is soil with a good amount of organic matter, will hold lots of water available to plants, yet drain well so roots stay healthy. Soil can hold roughly 1.5 quarts of water per cubic foot of soil for each percent of organic matter. So increasing the organic matter content from 1 to 2 percent would increase the volume of water to 3 quarts per cubic foot of soil, or at 3 percent to 4.5 quarts of water.
“What a difference that extra water makes in times of drought stress,” she said. “It is the difference between needing multiple applications of water per week compared to only needing additional water every week or two. So adding compost in the beginning saves you time and money and gets you much better plants in the long run.”
In a very small garden, work the organic matter in with a spading fork ($50- $100) or for a larger garden, invest in a broad fork (about $200), Pollard recommends. Many gardeners prefer the broad fork to a rototiller, as the broad fork aerates more deeply, preserves soil structure, brings up fewer weed seeds, cuts up far fewer earthworms, requires little maintenance, and is less costly and less jarring.
How much compost should be added?
Pollard recommends that for 100 square feet of soil, add one (or a proportional combination of) the following:
- 8 cubic feet of peat moss; OR
- 15 cubic feet of compost; OR
- 4 bushels (about six 5-gallon buckets) of grass clippings. (Do not use lawn clippings from grass that has been treated with sprays containing fungicides, insecticides, or herbicides.)
When most un-decomposed organic matter is added to the soil, microbes begin decomposing the carbon materials, utilizing soil nitrogen in the process. In order to compensate for this nitrogen loss when using un-composted straw or leaves, you will need to apply supplemental fertilizer containing nitrogen. For 100 square feet of soil, add either one bale of straw or four bushels of leaves, as well as, in either case, 1 pound of nitrogen fertilizer (to help microorganisms break down organic matter).
Adding organic matter in the fall is best and the spring is second best. Any time of year is better than not doing this, Pollard cautioned.
“I did not say add garden soil or potting soil to your garden unless you are making raised beds,” she noted. “If using raised beds, create a soil and compost mix with up to a maximum of 50 percent compost by volume. So you likely don’t need more soil in your garden, you likely need more compost.
“Why are those extra quarts of water made available by organic matter important? Water is critical because plants use water to maintain plant turgor (hold them up). Water aids in cell division and growth; water provides pressure to push roots through soil; water is required in photosynthesis to make carbohydrates; water moves food and minerals around the plant; and water is critical for stabilizing plant temperatures,” Pollard said.
Lots of compost initially and top dressing with compost annually means the plants will likely have adequate water available and won’t be stressed so easily. The plants will flourish, and the gardener will be proud and proclaim they have a green thumb! Interesting that brown matter (compost) is what makes for a green thumb!
Raised bed checklist
URBANA, Ill.- The idea of putting in a raised-bed vegetable garden can be confusing if you’re not sure where to start, said a University of Illinois horticulture educator.
It can be especially difficult for schools and communities that have never put in gardens before. Spring is a great time to start planning for this year’s garden, said Candice Miller.
“A checklist can be helpful in putting in a raised-bed garden,” Miller said. “The list below can help you work through all the steps of putting in a raised-bed garden, from selecting a location for your raised bed, all the way through planting your bed.”
Step 1: Choose a location
- The location for a raised bed should be in full sun for most fruits and vegetables.
- It should be near a water source for easy watering and should be close to the building for convenient harvesting.
- The bed can face any direction, but if you are building a longer bed, orienting the bed east and west will provide better light distribution.
Step 2: Kill off existing vegetation where your raised bed will go
- Grass and weeds can grow up through the new bed so it’s best to kill off any existing grass and weeds prior to putting the soil in the bed.
- This can be done naturally by placing plastic, cardboard, or layers of newspaper down over the vegetation. This will eliminate all light from the plants and will kill off the growth over a few months’ time. This can be done in the fall so that the area is ready for spring planting. Newspaper or cardboard can be left at the bottom of the bed as it will degrade, but plastic should be removed prior to placing soil in order to not impede the drainage of your bed.
- Another method is to spray the existing vegetation with a herbicide, like glyphosate, to kill all existing vegetation. Follow the safety and application instructions on the product label.
Step 3: Choose your construction materials
- Raised beds can be constructed out of just about anything. Some of the most popular choices include redwood or cedar wood, concrete blocks, bricks, stone, and various recycled materials.
- Redwood and cedar are some of the longest-lasting woods for building raised beds.
- Some materials you want to avoid include some treated lumbers (read more about treated lumbers here: http://pubs.cas.psu.edu/freepubs/pdfs/uc173.pdf), creosote-treated railroad ties, and chemically treated pallet wood. Avoid any type of material that may be dangerous for food products to come in contact with. If these materials are used for bed construction, the bed may be lined with plastic to avoid contact of the materials with the soil.
- Choose whatever material will be the most economical and long lasting for your bed.
Step 4: Build your bed
- The size of the bed will depend on the number of people the bed will provide with food.
- Beds should be no more than 4 feet wide if accessible from both sides and 3 feet if accessible from one side. The length of the bed can be as long as needed.
- The depth of the bed should be at least 6 to 12 inches to promote good root growth.
- Beds built higher than 18 to 24 inches will need extra reinforcement.
- At least a 4-foot-wide pathway between beds is standard for easy accessibility. This pathway can also be covered with mulch, straw, newspaper, etc., to prevent weeds. It can be planted with grass as long as the pathway is large enough to allow a mower to pass through.
Step 5: Fill your bed with soil
- The soil used for the bed should include good topsoil and lots of organic matter. This can be any combination of: purchased topsoil, compost, fine pine bark mulch, or peat moss.
- A soil mixture example could be: 60 percent topsoil, 30 percent compost, 10 percent soilless growing mix that contains peat moss, perlite, and/or vermiculite.
- Various websites have soil calculators available that can tell you how much soil is needed for a certain bed size.
- It’s recommended (though not required) to test the soil using a soil test kit prior to planting and in years following to monitor pH and nutrient levels.
Step 6: Plant your bed
- Nearly anything can be grown in a raised bed. Cucurbit crops like melons and cucumbers may be better suited to a larger site though as they quickly fill a bed.
- Plant spacing is very important in a raised bed so that prime planting space is not wasted. Consult your seed packet for information on proper spacing. Information can also be found on U of I Extension websites (http://web.extension.illinois.edu/vegguide/step02.cfm) and in various books about ways to maximize planting space.
- Be sure to place taller vegetables on the appropriate side of the bed to prevent shading of other plants in the bed.
Visit the Illinois Vegetable Garden Guide website by U of I Extension for more information on raised beds and vegetable gardening: http://web.extension.illinois.edu/vegguide/.
NRES Master's Defense by Jack Pizzo
N-527 Turner Hall, 1102 S. Goodwin Ave., Urbana, IL
NRES Master's Defense by Jack Pizzo
Title: Green and Natural Spaces in Your Community A Guide to Living with and Managing Naturalized Landscapes and Natural Areas
Sustainability (green infrastructure, wetland mitigation, sustainable landscaping and ecological restoration) has influenced site design and land management for the last 25 years. It has been my experience that land owners, public and private, have a limited knowledge of the reasons, costs, responsibilities, and benefits. As such, many of the projects failed to meet their goals and owner expectations. To date there has been no single non-technical publication to explain sustainability, and the science behind it, to the owners. The purpose of my project was to create a publication that explains the need for sustainability through engaging the owners’ professional and/or personal values. The goal was to provide a resource that will help any person develop a good understanding of the importance of sustainability in the landscape as well as support current and future projects.
Beware the infected bargain plant
URBANA, Ill. - Buying bargain plants at the garden center can be very tempting, but before buying that marked-down plant, it’s important to give it a good inspection, said a University of Illinois horticulture educator
“Usually when a plant is marked down, it’s either because it is toward the end of the season for that plant or because there is a problem with that plant,” said Candice Miller. “Some of these problems may include various diseases or insects that are infecting the plant that could then spread to other plants in your home or garden.
“Using some inspection techniques can help you decide whether that plant is a quality plant to purchase,” she added.
First inspect the leaves and stems of the plant closely. Look on the upper and lower sides of the leaf checking for any symptoms of insects feeding on the plant or for any sign of disease. Signs of insect feeding could include a sticky, shiny substance on the upper leaf surface, possibly caused by aphids. Or there may be white fuzz-covered insects called mealybugs that have attached themselves to stems or leaves. All are common pests that can infect potted plants.
Look for any browning, spotting, or wilting of leaves as well. “Those symptoms may be due to improper watering, but they may also be signs of other problems or disease,” Miller noted.
The root system is also important to inspect. Carefully turn the plant over and gently remove the root ball from the pot. Check to make sure roots look white and healthy and have formed a solid root ball that does not fall apart when pulled out of the pot. “Large circling roots may be a sign that the plant has been in that pot for an extended period of time and roots that are darkened and look diseased may be a symptom of disease problems,” Miller said.
As mentioned, the other reason a plant is marked down is simply because the season has ended for that plant. Amaryllis bulbs, for example, are commonly sold during the holidays as a kit that includes the bulb, soil, and a container. “I went through this inspection process myself recently at a garden center,” related Miller. “I love amaryllis so a 90 percent-off amaryllis bulb is hard to pass up. Upon inspecting the bulb, though, I noticed that the bulb had already begun to grow inside the package and there was mold growing on the bulb, likely from being in a moist, warm package for too long.
“If I had purchased that bulb kit, I likely would not have had success in getting it to grow and bloom. It was an example of when plant inspection pays off,” she said.
The next time you’re tempted by a bargain plant, be sure to give it a good inspection.
“If the plant passes inspection and is growing happily and healthily, that plant may be worth the reduced price as long as the planting time is still appropriate,” Miller said.
Beneficial anti-inflammatory effects observed when plant extracts fed to sick pigs
URBANA, Ill. – Porcine reproductive and respiratory syndrome (PRRS) is the most expensive and invasive disease for pig producers on a global scale. Though it is not occurring on every farm, it is the biggest disease problem in the pig industry, said a University of Illinois animal sciences researcher.
E. coli has also been a problem historically and continues to be on an industry-wide basis, said James Pettigrew. “Either disease can sweep through a farm so their alleviation would substantially reduce production costs. Even though many management practices have been used in the swine industry, these practices cannot guarantee freedom from disease for pigs,” he said.
Consumer concerns about bacterial resistance to antibiotics have prompted the swine industry to seek additional methods to protect the health of pigs, including special feed additives. This interest led Pettigrew and his team to explore the potential benefits of selected plant extracts
The researchers conducted two experiments to test the beneficial effects of adding plant extracts to pig diets to combat PRRS and E. coli. In both experiments, researchers used four diets in weanling pigs, including a control diet and three additional diets that included garlic botanical extracted from garlic, turmeric oleoresin extracted from ginger, or capsicum oleoresin from pepper. In both experiments, half of the pigs in each dietary treatment were challenged with either E. coli or PRRS virus while the other half of the pigs were non-challenged.
“We’ve known for a long time that plant extracts, also called essential oils or botanicals, have certain biological actions,” said Yanhong Liu, a doctoral student who led the studies. “For instance, they can act as antioxidants or as antimicrobials. We wanted to test whether we could get a benefit from feeding those products in very low doses to pigs that were challenged with these specific diseases.”
E. coli, a bacterial illness of the gut, is marked by diarrhea, decrease in appetite, decrease in body weight, and in some cases, a higher mortality rate. E. coli is especially dangerous post-weaning as pigs adapt to new feed and new environments, Pettigrew said.
The pigs in the study challenged with E. coli that had been fed any of the three plant extracts had a lower frequency of diarrhea (20 percent) than the pigs fed the control diet (40 percent). The pigs fed plant extracts were more efficient (40 percent) in feed use than the pigs fed the control diet in the E. coli-challenged group, and challenged pigs fed plant extracts had sounder gut morphology compared with the challenged pigs fed the control diet.
Liu noted that even the pigs in the non-challenged group, with a low frequency of mild diarrhea, benefited from the plant extracts. “Because there is a relatively high diarrhea rate in post-weaning pigs as they are moved from the mom and started on all solid feed, the extracts could also be used to reduce its occurrence,” she said.
Common symptoms of PRRS, a viral infection of the lung, include fever, lethargy, trouble breathing, loss of appetite, and decreased growth performance. The disease can also lead to spontaneous abortions and higher pre-weaning mortality rates in pigs.
After feeding the pigs challenged with the PRRS virus the three plant extracts, the researchers observed that the pigs were more efficient in week 1 (55 percent) and week 2 (40 percent) than the pigs fed the control diet. The pigs continued eating and gaining weight. They found this to be especially true with turmeric, Liu said.
When they checked blood samples from the pigs with the PRRS virus, they found that the pigs fed plant extracts also had a lower blood viral load (13 percent) and lower concentrations of inflammatory mediators than pigs fed the control diet. These observations also suggest that feeding plant extracts could suppress ongoing inflammation and prevent secondary infections.
The researchers believe the benefits resulted from the effects on the pigs’ immune systems because feeding plant extracts reduced the inflammation caused by E. coli and the PRRS virus.
“In production animals, inflammation is costly. Inflammation reduces feed intake, and it diverts nutrients away from growth to the immune system,” Pettigrew said, “If we can bring that quickly back down to normal after a challenge, then that helps in production.”
Although previous studies have looked at using plant extracts in pig diets, Pettigrew said Liu’s study, which looked at the effects of three different extracts on two different diseases, had not been done previously. He also added that the low concentration of the extracts used while still producing beneficial results set this study apart.
The researchers will continue to study the mechanisms behind the beneficial effects they observed, including conducting gene expression studies. “We want to know the big picture of how these plant extracts affected the challenged and non-challenged pigs,” Liu said.
“Dietary plant extracts alleviate diarrhea and alter immune responses of weaned pigs experimentally infected with a pathogenic Escherichia coli” was published in the November 2013 issue of Journal of Animal Science and can be accessed online at http://www.journalofanimalscience.org/content/91/11/5294.full. Co-authors of the study were Liu, Pettigrew, M. Song, M. Che, J.A.S. Almeida, J.J. Lee, D. Bravo, and C.W. Maddox.
“Dietary plant extracts improve immune responses and growth efficiency of pigs experimentally infected with porcine reproductive and respiratory syndrome virus” was published in the December 2013 issue of Journal of Animal Science and can be accessed online at http://www.journalofanimalscience.org/content/91/12/5668.full. Co-authors of the study were Liu, Pettigrew, T.M. Che, M. Song, J.J. Lee, J.A.S. Almeida, D. Bravo, and W.G. Van Alstine.
Pancosma SA, Geneva, Switzerland, provided funding for the research.