NCSU Extension Swine Husbandry
A more printable version of Swine News in Adobe Acrobat.
December, 2000 . Volume 24, Number 11
AFFECTING ODOR BY DIET COMPOSITION: AN EXAMPLE
In the October issue of Swine News, the origin of odors was discussed, as well as how odors can be influenced by nutrition. In this issue, an experiment to demonstrate the role of nutrition in odor is described. This experiment was designed for educational purposes, and many of the experimental diets are thus not practical; instead, they were formulated to yield differences in odor production. These diets were:
- Control corn-soybean meal diet containing 17 percent crude protein.
- Control with 1 percent garlic powder.
- Control with 1 percent onion powder.
- High crude protein diet - 34 percent CP.
- Diet with fishmeal replacing soybean meal as the protein source.
- High-fiber diet - containing 25 percent soybean hulls.
- High-sulfur diet - feather meal replaces soybean meal as the protein source.
- Purified diet - mainly starch and casein.
- Control with 1 percent peppermint extract.
- Control with 1 percent dehydrated asparagus.
The diets were formulated to be nutritionally adequate, and each contained the same amount of protein, except for diet 4. Samples of feces and urine were taken after a 5-day adaptation period and mixed at a ratio of 2 parts of urine to 1 part feces. These samples were evaluated for their odor by Extension agents, graduate students, and faculty in animal science. Samples were scored on a scale of 1 to 8 for pleasantness, irritation, and odor intensity, with 1 being the best and 8 being the worst. The control sample (#1 in the list above) served as a standard for comparison and was assigned a value of 4.
As expected, diet composition had a significant impact on odor sensation. Diets containing fishmeal (#5) and high levels of sulfur (#7, through the addition of 12 percent feather meal) were considered to have the most unpleasant odor, as indicated by their high odor score. These data suggest that the sulfur content of the diet is a major determinant of the odorous nature of the manure, likely through the production of mercaptans, such as hydrogen sulfide and methylmercaptan. These compounds have an extremely low odor detection threshold (that is, the nose is extremely sensitive to them), and they do have an unpleasant smell (e.g., the rotten egg-smell is produced by hydrogen sulfide).
Manure from pigs fed the high-fiber diet (#6) or the purified diet (#8) was perceived as more pleasant than the control diet. High levels of fiber would be expected to reduce the digestibility of nutrients, increase endogenous losses, and therefore have the potential to increase odor formation. However, the opposite was true in this demonstration, possibly because of the use of a poorly fermentable source of fiber and the short duration of the experiment. Previously in Swine News, we reported that pigs require about 10 days to adapt to a high-fiber diet (made up of Bermudagrass), and in this experiment animals were given the experimental diets for only 5 days. It is likely the microflora had not adapted to the high-fiber diet. The purified diet, on the other hand, reduced odor, as was expected, based on the highly digestible ingredients of the diet, and left few nutrients for microbial degradation.
An interesting observation in of this experiment was the observation that there are substantial differences in how people perceive odors emanating from these manure samples. Evaluators were grouped according to their exposure level to swine manure in their daily activities as either high-exposure or low-exposure. For detecting odor sensation, both groups responded similarly (data not shown). However, in rating unpleasantness of odor (Figure 2), a clear group effect was shown.
Figure 2. Differences in pleasantness of odor judged by people with either low or high exposure to swine manure (the dotted line serves as the reference line).
The reference sample was set at a score of 4, as per the design of the study. Samples whose odors were considered more unpleasant by either group were rated significantly more unpleasant by the low-exposure group than the high-exposure group. This difference in rating between the groups became greater as the samples became more unpleasant. Thus, differences in exposure level to manure odors appeared to affect odor evaluation. People exposed to livestock odors on a daily basis, although equally perceptive of the odors, appeared to be more tolerant of the smell.
What this experiment shows first of all is that nutrition can greatly affect odor sensation. The pleasantness of the manure odor worsens by 60 percent for animals fed diets high in fishmeal or sulfur, compared to a purified diet. Also, it suggests that diets can be formulated to yield less odor than what is obtained with a standard corn-soybean meal diet. For example, by taking out indigestible fractions, an estimated 30 percent improvement in pleasantness is observed. Finally, excess sulfur should be avoided where possible.
This experiment also showed that the evaluation of odor is strongly dependent on exposure to odor. Those of us exposed frequently to swine odors notice this odor equally as strongly as our neighbors who experience swine odors less frequently, but those neighbors are more likely to rate the odor as more unpleasant. Although this finding is not necessarily surprising, it does show the difficulty of trying to reduce odor problems in the field.
—Eric van Heugten, Adam Moeser, Theo van Kempen
2002 NC PORK CONFERENCE SPEAKER PROGRAM
The educational program for the 2002 North Carolina Pork Conference will offer several unique opportunities and should provide a good mixture of formal and informal learning experiences on important topics. The annual pork conference is always a wonderful opportunity to bring our industry together, make and renew friendships, evaluate new products and learn the latest information. This year at the conference in New Bern there will be additional opportunities to get the latest information on virtually every facet of our industry. Educational programs will be offered on the second level of the conference center on both Tuesday and Wednesday. However, take notice that in an effort to make sure that Wednesday registrants can participate in all aspects of the conference the Wednesday educational program will start at 12:30 pm after the trade show closes. Registration for this educational program will begin at 12:15 pm.
The educational programs have been designed to meet both the unique structure of the North Carolina pork industry and the progressive nature of North Carolina's pork producers. There will be three different programs offered, each providing several speakers that will focus on topics that are important to producers. The first session is designed for managers and other people involved with pork production on a daily basis, the second is a forward looking session on legislative, environmental, and organizational issues for 2002 and beyond, and the third will present the latest information on animal waste management technologies and odor control.
Starting the program on Tuesday morning in the "Tips for Managing a Profitable Swine Farm Session" will be Dr. Glen Almond from NC State University. Dr. Almond will be discussing the importance of water in the breeding herd and various equipment and strategies that can be used to ensure the proper supply of this important nutrient while at the same time minimizing the amount of excess water that ends up in the manure treatment system. Dr. John Roberts, also from NC State University, will follow with a discussion that will cover the treatment, control and elimination of the PRRS virus. Dr. Roberts will discuss the latest research and clinical concepts that can be used when preventing or controlling this potentially devastating virus. A final highlight of this session will be Dr. Don Lay, Research Leader for the USDA's Livestock Behavior Research Unit. Dr. Lay will focus on management, care and housing practices that can be utilized to reduce pre-weaning mortality. Dr. Lay is internationally recognized for his work with animal behavior and management. In his talk he will provide an overview of the factors that contribute to piglet mortality and those who attend will be able to take home many ideas that can be readily applied for increased productivity and profit back on the farm.
Be sure to attend the Tuesday afternoon session, as it will provide important information and lively discussion at the "NC Pork Producer Town Meeting". In this forum legislative, environmental and state and national association updates will be presented. The NC Pork Council Annual Meeting will follow this session.
To allow everyone attending the conference to partake of all the activities this year, we will start the Wednesday educational program after the trade show concludes, at 12:30pm, with registration beginning at 12:15 pm. Attendees of the Wednesday afternoon session, "Managing Swine Waste in North Carolina", will receive three hours of continuing education credit for operators of animal waste systems. The most recent results of research trials on swine manure management and odor control will be presented by NC State University and industry researchers. These talks will be offered in one-hour blocks allowing participants to earn from one to three credit hours while at the annual conference. Dr. Mike Williams, Director of the Animal and Poultry Waste Management Center will provide an update on the evaluations of "Environmentally Superior Waste Management Technologies" under the Smithfield Foods and Premium Standard Farms Agreements with the NC Attorney General. This presentation will be followed by a more indepth description of two of the technologies currently under evaluation. Dr. Garth Boyd, Director of Environmental Programs for Smithfield Foods will present information on a system for gasification of swine manure for energy and ash recovery. Also in this session will be Dr. Theo van Kempen from NC State University, who will present data from his gasification project that proposes to convert swine manure to ethanol fuel.
In addition, everyone in attendance at the conference will receive a proceeding book containing papers from each session. I would encourage you to review the educational program and plan to attend the presentations that best meet your interests. I look forward to seeing you at the Pork Conference!
—Todd See
2001 MARKET HOG SHOW WINNERS, NORTH CAROLINA STATE FAIR
An outstanding set of market hogs was exhibited at the 2001 North Carolina State Fair. The Junior Barrow Show was divided into 11 classes and three divisions with 155 pigs weighing between 220 and 270 pounds. The show was held Friday morning, October 12, beginning at 9:00 a.m. Class winners in Division I were Caleb Sharp, Justin Lee, Earlie Byrum, Jr. and Rebecca White, with Rebecca White driving Division I Champion and Earlie Byrum, Jr. driving Division I Reserve Champion. Division 2 class winners were Lauren Hollis, Earlie Byrum, Jr., Collin Byrum, and Daniel Winstead. Daniel Winstead had the Division 2 Champion and Douglas Williams drove the Reserve Champion. Division 3 class winners were Lauren Hollis, Ryan Blalock, and Samantha Wiggins. Lauren Hollis had the Division 3 Champion and Ryan Blalock drove the Division 3 Reserve Champion. Judge Warren Beeler of Caneyville, KY, named Daniel Winstead's 254-pound pig out of class 8 the Grand Champion Junior Market Hog and Douglas Williams' 254-pound barrow out of the same class, the Reserve Champion Jr. Market Hog.
The Grand Champion Barrow sold for $5,000 to Harris Teeter in the Sale of Champions on October 13 and Harris Teeter also purchased the Reserve Champion for $4,500. In the sale at 3:00 p.m. in the Kelley Building 154 pigs were sold. Smithfield Packing floored the pigs at $41.00 per cwt., but N.C. Farm Bureau made every pig bring at least $150.00, while several pigs sold higher.
A new Senior Showmanship Class was held this year at 2:00 p.m. on Friday. With a lot of interest and a full ring of show persons, Norman Denning was determined the Champion and Lycurous Lowrey won Reserve honors.
The Performance Market Hog Show began at 2:30 p.m. Friday afternoon and attracted 67 pigs in five classes. These pigs were from a large group placed on test by producers in July and each pig carried it's average daily gain paint branded on it's rump. Class winners were Connie Byrum, Anthony Locklear, Earlie Bryum, Sr., A.C. Locklear, and Terri Locklear. Terri Locklear drove the Grand Champion on-foot while Earlie Byrum, Jr. showed the Reserve Champion. The Champion weighed 266 pounds and the Reserve weighed 238 pounds. The Reserve Champion on foot went on to place third in the carcass contest with 0.31 in. backfat, 8.51 square-inch loin area, and 0.983 pounds lean-gain-per-day-on-test. Collin Byrum won the carcass class with his fourth place pig in Class 3. This Champion went on test at 69 pounds and came off at 242 pounds with a 2.08 ADG, along with 0.34 inch backfat, 8.60 square-inch loin area, and 1.006 pounds lean-gain-per-day-on- test. The average figures for the carcass class were 243 pounds, 0.54 inch backfat, 7.01 square-inch loin area, and 0.777 pounds lean-gain-per-day-on-test.
The Open Barrow Show, held October 13, included 81 pigs ranging from 220 to 270 pounds, shown in 6 classes. Class winners were Connie Byrum, Bud Strohmer, Todd Brown, Hannah Haynes, Betsy White, and Albert Batchelor. The Grand Champion was a 256 pound pig out of Class 5, shown by Betsy White. Albert Batchelor drove his Class 6 winning pig, weighing 264 pounds, to Reserve Champion. The Grand Champion on foot was ninth in the carcass contest with 0.40 inch backfat, 7.85 square-inch loin area, and 61.20 percent lean. Betsy White won first and second places in the carcass contest. The Champion carcass measured 0.42 inches backfat, 8.91 square-inch loin area, and 63.57 percent lean. The Reserve carcass measured 0.45 inch backfat, 8.78 square-inch loin area and 63.39 percent lean. Carcass data was obtained in both the Performance Market Hog Show and the Open Market Barrow Show through Real-Time Ultrasound measurements by Todd See.
On Sunday afternoon, October 14, Russell and Elaine Wood were inducted in to the N.C. State Fair Livestock Hall of Fame. They exhibited purebred Duroc swine in the breed shows for several years until the breed shows were discontinued. They also entered pigs in the barrow shows and continue to do so with a third generation Wood exhibiting in the 2001 barrow show. Russell has also exhibited Angus cattle. For three or four years he was the swine show director.
The only pigs not in competition was the white sow and her 10 pigs on the porch of the Kelley Swine Building. Bruce Shankle was in charge of the swine shows. Some of the people assisting were Todd See, Bob Jones, David Lee, James Pope, W.G. Simmons, and Ron Hughes.
—James R. Jones
| Breeder | Address | Breeds |
| Bob Ivey* | 314 N.C. 111 S, Goldsboro 27530 | L, D, H, Y, CW, X |
| Wesley Looper* | 4695 Petra Mill Rd., Granite Falls 28630 | L, D, H, Y, X |
| Thad Sharp, Jr., & Sons | 5171 N.C. 581 Hwy., Sims 2788030 | D, Y, X |
| Tommy Spruill | Rt. 1, Box 149, Columbia 27925 | L, X |
| Swan Acre Farm | 1060 Main St., Swan Quarter 27885 | X |
| Thomas Farms | 8251 Oxford Rd., Timberlake 27583 | X |
| UCPRS (Swine Dev. Center) | Rt. 2, Box 400, Rocky Mount 27801 | X |
| *Real-Time Ultrasound | ||
—Frank Hollowell and David Lee
Last modified November 12, 2001.