The University of Georgia College of Agricultural & Environmental Sciences
Cooperative Extension Service
Upcoming Livestock Dates
Georgia Beef Expo Planned
Grass Tetany Season
Gaining Perspective on Waste Nutrients from Pork Production
Georgia Holds First Pig Futurity Show in the Southeast
Comparisons of EPDs Within and Across Breeds
Why Use Minnows in Catfish Ponds?
The Truth about the Safety of Feeding Poultry Litter to Cattle
1997 Calhoun Bull Evaluation Center Report
Nutrients and Feeding Practices That May Be Responsible for Developmental Orthopedic Diseases in the Horse
Please give credit to the author if you use an article in a non-Extension publication and please send a copy of the article to the author. Thank you!
Mark A. McCann
Extension, Research Instruction Coordinator, Animal and Dairy Science
|February 7||Cumming Junior Beef Show
Contact: Ian Cowie, County Extension Agent
Forsyth County - 770/887-2418; e-mail: firstname.lastname@example.org
|March 3||Tifton Beef Cattle Shortcouse||Irwinville|
|March 4||Tifton Bull Sale||Irwinville|
|April 2-4||First Annual Georgia Beef Expo||Perry, GA|
|February 13-14||Monty Roberts Clinic and Symposium
Georgia International Horse Park
General Admission: $25.00, VIP Tickets - $60.00
Call 888-826-6649 or Cindy Hertel (VIP Tickets) - 770/860-4195
|February 21||Georgia 4-H Junior National Benefit Horse Auction
Contact: Gary Heusner - 706/542-7023
|February 28||Georgia Horse Council Annual Horse Farm and Membership Meeting - UGA Vet School||Athens|
|March 4-5||Equine Reproduction Short Course - UGA
Contact: Gary Heusner - 706/542-7023
|American Horse Council Convention
Hyatt Regency on Capitol Hill
Charles A. McPeake, Animal and Dairy Science Industry Liaison
The first annual Georgia Beef Expo is set for April 2-4, 1998, in Perry, Georgia. Sponsored by the Beef Breeds Council of the Georgia Cattlemen's Association, the Georgia Beef Expo will be the "premier marketing opportunity for Georgia seedstock breeders," according to Chuck Sword, Expo Chairman. The three-day event will include beef cattle shows, parades, displays, auctions and a trade show of livestock farm supplies and equipment.
Fifteen cattle breeds are committed to the first Expo. Participating breeds include Angus, Beefalo, Beefmaster, Brangus, Charolais, Gelbvieh, Limousin, Maine Anjou, Polled Hereford, Red Angus, Salers, Santa Gertrudis, Senepol, Shorthorn, and Simmental. A club calf sale will also be held for junior show prospects.
Shows and parades will begin at 9:00 a.m. on Friday, April 3, and will continue through Noon on Saturday, April 4. Two auction rings will see action beginning Noon on April 3 and will continue through 6:00 p.m. on April 4.
Shows and sales for each breed will be managed by the respective state or regional breed association. Out of state and international inquiries are welcomed.
For more information on consigning or for sale catalogs, contact the breed association of the Georgia Cattlemen's Association, P. O. Box 24510, Macon, GA 31212; Phone: 912/474-6560; E-mail: email@example.com
Mark A. McCann, Extension Coordinator, Animal and Dairy Science
Late winter and early spring is usually the peak period for the occurrence of grass tetany in lactating beef cows. Grass tetany is caused by inadequate levels of magnesium, and is affected by high levels of calcium, phosphorous or potassium. The condition can be controlled by adding magnesium oxide to the mineral mix. About 25 grams of magnesium daily should provide protection against grass tetany. About half of the daily intake should come from the feed and half from the magnesium containing mineral mix. The following is a good basic magnesium-based mineral mix which can be mixed on the farm.
A mature cow needs to consume 2-4 ounces (60-120 grams) of the mineral mix daily. With this level of intake, a mature cow will receive 0.6-1.2 ounces (18-36 grams) of magnesium oxide daily. Magnesium oxide is about 60% magnesium so cows will receive .4-.7 ounce (11-22 grams) of magnesium daily from the mineral mix. In most situations this should control grass tetany. When using the mineral mix, remove all other salt sources from the cattle's diet. If a hot mix (SBM or CSM + salt) is being used as a protein supplement, Magnesium oxide can be added at the necessary level where each cow should receive approximately 1.0 ounce/day in the mix.
Commercial mixes are also available for preventing grass tetany. Commonly called high-mag blocks or mixes, these should contain 11-13% magnesium. For the small cattleman, it is usually more practical and easier to purchase a high-mag material than to mix individual ingredients.
Monitoring consumption of any magnesium supplement is important to insure that cattle are consuming the supplements at a level to provide protection. Because magnesium is an unpalatable mineral, salt and the oil meals are added in effort to increase consumption. Occasionally higher than 20% meal is required to get cattle to consume the needed 2-4 ounces. Some commercial Hi-Mag mineral mixes use dry molasses to increase palatability. It is a mistake to believe that lower than expected consumption is due to lack of need on the cow's part. More than likely it is an indication of the palatability of the mineral mix.
Other than palatability, low mineral consumption can be caused by poor mineral feeder placement or an inadequate number of mineral feeders for the number of cows. Locate these feeders in high traffic or loafing areas and provide one feeder per twenty cows. This will enable cows at the bottom of the herd pecking order to consume enough minerals.
High-mag materials are necessary only during high risk situations. The chance of grass tetany is greatest under warm, rainy conditions in late winter or early spring. Forages most likely to produce tetany are winter annuals and fescue. High levels of fertilization, especially with poultry litter, increases the problem. The increased risk at higher fertility levels is a function of the high potassium content of lush forage. There is no advantage in using high-mag minerals during the rest of the year. Start offering the Hi-Mag minerals 21-30 days prior to the critical period and stop after the pasture forages in question put up a seed head.
Dr. Rick D. Jones, Professor and Extension Animal Scientist
It is time to place some factual perspective on the subject of waste nutrients produced in production of pork. It is difficult to generalize about many waste nutrient values but the non-scientist, the average individual concerned about the environment, needs to have some basic facts to consider when evaluating modern pork production in their community. The following is a simplistic look at the key facts.
Nitrogen in a gaseous form is inert and makes up about 78 percent of the air that we all breathe. However, in the form of nitrate or ammonia, nitrogen can be an environmental problem. Homeowners typically put 130 to 300 lb of nitrogen per acre per year on warm season lawns. Nitrogen is found in the waste of pigs as a product of the breakdown of proteins which normally support growth of nutritious, lean pork. A major goal of pork production is to minimize the amount of waste nitrogen because it is the single most expensive component of the pig's diet.
Phosphorus is another nutrient of concern in pig wastes mainly because it is often the limiting factor in growth of certain plants such as algae in lakes and ponds. If too much phosphorus is released in our surface waters, algae grow extremely rapidly causing eutrophication, low oxygen levels and fish kills. Phosphorus found in corn, the base feed source of pigs, is poorly digested and utilized by the pig. Therefore, we typically add phosphorus to the diet in other more digestible forms. It is also a goal in pork production to minimize the amount of phosphorus in wastes because phosphorus is an expensive component of the diet.
Two other nutrients needed in animal diets are also considered potentially troublesome in pig wastes, zinc and copper. Although they are only required in trace amounts, these minerals are critical for growth and health of the pig.
The main goal of waste management in pork production is to minimize the amount of nutrients which escape the pig's digestive system, but then to optimize the recycling of those waste nutrients into plants as new proteins, etc. Currently, most waste management regulations are based on using wastes to provide the nitrogen needed by plants. This determines the amount of land and crops required for spray fields or nutrient recycling. Much scientific evidence recommends a move to phosphorus-based regulations to avoid over-applying phosphorus. Pork production operations with Land Application System Permits from the Georgia Environmental Protection Division are required to have a plan designed by a licensed Professional Engineer (PE) and approved by federal Natural Resource Conservation Service (NRCS) personnel. Spray field size, location and ground water monitoring wells are prescribed by this permitting process.
It should be noted that the goals of human waste treatment facilities or municipal sewage plants are quite different than in pork production. Since most water from these facilities is returned to streams or rivers, the nitrogen, phosphorus and biological oxygen demand (BOD5) and total suspended solids (TSS) must be greatly reduced by the treatment system used.
In human waste systems, we must minimize all organic matter including critical nutrients, but with hogs, the valuable nutrients are used for a productive purpose, to support plant growth. These totally different goals are a reason that it serves little purpose to compare the manure output of hogs and humans.
Georgia's most common producer of organic nitrogen waste, the broiler chicken, uses a dry, wood-shavings based litter system for nutrient recycling. In lagoon-based waste systems typical of pork production units, irrigation of the lagoon effluent is used to transport nutrients to the crop fields. This water based system does not add nutrients and BOD5 as with the litter-based system. Therefore, it does not require as many acres of crops to utilize the organic matter and nutrients as poultry manure.
The table to the right gives some estimates of the major nutrients included in animal manures. The estimates for nitrogen from anaerobic lagoon effluent for a 1000 sow farrow-to-wean operation is 5,200 lb per year, compared to 12 times that amount for a farrow-to-finish operation.
It is important to understand the relative quantities of waste and waste nutrients produced in the various stages of a modern pork production system. Because of health advantages and other production efficiencies, the most popular model for pork production is currently the three site production system. Large numbers of sows are housed in one general location for breeding, farrowing and weaning. An industry standard of 4,800 sows per housing system is becoming common due to various efficiencies.
Pigs are weaned at two weeks of age (12-19 days) at an average weight of about 12 pounds. As shown in the graph, the farrow-to-wean portion of the production system uses 12 to 13% of the feed and produces only 8 to 9% of the waste nitrogen of the entire farrow-to-finish process.
These light weight pigs are easily transported to the second site or nursery stage which involves growth of the pigs from 12 lb to 45 lb or the feeder pig stage. This phase represents 8 to 9% of the feed and due to the high protein diets typically fed, 14-16% of the waste nitrogen is produced. The nursery is often responsible for much of the odor of pig production. The feeder-to-finish stage of production takes pigs from about 45 lb body weight to market weight averaging 250 lb. This stage involves 78-80% of the feed and 75-76% of the nitrogen waste.
Georgia is rapidly becoming a sow state which means that many pork production companies are considering placing farrow-to-wean operations in the state. The advantages of mild weather and lower production facility costs encourage producing the two week old pig here for shipment to a second site closer to Midwestern hog finishing facilities for the nursery stage. The final stage of production is then completed where feedstuffs are much cheaper and competing pork processing plants provide competitive prices for market hogs. An additional advantage of this system is that most of the wastes will be produced near major grain producing sites for better use of waste nutrients.
Bainbridge Ag Department
History was made on the Southeastern show pig scene on January 10, 1998 as the Ringmaster Extravaganza Pig Show was held at the Georgia National Fair and Agricenter in Perry, Georgia. This was the first pig futurity ever in this area and included pigs from Georgia, Alabama, and Florida. This first show had 221 pigs exhibited with high hopes of even more entries next year.
After Mr. Mark Hoge of Iowa State University was finished placing the pigs, John Paul Martin of Bainbridge FFA stood as Overall Champion and received a set of Paul Scales compliments of the show and Mr. Adrian Paul, as well as $300.00 and a beltbuckle from Morgan Livestock. Reserve Overall Champion was exhibited by Dillion Pool of Sylvester, GA and he received a set of clippers, a clipper box and guards compliments of Showstopper Supplies, Pinehurst, GA., plus $150.00 and a beltbuckle from Jessie Ponder. Elizabeth Mulkey of Bainbridge was chosen Grand Champion Progress and she received a beltbuckle and $300.00 courtesy of Perry FFA, and Megan Marchant of Hazlehurst, GA was named Reserve Champion Progress, and received $150.00 and a beltbuckle from Alton Andrews.
Congratulations to the Decatur County Young Farmers and Ringmaster for their organization of this event, and good luck on next year's Southeastern pig preview!
The following is a list of the pigs placing first in each class. There were no second place pigs; instead these were co-winners in each class and all class winners came out for the division championship.
Class 1 - Jordie Hundon, Toombs Co.; Ryan Varnedoe, Appling Co.
Class 2 - Victoria Hill, Miller Co.; Jodee Clark, Colquitt Co.
Class 3 - Sarah Taylor, Colquitt Co.; Stephen Morgan Jr., Dooly Co.
Class 4 - Jana Donnlson, Decatur Co.; Kiley Stewart, Decatur Co.
Class 5 - Teryn Tucker, Colquitt Co.; Robert Bray, Johnson Co.
Class 6 - John Paul Martin, Decatur Co.; Mary Bea Martin, Decatur Co.
Class 7 - Dillion Pool, Worth Co.; Matt Marchant, Jeff Davis Co.
Class 8 - Steven Roberts, Worth Co.; Jordie Herndon, Toombs Co.
Class 9 - Lauren Burton, Mitchell Co.; Elizabeth Mulkey, Decatur Co.
Class 10 - Brandon Boone, Jackson Co.; Jason Sapp, Terrell Co.
Class 11 - Megan Marchant, Jeff Davis Co.; Heather Williford, Mitchell Co.
Class 12 - Danny Hudson, Irwin Co.; Jacob Pool, Johnson Co.
Class 13 - Layne Peacock, Houston Co, AL; Teryn Tucker, Colquitt Co.
Class 14 - Libbi Stiefel, Calhoun Co, AL; Jessica Peacock, Houston Co, AL
Ronnie Silcox, Extension Animal Scientist
Comparisons of EPDs with a given breed are fairly straight forward. All of the major breed associations list EPDs for birth, weaning, yearling and milk. Within a given breed, the difference in EPDs between any two bulls or any two cows indicates the difference you would expect to see in their offspring if they were similarly mated.
For example, Angus Bull A has a weaning EPD of +35 and Angus Bull B has a weaning EPD of +30. If these two bulls were bred to similar cows you would expect Bull A's calves to weight about 5 pounds more at weaning (35-30 = 5). Comparisons of any two animals within a breed is done by simply looking at the difference between their EPDs.
The next question a breeder might have about the bulls above is "Just how good is a +35 Angus?" In the case of Agnus cattle all comparisons are based on the average animal born in 1977. An EPD of 0 is the average EPD of all Angus cattle born in 1977. The base year on Angus is 20 years ago and Angus cattle have changed over the last 20 years. What the breeder probably really wants to know is how does a +35 Angus Bull compares to an average Angus NOW?
Table 1 lists the average EPD for all animals born in 1995 within each breed. This table does not mean anything in terms of how one breed compares to another. Base years are different and breed evaluations are different. What Table 1 does tell you is where the current breed average is. In the case of Bull A with a +35 pound weaning EPD, the Angus breed average for 1995 born cattle is 25.3. This bull is about 9.7 pounds above current average (35 - 25.3 = 9.7).
The next question commercial breeders have is "How do breeds compare on performance in a cross breeding program?" Table 2 probably gives the best summary of current research. At the Meat Animal Research Center (MARC) in Clay Center Nebraska, a crossbreeding project has been going on since the early 1970's. Birth, weaning and yearling weights were recorded on crossbred calves out of predominately Angus-Hereford cross cows. Data on calves produced by each breed of bull were adjusted for the EPDs of bulls used. This table should reflect the expected weights of calves produced if average 1995 bulls of each breed are used on crossbred cows under the management system in central Nebraska. This is based on crossbreeding work done at one location, but it is probably the best research available on how breeds rank against each other.
The next question is, "Can I compare EPDs across breeds?" EPDs do not compare directly across breeds, but given the information in Table 2 and the average values in Table 1, scientists at the Meat Animal Research Center have come up with across breed adjustment factors listed in Table 3. They have taken the differences in sire breeds observed in the MARC crossbreeding project and adjusted for differences in bases across breeds. For the purpose of across breed comparison, they have used Angus as the base breed. To use Table 3, simply add the adjustment factor for the breed listed to the Animal's EPD. Do the same for the animal of another breed, then compare. For example, an Angus bull has a +7 birth EPD. A Hereford Bull has a +3 birth EPD. Using adjustment factors listed in Table 3, the Angus bulls across breed EPD is +7 + 0 = 7. The Hereford bull's across breed EPD is +3 + 4.7 = 7.7. Bred to similar cows you would expect this Hereford bull to produce calves that are .7 pound heavier than those produced by this Angus.
The final important question is, "Just how good are these across breed EPDs?" Nobody really knows. Across breed comparisons are based on data from one research herd in one location.
Some caution needs to be used in making vast assumptions using Table 2 and Table 3. Breeders want to compare breeds for use in crossbreeding programs. Used with caution and the realization that these are rough estimates, adjustment factors in Table 3 provides a method for comparison across breeds.
|Table 1. 1995 Average EPDs for Each Breed|
|1995 All Animal Non-Parent Average EPDs from 1995-1996 Genetic Evaluations|
|Breed||Birth Wt. (lbs.)||Weanling Wt. (lbs.)||Yearling Wt. (lbs.)||Milk (lbs.)|
|Table 2. Average Weights of Calves Sired by Various Breeds at MARC Adjusted for Sires' EPDs to a 1995 Birth Year Basis.|
|Breed||Birth Wt. (lbs.)||Weanling Wt. (lbs.)||Yearling Wt. (lbs.)||Milk* (lbs.)|
|*Expressed in pounds of calf above or below average of breeds listed.|
|Table 3. Factor to Adjust EPD to Angus Base|
|Breed||Birth Wt. (lbs.)||Weanling Wt. (lbs.)||Yearling Wt. (lbs.)||Milk (lbs.)|
Gary Burtle, Aquaculture Specialist, UGA, Tifton, GA 31793-0748
Minnows in catfish ponds may be a great idea. Although catfish have traditionally been raised alone or with only a few grass carp to control weeds, the fathead minnow can be beneficial by controlling diseases and possibly improving pond water quality. The fathead minnow is currently being investigated as a biological control for the catfish disease called "Proliferative Gill" or "Hamburger Gill." So far the fathead minnow is able to control the disease and be compatible to catfish culture.
Proliferative gill disease in catfish can cause total loss of catfish in a pond that is affected. A protozoan parasite is released from a small aquatic worm and that parasite enters the catfish gills to cause tremendous damage which usually kills the catfish. Like other freshwater fish parasites, this disease poses no threat to humans. However, proliferative gill disease is more common in ponds that are recently constructed and therefore threatens new fish producers. Since no chemical control measure has been found that would stop the disease without harming the catfish, study on biological control methods was begun at the University of Georgia in 1993.
The fathead minnow is a small dark plump minnow that is popular as bait for crappie fishing. Some fishermen call it the "Tuffy" minnow because it is able to survive a long time in a bait bucket or on a fish hook. Fathead minnows eat a diet of small insects, worms, algae, and zooplankton. They grow to about three inches in length. Therefore, they are always at the right size to eat the small aquatic worms that spread the proliferative gill parasite.
Fathead minnows keep the numbers of aquatic worms low compared to populations in catfish ponds without the minnows. Stocking 10 pounds of minnows per acre can reduce aquatic worm populations in about two months. Over a growing season, those minnows will spawn and reach up to 300 pounds of minnows per acre in addition to the catfish production.
So far, the small populations of aquatic worms that live in ponds stocked with catfish and fathead minnows have not produced serious proliferative gill disease outbreaks. Although the presence of any aquatic worms could allow some of the proliferative gill disease parasites to grow, conditions necessary for proliferative gill disease epidemics have not been observed when 1,500 to 3,000 fathead minnows per acre were present. This control method costs $30 to $50 per acre of catfish pond and is usually a one time cost since the minnows will reproduce in the catfish ponds. That cost would be spread out over three to five years since most ponds are not drained until several batches of catfish have been raised.
Additional potential benefits of stocking fathead minnows include improving providing a live food for catfish and improving pond water quality. Catfish, especially the larger catfish, have been known to eat fathead minnows. Some catfish producers have had fathead minnows in their ponds for years. Fathead minnows eat small particles of waste catfish food and algae. Future research at the University of Georgia will investigate their effect on pond water quality and whether they can reduce the accumulation of algae in ponds.
Gary Burtle, Aquaculture Specialist, UGA, Tifton, GA 31793-0748
When all counts are in, more than 520 million pounds of channel catfish will have been processed in 1997. This is the highest production ever and a 10% increase over 1996. Since the catfish industry started rapid growth in the 1970's the industry has grown from a few million pounds to the current level at a rapid clip averaging more than 18% per year. The consumption of catfish by the American consumer has increased in the traditional catfish-eating areas like the South and South-west but also in non-traditional areas including the North-east and West coast. Farm-raised catfish is now an acceptable alternative for many species of seafood that are not available in quantities that can supply the consumers' appetite for fish.
In Alabama, Florida, and Georgia, the catfish industry has grown over the past two years. New catfish acreage is providing nearly 10,000,000 more pounds of catfish than in 1995. Catfish has never been easier for consumers to buy than today. Grocers and restaurants that carry catfish products are nearby to almost everyone in the Tri-state area. Tri-state area catfish production is high quality and allows local markets to buy the fresh catfish throughout the year.
Although the catfish industry is expanding, our local processors are struggling to compete and survive. Catfish processing has a reputation for being very difficult, especially as processors grow and seek regional and national markets. Yet small processors have been successful in the past and some continue to be viable today. Key characteristics of successful catfish processing plants include skilled and careful management, adequate pricing to recover costs, adequate catfish supply for year-round sales, and low overhead. Matching capabilities to market and supply must be based on realistic observations of the local catfish industry. If a complete package does not exist for the catfish processing plant, every effort must be made to fill in the gaps in supply, processing or sales. For example, several catfish processing plants in the Tri-state area are located too far from catfish producers to overcome the logistics involved in obtaining a year-round supply of catfish.
Some assistance to catfish processors can be obtained from the following sources:
The Cooperative Extension Service, Alabama, Florida, and Georgia
Alabama Farmers Federation
Alabama Development Office (800-248-0033)
Florida Department of Agriculture and Consumer Services Bureau of Seafood and Aquaculture (904-488-0163)
Georgia Farm Bureau Marketing Association (800-342-1196)
Georgia Department of Agriculture
Matthew H. Poore, Ph.D., Department of Animal Science, North Carolina State University, Raleigh
Recently the use of processed poultry litter as a feed ingredient for cattle has been challenged. Broiler litter has been used for over 50 years as a feed with no major problems reported. It is usually used as a feed for stocker cattle or brood cows in poultry producing areas of the country, where it is of significant economic importance. It has also been used in feedlot rations in some areas, but not to the extent to which it is used in cattle not soon to be used for human consumption. Litter is never used in the diets of lactating dairy cows. The feeding of litter is regulated on a state by state basis by state feed control officials.
Ruminants are ideally suited to using byproducts and waste products as feeds because of their unique stomach (the rumen) where feed is exposed to microbial fermentation before passing on to the rest of the digestive tract for digestion and absorption. Ruminants, including beef cattle, have been fed byproducts, including processed poultry litter, for many years. Feeding litter to beef cattle is beneficial to many beef producers, and to society in general because;
Litter is composed of poultry manure, feathers, bedding and spilled feed, and is an economical source of protein, minerals and energy. Like many byproduct feeds, some specialized management is needed for litter to be a useful feed. While litter does not contain E. Coli 0157:H7 (the pathogen of most recent concern in the beef industry) poultry do shed pathogens such as Salmonella, and they are sometimes present in fresh unprocessed litter. The U.S. poultry flock could also eventually contract E. coli 0157:H7, so its potential presence in litter in the future should not be ignored.
Other potential problems with litter include the possibility that litter could conceivably contain pesticide residues from insect control used in the house, and residues of feed additives used in poultry diets. Litter may also contain foreign objects such as hardware and glass, and it has also been suggested that litter could contain mycotoxins (especially aflatoxin). Another concern has been that litter contains low levels of heavy metals such as arsenic and copper. Because of these concerns, care must be taken to manage litter in the poultry house and then process it before it is made into a cattle feed. Also, as litter is not a "nutritionally balanced" feed, it needs to be used as an ingredient in a mixed diet for the best results.
Before feeding, it is recommended that litter be stacked, covered with plastic, and allowed to heat for at least 3 weeks. Experience has shown that litter usually needs to be stacked 6 to 8 feet high, and contain 70-80% dry matter (20 to 30% moisture) to achieve proper heating. The internal temperature should reach 130 degrees F which improves the palatability and eliminates any pathogens present. It is well known that if the heating time is short, such as with cooking, a much higher temperature is needed (160 degrees F). The extended heating time in a deep stack allows for killing of pathogens at a lower temperature. Another desirable method of processing litter is to pellet or extrude it. This form of processing achieves a very high temperature (200 degrees F) in a short period of time, which eliminates pathogens but doesn't damage feeding value.
Ammonia is also present in litter, and its bacteriocidal activity provides additional protection against the survival of pathogens. Covering the stack will keep a high level of ammonia at the surface of the stack which may achieve a lower temperature than the core. Covering the stack will also prevent overheating (above 160 degrees F) which damages protein and carbohydrates, greatly reducing the feeding value of the litter.
Research conducted at Auburn University showed that 130 degrees F was sufficient to kill Salmonella and E. coli 0157:H7 when they were seeded into litter and placed in a deep-stack1. In recent research conducted at the University of Georgia, 86 poultry litter samples from commercial farms were analyzed for nutrients as well as microbes, and no Salmonella or E. coli 0157:H7 was found in any of the samples2.
For many years commercially processed poultry litter has been used in California in feedlot cattle diets, and in the diets of developing dairy heifers. In a summary of analyses for pathogens, pesticides and heavy metals conducted by the California Department of Food and Agriculture no major problems were identified3.
Litter is not the only ingredient that could potentially contain pathogens as all feedstuffs contain bacterial populations. Extensive research has been done to determine the effects of heat and ammonia on the survival of pathogens in litter and other feed ingredients4,5, 6. Heat is very effective at killing pathogens, and the lower the temperature, the longer it takes to kill the organisms. Based on this research, the heat generated at the core of a deep stack, and the ammonia released during the process, should be more than adequate to reduce pathogens to low risk levels after the recommended 3 week stacking period.
Heavy metals and drug residues have been researched in depth by workers at Virginia Tech. They have found no residues in beef to cause health concerns7. Arsenic and copper levels do increase in the liver of cattle fed litter, but the one of concern in humans, arsenic, returns to control levels within three days withdrawal. Most states recommend that there be a 15 day withdrawal period before slaughter to provide an added level of consumer protection. California, which had the first state regulations concerning the feeding of litter, dropped the withdrawal requirement because, in reviewing the evidence, feed control officials could find no scientific basis for requiring a withdrawal time3.
Pesticide residues may exist in broiler litter in trace amounts, but when fed to finishing cattle in balanced diets, no residues were found above levels considered to be safe8. The poultry industry has changed the types of pesticides it uses, and this poses an area of needed research, but in general these new generation pesticides are safer than the older ones they replace because the poultry themselves do ingest some of the litter, and residues in the poultry are also a concern. New drugs have been introduced for use in poultry since the time most of the research in this area was conducted, so this is another area that needs continued research activity.
It has been suggested that litter may have high levels of aflatoxin due to mold contamination. Mold counts in commercial litter were positive in a number of samples2. However, recent research9 has shown that litter actually has aflatoxin degrading capabilities, and can be stacked with high-aflatoxin corn, eventually eliminating the aflatoxin contamination. This may be due to ammonia, bacterial degradation, or both.
Review of the literature on feeding broiler litter indicates that it is one of the most researched byproduct feeds used, and that it is a safe feed for both the cattle and consumers. Based on scientifically sound research, and many years of experience, there is no reason to fear the use of processed broiler litter as a feed. Publications guiding producers on the safe and economical use of broiler litter in beef cattle diets are available from several states10, 11, 12, 13.
This article was reviewed by university beef cattle nutritionists from the major states using broiler litter as a feed for cattle.
Dan T. Brown, Extension Animal Scientist
The 28th bull evaluation test at Calhoun is now history. Consignors sent an excellent set of bulls to be tested. This test broke several long standing records. The 4.42 lbs. ADG (average daily gain) and the WDA (weight per day of age) of 3.50 were all time highs. The sale average was up $275.00 over the 1996 sale. This in general was representing the overall market turnaround.
Keep in mind that the Tifton Bull Sale is coming up on Wednesday, March 4, 1998.
The performance and sale information by breed averages were as follows:
|Breed||No.||On Test Wt.||Nov. 18 Wt.||112 Day|
|Breed||No.||Actual Final Weight||Adj. Yrlg. Weight||Adj. Yrlg. Hip Height||Ribeye Area||Back Fat||SC|
1997 Bull Evaluation Sale
|Breed||No. Sold||Total Sales||Average|
|7 Breeds||96 Bulls||$177,900.00||$1,853.13|
Gary Heusner, Extension Animal Scientist - Equine
Developmental Orthopedic Diseases refers to a number of orthopedic abnormalities that occur between birth and 18 months of age. Conditions considered to be part of Developmental Orthopedic Diseases (DOD) include (1) enlargement of the bone growth plates, (2) "wobblers syndrome," (3) angular limb deformities, (4) flexural leg deformities, and (5) joint cartilage damage resulting in a bone cyst or a loose piece of bone or cartilage in the joint (OCD or ostechondritis dissecans).
The clinical signs of DOD is reflected in the inability of the growing skeletal system to tolerate stresses imposed on it. There may be many factors causing DOD and these have been broadly categorized into genetic, environmental, and nutritional. Genetic conformation abnormalities may result in excessive stress on one or more parts of the skeletal system and uneven growth patterns. Genetically mediated metabolic abnormalities in the utilization of nutrients, enzyme activity, or hormonal control of the growth process may also be involved. Environmental stresses such as forced exercise, surface conditions of the ground, hoof trimming or shoeing and excess body weight may cause mechanical stress and trauma to bone and cartilage. Nutritional deficiency, excess, or imbalance of key nutrients will affect bone and cartilage in the growing horse. It is some of the nutritional factors that will be discussed as possible causes of DOD.
Energy intake influences the rate of growth. The more calories consumed per day the faster a young horse will grow. Bone development should be the primary concern of the young growing horse not deposition of fat. Excessive energy intake may include the development of DOD in three ways: (1) the rapidly growing horse puts more weight on the skeletal system at an early age, thus increasing the stress on immature bones. (2) Faster growth rates require high energy concentration of other nutrients important for tissue synthesis. (3) Higher energy intakes have been shown to alter normal hormonal secretions that influence cartilage cell growth and maturation. Most equine nutritionists agree that horses should grow at a moderate rate. Many times horses are grown rapidly (high energy intake) without a problem. However, it is imperative that protein and mineral intake match the energy intake and that the correct ratio of calories/protein, calories/calcium, calories/phosphorous, etc. be maintained.
Protein appears to have little direct affect on Developmental orthopedic Disease. It will affect growth rate. Excesses or deficiencies must be closely monitored as well as balance with energy and minerals.
Minerals are important as components of bone and as components of enzymes that are involved in cartilage synthesis and mineralization. Calcium and phosphorus make up approximately 35% and 18% respectively of bone mineral. It is not only important that adequate levels of calcium and phosphorous are fed but also a ratio of approximately 1.6 - 2.0 to 1 calcium to phosphorous be maintained. Another important factor is that excess levels of calcium should not be fed as excessive amounts over what is required may affect the absorption of other minerals.
The other minerals implicated in DOD are copper and zinc. Adequate levels are needed in the diet for cartilage synthesis and bone mineralization. Much has been written about adequate copper levels in the diets of young growing horses. Most rations formulated for young growing horses now contain 15 ppm or more copper and 60 ppm or more zinc which are above the minimum recommended requirements. It is very important that young horses fed a commercially or home made diet be fed one that is formulated to meet their mineral requirements and not fed a diet formulated for a mature horse.
To summarize, the following nutrients and feeding practices should have particular attention paid to them to prevent DOD in young growing horses.
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