Page 12—PouHry Note* Supplement to Lancaster Farming, Saturday, Sept 23,1995 Special Report \ Lancaster Farming I —V i—l « I IkJ®® FUES UNDERSTANDING THE PROBLEM FINDING A SOLUTION Charlie Pitts Professor Of Entomology Penn State » Agricultural production con tinues to change with the econom ics of size, demanding more ani mals and land in today’s farming operations. With the increases in animal numbers, situations have deve loped which can create conflicts between farmers and homeowners who live in agricultural production areas. Some of these conflicts include odors, use of pesticides, movement of trucks, and machin ery on secondary roads, and flies. Flies have taken advantage of ideal environments in and around animal facilities to breed and populate in large numbers. At times, the flies create nuisances to neighbors, especially when man ure, laden with large quantities of pupae and larvae, is spread. (With some fly populations resistance to today’s insecticides, IPM integrated pest manage ment activities must be deve- POULTRY MEAT TENDERNESS (Continued from Pag* 6) balance and of great economic importance to the meat bird industry. Part of the phenomenon of shrinkage that occurs during the feed withdrawal period is a loss of moisture, which is associated pri marily with muscle tissue in the body. As feed withdrawal time increases, expressible moisture in breast muscle decreases and ten derness declines. Prolonged feed withdrawal will also reduce muscle glycogen stores, which are necessary for proper development of many of the post-mortem changes that occur in meat that contribute to its tenderness and “juiciness.” Glycogen, a form of stored carbohydrate in animals that is similar to plant starch, provides a framework for holding water in skeletal muscle, and helps to retain moisture in the tissue. In addi tion, glycogen breakdown is integral to the pro cess of rigor mortis and its resolution in post mortem muscle tissue. After the bird is slaughtered, readily available energy in the form of ATP and phosphorylcrea line in muscle is depleted and the muscle fibers develop a state of extreme rigidity called rigor. When this occurs after death, the condition is called rigor mortis. If the rate at which ATP depletion in muscle occurs is increased, cold shortening is prevented and tenderness increases. This can occur with electrical stimula tion of deboned meat. Once ATP is depleted, gly cogen begins to be metabolized under conditions that result in the production of a metabolic acid, lactic acid, that lowers the pH of the tissue. This process takes approximately four hours in broiler breast muscle (which is considerably faster than occurs in beef), and if the meat is deboned earlier than this, it is toughened. During the second phase of rigor mortis (termed resolution), naturally occurring enzymes called proteases that break down pro tein structure degrade the muscle fiber or myofi brillar protein matrix, resulting in increased meat tenderness. Increased tenderness of deboned broiler breast meat occurs between 24 and 72 hours of refrigerated aging. One group of loped and used to solve the problem.) Flics need organic matter (man ure, food wastes, poorly managed compost piles, etc.) that has 50-70 percent moisture to lay their eggs. These areas must be near a food source with bedded animal packs, calf hutches and kennels, and poultry layer houses with in house manure storage providing the best environments. But even if fly numbers increase around farm facilities, neighbor complaints do not normally occur until manure is spread. When adult flies emerge, they head for the closest white and warm object, which is normally a neighbor’s house. A female fly is capable of pro ducing up to six batches of 75 to 200 eggs at 3 to 4 day intervals. Larvae (maggots) hatch in 12 to 24 hours. In 4-7 days and three growth stages, larvae grow into pupa (dark reddish-brown cigar shaped case and about 1/8-inch long). Generations overlap, with all stages present at the same time. The entire cycle can be as short as ten days if temperatures are 85 degrees, and 45 days at 60 degrees F. Solutions: With more large ani mal facilities, especially poultry layer operations, more flies are enzymes responsible for the struc tural breakdown of the muscle fib er protein, the cathepsins, are acid proteases, and their activity or effectiveness is enhanced at low pH (high acidity). The lactic acid produced by glycogen metabolism enhances the activity of cathep sins, and thereby promotes the resolution of rigor and increased tenderness. In addition to the above pre- and post-slaughter events that can present in our rural areas. With insecticide resistance, flies have become a problem. Two areas are receiving major concentration: using IPM in the buildings to keep fly numbers at reasonable levels and properly handling manure once it leaves the facility. Two three-year grants from the Pa. Department of Agri culture, one to study manure treat ment ($94,000), and the other to study in-house IPM activities ($113,000) have been received to address these problems. In conjunction with the two grants, the following activities are under way: evaluation of tillage methods and their effects on keep ing larvae and pupae from emerg ing. Early findings from this study showed plowdown to be somewhat effective. Moldboard plows were the most effective, chisel plows were next in effectiveness, and dis- affect tenderness, the conditions under which the product is held for storage and transport can also affect quality. Freezing of muscle tissue and subsequent thawing results in the formation of ice crys tals that rupture the muscle fiber membrane and cause seepage of fluid. Moisture retention and pro duct “juiciness” and yield are therefore improved if the product is held at temperatures above freezing throughout the period from slaughter to sale. s ■S I I RADIANT... Innovative Class of Brooders Shenandoah Manufacturing Co., Inc. FAX: 800-434-3068 PO Box 839, Harrisonburg, VA 22801 USA PH: 540-434-3838 Dr. Charles Pitts Shen king did not stop emergence of flies. Covering manure with plastic is also showing some promise. To test this hypothesis, poultry man ure was dumped in windrows, one dump truck wide, then black plas tic was placed over the pile. A lay er of soil was placed on the ends and edges of the plastic to seal the pile. In two field trials, the ends of die plastic were uncovered at 8 and 14 days, with no live larvae, pupae, or adult flies observed. A consideration is to clean the house at 7 day intervals, then seal the manure under plastic. If cover ing and sealing the manure under plastic kills all development stages of flies, then manure can be spread at any time without fly problems. This would eliminate the cost of incorporating afterspraying, as well as other fly IPM activities in the house. Baited fly barrels have shown success in capturing adult flies. These topless 55 gallon drums are fitted with a screen cone with a hole in the bottom. Cone sides are overlapped over the barrel edges and are tightly secured. Bait is placed in the barrel. When attracted to the bait, flies enter the trap through the hole. Once in the barrel, they cannot find their way back to the hole and thus out of the barrel. These traps have been placed around calf kennels and hutches, feed bins and exhaust fans of layer houses. The ideal bait is still to be deter mined. Dead birds work well but create a pungent odor around the barrel. It also brings more than houseflies to the barrel. Unwanted milk, and a mixture of feed and water has also worked well. Adding water initially and on a regular basis to all (or additional milk in milk baited barrels) bait is essential. Two gallons of water or milk per week in the summer months is necessary. Hie number of barrels per facility and type and replacement of bait needs more on farm investigation. Parasitic wasps play an impor tant role in poultry IPM programs and are helping reduce fly popula tions in high-rise poultry houses. The parasite is less than 1/16 inch long. The female wasp lays eggs in the pupal case and kills the deve loping fly. You must introduce a Booth #44 Northeast Poultry Show ■ Warms your flock from floor up. ■ Achieves fuel savings compared to space heaters. ■ Provides sufficient output for periods of extreme cold. high number of waSps in the house to accomplish reduction. Mulchers have been used to help lower number of pupae in concen trated areas such as in manure pits in high-rise layer houses. As larvae develop, they migrate to a dryer area to pupate. In cage layer/pullet houses, manure will form a cone shaped pile with pupae maturing at the edges. A mulcher pushed down the rows will draw in pupae and kill them. This activity has helped especially after clean out and before natural enemies to flies have been reestablished. Keeping manure dry is a key element. Leaks in waterers are the major source of wet manure (per fect place for flies to lay their eggs) and should be checked daily. Dry manure will cone and with proper ventilation proper drying will occur. This deters flies from breed ing and promotes development of beneficial mites and beetles. It is essential to monitor fly populations. Posting white 3x5 cards on a weekly basis at different areas will show fly level numbers. These cards can help determine what IPM activities are required. The common housefly has found an ideal home in some of our farm facilities. Dealing with flies today takes more than an occasion al spraying. Finding ways to lower fly numbers and stop neighbor conflicts is important to the agri cultural industry in Pennsylvania. Details of the above studies will be presented in later issues. If you need information, please call Charlie Pitts at Penn State, (814) 863-7789. Egg Gathering System (choice of single & dual belt)
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