NEWARK, De. Many swine producers are looking for ways to reduce energy costs in con finement operations. Natural ventilation may be one way to do this, says University of Delaware extension agricultural engineer James Scarborough. “Why not investigate natural ventilation to reduce fan and heater operation costs,” he suggests. “If your confinement building contains hogs weighing over 80 pounds, this can be used without detrimental effects on the hogs.” Natural ventilation works two ways in a confinement building. First, by wind blowing across an open ridge and drawing out warm moist air which is replaced by fresh air from side vents. Also, when the wind is calm, warm moist air inside the building rises with an effect similar to what occurs in a fireplace chimney. Temperature can be controlled by opening and closing shutters, curtains or windows as the need dictates. Scarborough says the best natural ventilation systems contain an automatic device controlled by a thermostat to open or shut curtains or shutters. “As long as the temperature remains between 50 and 80 degrees inside the building,” he says, “the hogs will be comfortable. Should it drop below zero degrees outside, you may need supplemental heat, especially if the building is not full. You also can allow the tem perature to fall if you feel you can tolerate the drop in production.” Except in the severest weather, he says the inside temperature won’t drop below 40 degrees. In the summer, temperatures above 90 degrees will require some with Onduline you DON'T HAVE TO TEAR OFF THE OLD ROOF TO PUT UP A NEW ONE In today’s economy, more and more farmers are re-roofing. And whether it’s re-roofing or new construction, Onduline saves you money. Onduline’s asphalt-impregnated panels are so lightweight, they can be installed right over your old roof, saving you time and labor costs. You’ll save energy costs, too, because your new double roof will provide added insulation. And Onduline lasts. Unlike metal roofing, it won’t rust or corrode. In fact, Onduline is so durable, it’s backed by the industry’s only Lifetime Limited Warranty.* * 25 years for commercial applications AREHDTSVILLE PLANING MILL ALLENSVILLE PLANING MILL INC. Gettysburg St. Arendtsville, PA 17303 717-677-6161 GEORGE W.AMEY SSSS 5 LEHIGH LUMBER POLE BLDG. WV. Richlandtown, PA 18955 6410 Airport Rd. 215-536-6880 Bethlehem, PA 18017 215-432-4511 WALTER & JACKSON INC. PO Box 168 Christiana, PA 17509 215-593-5195 Natural ventilation for swine buildings method of cooling the hogs, such as hourly mistings. During the three coolest months of the year, the specialist recommends using a supplemental fan to insure adequate fresh air when the building is completely closed, or when high winds preclude the use of natural ven- NEWARK, De. Breed a good sow at the right time to a fertile boar or two, and the next day there should be 16 to 18 fertilized eggs in her reproductive tract. But swine producers don’t often see litters that size. In fact, there aren’t many litters larger than 10 or 12 pigs, says University of Delaware extension livestock specialist Ken Kephart. Why should this be? “On the average,” he says, “40 percent of the embryos die during pregnancy. And about two-thirds of those are lost during the first month. Since these embryos are resorbed by the sow, you never know just how many died.” Research shows that several factors influence these losses, including environmental stress, nutrition, age of the sow, and uterine space. What can producers do to minimize embryonic death? “Treat your sows with a lot of respect especially during those first 30 days of pregnancy,” Kephart says. Avoid overcrowded conditions, for one thing. Researchers at the University of Illinois Agricultural Experiment Station found that overcrowding pregnant gilts I SMART FARMERS KNOW THE ANSWERS! 1 HOW? WHEN? The Lllcdme Roofing Main St. Allensville, PA 17002 717-483-6386 OR Kish Pike, Lewistown, PA 17044 717-248-9688 EWING ROOFING, INC. 2407 A Old Gettysburg Rd Camp Hill. PA 17011 717-761-6960 First month critical They Cover Their Investments with an Roof. Now, During the Onduline Factory $ 3.00 per sq. Rebate tilation drafts. because “Adequate insulation is a must in order to maintain a comfortable temperature range for the hogs," he says. “If you’re remodeling an existing warm confinement unit, the insulation will be adequate. Don't install a in the impairs the process of embryo attachment to the uterine wall. “Keep your sows cool, too,” he says. “It’s a fact that subjecting them to heat stress will kill em bryos.” Group sows at weaning, not at breeding. If they’re mixed at weaning, but the time they crane into heat the fighting will be over. That’s one less problem for the sow after she’s bred. If females need to be regrouped, wait until the second month of pregnancy, the specialist advises. Nutrition is also important in obtaining large litters. “Provide adequate nutrition, but don’t overdo it,” Kephart says. “During the first month, it’s probably better to underfeed than overfeed. There’s little evidence that nutritional deficiencies during this interval will affect embryo vaibility. But many studies show that full feeding gilts in early pregnancy leads to high prenatal losses.” Age of the sow makes a dif ference. Older sows generally lose more embryos than gilts, partly because they start with more. But as a sow reaches the end of her 'productive life, embryonic mor- SEE YOUR LOCAL OnduMnc The Lifetime Roofing DEALER TODAY CARTER LUMBER (PA 230-10) RD»3 Box 78 Rt. 230 Elizabethtown, PA 17022 717-367-1886 or 717-653-8310 MUMDIMHEI t SUPPLY CO. 157 E. Broadway Red Lion. PA 17356 717-244-4087 Ondulinc The Lifetime Roofing Route 9, Box 195, Fredericksburg, Va. 22401 call toll-free 800-368-6638 (in Virginia, 703-898-7000). building, but insulate between the rafters to allow air to flow up to the ridge opening.” excessive He recommends an insulation value of R-8 for the walls and R-14 for the roof. The insulation will control large temperature fluc tuations in the building and reduce fondensatinn after breeding sow tality increases and there’s a sharp drop in the number of pigs born a good sign she needs a new home. Uterine space is another factor. Even though the uterusl can be up to 8 feet long in a large sow, it can maintain only a limited number of pigs. The number of eggs shed can be increased by superovulating the female, but these efforts don’t seem to increase litter size at birth. How many pigs can a uterus support? Two separate studies conducted at the University of Illinois show that the average sow can carry up to 14 pigs before birth weight is significantly affected. “Since most sows start their RAM BUILDING SUPPLIES Box 6 Rt. 100 Eagle, PA 19480 215-458-5151 MUSSELMAN LUMBER INC. 200 Brimmer Ave. New Holland, PA 17557 717-354-4321 ARONE LUMBER Lucerne Rd. (Behind Halliburton's) Homer City, PA 15748 412-479-9382 or 479-9219 McCUNE LUMBER CO. 26 N. Fayette St. Shippensburg, PA 17257 717-532-4188 mmmmmmmmmmmmmmmM Ondulme The Lifetime Roofing Farm roofing that won't rust. rot, or corrode. New lifetime limited warranty*. 7 colors and 2 textures. Used in over 60 countries around the world. Now made in the U.S. ■ ■ No special tools needed * The terms of the lifetime limited warranty are avail able from any Onduline dealer. CLOE LUMBER & SUPPLY CO. INC. “Natural ventilation can be a money saver for your operation during much of the year,” Scar borough concludes, “but there’s no one set design for a building. You need an experienced and knowledgeable builder to get a properly operating unit.” pregnancy with at least 14 em bryos, we should be able to ap proach an average litter size of 14 live pigs,” Kephart says. “Currently the national average is about 10. So we have a long way to go. “To close that gap, we need a major effort from swine managers. We also need more research to answer some of the many questions which remain regarding the sow’s reproductive physiology. If we could reduce prenatal losses by half, we could add at least two pigs to every lit ter,” he says. “It’s certainly a goal worth working toward.” RD#6 Box 57 Punxsatawney, PA 15767 814-938-5220 SMICK LUMBER & BUILDING MATERIAL CENTER Box 127 Rt. 49 Quinton, NJ 08072 609-935-0500 E.W. BOSTWICK INC. Elmer & Center Sts. 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