The Many Faces Of BVD (Continued from Page 31) tissues can cause many types of birth defects. Some of these calves infected later in gestation will be born small and Weak, at term or prematurely. The BVD virus can interfere with reproduction even before conception. The BVD virus has two known ef fects on the cow’s ovaries. The infected ovaries pro duce eggs of poor quality and cause the ovary to produce less progesterone than may be necessary to maintain a pregnancy. These cows return to heat, sometimes after missing several heats. One PI in a herd can continue to expose cows to the virus, causing real disruption of a breeding program. Eliminating And Avoiding BVD Problems So how can all these problems be avoided? A three-pronged effort is required. Step one involves increasing herd resistance to BVD by a good vaccina tion program. This should include use of a modified live vaccine in young stock at four to six months of age and a booster with the same type of vaccine pre-breeding. Annual or semiannual booster vaccination of cows needs to be continued in the herd with a vaccine approved by your veterinarian for your herd. 701 E. Linden St. Richland, PA 17087 717-866-6581 MEMBER MEMBER TRUSS PLATE INSTITUTE 701 E. Linden St., Richland, PA 17087 MANUFACTURERS OF: Glu-Lam Arches Roof Trusses Clu-Lam Beams Floor Trusses Glu-Lam Treated Posts T/G & V-Groove Decking Equis Quality Stall Systems Door and Wall Systems Crillwork Sections Dutch Door Systems Plyco Doors and Windows Over 40 Tears of Quality Service Step two will involve removing any persistently in fected animals from the herd. Culturing bulk tank milk samples can determine if there are any PI cows. These tests are very sensitive, detecting one positive cow in a group of up to several hundred. If the bulk tank test comes back positive, follow up testing will need to be completed on smaller groups and eventually on individual cows. Calves can be tested by submitting a small piece of skin such as a notch from an ear for virus detection. This is a fairly new test, but very sensitive and can be done on calves of any age. This makes it possible to identify those carrier calves at an early age and get them out of the herd. The third prong of the strategy involved not buying more BVD infected stock. Test all new stock before adding to the herd and make sure they were properly vaccinated as young stock. Isolate new purchases in a separate facility from farm stock and be sure new stock tests negative before adding to the herd. BVD can be a real disaster in a herd. But it is possi ble to get this disease out of a herd and prevent it. I continue to be surprised by the number of herds which do not vaccinate, at least not properly, for this disease. WE STOCK: Cannonball Track and Accessories Fabral Roofing and Siding Lumber and Shingles All Types of Fasteners (Turn to Page 33) 1283 Joni Miller Rd. Oakland, MD 21550 301-334-3977 Active Member
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