Browsing by Author "Murphy, Julia M."
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- Comparison of Neospora seroprevalence in Virginia dairy herds with high and low abortion ratesMurphy, Julia M. (Virginia Tech, 1998-06-30)Neospora has become a commonly recognized infectious cause of abortion in dairy cattle. The organism is associated with mid to late term abortion outbreaks with rates exceeding 30% in some herds. Cows infected with this organism exhibit no other clinical signs. While this disease has been reported in other parts of the country, no assessment of Neospora seroprevalence has been undertaken in the Southeast. This study sampled commercial dairy herds to assess Neospora seroprevalence in dairy cows and investigate its significance as an abortifacient agent in Virginia. Twenty four herds participated in the study. Twelve herds had DHIA reported annual abortion rates of 6% or greater (high abortion rate herds) and twelve herds had abortion rates of 2% or less (low abortion rate herds). High abortion rate herds were each paired to a low abortion rate herd (control) herd within the same county. A single blood sample was collected from all cows confirmed to be 90 to 240 days pregnant, with a maximum of thirty samples per herd. A random sample of cows was selected in herds with more than 30 pregnant cows between 90 and 240 days gestation. Neospora antibody titers were determined using a serum ELISA test at the California Veterinary Diagnostic Laboratory. Both mean and median seroprevalence of high and low abortion rate herds were compared using the Mann-Whitney Rank Sum test and the Median test, respectively. No significant difference was found in either case (p=0.56, p=0.41). These findings suggest that Neospora does not contribute significantly to the average abortion rate in Virginia's dairy cattle.
- Dairy Heifer Health, Disease Control, and VaccinationsBailey, Thomas L.; Murphy, Julia M.; James, Robert E. (Virginia Cooperative Extension, 2009-05-01)The future of the dairy herd is dependent on the production of superior heifers to replace culled lactating animals. It is imperative that the health status of the replacement animal is optimized.
- Early Heifer Development and Colostrum ManagementBailey, Thomas L.; Murphy, Julia M.; James, Robert E. (Virginia Cooperative Extension, 2009-05-01)Approximately 9% to 20% of the expenses in- incurred on dairy operations will involve rearing and developing heifers. Therefore, heifers should represent a sound investment, as their impact on future herd profitability is enormous.
- Early heifer development and colostrum managementBailey, Thomas L.; Murphy, Julia M.; James, Robert E. (Virginia Cooperative Extension, 1999)Raising dairy replacement heifers should represent a sound investment, as their impact on future herd profitability is enormous.
- Monitoring Dairy Heifer GrowthBailey, Thomas L.; Murphy, Julia M. (Virginia Cooperative Extension, 2009-05-01)Monitoring dairy heifer growth and development will insure that calves are on target to reach a weight of 1350 pounds at calving, with a height of 54 inches at the shoulders, and a body condition score of 3.25 to a 3.5 at 24 months of age
- Monitoring dairy heifer growthBailey, Thomas L.; Murphy, Julia M. (Virginia Cooperative Extension, 1999)Monitoring dairy heifer growth and development will insure that calves are on target to reach a weight of 1350 pounds at calving, with a height of 54 inches at the shoulders, and a body condition score of 3.25 to a 3.5 (5 Point scale) at 24 months of age (Figure 1 ). Heifers should start lactation with a post-calving weight between 1225 and 1250 pounds; therefore, they will need to add 50 pounds of body weight per month from birth to first calving for an average daily gain of 1.8 pounds per day. Average daily gains of 1.3 pounds per day are too low because they add only 40 pounds per month, resulting in a post-calving weight of 950 pounds. By strategically feeding during specific growth phases, producers can set goals for different months of age, cut expenses, and increase profits for the dairy...
- Nutrition for the early developing heiferBailey, Thomas L.; Murphy, Julia M.; James, Robert E. (Virginia Cooperative Extension, 1999)Discusses nutrition for heifers and presents several factors that can reduce replacement-rearing costs and increase profits for the producer.
- Nutrition For The Early Developing HeiferBailey, Thomas L.; Murphy, Julia M.; James, Robert E. (Virginia Cooperative Extension, 2009-05-01)Discusses nutritional factors for developing heifers and reducing replacement rearing costs, while increasing potential profits for the producer.