Skip Menu

Return to Skip Menu

Main Navigation

Return to Skip Menu

Main Content

Large Animal Clinical Sciences

Title Summary Date ID Author(s)
Bull Management for a Successful Breeding Season Jun 1, 2009
Club Lamb Fungus May 1, 2009 410-018
Dairy Heifer Health, Disease Control, and Vaccinations

The future of the dairy herd is dependent on the production of superior heifers to replace culled lactating animals. Therefore, it is imperative that the health status of the replacement animal is optimized to present a healthy first calf heifer to the lactating herd. Studies have consistently demonstrated the detrimental effects of pneumonia in calves on age at first calving and on milk production once these animals enter lactation. Calves with respiratory infections were twice as likely to leave the herd and age at first calving was delayed by 6 months when compared with calves that did not experience respiratory disease or pneumonia. In another study, calves treated for scours were three times more likely to calve at 30 months of age or greater.

May 1, 2009 404-284
Early Heifer Development and Colostrum Management

Raising dairy replacement heifers is expensive. In fact, if the dairy is divided into different enterprises (eg. labor, feed cost for lactating cows, facilities, etc.), rearing replacements is the second largest cost, behind feed cost for lactating cows. The percentage will vary from farm to farm, but approximately 9% to 20% of the expenses incurred will involve rearing and developing heifers. Therefore, heifers should represent a sound investment, as their impact on future herd profitability is enormous.

May 1, 2009 404-282
Goat-Herd Health Calendar

The goal of any goat-herd health program should be to increase efficiency and productivity. Herd health programs should include general husbandry, nutrition, and parasite and vaccination programs. Your emphasis should be on disease prevention rather than treatment. There are three major approaches for disease control:

  1. Keep resistance high.
  2. Avoid exposure.
  3. Recognize and address diseases early.
May 1, 2009 412-501
Health Care for Horses

Thoughtful and planned care will allow your horse to live a longer and healthier life. Good equine husbandry is based upon the principle of preventive care: problem prevention rather than problem treatment.

May 1, 2009 406-308
Heifer Inventory and the Economics of Replacement Rearing

Profitability in the dairy business is NOT the herd with the larger milk check, or the greater volume in the bulk tank, but the producer who retains a larger sum of revenues at the end of the month (income minus expenses equals profits). One of the larger expenses incurred on the dairy is replacement heifer rearing. Replacement rearing is second only to feed cost for the lactating cows. In surveys of dairy expenditures, this item accounts for 9 to 20% of the total expenses on the farm. In the authors' experience, producers are seldom aware of what heifers cost to raise, and most producers think that these expenses are negligible. Heifers are a high cost item when expenses are divided among the various enterprises on the farm.

May 1, 2009 404-287
Intensive Marine Finfish Larviculture

Marine finfish production is a rapidly expanding field, both in research and industrial aquaculture. A driving force behind this growth is the inherently high value placed upon marine finfish products in the marketplace. 

May 1, 2009 600-050
Livestock Update - June 2009 Jun 1, 2009
Livestock Update - May 2009 May 1, 2009
Milk Production Evaluation In First Lactation Heifers

A critical evaluation of production in first lactation heifers once they reach the milking herd is important to determine the effects of the heifer rearing program. This can easily be done by monitoring start-up milk (milk production 0 to 40 days in milk), start-up milk butterfat and protein, and peak milk, peak milk butterfat and protein (41 to 100 days in milk) because these are directly related to heifer development.

May 1, 2009 404-285
Monitoring Dairy Heifer Growth

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.

May 1, 2009 404-286
Mycoplasma in Dairy Cattle

Mycoplasma is a tiny bacterium that can cause mastitis, metritis, pneumonia, drooped ears, and lameness in dairy cattle. While this bacterium has existed for more than 100 years, the current disease was first recognized in the 1960s and 1970s, and has only recently become a problem in Virginia. There has been a steady rise in the frequency and severity of disease associated with Mycoplasma in the last ten years. Mycoplasma is a highly contagious disease that can have devastating economic effects on a dairy farm due to decreased milk production, additional veterinary costs, culling of cows, calf loss, and treatment cost. All dairy animals can be infected, including calves, heifers, dry cows and lactating cows.

May 1, 2009 404-038
Nutrition For The Early Developing Heifer

Several factors can dramatically reduce replacement-rearing cost and increase potential profits for the producer: (1) maximizing immunity from colostrum to minimize mortality and sickness, (2) formulating rations for specific weight gains during strategic periods of development and avoiding over-fattening prior to puberty because it impairs mammary development, (3) formulating rations for an average daily gain of 1.8 lb. for Holstein heifers, (4) using AI sires ranking in the top 20% for (PTA$) to optimize genetic improvement, (5) monitoring age, body weight, wither height, body condition score as well as peak milk and ME milk yield of first lactation heifers to evaluate management at first calving, and (5) controlling the size of the replacement herd by calving heifers at 24 months and raising no more than needed.

May 1, 2009 404-283
Predicting Bull Fertility

Reproductive efficiency is a major determinant of cow-calf profitability. The bull’s contribution to pregnancy rates is often overlooked.

May 1, 2009 400-009
Summer Fly Control on Cattle Jul 10, 2009
Understanding the Basics of Mastitis
Mastitis occurs when the udder becomes inflammed because leukocytes are released into the mammary gland in response to invasion of the teat canal, usually by bacteria. These bacteria multiply and produce toxins that cause injury to milk secreting tissue and various ducts throughout the mammary gland. Elevated leukocytes, or somatic cells, cause a reduction in milk production and alter milk composition. These changes in turn adversely affect quality and quantity of dairy products.
May 1, 2009 404-233
What to Do When Cows Die May 1, 2009
Youth Cattle Working Contest: Intense Competition and Great Learning May 5, 2009