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Tufts OpenCourseware
Author: One Health Students

Fall 2008
Gretchen Kaufman, DVM
Cummings School of Veterinary Medicine at Tufts University

1. Concepts – Student Work

Types of farming considered in this seminar



63 cows

67 cows

400 acres

400 acres

200 acres cropland

290 acres cropland

130 acres pasture

38 acres pasture

3,455 lbs milk/cow (annual)

19,457 lbs milk/cow (annual)

Holstein cross-breeds


>50% pasture May-Oct

<25% pasture fed

supplemental feed purchased

total mixed ration

crop rotation




conservation tillage




individual/family ownership

individual-family ownership

tie-stall barn

tie-stall barn

pipeline milking

pipeline milking

calf hutches

calf hutches

homeopathy, nutrition


What is Herd Health Management?

In any livestock production system, certain diseases and production constraints can be anticipated on the basis of accumulated experiences. Herd Health management and preventive medicine programs are designed to minimize potential adverse effects of these predictable constraints and to protect against unexpected ones. The goal of the program is to improve the herd's productivity through general husbandry, nutritional management, parasite control, vaccination, and environmental management.

Many herd health programs fail in their objectives because too much reliance is put on vaccinations and other treatments. A comprehensive herd health program recognizes vaccination as an important tool, but not a cure all. Effective programs integrate medicine and management to prevent disease. Three major factors should be considered in attempting to keep disease losses to a minimum:

  1. Prevent Exposure to Disease. Purchase and quarantine procedures should be employed to decrease the likelihood of disease introduction into the existing herd. In high intensity operations, increasing confinement means increasing exposure to disease-causing organisms that exist in all groups of animals. Such operations need more intensive preventive programs.

  2. Keep Disease Resistance High. Nutrition, management, and housing programs should be designed to keep resistance to disease high at all times. Preventing or minimizing animal stress is a necessity for maintaining good resistance. In addition to these measures, resistance to specific diseases can sometimes be accomplished by vaccination.

  3. If Disease Occurs, Prevent its Spread. Segregate affected animals immediately. Have a diagnosis made, and take recommended action as soon as possible.

Dairy Herd Health

  • Well recognized measures of individual animal and herd health exist (see PowerPoint and references)

  • Measures provide an objective way to compare organic and conventional herds

Wildlife Health

  • Diseases may spread from wildlife to cattle and from cattle to wildlife

  • Wildlife affected by farm land use

  • Little information on effects of organic vs conventional farming on wildlife

Domesticated Animal Health

  • Pets and other livestock on farms may interact with dairy herd

  • Potential for disease spread among these groups

  • Little information for effects of organic vs conventional farming on these groups of animals

Herd Health indicators

  • Mastitis: BTSCC, CMT

  • Reproductive diseases: abortion, infertility, metritis

  • Lameness

  • Calf health

  • Internal parasites

  • Animal welfare: management, comfort, hygiene

Indicators of Environmental Health

The primary concept around measuring health is using measurements, both subjective and objective, as indicators. Assuming that a measurement is both accurate and reliable it can be used to indicate level of health. The use of indicators to assess health requires that there is an established link between a condition (health level) and the indicator. Indicators of environmental health can be taken from a wide spectrum and be highly variable. We have chosen to divide indicators into three general categories:

  • Ecological Criteria

    • Biodiversity

    • Population size

    • Health of living organisms

    • Sentinel species

    • Presence of pathogenic organisms

  • Chemical Criteria

    • Nutrient and mineral content of environmental media

    • Presence of toxic compounds

  • Physical Criteria

    • Soil quality

    • Surface water turbidity

    • Surface water dissolved oxygen

    • Odor

    • Ability of environmental cycles to function