DAIRY HERD HEALTHAnimal Science IUnit 44

Introduction

Subject to the same diseases and parasites as beef cattle

However, dairy cattle do have some health considerations that need to be emphasized

Herd Health Plan

Needs to be developed for maintaining the health of the dairy herd

Effective plans put emphasis on the prevention of problems

Vet services should be used on a regular and planned basis

A regular planned program of testing and vaccination should be carried out for the herd for Brucellosis Infectious Bovine Rhinotracheitis (IBR) Bovine Virus Diarrhea (BVD) Parainfluenza-3 (PI3)

Herd Health Plan

Keep health records Follow a parasite control program Follow a planned program for mastitis

control Keep accurate reproduction records Follow a planned calf health care plan

Management Practices to Reduce Herd Health Problems Proper feeding of the herd Good facilities with

ventilation Using dry, clean bedding Proper cleaning and

sanitation Controlling disease

carriers-flies, birds, rodents

Raising replacements needed for the herd

Requiring health records of replacement animals and isolating them for 30 days

Isolating sick animals Using a vet Controlling access to dairy

herds Require visitors to wear

protective footwear Do not allow visitors

unlimited access to where cattle are kept

Have bulk milk and feed delivery points as far away from cows as possible

Dairy Quality Assurance Program

Designed to help dairy farmers produce high quality milk

Participation is voluntary Developed by the National Milk Producers

Federation and the American Veterinary Medical Association

Producers are certified by going through a 10 point check list of management practices with a Veterinarian

Dairy Quality Assurance Program

Program identifies critical control points that help herd owners produce a high quality product

Emphasis is placed on following a preventative health program

Use of Drugs for Treatment of Dairy Cows and Calves

See p. 804 and 805 for the itemized list

Mastitis Control

Serious economic problem Causes losses by

Lowering milk production from infected cows Increasing the cull rate in the herd The cost of treatment Loss of infected milk that must be thrown away Increased labor cost to treat infected cows Possible loss of permit to sell milk if infection

becomes serious enough

Mastitis Control

Caused by bacteria that enter the udder through the teat opening

Bacteria may also enter through injury to the teat

May be acute or chronic

Acute Mastitis Symptoms

Inflamed udder Swollen, hot, hard, tender quarter Drop in milk production Abnormal milk

Lumpy, stringy, straw-colored, contains blood, yellow clots

Cow goes off feed, shows depression, dull eyes, rough hair, chills

Death may result

Chronic Mastitis Symptoms

Abnormal milk-clots, flakes, watery Slight swelling and hardness of udder

that comes and goes Sudden decrease in milk production

Chronic Mastitis

May not show any symptoms Often not treated Sometimes does not respond to

treatment More of an economic problem than the

acute form Both acute and chronic mastitis may

cause permanent udder damage

Leukocytes

White blood cells that fight infection Mastitis increases their presence

Somatic Cells and Somatic Cell Count and Mastitis Somatic cells are leukocytes and other

blood cells All normal milk contains some somatic

cells Goal of the dairy herd should be an

average of no more than 150,000-200,000 cells per milliliter

90% of the herd should be below 200,000 cells per milliliter

Somatic cell count can vary greatly from month to month in cows that have mastitis infection

Problem Somatic Cell Counts Daily per head losses increase as

somatic cell counts increase Ranging from 1.5 lbs at 72,000

cells/milliliter to 6.0 lbs at over 1 million cells/milliliter

Somatic cells counts over 500,000 usually indicated a bacteria infection, a cow in late lactation, udder injury or an old cow

Problem cows should be culled

Bulk Grade A Milk

Picked up at the farm it cannot have a somatic cell count exceeding 750,000 cells/milliliter

Violation results in the loss of the farms Grade A permit

Testing for High Somatic Cell Counts

Several test Most common is the California Mastitis

Test (CMT) Used to test the herd for mastitis and

should be used at least once a month

California Mastitis Test (CMT) A small paddle with 4 cups is used About 1 teaspoon of the first milk from

each quarter is placed in each cup, each quarter must be checked separately

A chemical that reacts with the milk is placed in each cup

The presence of leukocytes is shown by the reaction Slight precipitation show a low count A heavy gel and purple color show a high count

California Mastitis Test

http://www.youtube.com/watch?v=BvbZPk5riEc&feature=related

Other Methods of Testing

Lab Chemical Electronic

Controlling Mastitis

The following practices should be followed for an effective mastitis control program Maintain milking equipment in proper operating

condition Practice proper milking procedures Identify the bacteria causing the infection and

determine the extent of the infection in the herd

Promptly treat identified cases of mastitis Treat all quarters of cows when at drying off

time Cull cows with chronic mastitis problems that

do not respond treatment

Displaced Abomasums

Also called DA Condition where the abomasums moves out of

place in the abdominal cavity More common in dairy cattle than beef Majority of cases occur shortly after calving Symptoms

Poor appetite Reduced fecal discharge Soft or pasty feces Diarrhea Drop in milk production Dull, listless, thin appearance

Displaced Abomasums

Type of ration being fed appears to be involved

Too rapid an increase in grain feeding just before calving increases the chance of DA

Poor quality, moldy roughage or too much silage in the ration also increase DA

Do not over feed silage and concentrates to dry cows

Increase the amount of concentrate slowly at calving time

Retained Placenta

A condition in which the placenta is not discharged within 12-24 hours after calving

Normal for 10-12% of dairy cows A higher rate indicates a problem that

needs attention

Causes of Retained Placenta Infection in the reproductive tract during

pregnancy Deficiencies of vitamin A or E, iodine, and

selenium Calcium to phosphorus ratio in diet out of

balance Cow too fat Stress at calving Breeding a cow too soon after calving Good management is the best practice to

prevent retained placenta.

Ketosis

Nutritional disorder in dairy cattle Blood sugar drops to a low level Caused by not feeding enough high

energy feeds to meet the cows needs for high milk production

Usually occurs in the first 6-8 weeks after calving

Symptoms of Ketosis

Cows go off feed shortly after calving Drop in milk production Loss in body weight Cows become dull and listless Odor of acetone in breath, urine and milk

Preventing and Treating Ketosis Feed a properly balanced ration Common Treatments

Glucose injections into the bloodstream Hormone injections (cortisone or

adrenocorticotrophic hormone) Oral feeding of propylene glycol or sodium

propionate Feeding molasses will not cure Ketosis

Metritis

Infection of the uterus Affects cows within 1-10 days after

calving Higher rate is seen in cows that are too

fat at calving

Symptoms of Metritis

Loss of appetite Fever Drop in milk production Abnormal (thick, cloudy, grey, foul odor)

discharge from the vulva Standing with the back arched In severe cases, rapid death

Prevention and Treatment of Metritis

Feed a properly balanced ration to dry cows

Keep the calving area clean and sanitary Treat with intrauterine antibiotic drugs

Milk Fever

Parturient paresis Caused by a shortage of calcium salts in

the blood More common in older, high producing

cows Usually occurs within a few days after

calving

Symptoms of Milk Fever

Loss of appetite Reduction in quantity of feces passed In early stages excitement Staggering Depression Cold skin, dry muzzle Paralysis Lies on brisket with head turned back toward side Later stages, lies on side with head stretched out Bloating Death, if not treated

Prevention and Treatment of Milk Fever

Feed a balanced ration to dry cows with the correct calcium-phosphorus ratio

Treat by intravenous injection of calcium

Internal Parasites

Follow a regular program of treatment All mature dairy cows should be treated

for worms after each lactation Replacement heifers should be wormed

near the end of their pregnancy

External Parasites

Use care when using insecticides on the dairy

Use only insecticides approved for dairy animals and facilities

Follow label directions carefully to avoid illegal residues in the milk

Summary

Effective herd health plan emphasizes prevention

Good management helps prevent health problems

Mastitis is the most serious disease that affects dairy cattle

Use care when using drugs to avoid illegal residues in the milk

Good herd health plans increase net profits

Control internal and external parasites.

Assignment

Complete Unit 44 Review Questions—due Thursday Dec 2

Review for Test Dec 2 Test over units 39, 40 and 44 on Friday Dairy Anatomy Test December 8th