Ch.1.5 Stress at WeaningCh.1.6 Milking PracticesCh.1.7 Dairy Herd Health

MSc. Mohammed Sabah

Ch1. Dairy cows management

Ch.1.5 Stress at Weaning

Introduction.

Many dairy producers report that calves often have a very difficult time right after weaning. Calves may slow down in growth and intake. Often they're more susceptible to infections - especially respiratory infections. As a result, calves often experience "weaning slump", and it make take several weeks for them to get out of their slump. This reduced intake and growth associated with weaning is common in dairy calves and is usually associated with weaning, the increasing reliance on dry feed intake and ruminal fermentation, and changes in housing that often accompany weaning.

The key management strategy needed to reduce weaning slump is to minimize stress. Often, calves are weaned, moved from individual housing into group pens of 4 to 20 calves, fed a different ration, and exposed to lots of new pathogens in their new environment. This type of weaning management is a sure recipe for setting calves back for several weeks while they try to adjust to all the stresses imposed at this time.

Here are some tips to help your calves ease the transition through weaning:

1- Wean your calves when they have eaten sufficient dry feed (especially calf starter) to develop their digestive systems - particularly the rumen. This point is reached when calves are eating at least 1.5 to 2.0 lb (680 to 907 grams) daily for two consecutive days.

2- If you wean calves according to age (usually 6 to 8 weeks of age), keep an eye on intake, too.Remember, rumen development and a calf's ability to digest dry feed is not solely a function of age. Rumen development occurs as calves begin to consume dry feed - particularly calf starter. While most calves begin consuming starter at 1 to 2 weeks of age, some calves -those that are sick or weak - may not start eating starter for several weeks.

3- Make sure there's plenty of fresh, clean water available at all times. As dry feed intake increases, calves will consume more water.

4- Additives in starter may help to stabilize ruminal fermentation. These include sodium bicarbonate (stabilize rumen pH, reduce lactate production), and yeast culture (reduce amount of lactate in the rumen) have shown to affect rumen fermentation and improve intake of starter by calves.

5- Some producers use antibiotics added to the feed to reduce the risk of respiratory disease.

And here are a few tips related to moving calves from individual pens into groups:

1- Don't move calves at the same time you wean them. Allow a week or two for the calf to adjust to the stress of weaning before introducing the stress of moving.

2- Provide good ventilation to calves when they are moved into groups. Stress and poor ventilation are the major factors responsible for increased disease incidence shortly after weaning.

3- Provide a coccidiostat in the starter/grower fed to calves after weaning. As calves are moved from individual housing to pens, they are often exposed to a wider array of pathogens. Coccidiosis is particularly common in calves from 4 weeks of age and later.

4- Don't wean or move calves during times of weather extremes or changes unless absolutely necessary. Weather is a source of stress for calves - our goal during the weaning period is to minimize the many stresses we impose on an animal.

5- Keep the number of newly weaned calves in a pen to 4 to 6. This is a large enough group for you to manage, but small enough for the calves to adapt to the new surroundings.

Ch.6Recommended Milking Practices

Recommended Milking Practices

• Follow a regular routine• Prepare the cow for milking by washing the

udder• Use a strip cup to stimulate milk let down and

remove the first milk which is high in bacteria count

• Attach the milking machine within 1 minute of stimulating milk let down

• Remove the milking machine gently to prevent disease and damaging the udder

• Dip the teats after milking with a teat dip• Wash your hands• Do not try to operate two many units---

this can cause udder damage due to over milking

• Milk in order– Heifers, cows in early lactation and normal

cows first.– Cows with udder infections should be milked

last.

Milking Barn Safety (Dairy Safety Training Part I, Section 2) - YouTube

The risks relating to poor hygiene associated with such a procedure include:

1- Poor milk quality

2- Mastitis cross contamination

3- Spread of pathogens

4- Poor stimulation

5- Long waiting time

6- Poor working conditions

Milking Procedures for Maximum Milk Quality - YouTube

Ch.1.7 Dairy Herd Health

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

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 cellsAll normal milk contains some somatic cellsGoal of the dairy herd should be an average of no

more than 150,000-200,000 cells per milliliter90% of the herd should be below 200,000 cells per

milliliterSomatic 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