Dairy Cattle -Reproduction, Genetics, & Health

Pasteurization

Controlled heating of a product to destroy microorganisms

Babcock Cream Test

Introduced in 1890; determines the fat content of milk (Highest milk fat percentage: Hooded Seal w/ 60%, Lowest milk fat percentage: Black Rhinoceros w/ 0/2%)

California milk and cheese seals

"Real California Cheese" (1984) and "Real California Milk" (2007)

State with the most dairy cattle in the US

California

City that once held the most dairy cattle

Chino (400+ dairies, 400,000+ cows)

Where over 50% of California dairies are located (2005)

Merced, Madera, Fresno, Kings, Tulare, and Kern counties

Holestein

Black & white, large, from the Netherlands, most popular US breed; milk fat 3.7%

Red and White

Red & white "red Holstein," from the Netherlands, large; milk fat 3.7%

Ayrshire

Red & white, from Scotland, moderate size; milk fat 3.9%

Milking Shorthorn

Red, white, or roan, from England, large, docile; milk fat 3.6%

Brown Swiss

Brown, black, grey, or white, from Switzerland, moderate size, docile, long-lived; milk fat 4.1%

Guernsey

Tan or brown, from the Isle of Guernsey, smaller, calm, hardy; milk fat 4.6%

Jersey

Tan to brown, from the Isle of Jersey, small; milk fat 4.8%

Marsupials

can control what goes into their milk based on offspring age

Dry Cow

female dairy cow that has previously lactated but who is not currently producing milk

Dry Period

when a lactating dairy cow stops getting milked and is allowed about 60

days to gain back weight that may have been lost during lactation (2 months prior to calving)

Fresh Cow

a dairy cow that has recently calved

Weaning

the process of transitioning a calf away from a diet containing milk or milk

replacers to an all-solid feed diet or ration

Withdrawal Period

the period that is required to elapse following the administration of an approved animal drug before the milk can be sold for human consumption and/or the animal can be harvested for meat.

Dry Cow Treatment

an intramammary antibiotic that is administered into each teat at the beginning of the dry period to prevent and/or treat udder infections

Lactating Cow Treatment

an intramammary antibiotic that is designed for use during the normal lactation period.

Teat Sealant

 a paste that is infused into the end of each teat following dry cow treatment to prevent introduction of infectious agents

Voluntary Waiting Period

a two to three month period following calving before the cow is rebred by AI or allowed exposure to a bull allowing for the cow’s reproductive system to recover

Sterility

Reproductive failure is the permanent or temporary sterility (inability to reproduce) of an animal

Five main categories of causes of reproductive failure

physical defects, diseases, environmental factors, and nutritional factors. Freemartinism is a specific physical-defect example in females

Physical defects that cause reproductive failure in males

Cryptorchidism, malformed penis, or scrotal hernia

Physical defects that cause reproductive failure in females

Absence of ovaries or hormonal imbalance

Freemartinism

the female twin of a male calf whose reproductive tract is incompletely developed

Two diseases are named as infectious causes of reproductive failure in cattle

Infectious Bovine Rhinotracheitis (IBR) and Bovine Viral Diarrhea (BVD)

Environmental factors that cause reproductive failure

Physical damage to reproductive organs or stress

Nutritional factors that cause reproductive failure

Nutritional deficiencies, obesity, or ingestion of toxic plants

Veal

meat from a calf or young beef animal

‘Bob’ Veal

veal calves that are up to 3 weeks of age or 150 pounds (about 15% of veal production)

‘Special-Fed Veal

milk and formula fed veal calves raised until 5 months of age or 500 pounds (majority of veal production)

Grain-Fed Veal

veal calves fed grain, hay, or other solid food in addition to milk

Rose Veal (Pasture-Raised Veal)

 veal calves raised on open pasture where they are provided grass and milk until 6 months of age or 550 pounds

Mastitis

Inflammation of the udder

Causes: Bacterial infection or other infectious organisms that enter the udder from the outside environment

Symptoms: Decreased milk quality and production, swelling, redness

Treatment: NSAIDs (nonsteroidal anti-inflammatories), aspirin or ibuprofen

Prevention: Clean environment, udder disinfection and hygiene, regular testing and maintenance of milking machines

Milk Fever (Hypocalcemia)

Sudden loss of calcium when milk production begins, because the mineral is sent to the milk. This disrupts nerve and muscle function.

Symptoms: Restlessness, muscle tremors, unable to stand

Treatment: Intravenous calcium supplementation

Prevention: Nutritional supplementation of calcium during late pregnancy

Displaced Abomasum

Excess gas makes the abomasum (the true stomach) rise to the top of the abdomen

Symptoms: Loss of appetite, reduced rumination, abdominal pain, bloating

Treatment: Surgical correction (or rolling the cow in mild cases)

Prevention: Slowly introduce high-grain diets, provide adequate roughage, manage weight at calving, minimize stress

Johne’s Disease

Contagious intestinal infection from a bacterium embedded in the wall of the ileum of the small intestine

Transmission: Oral ingestion, contact with infected feces or saliva, passed from mother in the uterus, infected milk

Symptoms: Chronic diarrhea, weight loss, bottle jaw

Treatment: No effective treatment

Prevention: Prevent contact with infection, vaccination, testing to aid detection, sanitation

Hardware Disease (Traumatic Gastritis)

Ingested metal pierces the wall of the reticulum, causing infection and/or damage to the stomach and other organs

Symptoms: Loss of appetite, arched back, stiffness in moving, bloating

Treatment: Surgery to remove the metal, plus antibiotics

Prevention: No metal in feed, keep pastures clear of metal, and ingestion of a magnet