Dairy Cattle

ANS 150

US Dairy Demographics

• # of farms decreased

• # of cows, pretty much the same

• Income Increased

reason: less family owned small dairy farms, more larger commercial farms

NC Market Share

Operations: Decreased

Inventory: Same

Income: Same

Reason: Same as the US

What region of NC has the most dairy operations?

Piedmont and mountain regions

Where are the dairy operations usually located around in NC?

around major/large cities/popuations

1990’s gov buy out program

• gov paid dairy farmers to STOP producing milk

• was created to try and help the over supply of demand of milk

• approximately 1/5 of N.C. dairy producers decided to stop production.

Urban Sprawl

as the value of dairy farmer’s land increases find it harder to justify continued production

Why is most milk production in the US located around major cities?

•  Consumers want fresh products and milk has a short shelf life •

• Therefore, most of major dairy production is located near major population centers

• they are also located in colder states

Estrus Cycle

• in heat for 12-18 hours

• ovulate after they go out of heat

• Lactation for 305 day

• Wean calves at birth or shortly after

• gestation 284 days

• MUST wait 60-90 days to rebreed

Difference in production calendar between dairy and beef cattle

• in dairy calves are weaned at birth or shortly after

• lactation is prolonged

When do heifers breed

• exhibit several estrus before bred

• bred at 2 years old

(both the same as beef cattle)

Why Artificial Insemination?

• Milk production is a highly inheritable trait (easy to select for and make genetic improvement)

• Dairy Cows are intensively managed (not a lot more labor to “round them up” unlike beef0

• Dairy bulls are MEAN

• they can also “sex the semen” meaning that they can almost guaruntee a male or female will be born

Lactation curve

• increases from day 0-50

• from days 50-100 milk production is peak

• then slowly decreases from then on

Differences in Lactation curves

usually due more to an extension of peak production (65%) rather than an increase in the amount during peak production (35%)

How are dairy cows managed (milk production wise) throughout the year.

• they are managed in groups so there is always a group with peak lactation throughout the year

free stall

• since lactation is intensively managed, cows are usually given supplemental grain through free stalls

Concentrate

mixture of silage and corn, cottonseed hulls or other high energy feeds.

Why roughage (fiber)intake is important in dairy cows

• several metabolic problems can occur.

• percentage of milk fat is decreased which makes milk of lower quality for resale

Mechanical Milking

• oscillations between positive and negative pressure

• Milking system must be checked and adjusted on a regular basis so they are not over milked

Antibiotics in Milk

• zero tolerance

• A sample of milk is taken from the bulk storage tank at each farm and tested for antibiotics. 

• If it comes back positive, then the milk isn’t purchased or unloaded into the tanker truck.

• Antibiotics are an approved way to treat cows with problems that occur normally and are approved by the F.D.A. and have specific withdrawal times

Genetic selection

• Dairy industry has made the best use of genetic selection for improved productivity than any other commodity except the poultry industry

• This is partially due to the fact that milk production has a high heritability

Weaning

• Calves are weaned at birth or shortly after (24 to 48 hours)

• Kept in ‘calf hutches’ until about 7 weeks of age

• Fed 1 to 2 gallons of milk per day and a calf “concentrate” free choice

• Separation from other calves and cows (biosecurity)

• Colostrum first 24-48 hours of life (passive immunity)

Weaning dairy calves 7-9 weeks

• Dairy calves are kept in calf hutches until they are 7 to 9 weeks of age.

• They should be fully transitioned onto a roughage, concentrate diet with no milk by this time (weaned for a second time).

Weaning dairy calves 9 weeks

• they are regrouped and placed on pasture.

• They are fed in a similar fashion to adult, lactating cows – access to pasture / hay all the time and fed a concentrate (silage mixture) twice per day