Lecture 1: Miles stones for Dairy Cow

Terminology Review

Define each of these terms:

-calf

-Heifer

-Weaning

-Bull

-Cow

-Dry/Dried off

-Parturition/Freshening/Calving

-Transition Phase

-Age at first calving

-peak

-Persistency

-First calf heifer-misnomer

State length of time

-gestation

-pre weaning

-age at first calving

-puberty

-Dry period

-calf: new born

-Heifer: young female cow that has not borne a calf

-Weaning: removal of milk from calf’s diet(transition phase)

-Bull: intact adult male(used for breeding)

-Cow: has had offspring

-Dry/Dried off: stop milking to allow mammary gland to rest and regenerate for next lactation

-Parturition/Freshening/Calving: birthing

-Transition Phase: 4 weeks before calving and 4 weeks after calving where critical change in energy demand, immune function, cows are more susceptible to disease

-Age at first calving: 24 months

-peak: peak lactation period

-Persistency: slope of lactation curve after they peak

-First calf heifer-misnomer: commonly used in industry

State length of time

-gestation: 280 days

-pre weaning: 8-9wks

-age at first calving: 24 months

-puberty : 9 months

-Dry period: 60 days

Concept: Milestones for a Dairy Animal

1. 1. Newborn Calf

2. - what must be feed and how much should be feed after birth?

3. -what are alternatives?

4. -when and why are grains introduced into the diet?

1. 1. Newborn Calf

2. -calves must be feed colostrum, should be able 10% of body weight, provide immunity as placenta does not allow for transfer of antibodies

3. -fed milk or milk replacer for about 2 months

4. -grains are introduced within 1st week to help develop the rumen

Concept: Milestones for a Dairy Animal

2.Weaned

-what is weaning

-what age does this occur

-what is the goal of weaning

-how much grain would they be consuming and for how long?

-no longer feed milk and transitioned to all calf grain + water

-occurs 8-9wks of age

-goal is to double birthweight

-consume at least 2+ lbs of grain(starter) for 3 days straight

Concept: Milestones for a Dairy Animal

3.1st Breeding

-what age should this occur and approximate what body weight?

-what are ideal growth rates?

-what are repro goals for conception and heifer pregnancy rate

-should be 12-13 months + 55% of mature body weight

-should be gaining about 2lbs per day

-Repro: 1st conception rate(70%), Pregnancy rate (47%) *how much of the herd was actually successful

Concept: Milestones for a Dairy Animal

4. 4.Gestation

5. -how long is this period?

6. -how does stress impact length?

7. -what ideal body weight for 1st time calvers?

~280 days

-stress can lead to shorter gestation period

-seasons can cause slightly longer or shorter periods, so can male calves and twins

-85% of mature BW, retained for herd

What occurs to Dairy Bull Calves?

Bob Veal Calves (harvested ~3 weeks of age)
• Veal Calves (harvested 16-20 weeks of age)
• Dairy Beef (harvested 12-15 months of age)
• Used for Breeding Stock (on farm or housed at
semen collection facility; very small percentage
of bulls)d ~3 weeks of age)
• Veal Calves (harvested 16-20 weeks of age)
• Dairy Beef (harvested 12-15 months of age)
• Used for Breeding Stock (on farm or housed at
semen collection facility; very small percentage
of bulls)

Analyzing Lactation

What is the main difference between 1st and 2nd lactation Curve?

-1st lactation has a lower peak but is more persistent

-2nd lactation has a higher peak but is less persistent

5.Breeding after 1st lactation

-how long is the estrus cycle

• -21 days

• -conception rate: ~ 42-45%

• -pregnacy rate: x>25%

6.Dry Off

-what is the purpose of this?

-length of time?

-what is administered into the teat?

-allow mammary gland time to rest and regenerate for next lactation

-50-60 days before next calving

-inject antibiotics into mammary gland to prevent infections

Overview of Cycle

review