Lecture 18 and 19: Dairy production

Key performance indications for cows?

• Weekly hard count of new pregnant cows

• Palpation pregnacancy rate (>60% in cows)

• # of cows leaving the herd w/in the first 60 days in milk

• Butterfat % for the first 30 DIM

• Week four milk weights (not done in every herd)

Determined by herd owner. Fixed period following calving before attempting to breed cows. Often the same from cows in the herd although some have a longer VWP for 1st lactation animals. Usually between 40-70 days

Voluntary Waiting Period (VWP)

What 2 factors seem to play a role in cow’s calving interval?

• High producers tend to have silent heat more often than low producers

• Dairy farmers may give high producers a long wait period being bred back

Breed at first estrus 60 days postpartum, 13-month calving interval may be optimal

High-producing cows

Breed at first estrus 40 days postpartum, 12-month calving interval may be optimal

Medium/low producing cows

21-day pregnancy rate by date, sometimes called pregnancy risk

Bredsum

• Number of days between calving and when the animal is bred for the first time

• Calculated on a herd basis- not for an individual animal

• Animal may or may not conceive to this breeding/service

Days to first service (VWP +18)

• Number of days between calving and conception

• Calculated on a herd basis- not for an individual animal

Days open (DO)

• Period from one calving until the next

• Measured in months

• Calculated on a herd basis

Calving interval

Calving interval (CI) equation

(Days open + Gestation period)/ (Average 30 days in a month)

Service/conception equation

(# of services)/ (# of pregnant cows)

Services per conception is an inversion of ____ rate

Conception rate

Conception rate equation

(# pregnant cows)/ (# of services)

Aka submission or service rate. Percentages of eligible cows detected in heat during a 21-day period. Cow % that receive at least one insemination during the 21-day period

Heat detection (>70%)

How can you calculate pregnancy rate?

PR= (# of cows pregnant)/ (# of opportunities to get cows pregnant)

OR

PR= conception rate x service rate

What are the major areas affecting reproductive performance?

Cow, semen, environment, labor, nutrtion

Ideal BCS for fresh cows?

3.25-3.75

What is the ideal stocking rate?

80%

Ideal percentages of post partum diseases?

• metritis- <10%

• Retained placenta- <5%

• Ketosis- <5%

• DA- <5%

When should you minimize pen movements?

10 days before calving

How much bunk space is needed for pre-fresh and fresh cows?

~30” per head

What system can be used for breeding?

• Visual observation

• Walk and chalk

• Times AI

• Activity detection system

• Natural service (Fallen out of favor)

What the thaw temp and time for semen?

95F for 45 seconds

Where do you inseminate the cow?

¼” past the cervix of the uterine body, DO NOT PLACE in a single horn

What needle is used for hormone injections?

18g 1 1/2” needle

How many hours should a cow devote to eating?

3-5 hours

How many hours should a cow devote to resting?

12-14 daily

How many hours should a cow devote to standing/walking?

2-3 hours

How many hours should a cow devote to drinking?

30 minutes

Allow __ ft of space per cow

100 ft

What is the best stocking rate density for pre-freshing pens?

<80%

Common symptoms of acidosis?

• Low milk fat test- <3

• Score hooves- laminitis

• Cycling feed intake

• Diarrhea

• Liver abscesses

• Low rumen pH (<5.8)

• Limited cud chewing

Common symptoms of ketosis?

• Excess ketone bodies in blood and urine

• Lack of appetite

• Lethargy or excitability

• WL

• Decreased milk production

• BCS >4.0

What 6 mycotoxins can affect dairy herd fertility?

Aflatoxin, Zearalenone, Deoxynivalenol (DON), Ergotamine, Orcatoxin, Toxin T2

Which of the following is NOT explicitly listed as a common problem area that impacts dairy reproduction? a) Cow Comfort b) Nutrition c) Genetics d) Protocols/Processes

c) Genetics

What is the primary purpose of benchmarks in dairy herd management? a) To set goals for future production. b) To provide standards for measuring and comparing performance. c) To dictate specific management practices. d) To guarantee future success.

b) To provide standards for measuring and comparing performance

A weekly hard count of new pregnant cows should ideally be what percentage of the milking herd, according to one source? a) 5-7% b) 8-10% c) 12-14% d) 15-17%

b) 8-10%

What does VWP stand for in the context of dairy reproduction? a) Voluntary Weight Period b) Variable Waiting Period c) Voluntary Waiting Period d) Veterinary Withdrawal Period

c) Voluntary Waiting Period

The Voluntary Waiting Period (VWP) is determined by: a) The veterinarian. b) The herd owner. c) Industry standards. d) The cow's lactation number.

b) The herd owner.

What is the typical range for the Voluntary Waiting Period (VWP) in days? a) 10-30 b) 30-40 c) 40-70 d) 70-90

c) 40-70

Days to first service is calculated as: a) Days Open + Gestation period b) Calving Interval - Gestation period c) VWP + 18 d) Days Open - VWP

c) VWP + 18

Days Open (DO) is defined as the number of days between: a) First service and conception. b) Calving and conception. c) Calving and first service. d) One calving and the next.

b) Calving and conception.

What is the formula for calculating Conception Rate (CR)? a) Total number of services / Total number of pregnant cows b) Total number of pregnant cows / Total number of services c) Total number of cows pregnant / Total number of opportunities to get cows pregnant d) Conception rate x service rate

b) Total number of pregnant cows / Total number of services

Heat detection rate is also known as: a) Conception rate. b) Pregnancy rate. c) Submission rate. d) Calving interval.

c) Submission rate.

Pregnancy Rate (PR) can be calculated as: a) Conception rate + service rate. b) Service rate / conception rate. c) Conception rate x service rate. d) Total number of services / Total number of pregnant cows.

c) Conception rate x service rate.

What is a recommended Body Condition Score (BCS) for fresh cows? a) 2.5-3.0 b) 3.0-3.25 c) 3.25-3.75 d) 4.0-4.5

c) 3.25-3.75

What is a recommended maximum percentage for Metritis in fresh cows? a) <5% b) <10% c) <15% d) <20%

b) <10%

What is a recommended minimum bunk space per head for both pre-fresh and fresh cow pens? a) 18 inches b) 24 inches c) 30 inches d) 36 inches

c) 30 inches

Where should semen ideally be placed during artificial insemination? a) In a single uterine horn. b) At the external cervical os. c) ¼” past the cervix in the uterine body. d) In the vagina.

c) ¼” past the cervix in the uterine body.

Maintaining what temperature is important for semen handling from thaw to insemination? a) 85 F b) 95 F c) 100 F d) 105 F

b) 95 F

Approximately how many hours per day do dairy cows typically spend lying down (resting)? a) 8-10 hours b) 12-14 hours c) 16-18 hours d) 4-6 hours

b) 12-14 hours

What is the recommended space per cow to avoid reducing resting time due to stocking density? a) 80 square feet b) 100 square feet c) 120 square feet d) 140 square feet

b) 100 square feet

Which of the following is listed as a type of mycotoxin that can affect dairy herd fertility? a) Penicillin b) Zearalenone c) Tetracycline d) Streptomycin

b) Zearalenone