Parameters Useful to Monitor Health and Production of Dairy Herds

Adult Cow Disease

Average percentage of herd that is lame

< 25%

Metritis/endometritis incidence

< 5–25%

Subclinical ketosis (> 1.2 mmol/L)

< 10%

Clinical ketosis

< 2%

Left displaced abomasum

< 2%

Milk fever

< 2%

Retained fetal membranes

< 3%

Cut point for ruminal acidosis

pH < 5.5

Clinical mastitis monthly incidence

< 3% of lactating herd

Culling and Death Loss

Annual average overall cull rate

35%

Annual average selective cull rate

> 15%

Annual death loss

< 10%

Annual disease and injury culling

< 5%

Annual reproductive cull rate

5–10%

Percentage removed < 60 days in milk (lactation = 1)

< 4%

Percentage removed < 60 days in milk (lactation > 1)

< 6%

Udder Health and Milk Quality

SCC farm goal (US legal limit = 750,000 cells/mL)

< 150,000 cells/mL (or adjust for a dairy)

Standard plate count farm goal (US legal limit = 100,000 CFUs/mL)

2,000–4,000 CFUs/mL

Preliminary incubation count

2,000–6,000 CFUs/mL

Bacteria in Bulk Tank Cultures

Streptococcus agalactiae

0 CFUs/mL

Staphylococcus aureus

< 50 CFUs/mL

Staphylococcus spp

< 1,000 CFUs/mL

Mycoplasma spp

0 CFUs/mL

Environmental streptococci

< 1,000 CFUs/mL

Coliforms

< 500 CFUs/mL

General Reproductive Standards

Average days open

100–110 (ideally lower end of range to achieve 12-month calving)

Average gestation

279 days

Calving interval

13.5 months

Average days in milk

150

Percentage of cows < 90 days in milk

25%

Percentage of cows 90–180 days in milk

25%

Voluntary waiting period (VWP)

60–70 days for cows; 80–90 days for heifers

Days in milk at first breeding

VWP + 11 days

First-service conception rate

≥ 40%

Estrus detection

Overall, ≥ 60% (national average, < 40%)

Intervals between breedings

18–24 days for 65% of cows

Length of estrous cycle

18–24 days

Overall conception rate

≥ 40%

Services per conception

2

Definition of pregnancy rate (estrus detection rate × conception rate)

21-day interval

First-cycle pregnancy rate

> 30%

Percentage pregnant by three cycles

> 50%

Overall pregnancy rate

> 25%

Percentage of herd pregnant by 150 days in milk

> 75%

Pregnancy Diagnosis

When to do pregnancy checks

28–32 days after being bred

Ability to locate amnion

35–65 days

Membrane slip

Day 30 to term

Ability to locate fetus

65–95 days

Placentomes present

After 3 months of gestation

Ability to sex fetus

After 60–70 days of gestation

Pregnancy stage estimation by amnion size:

• 35 days

• 7 mm (½ finger)

• 42 days

• 15 mm (1 finger)

• 48 days

• 35 mm (2 fingers)

• 53 days

• 55 mm (3 fingers)

• 58 days

• 75 mm (4 fingers)

• 62 days

• 90 mm (palm)

• 65 days

• 105 mm (hand)

Pregnancy stage estimation by fetal crown-to-nose length:

• 70 days

• 1.5 cm (1 finger)

• 80 days

• 3.5 cm (2 fingers)

• 90 days

• 5.5 cm (3 fingers)

• 100 days

• 7.5 cm (4 fingers)

• 110 days

• 9 cm (palm)

• 120 days

• 10.5 cm (hand)

Postpartum Involution

Lochia (normal):

• Day 1–2

• Bright red, thick mucus, little smell

• Day 3–7

• Dark red, thin, odor not foul but objectionable

• Day 7–14

• Progressively less red to white to translucent, thicker, smell improving

Entire uterus palpable

2 weeks

Full decrease in size

40–45 days

Epithelialization complete

40–45 days

Occurrence of endometritis

> 26 days after calving

Full uterine involution

40–45 days post partum

Abortion

Normal embryonic loss (< 50 days)

< 10%

Average rate of early embryonic loss

15%

Normal rate of abortion

3%

Major infectious abortion agents

Bovine viral diarrhea, mycotic, leptospirosis, Neospora

Youngstock

Transfer of passive immunity

Excellent: ≥ 40% (> 6.1 g/dL)

Good: approx. 30% (5.8–6.1 g/dL)

Fair: approx. 20% (5.1–5.7 g/dL)

Poor: < 10% (< 5.1 g/dL)

Preweaning respiratory disease morbidity rate

< 15%

Preweaning mortality rate

< 3%

Lung consolidation (≥ 3 cm²) at weaning

< 15%

Average daily weight gain

≥ 800 g