Lecture 17: Dairy Nutrition 1 (Exam 2) Flashcards
During peak lactation how much DM does a dairy cow eat
3.7% of BW
What does TMR (Total Mixed Ration) contain
- Corn
- Silage
- Hay
- Ground corn
- Soybean meal
- By product feeds
- Mineral & vitamins
What are the different type of milking systems
- Portable milkers
- Barn milking
- Milking parlors
What are the different type of milking parlors
- herringbone
- Swing over
- Rapid exit parallel
- Rotary
- Robotic/automatic
Describe portable milkers
- Only capable of only milking 20 cows @ a time
- Sick animals & farm shows
Describe barn milking system
- Used if cows are tied in the bar
- Confined to a certain space
- Use 1 station per 2 cows
Describe a herringbone parlor
- Milking machines are in the middle
- 2 rows of cows on ea side w/ a central pit where the workers are
Describe swingover parlor
Herringbone type but w/ only one set of milkers
Describe rapid exit parlors
All cows exit both sides @ once
Describe a rotary parlor
Cow steps on when an empty stall is ava
Describe a robotic/automatic parlor
Can allow up to 3 times per day milking
Describe a typical life of a dairy cow
- Day 0 -> calve; heifers calve @ 2 YO
- Day 0 - 120: Open/not pregnant & lactating
- Day 120 - 480: Pregnant 280 D but lactates until day 350
- Day 340 - Lactation ends (dry-off) 60 days before next calving
- Dry period = 60 D
- Usually sold after 3 to 5 lactations
What is heat detection rate (HDR)
cows bred divided by # eligible to breed over 21 d period
What is pregnancy rate (PR)
of cows pregnant divided by the # eligible to get preg over 21 d period
What does HDR + PR affect
The calving interval & days open
What is the calving interval
- ~ 400 days or 13.2 M
- The time btw/ calvings
What are “Days open”
- Time from calving until conceptions
- ~166 D
- Goal is to have 75% cows bred by 150 days in milk (DIM)
What is “days to first service (voluntary waiting period)
- Min # of days from calving to 1st service
- Ideally 45 to 60 D
- Commonly 90 to 100 days
Services/conceptions = ?
2
When is peak milk production during lactation
30 to 150 days
What can affect peak milk production
- Breed
- Nutrition
- Season of the year
- High producing animals peak later compared to lower producing animals
What are the types of dairy production systems
- Confinement dairies
- Pasture based systems
Describe confinement dairies
- Stanchion barns (tile stalls & milking barn system)
- Free stall + Parlor
- Dry lot + parlor
- Compost bedded pack barn + parlor
Describe a pasture based system
- Permanent pasture + supplement feeding
- Intensive grazing = graze 6 to 7 months & confined for 5 to 6; feed savings; milk is high variable due to changing forage quality
- Grazing + supplemental feeding = variation in forage
- Grazing + seasonal breeding = Lower feed costs; match forage ava to nutrient needs; focus breeding into 2 to 3 so calves born in late winter
