Exam 2: Lecture 17 - Dairy nutrition 1 Flashcards
what are the 2 basic rules of dairy production
- make more milk
- reduce costs (as long as it doesnt interfere with #1)
what is the average BW of a holstein cow
about 1350 lbs
during peak lactation, how much DM/d does a holstein cow consume
3.7% of BW, about 50lbs DM/d
what does TMR stand for
total mixed ration
what does TMR usually contain
corn silage, hay, ground corn, soybean meal, other by-product feeds, minerals and vitamins
what are the 3 main types of milking systems
portable milkers, barn milking system, milking parlors
describe when a portable milker is used
less than 20 cows, at shows, sick animals, or field animals
describe when a barn milking system is used
if cows are tied in the barn, 1 station per 2 cows
what are the 5 types of milking parlors
herringbone, swingover, rapid exit parallel, rotary, robotic (automatic)
describe what a herringbone milking parlor is
milk machine in middle with 2 rows of cows on each side and central pit for workers
describe what a SwingOver milking parlor is
one set on milkers, swing from one side to the other
describe what a rapid exit parallel milking parlor is
all cows exit both sides at once with a fast reloading
describe what a rotary milking parlor is
cows step on when stall is available, milked while it turns around
describe what a robotic (automatic) milking parlor is
feed to lure cows in, milked up to 3x a day
what is the typical like of a day 0 (calve)
heifers calve (freshen) at 2 years of age
describe days 0-120 of a dairy cow
open (non-pregnant), lactating
describe days 120-400 of a dairy cow
pregnant 280 days (nine months), lactates until day 340
describe day 340 of a dairy cow
lactation ends (dry-off) 60 days before next calving
what is the dry period of a dairy cow and when are they usually sold
dry period = 60 days
usually sold after 3-5 lactations
what is heat detection rate (HDR)
of cows bred divided by # eligible to breed over 21-d period
what is pregnancy rate (PR)
of cows pregnant divided by # eligible to get pregnant over 21-d
What do HDR + PR affect
calving interval and days open
what is the calving interval
about 400 days or 13.2 months
what does day open mean and what is the national average
time from calving until conception
avg = 166 days
The goal of days open is to have __1__ cows bred by ___2___ days in milk (DIM)
- 75%
- 150 days
what is the days to first service
minimum # days from calving to 1st service
what is the ideal and common amount of days to first service
ideal = 45-60 days
commonly = 90-100 days
how many services/conceptions are there usually
2
in peak lactation, how much DM is the typical holstein cow consuming?
A. 2.5% of bw
B. 3.2% of bw
C. 3.7% of bw
D. 4.1% of bw
C. 3.7% of body weight
when does lactation end post calving
around day 340 post calving
how much peak milk production is there during lactation
30-150 DIM
what are the effects of peak milk production
peak and daily yield affect by breed, nutrition, season of year
T/F: High producing animals peak later in the lactation curve compared to lower-producing animals
true!!
what are the types of confinement dairies
- stanchion barns
- free stall + parlor
- dry lot + parlor
- compost-bedded pack barn + parlor
what are the pasture based systems
- intensive grazing
- intensive grazing and seasonal breeding
- permanent pasture and supplemental feeding
what does intensive grazing system look like
graze 6-7 months of the year, confinement for 5-6 months, feed savings, and milk is highly variable due to changing forage quality
what is the challenge of a grazing + supplemental feeding system
variation in forage quality
what does a grazing + seasonal breeding system look like
focus breed into 2-3 calves so calves born in late winter to early spring
match forage availability to nutrient needs (peak lactation occurs during peak forage)
lower feeding costs
what is the TYPICAL calving interval for a diary cow?
A. 12.2 months
B. 12.8 months
C. 13.2 months
D. 13.8 months
C. 13.2 months (about 400 days)
what type of feed do we use in a confinement dairy feeding system
- hay and grain
- component feeding (corn silage, grain mix, hay)
- Total mixed ration (TMR)
T/F: a cow can consume enough forage to meet her energy and other nutrient needs during a lactation
FALSE!! they CANT so you need a concentrate mix to provide energy, additional protein, minerals, and vitamins
concentrates (grains) should always be limited to no more than _________ of the ration. Why??
60%
because more than 60% of grain leads to pH issues in rumen b/c lack of rumination, alter rumen VFAs, and decreased milk fat
T/F: the issue with hay and grain feeding is consuming enough nutrients depends on the cow eating enough of both hay and grain
TRUE
what are the 2 strategies of component feeding
- feed forage before grain
- feed grain (energy) + protein + vitamin/mineral mixture
how long before offering grain should we feed forage for a component feeding
feed forage 30 mins to 1.5 hours before offering grain mixture
what carbs are rapidly fermented in the rumen
barley and corn
what carbs are slow fermentable in the rumen
citrus pulp and beet pulp
describe how we do TMR feeding
weighing and blending all components into a complete ration to meet nutrient requirements
what are the benefits of TMR feeding
- each bite in nutritionally balanced
- reduced sorting of feed
- can easily measure DMI
- larger selection of feeds can be used
- cows fed TMR tend to produce more milk
what are feed refusals called
Orts…. lol
high producing cows unable to meet energy requirements in _____1_____ from diet alone. Why??
- early lactation
because DMI is limiting factor
NDF should be no less than __1__ and most should come from ____2____
- no less than 30%
- come from forage
for protein and feeding dairy cows, what is important to remember
need rumen degradable and undegradable protein
As peak milk is reached, bw ______1_____ because body fat is being used for ___2__
- decreases
- milk energy
what are the #s for a dairy BCS chart
1-5
what is the limit on grain inclusion in a ration for dairy cows?
A. 50%
B. 60%
C. 70%
D. 80%
B. 60%
