Exam 2: Lecture 21 - Beef nutrition 1 Flashcards
what are the differences between beef cow-calf vs dairy
- beef cows are NOT small unproductive dairy cows
- beef cows are scavengers and dairy cows are factories
what is a cow-calf operation
- can be large, medium, or small
- 3/4 raise commercial cattle to be marketed for consumption
what is the goal of background and stocker operations
goal is to grow to weight and enter feedlot
what is backgrounding
weaning calves kept on dry lot and fed roughage and grain
what is a stocker
weaned calves grazing pasture, some grain supplementation
what is a finishing operation
grow to finished weight for slaughter
what % do small scale beef cattle operations account for
90%
what is the traditional beef cattle operation
- mostly small scale
- permanent herd of cows, may have bulls
- fed pastures, vitamins, and minerals
- about 2/3 calves from cow-calf operations are sold after weaning
how are calves from cow-calf operations sold
auctions, specialized sales, or brokers
where do feeder calves go
to backgrounding or stocker operations
T/F: large operations tend to utilize more technology
true!
what are the 4 main goals of cow-calf operations
- maintain repro efficiency
- minimize calf morbidity and mortality
- keep cows cheaply over the winter
- market a calf that someone wants to buy
what is the OVERALL goal of cow-calf operations
maximize number of calves sold
what is avg weight of mature angus cow
1000-1300 lbs
what is avg weight of newborn calf
65-100lbs
what is avg weight of stocker cattle
400-700lbs
what is avg weight of weaning weight (6 months)
500 lbs
what is avg weight of finished weight cattle
1000-1300 lbs
what is dressing percentage
term for the carcass and is calculated
how is dressing percentage calculated
hot carcass weight / live animal weight
what is the average dressing percentage
59-64% but average is 63%
what is calf crop for beef herd
> 90% for well managed herds
what is the calving interval for beef
365 days (400 for dairy)
what % of cows in heat by 60 days post calving for beef
80%
what is the beef calf weaning weight
45-50% of cows weight
what is the typical length of breeding season for beef
65 days for cows, 42 days for heifers
when do cows typically resume estrus cycle post calving
40-60 days
what is the average age of beef weaning
180 days ( 6 months)
what is the % of crossbred beef cows
100%
what is the average beef cow age
7-8 yrs
what is the avg beef cow culling rate
5-10%
what should be the weaning weight of beef calves?
A. 300 lbs
B. 400 lbs
C. 50% of cows bw
D. 60% of cows bw
C. 50% of cows bw
what is the goal of backgrounding and stocker calves at pasture
grow feeder cattle to a weight for entering feedlot
what is the goal weight of feeder calf entering the feedlot
700-800 lbs
how many calves do most buyers purchase and why
uniform groups of 40 because they are fed similarly and vaccinated similarly
what are the 4 important things to look at for nutrient requirements for beef cattle
- energy
- protein
- major minerals
- minor minerals and vitamins
what is NEg
net energy needed for weight gain
what are the 2 factors of NEg
weight gain and body condition gain
what is NEm
net energy for maintenance
why is net energy the best thing to use for cattle
it accounts for heat loss
Crude protein is turned into DIP which is then used by what to make metabolizable protein
used by microbes
why are calcium and phosophorus \ major minerals for beef cattle
required for milk production and growth
are grains or forages higher in Ca
forages
T/F: grains and corn by-products are higher in P and lower in Ca
true!!
why is the Ca:P ratio important for steers
because of development of urinary calculi
what major mineral is this?
low in lush spring grass and grass tetany is a risk
magnemiusm
what major mineral is this?
high in forages, low in grains
potassium
when is sulfur particularly needed
when urea is added because toxicity is a concern
what are the trace minerals needed to have adequate mineral supplementation
Co, Cu, I, Fe, Mn, Se, Zn
what vitamins are required for beef cattle
A, D, E
which component of protein is associated with energy requirements?
A. degradable intake protein (DIP)
B. undegradable intake protein (UIP)
C. metabolizable protein (MP)
D. Crude protein (CP)
A. degradable intake protein (DIP) because it is used by microbes.
B is incorrect because it is a by-pass protein not digested in rumen
C is incorrect because it is the protein available to the animal
D is incorrect bc it is a % of protein in diet
what are the 4 things we should consider when adjusting nutrient requirement for beef cows
- stage of production
- environmental adjustments
- cow size and breed
- BCS
what are the environmental adjustments for beef cattle
lower critical temp leads to cold stress and upper critical temp leads to heat stress
what is the thermoneutral zone for beef cattle
32-77 degrees, a point where they dont have to use energy to maintain body temp
