Beef Final Flashcards
Cost to maintain suckler cow and calf
€635
Cost to maintain suckler cow, & feed costs out of this cost
€552
Feed costs - €420
Typical feed input of feed in Ireland: grass, silage, concentrates %
60% grass, 30% silage, ~8% concentrates
3 most important stages of a suckler cow
Breeding, calving, weaning
Target BCS for mid-pregnancy, calving and breeding
Mid-pregnancy - 3
Calving - 2.5
Breeding - >2
What % seasonal weight gain from grazed grass for cows?
100%
Loss of 1 BCS score contributes how many MJ ME and UFL?
3,200 MJ ME
~280UFL (11.4MJ ME/UFL)
0.7 BCS = how many UFL?
~200UFL
220UFL = how many kg of silage
300kg DM silage (DMD 67% = 0.73 UFL/kg)
3 BCS groups
Fat - BCS >3.5
Target - BCS 2.25-3.5
Lean - BCS <2
Once a calf is 7months old (>200d), what % of its nutrient requirement should be from feeds other than milk?
75%
The calf share of cow requirements at 6, 7, 8, and 9 months gestation and PDI requirements
6 - 0.56 - 47g
7 - 1.08 - 88g
8 - 1.86 - 148g
9 - 2.93 - 226g
Maintenance UFL/day calculation
1.4 + 0.6 Wt/100
What % of calf weight in gain in the last 3 months of pregnancy
90%
For each 5 kg in calf birth weight in last trimester add/subtract how many g PDI
20g PDI
Moderate quality grass silage % DMD
62-68% DMD
Cows in good BCS (~3.0) can be restricted to what % of feed requirements to reduce winter feed cost
75%
Sufficient protein and energy intake for cow
535g PDI
6.1 UFL
What % BW does a cow consume?
1.35%
Crude protein content of grass, silage and straw
Grass 17-27%
Silage 13-17%
Straw 3-4%
Restricted feeding is how much silage
30kg fresh weight average equality silage or 25kg of good quality silage
Suckler cow requires how many UFL per litre of milk produced
0.45 UFL per litre
Continental beef breeds produce how many litres of milk / day indoors
5-8 Litres
600 kg cow needs how many UFL per day while maintaining body condition
7.8 to 9.1 UFL per day
Maximum % of kale and turnips in the diet
80%
What minerals are kale and turnips low in?
Copper and iodine - requires supplementation
Critical pre-calver trace minerals
Copper, iodine, selenium
Intake potential of cattle: Lactating suckler cow, Young cattle 350kg, store cattle
Lactating suckler cow - 12-13kg DM/day
Young cattle 350kg - 7-8kg DM/day
Store cattle - 8-9kg DM/day
Rumen cannot function without a minimum of what % roughage
40%
Critical time for cow nutrition is when?
6 weeks before calving through to 6 weeks after service
BCS <2 at calving means they will be how much slower going back in calf
2-3 weeks slower
PGHM requirement for cows at breeding season
1,400kg DM/ha
A minimum requirement of what % of dietary DM as long fibre
8-10%
Silage pit tonnes DM calculation
Dimensions of pit X 154 = __tonnes DM
Space allowance for suckler cow in slatted shed and straw bedded shed?
Slatted shed - 3m2/head
Straw bedded - 4m2/head
What % of EU beef carcasses now originates from progeny derived from the dairy herd
~60%
Milk % DM requirement per litre of water for calves
12.5%
Target is to get calf to grow from ___kg at birth to about ____kg at ____weeks
40-45kg
100kg
15 weeks
Under EU law you cannot purchase a calf under what age
10 days of age
Normal body temp of calf
38.6-39.3oC
Calf mortality should not exceed what % in the period before weaning
3%
Products often incorporated into the calf concentrate diet to improve palatability?
Molasses, molasine meal or yeast cultures
Calf concentrate composition: CP, energy, oil, fibre, texture
CP: 17-18%
High energy (0.95 UFL/kg, 11 MJ of ME/kg)
Oil: less than 4%
Fibre: 8-10%
Coarse texture
Each additional kg of milk results in:
Weaning weight, slaughter weight, carcass weight
Weaning weight - +6.5kg
Slaughter weight - +5.2kg
Carcass weight - +2.72kg
How much exceeding targets helps performance?
+€55 margin per head
Which immunoglobulins absorbed better than others?
IgG and IgA absorbed more efficiently than IgM (larger molecule)
% reduction of IgG content from colostrum to transition milk?
54-56% reduction
Maximum absorption of immunoglobulins how long after birth?
Within 2 hours
What % of calves suffer from Failure of Passive Transfer on antibodies on Irish Farms
40-50%
The ability of the intestines to absorb IgG starts to decline progressively after ___ hours and ceases after ___ hours from birth
4-6 hours
24 hours
Antibodies in colostrum decrease by what %/hour from calving
3.7%/hour
2 layers of the rumen wall
Musculature
Absorptive epithelium (mucosa)
Function of mucosa in rumen
Absorbs VFAs
Ensure calf is consuming at least __kg concentrates for __ consecutive days before weaning
1kg
3 days
% CP and % fat in milk replacer
22-25% CP
18-20% fat/oil
Minimum carcass fat score allowed
2+
% increase in Irish dairy cow numbers in 10 years
~40%
% of beef carcasses of dairy origin
~60%
Policy ambition to reduce slaughter age by…
3 - 3.5 months
Growth rate of 1st winter
600g ADG
230kg November to 300kg in March
Expected ADG at 1st summer at grass
1.25-1.3kg/day
Target pre-grazing cover
1200-1400kg DM/ha
Average grass utilisation on farm
70-75% but ideally 80% in very good conditions
Parasite control dosing when?
3, 8, and 13 weeks after turnout
Expected ADG at first winter?
0.5/0.6 kg/day
Weights at turnout for second grazing season for bullocks and heifers
Bullocks 300kg
Heifers 275-290kg
ADG for second grazing season
+0.9kg/day
2nd winter ADG
0.8-1kg/day
Feed for 2nd winter
1t silage/head/month
4-5kg concentrates
Output value per ha calculation
Stocking Rate x Output per LU x Price (€/kg) = Output Value per ha
What is the main driver of profitability on Irish suckler farms?
Striking a balance between maximizing output and controlling costs
What proportion of a suckler cow’s annual feed budget should come from grazed grass?
60%
What is the main competitive advantage for Irish livestock farmers in feed management?
Abundant grazed grass
During late pregnancy, cows in good BCS can tolerate an energy deficit of how much per day?
1.5UFL
First-calf heifers require supplementation of concentrates post-calving until turnout. What is the recommended daily amount?
1.5-2.5 kg
Why should kale and turnips be grazed before flowering?
To prevent poisoning due to high nitrogen content
How much concentrate should be added to the diet of thin suckler cows?
1kg/day
What is an important nutritional balance during the weaning transition?
Controlled intake of chopped hay or straw (<200g/day)
What is the impact of early-life nutrition on carcass fat development?
Influences preadipocyte differentiation and hypertrophy
What is a key feature of the finishing ration to improve carcass quality?
Strategic use of concentrates
What is the most biologically efficient period for converting nutrients into body weight gain in calves?
First 6 months of life
What is the critical threshold for faecal egg counts (FEC) in calves to indicate a need for gut worm treatment?
> 200epg
What is a recommended practice for reducing the worm challenge in young stock?
Mixing younger animals with sheep
What grazing management strategy minimizes under-grazing and maintains grass quality?
Grazing to 4 cm in the first rotation
What percentage of the worm population resides in the animal?
5%
Compensatory growth is more evident following which type of restriction?
Winter restriction
By how much should concentrate levels increase for every 5% drop in silage digestibility (DMD)?
1.25–1.5 kg
What is the carbon footprint reduction per kg of carcass achieved by diverse and legume swards?
15%
What is the gross margin reduction per head for every €10/tonne increase in concentrate price?
€18
What is the primary genetic cause of double muscling (DM) in cattle?
A mutation in the myostatin gene (GDF8)
How many disruptive variants of the myostatin gene are identified in cattle?
6
What is the term used for naturally occurring changes in the genetic blueprint?
Mutations
What is the common name for the F94L myostatin mutation?
Limousin gene
Which myostatin variant is known as a partially dominant mutation?
Q204X
What is the effect of missense mutations in the myostatin gene?
They increase muscularity without causing double muscling.
What is the muscle-to-bone ratio in double-muscled cattle?
9:1
What is a key economic advantage of double-muscled cattle?
Higher meat yield
Why is calving difficult for DM dams?
Narrow pelvic openings
What is the cost of genotyping an animal for the myostatin gene?
€22
What is the primary benefit of DM carriers (heterozygous for the DM gene)?
Comparable calving ease to normal cattle
Who first documented the double-muscling syndrome in cattle?
George Culley
Which gene is responsible for double-muscling in cattle?
GDF8 (Myostatin)
What is the consequence of homozygous animals carrying disruptive mutations like nt821?
Higher carcass yield with increased birth weight and calving difficulties
What is the probability of producing a double-muscled calf when two carriers (C x C) are bred?
25%
If a double-muscled animal (DM) is bred with a carrier (C), what percentage of the offspring will be double-muscled?
50%
Which breed commonly carries the C313Y myostatin mutation?
Piedmontese
What is the observed increase in lean meat yield in heterozygous animals compared to normal cattle?
3–10%
Why is meat from double-muscled cattle considered higher quality?
Increased polyunsaturated fats and tenderness
