Lectures 10-12 Flashcards
Cattle medicine
When are calves weaned in the wild?
8-12 months
Over how long is the weaning process in the wild?
2 weeks
Why can the presence of older weaned calves be good when weaning calves?
they older calves guide the younger ones to food which increases feed intake
In the two-step weaning process, how long are calves left with mothers?
4 days
In the two step weaning process what is used to stop calves sucking mothers?
anti-suckling device
What does the second stage of the two-step weaning process involve?
separating the cow and calf
What are 3 benefits of the two step weaning process to the calf?
Calves spent more time eating
Calves vocalise less
Calves walk less
What are two ways of separating a cow and calf in a modified weaning technique?
solid wall
fence-line
What technique of separation has been shown to reduce stress at weaning for calves?
fence-line
What is the minimum legal requirement for the number of times calves must be fed a day?
2
What are the 2 reasons why calves are underfed milk?
underfeeding encourages early intake of solid food
solid food is cheaper than milk replacer
What behaviour can bucket-feeding calves promote?
re-directed sucking behaviour
How long can re-directed sucking behaviour last for?
until adulthood
Why is fibre required in a calves diet?
to increase the rumen size
What two things are veal calves deficient in?
Iron
fibre
Are veal crates legal in the UK?
no
From what age must calves be in a pen with other calves?
8 weeks
What 3 welfare problems does individual housing of calves cause?
increased stress
reduced feed intake
learning deficiency
What legislation states the age after which calves must be housed together?
Welfare and Farm Animal Regulation
From what age must calves have drinking water?
2 weeks
What can larger udders predispose to?
solar ulcers
What is the term to describe the milk machine slipping of a teat due to poor conformation?
liner slip
What can liner slip predispose to?
mastitis
What can breeding for ‘double muscling’ cause in the cow?
dystocia
What is a proxy for metabolism?
heat output
What percentage of UK dairy cows are lame?
40%
What is the main reason for culling cows in the UK?
infertility
What percentage of UK dairy cows have mastitis?
40%
Are the heritability of reproductive and health traits in dairy cattle high or low?
low
What breeding scheme incorporates reproductive and health traits into its scheme?
Scandinavian breeding scheme
What two conditions in dairy cows have a higher prevalence in winter?
mastitis
laminitis
What type of mastitis used to be the most prevalent?
contagious mastitis
Why has there been an increase in environmental mastitis?
because of intensive housing
What are 3 factors associated with increased environmental mastitis?
increased cubicle use
poor cubicle design
poor cubicle management
What bacteria is associated with digital dermatitis?
Treponema
What is digital dermatitis associated with?
cows standing in slurry for long periods of time
What is the term for cows standing half in and half out of cubicles?
perching
What does cows standing half in and half out of a cubicle predispose to?
solar ulcers
What bacteria is the cause of the most common type of lameness in cattle?
Fusobacterium necrophorum
What about straw yards predisposes to lameness?
poor quality straw damaging interdigital skin
What disease can stony paths predispose cattle to?
white line disease
What are 3 alternatives to stony paths?
wood chip
recycled astroturf
stabilised soil
Are tethers in tie in stalls allowed in the UK?
no
What is a stereotypy shown in cows in tie in stalls?
tongue rolling
Does grazing behaviour increase or decrease milk production?
increase
What are four mutilations associated with cattle?
branding
castration
dehorning
tail docking
From what age must calves been given a source of fibre?
2 weeks
Is hot iron branding allowed in the UK?
no
What are the two branding methods?
hot-iron branding
freeze-branding
What are 3 alternatives to branding?
microchipping
electronic ID tags
retinal scanning
What tags can be used for cattle?
Radiofrequency Identification tag
Before what age should bull calves be slaughtered to avoid aggression?
18 months
What is a requirement around hot iron disbudding in the UK?
local anaesthetic must be used
What advantages of using analgesics and anaesthetics in disbudding have been shown by studies?
improved live weight gain
What is the name of the allele which causes no horns?
polled gene
What is a negative effect of breeding cattle for no horns?
decreased productivity
Is tail docking of cattle allowed in the UK?
no
What is the largest variable cost in milk production?
nutrition
What are the three types of dairy system?
cows at grass
composite system
high output system
Which system used in the UK has the lowest output?
cows at grass
What four metabolites can be measured in the blood as a diagnostic tool for assessing nutritional status?
urea
beta-hydroxybutyrate
glucose
NEFA
What is the biggest nutritional problem in underperforming cattle?
poor food intake
What are the 5 intake factors in order of importance?
feed intake energy intake protein intake water intake mineral and vitamin intake
What is the target BCS of a cow at calving?
3
What is the target BCS of a cow at peak yield?
2-2.5
What is the target BCS of a cow at drying off?
2.75-3
Why is maintaining BCS throughout the cow cycle not possible?
because at peak lactation the energy demands outweighs the food intake- negative energy balance
What is a clinical sign of ketosis?
milk having a ‘pear drop’ smell
What should be the DMI of a cow not in calf?
3%
What should the DMI of a lactating cow be?
2.5% +10% of milk yield in kg
Why is a negative energy balance caused in dairy cows at peak lactation?
because there is a delay between the milk yield increasing and the DMI increasing
When in lactation are most clinical problems seen?
early in lactation
What are 7 clinical problems associated with negative energy balance?
retained fetal membranes milk fever metritis LDA ketosis lameness mastitis
During what stage of pregnancy does energy requirements increase?
during the last 3rd
What is the main effect of weight loss during early lactation?
fertility problems
How is maintenance energy calculated?
maintenance + 20l
What is the term given to the energy which is available for gut microbes?
Fermentable Metabolisable Energy
What are two examples of quick fermentable energy?
starch
sugar
What are two examples of slowly fermentable energy?
cellulose
hemicellulose
If there is too much quick fermentable energy in the diet what can be overproduced in the rumen?
lactic acid
What is the QFE needed for?
to supply microbes with energy for protein synthesis
What kind of starch is able to by-pass ruminal degradation?
maize starch
Are fats degraded in the rumen or small intestine?
small intestine
What are the two aspects to protein?
Digestible Undegradable Protein
Effective Rumen Degradable Protein
What kind of protein is available to the cow?
DUP
What bacteria is associated with reducing the nutritional value of silage if secondary fermentation is occuring?
Clostridia
What substance is formed in secondary fermentation of silage?
butyric acid
What is able to reduce the palatability of silage?
mould
What is the term for leakage of silage clamp contents from the silage clamp?
silage effluence
What can reduce the risk of silage effluent?
not ensiling in the rain
Which regions of the UK are the wettest?
west
In which regions of the UK is silage made?
west
How should slurry be spread on the land to reduce environmental impact of this?
injected into soil rather than vaporised
How should slurry be treated before it is spread on land to reduce the biological oxygen demand?
it should be aerated
What is the pH of good quality silage?
4
What metabolite in the TCA cycle do ketones originate from?
Acetyl CoA
What does low milk proteins reflect about a cows health?
reflects long term poor energy status
Where do the majority of milk proteins come from?
microbial proteins
What is the problem with increasing concentrates in the diet to increase energy intake?
could cause ruminal acidosis
What 3 cattle feeds have increased FME?
second cut silage (more palatable)
bale silage
brewers grain
What 3 foods could be given to cattle to increase energy intake?
concentrates
maize starch
TMR
What FFA is produced more with more fibre?
acetate
What FFA is produced more with more concentrates?
propionate
What gas is produced more with a high fibre diet?
methane
What are three conditions which can cause lameness in cattle?
white line disease
laminitis
solar ulcers
What does a hybrid feeding system involve?
feeding TMR in cubicles and concentrates in the parlour
What are two things cows do which indicates digestive problems?
swishing tails
dropping cud
What percentage of cows should be using cubicles 1-2 hours post milking?
80-90%
What percentage of resting cows should be ruminating?
60%
What is the term for the number of times a cow should chew the cud before swallowing?
cud rate
What should the cud rate be?
50-80
Does a concave or convex para lumbar fossa indicate a full rumen and good rumen function?
concave
What should the rumen pH be if the cow is fed on concentrates?
5.5-6.5
What should the rumen pH be if the cow is mainly fed on roughage?
6-7
What rumen transit time is indicated by stiff faeces?
slow transit time (3-4 days)
What is the problem with slow rumen transit times?
reduced DMI because of the physical fill of the rumen
What rumen transit time is indicated by loose faeces?
rapid transit time
What kind of diets are associated with loose faeces?
low fibre diets
Which two places does the site of fermentation in a cow fed on low fibre shift to?
caecum
colon
Why could faeces become harder with low fibre?
shift in fermentation to caecum and colon causes decrease in colon pH killing the flora here, stopping fermentation and causing harder faeces
What are the two features are being looked at when faeces are sampled?
fibre length
presence of undigested food
What two things does undigested grain and long fibre in faeces suggest?
disturbed rumen fermentation
poor preparation technique e.g. not cracking maize grains open
What percentage of ad lib ration should be left over at the end of each day?
5-10%
What is the term to describe cows avoiding long fibre and picking out smaller higher energy particles?
sorting the ration
What should be done to prevent cows sorting the ration?
well mixed TMR
Why is chewing the cud important?
adds saliva to the food to lower rumen pH and keep it optimum
Which VFF is used by the mammary glands to produce milk fat?
acetate
Which FFA is used by the liver to produce glucose?
proprionate
What two things does increasing glucose production in the liver do to the milk?
increases yield
increases protein level
What three things does neutral detergent fibre assessment measure?
lignin
cellulose
hemicellulose
What does the neutral detergent fibre test correlate with?
DMI
What two things does the acid detergent fibre assessment measure?
cellulose
lignin
What does the acid detergent fibre assessment correlate with?
digestibility
What two things about the quality of fibre does the neutral detergent factor not show?
whether the fibre will stimulate rumination
whether the physical form (ie fibre length is right)
What is scratch factor?
a measure of the physically effective Neutral Detergent Fibre
Is fibre with a shorter or longer chop length easier to process by a forage harvester and in the silage clamp?
shorter
What device can be used to assess effective long fibre practically?
Penn State Forage Particle Separator
How many screens are in the Penn State Forage Particle Separator?
3
What percentage of fibre should be in the top sieve of the Penn State Forage Particle Separator?
8-10%
What percentage of fibre should be in the middle sieve of the Penn State Forage Particle Separator?
30-50%
What percentage of fibre should be in the bottom sieve of the Penn State Forage Particle Separator?
40-60%
What does a cud rate <50 show about the chop length of fibre?
it is too small
What does a cud rate of >80 show about fibre?
there is too much fibre
What are the two effects on the rumen of decreased rumen pH?
decreased carbohydrate digestion
lower pH favours lactic acid producing bacteria
What can the rumen not absorb if the papillae have not properly developed?
VFA
What is the main cause of sub-acute ruminal acidosis?
the rumen is not developed and papillae have not formed when the cows in early lactation were move to the calving diet
What are five ways of reducing the risk of sub-acute ruminal acidosis?
Acclimatise the dry cow rumen flora and papillae to lactation cow ration
Reduce quantity of concentrates fed at one time
Spread concentrate load throughout the day
Increasing buffering of rumen
Change rumen flora or add yeast to the diet
How long before calving should a transition diet be fed?
3-4 weeks
Below what pH does subacute ruminal acidosis start?
5.5
What is the problem with adding hay to the diet to increase saliva and improve rumen pH?
it increases physical fill and reduces DMI
How does yeast stimulate proliferation and activity of fibre digesting and lactic acid utilising bacteria?
by reducing oxygen
What can be used to monitor real time the pH of the rumen?
sensors in the rumen
