Introduction to Animal Husbandry Flashcards
What is wind-sucking/crib-biting?
A stereotypical equine behaviour created by inappropriate husbandry
What does wind-sucking/crib-biting result in?
Mastication promotes saliva production for acidic digestion
What are the general factors that can increase the likelihood of dystocia?
Stress Genetics Poor feeding
What are the potential factors leading to the incidence of mastitis?
Over-milking Poor milking technique Poor cleanliness and hygiene Poor housing conditions Cross-contamination between individuals
When did domestication begin?
Approximately 10,000YA
What advantages are offered by domesticating animals?
Food Fabric Friendship Force Fuel
What factors were animals originally domesticated for?
Easily fed Rapid growth rate Breed freely
What reasons might mean that some species were not considered beneficial to domesticate?
Poor feed conversion in diet Carnivores Growth rate is too slow Difficulty breeding in captivity Nasty/unfavourable disposition Tendency to panic
What does the term ‘feral’ mean?
Return of domesticated animals to the wild environment
What are the main types of grasses domesticated?
Wheat Maize Rice
How long is the gestation period for a sheep?
5mo
How many months are horses pregnant for?
11mo
Cows and horses are both what kind of breeders?
Long day breeders
Are sheep long or short day breeders?
Short day breeders
What are homeothermic endotherms?
Animals that maintain their constant body temperature at 37-38.5ºC (mammals) or 40ºC (birds)
How do endothermic animals maintain their internal body temperature?
Metabolism
What is the significance of maintenance energy, ME?
Maintaining of structural integrity
What is production energy?
Energy used for growth, performing work, reproduction, lactation
What are the main routes via which energy is lost?
Evaporation
Convection
Conduction
Radiation
How is energy lost through conduction?
Direct transfer of KE e.g. transfer of heat between touching objects
What is evaporation?
Vaporisation of surface H2O - latent heat of body
What is evaporation affected by?
Ambient temperature
Humidity
Air movement from skin + respiratory systems
Of conduction, convection, radiation and evaporation, which of these are considered sensible and insensible heat losses?
Sensible = conduction, convection, radiation
Insensible = evaporation
What animal adaptations are there towards their seasonal environments?
Seasonality of reproduction
Pelage
Metabolic rate
Appetite
Growth
Behaviour
What is radiation? What is it dependent on?
Loss of heat as electromagnetic radiation
- dependent on emissivity of body surface ie. darker coats radiate and absorb more heat
What factors affect conduction transfer of heat?
Rate is influenced by area of animal in contact ie. lying down vs standing
Thermal conductance of substrate - straw, mud
What is convection?
Transfer of heat contained in a gas or liquid by movement of that mass
What sources provide heat gain for an animal?
Radiation
Useful dietary E
How is heat balance managed internally within animals?
Negative feedback
What behavioural adaptions are desirable within cold environments?
Huddling
Withdrawing extremities
Seeking shelter
What physiological heat generating processes are there for enduring cold environments?
Increasing surface insulation - plumage, pelage
Increasing tissue insulation - SC fat
Countercurrent heat exchange
Thermogenesis - shivering, brown fat in neonates
What behavioural heat dissipating processes are possible within hot environments?
Maximising body SA - thermal windows
Seek air movement (aids convection) and shade
What physiological adaptations are possible for enduring hot environments?
Minimise surface insulation
Increase emissivity - decreased plumage or pelage
Minimise tissue insulation - conduct heat to body surface through vasodilation
Minimise heat production - inactivity, decreased food intake
Evaporative cooling - panting, sweating, licking fur
What does a comfort zone refer to?
An animal’s preferred range of ambient temperature within the TNZ
What is the TNZ?
Thermal neutral zone - between the lower and upper critical temperatures
What factors influence heat balance?
Body size and shape
Body insulation
Age of animal
Nutrition
Shelter
Relative humidity
Do larger or smaller animals produce most heat per unit weight?
Smaller animals per unit weight
How is the thermal gradient for body insulation calculated?
Tcore - Tsurface = thermal gradient
What is body insulation proportional to?
Depth of coat
Ability of coat to trap air
Which of the domesticated species have spring and autumn moults?
Cattle
Horses
Pigs
Dogs
Cats
Which species only moults in the spring?
Sheep
What does the ambient temperature have to be for reflex vasodilation to occur at extremities?
Ta < 5ºC
Why is heat conduction better in adult animals than young?
Young animals have not been able to develop sufficient SC fat for insulation
Why do young animals have higher LCTs and narrower TNZs than their adult counterparts?
Difference in body size and shape
Poor tissue and surface insulation
Wet birth coat
By what means can neonates survive exposure to cold conditions when they are wet?
Increasing their metabolic rate - limited body reserves of glycogen and lipid
Activating brown adipose tissue
Non-shivering thermogenesis
Early colostrum intake
Describe the typical features of an unconfiend animal environment.
Common in hilly and mountainous regions
Land is often unsuited for improvements
Often extensive grazing is most efficient use
May require enclosing at specific times
What is ‘hefting’?
Refers to the ability of an animal to learn the location of its home farm when placed on areas of extensive grazing.
Describe typical fields and paddocks as an animal environment.
Enclosed by walls, fences, hedges, ditches
Increased labour effort for maintenance
Increased costs for maintenance
Affected by stocking density, fertilisation, sward type and shelter
Describe the environment that housing/accommodation has to offer.
Protection for animals and labourers from adverse weather
Protects lands from animals in winter - poaching, overgrazing
Increased stocking densities
Most intensive management and control - indoor lambing
Increased productivity
What features must a building’s design consider?
Walls alone or walls + roof
Floor - natural, solid, slatted
Access to yard or pasture
What considerations are there for ventilation in animal housing?
Replenishing depleted O2
Preventing accumulation of CO2 (<0.3%) and NH3 (<25ppm)
Prevent accumulation of moisture, heat, dust particles and disease through aerosol transmissoin
What problems are associated with inadequate ventilation levels?
Increased incidence of disease
Reduced appetite (+ productivity)
Condensation problems
Increased susceptibility to chilling
Why does temperature need extensive control in animal housing?
Daily monitoring of minima and maxima
Adults rarely require modifications, unless:
- horses - clipped, rugging up
- cattle - clipping
- sheep - shearing
Young animals require frequent temperature modification
- altricial species always - kittens, puppies, chicks, piglets
- precocial species frequently - lambs, foals, calves
What factors need to be considered when achieving an effective and healthy social system within housed animals?
Preferred group size
Group composition
Group stability
Stocking density
What different space allowances are there?
Legal minimum requirements
Species specific
Animal size - breed, fleece, horns
Specific needs - wing-stretching, perches
Composition of group - hierachy
Production level
Segregation of living area - feeding, cubicles, kennels, loafing, bedding, latrine
What must waste disposal systems consider?
Number of livestock kept
Duration of housing
Volume of excreta/animal/day
Fertiliser potential
Area of land for disposal
Pollution risks
Methods and cost of collection, storage and use
How frequently can a dairy cow receive veterinary medications for?
3x/yr
What happens to the waiting time for drug withdrawal period with organic animals?
It is doubled for organic animals
What common additives used on farms are not permitted on organic farms?
No injectable hormones
No synthetic fertilisers or pesticides
How frequently may an organic meat-producing animal receive veterinary treatments?
3x/lifetime
What ages are steers generally finished at in the UK?
18-24mo
At what ages are bulls generally slaughtered for meat? Why?
12-14mo, as they have reached sexual maturity
What is biological efficiency influenced by?
Reproductive efficiency
Lactation ability
Growth and development
Longevity/replacement rate
What is fecundity?
The actual reproductive rate of an organism or population, referring to the number of offspring resulting from the number of gametes produced.
What different factors comprise reproductive efficiency?
Fertility
Fecundity
Breeding frequency
Peri/post-partum problems - maternal, neonatal
Generally what is the ideal BCS preferred at the point of mating?
3
For maiden heifers, by puberty what percentage of their mature weight should they have reached?
45-50% of mature BW
What percentage of their mature weight is desired for heifers when they are first mated?
65% of mature BW is sought
What is the typical butter-fat content and milk-protein percentage in a cow’s milk?
- 5% butter-fat
- 2% milk protein
In mares’ milk, what is the typical milk protein % and butter-fat %?
Milk-protein = 2.7%
Butter-fat = 1.6
What is the typical milk-protein content and butter-fat content in a lactating bitch? And in a ewe?
Bitch: milk-protein 9.5%
butter-fat 8.3%
Ewe: milk-protein 5.5%
butter-fat 5.3%
What are the two main types of feeding associated with dairy cows?
Lead/yield feeding
Flat-rate feeding
According to sigmoidal growth curve, at what point does puberty occur? What often happens at this stage in an animal’s life?
Puberty occurs just at the end of the self-accelerating phase of growth and at the start of the self-decelerating stage.
Generally most livestock will be slaughtered upon reaching puberty if they are not replacements.
What value is determined as the cut-off point for selling milk for the SCC?
400,000 cells/L
What principle for the lead/yield feeding technique follow?
This feeding regime matches nutritiional accordingly with the milk yield, to promote further production of milk
How does flat-rate feeding work?
This feeding regime maintains a gradual plateau throughout
Calves are not weaned off as quickly despite a lower milk yield throughout
* lower E causes lower milk protein and buttermilk content
What is the principle with compensatory growth?
Growth is halted by feed restriction ie. during winter
This is followed by ad libitum in spring to help animal reach mature weight desired
Why is it important to control DLWG when breeding cows?
To prevent fat from being laid down and dystocia
Why is it important to carefully monitor DLWG in bulls?
To prevent the occurrence of cartilage problems in the stifle and hock that often occur when forced to grow too fast
What do growth co-efficients measure?
Growth rate of a particular anatomical region compared with that of the whole body.
What is one of the problems associated with UK beef breeds in comparison with their continental counterparts?
UK breeds reach ‘fat phase’ faster therefore quickly lay down fat reserves as early maturers that therefore rear slowly.
Continental breeds lay down bone and muscle earlier therefore rear faster as late maturers.
What is the overall transition in the chemical composition of animals?
CNS -> bone -> muscle -> fat
What basic components do plants require to survive?
Inorganic elements
N2
H2O
CO2
Solar E
What does the general H2O content range from in the main domestic species? What is it for ash?
H2O ranges from 55-60%
Ash ranges from 2.8-4.8%
What happens to dry matter content of animals with age? Why is this significant?
It increases with growth
As animals mature, each unit weight gain contains more fat and less protein, minerals and water
- therefore confirming the occurrence heterogeneous growth
- justifies slaughtering meat animals around the inflection point of their sigmoidal growth curve
Define a nutrient.
Any chemical element or compond in the diet that supports, either structurally or energetically, normal reproduction, growth, lactation or the maintenance of life processes.
Describe the main features of carnivores and their diets.
Prehension - grasping canines and cutting carnassials
- powerful bite
Mastication - minimal
Diet - E-dense, easily digested foods require expansive stomach to maximise use of opportunistic kills
Digestion = monogastric
Why is tartar accumulation a common occurrence with today’s dogs?
Current canine diets lack much friction when masticating
Descrive the main features of a herbivore and their diet.
Prehension - ruminants: blunt, tender muzzle
prehensile tongue
* specialise in longer, lusher grasses
- equidae: prehensile upper lip
less tongue involvement
nipping incisors
* specialise in shorter, coarses grasses
Mastication: hypsodont grinding teeth + copious salivary secretions
What is the significance of copious salivary secretions in herbivores?
Alkali secretions are essential for neutralising stomach acids prior to entering intestinal tract.
How much time during the day do ruminants and horses spend grazing?
Ruminants - graze 33% day (rest 33%, ruminate 33%)
Equidae - graze 50-60% day = trickle feeders
What is the significance of the symbiotic microorganisms within herbivore digestive systems?
Mammals CANNOT synthesise cellulase
Some bacteria and protozoa can digest cellulose
- within the gut, microorganism populations flourish on ingested grasses and digesting the complex chemicals
- this releases simple fermentation products (VFAs) that the host mammal can absorb along with the microorganisms that serve as a protein source
Approximately how much of a cow is accounted for by their rumen?
~150kg
How does a generalised herbivore digestive system function?
- Food enters stomach via oesophagus
- Enzymatic digestion degrades food bolus; very little absorption.
- Stomach contents enters SI where absorption is very high and there is very little further enzymatic digestion.
- On reaching the caecum and colon (hindgut), microbial digestion degrades stomach contents further into VFAs and absorption is high.
- All remaining material is excreted via rectum into environment as faeces.
What is the route for consumed material within a cow’s digestive system?
Reticulum -> rumen -> omasum -> abomasum
What is the advantage of ruminant digestive systems? What is the disadvantage?
Enables ruminant to be able to use ‘inaccessible’ nutrients from forage feeds.
All food molecules have to be processed by the symbiotic microorganisms first, therefore there is no guarantee of the nutrients reaching the ruminant’s own tissues.
What are the advantages of hindgut fermentation seen in horses and rabbits? What is the main disadvantage?
Permits animal to be able to utilise otherwise ‘inaccessible’ nutrients from forage feeds following absorption of accessible feeds.
Can evacuate fermentation vat rapidly for flight.
These animals cannot ruminant therefore less digestion of fibre is possible
What are two important considerations with hind gut fermenters?
Small amounts of feed are required regularly to prevent gut stasis from occurring
Risk of rupture if overfed or fed excess dry food
How is digestibility (%) of a nutrient or E calculated?
Amount ingested - amount in faeces x100
amount ingested
* better digestibility is ideal as the animal will benefit more
What are the assumptions made when calculating digestibility?
- That faeces only contain undigested food
- That all ingested nutrients and E absent from the faeces have been absorbed
How doed fibre content affect digestibility of feeds?
For every 1% increase in dietary fibre, digestibility decreases by ~1% in ruminants and ~2% in monogastrics
What feed preparation factors affect digestibility?
- Heat treatments
- Cold treatments
- Chemical treatments
How do heat treatments affect digestibility?
Can improve digestibility
- degrades plant cell walls -> increasing nutrient availability
- destroys anti-nutritive factors e.g. toxins
Can decrease digestibility by denaturing proteins
- dependent on wet/dry heat + temperature e.g. dried milk
How does cold treating a feed alter its digestibility?
Can improve digestibility for cattle, pigs and horses
- unnecessary for birds because of their gizzard
- not necessary for sheep with longer rumen retention time
How does chemically treating a feed change its digestibility? How this achieved?
Can increase the digestibility of forage foods with a high lignin content e.g. straw, whole crop silages
Use Naoh or NH3 to promote microbial activity
In what forms can energy be quantified?
As calories
Or Joules
What is the definition of a calorie?
Heat required to warm 1g of H2O from 16.5-17.5ºC at STP
1 calorie = 4.184 J
How is the energy content of feedstuffs determined?
By bomb calorimetry:
- feed samples are dried
- a known quantity of DM is combusted within a sealed chamber
- total E released by oxidation of covalent bonds is determined by the extent of warming of the surrounding H2O
= Gross Energy (MJ/kg DM)
What are example of products of anabolic reactions?
Muscle contractions
Active ion transport
Gene expression
Hormone secretion
Cell division
Adipose reserves
Muscle
What is the 1st Law of Thermodynamics?
Energy can neighter be created nor destroyed, it can only be converted in form
What factors affect Metabolisable Energy?
Diet quality
Species - higher protein intake by carnivores increases their urinary excretion of E-rich N-compounds e.g. urea, creatinine
N-balance - protein deamination or anabolism
What does the Specific Dynamic Action of Feeding refer to?
Heat producing mechanisms including:
- prehension + mastication
- increased gut contractions to propel food
- icreased production and release of digestive enzymes and hormones
- catabolism of nutrients within the gut and tissues
- absorption of nutrients across the gut wall
- heat of fermentation in the rumen and hindgut
What is the metabolic rate of an animal?
Its rate of heat production (MJ/day)
What means are there for measuring the metabolic rate?
Direct calorimetry
Indirect calorimetry
How does indirect calorimetry work?
It estimates heat production by measuring CO2 evolution and O2 consumption rates based on
C6H12O6 + 6O2 -> 6Co2 + 6O2 + 2.82MJ
What is the respiratory quotient (RQ) and what is its significance?
Expired CO2 (L/h)
Inspired O2 (L/h)
RQ allows determination of heat production rates which can be used to define the metabolic rate as MJ/animal/day
What is the basal metabolic rate? How is it measured?
The minimal expenditure of energy required for life
With animals studied in negative E balance, so that E to fuel basal metabolism is derived from body tissues
= fasting catabolism
What does economic maintenance refer to?
Unavoidable movement, feeding and digestion
In the dairy industry, what weight losses are accepted as a normal aspect of their husbandry during milk production?
Losses of 0.5-1.0kg/day
For a racehorse with a heavy workload, what would the energy requirements be?
For a moderate workload of show-jumping, what would the energy requirements be?
For a horse with a light workload in a riding school, what would the energy requirements be?
Maintenance + 100%
Maintenance + 50%
Maintenance + 25%
Approximately how many amino acids are there? How many of these are essential components of animal diets?
About 25 AAs in total
10 essential (15 non-essential)
What is an essential AA?
When tissue synthesis is incapable or unable to meet body requirements when they are absent from the diet.
What is a non-essential AA?
When tissue synthesis is able to compensate for their absence from the diet.
What is the role of Arginine for many species?
Essential for achieving maximum growth rates
Which species has a high dietary requirement for taurine?
Cats
Name the 10 essential AAs.
Arginine Threonine
Lysine Leucine
Isoleucine Tryptophan
Valine Histidine
Methionine
What 3 means are there for evaluatin dietary protein?
- Crude protein
- Digestible crude protein
- Standardised digestible crude protein
What factors need to be considered when evaluating conversion efficiency within animals?
Protein efficiency ratio
Net efficiency retention
Gross protein value
How can protein degradability be measured?
By placing a known quantity of protein into a synthetic mesh bag into the rumen of a fistulated animal
= in sacco evaluation
How long does complete protein degradation take?
Approximately 20hrs
What is effective rumen degradable protein, ERDP?
ERDP = SDP + QDP
What is fermentable metabolisable energy?
The energy sources in the diet that can be fermented by intestinal microorganisms for fuelling host metabolism
When are biological values useful?
BV values are only useful if:
- there is a sufficient E supply to prevent use of protein as an E source ie. carbohydrates, lipids
- protein provision > maintenance
What is RUDP?
Rumen undigestible protein = protein sources presented to abomasum and SI for degradation
What happens if protein degradation occurs too fast in the rumen?
Intestinal microorganisms are unable to capture rapidly produced NH3 -> decreased efficiency of MP synthesis
& wastage of dietary N
What 2 assumptions does the Kjeldahl technique make?
That all food N is in protein
That all food protein contains 160g N/kg DM
What is the empirical formula for carbohydrates?
(CH2O)n when n is 3 or more
Which chemical groups are also classified under carbohydrates?
Alchohols
Ketones
Aldehydes
What are sugars?
Carbohydrates containing lss than 10 monosaccharides residues
Name 3 examples of glucans (polysaccharides).
Starch
Cellulose
Glycogen
How might carbohydrates be stored within the body?
Glycogen stores
Adipose stores
What role does plant cell contents play within the digestive system of a ruminant?
Mammalian enzymes hydrolyse cell contents of sugars and starches -> glucose
Glucose is fermented as FME to yield VFAs
What are the pros and cons of feeding energy dense cereal diets to animals like cattle and sheep?
Pros: provides FME to ruminants and readily assimilated source of glucose to monogastrics → increased productivity
Cons: reduces animal fibre intake + compromises digestive health
What are the indirect nutritional effects of fibre?
Alters behaviour
Alters body composition
Alters milk fat content
Alters H2O intake
What are the two functional classes of vitamins?
H2O-soluble
Lipid-soluble
What is avitaminosis?
Total absence of a vitamin
- results is severe signs of deficiency
What is hypovitaminosis?
Partial lack of a vitamin
- shows non-specific signs of disease
- treat with vitamin supplementation via diet/parenterally
What is the chemical name for vitamin A? What is its inactivated form?
Retinol
ß-carotene
What sources of vitamin A are there?
Plants - grass
Liver
Egg yolk
Milk fat
What are the main signs of vitamin A deficiency?
Night blindness
Cattle - scaly skin → serious risk of infertility, abortion, retained placenta or stillbirths if prolonged
Pigs - eye disorders; weak, dead or deformed litters
Poultry - high mortality rate, retarded growth, ruffled plumage
Dogs - night blindness, abnormal skeletal growth
Horses (rare) - night blindness, hoof splitting
What species can be affected by hypervitaminosis A? What are the potential effects?
Cats and dogs
- abnormal bone deposition
- lameness
- vertebral spondylosis
- gingivitis
- weight loss
- poor coat
Which vitamin is also known as the calciferols?
Vitamin D
What are the functions of vitamin A?
Function and integrity of intestinal mucosa + mm
Bone growth
Humoral immunity
Combines with opsin → rhodopsin for night vision
What are the functions of vitamin D?
Regulates DNA transcription for synthesis of Ca2+ binding protein - increased intestinal mucosa absorption of Ca2+
When hypocalcaemia occurs, hormones promote kidney activation of vitamin D
Stimulates uptake of P from gut
absorption of Ca2+ + P from bone + kidney
What are the signs of vitamin D deficiency?
Disturbed bone growth in young animals
Osteomalacia in adult animals
Calves - weak, bowed or easily broken legs
Poultry - retarded growth; soft, rubbery bones; reduced egg shell quality
Pigs - enlarged joints + stiffness
What is the role of vitamin E? What is its chemical name?
Biological anti-oxidant working against free radicals
a-Tocopherol
What are the signs of vitamin E deficiency?
Nutritional myopathy - generally affects skeletal muscle causing a stilted shaky gait with difficulty standing; cardiac myopathy sometimes seen
Calves - white muscle disease immediately following turnout onto fresh pasture
Lambs - stiff lamb disease immediately following turnout onto fresh pasture
Pigs - cardiac disease seen more often than skeletal muscle weakness
Chicks - nutritional myopathy and brain damage (crazy chick disease)
Horses - lameness and muscle stiffness
Which vitamin deficiency causes crazy chick disease? What is this vitamin’s chemical name?
Vitamin E
a-Tocopherol
What is the vitamin for thiamin?
Vitamin B1
What is the function of vit B1?
Thiamin is involved with initiation and propagation of nervous impulses
Is also a coenzyme within TCA assisting with cellular respiration
What are the signs of thiamin deficiency?
Generically: loss of appetite, emaciation, muscular dysfunction, progressive dysfunction of NS
Pigs - vomit; respiratory disorders
Chicks - polyneuritis; head retraction; paralysis
Ruminants - cerebro-cortical necrosis
What are the clinical signs associated with CCN?
Blindness → incoordination → recumbency → death
Staggering gait
Opisthotonus (severe state of hyperextension + spasticity)
Limb extension/paddling
What would a PM of a case of CCN reveal?
Cerebral oedema
Is cerebro-cortical necrosis treatable? How would it be done?
Thiamin injection
Recovery possible within 24hrs
Which vitamin is riboflavin?
Vit B2
What are the associated signs with vit B2 deficiency?
Pigs - skin eruptions; infertility; abortions; V++; poor appetite and growth; eye abnormalities
Poultry - ‘clubbed down feathers’; ‘curled toe paralysis’ (walk on their hocks with toes clenched)
Young ruminants - inappetant; mouth lesions; D++
What is the chemical name for vit B6?
Pyridoxines
What is the function of the pyridoxines?
Coenzyme in protein and N-pathways
Important for AA absorption from intestines
What is the active form of the pyridoxines?
Pyridoxal phosphate
What are the clinical signs of vit B6 deficiency?
Chicks - neural degeneration and jerky gait
Which of the vitamins is Cyanocobalamin?
Vit B12
What is the biological significance of vit B12?
Important coenzyme for cellular respiratory pathways
Which vitamin is ascorbic acid?
Vit C
What are the functions of Vit C?
Antioxidant
Oxidation and reduction reactions (REDOX)
Normal collagen formation
Fe storage
What are the clinical signs associated with a deficiency in ascorbic acid?
Oedema
Emaciation
D++
Failure of collagen formation → bone + cartilage defects, teeth slackening, CT + muscle weakness, reduced resistance to infection
What mineral is not taken up in cases of enteritis?
Ca2+
When does acute hypocalcaemia most commonly occur and why?
Most commonly seen in female mammals at the onset or peak of lactation
Due to high demands on mammary gland(s) for Ca2+ for milk synthesis
Also seen in laying hens for eggshell production
What is eclampsia?
A condition in which one or more convulsions occur in a pregnant animal suffering from high BP, often followed by a coma and poses a threat to both the dam and offspring.
When does milk fever tend to occur in dairy cows?
Usually 1d before-3d post-partum
What are the clinical signs associated with milk fever?
What is the Tx?
How can this be prevented?
Signs: flaccid paralysis, slow HR, recumbency, rumen stasis, pupil dilation
Tx: IV Ca2+ infusion
Prevention: induce hypocalcaemia prior to calving to promote homestatic Ca2+ mobilisation from skeleton in readiness
What are the clinical signs of eclampsia?
How is it treated?
How can it be prevented?
Signs: spastic paralysis, convulsion
Tx: SC Ca2+ infusion
Prevention: ensure adequate dietary intake + absorption, reduce lactation pressure
What is a pica? Which mineral is it associated with?
Pica refers to an appetite for substances that are non-nutritive such as bone, wood, or soil
It is seen in association with P
Which element decreases absorption of Mg2+?
High Cu intake
In which 4 instances can hypomagnesaemia arise?
- Calves fed all milk diets
- Beef cattle and sheep fed on poor quality roughage or fodder crops
- Lactating cattle and sheep
- Sub-clinical hypomagnesaemia
What is grass staggers?
A disease of livestock caused by Mg2+ deficiency, occurring especially when there is a change from indoor feeding to outdoor grazing
Name 8 trace elements.
Molybdenum
Copper
Seleniumm
Manganese
Iodine
Cobalt
Iron
Zince
What is the importance of Cu?
Essential for immune function
Essential for normal hair and feather pigmentation, and ‘wool crimp’
Vital part of cytochrome oxidase in oxidative phosphorylation
Formation of important plasma proteins
What are the biological functions of Ca2+ in the body?
Dynamic structural component of skeleton
Controls cell excitability - nerve, muscle
Regulates muscle contraction
Regulates blood coagulation
Many enzymatic functions
What are the functions of Mg2+?
Propagates nervous impulses
Most common enzyme activator
Muscle contraction
Does Mg2+ absorption increase or decrease with age?
Decreases
What are the clinical signs for grass staggers? What are these followed by? Which species are commonly affected?
Signs: hyperaesthesia recumbency
incoordination ⇒ convulsions
muscle tremor death
Most commonly seen in sheep + cattle
What is hyperaesthesia?
Excessive physical sensitivity, especially of the skin
What is paresis?
A condition of muscular weakness caused by nerve damage or disease ie. partial paralysis
What is ataxia?
The loss of full control of bodily movements
What happens with swayback in sheep? What is it caused by? What are the clinical signs?
Affects lambs that are born to Cu2+ deficient ewes:
Caused by Cu2+ deficiency
- congenital: stillborns, weak, ataxia and paresis, inability to stand, death
- delayed onset: normal at birth, rapid onset HL weakness, ataxia → paresis + death
What are the signs for copper deficiency in cattle?
Typically occurs from 3-9mo
Signs: ill thrift, poor growth, stiff gait/lameness, loss of hair pigment
What is grass staggers? Which species are affected? What is it caused by? What are the clinical signs?
An emergency condition caused by a deficiency in Mg2+.
It affects in particular lactating cattle + sheep
Signs: hyperaesthesia recumbency
incoordination ⇒ convulsions
muscle tremors death
What 4 situations can hypomagnesaemia arise from?
Calves fed all milk diets
Beef cattle and sheep fed poor quality roughage or fodder crops
Lactating cattle + sheep
Sub-clinical hypomagnesaemia
What conditions arise from acute hypocalcaemia?
Milk fever in dairy cattle
Eclampsia in bitches, sows, and beef cattle
Transit tetany in cattle + horses
What happens to animals if chronic hypocalcaemia occurs?
Growing animals - osteodystrophy + rickets
Adults - osteomalacia; urethral calculi; weak, thin bones; decreased milk yields
What different kinds of stocking are there?
Set stocking - animals left to graze pasture until autumn
Paddock system - crop rotations
Strip grazing - intensive grazing over restricted area
Zero grazing
How many times per year is grass normally cut for making silage?
Roughly 3x
What happens to hay once its cut?
Left to dry from 3-4d + is turned over - to absorb moisture
Baled
Describe haylage. How is it produced?
Very palatable roughage
Contains fewer spores and dust than hay
Left for a day once cut, then baled + bagged to be airtight - retains moisture better
Describe grass silage.
Grass is cut
All air is removed and grass wrapped in black baling, silage clamps used to remove as much air as possible - prevents mould + clostridial succession
Anaerobic bacteria ferment silage - raising temperature
Describe dried grass.
Mainly used for horses + rabbits
eC.g. grass or alfalfa (lucerne)
Slow (100ºC) or fast (1000ºC) air-dried
Good way to promote feeding to prevent gut stasis
Name 3 plants that are harmful to livestock if consumed.
Ragwort - kills horses, dangerous to cattle, sheep, pigs + goats
Acorn poisoning
Rhodedendrum poisoning in sheep
What do straights refer to?
Energy concentrates
Protein concentrates
Name some examples of energy concentrates.
Cereal grains
Cereal by-products
Brewery by-products
Molasses
Beet pulps
Roots + tubers
Maize silage
Animal + vegetable fats
Whey
What means of coll treatment are there for cereal processing?
Rolling
Crushing
Grinding - important for poultry and pigs
How can cereals be processed with hot treatments?
Steam flaking
Micronisation
Roasting
Hot pelleting
Why do horses required their feeds to be processed?
For maximising pre-caecal digestion
What kinds of whole crop silages are there?
Maize silage
Barley silage
Pea/wheat silage
What kinds of chemical treatment are there for processing feeds?
NaoH - softens hull to expose endosperm
NH3 - increase CP + softens grain
Mineralisation
What nutritional benefit do straws offer. Give some examples.
High fibre content - mostly lignin
Low cost roughage
Can be degraded by NH3 to give further nutrients = silage
Barley > wheat > oat
What is the benefit of feeding sugar beet pulp?
Dried form as shreds or pellets - has to be soaked first
Excellent source of energy + fibre
What is the nutritional benefit offered by feeding molasses? Give 2 examples.
Highly palatable feed
Good E provision
Binding agent - making feeds taste better
E.g. cane, beet
What nutritional benefit is offered by roots and tubers?
Grown for both animal and human feed
e.g. turnips, swedes, fodder beet, potatoes
State 6 examples of protein concentrates.
Oilseeds
Leguminous seeds
Animal protein concentrates
Milk products
Single cell proteins
NPN compounds
What nutritional benefit is offered by feeding oilseeds?
Protein-rich cakes + meals
e.g. soa bean, rapeseed, sunflower
What benefit is gained from planting legumes?
Fixing of soil N2
e.g. clovers, peas, beans, lupins
What are some of the potential risks associated with feeding of animal proteins to livestock?
Salmonella
Yellow scrapie
BSE
What is meant by non-protein N-sources?
Ruminants - increased microbial protein synthesis
e.g. urea/NH3-treated forages or cereal grains
direct inclusion of urea - source of FME
What different kinds of additives are there for feeds?
Medicated - antibiotics, coccidiostats, (growth promoters)
* require a prescription
Vits + min supplements
Neutraceuticals (foods believed to have curative properties)
Probiotics
What is a probiotic?
A food or dietary supplement containing ‘beneficial’ bacteria
Define a prebiotic.
A non-digestible foor ingredient that promotes the growth of beneficial microorganisms within the intestine.
What are the different estimations for appetite as a percentage of BW in the main domestic species?
Cattle ~3% BW as DM
Sheep ~4% BW as DM
Horses ~1.5-3% as DM
Pigs ~10% at 2-3wo → 4% BW at maturity
