Semester 2 Flashcards
Types of poultry
Broiler
Broiler / Layer Breeder
Layer
Point of lay
Age when the chicken first starts to lay eggs
Depends on breed but usually between 16-24 weeks old
Pullets
Female bird <1yr old
Layer
Chicken bred for laying eggs
Brooder
A contained area providing warmth (heat lamps) and safe environment for chicks
Hen
Female bird >1yr old
Nutrition of the small holder animal
- less about food production and cost*
But generally very balanced with welfare
Less interested in balancing inputs with outputs
But cost is often an issue
Marketing of feed companies also plays a large role in diet choice
Need to relate to animal physiology and anatomy
So can advise on appropriate fees management
Why quantities are important
Onset of lay requires a dramatic increase in feed consumption
Prior to laying she eats 80g/ day
At point of lay the client needs to increase this to around 100-120g per day
If not eating well, pullet / hen won’t lay eggs
Birds continue to grow until around 30 weeks of age (max body weight) as well as produce eggs
Specific micronutrients
Vitamins supplied as Premix and supplements
A premix is a mixture of vitamins, trace minerals, medicaments, feed supplements and diluents.
It is a value added solution for feeds with sustainable safety and quality.
Specific micronutrients
Egg production varies: according to the breed, expect around 5 eggs per week for 1st 2 years
Number will gradually decline as bird ages - dependant on breed and diet, 1-2 eggs per week when 7-8yrs old
Chickens eat once laid egg > after few hours of eating, next egg started to be produced
Shell forms last and needs stillness (overnight quiet)
Advising grit for healthy gizzards
Chickens pick up grit whilst foraging
Used in gizzard to grind food (no teeth)
If chickens = free range then unnecessary
Advise flint or insoluble grit if can’t forage naturally
Mechanical function only
Egg quality can be nutritionally damaged
Calcium and phosphorus are important
Need 3-5g calcium per day
As hens age they produce bigger eggs > they are trying to lay a clutch of eggs to hatch > in the wild, hens would lay 12 eggs and then stop
Commercial layer may lay clutches of 60 eggs > one day at a time > short rest periods in between
Check the label > layers need 3-5g calcium a day
Layers mash typically contain 2.5% to 3.5% calcium
25g calcium in 1kg of mash
eating 100g mash obtains 2.5g ca, eating 120g mash obtains 3G ca
Nah need additional oyster grit or limestone
Laying hens have a high demand for ca, especially during peak egg production
Calcium metabolism is also under strain in the later stages of egg production, when hens have a decrease in ca absorption efficiency
Growing chickens only need 1.2% calcium in their feed
How much calcium?
Controversy
Layers fed ca deficient diets increase ca absorption levels
High dietary levels of ca reduces its absorption
Ca requirements of 3.25% for laying hens eating 100g per day (NRC 1994)
Indication that older hens need > calcium
BUT, excess of dietary calcium has a negative effect on egg production and reduces feed intake
How much calcium?
Controversy
Smallholders will often keep hens for longer
Older hens less able to absorb calcium > due to reduced intestinal ca uptake and increased egg size?
Increase dietary ca levels from 3.5% to 4.7%
Cracked eggs linearly reduced (p<0.01) from 3.6% to 2.1%
Calcium requirement for aged brown layers up to 4.1% at a feed intake of 110 g/d
Egg size
Every time hen stops laying eggs , then subsequent egg of each clutch is bigger than previous
Longer rest > shorter clutches, bigger eggs and greater ca requirement
Gut becomes lazy in calcium uptake, similar to ‘dry’ cow
Produce same amount of shell regardless of egg size
Egg weight is correlated with body weight of laying hens > lysine required per day by a white egg laying hen is 690mg or 0.69g
Water - the forgotten nutrient
Consume twice as much water as feed (measured by weight)
Many chemical reactions necessary in the processes of digestion and nutrient absorption only happen properly with water
Water softens feed in the crop to prepare it for grinding in the gizzard
An inadequate water supply can cause serious health and welfare problems for the chicken very quickly
Practical feed management - prevent obesity > advice to clients
Kitchen scraps can be harmful to birds causing sour crop and diarrhoea (also illegal)
Always advise feeding birds from a feeder and not on the ground or out in the run
Feeding birds outside attracts wild birds and rodents, potential carriers of disease
Advise not changing birds diet or the brand of feed suddenly
Can cause digestive upset in the bird and be the cause of diarrhoea
Helping clients recognise weight issues in their chickens
Feel for muscle not fat!
Are they feeding them properly?
A good indicator
Size of the UK pig industry
470,000 breeding sows
Producing just over nine million pigs per year
Approx 92% of pigs are kept on 1400 modern commercial farms
Rest on 10 000 small holdings and farms > 720 000 pigs
Pregnancy of pigs
Pigs are pregnant for 3 months, 3 weeks and 3 days on average
112-115 days
A female pig is called a gilt from birth through to when she has a litter (farrowing) then she is called a sow
Stages of pig production
Breeding
Gestation
Farrowing
Weaning
Nursery
Feeder
Grow / finishing
Feeder / market hog
Replacement
Other pig terms
Feeder pig around 25kg > usually 6-12 weeks old that is purchased to raise (feed) to slaughter
With this meat, you could fill your freezer and have enough pork to feed you and your family over until the next year!
Stores 10-12 weeks old > needs finishing to be ready for slaughter
Market hog around 115kg - end product for slaughter
Need to feed to gain nearly 100kg by 6 months > will gain weight at 0.5/0.7 kg per day
Pig terms
Porker 60kg - a pic reared to pork weight, normally about 60kg. Usually achieved between 4-6 months of age
Cutter (good pork meat cuts) 80kg - a pig between pork and bacon weight, raised to produce larger joints
Baconers 80-140kg - a pig being reared for bacon rather than pork
A pigs growth cycle
Surprisingly short.
Antibiotics can promote even faster growth in livestock using less feed because the drugs are thought to enhance the absorption of nutrients.
Many public health officials worry the routine use of antibiotics breeds drug resistant bacteria that contaminate meat
Aims of nutrition for pigs at different stages of production
Gilt rearer > ensure lifetime productivity by focusing on lean growth, bone development and feet
Gestating sow > rebuild and maintain body reserves, support the growing litter and mammary gland development
Lactating sow > maximise milk production and reduce the loss of sow body reserves
Piglet > initiate early feed intake and promote gut development ready for weaning
Weaner > help the piglet overcome the stress of weaning and promote gut development
Grower > promote efficient, cost effective growth
Finisher > produce lean, uniform meat, avoid excess fat deposition
What are sow nuts?
A high quality, versatile 17% protein compounds feed designed for feeding to breeding pigs at ALL stages of the breeding cycle
Colostrum
After farrowing, the sow should be checked to ensure that she has adequate milk supply and that piglets are nursing
It is critical that piglets consume adequate amounts of colostrum within the first 12 hours after birth
Small, weak piglets can be easily crushed by the sow
Intake increased as grower pig gets heavier
Remember feed intake is correlated to body weight
They need space and exercise
Guide to pig feed consumption
1 sow would eat 1.3t of feed per year
1 weaner /feeder from 5-30kg would eat approx 40kg of feed
1 porker from 5-65kg would eat approx 100kg of feed
1 cutter from 4-75kg would eat approx 135kg of feed
Minerals - need a balanced diet with correct levels of vitamins and minerals
Calcium, phosphorous and salt (sodium and chlorine) are the most important major minerals added to swine rations
Minor minerals which require attention are: iron, zinc, iodine, selenium, copper and manganese
Iron> pigs that don’t have access to clean soil should be given supplemental iron, either orally or by injection at 24 hours to 3 days of age or according to the instructions for the products
The main nutrient NOT adequately available in the sows milk is iron
Vitamins - pigs
Vitamins are required in small amounts and are essential for normal bodily functions
Young grasses or legumes are good sources
When swines don’t have access to good quality pasture, vitamin levels of the ration are of greater concern
Vitamins most often added to swine rations are A,D,E,K,B12, riboflavin, niacin, pantothenic acid and choline
The gestating sow should be receiving at least 7200 international units IU of vitamin A or beta carotene and 360 IU of vitamin D per day
Feeding fibre to pigs = beneficial
Dietary fibre, usually defined as the indigestible portion of food derived from plants, forms a key component of many pigs diets
Inclusion of dietary fibre can alter the gut microbiota in ways that could reduce the need for antibiotics
Using crude fibre concentrates as functional feed additives can improve young pig growth and welfare
High fibre diets are used to improve the reproductive efficiency of pigs
BUT the addition of fibre can reduce feed intake which is clearly detrimental during stages of the production cycle when nutrient needs are high > for example in growing piglets and during lactation
Feeing fibre in pigs
Increased resting activity and less stereotypic behaviour and aggression
Increased gut fill and more constant nutrient uptake providing satiety and resulting in reduced constipation, twisted gut, MMA and udder oedema
Improved gut development resulting in increased lactation feed intake and improved microbial balance (prebiotic effect)
Improved colostrum quality
Feeding management - pigs
All feed should be cleared up within 20-30 mins
If food is NOT finished recommend > reduce the amount then increase gradually as appetite increases
Rule of the thumb> 450g-0.5kg of food per day per month age up to maximum of 2.75kg per day
Recommend > if reasonably dry, scattering the pellets on the ground makes feed time last longer
Trough feeding > provide enough space for all the pigs to feed
Feeding management pigs
Pigs are usually fed twice a day
They appreciate routine
Gilts > need around 2.5kg sow breeder pencils
3 weeks before serving increase to 4kg
Gestation back to around 2.4kg
Lactation about 3kg and 0.5kg per day per piglet
Once she is dry (piglets weaned) reduce to 1.5kg
Water is always available
Shelter from sun and rain
Nutrition
Nutrition is the interaction between food / nutrients and the body
Nutrient is a Chemical component that plays a specific structural or functional activity in the body
Food / diet > anything edible / everything that an animal eats
Ration / meal > sequence and quantity of food
Feeding management > eating patterns of individual animals or herds on a daily basis
What are nutrients?
Building blocks of life
Six major classes of nutrients
- Proteins > food sources of protein > amino acids > proteins > muscles, hormones
- Fats / oils > fatty acids and glycerol > lipids > cell membranes, signalling molecules
- Carbohydrates > glucose / volatile fatty acids > glycogen > energy
Important that herbivores obtain up to 100% of their carbohydrates from cellulose found in plants, high in fibre.
Omnivores and carnivores CHO from starch found in seeds/ grains
Micro
4. Vitamins
5. Water > inorganic
- Minerals
Macros > provide nutrients which are used to build tissue
Trace
Animals (humans)
Need protein, carbohydrates, fats, vitamins, minerals and water in our diets
Fat is an energy source > a viral component of cell membranes
Carbohydrate is an energy source > high sugar diets are bad for us
Protein
Broken down into amino acids and used for structural purposes in the body
Products from food animals provide over 33% of protein consumed in human diets globally and about 16% of food energy
Protein is an essential key ingredient of animal feeds and is absolutely necessary for > animals growth, body / muscle maintenance, the production of young and the output of products as milk, eggs and wool
Nutrients - molecules / chemicals needed for life
Found in food > food ingredients, compounds
How nutritious are they? > nutrient value / energy
How well the animal can eat / digest them
Diet differences
Carnivores consume primarily animal tissue
Herbivores consume primarily plant material
Omnivores consume plant and animal tissue
A question of balance - most feeds provide a mix of nutrients
But the nutrition they provide depends on:
How much the animal eats
The quality of the nutrients
The quality / physical presentation of the food
The animals digestive system
Whether the animal eats the food
What else is being fed
The gut
Site of digestion > maximise nutrient utilisation to reduce substrate for bacteria, support epithelial cell growth and differentiation
Physical barrier > support gut tissue integrity and limit bacterial translocation, prevent adhesion of pathogenic bacteria
Host for microflora > balance microbial populations with low numbers of potentially pathogenic strains
Immune organ > support appropriate immune response, control inflammation
What is the microflora and why is it important?
100 trillion microorganisms live in our bodies and on average 1500 species of micro-organism inhabit the gut of animals and humans
These microbes have numerous beneficial functions relevant to supporting life such as digesting food, preventing disease causing pathogens from invading the body and synthesising essential nutrients and vitamins
What is the micro biome?
For every one host gene, there are 100 associated genes within the micro biome
Good bacteria
Bfidobacteria > the various strains help to regulate levels of other bacteria in the gut, modulate immune responses to invading pathogens, prevent tumour formation and produce vitamins
Escherichia coli > several types inhabit the human gut. They are involved in the production of vitamin K2 (essential for blood clotting) and help to keep bad bacteria in check. But some strains can lead to illness
Lactobacilli > beneficial varieties produce vitamins and nutrients, boost immunity and protect against carcinogens
Bad bacteria
Campylobacter > c jejuni and c coli are the strains most associated with human disease. Infection usually occurs through the ingestion of contaminated food
Enterococcus faecalis > a common cause of post surgical infection
Clostridium difficile > most harmful following a course of antibiotics when it is able to proliferate
Beneficial roles of the normal microflora
Useful for the enzymatic breakdown of feed in ruminants
Certain vitamins or their precursors are synthesised by the normal flora (eg B complex, vitamin K by E. coli and bacteroides fragilis)
By products > butyrate from commensals improves enterocyte health
The normal flora plays a role in controlling the multiplication of pathogens:
Competitive exclusion
Bacteriocins
Immune stimulation
Physical disruption
Role of bacteria in gut health - foregut
The bacteria in the gut breakdown cellulose and use the glucose for their own metabolic needs (fermentation)
As a waste product of fermentation, the bacteria release volatile fatty acids VFAs (eg acetate, butyrate, propionate) which the animal utilises for energy
Role of bacteria in gut health - hind gut
Bacteria ferment carbohydrates into short chain fatty acids SCFA
Bacteria convert dietary and endogenous nitrogenous compounds into ammonia and microbial protein and synthesise B vitamins
Absorption of SCFA provides energy for the gut epithelial cells and plays an important role in the absorption of Na and water
Next generation sequencing > community analysis
Sequencing is used to identify all the organisms in a sample and evaluate their relative proportions
For bacteria the most common protocols involve the amplification of the 16s (18s for fungi etc) of all organisms and then these are sequenced
Shotgun metagenomics
16S rRNA NGS and metagenomic studies
Universal PCR for 16S rRNA genes
High throughput sequencing
Analysis on QIIME for taxonomic assignment > identify 15,000 species per sample, >500 genera identified
Artificial gut systems for studying the microflora
Development of the equine hind gut model
Transmission of AMR in the chicken gut
Understanding the role of diet in metabolic disease
Summary - gut
The microflora influences health and disease
Understanding the make up of the microflora can provide a detailed understanding of the pathobiology of diseases
The microflora is influenced by intrinsic and extrinsic factors
What are food additives?
Feed additives are products used in animal nutrition for improving the quality of feed and the quality of food from animal origin
To improve animals performance and health eg. Providing enhanced digest ability of the feed materials
Why are anti microbials important in livestock nutrition?
Improve feed conversion ratios
Improve quality of meat / milk / eggs
Reduce incidence of disease > huge economic benefit
Problems with the use of antimicrobials in livestock
Development of antimicrobial resistance thus compromising therapeutic treatments
Resistant bacteria may be transferred to humans, where they may be difficult to treat
Pathogens remain on farms for many years as the antimicrobials mask clinical disease
Antimicrobials may make animals susceptible to other pathogens
History of growth promoting antibiotics
Moore et Al 1946 and stokestad et Al 1949
Poultry
Chickens
Turkeys
Pigs
Jan 2006, ban on all growth promoting antibiotics in animal feed in the EC
Antibiotics still used in animal feed in some countries
Why modulate the microflora?
Livestock often exposed to stressful conditions which can imbalance their micoflora
This results in:
Low weight gain
Respiratory disease
More frequent diarrhoea
High morbidity and mortality rates
Benefits of modulating the microflora
Novel methods of controlling diseases
Reduce pathogen carriage eg. Campylobacter
Improve feed conversion ratios
Improve environmental conditions for animals
Improve welfare standards for animals
Alternative to antimicrobials
How can we modulate the microflora?
Probiotics, prebiotics, synbiotics, postbiotics
Next generation growth promoters
Metals
Phage therapy
Natural plant extracts > phytochemicals
Vaccines
Acidifiers
Enzymes
Faecal transplants
Summary - gut microflora
The microflora influences health and disease
Feed additives can be used to modulate the gut flora
Some feed additives can result in undesirable consequences > antimicrobial resistance
What are prebiotics?
NON digestible (by the host) food ingredients that have a beneficial effect through their selective metabolism in the intestinal tract
Natural compounds found in soybeans, human breast milk, chicory roots and oats
How do prebiotics work?
Unlike probiotics, which are live bacteria or other organisms, prebiotics are carbohydrates that act as food for the food bacteria
Prebiotics are NOT destroyed, digested or absorbed in the upper GI tract and therefore reach the lower intestine where beneficial bacteria reside
Prebiotics provide a natural way of increasing the number and activity of the beneficial bacteria already resident in the colon
Synbiotics are preparations where pre and probiotics are combined and administered together!
Common examples of prebiotics
Galactooligosaccharides GOS
Fructooligosaccharides FOS
Inulin
B1-4 mannobiose
Lactulose
Prebiotics and salmonella
Prebiotics reduce colonisation of salmonella in the mouse
Prebiotics reduce pathology during salmonella infection
Summary - prebiotics
Prebiotics are efficacious at modulating the gut flora
Prebiotics can be used to control livestock and poultry pathogens
Prebiotics are best used in combination with probiotics > synbiotics
What are probiotics?
Live microorganisms which when administered in adequate amounts confer a health benefit to the host
Eg lactobacillus, bifidobacteria, enterocci, streptococcus
How do probiotics work?
Allow out competition of pathogens:
Reducing available receptor sites
Modulating the environment
Modulating pathogen behaviour
Producing antimicrobial compounds
Altering the immune response of the host
Understanding probiotic efficacy
3D cell culture
In vitro organ culture IVOC
MuDPIT proteomics
Metagenomic studies
Efficacy trials
Do probiotics reduce S. Typhimurium induced ruffles?
Membrane ruffling due to salmonella infection
Loss of microvilli and damage to the cells due to bacterial invasion
Probiotic modulation of the pathogen > salmonella Typhimurium
Synthesis of new proteins:
1. Up regulation of TCA - dicarboxylic acid intermediates
2. Increased expression of ribosomal sub units
3. Elevated levels of chaperonins and HSPs
Limited ATR:
1. Up regulation of lysine de carboxylase
2. Synthesis of cyclopropyl fatty acids
Induction of PEP glyoxylate pathway?
Summary - probiotics
Probiotics are efficacious at modulating the gut flora
Probiotics can be used to control pathogens in livestock
Probiotics are best used with prebiotics > synbiotics
Assessment of the diet > simple collection data and observation
- Type of food > forage, energy sources, supplements, raw, tinned, dry biscuits
- Amount of food > weight in kg or g, if containers find out what weight they contain
- Feeding management > how often, in groups, individually, herd level
What do you think of this forage?
Collect the clues
Do you know what it is
Is it suitable for the animal
Can you recognise its feed value
How will you respond
Will it be safe to feed
Are they feeding it correctly
Forage
Clue 1
Is it plant material / feed (leaves and stems) > eaten by grazing or browsing animals, forage crops
Provide 50-100% of all the total fees requirements of ruminants / herbivores
Typically grass
Pasture
Clue 2
Provides sufficient quantity and quality of forage to sustain a particular group of livestock and generate profit for the farmer
A major renewable natural resource with significant ecosystem:
Diverse plant communities provide different nutrients (carbohydrates, proteins, minerals) and plant secondary compounds (PSC eg. Condensed tannins, terpenes) which attract and provide food for pollinators and seed dispensers
Forages
Clue 3
Does it contain fibre?
Yes! All forages contain fibre, a source of carbohydrates
Main CHO found in forages is fibre > cellulose, hemicellulose, lignin, found in plant cell wall NOT cell contents
Herbivores > need a large % of cell walls to maintain physiological and psychological health
Fibre = plant cell wall carbohydrates
As plants become more upright their stems stiffen because they contain more lignin and less cell contents
Lignin
Clue 4 - how long has it been growing
Major component of the cell wall of older (mature / late cut) forages
Plant matures, lignin content increases
Grasses and crops accumulate lignin in their stems as they mature
Means they can stand upright and support seed heads
Lignin / limits digestion of plant polysaccharides
Digestion is limited when high lignin > plant ages = shift in the type of lignin being deposited
Lignin cross links to the polysaccharides of the plant cell wall (mainly hemicellulose), digestion is dramatically decreased
Determining factor for digest ability
Cross link forms a barrier that limits microbial access to polysaccharides so can’t ferment the fibre
Summarise the clues - fibre is a:
Carbohydrate
Found in plant cell walls
Polysaccharide > cellulose > hemi cellulose > lignin
Cellulose = found only in plants, forms cell walls and gives them their rigidity. Contains inter molecular hydrogen bonds and is an insoluble fibre
Structural
Can’t be digested by mammalian enzymes
Fermented
Choosing which forage / explaining to the client
What effects the digest ability / feed value of forage?
- Feed availability / seasonality
- Species
- Growth stage
Digestibility > d value, how much feed value / nutrition the animal can get from the forage
Collect evidence to find out how nutritious is the forage
- Availability
Clue 5- herbage mass
Seasonal variation - climate dependant
Little growth in winter
Most abundant in spring
Summer dependent upon rainfall
Declining through autumn
Forage availability
Management dependant - stocking levels
Balance between animals grazing and grass growth
Requires grass management > rotation, fertilisers, harvesting excess
Pasture / forages need managing
Leaf selected in preference to stem
Over grazed, whole plant denunded > cannot photosynthesis
Roots depleted
Bare paddocks
- Species
Clue 6- what type of grass is growing
Persistency, productivity and nutritive value
Perennial ryegrass, Timothy, fescues, coltsfoot, clover
Check ‘what’s that feed’ > reference in nutrition practical folder!
- Growth stage
Clue 7- how old is the grass?
Young grass > highly digestible
Older grass > less digestible
Digestibility dependant upon > lignin content, ratio of cell wall to cell contents, type of fibre
Feed value = combination of several factors
Availability
Digestibility
Young grass < herbage mass
Older grass < herbage mass
Now you have collected the clues, you can use the evidence to:
Describe a forage
Define fibre
List the effect of age on fibre content of the forage
Describe what effects the Digestibility / feed value of forages
And advise which forage to feed!
‘Is this the right forage?’
Do you know what it is
Is it suitable for the animal
Can you recognise its feed value
How will you respond
Will it be safe to feed
Are they feeding it correctly
Preservation for when fodder / fresh forage / grass is scarce
Maintain optimum nutrient value of grass (fodder)
Move feed from field to parlour / stable / yard or winter pasture
Assist pasture management > forage is the foundation of herbivore diets > forage first and foremost!
Method of conservation
Natural fermentation / pickle > high moisture
Drying > low moisture
Need to conserve! Grass does not grow all year round
Fermentation clue 1- has it been fermented > how do you know?
Silage = fermented young grass
iPad
The picking process
Anaerobic - excludes oxygen
Lactic acid bacteria multiply and grow
Use the sugars in the grass > convert to Lactic acid and other VFAs
As environment acidifies > stops plant enzymes, stops degrading bacteria
When ph 3-4 inhibits lactic acid bacteria > crucial, too high ph = secondary fermentation, too low ph = unpalatable
Preserves forage / crop
Fermented older grass
Haylage for horses
Clue - when was it cut? How dry is it?
iPad
Drying forages
Clue - has it been dried? How do you know?
Grass is dried to preserve as hay
Clue - is it stored under cover? Is it wrapped or not?
iPad
Straw by product of cereal harvest,
Not grass
Clue - it it straw?
iPad
Drying
Can dry most plants
Grasses
Cereals > whole crop, straw
Legumes > alfalfa (not grass)
Can be pelleted
Fibre presentation - other sources
Root vegetables
Sugar beet > whole crop, pelleted / shredded
Turnips etc > harvested, fed in field
Fermenting vs drying
It’s all to do with water
iPad
Forages - feel it, smell it, find it
What do they make
Where is it stored
What does it look / smell like
How much is fed
What animals is it fed to?
Self assess your understanding > talk to the farmer / owner / staff > bring the theory to life
Summarise the clues (forage)
Is it dry or fermented > how much water does it contain
Is it cut from young or older grass or a by product of cereal harvest > is it grass, what species of grass
Is it high or lower in feed value
How is it stored > indoors or wrapped, why it it stored this way
Cereals
Clue - what are cereals?
Cereals or cereal grains
Edible seeds of specific grasses
Plants belonging to the gramineous family
Grains that are used for food, feed, seed (FAO)
Cereals
Clue - why are they fed?
Storage carbohydrate
Polysaccharide
Starch
Energy
Enzymatic breakdown in small intestine
Storage vs structural carbohydrates
Simple link changes the role / function
Cellulose (fibre) > beta 1-4 glucose links, fermentation by bacteria, structural
Starch > alpha 1-4 glucose links, digestion by mammalian enzymes, storage
How nutritious is the cereal, what is its Digestibility?
Dependent on a number of plant and animal factors
A. Variety
B. Method of processing
C. Digestive anatomy of the animal
Variety of cereals
Analysis varies
Do all cereals have the same nutrition?
iPad
Processing cereals
Are the cereals whole or have the been physically changed?
Whole cereals > most Suitable for acidic stomachs, animals that can chew
Horses chew feed to 1.6mm before swallowing, depends upon fibre level and kernel hardness
Physically / mechanical processing > breaks open the kernel, potential oxidation
Grinding breaks the pericap, increases the surface area of the Material, more exposure to the microbial enzymes, quicker fermentation, breaks open cell walls for enzymic digestion in animals that don’t chew
Cooking / manufacturing cereals
How has it been cooked?
What does cooking do?
Which animals is this relevant for? Think digestion
Micronising
Steam flaked
Extruded
Gelatinised starch > increases small intestine digestion, breaks structure of starch and exposes greater area to enzymes
Animal species - cereal
Does the animal need cereals?
Herbivores forages / Fibre first > cereals / compounds additional energy for production / performance animals
Carnivores meat or meat derivatives first > cereals / compounds are additional energy for production / performance animals
Not ideal for cats which are obligate carnivores, fibre needed for gut health (but not forage)
Omnivores cereals main bulk of diet > fibre supplied as whole grain cereals > fibre needed to maintain gut epithelial health and gut peristalsis
Compound feeds
Mixture / formulation of feed ingredients
Complete feeds and complementary feeds
Made to a known recipe
Complete vs complementary compound feeds
Complete > formulated to meet the Ann and daily nutrient requirements when fed at the recommended rate > is the sole constituent of the diet > feeding other foods alongside unbalanced the scientific formulation
Provides total intake and diet is balanced
Balances deficiencies in forage or other ingredients: energy, sometimes protein, added micronutrients
Complete feedstuffs
Pet foods > mix of cereals, meats and meat derivatives and vitamins and minerals
What about tinned and pouches
Check the feeding guide
Complementary feed stuffs
Pets > BARF
Herbivores > balance deficiencies in forage, energy, protein, micronutrients, usually lower intakes / kg per BW compared to complete
Manufactured feeds - is it the right feed?
What does the label say?
A. Species - anatomy
B. To be fed with what
C. What lifestage
D. How much should be fed
E. Does it suit the animals gut
Species - had the client picked the correct feed
Front of packaging
Statuary statement - label or back of the bag
What should it be fed with?
Check the feeding advice
Forages vary in nutritional value
Grass > spring vs autumn vs summer vs winter > quality and quantity
Preserved > species and quality of preservation
Hay vs haylage
Silage vs baleage (cows)
Straw
Lifestage
What life stage and workload is it suitable for
Different requirements and I takes according to aged and production
Light work / leisure
Reproduction
Performance / work - horses, meat, growth
How much should the be feeding?
Look on the bag / label
Feed formulated to meet energy and appetite requirements
iPad
Assessment of the healthy animal
- Weight
- Work load
- Fat score (condition score)
- Age
Systematic collection of animal info
Electronically
Paper
Legal requirement in farm animals
Part of environmental and health audit
One of the 5 freedoms
Can you find examples of diet collection sheets? What would you include?
Body weight
Primary importance for knowing how much an animal can physically eat
Bodyweight - feed intake is based on body weight
Animals eat to meet their appetite requirements, when food is abundant they eat as much as possible and store as body fat when food is scarce
All animals eat to obtain calories
Main driver for intake
Controls metabolism > insulin resistance > normal response to decrease in calories
Can they eat enough food to consume calories for maintenance? Actually normally in excess
But can be a challenge for hard work / production
Body size patterns explanation
Digestibility and rate of passage through gut of the diet is dependant upon gut volume and food intake
Gut volume is a constant proportion of body weight
Also depends upon the type of food eaten
The principal determinant of rumen capacity (fibre digestion) is the size of the animal
How much can herbivore animals eat?
Most herbivore animals can consume the equivalent of between 2-4% of their body weight as nutrients (DM)
So calculate intake in dry matter (DM) as a % of body weight (BW)
So measure body weight and multiply BW by the % that should / can eat
How to work out how much animal can eat
Total nutrients (dry matter) can eat is 2.5% bodyweight for example=
(BW x 2.5) / 100
Example: a 500kg horse can eat 2.5-4% of their BW
(500x2.5) / 100 = 12.5kg DM
And
(500x4) / 100 = 20kg DM
Dry matter intake (DMI) = 12.5-20kg DM
Intake capacity
Appetite / intake can be restricted by bulk a dry matter capacity > if low nutrient value cannot eat enough
How to obtain accurate body weights
Most accurate is a weigh bridge
Every visit to the vet should plot weight changes and tell the client
Use of weigh tapes for horses and cattle > use of height specific weigh tapes can provide a more accurate estimate of equine body weight
Weighing the animal
Owner should weigh
Regularly
Same time of day
Same place on body
Note it down
Show them how, do not assume
Small animals > individual weights
Herds / flocks > average of a specific number
Should we just weigh them?
There are limitations of using body weight as a predictor of health
Can body weight predict body composition? What about body mass index BMI?
Body weight is a relatively poor indicator of health and nutritional status > body composition is more important
Know the components that comprise an individuals body weight
Measure:
Fat mass (FM) and fat free mass (FFM)
Two compartment model
Fat vs muscle
Muscle weighs more than fat?
Beware of misconceptions
Different tissues > cannot convert one to the other!
Measuring body composition to check calorie consumption - what is fat condition scoring?
Manual palpation of the fat cover over predetermined, scientifically validated areas of an animals skeleton
Semi objective
A score is allocated according to a descriptor of what you are feeling > specific charts for each species
Depends upon expertise of scorer > not dependent on breed
Dairy cow - what clues can feeling for fat provide?
Assessment of feed intake > variation across herd, investigate space and adequacy of feed
General health > dentition and locomotion
Economics > predictor of future performance, milk yield, fertility etc
Lower calving BCS > reduced production and reproduction
High calving BCS > reduction in dry matter intake during early lactation > reduced milk production and increased risk of metabolic disorder
Is a system that measures body fat with 95% confidence to + or - 10% sufficiently adequate to be clinically useful?
Is body condition scoring worth doing?
Body condition scoring is generally independent of weight or frame size, indicating that additional info is gained from BCS
Good enough to be used to place animals in thin, average and overweight categories
Useful in convincing clients that their pet or animals in their herd or flock need to be fed more, less or differently from the manner that is currently being used
Body condition / fat scoring
It is easy
Documented that body condition scoring is reliable > performed in accordance with specific protocols > conveys useful clinical info
IF it is done properly
Tip to help owners understand body fat
See and feel bones: not enough fat cover , < 2.5 anywhere on body
Feel but not see bones: ideal fat cover = 3 anywhere on body
Can’t see, can’t feel: excessive fat cover= > 3.5 on the body
Bone as a calcium reservoir
Main reservoir for calcium
99% of the body’s 1000g of calcium found in Skeleton
Bone mineral is 99% hydroxyapatite > Ca10(PO4)6(OH)2
Bone mineral consists primarily of calcium and inorganic phosphate
What is the primary purpose of the skeleton?
Abundant calcium supply > Need to protect cells from excess
Intermittent calcium supply > need to maintain homeostasis
Skelton primarily a reservoir for calcium and base > skeletal integrity is compromised to preserve homeostasis
But… structural function of skeleton also conferred evolutionary advantage of locomotion
Summary of functions of the skeleton
Support
Protection
Movement
Mineral reservoir
Buffering against acidosis
Blood cell production
Trabecular bond
Is very metabolically active
Bones grow, adapt and repair itself
Bone constantly being formed and degraded > bone turnover
This allows growth, adaptation to loading and repair to occur
Provides mechanism by which circulating Ca can be regulated
Bone remodelling
Resorption > osteoclasts break down bone creating a resorption cavity
Formation > osteoblasts make new nine matrix which is then mineralised, filling the remodelling space
Enables bone to: adapt to mechanical loading, repair damage, regulate circulating Ca levels, contribute to acid / base balance
Bone resorption and formation are normally coupled = bone remodelling
Functions of calcium
Membrane and cytoskeletal functions
Neural transmission
Cell signalling
Bone mineralisation
Enzyme Co factors
Blood coagulation
Muscle function
Calcium homeostasis
Serum calcium levels are tightly controlled
Serum calcium maintained between 8.5-10.5 mg/100ml
50% ionised Ca2+
50% bound eg. To albumin or complexed : eg. With bicarbonate, citrate, phosphate
Calcium homeostasis
Main organs:
Skeleton, kidney, GI tract
Main hormones:
PTH - parathyroid hormone
1,25 (OH)2D - active vitamin D
Calcitonin
Calcium and bone cells
Bone resorption > PTH and active vitamin D activate osteoclasts
Osteoclasts secrete enzymes which degrade bone matrix
Ca2+ and Pi released
Bone formation> osteoblasts secrete collagen and matrix proteins
Mineralise new bone with the formation of Ca10(PO4)6(OH)2
PTH inhibits bone formation
Skeletal integrity vs calcium homeostasis
The skeleton is a reservoir for calcium
Low serum calcium eg. Diet, growth, pregnancy, lactation > results in rapid metabolic responses to restore calcium balance
Mostly at the expense of the skeleton!
Lactation in cows
Calcium requirement increases 4-5x relative to late gestation > a cow producing 40L milk per day requires an extra 80mg Ca per day
Maintaining homeostasis is a major challenge
Normal adaption in cow - calcium homeostasis
Decrease in serum calcium
Increase in PTH secretion, vitamin D activation, absorption from gut, bone resorption
In the first month of lactation a cow will lose 9-13% of her bone calcium to maintain homeostasis whilst providing for her calf
As with humans this bone loss is temporary > normal adaptation
What happens if this normal adaptation to calcium is impaired in cows?
Periparturoent hypocalcaemia - milk fever
Severe hypocalcaemia > serum calcium <8mg / dL
Symptoms of milk fever:
Early stage > muscle tremors, stiff legs, restlessness
Progression > muscle weakness, lying down, head against chest, gut stasis
Severe > lying on side, coma, death due to paralysis of respiratory muscle dagger 12-24 hrs
Nearly 25% of cows will have serum calcium levels less than 8mg/Sal 12-24hr after calving, and 5% will develop milk fever > 5.5-8.5 mg/dL
Feeding cows inorganic acids like HCL or H2SO4 peripartum will significantly reduce the incidence of milk fever
Fruit and vegetables for bone health
Vitamins > B6, B12, C, B carotene, folic acid
Organic anions > citrate, malate > bicarbonate which goes to potassium citrate and bicarbonate
Minerals > K, Mg, Zn
Flavonoids and phenolic acids
Short or long term supplementation with KHCO3 and Kcit > reduced calcium loss and reduced acid excretion
Reduced bone resorption > preserves bone
Alkaline potassium salts are abundant in fruits and vegetables and could provide an additional dietary means of attenuating age related bone loss and preventing osteoporosis
Bone and acid base metabolism
Acid base homeostasis is tightly controlled (ph 7.35-7.45) by buffering systems:
Lungs excrete co2, kidney excretes H+ and reabsorbs HC03, plasma proteins act as buffers
If acid load exceeds capacity of these systems > H+ increases and C03 decreases > metabolic acidosis
Bone resorption releases bone mineral providing bicarbonate to neutralise the excess acid. Calcium is excreted and bone weakened.
This is partly mediated by changes in the PTH receptor > tissues become more responsive to PTH
Acid base balance, hypocalcaemia and Enders observations
His proposal > failure of adaptation to hypocalcaemia due to imbalances of anions and cations
Dietary Cation Anion Balance Equation:
(Na+ + K+) - (Cl- + SO42-) meq/kg
Preventing the problem of hypocalcaemia
- Enders dietary cation anion balance (DCAB) equation can be used to manipulate the diet of the cow postpartum to maintain a state of acidosis
Reduce sources of K > alfalfa, clover, many grasses are high in K. Affected by season (mature crops have lower K), fertiliser use
Increase intakes of acid anions Cl- and SO42- > problems: palatability
Monitor urine ph > should be ph6-7 depending on breed - Prepartum reduction of calcium intake
Stimulates PTH secretion and osteoclasts activity so that Ca is released into circulation. Low calcium diet provides <20g ca/day. But need to switch to high Ca diet after calving! - Vitamin D supplementation
Problems > timing, toxicity - Increase Mg intake
Mg is required for calcium absorption from the gut, for PTH secretion and as a cofactor for PTH activity. Low mg levels lead to reduced tissue sensitivity for PTH. Mg is poorly absorbed when K intake is high. Mg intake should be 3.5-4g/kg
Summary of milk fever
Milk fever is the result of hypocalcaemia > due to metabolic acidosis and high intake of K or low Mg intake
It can be prevented through:
Dietary acidification by manipulating DCAB, increasing Mg intake / reducing K intake, deceasing Ca intake prepartum
Homeostasis at critical stages such as pregnancy and lactation depends on complex interactions of micronutrients among themselves and with other systems and the ability of these systems to adapt!
Changes in any one part of the system affect all the other parts!
Minerals
Top tip > blood analysis is a poor indicator of an animals mineral status
Think about homeostasis!
Challenges in establishing requirements for micronutrients
Interactions
Species
Feedstuffs
Deficiency vs imbalance > when are the clinical signs?
Deficiencies are rare > over fed but undernourished, organic systems
Overview of macro minerals
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Overview of macro minerals - role in dairy cows?
Think about the ratio with Ca
High in forages > challenge to reduce around milking time
Role in cow and sheep nutrition
Think about cell transport > why might it need supplementing?
Trace elements (copper, iodine, iron, zinc, selenium and cobalt)
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Common mineral scenarios
Horses low in salt 2 teaspoons per day > pasture and hay reflect underlying soil nutrients
Sheep > excess copper if fed with horses
All ruminants > molybdenum stops Cooper being absorbed, iron antagonist for copper
Pastured fed animals > likely to be deficient in a number of minerals
Ca low in forages, specifically straw and hay and grass
Low in cereal grains
Vitamins
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B vitamins in animal nutrition (biotin, folic acid, niacin, d pantothenic acid, thiamine, B2, B6, B12)
Most B vitamins are by products of fermentation in herbivores
Also where SCFAs produced
iPad!
Vitamin A, C, D and E
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Common vitamin deficient scenarios
Vitamin D > reptiles not provided with sunlight, dogs on raw food, horses preserved forages, rugged in winter and not fed, winter feeding cows
Vitamin B > fermentation disrupted, diarrhoea for all animals
Vitamin A > organic cows
Vitamin E > grass excellent source, low in preserved forages, winter deficiencies unless balanced, oilseeds normally good source
Harmful effects of the parasite on the host
Wasting (cachexia)
Superinfections > secondary bacterial infections
Immunosuppression
Production of toxic compounds
Allergic reactions
Anaphylactic shock
Irritative intestinal contractions (Ascaris)
Irritation of skin and tissues by ecto and endoparasites
General effect of gastrointestinal parasites
Decreased feed intake and worsened feed utilisation > decreased average daily gain of growing animals = weight loss > negative energy and protein balance > changes of body composition > reduced percentage of protein in the carcass > decrease of bone density (poor mineralisation) > in growing animals
General effect of gastrointestinal parasites
Anaemia
Change of plasma proteins
Reduced albumin
Increased globulin and total protein (mild infection)
Reduced total protein (serous infection)
Infection is also manifested in oedema, diarrhoea, lower blood pepsinogen and change in activity of liver enzymes
General effect of gastrointestinal parasites
Change of body and skeletal composition
Decreased protein and fat content
Decreased calcium and phosphorus concentration of bones by 15-45%
Tissue susceptibility against protein energy malnutrition: wool, fat depots, muscle, blood, liver, spleen, heart, nerves and brain
Decreased length and diameter of wool fibres
Copper deficiency > compromised resistance to internal parasites
Effect of gastrointestinal parasites on gut health
Ulcers and haemorrhages in large intestine > Anaemia
Flattening and atrophy of Villi in small intestine
Hyperplasia and inflammation of mucous membrane
Thickening of intestinal wall
Decline of brush border enzymes in small intestine
Effect of parasites on digestion
Modified gut mobility
Peristalsis generally slows down, unless diarrhoea occurs at the same time
Worms toxins stimulate the production of gastrointestinal hormones like gastrin and cholecystokinin causing reduction in voluntary feed intake
Reduced HCL production
Effects of parasites on digestion
Reduced digestion and absorption of nutrients
Increased endogenous nitrogen excretion
Enhanced protein synthesis in blood and liver to replace the amount of plasma proteins excreted into the gut lumen
Reduced muscle mass
Effect of parasitism on host nutrient utilisation
Reduced nutrient availability through reduction in voluntary feed intake and or reduction in the efficiency of absorbed nutrients
Increased loss of endogenous protein into the GI tract > increased metabolic protein / AA requirement
Effect on GI motility: diarrhoea > loss of plasma protein Na+ and Cl- and increased K+ level
Altered acid base balance
Diversion of nutrients and protein synthesis from production processes such as muscle, bone, wool, milk, egg etc towards repair processes
Effect of parasitism on host energy metabolism
Increased energy (maintenance) requirements due to raised heat (fever)
A 15% rise in metabolic rate and 25% rise in maintenance requirement for every degree rise in body temperature
Reduced digestion of gross energy of complete diet
Infected animals have lower energy retention and impaired efficiency of energy utilisation
Effect of parasitism on host protein metabolism
Reduced N retention is a characteristic feature of gastrointestinal parasites > increased urinary N loss > reduced efficiency of utilisation of absorbed amino acids > high levels of blood protein loss into GI tract in helminth infections > reduced crude protein digest ability in the small intestine > increased plasma loss = increases fecal N loss
Effect of parasitism on host mineral and vitamin metabolism
Decreases in copper uptake and changes in sulphate metabolism
Release of copper and resorption and sequestration of iron and zinc in protein calorie malnutrition, infection and acute starvation
Vitamin A deficiency
Cobalt deficiency may also enhance the susceptibility to disease
Reduced vitamin B12 synthesis
Summary of effects of parasitism on nutrition
Parasites effect the nutritional status of animals:
Reduced feed intake, decreased nutrient absorption, increased nutrient requirements of animals
Parasites effect the energy, protein, vitamin and mineral status of animals
Reduced nutrient intake and absorption is harmful in high stressed animals
The poor nutritional status of an infected animal by parasites contributes to its ability to respond to a microbial disease challenge
Animals infected with parasites have fewer nutrients available for growth and reproduction
Easy to see the outward signs of inflammatory disease
See the bones = too thin
Feel but not see = ideal fat cover = healthy adipose tissue
Neither see nor feel = too fat
Encourage owners to run their hands over their animals Skeleton > what do they feel?
Difficult to recognise inflammatory disease?
One in three pets are overweight
Nine out every ten pet owners were concerned about the weight of their pet
35% of cats are overweight
77% vets believe that pet obesity is on the increase
70% owners feel other problems are more serious then obesity
Toxicology
Check lecture notes
Obesity - an overview
Humans, horses, pets
There is growing recognition that obesity is common and represents a significant detriment to the health of companion animals in a manner similar to that by which it is affecting the human population
The reasons that companion animals develop obesity are similar to humans > lack of exercise and consumption of excess calories
What evidence is there that fat is a health and welfare issue for people and pets?
Long term challenges:
Excess body fat increases the risk of health impairment, ie. A welfare issue
2.1 billion obsess globally - nearly 30% of world population
Obesity is one of the top 3 global social burdens generated by human beings
Current cost of obesity in UK = £47 billion
Responsible for 5% deaths per year
Diseases linked to excess fat in carbs
3.9x more likely to develop diabetes (type 2)
4.9x more likely to develop lameness
2.3x more likely to develop non allergic skin conditions
Fatty liver, urinary tract disease, dermatological conditions, oral disease
Diseases linked to excess fat in dogs
2.6x more likely to develop diabetes (type 1)
2.1x more likely to rupture cruciate ligament
2.8x more likely to develop hypothyroidism
Hyperadrenocorticism, ruptured cruciate ligament, hypothyroidism, lower urinary tract disease, oral disease
Welfare issues associated with long term, low grade inflammatory disease - horses
6x greater risk of getting laminitis
5x greater risk of getting dermatological conditions
2.5x greater risk of developing chronic musculoskeletal conditions
Insulin resistance
With development of abnormal reproductive function
Diseases linked to excess body fat in cattle and sheep
Fatty liver
Displaced abomasum
Ketosis (7 to 44%)
Diseases linked to being overweight - humans
Diabetes type 2
Heart attacks
Insulin resistance
Chronic inflammation
Reduced fertility
High blood pressure
Stroke
Cancer
Diseases linked to being overweight - horses
Similarities to humans
Cresty neck observed
Equine metabolic syndrome
Insulin resistance, inflammation, vascular compromise, hyper triglyceridaemia, laminitis
The challenge / summary of excess body fat / obesity
Being overweight has become normalised > it is a welfare issue for all animals
Diseases linked are not immediate and not universal > persistence or excess fat tissue
Being overweight for a long time influences fat deposition
Not all fat is the same
Subcutaneous vs
Omental (chronically inflamed) > metabolically active, changes the way the animal handles its energy metabolism
Obesity increases fat stored in muscle
1kg extra body weight = 0.5kg subcutaneous and 0.5kg internal
= insulin resistance and impaired glucose utilisation
What’s the problem with extra fat in the body and in the blood stream (free fatty acids)
Fat is metabolically active > largest endocrine organ in the body
Secretes adipokines / cytokines > leptin, adiponectin, tumour necrosis factor (TNF) interleukins - pro inflammatory
Cytokines have local and systemic effects
More fat = more cytokines > decrease in insulin sensitivity, induce oxidative stress, impair micro vascular function, increased free fatty acids - increases IR and are pro inflammatory
Low grade inflammatory disease is associated with
Chronic inflammation
Insulin resistance
Metabolic laminitis is the horse equivalent of a heart attack
High insulin plus chronic inflammation target = blood vessel lining (endothelium) dysfunction
People = heart attacks
Horses = laminitis > failure of blood flow to the foot
In summary - effect of obesity on physiology
The common biology across species
- Free fatty acids
- Chronic inflammation
- Insulin resistance
- Blood flow
Communication of fat scoring
Role as a professional - one health / one world
Responsibility to understand health and welfare implications
One health approach to improve human and animal health
One world role of nutrition - from farm to fork - environment / global food sources
Causes of obesity
Often owner driven
Recognition - distorted perception normal
Communication - do they understand?
Causes - recognising obesity
Owners and parents do not recognise obesity in their own pets / children
Obese dogs were 2x more likely to have obsess owners compared to non obese dogs
Owners of obsess dogs are 20x more likely to underestimate body fat score compared to owners of normal / overweight dogs
68.8 % of parents of obese children identified their child as being normal weight
Oh children identified as overweight, 66.7% were in fact obese
Keeping an animal lean is the only scientifically proven intervention for increasing healthy longevity
Help them recognise health
You need to be able to explain what you are showing them
You need to have confidence in the technique
Recognise normal seasonal changes in body weight
Largely associated with changes in lipid mass
Why maintain animals at ideal fat score?
Think about:
What are the benefits of not being overweight?
Why should owners have fit animals?
Economics and health for production animals
Save lives, prevents disease, improve health and welfare
Reduce the risk of laminitis in horses - and improve the health and welfare of the horse
Reduce the risk of unhealthy ageing, osteoarthritis, equine metabolic syndrome EMS, of pituitary pars intermedia dysfunction
Reduce muscle loss, stiffness, respiratory disease
Improve immune system
Maintain the health and welfare of your horse
Fit and lean appeals more
Introduction to captive animal diets
Proper nutrition is essential to the health and well-being of all animals
Captive diets for exotic animals have evolved hugely in recent decades due to advanced understanding of species requirements
Suitable nutritionally balanced diets are more readily available now than ever before
However there are still huge gaps in our knowledge and nutritional science for exotics and is a continual learning process as nutritional disorders continue to affect all taxonomic groups
How do we classify herbivores?
Grazers vs browsers
Artiodactyla (even toed) vs Perissodactyla (odd toed)
Mono gastric vs foregut fermenter (ruminants and camels/ / alpacas) vs hind gut fermenter (horses, rhinos and rabbits)
They are largely all anatomically and physiologically adapted to eating plant material
Ruminant feeding types
Concentrate selectors / browsers - 40%
Eg. Roe deer, moose
Intermediate feeders - 35%
Eg. Reindeer, red deer, goat, fallow
Grass and roughage eaters - 25%
Eg. Sheep, cattle, mouflon
What are the differences between grazers and browsers ?
Grazers have relatively larger and more developed rumen and omasum then browsers but a smaller reticulum
Browsers have longer foraging times
Browsers salivary glands secrete tannins to help neutralise the toxins in plants
The livers of browsers are larger to detoxify noxious substances
Browsers do not have rumen stratification > the particles of browse material are polygonal in shape compared to the longish fibre length particles in grass material
Artiodactyla
Herbivores (even toed ungulates)
Foregut fermenters > ruminants (4 chambered stomach), pseudoruminants (3 chambered stomach) and non ruminating foregut fermenters
Also includes suids (mono gastrics)
Captive diets for Artiodactyls
Forage should be the main component of the diet and offered an an ad lib basis
This should be supplemented with a commercial concentrate pellet and or mineral lick to balance micronutrients
Grazing Artiodactyls require high levels of fibre through grass intake
Browsing Artiodactyls normally consume a higher protein content through ingestion of young leaves and shoots
Monitor energy, protein and fat to avoid obesity
Perissodactyla
Herbivores (odd toed ungulates)
Hindgut fermenters eg equids, rhinos
Less effective digestion compared to ruminants, hence require more bulk
Large amounts of time spent feeding and foraging, designed to process high volumes of low quality material
Captive diets for Perissodactyls
Forage should also be the main component of the diet and offered on an ad lib basis
This should be supplemented with a commercial concentrate pellet and or mineral lick to balance micronutrients
High fibre requirements
Monitor energy, protein and fat to avoid obesity
Access to grazing may need to be managed if animals become over prone to laminitis
How do we design / review a diet for a captive hoofstock species?
Need to research the following:
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How do we cater for the nutritional requirements for captive hoof stock species?
Provision of nutrients in the correct amounts - forage supplemented by a balanced pelleted feed - mineral lick
Bulk and roughage - good quality provision of supplementary forage material ( hay and Lucerne) in addition to natural grazing and browse
Ensuring diet provided is of the correct form and structure for the dentition and overall anatomy of the animal
Feeding height (and subsequent management)
Seasonality - how does diet naturally change throughout the year. How does natural body condition of the species change?
Health and condition monitoring to assess effects of diet
How can we provide for behavioural requirements for hoof stock captive species through their diet?
Forage should be the main component of any hoofstock diet > it is what they will spend a significant amount of time engaged in
Creating opportunities for increased feeding and foraging times is crucial in helping to avoid stereotypical behaviours and boredom > complex feeders, hanging browse etc
Food presentation methods to compliment group structure and hierarchy
Diet variety not as necessary with hoof stock
Paddock access - nutritional benefit, also promotes increased activity as well as room for individuals to disperse
Browse - essential for browsing species
The problem with browse
Browse material is an essential part of the feeding programme of any obligate browser (giraffe, okapi, black rhino) and an important part of diet for intermediate feeders
The problem is we don’t have enough of it!
Sourcing enough browse year round is a major challenge for many zoos
During the summer we barrel browse for silage to be fed over the winter
Provision is increasing year on year but it remains significantly lower than what’s required
Lucerne hat is the next best substitute but still doesn’t compare to browse
Case study - a banteng is presented with diarrhoea and the cause is dietary.
What questions should you ask?
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The evolution of diets for captive hoofstock
Diets have evolved hugely in the last couple of decades
Zoos are moving away from inappropriate ingredients such as produce and grains
Greater focus on forage and browse provision
Greater emphasis on food presentation / behavioural stimulation
Hoof stock diets are fairly simple in design- no need to over complicate them or offer treats
Carnivore nutrition
They don’t eat meat - they eat animals
Need a range of nutrients from bones, fur, organs, muscle etc
Simple mono gastric digestive system
Public perception - our job to educate
Cull and feed back in
Gastrointestinal disease in captive cheetahs
Positive correlation between provision of whole carcass prey and reduced incidence of gastritis
Positive correlation between gastritis risk and often or always feeding of horse meat
Cheetahs fed commercially prepared diets had highest prevalence of loose faeces
Provision of ribs and long bones at least once a week associated with lower odds of vomiting
Captive carnivore diets
Focus on whole carcass / prey material
Meat only needs supplementation eg. Ca: P balance
Metabolic bone disease and skeletal abnormalities
Taurine - essential amino acid
Hypervitaminosis A
Behavioural needs
Starve and feast days?
Primate nutrition
Dietary niches of primates are vast
Many will consume various items depending on seasonal variability
Different modes of digestion - eg. Ruminant like tract of colobines
Captive primate diets - key considerations
Wild diet composition and feeding strategy
Digestive system and anatomy
Ingredient selection
Dietary variation - reduce risk of boredom
Lifestage and how requirements may change
Fibre content - help prevent GI disturbances
Micronutrient balance - Ca:P ratio
UV lighting provision - vitamin D synthesis
Disease susceptibility eg. Iron storage, diabetes
Obesity risk
Dental health
Seasonal dietary changes
Food preservation and behavioural needs
Group hierarchy and social feeding
Diet formulation for zoo species - nutritional, physiological and behavioural needs
Nutrients required in the correct amounts
Structure required by the digestive system including the teeth
Stimulation that promotes natural feeding behaviours
Nutritional needs for zoo species
Fibre, fat and protein levels
Mineral / vitamin - supplementation
Calcium / phosphorus
UV
Physiological needs for zoo species
Fibre and bulk
Roughage feeding
Dentition
Feeding height
Size of feed items
Food presentation
Seasonality
Behavioural needs - zoo species
Extend foraging time
Food preservation
Dietary variety
Invertebrate items
Whole prey
Paddock access
Browse
Naturalistic feeding
Positive life experience (PLE) - zoo species
Using food to promote natural behaviour, feeding or otherwise
Allowing for a prolonged foraging time in line with natural ecology and preventing boredom
Increasing activity levels to maintain health, fitness and help prevent obesity
Disperse aggression
Promote expression of natural behavioural repertories
Seasonal and natural feeding
Diet formulation for zoo species - challenges of replicating a natural diet
Not possible to exactly replicate a natural diet
Info required on wild and suitable captive diets, nutrients required, digestive system and adaptations, foraging behaviour and common problems
For many animal species, specific info is not available and therefore we need to revert to the nearest animal model
Zebra > horse
Oryx > cattle
Meerkat > cat
Other challenges - zoo species
Mixed exhibits eg. Energy for life
Selective feeding
Individual specific needs eg. Age, health status
Reproductive status
Group structure and hierarchy
Availability of food items
Sustainable supply of foods
Diet drift
Dietary drift
Keeper drift away from the diet an animal is meant to be fed
Why?
Diet is not weighed out, inadequate diet sheet or records in use by a team, perceived idea of better body condition if animals look on the larger side, anthropomorphism - keepers feel sorry for the animals
The result > animals become overweight and prone to health issues. Diet can become unbalanced
Diet formulation for zoo species - making a recommendation
The combination of background info, target nutrient levels and info relating to digestive physiology all helps to formulate a dietary recommendation for a particular species
Eg. Binturong diet review - diet was reviewed when they first came into the collection
Diet formulation for zoo species - implementation of new or different diets
Changes should be gradual where possible
Sourcing suitable ingredients
Possible trial of new food items
Monitoring > food intake, weight, body condition, behavioural or medical issues, faecal consistency
Common nutritional problems -
Zoo species
Obesity > over feeding, inappropriate nutrition, low activity levels, associated problems like cholesterol level in meerkats
Prevention > appropriate diet and amounts, behavioural stimulation, avoid treats, public education
Common nutritional problems of Zoe species - condition loss
Causes of condition loss include:
Parasite burdens
Reproductive status
Group dominance and uneven food distribution
Stress
Underlying medial issue
Dietary imbalance - diet too low in energy / unsuitable forage quality
Inappropriate environmental conditions
Dental issues
Age
Prevention / treatment of condition loss
Ensure diet is adequately balanced for the species
Check forage quality regularly
Ensure enough food bowls for number of animals / food distribution
Adjust diet for animals losing condition eg. Lactation, geriatric animals, parasite burden animals
Body condition score animals regularly and weight if possible
Carry out faecal checks if an animal starts to lose condition
Ensure efficient reporting between keepers and vet staff / nutritionist to alert to condition losses
Other common nutritional problems - zoo species
Vitamin / mineral abnormalities > deficiency due to inadequate diet, digestive issues affecting absorption, species specific requirements not met, vitamin E and selenium deficiency in equids, copper deficiency in oryx
Toxicity > iron storage disease in lemurs, hornbills, black rhino and some birds
Use custom feed
Avoid food items which contain high levels
Prevention > follow recommendations and subside dietary balance!
Urolithiasis > high protein diet? Aetiology not clear.
Otters - recent study found that provision of fish and crustaceans may have protective effect
Prevention > feed appropriate protein and fibre levels, check diet composition and avoid high levels of meat, ensure adequate water supply
Chronic kidney disease > often seen in ageing animals, common in felids, dietary link? High protein?
Metabolic bone disease in zoo species
Imbalance of Ca/P
Lack of vitamin D3 (UV)
Prevention > feeding a balanced diet (gut loading, supplementation)
Dietary vitamin D3 supp
Supp UV lighting - checked regularly
Natural UV
Conclusion - zoo species
Gather knowledge on wild diets, digestive physiology and recommendations as far as possible
Consider: nutrient composition, diet structure, species individual physiology and natural feeding and foraging behaviour
Strong link between nutrition, health, behaviour and welfare > good nutrition is fundamental to the longevity, breeding success and survival of both individuals and species as a whole
Forages for cows
Grass and forage crops
Conserved forages > hay, straw, grass and maize silage, whole crop wheat
Why do we feed concentrates to the cow?
Forage is unable to supply all protein, energy and minerals for the cow especially:
In early lactation, for high milk yield, when forage quality is poor
Supplement diet with concentrates for > high energy, protein and vitamins / minerals
Supplementary feeds for cows
Primary feeds > soya bean meal, wheat, maize, gluten, sugar beet pulp
By products > brewers grain, Apple pomace, biscuit waste
Energy or protein feeds
Compounds > mixture of straights milked and pelleted, formulated to specification, contents may vary, matched to silage
Premixed blends > similar to compounds but not pelleted, formulated to a specification, dusty and absorb water, can see what’s in them if not milled
Autumn / spring calving beef cow herds
iPad
Beef sucker cow feeding systems
Outdoors = pasture
Housing = grass silage, straw or hay
Near calving > concentrates maybe fed to meet addition energy and protein requirements
Mineral supplementation introduced to prevent metabolic disease
Body condition scoring manipulation during production cycle. Allows body reserves to be built up and drawn on fat reserves at key times during the year
Methods of feeding forages to dairy cows
Grazed grass in summer
Winter / housed all year conserved forage
Zero grazing grass comes to the cows
Methods of feeding concentrates to dairy cows
In parlour feeders - cows eat concentrate during milking
Out of parlour feeders - cows have a transponder visit feeding stations throughout the day
TMR - total mixed ration
A mix of all ingredients eg. Forages, concentrates, barley, root crops
TMR typically mixed and transported to cow in the mixer wagon
How much can a cow eat and what factors affect this?
Week 6 lectures
Energy requirements for a cow
Week 6 lectures
Ration formulation for cows
Week 6 lectures
Energy requirements for animals > body weight and calculations
Week 7 lectures
Exotic animal adaptation of guts and diet
Week 7 lectures
Feeding rabbits and rabbit gut health
Week 7 lectures
Feeding sheep
Week 7 lectures
Obesity and feeding zoo animals
Week 5 lectures
Parasites - the effect on gut health and toxicology
Week 4 lectures
Energy requirements in more detail
Week 4
Acid base balance, bone health, micronutrients, forages
Vitamins and minerals
Week 3 lectures
Healthy guts, microbiomes and probiotics
Week 2 lectures
Poultry and feeding pigs
Week 1 lectures
Circadian rhythms, feeding times across animal species, rhythms in metabolic physiology and consequences of disrupted feeding rhythms
Week 8 lectures
Peripheral clock of animals, food intake as a timing cue and metabolic sensing and circadian desynchrony
Week 8 lectures
Chronobiology - how to read food labels
Week 8 lectures
Feeding horses
Week 9 lectures
Differences between the nutritional requirements of dogs and cats
Week 9 lectures (recording)
