5. Small ruminant production and husbandry Flashcards
What are some mountain breeds of sheep?
Rough fell
Welsh mountain
Scottish blackface
Swaledale
What are some hill breeds of sheep?
Lleyn Clun forest Kerry hill North Country Cheviot South country cheviot Exmoor horn
How are lambs managed on a hill farm?
Look for little more than 1 lamb per ewe per year
Hill ewe bred pure for 3-4 lamb crops
Castrated hill lambs are sold for meat + entire male lambs are kept or sold for breeding
Ewe lambs are retained as flock replacements
What are draft ewes?
Hill ewes often sold after several crops of lambs
Will often have more productive seasons in less harsh conditions
Crossed with long-wool tups to produce halfbreed ewes
What are some breeds of longwool sheep?
Teeswater
Wensleydale
What is a halfbred?
Longwool x mountain/hill i.e.
- masham
- Welsh halfbred
- Scottish halfbred
- Scottish mule
What are benefits of using halfbreds?
Hardiness and good mothering ability from mother; frame size prolificacy and milk production from father
Heterosis
Aim for 2 lambs per ewe per year
Crossed with a terminal sire to produce fat lambs
What are some down breeds & continentals (the terminal sires)?
Suffolk Charollais (France) Oxford down Beltex (Belgium) Hampshire down Texel (Netherlands)
What are some benefits to using the terminal sires?
Rapid growth rates
Good carcass conformation
Hardiness less important
What are advantages to using the stratified system?
Sheep matched to the land type
Productive utilisation of marginal land
Productive life of hill ewes extended
Benefits of heterosis in mules/halfbreds
What are disadvantages to using the stratified system?
Increased movement of sheep can equal higher disease spread
Open flocks - compromised biosecurity
Cross breeding, no control of maternal line, open flock - limited genetic improvement
What are some alternative modes of production?
Store lambs
Closed single breed flocks (Lleyn, Romney, Easycare)
Crossbreed flocks (Lleyn x Texel)
Crofting
Direct hill/upland x terminal sire production
What is fat lamb production?
Lambs sold for slaughter are around 45kg liveweight
Lambs sold through markets are sold liveweight
Lambs sold to slaughter may be sold either liveweight or deadweight
How are carcasses valued based on conformation?
Scored on a scale E,U,R,O,P from excellent to poor
Conformation is determined largely by genetics and nutrition
How are carcasses assessed based on fatness?
Scored 1,2,3L,3H,4L,4H,5, determined largely by nutrition with genetics and disease also playing a role
What are other factors affecting carcass value?
Total or partial carcass condemnations - abcesses - arthritis - T.Ovis cysts Liver condemnations - F.hepatica, T.hydatigena, E.granulosus and abcesses Dirty animals
How do lamb prices fluctuate?
Prices vary with supply and demand (both export and domestic)
prices peak at easter as most sheep are lambing
Trough in summer when there are lots of spring born lambs
Weather impacts supply, health of the wider economy impacts demand
What are factors affecting profitability?
Variations in variable costs (grain prices, availability of straw, replacement costs)
Fuel price variation
Labour availability and cost
Disease
What separates the most profitable from the rest is there ability to achieve optimum productivity from there system
What are important timings in the sheep year?
Gestation = 147 days Weaning = 12-16 weeks Scanning = 45-90 days of gestation Birth 1st mating = 18 months (lambing as a gimmer) - 7 months for a ewe lamb Birth - slaughter - 4 months (fat lambs) - 9 months (short - keep store lambs) - 12 months (long - keep store lambs)
What is tupping?
Sheep are short day breeders (seasonally polyestrus)
Increased darkness, increased melatonin & GnRH release = return to cyclicity (females), increase in testes size & sperm production for males
Mountain/hill breeds - peak fertility october/november and december
Terminal sires - longer breeding season (Dorsets all year round)
How is tupping managed?
Oestrus cycle approx. 17 days Tups usually left in for 2 cycles Raddle marks, keel paint - identifies ewe as tupped - planning of lambing - identifies return to oestrus (non-pregnant) Tup-Ewe ratio varies - 1:50 for tups - 1:20 for tup lambs/non-synchronised single sire groups - 1:10 for synchronised lambs
What are the reproductive targets that should be met?
BCS score at tupping (scale 1-5): 2.5-3 for hill, 3.5 for lowland
Conception rate 90%
Barren rate 2%
Scanning %: lowland 200% - 220%, Hill 120%
What are signs of illness in sheep?
Lameness Thin Reduced abdominal fill Diarrhoea Coughing Increased respiratory effort About the head: no 'smile', clenched cheek muscles, drooping eyelids/orbital tightening, hanging ears, inattentive, cud spillage/cheek packing Behaviour: straining, kicking at belly, flank watching, pruritus, recumbency, inappetence, quidding
What are some common internal parasites?
Gastro-intestinal nematodes
Liver Fluke
Cocidiosis
Cryptosporidiosis
What is the impact of gastro-intestinal nematods?
Death Disease Lost production Lambs most affected Ewes have an increased susceptibility around lambing time Rams more susceptible then ewes
How are gastro-intestinal nematodes controlled?
Anthelminitic resistance widespread in sheep worm populations
Must use an integrated approach:
-genetics: breeding more resistant/resilient sheep
- avoidance: exposure os susceptible animals is limited
- management: improving ewe nutrition at lambing time reduces susceptibility to worms, moving lambs of the farm before worm count peaks
- effective treatment - resistance status must be known, ineffective products not used, quarantine treatments, reduce selection pressure for resistance
What is liver fluke?
Parasite formerly confined to the wetter parts of the UK - range increasing Resistance to one class of flukicides is now common
How is liver fluke controlled?
Effective use of flukicides
Avoidance of highly contaminated areas
Habital modification to reduce contamination
What are some examples of external parasites?
Sheep seab, fly strike, lice, ticks, keds, chorioptic mange, midges
What is sheep seab?
Psoroptes ovis - mite
Extremely itchy, wool loss, weight loss, lost production, can be fatal
Increased incidence since end of compulsory organophosphate dipping
More common in higher sheep density
What is fly strike?
3 fly species, Lucilia sericata (greenbottle) most common Lay eggs, especially in damp or soiled fleece Maggots hatch out + eat through skin Fatal unless treated quickly Prevention involves: - minimise fly breeding grounds - minimise fleece soiling - well-times shearing - application of preventative products
What are causes of lameness?
Most common = infectious + contagious
Scald & foot-rot
CODD
What are the causes of abortion?
Most common causes are infectious, most common being contagious (EAE)
2nd most common from contaminated feed (Toxoplasmosis)
- salmonella
- campylobacter
- listeria
Vaccines are available
Many are zoonotic
What are clostridial diseases?
In soil and gut in small numbers e.g. pulpy kidney, tetanus, black disease, gas gangrene
Death common and the prognosis is poor
What is the vaccination schedule for clostridial diseases?
All require two injections in primary course with an annual booster
- 4-6 weeks prior to lambing with passive immunity to the lamb lasting 8-12 weeks
What is pasteurella disease?
Bacterial disease
Stress can cause outbreaks
Some stand alone vaccines, initial course of two injections
What are Johne’s disease and CLA?
Johne’s disease = infectious wasting condition
Faeco-oral transmission
Test & cull, vaccination
CLA = Caseous Lymphadenitis, abscessation of lymph nodes, wasting
Transmission is via rupture of abscess, inhalation, contamination of skin wounds
Test & cull prior to sale
What are Maedi-Visna and OPA?
Maedi-Visna = Wasting, respiratory signs (maedi), udder induration, progressive ascending paralysis (visna)
- respiratory transmission
Test & cull, snatch lambing
OPA = Ovine Pulmonary Adenocarcinoma
- respiratory transmission
- scan lungs & cull, snatch lambing, avoid housing
What is scrapie?
Transmissible spongiform encephalopathy
Wasting and neurological signs
Susceptibility dependant on genotype
NOTIFIABLE
What is the normal course of clostridial and pasteurella vaccines?
Many clostridial disease vaccines of varying valency
Two combined pasteurella and clostridial vaccines
1 pasturella only vaccines
All, two injections 4-6 weeks apart, annual boosters
What are goats used for in the UK
Most goats are kept as pets
Hair + meat are minor, most commercial goat enterprises are dairy
What are the legislation differences and similarities in the UK goat and sheep industries?
All livestock are legally food producing animals whether pets or not
Goat disbudding is an act of veterinary surgery, anaesthesia must be used
Legal maximum age for castration performed by anyone other than a veterinary surgeon 2 months (3 months in lambs)
What is general housing , nutrition and management of goats?
Goats don’t like getting wet, shelter required
Most goats are housed year round on straw, regular foot trimming required
Many pet goats are overfed concentrates, can lead to laminitis, obesity and obstructive urolithiasis (males), problem in dairy herds too
Artificial rearing of kids is common
TNZ is smaller
How are parasites controlled in goats?
Rarely get fly strike, do not get sheep scab
Evolutionary browsers not grazers, have not evolved to cope with gastro-intestinal parasites
No longer a licensed anthelmintic produced on the UK market for goats - reason why most are housed all year round
What are vaccines available for goats?
Only three licensed vaccines for goats: Johne’s disease vaccine (gudair), S.aureus mastitis vaccine (Vimco) and Q fever vaccine (Coxevac)
Goats respond poorly to multi - valent clostridial vaccines
Antibody response shorter lived + lower than in sheep
Recommended approach is Lambivac (4 in 1), inital course as in sheep, but with boosters 3 times a year
What are the basics of sheep nutrition?
Ruminants
Fed from products of fermentation in the rumen
Allows digestion of cellulose
Grass is a viable feed stuff for sheep
How to tell if there is insufficient grass available?
If you can find golf balls easily in the grass
How should nutrition prior to tupping be managed?
Optimal reproductive performance occurs when ewes at target BCS (3-3.5)
Ewes that drop below NCS of 2 at any point in the reproductive cycle will have a decreased reproductive performance
Flushing = ewes on increased plane of nutrition for 3 weeks prior to tupping, increased ovulation rate isn’t always desirable
Rams should be in a BCS of 3.5-4 at the start of tupping
Avoid red clover, phytoestrogens
Beware of brassicas - gaitrogens
How should nutrition after tupping be managed?
During early + mid-pregnancy requirements not much different to maintenance
Ewe lambs - met requirements but don’t over feed
M +/- 10% is a good rule of thumb
How should nutrition during late pregnancy?
70% of lamb growth is in the last 6 weeks of gestation
Ewe undernutrition = pregnancy toxaemia, low birth weight and low brown fat levels
Can allow a ewe at BCS ≤2.5 lose 0.5 BCS over last month of lambing and first bit of lactation = 2MJ ME per day
What is neonatal mortality?
Major cause of lost productivity in uk flocks
5% achievable
10-25% may occur
What are causes of neonatal mortality?
Dystocia Hyperthermia Watery mouth disease Septicaemic Colibacillosis Omphalophlebitis Clostridial disease
How is neonatal mortality managed?
Dystocia = husbandry, shepherd’s experience, timely + correct intervention
Septicaemic colibacillosis = good lambing shed hygiene, good quality + plenty of colostrum, navel dipping, correct veterinary advice
Omphalophlebitis = good lambing shed hygiene, colostrum and navel dipping
Clostridial disease = vaccination of ewes, colostrum intake
What are causes of peri-parturient ewe mortality?
Dystocia Vaginal + uterine prolapse Metritis Mastitis Clostridial disease Hypomagnesia
How are the causes of per-parturient mortality managed?
Uterine prolapse - Vet attention ASAP
Metritis - good hygiene when assisting lambing, prompt antibiotic/anti-inflammatory treatment, good nursing care
Mastitis - good shed hygiene, good nutrition, for milk production, prompt antibiotic/anti-inflammatory treatment
How should lambs be identified?
All holdings with goats and sheep in the UK must have a CPH (county parish holding) number
Below 12 months of age single “flock ear” tag is permissible
Above 12 months two identifiers, one of which must be an ear tag (individual identifiers)
All sheep must have an EID
When does shearing take place?
Most commonly May, June, July
Some before lambing, some in winter
Necessary to avoid heat stress, fly strike, etc.
