sheep exam 2 Flashcards
sheep industry set up
Anything less than 500 head is considered
small (estimates consider that you need 150
animal to make a profit)
Purebred – produce replacement ewes and terminal sire rams
Commercial – use a mixed breed ewe and terminal sire to produce a meat lamb
range sheep
Range
– Basically keep the sheep out at pasture all yearBasically keep the sheep out at pasture all year
roundround
– Put out rams when requiredPut out rams when required
– Supplement feed in winterSupplement feed in winter
»» Minimal input costsMinimal input costs
»» PredationPredation
»» Lack of shelterLack of shelter
»» Disease control (parasites)
Farm flocks – semi-confinement
– Summer at pastureSummer at pasture
– Winter in corral/barn systemWinter in corral/barn system
– AdvantagesAdvantages
»» Multiple births, low mortality, maximum growth,Multiple births, low mortality, maximum growth,
control of the breeding seasoncontrol of the breeding season
– DisadvantagesDisadvantages
»» Increased costs, more manpower, facilitiesIncreased costs, more manpower, facilities
»» Increased diseaseIncreased disease
Feedlot
– Buy in lambs whenBuy in lambs when weaned 60-80lbs
–– Fatten to slaughterFatten to slaughter
110lbs110lbs
–– Problems as in anyProblems as in any feedlot
sheep dairy
RareRare
200 day lactation –200 day lactation –
600kg yield600kg yield
–– SPECIFIC FORSPECIFIC FOR
CHEESE PRODUCTION
Biological pasture control
Resistant to many of the toxic plants that
plague cattle (leafy spurge, tansy ragwort)
Can clear pastures and make them safe for
cattle
Note: Very few parasites cross the species
barrier
– Rotational grazing
diff breeds
Suffolk – good terminal sire
Cheviot – hardy
Dorset – Long breeding season
Finn – Prolific
Arcott - highly productive
-merino: make WOOL
Exotics
Cross-breeds – F1
markets on sheep
Wool- worthless
New crop lambs – sucking lambs 45lb (<60d)New crop lambs – sucking lambs 45lb (<60d)
–– Premium ethnic market
Fat lamb – 120lb lambFat lamb – 120lb lamb
Mutton – largely worthless unless specific marketsMutton – largely worthless unless specific markets available
Specialized slaughterS
Environmental
Production targets for a good
farm flock
Lambs born per ewe – 2
Lambs weaned - 1.7
Fertility – 90%
Lamb crops per year - 1.5 (hard to do)
Average daily gain – 0.3-0.5kg/day
-Age at first lambing - 1 year
Lamb mortality 5%
seasonal breeding
The sheep is a seasonal breeder
–– As the length of daylightAs the length of daylight
decreases, there is
increased production of
melatonin from the pineal
gland which triggers the
onset of normal estrus cycles
The exact breeding seasonThe exact breeding season
is dependent on the breed
seasonal breeding dif breeds
-upland sheep: (scottish) hardy breeds, short fall breeding season. may only cycle 2 times in november
-lowland breeds -suffolk, more productive, longer breeding season sept-jan
-occasional breeds (dorset) almost breed year round.
rams needed for breeding
– If open range – 3 per 100 ewesIf open range – 3 per 100 ewes
– If confined 1 per 50-60If confined 1 per 50-60
– Out of season or if the ewes are synchronizedOut of season or if the ewes are synchronized
may need 1 per 20may need 1 per 2
choosing rams
-full physical: look at feet, teeth, raddle sores and do a breeding soundess exam.
-always put young rams with a small group of experienced ewes for first year. 1/20 ewes.
ewe evaluation
-records on productivity and mothering ability
-full physical, cull any problems
-aim for body condition score of 3.5-4 at breeding time.
-increase nutrition prior to breeding until at least 6 weeks preg.
controlling the breeding season in ewes
-naturally long breeding seasons
-light effects: put sheep in barn overnight for long period to fool pineal gland.
-melatonin implants: slow release capsules mimic bodies response to decreasing day length.
- Sponges/CIDR: A progesterone
releasing sponge placed in the vagina to mimic diestrus. at sponge removal time can treat ewe with FSH to stimulate ovulation.
-Melengestrol Acetate
– Progesterone compounded added to the feed. have the same effect as vaginal sponges.
-rams: advance breeding season by several weeks and synchronize.
how to use rams to change breeding cycle
– Works only to advance the breeding season by several weeks and synchronize
– Ensure that the ewes have absolutely no contact with a ram whatsoever for 6 weeks
– Then put in a vasectomised ram for 2 weeks
– The sudden arrival of the ram makes all the ewes come into a non-fertile estrus
– Put in fertile ram 2 weeks later
Gestation
-145 days (5 months)
Maintain BCS for 6 weeks
Then you can allow BCS to fall by one full point during pregnancy
Need a raising plane of nutrition in the last phase of pregnancy
pregnancy
-ultrasound: scan 7-12 weeks after breeding
-scan we weeks after ram turn out
-want to diagnose preg and see how many lambs
-health issues: abortion, vaccinate in late preg to ensure transfer to lamb in colostrum
