Lecture 13: Small Ruminants Production and Reproduction Flashcards
Give a summary of sheep production?
-Farm flocks of 50 ewes to >100 breeding ewes (smaller compared to dairy)
-Meat production (very common)
-Sheep dairies (small but growing) v small
-Fibre (wool) production (very small) niche markets only -wool not popular since its costs more to shear then profit from wool
Give a summary of goat production?
-Goats as pets (common) compared to sheep/lambs
-Dairy goats (common) :larger more common but opposite to sheep
-Meat production: (less common)
-Fibre (angora, chasmere) production (very small, niche markets) speciality fibre more $
TRUE OR FALSE: Goats are more personable and intelligent which is why people have them as pets more
TRUE
TRUE OR FALSE: most goat meat is a by-product of the dairy industry but there are meat breeds.
TRUE
-If you buy goat from a store that says it was made in CA it probably came from a dairy goat
What is the meat sheep/goat production cycle?
- Females joined with males. Typical breeding period of 30-42d (2-3 cycles)
2.Females gestate 150d - Females give birth in the spring: ex if bred in November will give birth in April
- Lambs/kids are weaned at 60d up to 4 months of age
- Lambs/kids marketed at weights from 50lb (2-3months) to 110lb (up to 12 months)
- Finish on farm and then direct to slaughter or sales barn
- (split at 4) Replacement females are bred at 7months but depends on goal of producer
How is meat production marketed and when is a producer considered successful?
-kg of lamb marketed/ ewe/year we can optimize this by:
-Optimal pregnancy rates/laming rates (>95% pregnant from a breeding exposure and <5% abortion rate)
-Optimal prolificacy (# of lambs born per ewe) can have 2 or more lambs born/ewe lambing very breed dependant
-Optimal lamb survival (<3% stillbirth; <5% lamb pre-weaning mortality)
-Optimal lamb growth (350-500 gm/day varies by breed and production style)
-Lamb crops per year
-Accelerated lambing (3 lambing in 2yrs)
-Ewes lamb every 8 months rather than every 12 (breeding exposure + gestation = 6months; lactation=2months; having a group lambing in jan, may and September; requires breeding out of season)
-Ewe survival rate/turnover
-<5% ewe mortality/year
-20% cull rate with >60% of those as voluntary culls
Note* when looking at cull rates want to look at involuntary (no other choice) vs voluntary (producer makes decision too much genetics or proactive decisions)
What is the breeding cycle for dairy goats?
- Does freshen in the spring
- Kids are removed at birth
- Buck kids often sold at a few days
- Surplus buck kids usually marketed at 4m
- (comes form 2) Doelings reared on milk replacer for 2 m
- Replacement dwellings are bred at 7-10m to kid at 12-15m
7.Does are exposed to the buck-natural breeding, breeding exposure 30-40d usually 7m into lactation - Does gestate 150d
- Does are dried off after 305d (10m) lactation & dry for 2m
How do you measure success in the goat dairy industry?
-In addition to optimal reproduction and kid/doe survival
-Milk production
-L’s of milk/day/doe
-Kg of milk/lactation (peak, length)
-Percent butterfat and protein optimized
-Low rates of mastitis
-Treatment rates
-Somatic cell counts/culture results
-High milk quality
-Low bacterial counts
-No inhibitors, ex antibiotics
-Good taste and colour (off flavour can be issue, unique challenge compared to dairy cows
What are some management strategies for breeding lambs?
-Short day breeders- seasonally polyestrous
-only have estrous cycles in the autumn to early winter don’t breed in late winter, spring and summer
-Most breeding is by group rather than hand-mating or artificial insemination
-Ram: ewe ration is important and changes with different breeding programs (1:40 ram:ewe)
-Estrous cycle is 17d (sheep) 21d (goats)
-Males typically left in with females 2-3 cycles
Why would we want to manipulate the estrus cycle?
-Synchronization of estrus tightens lambing period (less labour since not spread out, market uniform crop)
-Introduction of estrus allows for out of season lambing
-Produce milk/lambs/kids off season
-Ewes lamb more than once/year ex every 8 months
-Introduction of estrus out of season allows for winter milk on dairies
-Usually done by giving an exogenous source of progesterone
-CIDR (controlled internal drug release) intervaginal device allows for it to get absorbed but requires handling facilities to take in and out (in and out of season)
-MGA (melengesterol acetate-in feed) but need enough bunk space, (in and out of season)
-Control of photoperiod control (only option for out of season)
-In the ‘transition’ period we can induce estrus using the ‘ram effect’ (only transition period take ram away and bring back supposed to bring into heat then swap out for breeding ram)
What are the important facts about infectious abortions?
-Abortion outbreaks are common in sheep and goats (10-50%)
-Normally <2% of pregnant female/year abort
-If 5-7% then enzootic problem (require good record keeping (could be missed if lower level)
-Will see clusters start ~ 2w prior to start lambing/kidding
-MANY ARE ZOONOTIC (important from public health standpoint)
How is abortion managed?
-Diagnosis is critical to management
-Send placenta and fetuses to vet diagnostic lab
-Biosecurity and protection of farm workers important for infectious diseases
-Infected aborted ewes/does
-contaminated environment
-Protective clothing of workers (N95 most through air as well)
-Control much more efface than treatment
What are some common causes of small ruminant abortion?
-Chlamydophila abortus (zoonotic, in air, very common in dairy goats and sheep)
-Coxielle burnetii - Q fever (zoonotic, in aborted materials ie shed in birth fluids & milk & feces, and aerosolized very common, human disease) can also be common in cattle but affects very across species
-Campylobacter (zoonotic, mainly in sheep less common in goats, spread also by carrion eating birds, antimicrobial resistance)
-Toxoplasma gondii (environmental issues, parasites carried by cats from mice, most common cause in sheep
What causes goiter? And what are some symptoms?
Cause
-Insufficient iodine in the diet of pregnant ewes/ does
-Not zoonotic or infectious
-Great Lakes region deficient
Symptoms
-Enlarged thyroids, still born or aborted fetuses
-Underdeveloped fetus: still born with no hair
-Supplement through gestation by iodized salt block
What is lamb and kid mortality?
-Most losses at birth and fist few days of life
Goals
-3% still born
-5% neonatal mortality
Reality
-Closer to 15-20%
Risk periods
-Late pregnancy
-Lambing/kidding time
-First or second week of life
