late gestation
TRANSCRIPT
SUSAN SCHOENIAN (Shāy-nē-ŭn)Sheep & Goat SpecialistWestern Maryland Research & Education [email protected] - www.sheepandgoat.com
Seventy (70) percent of fetal growth is occurring.
Important time for udder development and colostrum production.
Rumen capacity is decreasing.
Voluntary feed intake of feed is less, especially during last two weeks.
NEEDS
INTAKE
More feed -- but more importantly, a more nutrient-dense (better quality) diet.
To compensate for reduced feed intake.
To meet demands of growing fetuses.
To support udder development and colostrum production.
To prevent pregnancy toxemia and milk fever.
To ensure the birth of strong, healthy lambs of moderate size (weight).
We want grain!
Energy (TDN) is the nutrient most likely to be deficient, but protein (CP) can also be deficient in the diet, due to a reduced intake of feed.
Nutrient requirements vary:▪ Breed
▪ Size (weight)
▪ Age (lamb vs. mature)
▪ Number of fetuses
▪ Environment
Concentrates are usually necessary to meet the increased energy needs of pregnant ewes, especially those carrying multiple fetuses.
If a low-quality forage is fed, it may also be necessary to provide supplemental calcium (Ca) and/or protein (CP) in the concentrate diet.
Corn is only an energy supplement.
Disease risk Pregnancy toxemia risk (TDN) Milk fever risk (Ca) Poorer immunity (CP)
Higher neonatal mortality Smaller, weaker lambs Reduced colostrum quality
and quantity.
Poorer performance Reduced milk yield Reduced wool production (in
the offspring) due to fewer secondary follicles.
Pregnancy toxemia risk
Milk fever risk (Ca)
Ewes more likely to prolapse their vagina.
Greater risk of dystocia (difficult birthing). Too much internal fatOversized fetuses Fat, lazy ewes
Feed is expensive - why do you want to overfeed it?
Low blood sugar (glucose).
Caused by an inadequate intake of energy (TDN) during late pregnancy.
Leads to a breakdown of fat (energy reserves) into toxic ketone bodies which overwhelm the capacity of the liver (also called “fatty liver disease”).
Most commonly affects fat or thin ewes and those carrying multiple fetuses (also called “twin lamb disease”).
Stress is another risk factor.
POOR SOURCES
Feed stuff % TDN
Poor quality hay < 50
Poor quality pasture < 50
By-products[corn cobs, straw]
< 50
GOOD SOURCES
Feed stuff % TDN
Corn 88
Barley 84
Oats 76
By-products[beet pulp, soy hulls, DDSG]
~75
Commercial (sack) feed ~72
INTERMEDIATE SOURCES
Feed stuff % TDN
Good quality hay > 55
Good quality pasture (low DM) > 60
Calcium (Ca) requirements virtually double during late pregnancy . . . but you need to avoid excessive calcium, too.
Milk fever is low blood calcium.
It is caused by inadequate Ca in the diet or a failure of the ewe to mobilize Ca reserves.
It can occur anywhere from six weeks before lambing to 10 weeks after.1. Pre-partum (non-dairy ewes)2. Post-partum (dairy ewes)
POOR SOURCES
Feed stuff % Ca
Corn 0.02
Oats , wheat 0.05
Barley 0.06
GOOD SOURCES
Feed stuff % Ca
Limestone 34.0
Dicalcium phosphate 22.0
Trace minerals 14-18
Dry kelp 2.72
Balancer pellet 1.60
Legume hays 1.3-1.5
INTERMEDIATE SOURCES
Feed stuff % Ca
Grasses 0.30-0.50
Soybean meal 0.28-0.38
Complete (sack) feed 0.55
Soils in the Northeast are considered low in Se.
During late gestation, selenium crosses the placenta to the fetuses.
Low levels of selenium and/or vitamin E can result in . . .
White muscle disease (lambs)1. Congenital vs. acquired2. Cardiac vs. skeletal
Poor reproductive performance Poor performance
Image source: Informed Farmers (Can)
Free choice mineral mixes usually provide adequate selenium . . . but do not guarantee adequate intake.
Adding a selenium-fortified mineral mix to a concentrate ration will ensure adequate intake of selenium and other minerals.
Selenium and vitamin E can be also supplemented orally via gels or pastes.
On farms with a diagnosed history of white muscle disease or selenium deficiency, Se/Vitamin E injections may be given per the advice of a small ruminant veterinarian.
Labeled dosage for Bo-Se® [Rx] 1 ml/40 lbs. (1 ml min) for lambs
Not labeled for lambs under 2 weeks of age
2.5 ml/100 lbs. for ewes
Not labeled for pregnant ewes
Se deficiency
Se toxicity
Make sure all ewes can eat at the same time.
Make sure all ewes get their fair share of all feed.
Pay particularly close attention to ewes that are old or compromised in some way.
Separate pregnant ewe lambs from mature ewes and feed separately.
Remove rams after breeding season and feed separately.
Do not feed on the ground.
Stress can predispose pregnant ewes to many problems.
Minimize stress during late pregnancy.
Examples: Missed feedings Erratic feeding schedule Shearing, crutching Moving, handling Mixing groups Dogs Visitors Weather (be prepared)
This is my special time.
Leave me alone.
Lack of exercise may increase the chances of pregnancy toxemia and other problems.
Daily exercise is recommended through-out pregnancy.
Exercise can be encouraged by separating feed, water, and minerals.
Fit, active ewes have fewer problems.
Vaccinate pregnant ewes approximately 1 month (but at least 2 weeks) before they are due to lamb.
Lambs will acquire temporary, passive immunity via the colostrum -- provided they consume adequate colostrum
What is adequate?~10% of BW in first 24 hours
Ewes not previously vaccinated will require two vaccinations, 3-4 weeks apart.
If the dam was not vaccinated or the lamb did not consume adequate colostrum, the tetanus antitoxin should be given at the time of docking and/or castrating, especially if rubber rings are used.
Lambs from vaccinated dams should be vaccinated twice, 3 to 4 weeks apart, starting at 6 to 10 weeks of age.
Ewes suffer a temporary loss of immunity to gastro-intestinal worms around the time of parturition. Fecal egg counts increase
If lambing occurs in the spring, the egg rise will coincide with the hypobiotic (dormant) larvae resuming their life cycles.
The periparturient egg rise is the primary source of infection for new lambs.
Traditional approach Deworm all ewes prior to
lambing (2-4 weeks prior).▪ Use an anthelmintic that
is effective against hypobiotic larvae (e.g. ivermectin).
New approaches Increase protein level in late
gestation ration. How much? NRC by 30%
Use the FAMACHA© system and Five Point Check© to determine which ewes require deworming.
In feed or mineral[no withdrawal period]
1. Bovatec® 2. Deccox® 3. Rumensin® [Rx]
Why?1. FDA approval: to prevent
coccidiosis in lambs. Kill or inhibit coccidia
2. As an aid to prevent abortions caused by Toxoplasma gondii.
3. Rumen modifier: propionic acid by-pass protein digestive problemsmethane gas
Coccidiostats, especially Rumensin® can be toxic to equines and dogs.
Why? To prevent abortion.
1. If the flock has a history of diagnosed abortions that can be controlled with antibiotics, e.g. Chlamydia, Vibrio.
2. In the event of an abortion storm.
How?1. Feed chlortetracycline
(aureomycin) at a rate of 80 mg/head/day during the last 6 weeks of gestation [OTC].
2. Inject oxytetracycline (LA-200) at two week intervals during late gestation [Rx].
Results in cleaner, drier, healthier environment for ewes and especially lambs.
Shorn ewes are less likely to lay on their lambs.
Shorn ewes are more likely to seek shelter for lambing.
Shorn ewes take up less space in the barn and around feeders.
Results in cleaner fleeces. But . . . shorn ewes require
shelter and more feed.Image by Kelly Cole
FACILITIES
Clean, dry, draft-free building
Drop area
Jugs (small pens for bonding)e.g. 5 ft. x 5 ft
Individual feeders and waterers
Grafting stanchion
Mixing pens
Clean, well-rested pasture
Shelter
Emergency jugs
SUPPLIES (partial list)
Colostrum source Esophageal feeding tube OB sleeves and lubricant Disinfectant for dipping navels Prolapse harness or spoon Needles and syringes Nipples or teats Lamb milk replacer Propylene glycol Calcium Antibiotics Thermometer Record keeping booklet More…
DO’S
Increase nutrition (gradually) Feed pregnant ewe lambs
separately Encourage daily exercise Minimize stress Vaccinate for CD-T Manage periparturient
egg rise Feed a coccidiostat Shear or crutch ewes Prepare facilities Gather/inventory supplies
DON’TS
Overfeed Underfeed Stress ewe Introduce new animals Change groupings Leave rams in Worry
