late gestation

Late gestation: preparing for lambing 2/25/12

by Susan Schoenian 1

SUSAN SCHOENIAN (Shāy‐nē‐ŭn)Sheep & Goat SpecialistWestern Maryland Research & Education [email protected] ‐ www.sheepandgoat.com

Seventy (70) percent of fetal growth is occurringof fetal growth is occurring.

Important time for udder development and colostrum production.

Rumen capacity is decreasing

NEEDS

decreasing.

Voluntary feed intake of feed is less, especially during last two weeks.

INTAKE



More feed ‐‐ but more importantly a 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

We want grain!

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).

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:q y▪ Breed▪ Size (weight)▪ Age (lamb vs. mature)▪ Number of fetuses▪ Environment



Concentrates are usually necessary to meet the 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 riskPregnancy toxemia risk (TDN)Pregnancy toxemia risk (TDN)Milk fever risk (Ca)Poorer immunity (CP)

Higher neonatal mortalitySmaller, weaker lambsReduced colostrum quality and quantity.

Poorer performanceReduced milk yieldReduced 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).

h l fToo much internal fatOversized fetusesFat, lazy ewes

Feed is expensive ‐why do you want to overfeed it?

Low blood sugar (glucose).g (g )

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 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 GOOD SOURCES

Feed stuff % TDN

Poor quality hay < 50

Poor quality pasture < 50

By‐products[corn cobs, straw]

< 50

Feed stuff % TDN

Corn 88

Barley 84

Oats 76

By‐products[beet pulp, soy hulls, DDSG]

~75

Commercial (sack) feed ~72( ) 7

INTERMEDIATE SOURCES

Feed stuff % TDN

Good quality hay > 55

Good quality pasture (low DM) > 60

Calcium (Ca) requirements virtually double during late 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)



GOOD SOURCES INTERMEDIATE SOURCES

POOR SOURCES

Feed stuff % Ca

Limestone 34.0

Dicalcium phosphate 22.0

Trace minerals 14‐18

Dry kelp 2.72

Balancer pellet 1.60

L h

Feed stuff % Ca

Grasses 0.30‐0.50

Soybean meal 0.28‐0.38

Complete (sack) feed 0.55

POOR SOURCES

Feed stuff % Ca

Corn 0.02

Oats , wheat 0.05

Barley 0.06

Legume hays 1.3‐1.5

Soils in the Northeast are id d l i S

Image source: Informed Farmers (Can)

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 performancePoor performance



Free choice mineral mixes usually provide adequate usually provide adequate selenium . . . but do not guarantee adequate intake.

Adding a selenium‐fortified mineral mix to a concentrate ration will ensure adequate i t k f l i d th 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 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 age2.5 ml/100 lbs. for ewes

Not labeled for pregnant ewes

Se deficiency

Se toxicity



Make sure all ewes can eat at the same timecan 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.

S t t l b f 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

This is my special time pregnant ewes to many

problems.

Minimize stress during late pregnancy.

Examples: Missed feedingsE i f di h d l

special time. Leave me alone.

Erratic feeding scheduleShearing, crutchingMoving, handlingMixing groupsDogsVisitorsWeather (be prepared)



Lack of exercise may increase the chances of 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 p gewes approximately 1 month (but at least 2 weeks) before they are due to lamb.

Lambs will acquire temporary, passive immunity via the pass e u ty a t ecolostrum ‐‐ provided they consume adequate colostrum

What is adequate?~10% of BW in first 24 hours



Ewes not previously vaccinated will require two qvaccinations, 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 usedrubber 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 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 yp(dormant) larvae resuming their life cycles.

The periparturient egg rise is the primary source of infection for new lambs.



Traditional approachDeworm all ewes prior to lambing (2‐4 weeks prior).▪ Use an anthelmintic that

is effective against hypobiotic larvae (e.g. ivermectin).

New approachesIncrease protein level in late

t ti ti 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]

Why?FDA l t t [no withdrawal period]

1. Bovatec® 2. Deccox® 3. Rumensin® [Rx]

1. FDA approval: to prevent coccidiosis in lambs.

Kill or inhibit coccidia

2. As an aid to prevent abortions caused by Toxoplasma gondii.

R difi3. Rumen modifier:propionic acidby‐pass proteindigestive problemsmethane gas

Coccidiostats, especially Rumensin® can be toxic to equines and dogs.



Why? To prevent abortionTo 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 y

(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, h l hi i f 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 buildingDrop areaJugs (small pens for bonding)e.g. 5 ft. x 5 ftIndividual feeders and waterersGrafting stanchiongMixing pens

Clean, well‐rested pastureShelterEmergency jugs

SUPPLIES (partial list)

Colostrum sourceEsophageal feeding tubeOB sleeves and lubricantDisinfectant for dipping navelsProlapse harness or spoonNeedles and syringesNipples or teats

b lk lLamb milk replacerPropylene glycolCalciumAntibioticsThermometerRecord keeping bookletMore…



DO’S DON’TS

Increase nutrition (gradually)Feed pregnant ewe lambs separatelyEncourage daily exerciseMinimize stressVaccinate for CD‐TManage periparturient

OverfeedUnderfeedStress eweIntroduce new animalsChange groupingsLeave rams inManage periparturient

egg riseFeed a coccidiostatShear or crutch ewesPrepare facilitiesGather/inventory supplies

Leave rams inWorry

Thank you for your attention.

Lambing should be fun!

Any questions?

Susan [email protected]