SUSAN SCHOENIANSheep & Goat Specialist

University of Maryland Extensionsschoen@umd.edu – sheepandgoat.com

It is customary to replace 20 percent of the flock (or herd) each year.

Reasons for culling % of ewes

Age 55.6

Failure to lamb 7.7

Teeth problems 7.6

Hard bag syndrome 7.1

Mastitis 6.7

Poor mothering 4.7

Other 3.7

Chronic weight loss 2.1

Economic issues 1.7

Other illness 1.2

Single births 1.1

Other repro problems 0.9

Death (5%) + Cull (15%) = 20%

A death loss of 4-6% is common. This figure may be skewed in small flocks.

USDA APHIS NAHMS (2014)

10 years

Who should be culled?

Females that • Have lost all or part of their udder function.

• Have oversized teats.

• Have pendulous udders.

• Prolapse their rectum or vagina (uterus?).

• Are chronically infected with hoof disease and/or fail to respond to treatment(s).

• Require frequent hoof trimming.

• Require frequent deworming.

• Have unidentified weight loss.

• Are unable to maintain their body condition.

• Are open (fail to get pregnant)

• Fail to meet minimum standards for structural correctness and soundness.

Who else should you cull?Females that• Lamb/kid late (fail to conceive during

first two heat cycles, 34-42 days).• Miss more than one breeding

opportunity in accelerated birthing programs.

• Fail to conceive as ewe lambs or doe kids (@ 7 to 9 months of age), if that is a goal.

• Give birth to small, weak offspring that are slow to suckle.

• Reject their offspring.• Wean poor quality offspring.• Fail to wean offspring.

• Have fleece defects or wool quality issues (wool emphasis).

• Fail to shed (hair sheep)• Fail to meet standards for breed

character (registered breeders).

Consider culling . . . Hmm.

Females that • Require any deworming.• Require any hoof trimming.• Experience dystocia

(difficult birthing, esp. ringwomb).• Have singles more than once.• Miss breeding opportunity in

accelerated birthing scheme.• Sero-positive females for diseases

that you’re trying to eradicate (CAE, OPP, Johne’s, CLA).

• Are over the age of 6 (?)

• Have bad temperaments.• Are fence jumpers and escape artists

(mostly goats).

You have a choice.You can raise or purchase your replacements.

Raise replacements

• Closed flock/herdBetter biosecurity

• Can breed for traits that are most important to you.

• Can manage replacements the way you want to.

• May be cheaper to raise than purchase replacements.

Purchase replacements

• Can breed all of your ewes or does to a terminal sire.– Superior market lambs/kids

– No risk of inbreeding

– Fewer ram/buck purchases

• Can purchase replacements from farms that specialize in their production.

Percentage of females required to produce replacements

• Depends upon replacement rate and lambing/kidding percentage (# lambs/kids raised per female exposed)

Flock size # needed Lamb % ♀ lambs % flock

100 20 80 40 50

100 20 100 50 40

100 20 120 60 33

100 20 140 70 29

100 20 160 80 25

100 20 180 90 22

100 20 200 100 20

Breeding for replacement

• It is generally recommended that the top ~30% of the flock be bred for replacement.Example: Polypay x Polypay

• The other ~70% of the flock can be bred to a terminal sire for market animal production.Example: Suffolk x Polypay

• An alternative is to use dual-purpose breeds in a rotational crossbreeding system.Example: Kiko x Boer x Spanish

I make market lambs.

I make replacement ewe lambs.

Sires of replacement females

• Desired breed or breed cross.

• Breeds and individuals that excel in maternal and fitness traits.

• Desired coat or wool type.

• Desired level of reproduction.

• Desired level of fitness.

Selecting replacement femalesNeed to select replacements that suit production system and intended markets for progeny.

1. Visual appraisal2. Performance3. Genotype or

serotype

Visual appraisal

• Establish minimum standards for structural correctness and soundness.*– Feet and legs– Teats– Testicles (SC)– Mouth - bite - teeth– Conformation– Hoof growth and morphology– Shedding (hair sheep)

• Do not keep or sell animals with known genetic defects or disease issues (e.g. abscesses, hernia).

*Standards may be higher for seedstock producers and show flocks/herds.

Performance evaluation• Select animals that are genetically

superior for traits of economic importance to your enterprise.

Estimated breeding values (EBVs) Adjusted weaning weights

– Raw data• Weaning weights• Post-weaning weights• Carcass measurements• Wool measurements• Milk production• Fecal egg counts

– Subjective scoring systems• Birthing ease• Mothering ability• FAMACHA© score• Body condition score (BCS)• Hoof growth and disease status

Genotype

• Scrapie resistance

• Spider syndrome

• Hairy lamb syndrome

• OPP susceptibility

• Alpha S1 Casein

Serotype

• OPP

• CAE

• Johne’s disease

• Caseous lymphadentitis

Management of replacement females

• Identify early and separate from mature ewes and market lambs.

• Feed for moderate growth; frame more important than fat.

– May need to prevent winter born (creep fed) lambs and kids from getting too fat.

– May need to supplement spring-born lambs and kids.

• Ensure exposure to parasites so they can develop immunity.

Breeding for the first timeLambs/kids (7-9 months) vs. yearlings (19 months)

PROS

• First year income $$$$$

• Greater lifetime production

• Potential to increase genetic

gain, if progeny are saved.

• Better mothers and milkers

next go-round.

• Ewe lambs/doe kids failing to

conceive can be sold as market

animals.

CONS

• Require better feed and

management than mature

females.

• Should managed as a separate

group from mature females.

• More likely to have problems as

compared to mature females.

• It “stunts” their growth [?]

Breeding ewe lambs and doe kids

• Favor early-born females; however, size is more important than age.

• Ewe lambs and doe kids should achieve 60-70% of their mature weight (avg. weight of 3-4 year olds) before being bred.

Mating ewe lambs and doe kids

• Mate ewe lambs and doe kids to males with same or smaller mature size.

• Avoid heavy fronted males and those that sire offspring with above average-birth weights.

• Mate ewe lambs and doelings separately from mature females.

• Use pen or small paddock for breeding (instead of big pasture).

• Consider breeding later than mature females, so feeding and management can be differed.

• Option of pregnancy scanning and selling those that do not conceive.

Management of ewe lambs and doe kids

• Manage as a group; (ideally) keep separate from mature females until they are joined for the second time.

• Ewe lambs and doe kids have different nutritional requirements as compared to mature females.

– Primarily, ewe lambs and doe kids need to consume more nutrient dense diets (i.e. higher percentage of energy/TDN/ME).

– Ewe lambs and doe kids are generally less competitive for feeder space.

• Feed according to NRC requirements.

Lambing yearlingsEwe lambs and doe kids bred to lamb/kid at 12-14 months of age.

• Reproductive rate varies by breed and flock.– Often have singles.– Many have twins.– Some have triplets.

• More likely to experience problems (but that doesn’t mean they will).

• Usually do not have as much milk as mature females (but that doesn’t mean they won’t have enough milk to feed their lambs).

• Feed according to NRC requirements.

• Consider weaning lambs early to allow them to rebuild their body reserves for second joining.

Your replacement females should be the best females in your flock/herd.

Thank you for your attention. Questions? Comments?

SUSAN SCHOENIANSheep & Goat SpecialistUniversity of Maryland Extensionsschoen@umd.edu - sheepandgoat.com

My “yearling house”