Udder Health in Does and Ewes

Angela Black, DVM, PhDDepartment of Animal and Avian Sciences

University of Maryland

Udder Anatomy3. Lateral suspensory ligaments4. Mammary lymph nodes5. Medial (middle) suspensory

ligament.

The suspensory ligaments provide the support for the gland and surrounding tissues.

Udder Anatomy

Udder Anatomy

• Udder should be held “high and tight” to the belly wall and above the level of the hocks during lactation.

• Producers should select against pendulous udders

• More likely to be damaged (bruising, lacerations)• More likely to develop mastitis• Difficult for lambs/kids to nurse

Udder Conformation

Udder Conformation

Udder Conformation

Inside the Udder

• Multiple gland lobes in each half of the udder.• These drain into the milk ducts.• Ducts coalesce into the gland cistern.• Drains into the teat cistern.• 0.5-1.0cm streak canal.– Important barrier to protect the udder from

infection.• Dead skin cells• Muscular teat sphincter

Anatomy of the Mammary Gland

Teat Anatomy• Teats can be classified as:– Clean • Single, normally shaped teat with one opening.

– Functional• Ability to produce and excrete milk

– Nonfunctional– Supranumeray (extra)– Split, Cluster, Fishtail– “Weeping”• Dairy breeds – milk secreting tissue in the wall of

the teat. Hands may get wet during milking, may see cyst filled with milk on teat.

Teat Anatomy

Abnormal Teat Anatomy

Teat Anatomy

Teat Anatomy• Pay attention to teat anatomy in breeding females and males

(can pass this on to his daughters).• Producers should select against:– Abnormal teats– Extra teats (depends on breed)• Serious disqualification in dairy breeds• Should never surgically remove them in registered or

purebred animals..• Boer goat breed allows 2 teats per side, allows split teats.• Can cause problems with nursing, • Can interfere w/ milking equipment.

Milk Volume/Composition• Sheep– 7.6% fat– 6.2% protein

• Goats– Average about 4% fat, can be as high as 6.9% in some

breeds.– Average of about 3% protein– Smaller fat globules– Higher proportion of short-chin fatty acids

• Compared with cows and goats, sheep milk is higher in fat, protein, caseins and other solids, but lower in volume.

• Miniature breeds – tend to produce less volume but milk is higher in fat and protein.

Late Gestation• Ewe/Doe must be fed a high quality diet at this point:

– Limited space in the abdomen for roughage– Sufficient protein and energy to produce colostrum and later, milk.

• Young ewes/does may not develop much of an udder before giving birth

• A couple of weeks before the due date, examine the teat ends for thick, waxy droplets indicating the presence of colostrum in the udder.

• If it is not there, does not mean that colostrum is not present.• Do not express the colostrum at this point.• If there appears to be a lot of this thick, creamy/golden colored

liquid leaking from the teats, be aware that you may need to supplement the lambs/kids with colostrum.

Immediate Postpartum Period• If the udder is over full or unbalanced, enough colostrum

should be stripped out to make suckling easier for the neonates.

• This colostrum can be tube fed to weak or slow to nurse lambs or kids or can be frozen in 240 ml (1 cup) quantities for later use in other lambs or kids.

Immediate postpartum period

• During pregnancy, there are waxy plugs inside the teat canals to help keep colostrum from leaking out and bacteria from getting in.

• May need to express a few drops of colostrum out of each teat to be certain that these plugs are out.

Lactation

• Milk “comes in” about 24-72 hours after birth.• Peak production occurs within 2-3 weeks of parturition.• In non-dairy breeds, production declines rapidly to a low 8-10

weeks after parturition.• Feed intake is generally the most important limiting factor

affecting milk production.• Underfeeding energy to ewes in late gestation and early

lactation results in higher death rates in lambs/kids.• Underfeeding protein in late gestation can result in reduced

or delayed colostrum production.

Udder Edema• Presents as mammary gland swelling• Common in recently freshened does or ewes.• Need to differentiate between edema and mastitis• Edema

– Normal milk– Usually resolves without treatment in newly freshened animals– Can be caused by significant internal parasitism

• Mastitis– Udder is either hot or cold to the touch– Painful to palpation– Abnormal milk (color, odor)– Animal may have fever

Asymmetric or Uneven Udder

• If animal is born with it, unbalanced suspensory ligaments.• Acquired– Uneven milk production• Side with less milk production may have subclinical

mastitis, causing lambs to preferentially nurse the healthy side.• If this is a herd-wide problem in a dairy herd, could be due

to asymmetric placement of milking claws from the side leading to different milk production rates.• May be fibrous tissue in one or both halves caused by

previous mastitis or trauma. This may cause a “Bind Half” – one side that does not produce milk.

Blind Half

• Mammary gland appears atrophied and no milk can be expressed.

• Severe damage to the gland associated with mastitis or trauma can result in fibrosis of the glandular tissue and loss of function.

• May resolve by the next lactation or may be permanent.

Hard Bag• Accumulation of fibrous tissue in the udder.• Replaces milk-producing tissue and results in lamb starvation.• Udder will appear full but has little or no milk.• Udder feels hard. • Can be associated with previous severe mastitis, Ovine

Progressive Pneumonia (OPP), Maedi visna, Caprine Arthritis & Encephalitis virus.

• Animals with persistent, lumpy bags should be culled.

Common appearance of udder with fibrous tissue masses

Hard Milker

Small streak canal limits flow of milk• Genetically small streak canal• May be due to trauma/irritation and consequent scarring

of the teat end.

Primary cause should be determined before breeding the animal.

Can be treated w/ surgical enlargement of the streak canal opening• Could result in permanent leakage• Increased chance of mastitis

No milk (Agalactia)

• Absence of milk in a lactating animal • Most common reasons– Systemic disease leading to reduced feed intake• Pregnancy toxemia, etc.

– Mastitis

Insufficient Milk• A small bag doesn't mean she doesn't have enough milk. – First time mothers will often not develop a large udder the

first lactation• Colostrum will not fill the udder the way milk will later.• Remember that milk “comes in” over a 24 to 72 hour period

after birth. • Oxytocin will stimulate "let down” of milk, but will not increase

production. Do not give it in the first 24-48 hours after birth unless it is for retained placenta.

Insufficient Milk

• How are the lambs/kids?– If the babies are warm, alert, nurse normally, maintain or

gain weight and are not in any distress, ewe is probably producing enough for them.

– If the babies are weak from the start, they may not nurse enough to stimulate sufficient milk production. You may need to milk the mother to increase production.

– If the babies are constantly trying to nurse but eventually become cold, weak, lethargic, dehdyrated or lose weight (more than the minimal amount expected within 24 hours of birth) consider the following:

Insufficient milk• Illness in the ewe such as pregnancy toxemia, retained

membranes, mastitis, etc.• Nutrition:

– Insufficient energy– High quality forage should be available 24/7 to new mothers.– Insufficient protein – should be (16-18%), – vitamins/mineral

• Parasites – milk production requires blood. Anemia reduces milk production.

• Healthy rumen microflora, control acidosis.• Lots of clean, fresh water

Precocious Udder• Mammary gland development and milk production occurs

without breeding or is excessive for the stage of gestation in a bred animal.

• Most common in dairy does from high producing genetic lines.

• Generally not cause for concern but should evaluate for pain, heat, texture of udder (should be soft, pliable)

• If true precocious udder, do not milk. – The keratin plug protects the streak canal, prevents mastitis– Will encourage milk production to continue

“Nell”• 2 yr old purebred Nubian Doe• Never exposed to a buck.• Pastured with a flock of sheep that lambed in

March/April of 2015.• In May, she developed a full udder, with milk. • No mastitis, no problems• Dried up about 4-6 weeks after we weaned

the lambs.

Nell

Teat lesions• Lacerations– Lambs/kids with sharp teeth– Other animal stepping on udder– Clean with Chlorhexadine or Betadine scrub and warm

water– Apply a disinfectant ointment or spray to create a barrier

to infection– If severe, may need to take lamb/kid off dam.

• Blisters/”sores” – – Look carefully at the lamb/kid’s mouth/lips for similar

lesions – possibly Orf (contagious ecthyma)

Mastitis• Infection of the mammary gland• Clinical

– Udder is abnormal• Swollen• Hot, red• “hard” or lumpy• Painful to touch

– Milk is abnormal • May be blood tinged or yellow• Texture may be thick, “lumpy”, or very watery• May have a foul odor• Lamb/kid refuses to nurse

– Animal may be visibly ill• Fever• Depression• Off feed

Clinical Mastitis

• Mild clinical mastitis Abnormality in the milk such as flakes, clots, and a watery or other unusual appearance. Udder may be swollen, hot or sensitive.

• Severe clinical mastitis Hot, hard sensitive udder, quite painful to the ewe. The onset is sudden and the ewe may become ill showing signs of fever (105° -107° F), rapid pulse, depression, weakness and loss of appetite.

• Chronic mastitis -A persistent udder infection exists most of the time in the subclinical form occasionally can develop into the clinical form before returning to the subclinical. The results are hard lumps in the udder from the "walling off" of bacteria and the forming of connective tissue.

Most common pathogens that cause mastitis

• Staphylcocci aureus is most prevalent• Mannheimia haemolytica• Coagulase-negative staphylcocci, • Pasturella spc.• E. coli and Klebsiella

Mastitic Udders

“Blue Bag”• Severe mastitis that eventually results in gangrene of the udder• Udder becomes dark red, hard and then turns blue. • Female often must be euthanized.• Affected gland will not be functional, if the animal survives.• Generally requires gangrenous tissue to be surgically removed.

Blue Bag

Mastitic Milk

Mastitis

• Subclinical– Most common in small ruminants.– Significant cause of reduced milk production and

increased bacterial counts or SSC in small ruminants.

– Animal, udder generally appear normal– May start as clinical and progress to chronic,

subclinical.

Mastitis Treatment

For all cases:• Isolated animals suspected of having mastitis• Keep affected halves stripped out.• Lambs/kids generally won’t nurse mastitic milk. May need

supplementation until resolved.

• Mild clinical mastitis– If mother appears normal other than the affected mammary

gland, intramammary infusions may be enough.– Consult with your veterinarian to determine the most

appropriate treatment.– Note drug withdrawl times!!

Mastitis Treatment

• Severe clinical mastitis– Mother shows signs of illness such as fever, off feed,

depressed attitude.– Consult with your veterinarian to determine the best

treatment.– Will likely include both intramammary and systemic

(injectable) antibiotic as well as antiinflammatory treatment.

• If very severe and unresponsive to other therapy, may need to amputate teat if value of animal or situation warrants.

• Again, pay attention to drug withdrawl times, especially for dairy herds.

Mastitis Prevention

• Hygiene– Clean, dry bedding/environment

• If lambs/kids are not nursing well, need to manually milk to prevent mastitis.

• Dairy operations– Teat/udder hygiene– Decontamination of equipment– Cull animals with subclinical infections, or always milk

last.– Do not feed infected milk to kids/lambs

Mastitis prevention at weaning

• Cut out all grain 3-5 days prior to weaning and switch to a lower quality forage to decrease the amount of milk being produced.

• Reduce all feed 12-24 hrs prior to weaning.

Questions?