Camelid Lactation & Care of the Newborn - Anatomy & Physiology

All camelidae are born in a relatively advanced stage of development and should be relatively active and capable of holding their heads up high as well as standing, nursing and walking unaided within a few minutes to one hour after birth.

Epidermal Membrane

• A unique characteristic of camelids is the development of an extra membrane of fetal epidermal origin called "the epidermal membrane".
  • Covers the neonate and is attached at muco-cutaneous junctions but does not cover the nostrils or mouth so there is little danger of suffocation.
  • Very friable and can be easily removed with only the slightest friction.
  • Close examination of this epidermal membrane is very helpful in evaluating prematurity and the degree of stress in the newborn.
    • In premature camelidae the membrane is firmly attached to the extremities, and in case of dystocia or prolonged birth, the epidermal membrane becomes yellow because of the increased defecation and even diarrhea of the fetus.

Normal Parameters

• The average normal birth weight ranges from 30 to 42 kg depending on species.
• The heart rate is usually very high at birth 80 to 120 beats, but respiration should be a regular 20 to 30 breaths per minute.
  • Signs of respiratory distress include open mouth breathing (gasping for air), or heavy breathing due to collapsed lungs, presence of fluids or choanal atresia.
• Normal body temperature varies from 37.5oC to 39oC but the newborn may show shivering during the first few hours after birth, which is quite normal.

Mammary Gland

• In the prepuberal and nulliparous females, only the small teats are visible as the mammary tissue does not develop until the end of the first pregnancy.
• At the peak of lactation, the udder has increased in size and shows well-developed venous drainage.
• The udder consists of four glandular quarters, each with its own teat.
• The left and right halves of the udder are separated from each other by fibroelastic tissue extending from the linea alba and prepubic tendon and a groove is generally visible between the left and right halves.
• The lateral aspect of the quarters is covered by tissue from the abdominal tunic and the caudal abdominal wall.
• The anterior and posterior quarters are independent but there is no visible separation between them and the teats
• Teats are directed cranio-ventrally and possess two openings.
• Conformation of the udder can change according to breed, age and stage of lactation.

Histology

• Each mammary gland consists of parenchyma, connective stroma, ducts and alveolar systems.
• The gland is made of several individual lobules separated by septa of connective tissue (interlobular connective tissue).
• The glandular units of the lobule, the alveoli or acini, are separated from each other by the intralobular connective tissue which projects from the interlobular connective tissue but there are no anastomoses between glands.
• The duct system begins with small intralobular ducts that enlarge progressively and each duct is lined by an epithelium resting on a distinct basement membrane.
• The duct epithelium is low, simple and secretory in the smallest intralobular duct but becomes columnar in the larger ducts.
• The secretory units, acini or alveoli, are small vesicles of unequal sizes that form the lobule-alveolar system.
• The epithelial lining of the alveoli (flattened to columnar epithelium) shows great variation according to stage of lactation and secretory activity of the gland.
  • In the non-lactating female, the number and size of alveoli per lobule decreases, the parenchymatous tissue regresses and the interalveolar space becomes filled with interstitial connective tissue.

Milk Composition

• Llama milk has a higher lactose content (6.5%) and lower fat content (2.7%) than milk from other domestic ruminants.
• Llama milk contains more calcium and less sodium, potassium and chloride but the concentration of trace minerals is similar to that found in bovine milk.
• Composition of milk is not affected by stage of lactation, lactation number or body condition score.

Suckling

• The suckling reflex is usually shown within the first 30 minutes.
• Camelidae are born agammaglobulinemic because of the lack of placental transfer of immunoglobulins.
• Rely exclusively on passive immunity absorbed from maternal colostrum for their protection against infection during the first weeks of their life.
• Colostrum absorption is possible during the first 24 hours of life, with the maximum absorption being achieved during the first 8 to 12 hours.
• Failure of passive transfer of colostral immunoglobulin is the major factor in neonatal mortality in alpacas and probably also in other camelidae.
• Newborn cria should receive 10% of their body weight in colostrum, preferably within the first 12 hours after birth, with half of this amount given in the first 6 hours after birth.
• Many factors such as cold weather or heat stress, lack of mothering, delivery by caesarean section and metabolic disturbances can can negatively affect the absorption of immunoglobulin.
• If the dam does not have enough colostrum, and no other camelid colostrum is available, then cow or goat colostrum may be used as a substitute.
• In normal circumstances, the calf is left with the dam once it has been determined that the dam is producing colostrum.
  • This is important because maternal bonding enhances absorption of colostrum.
• If the calf is not seen suckling by 3 hours after birth, then colostrum should be milked out and bottle-fed to the calf.
  • If the calf has a poor suckling reflex, administration of colostrum should be initiated via a stomach tume (as in lambs).
• Vitamin E-selenium preparations can be given intramuscularly to neonates born in selenium deficient regions.