introduction to animal science lactation agr vet science 1-3-2012
TRANSCRIPT
![Page 1: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/1.jpg)
Introduction to Animal Science
LactationAGR Vet Science
1-3-2012
![Page 2: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/2.jpg)
Lactation
![Page 3: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/3.jpg)
Definition of Lactation The process of producing milk. Occurs specifically in the mammalian
species. Milk is the food source for the
nourishment of the young. Calcium and Phosphorus Protein Carbohydrates & Fat Vitamins and Minerals
![Page 4: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/4.jpg)
Milk Produced and secreted by the
mammary glands of the female. A liquid containing these major
constituents Water (88%) Triglycerides (Fat) (3.5 – 9.6%) Lactose (4 -5%) Protein (3 – 6%) Refer to Table 12-1 on page 260 in text
![Page 5: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/5.jpg)
Discussion of the udder and mammary gland is like the
chicken and egg discussion, where do we start first?
![Page 6: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/6.jpg)
Mammary Gland A milk secreting structure consisting of:
Teats (storage and delivery) Duct system Lobes of a secretory system
A modified sweat gland (sudoriferous gland) of the exocrine system
All a part of the total called the udder.
![Page 7: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/7.jpg)
Mammary Gland Development
Prenatal – Anatomical structures are present.
Birth to puberty – Structural growth is influenced by somatotropin (growth) hormone. Hormone produced for each species is similar to each other.
Puberty – onset of progesterone and estradiol hormones stimulate the growth of the mammary gland at a rate greater that prepuberty.
![Page 8: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/8.jpg)
Development Cont’d During gestation,
progesterone stimulates the lobule-alveolar development.
The lobule-alveolar are responsible for milk synthesis.
![Page 9: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/9.jpg)
The Mammary Gland
![Page 10: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/10.jpg)
Another View of the Mammary Duct
![Page 11: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/11.jpg)
An Udder
A complex organ made up of: A supportive system A secretory system made up of
epithelial cells (lubule – alveolar) A duct system for the storage and
conveyance of milk Blood, lymph and nervous systems
![Page 12: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/12.jpg)
Supportive System
![Page 13: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/13.jpg)
Anatomy and Physiology of the Udder
Anatomically, the udder hangs from the pelvis
Physiologically Supported by the median suspensory
ligament and the lateral suspensory ligaments on each side.
Connective tissue attaches the udder to the abdominal wall.
Connective membranes divide the udder into quarters or halves depending on species.
![Page 14: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/14.jpg)
Teat Structure
![Page 15: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/15.jpg)
Anatomy and Physiology of the Teat
Exterior portion or visible structure attached to the duct system of the mammary gland.
Limited storage capacity. Physiologically
Smooth muscle surrounded by skin (epidermal layer of tissue).
Circular muscle form a sphlincter at the base with a teat canal for milk flow or a wax barrier.
![Page 16: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/16.jpg)
Hormonal Activities Before, At and Immediately After Parturition
Related to Mammary Activity and Lactation
Prolactin Released from the anterior pituitary gland Initiates and maintains lactation
Progesterone and estrogen Decreases abruptly at parturition Lactogenesis begins with decrease
Oxytocin Released by the posterior pituitary gland Responsible for milk letdown from the
ducts of the udder
![Page 17: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/17.jpg)
Circulatory System Related to the Mammary
Gland
The primary aorta and the cranial epigastric artery provide blood from the heart to the arteries which provide to the udder and its milk producing components. External iliac artery External pudic or mammary artery Subcutaneous abdominal artery Perineal artery
![Page 18: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/18.jpg)
![Page 19: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/19.jpg)
Circulation from Udder to Heart
While arteries carry blood from the heart, veins carry blood back to the heart from the udder. Vena cava External iliac vein External pudic vein Subcutaneous abdominal vein
![Page 20: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/20.jpg)
![Page 21: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/21.jpg)
100 Days & 106 Days of Gestation
![Page 22: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/22.jpg)
Milk Production or Lactogenesis
Colostrum produced Stage I lactogenesis Specialized milk produced in the early days
following parturition to provide extra nutrients and immunology to the newborn offspring.
Contains immunoglobulins produced by the mother’s immune system. Antibodies are specific to mother.
Easily absorbed into the digestive tract for 2-3 days after birth.
Contains higher levels of milk proteins and lipids. Contains higher levels of Vit. A & D as well as iron
(note exception in swine)
![Page 23: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/23.jpg)
Feeding Orphans Colostrum
Use frozen colostrum from your farm
Old ice cube trays work well. Use oesapageal feeding
tubes to get young animals too weak to feed on their own.
Never feed young unless standing.
Allow them to “chew” down the tube, thus avoiding the wind pipe and drowning or causeing lung infections.
![Page 24: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/24.jpg)
Mares’ Waxing
![Page 25: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/25.jpg)
Lactogenesis Stage II The primary structures of the gland are the
alveoli. Milk is secreted by the secretory cells that
surround the outside of the lumen. The alveoli are spherical and are capable of
storing milk. The secretory cells are housed in the alveoli
and contain the necessary enzymes to produce the components of the milk.
![Page 26: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/26.jpg)
Practices to Encourage Oxytocin Production & Milk
Letdown
Wash and massage the udder prior the milking with dairy cows.
Maintain are routine in the milk shed. Play music to drown out unusual or
startling sounds. Play recorded sounds of sow’s nursing
to encourage other sow’s to letdown milk.
![Page 27: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/27.jpg)
Function of the Secretory Cells
To absorb the necessary precursors (nutrients) from the bloodstream.
To transform the nutrients into the lactate, fat, and protein of the milk.
To transfer the newly synthesized milk into the lumen of the alveolus.
To absorb minerals and vitamins from the bloodstream and are combined with the synthesized prior to discharge from the alveolus.
![Page 28: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/28.jpg)
Activities of the Alveoli Contains the milk produced by the
secretory cells. Arranged in lobules and drainage is
through a complex ductwork system. The ducts terminate at the teats into a
gland cistern. From the gland cistern, milk leaves the
udder through the streak canal of teat with relaxation of the sphincter of the teat.
![Page 29: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/29.jpg)
Another View of the Mammary Duct
![Page 30: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/30.jpg)
Milk Letdown Cont’d
Oxytocin from the pituitary gland acts on the specialized muscle cells called myoepithelial cells, which surround the secretory cells, causing them to contract.
Contraction squeezes the lumen of the alveolus. With milk discharge, the alveoli deflate allowing space for more milk to be produced.
![Page 31: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/31.jpg)
![Page 32: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/32.jpg)
Another View of the Mammary Duct
![Page 33: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/33.jpg)
Preventing Udder Infections
Infections of the udder are called mastitis. Reduce the incidence of mastitis by:
Maintain clean bedding for the female to lay on. Clean udders prior to milking. When using a milking machine, use automatic
teat cup releases. Avoid excessive energy immediately after
parturition causing excess milk to be released. Remove excess colostrum if necessary. Select females according to udder design.
![Page 34: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/34.jpg)
Desirable Udders to Select For
With sows, select females with distinct separation of teats and their “quarters”.
Note the top picture and compare it to the lower one. Which one will you select for?
![Page 35: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/35.jpg)
Ailments Associated with Mastitis
Metritis – uterine infections following parturition caused by bacteria moving up the female tract during parturition. Assisting at parturition using unsanitary instruments or hands and arms can lead to infections.
Agalactia – milk failure due to udder infections or the inability to letdown milk from the udder.
![Page 36: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/36.jpg)
Udder Placements Inguinal – cattle,
sheep, horses, pigs, dogs, cats, goats
Abdominal – pigs, dogs, cats
Pectoral (Thoracic) – pigs, dogs, cats, humans
![Page 37: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/37.jpg)
Udder Attachments Cont’d
![Page 38: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/38.jpg)
Lactation Curve Info
Basic curve
![Page 39: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/39.jpg)
Dairy Cow Milk Curve and Persistence
![Page 40: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/40.jpg)
Lactation Curve Info
Basic curve Persistence of lactation over time
![Page 41: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/41.jpg)
Dairy Cow Milk Curve and Persistence
![Page 42: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/42.jpg)
Lactation Curve Info
Basic curve Persistence of lactation over time Effect of multiple births
![Page 43: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/43.jpg)
Milk Production Rates of Twin Lambs (x) vs Single Lambs (o)
![Page 44: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/44.jpg)
Lactation Curve Info
Basic curve Persistence of lactation over time Effect of multiple births Differences between species
![Page 45: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/45.jpg)
![Page 46: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/46.jpg)
Lactation Curve Info
Basic curve Persistence of lactation over time Effect of multiple births Differences between species Differences within species with
different functions
![Page 47: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/47.jpg)
![Page 48: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/48.jpg)
Milk Involution Gradual decrease
in weight, volume, and productivity of milk from the udder.
![Page 49: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/49.jpg)
Major Components of Milk
Carbohydrates – lactose Protein Lipids Calcium
![Page 50: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/50.jpg)
Lactose Synthesized in secretory cells by combining
glucose with galactose. Glucose must come from the body of the cow
through the bloodstream. Propionic acid (VFA) is converted to glucose
by the liver. Acetic and Butyric are used to make milk fat
or simply oxidized and used as an energy source by the animal.
![Page 51: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/51.jpg)
Lactose Cont’d
A disaccharide which must be broken down in the s. intestine.
The enzyme, lactase, is responsible for the breakdown.
![Page 52: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/52.jpg)
Protein Primary protein in milk is casein. Casein makes up 80% of all the protein in milk. Casein proteins contain a negative charge due
to the phosphate ions held in association with the casein. Ca++ from the bloodstream combines with the casein protein and the phosphate.
Other milk serum proteins: Lactoglobulin, lactalbumin and immunoglobulins. Approximately 18% of the total protein present in milk.
![Page 53: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/53.jpg)
Protein Cont’d Immunoglobulins in the colostrum
provides high levels of protein for the newborns.
Provide passive immunity since the immunoglobulins are absorbed directly into the s. intestine. Closure of the gut usually occurs within the first 24 hours.
Milk content containing colostrum returns to normal in 3-4 days following parturition.
![Page 54: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/54.jpg)
Lipids Percentage and chemical makeup of fats in
milk vary between species. Primary lipids are:
Triglycerides Cholesterol Phospholipids
Fatty acids which make up triglycerides vary in length and degree of saturation. Fatty acids extracted from blood-borne
lipoproteins Produced by the mammary gland
![Page 55: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/55.jpg)
Lipids Cont’d
Mammary gland produces mostly saturated fats as a result unsaturated fats being saturated in the s. intestine. These are packaged into lipoproteins.
The precursor to the fatty acids synthesis in the mammary gland is acetic acid (VFA). It comes from the rumination of roughages in the rumen.
![Page 56: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/56.jpg)
Calcium Present in the milk because of its positive ionic
charge combines with the negatively charged protein ion.
High producing females of milk may undergo lower levels of calcium in the blood stream when high levels of protein are needed to be produced during periods of high milk production.
Milk fever or parturient paresis occurs as a result of the above.
![Page 57: Introduction to Animal Science Lactation AGR Vet Science 1-3-2012](https://reader035.vdocuments.net/reader035/viewer/2022081506/56649ce55503460f949b3284/html5/thumbnails/57.jpg)
BST – Bovine Somatotropin
Approved by the FDA in 1985. Somatotropin is a natural growth hormone
responsible for milk production and produced and released from the pituitary gland.
Naturally increases milk production. Synthetically produced BST increase production
an additional 10-20% with improved presistence. Safe for human consumption of the milk because
it is a protein and if present in the milk it would naturally be broken down in the human stomach.
Monsanto product originally observed at Cornell U.