| Term | Definition |
| Mammary Glands | - Cow: 4 Glands and 4 teats
- Sheep and goat: 2 glands and 2 teats
- Mare: 4 glands and 2 teats/channels
- Sow: Up to 20 glands and 10-14 teats on 2 rows |
| Mammary Gland Function | - Provides nutrition for offspring
- Provides passive immunity to offspring |
| Colostrum | - Normally needed withing the first few hours
- has nutrients and antibodies (immunoglobins)
- Most produced before parturition and stops at soon/ after parturition |
| Colostrum Composition | Has higher amounts of:
- Growth factors
- Immune factors
- Nutritional factors |
| Mammary Gland Structure: Alveoli | - Secretory tissue of mammary gland
- Made of millions of grapelike structures |
| Mammary Gland Structure: Gland Cistern | Large collection area in udder |
| Mammary Gland Structure: Teat Cistern | Collection area in teat |
| Mammary Gland Structure: Streak Canal | Passageway for milk out of teat (1cm) |
| Alveolus | Release of oxytocin at onset of milking stimulates the contraction of myoepithelial cells surrounding the alveoli |
| Secretory (epithelial) Cells Function | - Absorbs nutrients from bloodstream
- Make milk components (fat, lactose, protein)
- Transport milk into lumen of alveoli |
| Mastitis | Inflammation of the mammary gland
Cause- Microorganisms invade udder, multiply, and produce toxins |
| Subclinical | - No symptoms
- Increased SCC
- Bacteria
- Milk Loss
- Reduced quality
- Compositional Changes |
| Clinical | Visible symptoms
- Flakes/clots
- Abnormal milk
- Swelling
- Pain, heat, redness
- Fever
- Appetite loss
- Depression, etc. |
| Peracute | Most severe, could lead to death |
| Somatic Cell Count | - <200,000 cell/mL=favorable
- some research says too little SCC can cause mastitis as well
- <50,000=pretty normal |
| SCC Legal | - U.S = 750,000 cells/mL BTSCC (that's bad ya'll)
- Canada = 500,000 cells/mL
- EU = Limit: 400,000 cells/mL (export) |
| Contagious Mastitis Pathogens: Staphylococcus Aureus | - Heifers may calf while having it
- most common
- Repro tracts and nasal passageways can be carriers
Common treatments:
- Sell cow
- Try Dry treatment (doesn't normally work) |
| Contagious Mastitis Pathogens: Control | Prevention:
- Improved Milking procedures
- Milk clean, dry teats
- Keep liner slips minimum
- Dry treat all cows
Eliminating Infection:
- Treat all cows at drying off with antibiotic products for DCT
- Cull chronically infected cows |
| Contagious Mastitis Pathogens: Streptococcus Agalactiae | Source: infected udders
- Spread: cow to cow (during milking)
- Chronic; subclinical
- Lack of control = high BTSCC
- Can be eradicated |
| Environmental Mastitis Pathogens: Coliforms | - E. Coli
- Klebsiella
- Enterobacter |
| Environmental Mastitis Pathogens: Environmental Streptococci | - Strepto. uberis
- Strepto. Dysgalactiae |
| Environmental Mastitis Pathogens: Enterococcus spp. | - Enter. faecium
- Enter. faecalis |
| Environmental Mastitis Pathogens | Source: Manure, bedding, where cows congregate
New Infections:
- between milking
- early and late dry periods
- hot, humid weather
Duration:
- 60-70% last <30 days
- Clinicals: 50-80% |
| Traditional Mastitis Control | - Hygiene
- Milking Management
- Dry Cow therapy
- clean, dry environment
- enhanced resistance: coliform vaccine- dry off, mid-dry, and calving
micronutrient nutrition- selenium, vit. e, copper, zinc |
| Milking Procedures | 1. Dip: clean
2. Strip: Checking Milk
3. Dry
4. Apply: Milking machine
5. Dip: clean |
| Pre-Dip | Germicidal teat dip reduces environmental mastitis by 50% |
| Environmental Control | 1. Bedding (Straw, Sawdust, Compost Bedded Pack, Sand [ideal])
2. Manure Removal
3. Clean ,Dry environment (keep dry and out of mud)
4. Reduce exposure to pathogens |
| Factor Affecting Milk Production | 1. Breeding, genetics management
- nutrition and feeding
- sanitation
- mastitis
2. Heat stress
3. Requirements of offspring
4. Age, Parity
5. # of offspring |
| Milk Secretion | Oxytocin stimulates milk "letdown"
- causes contraction of myoepithelial cells around alveoli (45-90 sec after stimulation) |
| Milk Secretion Hormone | Prolactin and Growth Hormone (BST)
- stimulate and increase milk production in alveoli |
| After Birth | 1. Digestive tract increases {hypertrophy} (especially liver)
2. Calcium and Phosphorous mobilized from bone
3. Adipose tissue=mobilized
4. Muscle protein reserved=mobilized
5. Increased gluconeogenesis (pathway by which glucose is formed) |
| BST (Bovine Somatotropin)/(Bovine Growth Hormone) | - Higher milk production (.5-1.5 gallons a day
- Requires increased health management
- Naturally produced in cows and only active in cattle
- 90% destroyed in pasteurization
- Digested as protein in humans
- Public scared of BST |
| Raw Milk | Not pasteurized or homogenized
- CDC and FDA strongly against it
Cons:
- E. Coli O157:H7
- Listeria
- TB
- Salmonella |
| Milk Fever (Parturition Paresis) | - Metabolic Disorder (low levels of calcium in blood)
Symptoms:
- Muscular weakness, drowsiness
- Cow goes down and can't get back up
- Treatable if detected early
untreated may go into shock and die |
| Ketosis | - Metabolic disease'
Energy demands exceed energy intake = neg. energy balance
- Formation of ketones during fat metabolism
(acetone instead of acetic acid) |
| Ketosis Symptoms | - Reduce milk yield
- Weight loss
- Reduced Appetite
- Dull coat
- Acetone smell to breath/milk
- Fever
- Nervous signs: excessive salvation, licking, aggression, etc. |
| Dairy Production | 1. California
2. Wisconsin
3. Idaho
32. TN |
| Holstein | - Originated in holland
- Largest: 1,500-2,200lbs, 58'' tall
- Black and white
- Average production: 23,791lbs milk/lactation
9.7 gallons/day 3.7% fat
- 90% of daily producers milk Holsteins |
| Jersey | - Originated in British Channel; Island of Jersey
- Smallest: 880-1,100lbs
- Average Production: 17,302 lbs. milk/lactation
7 gallon/day 4.8% fat
- Valued for high quality butterfat in milk
- Fawn color: light tan -almost black |
| Brown Swiss | Huge but can't produce as much as Holstein
almost looks like a beef cattle |
| Guernsey | - Mid-size
- Very docile
- frail mentally and physically
- Don't really have the "will" to live |
| Ayrshire | - Ireland
- Really high longevity
- A bit of an attitude ( like a sassy mare) |
| Ideal Dairy Type | 1. Tall Stature
2. Angularity
3. Long, lean neck
4. Defined milk veins
5. Strong feet and legs
6. Level rump |
| Economically important traits in dairy cattle | - High milk production
- Longevity
- Reproductive Performance
- Milking ease
- Quiet disposition |
| Dairy Herd Improvement (DHI) | - Nearly 1/2 of all U.S dairy cattle enrolled
- Includes national database that is utilized for genetic evaluation
4 common data collection procedures
1. Supervised
2. Partially supervised
3. Owner conducted tests
4. Supervised electronic test |
| Pasteurizing and Homogenized | Pasteurize:
- Heating milk at 161 F
Homogenized
- Intense pressure (centrifuge) to break down fat into multiple particles |
| Milk Safety Timeline | - 1864: Pasteurization : louis Pasteur
- 1871: Refrigerated rail car
- 1875: Silos=invented (uni. Illinois)
- 1895: 1st commercial milking machines available |
| Dairy Trends pt. 1 | - U.S dairy farms = decreased; Not enough money, people don't want to take over business
- U.S dairy cow pop. = decreased then increased; lots of cows just on fewer farms |
| Dairy Tends pt. 2 | (2) - U.S Milk Production = Increased; Bigger farms and more cows, increase in health management
- U.S Consumption (Fluid) = Decreased; more options now, now we got so much w=milk where will it go |
