AVS 101 1st Edition Lecture 14Milk Production90% of world’s milk comes from cows (222 million)10% from buffalo & goatEach cow produces enough milk for 50 people.150 billion lbs. produced in US.Factors influencing milk production in US- Modern dairy breeds- Cheese- Seasonal- Pasteurization –kills bacteria that causes T.B.- Mechanical refrigeration- Homogenization – fat particles broken down- Milking machine- Babcock Test (1892) – measures fat in milk- Whole milk – consumption down since 1975- Record keepingHeterosis (hybrid vigor)- Offspring of a cross can be better than either parentsFermented Dairy Products- Selected cultures of bacteria are added to make:- Buttermilk - Cottage cheese- YogurtDairy Products- Cream – 18% fat- ½ & ½ - 10-18% fat- Heavy Cream – 36% fatComposition of milk- 88% water- 8.6% SNF (solids not fats)- 3-4% milk fat- 4.8% lactose- 3.35% protein (casein)- All essential vitamins- High in calcium, low in ironImitation Dairy Products- Water, corn syrup, fats, protein from soybean, whey, lactose- Look for “REAL” symbolCheese- 400 different kinds/2000 names- Soft, semi-soft, hard, very hardBased on moisture- Cheese making involves coagulationCurdling Making cheese- Rennet – enzyme, thickener- Curd is formed- Liquid removed à whey- 100 lbs. milk à 8-16 lbs. cheese- Visuaappraisal of dairy cow- Mammary systemUdder, ligaments, veins, teats- Feet & legs- Body capacityBig rib cage- Mature sizeLong, lengthy- Correlated to milkproductionCulling- Removal of animal from a herdMilk- Perishable food- Medium for growing bacteria- Shelf life à 10-14 daysMilking facilities must:- Meet rigid sanitation standards and- FDA says “milk best controlled/monitored of all foods”Milk Sanitation (Board of Health)- All cows must be TB and Brucellosis-free- Water supply be safe & sanitaryGrade A Milk- Market milk- Cooled to 45 F (usually 38 F) or less within 2 hours after milking- Less than 100,000/ml in bacteria count- Less than 1 million somatic cell countGrade B- Less stringent- Manufacturing milkMilking machine- Essentially all cows in US are milked by machineUdder preparation- Stimulates milk letdown- Sanitize external teat – dry- High bacteria count in first few squirts – eliminate- Cow is milked out in 3-6 minutes- Post-dip – iodine or bleach solutionBacteria enter dilated teatMilk handling- Processing & manufacturingAll milk is pasteurizedHigh Temp Short Time (HTST) method161°F for 15 secondsUltra High Temp (UHT) à 280°F for 2 secondsMilk is sold….- Mainly through cooperative marketing associations- Or direct to consumer- Retail/plastic gallon
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