Transcript Silage
EXPLORING DAIRY ANIMALS AND DAIRY PRODUCTS OBJECTIVE 1: Understand the anatomy of dairy cattle and how they produce milk. Dairy cows take the food and water they consume and turn it into milk to feed their calves. The milk is also used by humans. A. Dairy cows must be fed properly in order to produce milk. 1. Dairy cows eat a total of 90 pounds of feed a day. • • 40 pounds of grain and hay 50 pounds of silage Silage- chopped plant material that has been allowed to ferment Silage may contain leaves, stems, grain heads, and other plant parts. Most silage is made from green, growing crops, such as corn, grass, or sorghum. 2. Cows also drink 25 to 50 gallons of water each day. 3. With this amount of food and water, a dairy cow can produce about 100 glasses of milk a day. B. Cows make milk in their udder. Udder- the pouch that hangs underneath the cow that contains the mammary glands. The udder is divided into four sections. Each section of the udder has a small tube called the teat that lets the milk out. Inside the udder are lumens that make small drops of milk. Once the lumens make enough milk to fill up the udder, milk comes out of the teat when the cow is milked or when she feeds her calf. A cow’s udder can hold 25 to 50 pounds of milk. STRUCTURE OF A COWS UDDER Central Wall or Median Suspens ory Ligament Fine Membrane Between Quarters Alveoli Outer Wall or Lateral Suspens ory Ligaments OBJECTIVE 2: Explain how milk is processed for human consumption. There are many steps involved in getting milk from a dairy cow into the store. A. Milk must be properly collected from the cow. • Today in the United States most of the milking is done by milking machines. • With these machines producers can milk 100 cows in one hour. Fair Oaks farm: https://www.bing.com/videos/search?q=fair+oaks+farm&&view=detail&mid=2A53355B99006F3F830B2A53355B99006F3F830B&F ORM=VRDGAR Milking machines are placed on each of the cow’s teats and gently suck the milk out of the cow’s udder. The milk is then pumped into a large tank at the farm. A truck from the dairy company comes to the farm, tests the milk, and then takes it to the dairy to be processed. B. Milk must be safe for humans to consume. 1. At the dairy plant, milk is pasteurized. Pasteurization- milk is quickly heated to a high temperature and then quickly cooled. Why is this done? There are viruses and bacteria present natural in cows milk that can make humans sick & can cause milk to spoil quickly. Pasteurization KILLS the germs and bacteria. Homogenization breaks the fat globules in the milk into tiny particles. If this step does not take place, the fat or cream would sit on the top of the milk. After processing, the milk is poured into jugs and cartons to be sold in stores. The milk is never touched by human hands when it is in the plant, so it is one of the safest foods you can eat. OBJECTIVE 3: Describe dairy products and how they are made. Through many processes, milk is made into many different dairy products. A. Ice cream How it is made: Sugar and flavoring are added to milk and then frozen into ice cream. B. Cheese How it is made: Milk is allowed to sour and separate into whey and curds. Curds - the chunks that form in soured milk. These are the beginnings of cheese. Whey- the liquid that remains after the curds form. • The curds are separated from the whey & aged and flavored to make the cheeses you eat every day. C. Butter Butter is the cream, or fat, that is present in milk. How it is made: The fat is removed from the milk and churned or shaken into a solid form called butter. D. Yogurt Made by adding certain bacteria to concentrated, pasteurized milk. The milk is then heated at 110°F for four or five hours to allow the bacteria to grow. The smooth, custard-like texture that is formed is the result of the growth of the bacteria. Flavoring or fruit can be added to the mixture.