Exam One - Lab Questions Flashcards
What breed of dairy cows are kept by the University farm?
Holstein dairy cows have been the sole breed of choice by the University farm since the early 1990s.
Why aren’t there more than one breed of cows kept by the University farm?
This was when research began at the University so it was decided to use one breed in order to eliminate a potential confounding variable. Holstein is also a popular breed that produces a large amount of milk each day.
Approximately, how many cows are in the University milking herd at any one time?
There are approximately 475-500 total cows at the PSU dairy barns with about 200 of them being milking cows.
How many animals are simultaneously milked in the milking parlor?
Twenty cows are simultaneously milked with ten on each side in the milking parlor.
How much times does it take to milk the entire herd?
It takes about four hours to milk the entire herd at about 5 minutes per cow
What time is the milking done?
Milking occurs twice a day; once at 5:00 AM and again at 5:00 PM.
What is the production of milk per cow per day?
About 85 pounds of milk per cow per day is produced at the PSU dairy barns.
What is the production of milk per cow per lactation period?
When considering per cow per lactation, it is about 27,000 pounds each period.
What is a TMR?
TMR stands for total mixed ration. It is the feed that is given to the cows at different quantities depending on the cow. It is given at a 3-5% refusal with the leftover feed being given to the younger animals. TMR is composed of corn silage, roasted soybeans, cotton seed hulls, canola meal, candy meal, dried corn kernels, and liquid molasses.
When are antibiotics used to treat dairy cows?
Antibiotics are used to treat dairy cows when they are sick or when they are milked for the last time. Antibiotics are put on the teats after their last milking so they don’t get infected.
What controls are in place to assure milk containing antibiotics isn’t comingled with milk that will be sold?
The controls that are in place to assure milk containing antibiotics isn’t comingled with milk that is going to be sold are the Delvo test and the SNAP test. The Delvo test determines if a previously sick cow’s milk is okay to rejoin the rest of the herd’s supply; her milk can then be sold as normal. The SNAP test determines the presence or absence of antibiotics in large quantities of milk.
How does the University farm test the milk for mastitis prior to milking?
The University tests for mastitis by measuring the milk’s electrical conductivity and the CA mastitis test. The milk’s electrical conductivity increases 12-24 hours before the physical signs of mastitis; this is due to the fact that the cow is fighting off infection. There is an increase in sodium, an electrolyte, in the blood because of increased white blood cell production. The CA mastitis test uses a reagent to coagulate the milk. The thicker the milk signifies more severe mastitis. A culture of the milk is then taken and plated to identify the microorganism.
List the steps that occur from the time a cow comes into the milking parlor to the time she leaves the milking parlor and indicate the purpose of each step.
Milking process steps:
Worker puts on gloves to reduce any spreading of germs
Worker wipes off the teats to clean off any sand and the touch also signals to the cow it is time to milk
Worker uses the teat dippers to clean the udder and reduce the risk of mastitis
Worker strips the cow to check for mastitis by collecting a drop of milk from each teat
Worker wipes the cow’s teats dry because the suction will not be as effective if they are wet
Worker attaches the milking cups
Machine milks the cows
Worker removes the milking cups and cleans the udders with the teat dipper
What is the temperature of the milk when it is harvested from the cow?
The milk is at 108F, a cow’s normal body temperature, when it is harvested.
How soon does the milk need to be cooled to 50F after harvest?
The milk needs to be cooled to 50F within a few minutes it comes out of the cow to reduce microbial growth and spoilage. A half hour later the temperature is reduced even further to 38F.
List the activities conducted by the milk hauler from the time that they arrive at the milkhouse to the time that they leave the milkhouse.
Milk hauler - receiving steps:
The hauler checks how much milk is there and converts that value from gallons to pounds
The milk is agitated to help evenly distribute the milkfat
What are the typical protein content, fat content, somatic cell, and bacterial counts for the PSU herd?
Typical content for the PSU herd: Protein: 3.1% Fat: 3.7% Somatic cell: 100,000 Bacterial count: 1000-2000 CFU
Is milk production homogenous throughout the year? If not, explain the highs and lows in seasonal milk production.
Milk production is generally homogenous throughout the year. It does decrease in the summer because the cows can get too hot. If they’re too hot, they will not want to eat so they won’t produce much milk. Milk’s nutritional content is mainly affected by the cow’s feed.
