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Animal Science
Bovine Somatotropin - Bst
9
Agriculture
Undergraduate 1
11/12/2008

Additional Agriculture Flashcards

 


 

Cards

Term

The US Dairy Industry

 

 Trends?

 

Herd Numbers, Cow Numbers, Herd Sizes, Cow Milk Production

Definition
approx 9.4 million dairy cows in the US (95% Holsteins) with general trends of declining herd numbers, declining cow numbers, increasing herd sizes and increasing per cow milk production; approximate trend is increase of 250 pounds of milk per year per lactation
Term

Somatotropin (ST)- growth hormone (GH);

 

Produced where?

 

how many amino acids?

Definition
a protein hormone (191 amino acids) produced in the pituitary;
Term

Effect on lactation

 

first established by who?

 

GH could increase milk production up to how much?

 

where to get GH?

Definition
first established by a Russian scientist (G. Asimov) in 1937 that crude pituitary extracts injected into cows would increase milk production; in the 1940's the active ingredient of this pituitary extract was isolated and named somatotropin; during WW II the British hoped to extract GH at slaughter houses to increase milk production - but it wasn't worth the effort (increase in total milk .05%); later work through the 70's showed that daily injections of GH could increase milk production by up to 50%; PROBLEM - Where to get enough GH? ANSWER - Biotechnology.
Term

rBST - recombinant bovine somatotropin

 

Developed by who?

Grow in what kind of bacteria?
Trade name?

Definition
developed by Monsanto & Genentech in 1981; isolate the naturally occurring bovine GH gene from cow cells, insert (recombine) the BST gene into bacterial DNA (E. coli), allow the bacteria to grow and make BST (even though E. coli know nothing about GH), kill the bacteria and harvest the microbially produced cow hormone, marketed under the trade name, Posilac
Term

rBST & lactation

 

daily injection can increase milk production between ______ %

 

change in milk composition?

 

cows will not respond to rBST if ______ or ______

 

is there evidence of increased incidence of metabolic disorders?

Definition
rBST injection on a daily basis can increase milk production between 16% to 20% over noninjected cows; no change in milk composition; cows will not respond to rBST if they are in poor condition or are being poorly fed; calving interval is a little longer in rBST treated cows; no evidence of increased incidence of metabolic disorders (e.g., ketosis)
Term

Results of a typical rBST trial

 

Feed in (Mcals)

Milk Out (kg/day)

Milk/Feed ratio

Without BST

34.1

 

 

With BST

 37.8

 

 

Definition

Results of a typical rBST trial

 

Feed in (Mcals)

Milk Out (kg/day)

Milk/Feed ratio

Without BST

34.1

27.9

.82

With BST

37.8

37.3

.99

Term

Economics in BST

 

Benificial to what kind of dairies?

 

Flexible?

 

How many days to see response?

 

Disadvantage?

Definition
BST administration should enhance profitability to the dairyman (over the cost of the hormone); BST should also be universally beneficial to small and large dairies alike - it requires no additional capital expenditures, just a needle & syringe; it is a flexible management tool - you can use it when you want & when feed and milk prices make it favorable; BST is almost like a 'light switch' - takes only 2-3 days to see a response from injections; Disadvantage - additional labor of injection
Term

The Consumer

 

Why don't people want to buy 'Growth Hormone' milk?

Definition
obviously, consumers don't like the sound of adulterated milk - a product where the sales appeal is based on its wholesomeness and nutritional value;
Term

will drinking BST milk cause you to grow into a basketball player?

 

Already in cow's milk, but how much?

 

BST level the same in the milk of rBST treated cows is at the same level as untreated cows?

Why or why not?

 

BST acts how?

 

What is IGF?

Definition
1) BST is already in cow's milk; if it's in cow's blood it's in cow's milk (but at very low levels (2 parts per billion)
2) BST levels in the milk of rBST treated cows is at the same level as untreated cows - why? BST does not act on the mammary gland (in fact, there are no GH receptors on the mammary gland)
3) BST acts by sending a message to the liver; the liver then makes proteins called IGF's (insulin-like growth factors) and it is the IGF's that the mammary gland responds to and are put out in high levels in the milk; BUT IGF's are protein and when we drink milk we digest the IGF's just like any other protein - so NO, drinking milk from BST cows will not cause you to grow upwards of 7 feet tall.
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