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Archived Food and Health Publications Archived USU Extension Publications

1999

Bovine Somatotropin in Milk

Charlotte P. Brennand PhD Utah State University Extension

Clell V. Bagley DVM Utah State University

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Part of the Animal Sciences Commons, Food Processing Commons, and the Nutrition Commons Warning: The information in this series may be obsolete. It is presented here for historical purposes only. For the most up to date information please visit The Utah State University Cooperative Extension Office

Recommended Citation Brennand, Charlotte P. PhD and Bagley, Clell V. DVM, "Bovine Somatotropin in Milk" (1999). Archived Food and Health Publications. Paper 32. https://digitalcommons.usu.edu/extension_histfood/32

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UTAH STATE UNIVERSITY COOPERATIVE EXTENSION FOOD SAFETY FACT 8UEET m1888 FOOD SAFTBY SBRIBS by Charlotte P. Brennand, PhD Clell V. Bagley, DVM Extension Food Safety Specialist Extension Veterinarian Bovine Somatotropin in Milk What is Bovine Sources of BST/BGH Biotechnology Somatotropin? production of BST Early research efforts used crude extracts from bovine pituitary Bovine Somatotropin (BST), The genes responsible for pro­ glands. Although the treated cows also called bovine growth hormone duction of BST in cattle were iden­ increased their milk production, the (BGH), is a hormone produced by tified in bovine tissue cells; they amount of available BST was too the cow's pituitary gland. It, like cause the pituitary cells to produce limited for commercial use. other hormones, is produced in small the biological product BST. These Biotechnology research re­ quantities and is used in regulating genes were isolated and inserted into ceived the impetus to produce hor­ metabolic processes. In the early a specific bacteria as part of a plas­ mones using genetically engineered stages of a calf's development, it mid, with gene splicing. As these bacteria because of our need for acts as a growth hormone. During altered bacteria replicate, the new insulin. Insulin is also a protein lactation, it serves to mobilize body genes are also replicated and passed hormone. The insulin isolated from fat to use for energy and diverts feed along to all new bacteria. The pres­ the pancreas of animals IS active in energy more toward milk produc­ ence of these genes causes the bac­ man when given by injection and tion than for tissue synthesis. terial cell to become a little "manu­ was the source ofinsulin for diabet­ BST is a protein hormone like facturing plant"which produces BST ics for many years. In the early insulin, not a steroid hormone like in large quantities. Eventually the 1980's, biotechnology made it pos­ the sex hormones and cortisone. bacterial cells are killed and re­ sible, through use of recombinant moved, leaving the purified BST. DNA gene splicing, to produce in­ Why inject cows sulin from bacterial cells. Today with BST? almost all insulin used for human BST in milk injection comes from this manufac­ turing technique. The procedure There are four different natural BSThasthe potential to increase for production of BST is conceptu­ forms ofthe BSThormone,withjust the efficiency of milk production. ally identical. Biotechnology is also slightly different chemical struc­ Potentially 10-15% more milk can used today to produce human growth tures. The synthetic form of BST be obtained from each cow with a hormone to control dwarfism and cannot be distinguished in the milk cost of implementation of less than interferon to treat a form of adult from the natural form. All milk 5%. leukemia. BST is the first product contains minuscule amounts ofBST approved for use in food animals regardless ofwhetherfrom untreated through this technology. cows or cows treated with BST. It is not possible, through testing of the milk, to tell if the cow has been treated with BST. Effect of BST on humans

An early test of bovine growth hormone was as a possible treat­ ment for children suffering from hypopituitary dwarfism. Although the bovine hormone was injected in large doses, it did not affect the Insulin-like growth treated. All cows produce BST and children. An extract from human all milk contains BST. Protein, but­ pituitary glands was successful. factors terfat, vitamins, calcium and other There is not enough similarity be­ minerals remain the same. Natural tween human and bovine growth Insulin-like growth factors I and variations occur between cows, but hormone for bovine produced II are involved with growth hor­ these cannot be related to which growth hormone to cause desirable mones therefore they need to be treatment the cow received. Neither or undesirable effects in humans. considered. IGF-II does not increase is Flavor ofthe milk affected. Con­ BST is digested by humans just when cows are treated with BST; sumers are not able to pick out the like any other protein. Therefore, there is a slight increase in IGF-I. It milk from cows treated with BST as even if it were active in the human is higher in human milk than in milk comparedto milkfrom control cows. body, one would not obtain the from treated cows. If it were in­ active hormone by drinking milk or jected, IGF-I could be active in hu­ Why is the use of BST eating cheese. About 90% ofBST is mans. IGF-I is not destroyed during destroyed during pasteurization and pasteurization ofmilk, however the controversial? it is also denatured by processing for heat treatment used producing baby baby formula. formula does destroy this hormone. First, as a new technology, the After careful review, the Food It is also destroyed when milk or use of BST can cause apprehension and Drug Administration, World meat is cooked. Since it a protein, in some consumers. This in turn Health Organization, American it is digested by both adults and worries the processors and the milk Medical Association, American Di­ infants, and therefore is not consid­ producers. They don't want to deter eteticsAssociation, and the National ered a problem. dairy product consumption! Institute of Health have indepen­ Second, it may affect the dairy dently confirmed that dairy prod­ Composition of milk economy. More milk can be pro­ ucts and meatfrom BSTtreatedcows duced from the same numberofcows are safe for human consumption. from cows treated with resulting in an increased milk sup­ BST ply. Some dairymen worry about competition with herds which may be using BST. Economic pressures There are no differences in milk on the dairy industry will continue composition from cows treated with regardless ofthe availability ofBST. BST and from cows which were not

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Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, m1888 Robert L. Gilliland, Vice President and Director, Extension Service, Utah State University.