View source for Bovine somatotropin

{{short description|Peptide hormone produced by cows' pituitary glands}}
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[[Category:Livestock]]
[[Category:Dairy industry]]
[[File:Holstein dairy cows.jpg|thumb|250px|rBST is a product allowed only in certain jurisdictions and primarily given to [[dairy cattle]] by injection to increase milk production.]]

'''Bovine somatotropin''' or '''bovine somatotrophin''' (abbreviated '''bST''' and '''BST'''), or '''bovine growth hormone''' ('''BGH'''), is a [[peptide hormone]] produced by cows' [[pituitary glands]].<ref name="Brennand">{{cite web |author=Brennand |first1=Charlotte P. |last2=Bagley |first2=Clell V. |title=Bovine Somatotropin in Milk |url=https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1031&context=extension_histfood |access-date=6 March 2011 |website=Utah State University - Digital Commons}}</ref>  Like other hormones, it is produced in small quantities and is used in regulating metabolic processes.<ref name="Brennand"/> Scientists created a bacterium that produces the hormone somatotropin which is produced by the cow's body after giving birth<ref>{{cite book| last1=Robin|first1=Marie-Monique| isbn= 9781595584267| title=The Ethics of What We Eat: Why Our Food Choices Matter | year=2007 |publisher=New Press }}</ref>{{page number needed|date=October 2024}} and increases milk production by around 10 percent.<ref>{{cite book| last1=Singer|first1=Peter | last2=Mason| first2=Jim| isbn= 9781594866876| title=The World According to Monsanto: Pollution, Corruption, and the Control of the World's Food Supply | year=2010|publisher=Harmony/Rodale }}</ref>{{page number needed|date=October 2024}}

Recombinant bovine somatotropin (usually "rBST"), is a synthetic version of the bovine growth hormone given to dairy cattle by injection to increase milk production.

Controversy over its safety has led to it being banned in several countries, including the [[European Union]] since 1990, and Canada, Japan, Pakistan, Australia, New Zealand, and Argentina, as it has been found to increase health risks in cows. The [[Codex Alimentarius]] has not approved it as safe.

The [[Food and Drug Administration|FDA]] approved it in 1993, and required that any milk advertising that its cows were not treated with rBST include the disclaimer "The FDA has determined that no significant difference has been shown between milk derived from rBST treated and non-rBST treated cows".

==Synthesis==
After the biotech company [[Genentech]] discovered and patented the [[gene]] for BST in the 1970s,<ref name=Schneider>Keith Schneider. 10 June 1990. [https://www.nytimes.com/1990/06/10/magazine/betting-the-farm-on-biotech.html?pagewanted=all&src=pm "Betting the Farm on Biotech."]. ''the New York Times''</ref> it became possible to synthesize the hormone using [[recombinant DNA technology]] to create '''recombinant bovine somatotropin''' ('''rBST'''), '''recombinant bovine growth hormone''' ('''rBGH'''), or '''artificial growth hormone'''.{{citation needed|date=October 2021}}

==Industrial production==
Four large pharmaceutical companies, [[Monsanto]], [[American Cyanamid]], [[Eli Lilly and Company|Eli Lilly]], and [[Upjohn]], developed commercial rBST products and submitted them to the US [[Food and Drug Administration]] (FDA) for approval.<ref>Bijman, J. (June 1996), [https://web.archive.org/web/20020926093647/http://www.biotech-monitor.nl/2702.htm "Recombinant Bovine Somatotropin in Europe and the USA"]. ''Biotechnology and Development Monitor'', No. 27, p. 2-5.</ref><ref name="WHO">Bovine Somatotropin. Joint FAO/WHO Expert Committee on Food Additives Monograph [https://web.archive.org/web/20170518211121/ftp://ftp.fao.org/es/esn/jecfa/vetdrug/41-5-bovine_somatotropin.pdf]</ref>

Monsanto was the first firm to receive approval.{{Citation needed|date=December 2023}}

Other countries (Mexico, Brazil, India, Russia, and at least ten others) also approved rBST for commercial use.<ref name=Dobs>William D. Dobson. June 1996 [http://www.aae.wisc.edu/pubs/sps/pdf/stpap397.pdf The BST Case] {{Webarchive|url=https://web.archive.org/web/20200921122744/http://www.aae.wisc.edu/pubs/sps/pdf/stpap397.pdf |date=21 September 2020 }}. University of Wisconsin-Madison Agricultural and Applied Economics Staff Paper Series No.397</ref>

Monsanto licensed Genentech's patent,<ref name=Schneider /> and marketed their product as "Posilac".<ref name="Dohoo2003"/><ref name="Dohoo2003b"/> In October 2008, Monsanto sold this business, in full, to [[Eli Lilly and Company]] for $300&nbsp;million plus additional consideration.<ref name="urlEli Lilly to Buy Monsanto's Dairy Cow Hormone for $300&nbsp;million - DealBook Blog - NYTimes.com">{{Cite news|url=http://dealbook.blogs.nytimes.com/2008/08/20/eli-lilly-to-buy-monsantos-dairy-cow-hormone-for-300-million/ |title=Eli Lilly to Buy Monsanto's Dairy Cow Hormone for $300&nbsp;million – DealBook Blog |work=The New York Times| date=20 August 2008}}</ref>

==Banning==
{{cleanup section|reason=Should be part of section "Regulation" below.|date=December 2023}}
rBST has not been allowed since at least 2000 on the market in Canada,<ref name=autogenerated1/> or since 1990 in the [[European Union]] (EU).<ref name=eucelex/> Australia, New Zealand, Japan, and Argentina have also banned the use of rBST.<ref>{{Cite web|url=http://www.burrafoods.com.au/latest-news/food-safety-wins-out-on-gmo-bovine-growth-hormone-saga|title=Blog : Food Safety Wins Out on GMO Bovine Growth Hormone Saga : Burra Foods|website=Burrafoods.com.au|access-date=2019-03-05|archive-date=2 June 2019|archive-url=https://web.archive.org/web/20190602132534/http://www.burrafoods.com.au/latest-news/food-safety-wins-out-on-gmo-bovine-growth-hormone-saga|url-status=dead}}</ref>

The FDA,<ref name="fda.gov"/> [[World Health Organization]],<ref name=WHO/> and [[National Institutes of Health]]<ref name="NIH RBST"/> have independently stated that dairy products and meat from rBST-treated cows are safe for human consumption.

An EU report on the [[animal welfare]] effects of rBST states that its use often results in "severe and unnecessary pain, suffering and distress" for cows, and is "associated with serious [[Mastitis in dairy cattle|mastitis]], foot disorders and some reproductive problems".<ref name="ec.europa.eu">{{Cite book | title = Report on Animal Welfare Aspects of the Use of Bovine Somatotrophin | url = http://ec.europa.eu/food/fs/sc/scah/out21_en.pdf | date = 10 March 1999 | access-date = 16 January 2008 | publisher = The Scientific Committee on Animal Health and Animal Welfare, [[European Union]]. | url-status = dead | archive-url = https://web.archive.org/web/20080904003449/http://ec.europa.eu/food/fs/sc/scah/out21_en.pdf | archive-date = 4 September 2008}} <br />Note: According to the report, somatotropine, which is often used, is a misnomer as "<u>tropic</u> factors affect direction or extent of body movement while <u>trophic</u> factors affect growth". So the Commission uses the spelling somatotrophin.</ref>

==History==
{{Expand section|1=discussion of development efforts by Lilly, American Cyanamid, and Upjohn|date=September 2012}}
[[File:Somatotropine.GIF|thumb|right|250px|Image of peptide somatotropine.]]

In 1937, the administration of BST was shown to increase the milk yield in [[lactation|lactating]] cows by preventing mammary cell death in dairy cattle.<ref name=collier/>

Until the 1980s, use of the compound was very limited in agriculture as the sole source of the hormone was from bovine carcasses. During this time, the knowledge of the structure and function of the hormone increased.<ref name = Crooker>{{cite web | title = Dairy Research and Bovine Somatotropin | url = http://www.extension.umn.edu/distribution/livestocksystems/DI6337.html | publisher = [[University of Minnesota]] | last = Crooker | first = BA | year = 1993 |access-date=16 January 2008 | archive-url = https://web.archive.org/web/20070618015651/http://www.extension.umn.edu/distribution/livestocksystems/DI6337.html| archive-date = 18 June 2007|display-authors=etal}}</ref>

With the advent of [[biotechnology]], one of the pioneering biotech companies, [[Genentech]], in 1981 succeeded in cloning and patenting the gene for BST.<ref>{{Cite web|url=https://patents.google.com/patent/US4880910/en|title=Terminal methionyl bovine growth hormone and its use|website=Patents.google.com|access-date=17 March 2022}}</ref> [[Monsanto]] had been working along the same lines and struck a deal with Genentech in 1979 to license Genentech's patents and collaborate on development of a [[Recombinant DNA|recombinant]] version of BST – a process on which Monsanto would invest $300 million.<ref name=Schneider /> The two companies used [[genetic engineering]] to clone the BST gene into ''[[Escherichia coli|E. coli]]''. The bacteria are grown in [[bioreactors]], then broken up and separated from the rBST, which is purified to produce the injectable hormone. They published their first field trial results in 1981.<ref name=Bauman1999>{{cite journal | last1 = Bauman | first1 = D.E. | year = 1999 | title = Bovine somatotropin and lactation: from basic science to commercial application | url = http://www.ansci.cornell.edu/bauman/envir_impact/BaumanDomAnEndo.pdf | journal = Domestic Animal Endocrinology | volume = 17 | issue =  2–3| pages = 101–116 | pmid = 10527114 | doi = 10.1016/s0739-7240(99)00028-4 | url-status = dead | archive-url = https://web.archive.org/web/20120616043549/http://www.ansci.cornell.edu/bauman/envir_impact/BaumanDomAnEndo.pdf | archive-date = 16 June 2012}}</ref><ref>{{cite journal | last1 = Peel | first1 = CJ |display-authors=et al | date = Sep 1981 | title = Effect of exogenous growth hormone on lactational performance in high yielding dairy cows | journal = J Nutr | volume = 111 | issue = 9| pages = 1662–71 | pmid = 7277044 | doi = 10.1093/jn/111.9.1662 }}</ref><ref>{{Cite journal|last=Bauman|first=Dale E.|date=1 December 1992|title=Bovine Somatotropin: Review of an Emerging Animal Technology1|journal=Journal of Dairy Science|volume=75|issue=12|pages=3432–3451|doi=10.3168/jds.S0022-0302(92)78119-3|pmid=1474210|doi-access=free}}</ref>

Lilly, American Cyanamid, Upjohn, and Monsanto all submitted applications to market rBST to the FDA, and the FDA completed its review of the human safety component of these applications in 1986 and found food from rBST-treated cows to be safe; however, strong public concern led to calls for more studies, investigations, and public discussions, which included an unprecedented conference on the safety of rBST in 1990 organized by the [[National Institutes of Health]] <!-- (NIH) --> at the request of Senator [[Patrick Leahy]].<ref name=Audit>{{cite web|url=http://oig.hhs.gov/oas/reports/phs/c9000046.pdf|title=Auditor's Report|website=HHS.gov|access-date=10 May 2017}}</ref> FDA approved Monsanto's application in 1993.<ref>{{cite web|url=https://www.fda.gov/AnimalVeterinary/SafetyHealth/ProductSafetyInformation/ucm055435.htm |title=FDA page on BST |date=13 April 2022 |publisher=FDA.gov }}</ref> Monsanto launched rBST, brand-named "Posilac", in 1994.<ref name = MG>{{cite web | url = http://www.monsantodairy.com/about/general_info/index.html | title = General information – Posilac |access-date=16 January 2008 | year = 2007 | publisher = Monsanto | archive-url = https://web.archive.org/web/20080101123956/http://www.monsantodairy.com/about/general_info/index.html| archive-date = 1 January 2008}}</ref>

==Mechanism of action==
An average [[Dairy cattle|dairy cow]] begins her lactation with a moderate daily level{{Clarify|reason=vague|date=May 2017}} of milk production. This daily output increases until, at about 70 days into the lactation, production peaks. From that time until the cow is dry, production slowly decreases. This increase and decrease in production is partially caused by the count of milk-producing cells in the [[udder]]. Cell counts begin at a moderate number,{{Clarify|reason=vague|date=May 2017}} increase during the first part of the lactation, then decrease as the lactation proceeds. Once lost, these cells generally do not regrow until the next lactation.{{citation needed|date=October 2021}}

Administration of rBST or BST prior to peak production, in cows that are well-fed, slows the rate at which the number of mammary cells decreases, and increases the amount of nutrients directed away from fat and toward the mammary cells, leading to an extension of peak milk production. The effects are mediated by the [[insulin-like growth factor]] (IGF) system, which is [[upregulated]] in response to BST or rBST administration in well-fed cows.<ref name=Bauman1999/><ref>{{cite web | url = http://www.monsantodairy.com/faqs/fda_rbst.html | title= bST Fact Sheet | last = Barbano | first = D | publisher = Monsanto |access-date=16 January 2008 | year = 2007| archive-url = https://web.archive.org/web/20071224141534/http://www.monsantodairy.com/faqs/fda_rbst.html| archive-date = 24 December 2007}}</ref>

==Use on farms==
From 2000 to 2005, the [[United States Department of Agriculture|US Department of Agriculture]] [[National Agricultural Statistics Service]] <!-- (NASS) --> survey of dairy producers found that about 17% of producers used rBST.<ref>Gillespie J et al (2010) [http://www.agbioforum.org/v13n3/v13n3a04-gillespie.pdf Adoption of Recombinant Bovine Somatotropin and Farm Profitability: Does Farm Size Matter?] AgBioForum, 13(3): 251-262.</ref> The 2010 USDA National Agricultural Statistics Service survey of Wisconsin farms found that about 18% of dairy farms used rBST.<ref>Staff, USDA National Agricultural Statistics Service 2010. [http://www.nass.usda.gov/Statistics_by_State/Wisconsin/Publications/Dairy/Dairy_OP_Release_10.pdf 2010 Dairy Producer Survey] {{webarchive|url=https://web.archive.org/web/20120302125728/http://www.nass.usda.gov/Statistics_by_State/Wisconsin/Publications/Dairy/Dairy_OP_Release_10.pdf |date=2 March 2012 }}</ref>

=== Role in synchronized fertilization on dairy farms ===
By using cows that produce offspring within a one to two-week period, [[Estrous synchronization|synchronized breeding]] allows dairy farmers to [[artificially inseminate]] cows for maximum pregnancy rates with minimal effort.<ref>{{cite web|last1=DeJarnette|first1=Mel|title=OVSYNCH, CO-SYNCH, PRESYNCH and KITCHENSYNCH: How did breeding cows get so complicated?|url=http://www.selectsires.com/programs/docs/ovsynch_cosynch_presynch.pdf?version=20161206|website=Select Sires|publisher=Select Sires Inc.}}</ref> BST is a [[placental lactogen]] (PL) hormone and falls under the class of growth hormone, or somatotropin. It is relevant to the practice of artificially expediting placental development in farm mammals, specifically [[dairy cattle]].{{citation needed|date=October 2021}}

The mechanism through which the hormones of this somatotropin exert their effects can be observed at the cellular and molecular level in placental tissue. For mammals exposed to the hormone, bovine somatotropin associates with [[N-linked glycosylation|N-glycosylated]] proteins that are heavily involved in placental gestation. Knowledge of this and how BST works in conjunction with growth hormones allows for agricultural researchers to experiment on the effects of synchronization in farm animals.<ref>{{Cite web|url=http://extension.uga.edu/publications/detail.cfm?number=B1227|title=Dairy Herd Synchronization Programs {{!}} Publications {{!}} UGA Extension|website=extension.uga.edu|access-date=2016-12-10}}</ref>

Synchronization involves treating cattle with a dose of BST before artificially inseminating them, according to a fixed interval schedule. Synchronization and BST treatment may be used to increase first-service pregnancy rates while following this timed artificial insemination protocol. This would therefore allow agricultural researchers to observe the effects of hormones in relation to natural [[estrous cycle]]s. Dairy cattle experienced increased rates of pregnancy during synchronization when exposed to BST.{{citation needed|date=October 2021}}

The effects of BST on this treatment are dependent on the step in the estrous cycle, seeing how BST has a stimulatory effect of [[progesterone]] on the [[corpus luteum]].<ref>{{Cite journal|last=Lopes|first=Fernanda|title=Effects of Presynchronization and Bovine Somatotropin on Pregnancy Rates to a Timed Artificial Insemination Protocol in Lactating Dairy Cows|journal=Journal of Dairy Science|doi=10.3168/jds.s0022-0302(01)74600-0|pmid=11467815|volume=84|issue=7|year=2001|pages=1646–1659|doi-access=free}}</ref>

==Controversy==
Though approved by the FDA in 1993, rBST has been immersed in controversy since the early 1980s.<ref name=Dobs /> Part of the controversy concerns potential effects on [[animal health]] and [[human health]].{{citation needed|date=October 2021}}

===Animal health===
One [[meta-analysis]] published in 2003 suggested a negative impact of rBST's effects on bovine health.<ref name="Dohoo2003b">{{cite journal |pmid=14620861 |year=2003 |last1=Dohoo |first1=IR |last2=Descôteaux |first2=L |last3=Leslie |first3=K |last4=Fredeen |first4=A |last5=Shewfelt |first5=W |last6=Preston |first6=A |last7=Dowling |first7=P |title=A meta-analysis review of the effects of recombinant bovine somatotropin. 2. Effects on animal health, reproductive performance, and culling |volume=67 |issue=4 |pages=252–64 |pmc=280709 |journal=Canadian Journal of Veterinary Research}}</ref> Findings suggested an average increase in milk output ranging from 11–16%, an approximate 24% increase in the risk of clinical [[Mastitis in dairy cattle|mastitis]], a 40% reduction in fertility, and 55% increased risk of developing clinical signs of [[lameness (equine)|lameness]]. The same study reported a decrease in body condition score for cows treated with rBST, though an increase in their dry matter intake occurred.{{citation needed|date=October 2021}}

Another meta-analysis (2003) reported on body condition scores (BCS) but could not reach a conclusion due to lack of [[Homogeneity (statistics)|homogeneity]] in [[study design]] and reporting. They found a trend towards decreased BCS in treated cows but state "Depending on the level of body condition in these cows, this effect may have been beneficial or detrimental."<ref name="Dohoo2003">{{cite journal |pmid=14620860 |year=2003 |last1=Dohoo |first1=IR |last2=Leslie |first2=K |last3=Descôteaux |first3=L |last4=Fredeen |first4=A |last5=Dowling |first5=P |last6=Preston |first6=A |last7=Shewfelt |first7=W |title=A meta-analysis review of the effects of recombinant bovine somatotropin. 1. Methodology and effects on production |volume=67 |issue=4 |pages=241–51 |pmc=280708 |journal=Canadian Journal of Veterinary Research}}</ref> This analysis did not report on clinical mastitis.{{citation needed|date=October 2021}}

A more recent meta-analysis (2014) published by the ''Journal of the [[American Veterinary Medical Association]]'' showed no significant increase in risk of clinical [[Mastitis in dairy cattle|mastitis]] nor other adverse effects on cow health and well-being. This review included 26 peer-reviewed studies that involved the use of the rBST-Zn formulation available to US producers in accordance with the label instructions for treatment initiation (57 to 70 days after birth), dose (500&nbsp;mg, every 14 days), and route (subcutaneous).<ref>{{Cite journal|last1=St-Pierre |first1=Normand R.|last2=Milliken|first2=George A.|last3=Bauman|first3=Dale E.|last4=Collier |first4=Robert J.|last5=Hogan|first5=Joseph S.|last6=Shearer|first6=Jan K.|last7=Smith|first7=K. Larry|last8=Thatcher|first8=William W.|date=22 August 2014|title=Meta-analysis of the effects of sometribove zinc suspension on the production and health of lactating dairy cows|journal=Journal of the American Veterinary Medical Association|volume=245|issue=5|pages=550–564 |doi=10.2460/javma.245.5.550 |issn=0003-1488 |pmid=25148097|s2cid=19446238 }}</ref>

Mastitis has cost American dairy industries an estimated $1.5 to 2 billion per year in treating dairy cows.<ref>{{Cite journal|title = The National Mastitis Council: A Global Organization for Mastitis Control and Milk Quality, 50 Years and Beyond|journal = Journal of Mammary Gland Biology and Neoplasia|date = 19 December 2014|issn = 1083-3021|pages = 241–251|volume = 19|issue = 3–4|doi = 10.1007/s10911-014-9328-6|pmid = 25524293|language = en|first1 = John R.|last1 = Middleton|first2 = Anne|last2 = Saeman|first3 = Larry K.|last3 = Fox|first4 = Jason|last4 = Lombard|first5 = Joe S.|last5 = Hogan|first6 = K. Larry|last6 = Smith|s2cid = 32654206}}</ref>

In 1994, an EU scientific commission was asked to report on the incidence of mastitis and other disorders in dairy cows and on other aspects of their welfare.<ref name="ec.europa.eu"/> The commission's statement, subsequently adopted by the EU, stated that the use of rBST substantially increased health problems with cows, including foot problems, mastitis, and injection site reactions, impinged on the welfare of the animals, and caused reproductive disorders. The report concluded, on the basis of the health and welfare of the animals, rBST should not be used. [[Health Canada]] prohibited the sale of rBST in 1999; the external committees found that there was health risk to humans, and  the drug present a threat to animal health, and, for this reason, cannot be sold in Canada.<ref name=autogenerated1>{{cite web | url = http://www.hc-sc.gc.ca/ahc-asc/media/nr-cp/1999/1999_03_e.html | publisher = [[Health Canada]] | title = Health Canada rejects bovine growth hormone in Canada | date = 14 January 1999 |access-date=16 January 2008 | archive-url = https://web.archive.org/web/20080110050349/http://www.hc-sc.gc.ca/ahc-asc/media/nr-cp/1999/1999_03_e.html| archive-date = 10 January 2008}}</ref>

Monsanto-sponsored trials reviewed by the FDA asked whether the use of rBST makes cows more susceptible to mastitis.<ref name="JECFA 1997">{{cite web | url = http://consumersunion.org/news/potential-public-health-impacts-of-the-use-of-recombinant-bovine-somatotropin-in-dairy-production-part-1/ |title = Potential Public Health Impacts of the Use of Recombinant Bovine Somatotropin in Dairy Production | date = September 1997 |last1=Hansen |first1=Michael |last2=Halloran |first2=Jean M. |last3=Groth |first3=Edward III |last4=Lefferts |first4=Lisa Y.}}</ref> According to the FDA, which used data from eight Monsanto-sponsored trials in its decision in 1993 to approve Monsanto's rBST product, the answer is yes. The data from these eight trials, which involved 487 cows, showed that during the period of rBST treatment, mastitis incidence increased by 76% in [[primiparous]] cows and by 50% for multiparous cows. Overall, the increase was 53%.<ref name="JECFA 1997"/>

Conversely, however, a study from the University of Georgia on the monitoring post-approval of rBST, showed that there was no statistically significant (P > 0.05) derivation in cases of clinical mastitis in dairy cows treated with rBST.<ref>{{Cite web |url=http://www.ads.uga.edu/documents/relationshipbetweentheuseofrecombinantbovinesomatotropinposilacindairycowsandtheincidenceofc.pdf |archive-url=https://web.archive.org/web/20151010092939/http://www.ads.uga.edu/documents/relationshipbetweentheuseofrecombinantbovinesomatotropinposilacindairycowsandtheincidenceofc.pdf |url-status=dead |archive-date=10 October 2015|title=Relationship Between the Use of Recombinant Bovine Somatotropin (Posilac®) in Dairy Cows and the Incidence of Clinical Mastitis |last=McClary |first=David |date=21 December 2010 |publisher=University of Georgia Agriculture |access-date=18 December 2016}}</ref>

====Macronutrient composition====
The overall composition of the milk including the [[fat]], [[protein]], and [[lactose]] content is not altered substantially by the use of rBST in dairy cows. The milk may have a slight change in fat content within the first few weeks of rBST treatment as the cow is allowed to adjust her metabolism and feed intake. The changes in the fat content have been shown to be temporary. The composition of the milk has been examined in more than 200 different experiments. Natural variation within milk is normal with or without rBST treatment in cows due to genetics, location, feed, age, and other environmental factors. Protein in milk content has also been studied and was shown to have no apparent change in rBST treated cows. The vitamins and minerals that are normally in milk were also unaltered in milk from rBST treated cows. Freezing point, pH, thermal properties, and other manufacturing characteristics of milk were shown to be the same regardless of whether it came from rBST treated cows or not.<ref name="Bauman2014">{{cite journal|last1=Collier|first1=R. J.|last2=Bauman|first2=D. E.|title=Update on human health concerns of recombinant bovine somatotropin use in dairy cows|journal=Journal of Animal Science|date=1 April 2014|volume=92|issue=4|pages=1800–1807|doi=10.2527/jas.2013-7383|pmid=24663163|issn=1525-3163}}</ref>

====Hormones====
BST is destroyed in the [[Digestive system of cattle|digestive system]] and even if directly injected, has not been found to have any direct effect on humans.<ref name=Bauman2014/> Researchers have found that "[[Insulin-like growth factor 1|IGF-1]] in milk is not [[Denaturation (biochemistry)|denatured]] by [[pasteurization]] and the extent to which intact, active IGF-1 is absorbed through the human digestive tract remains still however uncertain" implicating that an extensive study on the nature of IGF-1 in relation to rBST milk is required.<ref>{{Cite journal|title = Analytical strategies to detect use of recombinant bovine somatotropin in food-producing animals|journal = TrAC Trends in Analytical Chemistry|date = 1 January 2014|pages = 1–10|volume = 53|doi = 10.1016/j.trac.2013.08.006|first1 = G.|last1 = Dervilly-Pinel|first2 = S.|last2 = Prévost|first3 = F.|last3 = Monteau|first4 = B.|last4 = Le Bizec}}</ref>

FDA rBST labeling guidelines state, "FDA is concerned that the term 'rBST free' may imply a compositional difference between milk from treated and untreated cows rather than a difference in the way the milk is produced. Without proper context, such statements could be misleading. Such unqualified statements may imply that milk from untreated cows is safer or of higher quality than milk from treated cows. Such an implication would be false and misleading".<ref name="grist">{{cite web |url=http://www.grist.org/article/food-2010-10-06-court-rules-on-rbgh-free-milk |title=Court Rules rBGH-Free Milk *Is* Better than the Kind Produced with Artificial Hormones. Now What? |access-date=6 October 2010 |publisher=Grist }}</ref> The FDA has determined that no significant difference has been shown between milk derived from rBST treated and non-rBST treated cows.<ref>Kirkland Signature Organic Milk Carton, Costco</ref>

The FDA,<ref name="fda.gov"/> World Health Organization,<ref name=WHO/> and National Institutes of Health<ref name="NIH RBST"/> have independently stated that dairy products and meat from rBST-treated cows are safe for human consumption. The [[American Cancer Society]] issued a report declaring, "The evidence for potential harm to humans [from rBGH milk] is inconclusive. It is not clear that drinking milk produced using rBGH significantly increases IGF-1 levels in humans or adds to the risk of developing cancer. More research is needed to help better address these concerns."<ref name = "ACS">Staff, American Cancer Society. Last Medical Review: 18 February 2011; Last Revised: 18 February 2011. [http://www.cancer.org/cancer/cancercauses/othercarcinogens/athome/recombinant-bovine-growth-hormone Recombinant Bovine Growth Hormone] {{Webarchive|url=https://web.archive.org/web/20150323041325/http://www.cancer.org/cancer/cancercauses/othercarcinogens/athome/recombinant-bovine-growth-hormone |date=23 March 2015 }}</ref>

===Human health===
The effect of rBGH on human health is an ongoing debate, in part due to the lack of conclusive evidence. A few of the most debated issues include:

[[Insulin-like growth factor 1]] (IGF-1) is a hormone found in humans that is responsible for growth promotion, [[protein synthesis]], and [[insulin]] actions over the lifecycle. The hormone has been shown to influence the growth of tumors in some studies and may be linked to the development of prostate,<ref>{{cite journal | last1 = Allen | first1 = NE | last2 = Key | first2 = TJ | last3 = Appleby | first3 = PN |display-authors=et al | year = 2007 | title = Serum insulin-like growth factor (IGF)-I and IGF-binding protein-3 concentrations and prostate cancer risk: Results from the European Prospective Investigation into Cancer and Nutrition | journal = Cancer Epidemiol Biomarkers Prev | volume = 16 | issue = 6| pages = 1121–1127 |pmid=17548673|doi=10.1158/1055-9965.EPI-06-1062| doi-access = free }}{{open access}}</ref> colorectal, breast,<ref>{{cite journal | last1 = Hankinson | first1 = SE | last2 = Schernhammer | first2 = ES | year = 2003 | title = Insulin-like growth factor and breast cancer risk: Evidence from observational studies | journal = Breast Dis. | volume = 17 | pages = 27–40 |pmid=15687675| doi=10.3233/bd-2003-17104}}</ref><ref>{{cite journal | last1 = Rinaldi | first1 = S | last2 = Peeters | first2 = PH | last3 = Berrino | first3 = F  |display-authors=et al | year = 2006 | title = IGF-I, IGFBP-3 and breast cancer risk in women: The European Prospective Investigation into Cancer and Nutrition (EPIC) | journal = Endocr Relat Cancer | volume = 13 | issue = 2| pages = 593–615 | doi=10.1677/erc.1.01150| pmid = 16728585 | doi-access = free }}</ref> and other cancers.<ref>{{cite journal | last1 = Giovannucci | first1 = E | year = 2003 | title = Nutrition, insulin, insulin-like growth factors and cancer | journal = Hormone and Metabolic Research | volume = 35 | issue = 11/12| pages = 694–704 | doi=10.1055/s-2004-814147| pmid = 14710348 | s2cid = 8695195 }}</ref><ref>{{cite journal | last1 = Furstenberger | first1 = G | last2 = Senn | first2 = HJ | year = 2002 | title = Insulin-like growth factors and cancer | journal = Lancet Oncol | volume = 3 | issue = 5| pages = 298–302 | doi=10.1016/s1470-2045(02)00731-3| pmid = 12067807 }}</ref><ref>{{cite journal | last1 = Giovannucci | first1 = E | last2 = Pollak | first2 = M | last3 = Liu | first3 = Y |display-authors=et al | year = 2003 | title = Nutritional predictors of insulin-like growth factor I and their relationships to cancer in men | journal = Cancer Epidemiol Biomarkers Prev | volume = 12 | issue = 2 | pages = 84–89 | pmid = 12582016 }}</ref>

IGF-1 is also found in milk. Previous research has proposed an increase of IGF-1 in rBST-treated cows, but this claim is currently not substantiated. In addition, no current evidence shows that orally consumed IGF-1 is absorbed in humans and the dietary amount is negligible when compared to what the body produces on its own. "IGF-1 in milk is not denatured (inactivated) by pasteurization. The extent to which intact, active IGF-1 is absorbed through the human digestive tract remains uncertain."{{citation needed|date=October 2021}}

The American Cancer Society has reviewed the evidence concerning IGF-1 in milk from rBST-treated cows, and found that:  "While there may be a link between IGF-1 blood levels and cancer, the exact nature of this link remains unclear.  Some studies have shown that adults who drink milk have about 10% higher levels of IGF-1 in their blood than those who drink little or no milk. But this same finding has also been reported in people who drink [[soy milk]]. This suggests that the increase in IGF-1 may not be specific to cow's milk, and may be caused by protein, minerals, or some other factors in milk unrelated to rBGH. There have been no direct comparisons of IGF-1 levels in people who drink ordinary cow's milk vs. milk stimulated by rBST. At this time, it is not clear that drinking milk, produced with or without rBST treatment, increases blood IGF-1 levels into a range that might be of concern regarding cancer risk or other health effects. IGF-1 concentrations are slightly higher (to variable degrees, depending on the study) in milk from cows treated with rBST than in untreated milk. This variability is presumed to be much less than the normal range of variation of IGF-1 in cow's milk due to natural factors, but more research is needed."<ref name="ACS"/>

As of 2014, evidence does not link rBST-treated milk with adverse health outcomes for children.<ref name="Bauman2014" /> Several studies have looked at the relationship between [[Diabetes mellitus type 1|type 1 diabetes mellitus]] and infant feeding. Environmental triggers that may elicit an autoimmune reaction is the mechanism in which is being studied. Some studies have shown early exposure to bovine milk may predispose an infant to type 1 diabetes, whereas other studies show no causality.<ref>{{cite web|title=Health Concerns about Dairy Products|url=http://www.pcrm.org/health/diets/vegdiets/health-concerns-about-dairy-products|website=The Physicians Committee|language=en|date=13 October 2010}}</ref>

The [[American Society of Animal Science]] published an article in 2014 after reviewing health issues arising from the rBST debate. The article indicated "there are no new human health issues related to the use of rBST by the dairy industry. Use of rBST has no effect on the micro- and macrocomposition of milk. Also, no evidence exists that rBST use has increased human exposure to antibiotic residues in milk. Concerns that IGF-1 present in milk could have biological effects on humans have been allayed by studies showing that oral consumption of IGF-1 by humans has little or no biological activity. Additionally, concentrations of IGF-1 in digestive tract fluids of humans far exceed any IGF-1 consumed when drinking milk. Furthermore, chronic supplementation of cows with rBST does not increase concentrations of milk IGF-1 outside the range typically observed for effects of farm, parity, or stage of lactation. Use of rBST has not affected expression of retroviruses in cattle or posed an increased risk to human health from [[retrovirus]]es in cattle. Furthermore, risk for development of type 1 or [[Diabetes mellitus type 2|type 2 diabetes mellitus]] has not increased in children or adults consuming milk and dairy products from rBST-supplemented cows. Overall, milk and dairy products provide essential nutrients and related benefits in health maintenance and the prevention of chronic diseases."<ref>{{cite journal | last1 = Collier | first1 = R. J. | last2 = Bauman | first2 = D. E. | year = 2014 | title = Update on human health concerns of recombinant bovine somatotropin use in dairy cows | journal = Journal of Animal Science | volume = 92 | issue = 4| pages = 1800–1807 | doi =  10.2527/jas.2013-7383 | pmid=24663163}}</ref>

Keeping in mind that bovine somatotropin is a protein growth hormone, it can increase average milk yield anywhere from 10 to 15%, which in turn would lead to cows consuming substantially more nutrients in order to keep up with the increased milk production. Most of a cow's energy consumption goes directly towards milk production. In certain areas of the world, like Ethiopia where this was studied extensively, as the cows needed to intake more nutrition to balance out their milk production, there was also an increased level of [[chemical fertilizers]] and [[Heavy metals|heavy metal]] traces found in the milk due to increased exposure to agricultural chemicals. These chemicals can then easily be passed on to humans and lead to a contaminated milk supply. BST increases the longevity or the activity of the mammary cell leading to higher milk production and some other non-desirable side effects.<ref>{{Cite journal|last=Centner|first=Terence J.|date=1 September 2016|title=Efforts to slacken antibiotic resistance: Labeling meat products from animals raised without antibiotics in the United States|journal=Science of the Total Environment|volume=563–564|pages=1088–1094|doi=10.1016/j.scitotenv.2016.05.082|pmid=27236477|bibcode=2016ScTEn.563.1088C|doi-access=free}}</ref>

Despite public controversy of the use of growth hormones in food-producing animals, the number of violations has decreased substantially in the past two decades.{{When|date=May 2017}} For comparison, the level of antibiotic-residue detected in bulk milk tank trucks in 2012 was one fifth the level that it was in 1996. As reported by the USDA, the US pattern for milk BTSCC declined steadily from 316,000 cells per mL of milk in 2001 to 224,000 cells/mL in 2010 and 206,000 cells/mL in 2011 (USDA, 2013). Mammary health in the animals themselves has improved over this time period as well as the overall health of the dairy herd in general. This is mostly attributed to better application methods of rBST and a better understanding of how the hormone affects the animals.<ref>{{cite conference |title=An Update on rBST - Human Safety And Animal Efficiency And Welfare |last1=Bauman |first1=D.E.|last2=Collier |first2=R.J.|date=2014|conference= Cornell Nutrition Conference for Feed Manufacturers|hdl = 1813/37969}}</ref>

===Environmental impact===
On an industry level, supplementing one million cows with rBST would result in the same amount of milk produced while needing 157,000 fewer cows.<ref>{{cite journal|last1=Capper|first1=J. L.|last2=Castaneda-Gutierrez|first2=E.|last3=Cady|first3=R. A.|last4=Bauman|first4=D. E.|title=The environmental impact of recombinant bovine somatotropin (rbST) use in dairy production|journal=Proceedings of the National Academy of Sciences|date=30 June 2008|volume=105|issue=28|pages=9668–9673|doi=10.1073/pnas.0802446105|pmid=18591660|pmc=2442129|bibcode=2008PNAS..105.9668C|doi-access=free}}</ref> Farmers are, therefore, able to improve milk production with a smaller dairy population.

Some studies show that rBST-treated cows reduce the [[greenhouse gas footprint]] in comparison with conventional and organic dairy operations. Cady's study showed that excretion of [[nitrogen]] and [[phosphorus]], two major environmental pollutants arising from animal agriculture, was reduced by 9.1 and 11.8%, respectively.<ref name=Capper2008>{{cite journal | last1 = Capper | first1 = JL |display-authors=et al | date = Jul 2008 | title = The environmental impact of recombinant bovine somatotropin (rbST) use in dairy production | journal = Proc Natl Acad Sci U S A | volume = 105 | issue = 28| pages = 9668–73 | doi = 10.1073/pnas.0802446105 | pmid = 18591660 | pmc=2442129| bibcode = 2008PNAS..105.9668C | doi-access = free }}</ref> [[Carbon dioxide]] is recognized to be the most important [[anthropogenic greenhouse gas]],<ref>Intergovernmental Panel on Climate Change.  [http://www.ipcc.ch/publications_and_data/publications_ipcc_fourth_assessment_report_wg1_report_the_physical_science_basis.htm IPCC Fourth Assessment Report (AR4) Climate Change 2007: The Physical Science Basis]</ref> and livestock metabolism and fossil fuel consumption are the main sources of emissions from animal agriculture.{{Citation needed|date=December 2023}}
* Livestock metabolism-use of rBST in lactating cows decreases the quantity of energy and protein needed in comparison to conventional dairy operations along with reducing the total foodstuff used.{{Citation needed|date=December 2023}}
* Fossil fuel consumption-targets atmospheric pollution and resource sustainability environmental concerns. With cows treated with rBST, producing a higher milk yield reduces the feed requirement which in turn decreases with electricity for milk production and the energy required from fossil fuels for cropping. In addition, the [[global warming potential]] is reduced equivalent to removing 400,000 family cars from the road.{{Citation needed|date=December 2023}}
When conventional, conventional with rBST, and organic dairy operations are compared, 8% fewer cows are needed in an rBST-supplemented population, whereas organic production systems require a 25% increase to meet production targets.<ref name=Capper2008/> This is due to a lower milk yield per cow due to the pasture-based system which is attributed with a greater maintenance energy expenditure associated with grazing behavior.<ref>Subcommittee on Dairy Cattle Nutrition; Committee on Animal Nutrition; Board on Agriculture and Natural Resources (BANR); Division on Earth and Life Studies (DELS); National Research Council  [http://www.nap.edu/openbook.php?isbn=0309069971 Nutrient Requirements of Dairy Cattle: Seventh Revised Edition. National Academies Press, 2001]</ref>{{rp|20–21}}

===Lawsuit against WTVT===
In 1997, the news division of [[WTVT]] (Channel 13), a [[Fox Television Stations Group|Fox-owned station]] in [[Tampa, Florida]], planned to air an investigative report by [[Steve Wilson (reporter)|Steve Wilson]] and [[Jane Akre]] on the health risks associated with Monsanto's bovine growth hormone product, Posilac.<ref name="sptimes.com">{{cite web|url=http://www.sptimes.com/News/081900/TampaBay/Reporter_wins_suit_ov.shtml |title=Reporter wins suit over firing |publisher=SPTimes.com |date=19 August 2000 |access-date=28 October 2011}}</ref> Just before the story was to air, Fox received a letter from Monsanto saying the reporters were biased and that the story would damage the company.<ref name="sptimes.com" /> Akre stated that Wilson and she went through 83 rewrites over eight months.<ref>''Deconstructing Supper''. Dir. Marianne Kaplan. Prod. Leonard Terhoch & Marianne Kaplan. 2002. VHS. Retrieved 24 November 2011. (23-minute mark.)</ref> Negotiations broke down and both reporters were eventually fired. Wilson and Akre alleged the firing was for retaliation, while WTVT contended they were fired for [[insubordination]].<ref name="sptimes.com" /> The reporters then sued Fox/WTVT in Florida state court under the state's [[whistleblower]] statute. In 2000, a Florida jury found that while no evidence showed Fox/WTVT had bowed to any pressure from Monsanto to alter the story, Akre, but not Wilson, was a whistleblower and was unjustly fired.<ref name="sptimes.com" /> She was awarded a $425,000 settlement. At the time of the decision, "the station claimed it did not bend to Monsanto's letter and wanted to air a hard-hitting story with a number of statements critical of Monsanto."<ref name="sptimes.com" /> Fox appealed the decision stating that under Florida law, a whistleblower can only act if "a law, rule, or regulation" has been broken and argued that the FCC's policy against distortions or misrepresentations presented as news did not fit that definition.<ref name="decision">{{cite web|url=https://caselaw.findlaw.com/fl-district-court-of-appeal/1310807.html |title=NEW WORLD COMMUNICATIONS OF TAMPA INC WTVT TV v. AKRE, No. 2D01-529., February 14, 2003&nbsp;– FL District Court of Appeal &#124; FindLaw |publisher=Caselaw.findlaw.com }}</ref> On 14 February 2003, the appeals court overturned the verdict, finding that Akre was not a whistleblower because of the Florida "legislature's requirement that agency statements that fit the definition of a "rule" (must) be formally adopted (rules). Recognizing an uncodified agency policy developed through the adjudicative process as the equivalent of a formally adopted rule is not consistent with this policy, and it would expand the scope of conduct that could subject an employer to liability beyond what Florida's Legislature could have contemplated when it enacted the whistle-blower's statute."<ref name="decision" />

==Regulation==
Use of the recombinant supplement has been controversial.<ref name=collier>{{cite journal
|url=http://www.agbioforum.org/v3n23/v3n23a14-collier.htm
|title=Regulation of rbST in the US
|author=Robert Collier
|journal=AgBioForum
|volume=3
|year=2000
|pages=156–163
}}</ref><ref name=sencoagfor>{{Cite web|url=https://sencanada.ca/en/committees/|title=Committees|first=Senate of|last=Canada|website=Sencanada.ca|access-date=17 March 2022}}</ref> The assessment of the FDA is that there is no significant difference between milk from treated and untreated cows.<ref name = "nytimes milk label" /><ref>FDA Analysis of DGXXIV Report on Public Health Aspects of BST. [https://www.fda.gov/AnimalVeterinary/NewsEvents/CVMUpdates/ucm130353.htm Link.] {{webarchive |url=https://web.archive.org/web/20120210082627/https://www.fda.gov/AnimalVeterinary/NewsEvents/CVMUpdates/ucm130353.htm |date=10 February 2012 }}</ref> Twenty-one other countries have also approved marketing of rBST: Brazil, Chile, Colombia, Costa Rica, Ecuador, Egypt, Guatemala, Honduras, Jamaica, Lebanon, Mexico, Panama, Paraguay, Peru, Salvador, South Africa, South Korea, Uruguay, and Venezuela.  However, regulatory bodies in several countries, such as Canada, Japan, Pakistan, Australia, New Zealand, and Argentina, along with the EU, rejected Monsanto's application to sell rBST<ref name="ec.europa.eu"/><ref name="autogenerated1"/><ref name=IP.99.978>[http://europa.eu/rapid/pressReleasesAction.do?reference=IP/99/798&format=HTML&aged=0&language=EN&guiLanguage=en europa.eu: "Commission proposes ban on BST."], press release IP/99/978.</ref> because rBST increases the risk of health problems in cows, including [[Mastitis in dairy cattle|mastitis]], reduced fertility, and reduced body condition.<ref name="Dohoo2003"/><ref name="Dohoo2003b"/><ref>Horovitz, Bruce. [https://www.usatoday.com/money/industries/food/2009-03-15-dairy-growth-hormone-ban_N.htm Companies cut synthetic hormone from dairy products], ''USA Today'', 16 March 2009. Retrieved 20 May 2009.</ref> In Canada, bulk milk products from the United States that have been produced with rBST are still allowed to be sold and used in food manufacture (cheese, yogurt, etc.) due to loopholes in the ingredient labelling system.<ref name=prb981e>[http://publications.gc.ca/collections/Collection-R/LoPBdP/BP/prb981-e.htm Parliamentary Research Branch: "RECOMBINANT BOVINE SOMATOTROPIN (rbST)"] PRB 98-1E, prepared by:
Frédéric Forge
Science and Technology Division
October 1998
Revised 11 August 1999
</ref>

In 1990, the EU placed a [[Moratorium (law)|moratorium]] on its sale by all member nations. It was turned into a permanent ban starting from 1 January 2000; the decision was based solely on veterinary concerns, laws, and treaties.<ref name=eucelex>{{cite web|url=http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:31999D0879:EN:HTML |title=European Council Decision of December 17, 1999 |publisher=Eur-lex.europa.eu }}</ref> An in-depth report published in 1999 analysed in detail the various human health risks associated with rBST.<ref>{{cite web| title=Report on Public Health Aspects of the Use of Bovine Somatotrophin|url=http://ec.europa.eu/food/fs/sc/scv/out19_en.html|year=1999}}</ref>

Canada's health board, [[Health Canada]], refused to approve rBST for use on Canadian dairies, citing concerns over animal health.<ref name=autogenerated1 /> The study found the occurrence of an [[antibody]] reaction, possible hypersensitivity, in a subchronic (90-day) study of rbST oral toxicity in rats that resulted in one test animal's developing an antibody response at low dose (0.1&nbsp;mg/kg/day) after 14 weeks. However, the board stated, with the exception of concerns raised regarding hypersensitivity, "the panel finds no biologically plausible reason for concern about human safety if rBST were to be approved for sale in Canada."<ref>{{cite web|url=http://www.hc-sc.gc.ca/dhp-mps/vet/issues-enjeux/rbst-stbr/rep_rcpsc-rap_crmcc_e.html |title=Executive Summary – Report of the Royal College of Physicians and Surgeons of Canada Expert Panel on Human safety of rBST |publisher=Hc-sc.gc.ca |date=21 August 2009 }}</ref>

The [[Codex Alimentarius]] Commission, a [[United Nations]] body that sets international food standards, has, as of 2017, refused to approve rBST as safe. The Codex Alimentarius does not have authority to ban or approve the hormone, but its decisions are regarded as a standard and approval by the Codex would have allowed exporting countries to challenge countries with a ban on rBST before the [[World Trade Organization]].<ref>{{cite web|url=http://www.foxbghsuit.com/codex063099.htm |title=International Health Group Shuns Bgh |publisher=Foxbghsuit.com |date=3 July 1999 }}</ref>

=== Abuse on dairy farms ===
Recombinant bovine somatotropin is an artificially synthesized form of the bovine growth hormone. It is legal for use as an artificial cattle lactation stimulant in several countries, including the US. However, its use is prohibited in most of Europe for reasons of consumer preference, animal well-being, and skepticism of new technology.<ref>{{cite web|last1=Bauman|first1=Dale E.|title=Facts about Recombinant Bovine Somatotropin (rbST)|url=https://ansci.cals.cornell.edu/sites/ansci.cals.cornell.edu/files/shared/documents/Recombinant%20Bovine%20Somatotropin_v3.pdf|website=Cornell University|date=7 June 2023 |publisher=Department of Animal Science}}</ref> Farmers who opt to use the synthetic hormone do so because they believe it increases milk production without other inputs. However, concerns of both product safety and livestock abuse have prompted discussions for new methods in [[assaying]] the levels of dairy cattle rBST. One proposed method involves quantifying the presence or absence of the rBST-binding antibody in serum. However, this method would require blood samples to be taken regularly and is thus considered by some critics{{Who|date=May 2017}} to be too invasive. The development of other alternative methods continues to undergo development. One such example, tested by W.W. Thatcher at the University of Florida,<ref>{{cite journal|title=Meta-analysis of the effects of sometribove zinc suspension on the production and health of lactating dairy cows|first1=Normand R.|last1=St-Pierre|first2=George A.|last2=Milliken|first3=Dale E.|last3=Bauman|first4=Robert J.|last4=Collier|first5=Joseph S.|last5=Hogan|first6=Jan K.|last6=Shearer|first7=K. Larry|last7=Smith|first8=William W.|last8=Thatcher|date=1 September 2014|journal=J. Am. Vet. Med. Assoc.|volume=245|issue=5|pages=550–564|doi=10.2460/javma.245.5.550|pmid=25148097|s2cid=19446238 }}</ref> involves collecting milk samples from the cows and analyzing them directly for the presence of the rBST antibody. Dairy cattle do respond to the rBST [[antigen]] and have shown positive results in [[Immunosorbent assay|immunosorbent]] trials on milk samples. Tests involving pasteurized milk samples have even shown consistent results, with immunoglobulin rBST still detectable and distinguishable despite other antibodies remaining present. Research on the viability of this new technique, as well as many others,<ref>{{cite web|url=http://cn.agilent.com/cs/library/applications/5989-8481EN.pdf|title=Detection of Recombinant Bovine Somatotropin in Milk by LC-ESI-MS/MS|website=Cn.agilent.com|access-date= 17 March 2022}}</ref> as a means of monitoring the levels of rBST in dairy cattle continues to be an issue of practicality, profitability, and humaneness towards livestock in the dairy industry.<ref>{{Cite journal|doi=10.1016/j.foodcont.2011.12.011|title=Monitoring milk for antibodies against recombinant bovine somatotropin using a microsphere immunoassay-based biomarker approach|journal=Food Control|volume=26|pages=68–72|year=2012|last1=Ludwig|first1=Susann K.J.|last2=Smits|first2=Nathalie G.E.|last3=Bremer|first3=Maria G.E.G.|last4=Nielen|first4=Michel W.F.}}</ref>

===United States===
In 1993, the product was approved for use in the US by the FDA, and its use began in 1994. The product is now sold in all 50 states.{{Citation needed|date=December 2023}}

The FDA stated that food products made from rBST-treated cows are safe for human consumption, and no statistically significant difference exists between milk derived from rBST-treated and untreated cows.<ref name="fda.gov">{{cite web | url = https://www.fda.gov/AnimalVeterinary/SafetyHealth/ProductSafetyInformation/ucm130321.htm | title = Report on the Food and Drug Administration's Review of the Safety of Recombinant Bovine Somatotropin | website = [[Food and Drug Administration]] |access-date=2 May 2009 | year = 1999 }}</ref> The FDA found BST to be biologically inactive when consumed by humans and found no biological distinction between rBST and BST.<ref name="fda.gov"/> In 1990, an independent panel convened by the National Institute of Health supported the FDA opinion that milk and meat from cows supplemented with rBST is safe for human consumption.<ref name="NIH RBST">{{cite book |chapter-url=https://www.ncbi.nlm.nih.gov/books/NBK15180/ |chapter=Bovine Somatotropin |title=NIH State of the Science Statements |year=2002 |publisher=National Institutes of Health}}</ref>

====Labeling====
The FDA does not require special labels for products produced from cows given rBST, but has charged several dairies with "misbranding" their milk as having no hormones, because all milk contains hormones and cannot be produced in such a way that it would not contain any hormones.<ref>{{cite web |first1=Janet |last1=Raloff |date=November 2003 |title=Hormones in Your Milk |url=http://www.sciencenews.org/view/generic/id/4375/title/Food_for_Thought__Hormones_in_Your_Milk |work=[[Science News]] |access-date=6 August 2012}}</ref> Monsanto sued [[Oakhurst Dairy]] of Maine over its use of a label which pledged not to use artificial growth hormones.<ref name="0708-10.htm">{{cite news | url = http://www.commondreams.org/headlines03/0708-10.htm | title = Oakhurst Sued by Monsanto Over Milk Advertising | last = Wickenheiser | first = M | work = [[Portland Press Herald]] | access-date = 29 January 2008 | date = 8 July 2003 | url-status = dead | archive-url = https://web.archive.org/web/20080201163140/http://www.commondreams.org/headlines03/0708-10.htm | archive-date = 1 February 2008}}</ref> The dairy stated that its disagreement was not over the scientific evidence for the safety of rBST (Monsanto's complaint about the label), but, "We're in the business of marketing milk, not Monsanto's drugs." The suit was settled when the dairy agreed to add a qualifying statement to its label: "FDA states: No significant difference in milk from cows treated with artificial growth hormones." The FDA recommends this additional labeling, but does not require it.<ref name="0708-10.htm"/><ref>{{cite web |url=http://www.purefood.org/monsanto/mainegives122903.cfm |title=Maine Dairy Caves in to Pressure from Monsanto on rBGH-Free Labeling |publisher=Purefood.org |date=25 December 2003 |url-status=dead |archive-url=https://web.archive.org/web/20160106231643/http://www.purefood.org/monsanto/mainegives122903.cfm |archive-date=6 January 2016  }}</ref> The settlement itself caused much controversy, with anti-rBST advocates claiming that Oakhurst had capitulated in response to intimidation by a larger corporation and others claiming that Oakhurst's milk labels were in and of themselves using misleading scare tactics that deserved legal and legislative response.{{Citation needed|date=December 2023}}

==== Ohio ====
In 2008, [[Ohio Department of Agriculture|Ohio's Department of Agriculture]] (ODA) banned the use of labeling in dairy products as rBST-free because it was deemed misleading to consumers. However, the International Dairy Foods Association and the [[Organic Trade Association]] claimed ODA's ban was a violation of the [[First Amendment to the United States Constitution|first amendment]] by not allowing consumers to decide whether they deem the milk was safe and filed suit against the bill. "The district court granted summary judgment in favor of Ohio, concluding that using 'rBST' as a label was inherently misleading because it implies a compositional difference between those products that are produced with rBST and those that are not."<ref>{{Cite journal|title = Recent Developments in Health Law|journal = The Journal of Law, Medicine & Ethics|date = 1 March 2011|issn = 1748-720X|pages = 96–101|volume = 39|issue = 1|doi = 10.1111/j.1748-720X.2011.00554.x|pmid = 21314799|language = en|first1 = Cordaro|last1 = Rodriguez|first2 = Elena|last2 = Papoulias| s2cid=219951038 }}</ref>

====Kansas====
In 2009, the [[Kansas Legislature]] passed a bill that would have required dairies that did not use rBST to print disclaimers on their labels that stated, "The Food and Drug Administration has determined there are no significant differences between milk from cows that receive injections of the artificial hormone and milk from those that do not." The bill was vetoed in the last days of the 2009 legislative session by then-Governor [[Kathleen Sebelius]]. The legislature removed the labeling language and passed the bill without the provision.<ref>{{cite web | url = http://www.ethicurean.com/2009/05/04/kansas-milk-labels/ | title = Kansas Senate leaves rBST milk labels on ag committee floor | access-date = 28 October 2011 | date = 23 April 2009 | format = PDF | publisher = [[Consumers Union]] | archive-url = https://web.archive.org/web/20111215210209/http://www.ethicurean.com/2009/05/04/kansas-milk-labels/ | archive-date = 15 December 2011 | url-status = dead }}</ref>

====Pennsylvania====
In 2007, [[Pennsylvania]] adopted a regulation that would have banned the practice of labeling milk as derived from cows not treated with rBST. Pennsylvania's Agriculture Secretary Dennis Wolff made a statement in support of the measure.<ref>{{cite web |url=http://www.earthfarmfriendly.com/News/frustvenmilkmrkt-102606.html |title=Frustrations Vented Over Questionable Milk Marketing Practices – October 26, 2006 |publisher=Earthfarmfriendly.com |date=26 October 2006 |access-date=24 September 2010 |url-status=dead |archive-url=https://web.archive.org/web/20110511210359/http://www.earthfarmfriendly.com/News/frustvenmilkmrkt-102606.html |archive-date=11 May 2011}}</ref> This prohibition was to go into effect 1 January 2008, but after the comment period, the guidelines were adjusted to only ban "rBST-free" claims and instead allow claims that farmers had pledged not to use rBST and accompany such claims with a disclaimer such as, "No significant difference has been shown between milk derived from rBST-treated and non-rBST-treated cows."<ref>{{cite news |url=http://www.post-gazette.com/pg/08018/850269-85.stm | title = State reverses on dairy labeling, allows hormone claims | date = 18 January 2008 |access-date=29 January 2008 | last = Malloy | first = D | work = [[Pittsburgh Post-Gazette]] }}</ref>

==Response from milk producers and retailers==
In response to concerns from consumers and advocacy groups about milk from cows treated with rBST, some dairies, retailers, and restaurants have published policies on use of rBST in production of milk products they sell, while others offer some products or product lines that are labelled "rBST-free" or the like. Other dairies and industry groups have worked to assure the public that milk from rBST-treated cows is safe.{{citation needed|date=October 2021}}

In reaction to these trends, in early 2008, a pro-rBST advocacy group called American Farmers for the Advancement and Conservation of Technology (AFACT),<ref>{{cite web|url=http://itisafact.org/ |title=AFACT: American Farmers for the Advancement and Conservation of Technology |publisher=Itisafact.org }}</ref> made up of dairies and originally affiliated with Monsanto, formed and began lobbying to ban such labels. AFACT stated that "absence" labels can be misleading and imply that milk from cows treated with rBST is inferior.<ref name = "nytimes milk label">[https://www.nytimes.com/2008/03/09/business/09feed.html "Fighting on a Battlefield the Size of a Milk Label"] from ''[[The New York Times]]''</ref> The organization was dissolved in 2011.<ref>{{cite web |url=http://itisafact.org/category/news/ |title=News &#124; AFACT: American Farmers for the Advancement and Conservation of Technology |publisher=Itisafact.org |date=14 April 2011 |url-status=dead |archive-url=https://web.archive.org/web/20130116120835/http://itisafact.org/category/news/ |archive-date=16 January 2013  }}</ref>

The International Dairy Foods Association has compiled a list, last updated in 2009, of state regulations in the U.S. for referencing use of growth hormones on milk labels.{{Citation needed|date=December 2023}}

===Response from health organizations===
* The [[American Cancer Society]] "has no formal position regarding rBGH".<ref>{{Cite web|url=https://www.cancer.org/cancer/cancer-causes/recombinant-bovine-growth-hormone.html|title=Recombinant Bovine Growth Hormone|website=Cancer.org|access-date=17 March 2022}}</ref>
* The [[American Nurses Association]] supports the development of national and state laws, regulations, and policies that specifically reduce the use of rBGH or rBST in milk and dairy production in the United States.<ref>{{cite web|title=American Nurses Association|url=http://www.nursingworld.org/MainMenuCategories/WorkplaceSafety/Healthy-Work-Environment/Environmental-Health/HealthyFoodinHealthCare.pdf|access-date=15 April 2016|archive-url=https://web.archive.org/web/20160611040412/http://www.nursingworld.org/MainMenuCategories/WorkplaceSafety/Healthy-Work-Environment/Environmental-Health/HealthyFoodinHealthCare.pdf|archive-date=11 June 2016|url-status=dead}}</ref>

===Response from political organizations===
* Health Care Without Harm opposes the use of recombinant bovine growth hormone due to its adverse impacts on animals and potential harm to humans.<ref>{{cite web|title=Health Care Without Harm|url=https://noharm.org/sites/default/files/lib/downloads/food/HCWH_Position_on_rBGH.pdf|website=Noharm.org}}</ref>{{Primary source inline|date=October 2020}}
* Oregon Physicians for Social Responsibility recommends buying products from cows not injected with recombinant bovine growth hormone (rBGH or rBST).<ref>{{Cite web|url=http://action.psr.org/documents/dairyguide.htm|title=Oregon Physicians for Social Responsibility- Consumers Dairy Guide|website=Action.psr.org|access-date=17 March 2022}}</ref>{{Primary source inline|date=October 2020}}

=== Production and profitability ===
One study found a profit of $15.88 US per cow on average by using rBST.<ref>{{cite book|last1=Tauer|first1=L.W.|editor1-last=Santaniello|editor1-first=Vittorio|editor2-last=Evenson|editor2-first=Robert E.|editor3-last=Zilberman|editor3-first=David|title=Market development for genetically modified foods|url=https://archive.org/details/marketdevelopmen00sant|url-access=registration|date=2001|publisher=CABI|location=Wallingford, Okon, UK|isbn=978-0851995731|pages=[https://archive.org/details/marketdevelopmen00sant/page/n87 81]–90|chapter=The impact of bovine somatotropin on farm profits}}</ref>

==See also==
{{portal|Agriculture and Agronomy}}
* [[Genetic engineering]]
* [[Genetically modified food]]
* [[Growth hormone treatment]]
* [[Industrial agriculture]]
* [[List of recombinant proteins]]
* [[Recombinant DNA]]
* [[Somatotropin family]]

==References==
{{Reflist}}

{{GH/IGF-1 axis signaling modulators}}

{{DEFAULTSORT:Bovine Somatotropin}}
[[Category:1981 in biotechnology]]
[[Category:Agriculture in the United States]]
[[Category:Agricultural research]]
[[Category:Animal welfare]]
[[Category:Biotechnology products]]
[[Category:Dairy farming technology]]
[[Category:Drugs developed by Eli Lilly and Company]]
[[Category:Genetic engineering and agriculture]]
[[Category:Growth hormones]]
[[Category:Peptide hormones]]
[[Category:Veterinary drugs]]