# Dairy Cow rBST Use: Regulations, Effects, and Alternatives ## Key Takeaways - Recombinant bovine somatotropin (rBST) is approved by the U.S. FDA to increase milk production but is banned in Canada, the EU, Japan, and other markets due to animal welfare concerns and potential health risks to cows, including increased mastitis and reduced fertility. - rBST administration consistently increases milk yield, with meta-analyses quantifying production responses, but can lead to adverse health effects such as a higher incidence of clinical mastitis and decreased conception rates, necessitating rigorous herd health monitoring. - Consumer perception is a significant factor, with negative attitudes prevalent in many markets driving retailer and processor requirements for rBST-free milk, impacting market access for producers using the hormone. - Alternatives to rBST for enhancing milk production include genetic selection for persistent lactation, optimizing nutritional management strategies, and improving overall herd health and comfort, which align with organic dairy farming standards. - Decision-making regarding rBST use requires a structured herd-level assessment of baseline health metrics (e.g., mastitis rates, conception rates), market access verification, economic projections, and risk tolerance, often involving pilot group studies before full herd implementation. - Essential record-keeping for rBST use includes detailed treatment logs, health event tracking, milk production data, and reproductive performance, crucial for management decisions, compliance with buyer requirements, and potential certification programs. --- Recombinant bovine somatotropin (rBST) is a synthetic growth hormone approved by the U.S. Food and Drug Administration (FDA) for use in dairy cows to increase milk production. This article reviews the regulatory status of rBST in different markets, its documented effects on milk yield and cow health, consumer perception trends, and practical alternatives including genetic selection and nutritional management. The information is intended to help dairy farmers evaluate whether rBST aligns with their production goals, market access requirements, and herd health priorities. ## At a Glance: rBST Use in Dairy Operations | Factor | rBST Use | No rBST Use | Alternative Approaches | |--------|----------|-------------|----------------------| | Milk yield effect | Increases production per cow per lactation cycle | Baseline production | Genetic selection for persistent lactation | | Regulatory status | Approved in the United States, banned in Canada, European Union, Japan, and other markets | No regulatory restrictions | No regulatory restrictions | | Consumer perception | Negative in many markets, some processors require rBST-free milk | Preferred by many retailers and consumers | Aligns with organic and natural product claims | | Cow health considerations | Increased risk of clinical mastitis, reduced conception rates, and injection site reactions | No additional hormone-related health risks | Improved through balanced nutrition and breeding | | Record keeping requirements | Must document treatment dates, doses, and cow identification | No rBST-specific records needed | Records of genetic evaluations and feed formulations | ## Regulatory Status of rBST in Major Dairy Markets ### United States FDA Approval and Oversight The FDA approved rBST for commercial use in dairy cattle in 1993 after determining that milk and meat from treated cows are safe for human consumption. The agency continues to monitor the product through its post-market surveillance programs. The United States Department of Agriculture (USDA) provides voluntary certification programs for producers who wish to label milk as rBST-free, but the FDA does not require labeling of milk from treated cows. The Natural Resources Conservation Service (NRCS) offers technical guidance on dairy management practices that may be relevant to operations using or avoiding rBST, though the agency does not directly regulate the hormone. ### Canadian and European Union Bans Health Canada banned rBST for sale and use in dairy cattle in 1999 after concluding that the product posed potential health risks to cows, including increased rates of mastitis and reduced fertility. The European Union implemented a ban on rBST in 2000 under Council Directive 1999/879/EC, citing animal welfare concerns and the precautionary principle. These bans remain in effect and have shaped dairy production systems in those regions. Farmers exporting dairy products to Canada or the EU must ensure their milk supply chains are certified rBST-free. ### Other International Regulatory Approaches Japan, Australia, New Zealand, and several other countries have also prohibited rBST use in dairy cattle. In contrast, countries such as Brazil and Mexico permit rBST use, and research continues on its effects in tropical production systems. A study conducted in a large commercial dairy herd in Brazil examined the lactation performance of Holstein cows treated with two formulations of rBST, contributing to the body of knowledge on its use in warm climates. ## Effects of rBST on Milk Yield and Composition ### Documented Milk Production Increases Research consistently shows that rBST administration increases milk yield in dairy cows. A systematic review and meta-analysis published in Research in [Veterinary Science](/blog/news/veterinary-science) in 2024 examined lactation performance, feed efficiency, and blood metabolites in cows treated with rBST. The analysis aggregated data from multiple studies to quantify production responses. Earlier dose-range studies, including one published in Domestic Animal Endocrinology in 1994, established the relationship between rBST dose and milk output. ### Milk Composition Changes Milk from rBST-treated cows generally maintains normal composition for fat, protein, and lactose percentages, though some studies report minor variations. The FDA has determined that milk from treated cows is compositionally equivalent to milk from untreated cows for human consumption. However, processors and retailers may impose their own standards requiring rBST-free milk, which affects market access for producers who use the hormone. ### Feed Efficiency Considerations The meta-analysis from 2024 also addressed feed efficiency in rBST-treated cows. Increased milk output per unit of feed intake is a reported benefit, but the magnitude of efficiency gains depends on baseline nutrition, cow genetics, and management practices. Farmers considering rBST should evaluate whether their feeding program can support the increased nutrient demands of treated cows without compromising body condition or health. ## Cow Health and Welfare Impacts ### Mastitis Risk and Udder Health One of the most consistently reported adverse effects of rBST use is an increased incidence of clinical mastitis. The mechanism involves the physiological stress of elevated milk production, which can compromise immune function and udder defense mechanisms. Farmers using rBST must implement rigorous mastitis prevention protocols, including proper milking hygiene, regular udder health monitoring, and prompt treatment of clinical cases. Records of mastitis events and [somatic cell](/blog/guides/somatic-cell) counts should be tracked separately for treated and untreated cows to evaluate the impact on individual animals. ### Reproductive Performance rBST treatment has been associated with reduced conception rates and altered reproductive function. A study published in Animal Reproduction Science in 2006 examined the effect of a single rBST treatment at breeding on conception rates and pregnancy retention in dairy and beef cattle. The findings indicated that timing of administration relative to breeding may influence outcomes. Farmers should consult with their veterinarian to determine whether rBST use is compatible with their herd's reproductive management goals and whether adjustments to breeding protocols are needed. ### Injection Site Reactions and Animal Welfare rBST is administered by injection, typically every 14 days. Injection site reactions, including swelling, pain, and tissue damage, can occur. Proper injection technique, needle hygiene, and site rotation are essential to minimize discomfort and prevent secondary infections. The Merck Veterinary Manual provides guidance on injection procedures and site management for cattle. Farmers should train personnel in proper administration and document any adverse reactions. ### Metabolic and Physiological Effects Long-term rBST use can alter metabolic pathways and blood metabolite profiles. A study published in Thai Journal of [Veterinary Medicine](/blog/careers/veterinary-medicine-careers-from-clinical-practice-to-public-health) in 2011 investigated respiratory hypocapnia at different stages of lactation during long-term exogenous bovine somatotropin treatment in crossbred Holstein cattle in the tropics. This research highlights the need for monitoring respiratory and metabolic health in treated cows, particularly in hot climates where heat stress compounds physiological demands. ## Consumer Perception and Market Demands ### Public Attitudes Toward rBST Consumer awareness of rBST varies by region, but negative perceptions are common in many markets. A study published in the Journal of Dairy Science in 2016 examined public and farmer perceptions of dairy cattle welfare in the United States. The research found that consumers often associate rBST use with reduced animal welfare, even though farmers may view the product as a legitimate production tool. These perceptions influence purchasing decisions and retailer policies. ### Retailer and Processor Requirements Many major dairy processors and retailers in the United States and other countries require their milk suppliers to certify that milk is rBST-free. These requirements are driven by consumer demand and marketing strategies. Farmers who sell milk to processors with rBST-free policies must maintain documentation proving that no rBST was used. This may include affidavits, feed records, and veterinary treatment logs. ### [Organic Dairy Farming](/knowledge/animal-farming/dairy-cattle/organic-dairy-farming-standards-practices-and-certification) and rBST Organic dairy certification under the USDA National Organic Program prohibits the use of rBST. Organic dairy farmers must maintain detailed records of all inputs and treatments to verify compliance. The premium prices paid for organic milk often offset the lower production per cow compared to conventional systems using rBST. Farmers considering transitioning to organic production should evaluate the economic trade-offs and market opportunities. ## Alternatives to rBST for Increasing Milk Production ### Genetic Selection for Persistent Lactation Breeding programs that select for higher milk yield, longer lactation persistence, and improved feed efficiency offer a sustainable alternative to rBST. Genomic testing allows farmers to identify heifers and cows with superior genetic potential for milk production without the need for exogenous hormones. The NRCS provides technical assistance for developing breeding plans that align with farm goals and environmental conditions. ### Nutritional Management Strategies Optimizing the ration to support peak milk production can reduce the need for rBST. Key nutritional strategies include balancing energy and protein levels, ensuring adequate fiber for rumen health, and supplementing with minerals and vitamins that support lactation. The Merck Veterinary Manual offers guidance on dairy cattle nutrition and feeding management. Farmers should work with a nutritionist to formulate rations that match the production stage and body condition of each cow group. ### Herd Health and Comfort Improvements Milk production is influenced by cow comfort, stress levels, and overall health. Investments in housing, ventilation, bedding, and heat abatement can improve production without pharmaceutical intervention. Regular hoof trimming, vaccination programs, and parasite control also contribute to higher milk yields. These management practices align with consumer expectations for animal welfare and can be documented for certification programs. ### Use of Bovine Somatotropin from Non-Recombinant Sources Some farmers explore the use of naturally occurring bovine somatotropin, which is produced by the cow's pituitary gland. However, commercial products are derived from [recombinant DNA](/blog/guides/recombinant-dna) technology, and natural sources are not available as a practical alternative. The distinction between recombinant and natural somatotropin is relevant for regulatory and labeling purposes. ## Practical Implementation and Assessment Steps ### Step 1: Evaluate Market Requirements Before deciding to use rBST, determine whether your milk buyer or processor accepts milk from treated cows. Review your supply contract and any certification requirements. If you sell to multiple buyers, consider whether separate handling and storage of rBST-free milk is feasible. ### Step 2: Consult with Your Veterinarian Discuss the potential health impacts of rBST with your herd veterinarian. Review your herd's current mastitis rates, reproductive performance, and metabolic health. Your veterinarian can help you assess whether rBST is appropriate for your herd and develop a monitoring plan. ### Step 3: Develop a Treatment Protocol If you decide to use rBST, establish a written protocol that specifies: - Cow eligibility criteria (e.g., lactation stage, health status) - Injection technique and site rotation schedule - Dose and administration frequency - Withdrawal periods for meat and milk (if applicable) - Personnel training requirements ### Step 4: Implement Record Keeping Maintain accurate records for each treated cow, including: - Cow identification number - Date of each rBST administration - Dose administered - Injection site location - Any observed adverse reactions - Milk production data before and after treatment ### Step 5: Monitor Cow Health and Production Track key health indicators for treated cows compared to untreated controls: - Clinical mastitis incidence - [Somatic cell](/blog/guides/somatic-cell) count trends - Conception rates and calving intervals - Body condition scores - Culling rates ### Step 6: Review and Adjust Regularly evaluate the economic and health outcomes of rBST use. Compare milk revenue gains against costs of the product, additional veterinary care, and potential milk price discounts. Adjust your protocol or discontinue use if health problems or economic losses outweigh benefits. ## Records and Measurements ### Essential Records for rBST Use | Record Type | Details to Include | Frequency | |-------------|-------------------|-----------| | Treatment log | Cow ID, date, dose, injection site, administrator initials | Each administration | | Health events | Mastitis cases, lameness, metabolic disorders, injection site reactions | As they occur | | Milk production | Daily or monthly milk yield per cow, bulk tank somatic cell count | Continuous | | Reproductive data | Breeding dates, conception results, pregnancy checks, calving dates | Per breeding cycle | | Feed intake | Group-level feed consumption, ration composition, feed efficiency calculations | Weekly or monthly | ### Measurements for Evaluating rBST Impact - Milk yield per cow per lactation (pounds or kilograms) - Peak milk production and lactation curve shape - Somatic cell count linear score - Clinical mastitis cases per 100 cow-months - Conception rate at first service - Calving interval (days) - Body condition score changes during lactation - Culling rate and reasons for removal ## Common Failure Patterns ### Inadequate Nutrition for Increased Production Failure to adjust the ration to meet the higher nutrient demands of rBST-treated cows can lead to negative energy balance, weight loss, and metabolic disorders. Farmers must work with a nutritionist to reformulate diets when initiating rBST use. ### Poor Injection Technique Improper injection technique can cause tissue damage, abscesses, and reduced product efficacy. Training all personnel in correct procedures and auditing injection sites regularly can prevent this failure. ### Ignoring Mastitis Monitoring Relying on bulk tank somatic cell counts alone may miss early signs of mastitis in treated cows. Individual cow somatic cell counts and clinical mastitis records are necessary for timely intervention. ### Failure to Communicate with Milk Buyer Assuming that all milk buyers accept rBST-treated milk can result in rejected loads and financial penalties. Verify acceptance in writing before starting treatment. ### Lack of Withdrawal Period Compliance Although rBST does not require a milk withdrawal period in the United States, some export markets or certification programs may impose restrictions. Check all applicable regulations and buyer requirements. ## Limitations and Professional Escalation Criteria ### Limitations of Available Research The scientific literature on rBST includes studies with varying designs, sample sizes, and outcomes. The meta-analysis published in 2024 provides a comprehensive overview, but individual farm results may differ. Farmers should interpret research findings in the context of their own management system and consult local experts. ### When to Escalate to a Veterinarian Contact your veterinarian if you observe any of the following in rBST-treated cows: - Unexplained increase in clinical mastitis cases - Drop in conception rates below herd targets - Persistent injection site reactions or abscesses - Signs of metabolic disease (ketosis, displaced abomasum, milk fever) - Unusual mortality or culling patterns ### When to Escalate to a Nutritionist Engage a nutritionist if: - Treated cows lose body condition despite adequate feed intake - Feed efficiency declines after initial improvement - Rumen health problems (bloat, acidosis) increase - Milk composition changes significantly ### When to Escalate to a Regulatory or Certification Body Contact your milk buyer, certifying agency, or state department of agriculture if: - You are uncertain about rBST labeling or certification requirements - You need guidance on export market restrictions - You suspect non-compliance with organic or rBST-free certification ## Practical Decision Framework for rBST Use: A Herd-Level Economic and Health Assessment Tool Deciding whether to use rBST requires a structured evaluation that integrates herd health data, market conditions, and financial projections. A systematic decision framework helps farmers avoid common pitfalls and make evidence-based choices that align with their specific operation. The following framework is designed for use during the dry period before the next lactation cycle begins, allowing time for protocol development and staff training. ### Step 1: Herd Health Baseline Assessment Before considering rBST, establish a 12-month baseline for key health indicators using your herd management software or paper records. Calculate the following metrics for your herd: - Clinical mastitis incidence rate (cases per 100 cow-months) - Bulk tank somatic cell count (SCC) monthly average - First-service conception rate (percentage) - Calving interval (days) - Body condition score (BCS) at peak lactation and at dry-off - Culling rate for health reasons (percentage) Compare these values to breed averages and your own herd targets. If mastitis rates exceed 25 cases per 100 cow-months or first-service conception rates fall below 35 percent, address these issues before adding rBST. The Merck Veterinary Manual provides reference ranges for dairy cattle health parameters that can guide this assessment. ### Step 2: Market Access Verification Contact your milk buyer in writing to confirm their current policy on rBST-treated milk. Request a written statement that includes: - Whether rBST-treated milk is accepted without restriction - Any premium or discount applied to rBST-free milk - Documentation requirements for rBST-free certification - Testing protocols for rBST residues if applicable If you supply multiple processors, determine whether separate storage and hauling of rBST-treated and untreated milk is feasible. Some cooperatives commingle milk, making segregation impossible. Document all communications and retain copies for your records. ### Step 3: Economic Projection Model Develop a partial budget that compares expected revenue and costs with and without rBST. Use your own herd data and current market prices. Include the following line items: **Additional revenue with rBST:** - Increased milk sales (pounds per cow per lactation multiplied by milk price) - Any premium for rBST-free milk if you choose not to use the product **Additional costs with rBST:** - Product cost per dose multiplied by number of treatments per lactation - Increased feed costs (estimate 10-15 percent higher energy requirements) - Additional veterinary and treatment costs for expected health events - Labor for injection administration and record keeping - Potential milk price discount if your buyer penalizes rBST use **Net change in profit per cow per lactation:** - Subtract total additional costs from additional revenue - Multiply by number of cows in the treatment group - Compare to projected profit without rBST Run the projection for at least two scenarios: conservative (lower milk response, higher health costs) and optimistic (higher milk response, lower health costs). The meta-analysis published in Research in [Veterinary Science](/blog/news/veterinary-science) in 2024 provides a range of milk yield responses that can inform your assumptions. ### Step 4: Risk Tolerance Evaluation Assess your operation's ability to absorb potential negative outcomes. Consider the following factors: - Debt level and cash flow flexibility - Dependence on a single milk buyer - Herd replacement availability if culling increases - Staff capacity for additional monitoring and record keeping - Insurance coverage for production losses If your operation has limited financial reserves or relies heavily on a buyer that may change its rBST policy, a conservative approach is warranted. Farmers with diversified markets and strong equity positions may have more flexibility to experiment with rBST in a subset of cows. ### Step 5: Pilot Group Protocol If the decision framework supports rBST use, implement a pilot program with a controlled group before full herd adoption. Select 10 to 20 cows that meet the following criteria: - Second lactation or greater - Body condition score between 3.0 and 3.5 at treatment initiation - No history of clinical mastitis in the current lactation - Confirmed pregnant or open less than 120 days - No metabolic disorders in the current lactation Assign an equal number of matched control cows that receive no rBST but are managed identically in all other respects. Treat the pilot group according to label directions, typically every 14 days starting at 57 to 70 days in milk. Record all data specified in the Records and Measurements section of this article. ### Step 6: Evaluation and Decision Point After completing one full lactation for the pilot group, compare outcomes between treated and control cows. Use the following decision rules: **Proceed with full herd adoption if:** - Milk yield increase exceeds 8 pounds per cow per day on average - Clinical mastitis incidence does not increase by more than 10 percent - First-service conception rate does not decrease by more than 5 percentage points - Net profit per cow increases by at least 5 percent **Discontinue or modify protocol if:** - Milk yield increase is less than 5 pounds per cow per day - Mastitis incidence increases by more than 20 percent - Conception rate drops by more than 10 percentage points - Net profit per cow decreases or remains unchanged **Escalate to veterinarian if:** - Any treated cow develops severe injection site reaction - Metabolic disease rate exceeds 10 percent in treated group - Mortality rate in treated group exceeds herd baseline by more than 2 percent Document all findings and decisions in your herd health records. Share results with your veterinarian and nutritionist to refine protocols for future use. ### Common Failure Patterns in Decision Making **Failure Pattern 1: Skipping the Baseline Assessment** Starting rBST without knowing your herd's current mastitis rate or conception rate makes it impossible to measure the product's impact. Without baseline data, you cannot distinguish normal variation from treatment effects. **Failure Pattern 2: Ignoring Market Signals** Some farmers assume their milk buyer will accept rBST-treated milk without verifying in writing. A policy change mid-lactation can force you to either stop treatment abruptly or lose your market. Always confirm in writing before the first dose. **Failure Pattern 3: Underestimating Feed Costs** The increased nutrient demand from rBST-treated cows requires ration adjustments. Failing to budget for additional feed can erode profit margins and lead to body condition loss. Work with a nutritionist to formulate a ration that supports the expected production increase. **Failure Pattern 4: Treating All Cows Uniformly** Not all cows respond equally to rBST. Older cows in good body condition typically show the greatest milk response, while first-lactation heifers and cows with health problems may not benefit. Use the pilot group to identify which cows are good candidates. **Failure Pattern 5: Neglecting Withdrawal Periods** Although the FDA does not require a milk withdrawal period for rBST in the United States, some export markets and certification programs impose restrictions. Check all applicable regulations before shipping milk from treated cows. The USDA and NRCS can provide guidance on compliance requirements. ### Records and Measurements for Decision Making Maintain a dedicated decision file that includes: - Herd health baseline report (12 months of data) - Written milk buyer policy confirmation - Partial budget calculations for two scenarios - Pilot group treatment and control records - Lactation summary for each pilot cow (milk yield, health events, reproduction) - Final decision and rationale Update this file annually or whenever market conditions or herd health status change significantly. The records support compliance with buyer requirements and provide documentation for certification programs. ## Frequently Asked Questions ### What is recombinant bovine somatotropin (rBST)? rBST is a synthetic version of the naturally occurring growth hormone somatotropin produced by a cow's pituitary gland. It is manufactured using [recombinant DNA](/blog/guides/recombinant-dna) technology and administered by injection to increase milk production in dairy cows. ### Is rBST approved for use in all countries? No. rBST is approved for use in the United States and several other countries, including Brazil and Mexico. It is banned in Canada, the European Union, Japan, Australia, New Zealand, and many other markets due to animal welfare concerns. ### Does rBST affect the safety of milk for human consumption? The FDA has determined that milk and meat from rBST-treated cows are safe for human consumption. However, some studies have examined potential risks, including a quantitative risk assessment of antimicrobial-resistant foodborne infections in humans due to rBST usage in dairy cows published in the Journal of Food Protection in 2017. ### What are the main health risks for cows treated with rBST? The most commonly reported health risks include increased incidence of clinical mastitis, reduced conception rates, injection site reactions, and metabolic disorders. Farmers must monitor treated cows closely and work with their veterinarian to manage these risks. ### Can I label my milk as rBST-free? Yes, if you do not use rBST and can document compliance. The USDA offers voluntary certification programs for rBST-free labeling. Some processors require third-party verification. ### What alternatives to rBST can increase milk production? Alternatives include genetic selection for higher milk yield and persistent lactation, nutritional management to optimize feed efficiency, improved herd health and comfort, and better reproductive management. These approaches do not involve exogenous hormones. ### How do I decide whether to use rBST on my farm? Evaluate your market requirements, herd health status, economic goals, and consumer preferences. Consult with your veterinarian and nutritionist. Consider starting with a small group of cows to assess the impact before full implementation. ### What records do I need to keep if I use rBST? Maintain treatment logs with cow identification, dates, doses, injection sites, and administrator initials. Also track health events, milk production, reproductive data, and feed intake. These records support management decisions and compliance with buyer requirements. ## Related Farming Guides - [Dairy Cattle Farming Nutrition Housing Health Signals And Herd Management](/knowledge/animal-farming/dairy-cattle/dairy-cattle-farming-nutrition-housing-health-signals-and-herd-management) - [Dairy Cow Cooling System Management](/knowledge/animal-farming/dairy-cattle/dairy-cow-cooling-system-management) - [Dairy Cow Culling Decisions And Records](/knowledge/animal-farming/dairy-cattle/dairy-cow-culling-decisions-and-records) - [How To Design A Comfortable Dairy Cow Barn](/knowledge/animal-farming/dairy-cattle/how-to-design-a-comfortable-dairy-cow-barn) - [Dairy Milk Quality Records And Bulk Tank Trends](/knowledge/animal-farming/dairy-cattle/dairy-milk-quality-records-and-bulk-tank-trends) ## Related Clinical & Scientific Guides * [Evaluating Feed Additives for Dairy Cow Performance](/knowledge/animal-farming/dairy-cattle/evaluating-feed-additives-for-dairy-cow-performance) * [Dairy Barn Fire Safety: Design and Prevention Measures](/knowledge/animal-farming/dairy-cattle/dairy-barn-fire-safety-design-prevention) * [Dairy Cow Pregnancy Loss Records and Review](/knowledge/animal-farming/dairy-cattle/dairy-cow-pregnancy-loss-records-and-review) ## References and Further Reading - [www.nrcs.usda.gov](https://www.nrcs.usda.gov/) - [www.merckvetmanual.com](https://www.merckvetmanual.com/management-and-nutrition) - [Effect of a single growth hormone (rbST) treatment at breeding on conception rates and pregnancy retention in dairy and beef cattle.](https://pubmed.ncbi.nlm.nih.gov/16183219). Animal reproduction science, 2006. - [Multiple protein biomarker assessment for recombinant bovine somatotropin (rbST) abuse in cattle.](https://pubmed.ncbi.nlm.nih.gov/23300820). PloS one, 2012. - [Lactation performance, feed efficiency, and blood metabolites of dairy cows treated with recombinant bovine somatotropin: A systematic review and meta-analysis.](https://pubmed.ncbi.nlm.nih.gov/38669867). Research in veterinary science, 2024. - [Lactation performance of Holstein cows treated with 2 formulations of recombinant bovine somatotropin in a large commercial dairy herd in Brazil.](https://pubmed.ncbi.nlm.nih.gov/28457552). Journal of dairy science, 2017. - [Public and farmer perceptions of dairy cattle welfare in the United States.](https://pubmed.ncbi.nlm.nih.gov/27179876). Journal of dairy science, 2016. - [Production performance of dairy cattle administered recombinantly derived bovine somatotropin (USAN, Somavubove) daily: a dose range study.](https://pubmed.ncbi.nlm.nih.gov/7956172). Domestic animal endocrinology, 1994. - [Quantitative risk assessment of antimicrobial-resistant foodborne infections in humans due to recombinant bovine somatotropin usage in dairy cows](https://doi.org/10.4315/0362-028X.JFP-16-404). Journal of Food Protection, 2017. - [Respiratory hypocapnia at different stages of lactation during long-term exogenous bovine somatotropin in crossbred holstein cattle in the tropic](https://api.elsevier.com/content/abstract/scopus_id/79960983778). Thai Journal of Veterinary Medicine, 2011. - [Tracing recombinant bovine somatotropin ab(use) through gene expression in blood, hair follicles, and milk somatic cells: A matrix comparison](https://doi.org/10.3390/molecules23071708). Molecules, 2018. > This article is educational and is not a substitute for veterinary diagnosis, treatment, public-health guidance, or regulatory reporting.