What Is Added to Non-Organic Milk? A Complete Guide

December 23, 2025 •

3 min read

Studies have shown that conventional milk samples can contain residues of pesticides and antibiotics, whereas organic samples do not. To understand what is added to non-organic milk, it is important to examine the distinct production practices that govern the conventional dairy industry.

Quick Summary

Conventional milk production methods may result in the presence of synthetic growth hormones, antibiotics, and pesticide residues. This article explores the specifics of these additives and their implications.

Key Points

Synthetic Hormones: Non-organic milk may come from cows treated with synthetic hormones like rBST to increase milk production, a practice banned in organic farming.
Antibiotic Residues: Conventional milk can contain low levels of antibiotic residues, while organic standards strictly forbid routine antibiotic use and selling milk from treated cows.
Pesticides in Feed: Conventional dairy cows are fed crops that may be treated with synthetic pesticides, resulting in detectable residues in the milk, unlike organic milk.
Farming Practices: Non-organic farming prioritizes productivity and may involve more confined conditions, whereas organic farming emphasizes animal welfare and pasture access.
Consumer Safety: Federal agencies set safety limits for antibiotic and pesticide residues in conventional milk, but trace amounts can sometimes be detected.

The Production Differences Between Organic and Non-Organic Milk

The fundamental difference between organic and non-organic, or conventional, milk production lies in the regulations and farming methods employed. Organic dairies must adhere to strict USDA guidelines, which prohibit the use of synthetic growth hormones, antibiotics, and non-organic feed. In contrast, conventional dairy farming prioritizes productivity and is not bound by these same restrictions, which allows for the use of certain additives and practices that influence the final product.

Synthetic Hormones: A Boost for Productivity

One of the most well-known differences is the use of recombinant bovine growth hormone (rBGH), also known as recombinant bovine somatotropin (rBST). This synthetic hormone is given to cows to increase milk production. It has been used since the 1990s and is a significant point of concern for some consumers. The use of rBST is strictly prohibited in organic dairy production, and many conventional brands now voluntarily label their products as being rBST-free due to consumer pressure. Research by Emory University found significantly higher levels of growth hormones and the related Insulin-like Growth Factor 1 (IGF-1) in conventional milk compared to organic milk.

Antibiotics and Antimicrobial Resistance

Conventional cows are often given antibiotics to treat or prevent infections, such as mastitis. While regulations require a withdrawal period to ensure milk is free from illegal residue levels before it is sold, trace amounts can still sometimes be detected. The overuse of antibiotics in livestock is a public health concern due to its potential to contribute to the growing problem of antimicrobial resistance. Organic standards, on the other hand, forbid the routine use of antibiotics. If an organic cow requires antibiotics for illness, it is removed from the organic herd and its milk is no longer sold as organic.

Pesticides and Non-Organic Feed

Unlike organic cows, which must be fed certified organic feed, conventional cows are fed crops grown using synthetic pesticides and fertilizers. Studies have found residues of current-use pesticides in non-organic milk samples. While these are generally within legal limits, some consumers choose organic milk to avoid these residues entirely. A 2019 Emory University study detected various pesticide residues in many conventional milk samples, but none in the organic samples tested.

A Closer Look at the Additives

This table provides a quick overview of the key differences related to additives and production methods.


Feature	Non-Organic (Conventional) Milk	Organic Milk
Synthetic Growth Hormones (rBST)	Permitted, used to increase milk yield.	Strictly prohibited by organic standards.
Antibiotics	Permitted for treatment and prevention.	Routine use is prohibited. Cow milk is discarded after treatment.
Pesticide Residues	Present in trace amounts due to conventional feed.	Not detectable (or at much lower levels) due to organic feed.
Feed	May include non-organic crops treated with pesticides and fertilizers.	100% certified organic feed, free of synthetic pesticides and fertilizers.
Pasture Access	Not a requirement, cows may be confined.	Required to have year-round access to pasture.

Processing Additives and Other Compounds

Beyond what the cow is given, additional additives can be introduced during the processing of milk and milk products. These include stabilizers, emulsifiers, and preservatives to extend shelf life and improve texture, especially in processed dairy items like powdered or condensed milk. Even fresh milk undergoes pasteurization, but some types of organic milk are ultra-pasteurized for an even longer shelf life. Conventional milk often contains higher levels of certain persistent environmental compounds, like legacy pesticides, which were banned but still exist in the environment.

Conclusion: Making an Informed Choice

The choice between non-organic and organic milk ultimately rests on a consumer's priorities regarding health, ethics, and environmental impact. While government agencies like the FDA assure that conventional milk is safe for consumption within regulated limits, the differences in production practices are clear. Non-organic milk can contain residues of synthetic growth hormones, antibiotics, and pesticides, which are absent or restricted in organic milk. This distinction is the primary reason some consumers are willing to pay the higher price for organic alternatives, prioritizing the absence of these specific compounds and supporting alternative farming practices. Regardless of the choice, milk remains a highly nutritious food. For more information on the guidelines for organic livestock, the USDA provides a comprehensive overview on their website.

USDA: Organic Livestock Requirements

Frequently Asked Questions

rBST (recombinant bovine somatotropin) is a synthetic hormone used in conventional dairy farming to stimulate increased milk production in cows. Its use is prohibited in organic farming.

Conventional milk may contain trace amounts of antibiotics used to treat illnesses in cows. However, milk is tested to ensure residue levels are within federal safety limits before it can be sold.

Yes, studies have found trace amounts of pesticide residues in conventional milk. These residues enter the cow's system through feed grown with synthetic pesticides.

Organic milk is free from synthetic growth hormones and antibiotic residues because USDA regulations prohibit their use in organic farming. Organic cows are also fed pesticide-free organic feed.

Not all non-organic milk contains rBST or antibiotics, as many conventional brands have voluntarily stopped using rBST. However, conventional cows are treated with antibiotics when needed, and the feed may expose them to pesticide residues.

According to the FDA, conventional milk is safe to drink. The agency has regulations and testing protocols in place to ensure that any residues of drugs or pesticides are within safe, legal limits for human consumption.

Non-organic production often focuses on maximizing efficiency and yield. This can involve confined conditions and specific feeding regimens that are not permitted under organic animal welfare standards.