Feeding Waste Milk Safely Boosts Calf Growth

By Blake Jackson

Feeding calves non-saleable or waste milk from treated cows or those with high somatic cell counts (SCC) is a common practice on many dairy farms.

Using this milk helps keep high SCC cows out of the bulk tank, improving overall milk quality and allowing farmers to earn premiums for low-SCC milk.

Milk from cows under antibiotic treatment cannot be sold during the withdrawal period, so feeding it to calves provides a practical use and reduces reliance on milk replacer.

Studies have shown no significant difference in average daily gain between calves fed waste milk and those receiving bulk tank milk. Other research indicates calves fed waste milk often achieve higher weaning weights and are less likely to require treatment compared with those on milk replacer, making it a cost-effective option.

High SCC in cows can also impact colostrum quality. Cows drying off with subclinical mastitis are more likely to experience stillbirths, and colostrum from high-SCC cows tends to have lower IgG concentrations (Gulliksen et al., 2008; Pasatorini et al., 2025).

Monitoring colostrum quality with tools like a BRIX Refractometer is essential. Low-quality colostrum should be supplemented or replaced with high-quality colostrum or colostrum replacer to ensure adequate immunity transfer.

Waste milk from treated cows may contain antibiotic residues, which can increase antibiotic resistance in calves (Foutz et al., 2018; Langford et al., 2003). Studies also link antibiotic residues in milk to higher incidences of scours in calves (Flynn et al., 2025).

Pasteurizing waste milk and colostrum helps reduce pathogens, including Mycoplasma, and can lower disease and mortality rates (Butler et al., 2000; Armengol and Fraile, 2016). Milk should be refrigerated if not fed immediately, as bacterial growth can occur quickly.

Colostrum can be stored in the refrigerator for up to seven days or frozen for up to a year. Feeding milk promptly after pasteurization is crucial to prevent bacterial proliferation.

By following proper management and pasteurization practices, feeding waste milk can be a safe, economical, and effective strategy for raising healthy calves.

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