FROM THE FARM REPORT: HEALTH-FOCUSED MILK REPLACERS: WHAT PLASMA PROTEINS CAN — AND CAN'T — DO FOR CALVES

Scours and early-life disease remain among the most costly challenges in calf programs, driving labor, treatment costs, and long-term performance losses. While management practices such as colostrum quality, hygiene, and housing remain the foundation of calf health, nutrition — particularly milk replacer formulation — can influence how calves respond to disease pressure.

Some commercial milk replacers now include spray-dried plasma proteins as part of their protein blend. Plasma proteins contain bioactive components such as immunoglobulins (IgG, IgA, IgM), albumin, and peptides that can support gut integrity and immune function. Unlike traditional milk proteins, which primarily supply nutrients for growth, plasma proteins are designed to support health resilience, especially in young calves.

Several controlled studies in dairy calves report measurable health benefits when plasma proteins replace part of the whey protein in milk replacers. In a classic study by Quigley & Wolfe, 2003), calves fed milk replacers containing either porcine or bovine plasma experienced 70–80% lower mortality compared with calves fed whey protein concentrate. Diarrhea incidence was also reduced by 30–40%, with fewer total days of scours recorded.

More recent work supports these findings. (Henrichs et al., 2021) reported reduced morbidity and improved intestinal permeability markers in Holstein calves fed milk replacers containing spray-dried bovine plasma. Other studies have shown reduced medical treatments and fewer health interventions when plasma-containing milk replacers are used, particularly during the pre-weaning period (Morrill et al., 1995; Vasquez et al., 2017).

Importantly, these health benefits do not always translate into faster growth. In some studies, average daily gain was similar between plasma-based and whey-based milk replacers, while in others growth was slightly reduced when essential amino acids were not properly balanced. Research by Morrison et al., 2017) demonstrated that supplementing limiting amino acids alongside plasma protein helped maintain growth while preserving health benefits.

Evidence from other species strengthens confidence in the biological mechanism. In poultry and swine, plasma proteins consistently improve gut barrier function, reduce inflammatory signaling, and improve performance under disease or environmental stress (Moretó et al., 2020; Daneshmand et al., 2023). While calves are biologically different, the consistency of these responses across species suggests plasma proteins act primarily through gut health and immune modulation.

That said, it is important to be clear: the number of well-controlled plasma protein studies in dairy calves remains limited, and not all trials show the same magnitude of response. Differences in formulation, amino acid balance, disease pressure, and management conditions likely explain much of this variability. More large-scale, modern calf studies are needed to better define when and where plasma-containing milk replacers provide the greatest value.

Bottom line: Milk replacers containing plasma proteins can support calf health by reducing scours, lowering treatment rates, and improving resilience during early life. However, current evidence is based on a relatively small number of studies. Farmers should view these products as a health-focused option — particularly under higher disease pressure — and continue to ask for additional research and transparent data to guide future decisions.

— Marcos Marcondes

mmarcondes@whminer.com

— Kyan Zamaniyan

SUNY Plattsburgh student intern

* References available upon request