Álvaro García
In cattle, the placenta prevents immunoglobulins from crossing from dam to fetus, leaving calves immunologically unprepared at birth. Their first real protection must come from colostrum, delivered in the very first feeding. Colostrum is a concentrated biological package designed to protect the calf during its most vulnerable window of life. Along with antimicrobial proteins and signaling molecules that support early gut development, it supplies immunoglobulin G (IgG), the primary antibody absorbed into the calf’s bloodstream and responsible for passive immunity.
Timing, however, is critical. The calf’s intestine can absorb intact antibodies only for a brief period after birth, and absorption declines rapidly as the gut closes during the first day of life. When colostrum quality is poor, intake is delayed, or volume is insufficient, passive transfer can fail, and the risk of disease rises sharply.
Most discussions of passive transfer focus on what happens in the maternity pen: harvesting colostrum cleanly, testing quality, delivering enough early, and verifying outcomes. That focus is justified. But colostrum quality itself is determined well before calving, during the dry period, when colostrogenesis is already underway.
A dry cow ration that may boost colostrum immunity
Dried distillers’ grains with solubles (DDGS), a co-product of ethanol production, are already common in dairy diets because they supply energy and protein, including rumen undegradable protein. DDGS also contain minerals such as sulfur and phosphorus, which can influence dietary cation–anion difference (DCAD), a central concept in transition cow feeding.
Lower DCAD diets during the dry period are widely used to support calcium metabolism and reduce the risk of metabolic problems around calving. The logic is straightforward: healthier transition cows eat better, transition better, and often produce better early lactation outcomes. But could that improved transition physiology also support better colostrum immune quality?
A 2025 study in The Veterinary Journal evaluated exactly whether replacing a portion of traditional concentrates with DDGS during the dry period could improve colostrum quality and strengthen passive transfer in calves.
Research findings on a commercial farm
On a commercial dairy in Poland, dry Holstein cows were assigned during the final three weeks before calving to one of four diets: a control total mixed ration (TMR), or rations containing 10%, 15%, or 20% DDGS on a dry matter basis. DDGS replaced portions of cereal meal and oilseed meals while diets were kept broadly similar for energy and protein supply. As DDGS increased, DCAD fell across treatments.
Colostrum was collected from the first full milking after calving. Calf blood was sampled on day 3 and day 30 to evaluate passive transfer, focusing on serum IgG and total protein.
Nutrition changed immunity, not calories
From a practical standpoint, one of the most useful findings was what did not change. Inclusion of DDGS did not shift colostrum’s basic composition, including fat, protein, lactose, dry matter, and urea. However, cows fed DDGS produced colostrum with higher immunoglobulin concentrations, including IgG, with the strongest improvement seen at the 15% inclusion level. Other immune factors also rose, including IgA and IgM, and key antimicrobial proteins such as lactoferrin and lactoperoxidase.
This matters because IgG concentration is only part of the calf health equation. Colostrum is also a gut health tool, and lactoferrin and related bio-actives help limit early microbial pressures in the newborn intestine.
In this study, calves from DDGS-fed cows had stronger early immunity signals. On day 3, calves from the 10% and 15% DDGS groups showed higher serum IgG compared with controls, indicating improved passive transfer. Total serum protein followed a similar pattern. By day 30, maternal antibodies declined across all groups as expected, but calves from the 15% DDGS treatment continued to show an advantage.
The practical implication is not that DDGS replace colostrum management; they do not. But the findings suggest dry cow nutrition can shift the odds in the calf’s favor by raising the immune value of the colostrum the calf receives.
What this means on farm
If you already use DDGS, this research adds a new reason to think about where they fit: not only as an economical protein and energy ingredient, but as a potential enhancer for colostrum immune quality.
Across this work, DDGS from 10% to 20% of dry matter improved immunological markers in colostrum without compromising basic composition, and 15% DDGS emerged as the most favorable inclusion for calf serum IgG outcomes.
The management message remains the same as ever: test colostrum, feed early, feed enough, and verify passive transfer. This study supports a broader perspective: calf immunity is shaped by what the cow eats during the dry period.
The full list of references used in this article is available upon request.
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