A paper scheduled for the October 2026 issue of the Journal of Dairy Science ties the season a calf is born to measurable differences in prenatal tissue development and early postnatal growth. Colostral fat content acts as a secondary modifier of that trajectory, according to the article title.

The work — "Season of birth shapes prenatal tissue development and early postnatal growth in calves, with secondary modulation by colostral fat" — appears in Volume 109, Issue 10 of the journal. Authors are Maximilian A.E. von Riedheim, Hannes Erkinger, and Josef J. Gross. The Journal of Dairy Science is the peer-reviewed flagship publication of the American Dairy Science Association, the main U.S. professional body for dairy research.

What does the title actually say?

The phrasing carries two layered claims. First, the calendar date a calf enters the world shapes both the tissue that forms before birth and the growth curve in the early postnatal window. Second, the fat fraction of colostrum — the antibody- and energy-rich first milk — adjusts that seasonal signal without overriding it. "Secondary modulation" tells readers the authors measured colostral fat and found it informative, but placed it below the primary seasonal driver in their model. That sequencing is the title's clearest signal of how the authors ranked the two effects.

Why does birth season matter for calves?

Dairy producers and veterinarians already manage calves around season by default. Summer heat stress in dry cows is documented to lower birth weight and shift organ development in the calf. Winter cold raises the energy demand on the cow producing colostrum and changes the composition of that first milk. The von Riedheim et al. paper sits inside that established research lane, asking whether seasonal patterning shows up across the calendar, not only at the temperature extremes. The phrase "prenatal tissue development" indicates the work looks at organ and adipose patterning in utero, rather than birth weight alone.

Where does colostral fat fit?

Colostrum management is a standard checkpoint on most dairy operations. Brix refractometers grade immunoglobulin content; fat percentage is often tested alongside, sometimes by Gerber or Babcock methods, sometimes by infrared analyzers. Fat in colostrum carries both energy for the newborn and fat-soluble vitamins; variation in that fat fraction is partly driven by the cow's dry-period diet and the timing of colostrum harvest. The paper's framing of colostral fat as a "secondary" lever tells practitioners that the authors treated it as a modifier worth measuring, not the headline variable. That ranking matters for any herd thinking about where to invest in colostrum testing.

What does this change at the farm level?

If birth season predicts specific tissue or growth outcomes, dry-cow management and calving protocols can be tuned in advance. If colostral fat independently shifts early growth, the operational lens widens onto colostrum quality testing and the timing of first feeding, which most herds target within six hours of birth. The full paper — sample size, breed, herd structure, statistical thresholds, and the colostral fat range tested — sits inside the journal article. The title alone signals a research direction: from documenting that season matters toward naming the biological levers practitioners can act on.

What to watch next

The October 2026 release in Volume 109, Issue 10 is the authoritative source for the numbers. Producers and veterinarians should expect related work on colostrum-based interventions to follow, given the journal's regular coverage of calf nutrition. Regulatory status for any new feed or colostrum-supplement product falls under FDA CVM in the United States and the European Food Safety Authority in the EU; the paper itself does not introduce a regulated product. The question worth tracking is whether the seasonal effect size and the colostral fat effect size reported in the full text are large enough to shift standard operating procedures on commercial dairies.