EAST EARL, Pa. — For many dairy producers across southeastern Pennsylvania, the 2025 forage crop “just isn’t feeding the same.” According to data shared during the recent Lancaster DHIA meeting, rainfall amounts and timing played a significant role, demonstrating why detailed forage testing is important.

Cliff Ocker of Rock River Laboratory, walked producers through forage analysis, linking lab results to weather patterns and feeding outcomes. Ocker was raised on a dairy farm in south-central Pennsylvania and spent 17 years as a dairy nutritionist before moving to the laboratory side of the industry, working closely with farmers, nutritionists and DHIA organizations to translate forage and feed testing data into practical feeding decisions.

From mid-May through mid-September, the region received about 29 inches of rainfall, above the roughly 24 to 25 inches typically needed to produce a high-quality corn crop. Much of that moisture arrived early in the growing season, before tasseling. Ocker said this timing can especially impact fiber digestibility. In fact, 9 inches in May and 11 in July covered two thirds of the total for the region over the growing season.

“Nutritionists started calling early in the season,” Ocker said. “Small grain silage and haylage weren’t feeding the same, now corn silage.”

Fiber digestibility down

Across forage types, Lancaster DHIA data showed a noticeable drop in 30-hour NDF digestibility (NDFD), particularly in corn silage, where digestibility dropped 6 to 7 points compared with recent years. Similar patterns appeared in haylage and small-grain silages, harvested earlier in the season.

While 30-hour NDFD is only one indicator, Ocker said it provides an early warning that forages may limit intake or milk production unless diets are carefully adjusted.

“Fiber digestibility is one of the most expensive things for a nutritionist to replace,” he said. “If it’s not in the forage, you end up chasing it with purchased feed.”

Ocker stressed that it matters more than crude fiber content. Two forages may look similar on paper, but the one with higher digestibility will support greater dry matter intake and milk production.

Beyond a single number

To better capture how forages actually perform in the cow, Ocker emphasized Total Tract NDF Digestibility (TTNDFD), a composite measure developed by the University of Wisconsin and implemented by Rock River Laboratory. It integrates multiple digestion time points, allowing producers and nutritionists to compare fiber utilization across forage types.

In 2025, Lancaster DHIA forage samples showed TTNDFD values similar to 2023, suggesting that while early digestibility suffered, total fiber utilization may still be manageable with proper ration formulation.

Ocker also pointed to undigestible NDF (UNDF 240) as another constraint. This is fiber that does not digest, even after 10 days in rumen fluid. Elevated UNDF limits intake and reduces flexibility in ration design.

“You can’t push intake with undigestible fiber,” he said. “And it’s very hard to compensate for it once the forage is in the bunker.”

Despite weather challenges, kernel processing scores (KPS) for corn silage averaged about 68%, similar to 2024 but still below the 70% benchmark associated with optimal starch utilization.

KPS measures how effectively kernels are broken during harvest. Scores above 70% improve starch digestibility and reduce fecal starch losses.

“If you’re hauling starch back out onto the field,” Ocker said, “that’s money lost.”

Ocker emphasized that forage testing should be paired with commodity testing. The region’s 2025 corn grain averaged 67 to 69% starch, below the commonly assumed 72%. Soybean meal also tested lower than expected, averaging about 45% protein as-fed instead of 48%.

“If you don’t test, you don’t know,” he said. “And if you don’t know, you can’t fix it.”

High-Oleic soybean option

Ocker also discussed high-oleic soybeans as a potential on-farm energy source. He explained that conventional soybeans are naturally high in linoleic acid, and when combined with other dietary fat sources in the ration, can increase the risk of milkfat depression. High-oleic soybeans shift some linoleic acid to oleic acid, which research shows can better support milkfat production.

For farms with available acrege, high-oleic soybeans may offer flexibility, but Ocker stressed the importance of fatty acid testing and proper processing to realize their benefits.

Testing drives profitability

From fiber digestibility to starch availability and fat utilization, Ocker’s message was consistent: assumptions are expensive.

“With today’s margins, you can’t afford to guess,” he said. “The data is there so you can use it.”