Effect of processing high moisture ear corn on ruminal fermentation and milk yield

Area of Science:

• Animal Science
• Ruminant Nutrition
• Dairy Cattle Feeding

Background:

• Optimizing dairy cow diets is crucial for milk production and component yields.
• High moisture ear corn is a common energy source, but its physical form can impact digestibility and ruminal fermentation.
• Processing methods like grinding can alter feed characteristics and animal responses.

Purpose of the Study:

• To evaluate the effects of grinding high moisture ear corn and supplementing with expeller soybean meal on dairy cow performance.
• To assess the impact of these dietary changes on nutrient digestibility and ruminal fermentation parameters.
• To determine the optimal processing and supplementation strategy for lactating dairy cows.

Main Methods:

• Fifty-two multiparous and primiparous dairy cows were fed one of four diets varying in high moisture ear corn processing (rolled vs. ground) and soybean meal supplementation.
• Diets were formulated to be 53% alfalfa silage on a dry matter (DM) basis.
• Measurements included milk yield, milk component yield, dry matter intake (DMI), nutrient digestibility, and ruminal fermentation parameters (in vivo and in vitro).

Main Results:

• Grinding high moisture corn increased milk yield and component yields compared to rolled corn.
• Diet 3 (ground high moisture ear corn) resulted in the greatest DMI and 4% fat-corrected milk (FCM) yield.
• Grinding improved DM, organic matter, starch, and fiber digestibility, while reducing ruminal ammonia (NH3) concentration.
• Expeller soybean meal increased ruminal NH3 concentration.
• In vitro studies showed grinding decreased ruminal pH and increased volatile fatty acid (VFA) concentration.

Conclusions:

• Grinding high moisture ear corn enhances its utilization by lactating dairy cows.
• Processing high moisture corn by grinding stimulates ruminal fermentation, leading to improved nutrient digestibility and milk production.
• Dietary strategies involving ground high moisture corn can optimize energy utilization and performance in dairy cows.