Rumen-protected fats support cow health, milk production while providing a ‘safe’ source of energy in dairy rations. Dr. Richard Kirkland of Volac Wilmar Feed Ingredients explains how.
Dairy farmers and nutritionists often walk a tightrope when balancing energy supply in rations without destabilising rumen function. Get it wrong, and cow health, fertility and milk production can all suffer. According to Dr. Richard Kirkland, Global Technical Manager for Volac Wilmar Feed Ingredients, rumen-protected fat supplements are ideal for maintaining this balance by delivering a safe, concentrated energy source that supports overall cow performance.
Below, he outlines four ways rumen-protected fats provide dairy rations with a source of safe energy:
1.They pass through the rumen while avoiding disruption to fibre
A key feature of rumen-protected fat supplements is their ability to pass through the rumen to deliver nutrients directly to the small intestine. This avoids the negative effects of rumen-active oils on fibre digestion, maintaining rumen function and improving supplement utilisation. Megalac provides rumen-protection by the formation of calcium salts with fatty acids.
“While a protected fat passes through the rumen with minimal degradation, the opposite happens when ‘unprotected’ fat sources, such as vegetable oils or high-fat byproducts like brewers grains, are fed. These unprotected fats coat feed particles, inhibiting fibre digestion and throwing off rumen pH,” explains Dr. Kirkland. “This leads to feed efficiency loss, but most critically, puts the animal at high risk of acidosis and significant performance loss, in particular a fall in milk fat.”
Volac Wilmar’s manufacturing process for Megalac takes this further, producing calcium salts with larger particle sizes that improve rumen protection compared to other sources.
“We manufacture rumen-protected fats for two reasons,” says Dr. Kirkland. “The first is to protect the rumen from the fat, avoiding reductions in fibre digestibility. The second is to protect the fat from the rumen to avoid biohydrogenation of unsaturated fatty acids, ensuring they pass to the small intestine for functional benefit.”
2.They supply high energy density without increasing acid load
Fat is highly energy-dense, with 500g of Megalac increasing energy density by 0.5 MJ/kg Dry matter. Compared to cereals, it contains over 2.5-times the energy while maintaining rumen function.
“Fat offers flexibility in ration formulation by allowing higher energy density diets without adding to the acid load in the rumen. Cereals like corn, barley, and wheat ferment quickly, producing acid, which lowers rumen pH — increasing acidosis risk,” states Dr. Kirkland.
3.They reduce heat generation
Because fats are relatively ‘simple’ molecules and don’t ferment in the rumen, heat generation during digestion is minimal compared to other feed sources, making them particularly ideal in hot climates to reduce internal heat production, which otherwise adds to heat stress.
“Fat is considered a ‘cool’ nutrient because it produces minimal heat during digestion and metabolism. Its high metabolic efficiency helps offset lower Dry matter intake during heat stress, helping cows meet energy requirements even when appetites decrease,” says Dr. Kirkland.
4.They support targeted performance
Research and on-farm results show that rumen-protected fat is more than a rumen-safe, energy-dense ingredient; it is a strategic tool to target specific performance outcomes.
C16:0 boosts milk fat production, but it is recognised that part of this effect may be at the expense of body fat and condition. In contrast, C18:1 enhances total diet fat digestibility, energy supply, body condition and fertility, supporting reproductive and metabolic health in early lactation.
“This unique ability to target nutrients toward different areas of cow performance at different lactation stages ensures a cow’s energy demands are met to protect her health and performance,” concludes Dr. Kirkland. “Rumen-protected fat supplements are an effective tool to provide highly concentrated energy without compromising rumen health, supporting milk production, body condition, fertility and overall performance in a safe, efficient way.”
