Dairy Senior Scientist and Technical Advisor
Many dairy farms are using whey products from cheese manufacturing plants as a source of energy in the ration. One primary reason is its economical price. The dry matter content of whey products fed on the farm is also low, ranging from 10 to 30%. One misconception is that a dairy farm can only feed one “liquid” product type. In reality, comparing QLF molasses products to whey is like comparing apples to oranges. They serve different purposes in rumen digestion and animal performance. Farms that are already feeding whey can benefit from feeding a QLF supplement. Many QLF customers are feeding both types of products. They benefit from the economical source of whey energy and the responses of enhanced rumen fermentation and milk components from feeding QLF.
Here are the top reasons that QLF molasses-based supplements differ from whey and how QLF can complement the feeding of whey.
- Different Dry Matter: The dry matter content of whey products fed on the farm is usually around 10 to 30%, while the dry matter of a typical QLF product is around 60-65%, much higher than the dry matter of a TMR. Feeding whey adds moisture to the TMR, while feeding QLF products adds stickiness and palatability, and reduces sorting.
- Different Fermentation Characteristics: Sucrose, glucose, and fructose in QLF molasses products ferment rapidly in the rumen, within the first few hours of consumption. This fast fermentation jump-starts rumen bugs, and they also utilize free N and soluble protein, converting into more microbial protein. This is typically seen as reduced MUN, indicating a more efficient fermentation. On the other hand, whey products have a slower fermentation speed (more similar to starch from corn) and do not stimulate microbial protein as sugars in molasses will do. Because of the different fermentation speeds, feeding both products could complement each other by covering a wider range of fermentation pools of carbohydrates.
- Fiber Digestibility Response: Sugars in QLF supplements are naturally occurring in plants. Rumen bugs have evolved to ferment and utilize these sugars effectively. Lactose in whey products is not naturally exposed to mature ruminant animals, and they do not have the same effect on stimulating fiber-digesting bacteria. Research consistently shows the benefits of feeding molasses on increasing fiber NDF digestibility. The response is even stronger on a high-forage diet. Every one-unit increase in NDF digestion equals an average 0.51 lb increase in milk yield. It is common to see an 8 to 10-unit increase in NDF digestion in response to feeding molasses-based products. This was also published by the USDA Dairy Forage Center a few years ago.
- Milk Component Response: Most farms feed QLF products for the benefits of increased milk fat and protein yields. Improved rumen microbial production from supplemental sugars results in greater rumen microbial protein that is balanced in amino acid profile to support milk protein synthesis. Improved fiber fermentation results in more VFA production such as acetate and butyrate, the key building blocks of milk fat. In a published meta-analysis on feeding sugar, with 5-7% DM added sugar, cows increased fat-corrected milk by 4.7 lbs/d (83.1 vs. 87.8 lbs). Whey products are typically used as cheap energy to partially replace corn, rather than for the benefits of milk components.
- TMR Bunk Life and Heating: Because of the high water content and the potential microbial population, whey products tend to heat the TMR in the bunk in the summer months. In contrast, QLF supplements are very stable with some ingredients within to aid handling and shelf life. We also have many customers who choose to add organic acid products through QLF in the summer months to control heating and extend bunk life.
- Shelf Life, Contamination, and Consistency: The shelf life of whey products is short, especially in summer hot months. Wild yeast and other microbes could grow inside the storage tank, which could hurt rumen microbial populations and decrease milk production and components. In cold winter, whey products can freeze up if not utilized quickly. Consistency is also a concern as separation can occur and due to the nature of cheese manufacturing, moisture, lactose, and mineral contents oftentimes fluctuate from load to load. In contrast, QLF supplements are manufactured and guaranteed consistency, a foundation for stable rumen fermentation and high milk components.
- Customization of Protein, Additives, and VTM: QLF supplements not only provide valuable fermentable sugars, but they can also provide the addition of soluble protein, vitamins, and minerals. Many farms feed QLF products with 15 to 20% CP. The added NPN, together with fast fermenting sugars, drives rumen microbial production, resulting in higher microbial protein compared to feeding sugars alone. Many nutritionists will choose to deliver the VTMs and/or other small inclusion rate additives through QLF, an excellent carrier to suspend and distribute those expensive additives and minerals.
- Feeding based on Lactation Stages: Because of the above-mentioned concerns of feeding whey, we rarely see nutritionists suggest farms feeding whey products to transition cows, it is not worth the risk. They have confidence in feeding QLF supplements to those pre and post-fresh groups because they know the quality and benefits of these supplements on transition cows. If both sugar sources are on the farm, a recommendation would be to feed QLF supplements to pre-fresh, fresh, and high lactating groups to maximize their milk potential. Consider feeding lactose whey products to late cows to replace some corn as their production decreases. This is an example where both products can complement each other in a herd.
Based on the reasons mentioned above, comparing QLF supplements to whey products is truly like comparing apples to oranges. Just because they are both “liquid,” some people have the misconception that they can only feed one or the other. They are used for different reasons and they serve different purposes. A farm can be successful by feeding both products, capturing the benefits of whey as a least-cost energy source, and improving milk component responses from feeding QLF supplements.