Since the middle 1980’s the dairy industry has been sold a variety of soy products including hydrolyzed feathers, distiller’s grains and blood meal to optimize production of high producing cows. The theory by the makers of by-pass protein was that since solvent soybean meal had only 36% by-pass protein (protein that would not be utilized in the rumen), their product(s) would be rumen protected and digested in the small intestine.
These products, with by-pass protein values from 60% to over 70%, saw results that validated the manufacturers’ claims. These by-pass proteins were being fed from 1-5 lbs. per cow per day.
Total emphasis was placed on the products’ ability to by-pass the rumen, but total digestibility in the intestine was not known. Most of the by-pass products commanded premium pricing and this special by-pass protein industry has grown for the past 30 years. Some of these “hyped” products are deficient with rumen degradable protein. That degradable protein is critical for proper rumen function.
From the late 20th century and up to current times, the ethanol industry with their by-product of distiller’s grains has offered their product with high by-pass (74%). Considered a low-cost ingredient the ethanol distillers have provided an ingredient with corn-based amino acid profiles. This factor would limit feeding of distillers due to the commonly high levels of corn already being fed. Some of the challenges for the distillers are the variability of quality from a variety of sources.
Over the past 25 years, there has been naturally processed (hexane-free) soybean meal, that can provide highly digestible protein, a moderate level of by-pass protein (49.5%-52%) and a total tract digestibility of 94%. Extruded soybeans, followed by mechanical oil extraction can easily replace higher priced specialty by-pass proteins, soybean meal (solvent, hexane-processed), distiller’s grains and roasted products. In addition, the use of partially defatted extruded/expelled soybean meal can simplify dairy TMR mixes. This type of ingredient can be fed up to 8-9 lbs. per cow while eliminating many or all of these specialty protein products. In addition, it is not uncommon to see 3-5 lbs. milk/cow increases, milk fat and protein content also increases; all while lowering the total feed costs of $0.15-$0.20 per cow per day.
It appears that a number of the high by-pass products may be overpriced and over-hyped! Dairy producers could benefit financially from trying Soy Meal!!