The following is a trial based on a study by Iowa State University using our specific proprietary protease enzyme, Rumagentin, which is a specific portion of our enzyme package found in our best-selling product NutriZyme. Rumagentin was proven extremely effective in proving feed conversions. In the following study, Dr. Lance Baumgard and his team, found that the ration of cost was lowered by removing bypass proteins with the milk flow remaining at the same level, and the feed intake dropped approximately 2 pounds per cow. This trial was also published in the Italian Journal of Animal Science.

The Rumagentin Study

The enzymes naturally produced in the rumen can’t get to all the feed to break it down, so what do we do with the rest? Let it go to waste? That’s where NutriZyme’s main ingredient Rumagentin excels. All that feed and valuable protein would otherwise go to waste and be expelled in the feces. The specific blends of protease enzymes in NutriZyme/Rumagentin add the extra digestive power to breakdown and extract the otherwise unusable protein material from feed.

Rather than paying to add additional protein material to the feed for rumen bypass, NutriZyme is designed to extract existing proteins and amino acids to make the most of the feed you have already purchased.

Dry matter intake (DMI) is fundamentally important in animal nutrition because it establishes the baseline amount of nutrients available to the animal. This does not follow that all the nutrients are extractable and will be utilized. Every biological system is, to some degree, inefficient. Meaning, that processes never work at 100% efficiency and therefore generates waste. In animals, the undigested DMI is simply expelled in the feces. In order to counteract this problem, many products have been designed to add additional nutrients, specifically rumen bypass proteins to the feed. NutriZyme takes a different, more efficient approach. Why not utilize the existing nutrients and proteins in the DMI already being fed? A specifically designed blend of proteases was developed for this purpose. Acting to target the specific protein material within DMI, NutriZyme acts to release more protein and amino acids from the feed so the body may more efficiently absorb the nutrients.

A field trial at Iowa State University, demonstrated the improved feed efficiency of NutriZyme’s “Rumagentin”: On a trial of 96 cows matched by parity, days in milk and previous milk production, the control and experimental groups were formed. After feeding 4g/cow/day for a 21 day experimental period, there was a 7 day washout prior to switching control and treatment groups for another 21 day experimental period. The results of the experimental and control groups were then compared, statistically analyzed, and are listed in the following table.

Download PDF Versions of Iowa State Study and info published in Italian Journal of Animal Science

Iowa State Study 2012

Italian Journal of Animal Science Article

In a time where saving and efficiency is becoming increasingly important in a struggling economy, Nutrizyme provides a novel, cost-efficient alternative to expensive rumen bypass proteins already on the market. Designed to extract more amino acids from the same amount of DMI, Nutrizyme improves amino acid extraction and has been shown to significantly decrease overall DMI.

Nutrizyme, along with proper DMI or feed blend can help improve nutrition and give you more product for your dollar. Compared to other marketed rumen bypass proteins, Nutrizyme is offered at approximately 30% less cost. The question then is not “Can I afford it?” but, rather “Can I afford to not use Nutrizyme?”

“Determining the Effectiveness of Microbial Protease on Production Variables in Lactating Holstein Cows”


Feed Sources Specific Protease Enzyme Blend (Rumagentin) used in our product   


Lance H. Baumgard – Iowa State University
Ekin Sucu – Iowa State University
Amir Nayeri – Iowa State University
Maria Victoria Sanz-Fernandez – Iowa State University
Nathan Upah – Iowa State University


Summary and Implications

Lactating Holstein cows were assigned to a control diet or a diet containing a blend of supplemental protease enzymes (Rumagentin™, Feed Sources LLC, Alta Loma CA) at the Iowa State University Dairy farm. Study objectives were to examine the effects of proteases on milk yield, milk composition, feed intake and feed efficiency in lactating Holstein cows. Our results indicate that protease enzymes enhanced feed conversion efficiency and nitrogen utilization of dairy cows.


Commercial enzymes are a tool to enhance the efficiency of livestock production. The inclusion of enzymes for ruminant diets has primarily centered on fibrolytic enzymes. However, protein is typically the most expensive component in dairy rations. In addition, the plant protein is sometimes less degradable and can vary based on plant type, maturity and protein matrix. Recently, a number of in vitro studies have demonstrated that proteases increased dry matter and NDF digestibility of alfalfa hay and rice straw. On the other hand, little work has evaluated the impact of protease enzymes in ruminants, and specifically dairy production variables.

Materials and Methods

Ninety-six lactating Holstein cows (2.7 ± 1.6 parity, 153.8 ± 103.7 days in milk, 40.3 ± 5.9 kg milk/d, 624 ± 62 kg BW) were housed in a free-stall barn (ISU Dairy) and assigned to one of two treatments. Cows were milked twice daily (0800, 2000 h) and milk yields were recorded at each milking. All cows were fed a total mixed ration (TMR) once daily (0730 h) and orts/weigh-backs were recorded prior to morning feeding (0630 h). The diet primarily consisted of corn silage, alfalfa hay and concentrate. The TMR did not contain supplemental by-pass protein (e.g. Soyplus, Soybest, blood meal) and was formulated by Dairy Health Services (Sanborn, IA) to meet or exceed the predicted requirements (NRC, 2001) for energy, protein, minerals and vitamins. All procedures were reviewed and approved by the Iowa State University Institutional Animal Care and Use Committee.

Cows were split into four pens (24/pen) and fed diets with or without supplemental protease enzymes (Rumagentin™, Feed Sources LLC, Alta Loma CA) during two 21 d periods in a continuous random cross over design. There was a 7 d adaptation period to the control diet without bypass protein. During the first period (P1), half the cows (2 pens) received the treatment diet (control plus

Rumagentin™) while the other half (2 pens) received the control diet. After P1, there was a 7 d washout period in which all cows (4 pens) received the control diet. During the second period (P2), treatment assignment switched: cows that received the treatment diet in P1 received the control diet and vice versa. The granular form of enzymes was mixed with a ground-corn carrier (Mid-State Milling State, Center, IA). Ground corn was added to the TMR (at mixing) at a rate of 0.91 kg/cow/d and contained either the enzyme or the control treatment (plain ground corn) to provide product at a level of 4 g/head/d. Feed efficiency was calculated using solids corrected milk yield/dry matter intake.

Milk samples from each cow were collected during the a.m. milking on d 15, 17, 19 and 21 relative to treatment initiation during both periods. Samples from each collection were stored at 4°C in vials containing a preservative (bronopol tablet; D&F Control System, San Ramon, CA) until analysis. Samples were analyzed by Dairy Lab Services (Dubuque, IA) using AOAC approved infrared analysis equipment and procedures for milk components.

Blood samples were obtained via coccygeal venipuncture during both periods on d -1 and 21 relative to treatment initiation using heparinized vacutainer tubes (Becton Dickinson, Franklin Lakes, NJ). Plasma was harvested following centrifugation at 2100 x g for 15 min, and subsequently stored at -20°C until analysis. Plasma was analyzed for blood urea nitrogen by an enzymatic colorimetric method using a commercial kit (Teco Diagnostics, Anaheim, CA).

The effects of treatment on pen feed intake, feed efficiency, milk yield, and milk components were analyzed using the PROC MIXED procedure of SAS (SAS Inst. Inc. Cary NC), with week as a repeated measure and pen (treatment) as the random statement. Pen was the experimental unit on all analyzed data. All data were covariately adjusted using their respective presupplementation values (d -7 to -1). Results are reported as least squares means and in all cases, differences among means were declared as significant at P < 0.05, whereas trends were discussed at P < 0.10, unless stated otherwise.

Results and Discussion

Supplemental protease-fed cows had reduced dry matter intake (0.93 kg/d; P < 0.05) compared to cows fed control diets (Table 1). There was a tendency (P = 0.06) for an increased (5.37%) feed efficiency (SCM/dry matter intake (DMI)) in the protease-fed cows compared to control cows. However, gross feed efficiency (milk yield/DMI) did not differ between treatments (P = 0.14). The decreased feed intake and thus increased feed efficiency could be due to increased fiber digestion in the rumen. Protease enzymes may decrease cell wall proteins, enabling faster access to fiber by the rumen microorganisms. Lactation performance, milk composition and blood parameters are presented in Table 2. There were no differences in production parameters between treatments (P > 0.05). However, protease-fed cows had lower concentration of blood urea nitrogen (BUN; 10.02%; P < 0.05) and tended to have higher milk lactose (0.06%; P = 0.08), lower milk urea nitrogen levels (MUN; 3.4%; P = 0.10), and lower somatic cell score (SCS; 3.7%, P = 0.10) in comparison to the control fed cows. The improved BUN and MUN status may have been due to increased nitrogen utilization in response to protease supplementation.


We gratefully acknowledge the contributions of the staff at the Iowa State University Dairy Farm and financial contributions from Feed Sources LLC.