MFP® Feed Supplement is a source of dietary methionine in the molecular form of HMTBA. Research has demonstrated that feeding HMTBA to lactating dairy cows increases the yield of milk fat and milk protein in a dose-dependent manner (Zanton et al., 2014). Recent studies highlight some of the specific benefits of HMTBA on the production of rumen microbial protein and blood plasma methionine concentrations in dairy cattle.
Effect of HMTBa on Rumen Microbial Protein Yield
- Rumen microbial protein is the largest single source of metabolizable (absorbed) protein for the dairy cow, comprising at least 50% of the total supply. Rumen microbes use energy from digestible carbohydrates and multiple sources of nitrogen, including non-protein nitrogen, to produce microbial protein with an excellent amino acid profile to support milk production. Therefore, an increase in microbial protein supply is highly beneficial both nutritionally and economically to the dairy cow and the dairy producer.
- Research conducted at Penn State University (Lee et al., 2015) on multiparous Holstein cows showed that feeding HMTBA at 0.12% of diet dry matter increased the daily production of microbial crude protein (CP) by 162 grams (Figure 1). This equates to an increase of 100 grams of metabolizable protein (MP) per day available to the cow (NRC Nutrient Req. Dairy Cattle, 2001).

- The current value of metabolizable protein from common feed ingredients and forages is $0.40 per pound (Progressive Dairy, 9/12/21 based on Ohio State SESAME software). Therefore, an increase of 100 grams metabolizable protein per day is worth $0.09 per cow per day.
- In addition to the documented increase in milk fat production, feeding 30 g/day MFP® to supply 0.12% HMTBA in the diet dry matter allows the nutritionist to reduce the metabolizable protein requirement by 100 g/day resulting in a reduction in feed costs.
Effect of HMTBA on Plasma Methionine Concentrations and Milk Protein Yield in Dairy Cows
A meta-analysis of 39 studies published between 1970 and 2018 (Feng et al., 2018) reported that feeding HMTBA significantly increases blood methionine concentrations in dairy cows. For each gram of HMTBA fed, there was an increase of 0.41 μM plasma methionine. Therefore, feeding 25 grams of HMTBA (30 g MFP®) per day is predicted to increase blood methionine concentration by 10 μM (micromole/L). The linear response of plasma methionine when feeding HMTBA is similar to what is seen when D-L methionine is infused post-ruminally in lactating cows (Pisulewski et al., 1996). HMTBA has a rumen escape value of 40% (Koenig et al., 2002) and is subsequently converted into L-methionine by body tissues (Lapierre et al., 2011).
A prior analysis (Zanton et al., 2014) found that for each gram of HMTBA fed, milk protein was increased by 0.7 grams per day. Based on this analysis feeding 30 g/day of MFP® would increase milk protein yield by 0.04 lbs per day is worth $0.12* per cow per day. Adding the value of increased metabolizable protein ($0.09), feeding HMTBA at 0.12% of diet dry matter provides $0.21/cow/day in total protein value to the dairy producer.
Supplying HMTBA via MFP® Feed Supplement, at a cost of $0.13/cow/day, returns value to the dairy producer with increases in milk fat and milk protein production and an ROI of 6:1*.
*Based on October 2021 U.S. milk fat and milk protein prices.
References
Feng, X, R.R. White, H.A. Tucker, M.D. Hanigan. 2018. Meta-analysis of 2-hydroxy-4-methylthio-butanoic acid supplementation on ruminal fermentation, milk production, and nutrient digestibility. J. Dairy Sci. 101: 7182-7189. https://doi.org/10.3168/jds.2017-13847
Koenig K.M., Rode L.M., Knight C.D., Vazquez-Anon M. 2002. Rumen degradation and availability of various amounts of liquid methionine hydroxy analog in lactating dairy cows. J. Dairy Sci. 85: 930-938.
Lapierre, H., M. Vázquez-Añón, D. Parker, P. Dubreuil, G. Holtrop, G.E. Lobley. 2011. Metabolism of 2-hydroxy-4-(methylthio)butanoate (HMTBA) in lactating dairy cows. J. Dairy Science 94: 1526–1535. https://www.journalofdairyscience.org/article/S0022-0302(11)00106-8/fulltext
Lee, C., J. Oh, A.N. Hristov, K. Harvatine, M. Vazquez-Anon, G.I. Zanton. 2015. Effect of 2-hydroxy-4-methylthio-butanoic acid on ruminal fermentation, bacterial distribution, digestibility, and performance of lactating dairy cows. J. Dairy Sci. 98: 1234-1247. https://doi.org/10.3168/jds.2014-8904.
National Research Council. Nutrient Requirements of Dairy Cattle. 2001.
Progressive Dairy, September 12, 2012. P4. Article by White, A. Ohio State University.
P. M. PISULEWSKI,' H. RULQUIN,* J. L. PEYRAUD, R. VERITE. 1996. Lactational and Systemic Responses of Dairy Cows to Postruminal Infusions of Increasing Amounts of Methionine. J. Dairy Sci. 79:1781-1791
Zanton, G.I, G.R. Bowman, M. Vázquez-Añón, L.M. Rode. 2014. Meta-analysis of lactation performance in dairy cows receiving supplemental dietary methionine sources or postruminal infusion of methionine. J. Dairy Scii. 97: 7085-7101. https://doi.org/10.3168/jds.2014-8220