The cow generates 45% of her milk fat by synthesizing fatty acids (FA) from scratch inside the mammary gland, mainly using acetate produced in microbial fermentation. The rumen is nature’s primary way of making milk fat, and it is metabolically efficient and economically inexpensive. The complex feeds we give the modern dairy cow challenge the rumen to yield maximum acetate output. Rich carbohydrate (starch) increases microbial protein and milk lactose but pushes the rumen toward higher acidity and reduced acetate-production by fibrolytic bacteria. High-fat feeds are also tools to supply energy to the cow and supplementary FA for mammary milk fat synthesis. Fatty acids found in feed that are unsaturated (a.k.a. RUFAL) are vigorously biohydrogenated by bacteria to reduce the inhibitory effects of these FA on fermentation. Biohydrogenation is a unique metabolic process and can easily be derailed by imperfect rumen conditions, such as mild acidosis or microbial specie imbalances. Such “altered” biohydrogenation (Figure 1) can lead to formation of very small amounts of “trans-10” FAs that have direct, negative effects on the mammary gland fat synthesis. This is now accepted as the overriding cause of milk fat depression in dairy cows.
MFP® feed supplement supplies rumen available methionine as HMTBa, a molecule shown to maintain the diversity of rumen microflora and to help sustain normal biohydrogenation (Baldin et al., 2019; Pitta et al., 2020). MFP® improves microbial protein synthesis and reduces the activity of microbes associated with trans-10 FA production (Pitta et al., 2020). MFP® can provide an additional 0.2 to 0.3 lbs of milk fat when supplied at 0.12% of ration dry matter even when rumen conditions are slightly compromised. MFP® can also support milk fat production and avoid decline in high-risk rations containing higher levels of RUFAL (Baldin et al., 2018)
Economics of MFP® for Milk Fat
Milk fat continues to be a key economic driver for milk value. Many years of field application of HMTBa in typical dairy rations show that it will consistently provide more milk fat without reducing milk volume (Baldin et al., 2019). Supplementing 30 grams per cow daily of MFP® (0.12% of diet DM) can increase milk fat up to 0.3% with milk volume staying consistent.
Supplementing MFP® (30 g/hd/d) to cows producing 90 lbs of milk per day can bring a net ROI of 5:1 to your herd (Table 1).
References
Baldin, M., G.I. Zanton, and K.J. Harvatine. 2018. Effect of 2-hydroxy-4-(methylthio)butanoate (HMTBa) on risk of biohydrogenation-induced milk fat depression. J. Dairy Sci. 101:376-385. DOI: 10.3168/jds.2017-13446
Baldin, M., H.A. Tucker, and K.J. Harvatine. 2019. Milk fat response and milk fat and urine marker prediction of biomarkers of microbial nitrogen flow during supplementation with 2-hydroxy-4-(methylthio)butanoate (HMTBa). J. Dairy Sci. 102:6157-6166. DOI: 10.3168/jds.2018-15031
Pitta, D.W., N. Indugu, B. Vecchiarelli, M. Hennessy, M. Baldin, and K.J. Harvatine. 2020. Effect of 2-hydroxy-4-(methylthio) butanoate (HMTBa) supplementation on rumen bacterial populations in dairy cows when exposed to diets with risk for milk fat depression. J. Dairy Sci. 103:2718-2730. DOI: 10.3168/jds.2019-17389