Prediction of the energy value in colostrum and transition milk of Brown Swiss cows

Ostendorf C.S., Vorndran A.M., Meyer A., Steinhoff-Wagner J.

Benutzer: Gast

Titel:: Prediction of the energy value in colostrum and transition milk of Brown Swiss cows
Dokumenttyp:: Konferenzbeitrag
Art des Konferenzbeitrags:: Vortrag / Präsentation
Autor(en):: Ostendorf C.S., Vorndran A.M., Meyer A., Steinhoff-Wagner J.
Seitenangaben Beitrag:: 107
Abstract:: Introduction: The energy content of milk is not only important to calculate lactation requirements of cows, but also for adequate provision of calves with liquid feed. Usually, the energy content of milk is estimated using a variety of formulas. One formula often used for estimation is established by NRC (2001): Gross energy (Mcal/kg) = (Fat% × 0.092) + (Protein% × 0.055) + (Lactose% × 0.039). This formula uses standard heat of combustion for the different energy sources in milk to estimate the gross energy of the sample. However, this formula was adjusted by NASEM (2022) with slightly different heat of combustion for the milk components: Gross energy (Mcal/kg) = (Fat% × 0.094) + (Protein% × 0.056) + (Lactose% × 0.04). Transition milk and especially colostrum vary in their composition of these components compared to mature whole milk. Therefore, using the assumption stated for mature milk could lead to an over- or underestimation of energy content in milk during the first week of lactation. Methods: Milk previously collected and analyzed in Vorndran et al. (2025), consisting of 16 cows (9 multiparous, 7 primiparous) during the first 7 days after parturition, was used for this study. Dry matter was analyzed in a VWR DRY-Line oven according to method C.35.3 Band IV (VDLUFA, 2020). Protein was calculated by multiplication of the analyzed nitrogen concentrations from the Kjeldahl method (VDLUFA, 2020), with the milk protein specific conversion factor 6.38. Fat was analyzed in a Gerhardt Soxtherm apparatus according to the method of Weibull Stoldt (VDLUFA, 2020). Lactose concentration was determined by photometric detection at 340 nm using a certified enzymatic assay. Gross energy of the samples was then calculated using the formula of NASEM (2022) and NRC (2001). Gross energy measurement of milk samples was conducted using small stamped out proportions of freeze dried milk. This was necessary since the fat concentration in milk did not allow for the pressing of small tablets which are used in standard bomb calorimetric measurements. The stamps were weighed in combustible bags with known energy content and measured in a IKA C2000 basic bomb calorimeter. The data was analyzed using JASP Version 0.95.3 (Amsterdam, Netherlands) and checked for normality and homogeneity of variance before analysis. The association between the measured and calculated energy contents was determined by Pearson’s correlation. Significance was set at p <0.05. Results: Measurement results and estimates of energy concentration using the calculations were highly correlated at all time-points (r > 0.5). The NASEM (2022) estimation was closer to the results of bomb calorimetry than the NRC (2001) formula, especially at milkings 1 and 2. While the values of the NRC (2001) estimation numerically tended to underestimate the energy, the NASEM (2022) estimation tended to numerically overestimate energy contents. On average, the results between measurement and estimation differ by only 0.08 MJ/kg DM with the NASEM (2022) formula, but differences of up to 6.012 MJ can be seen in individual samples. Conclusions: The used method of stamping out a portion of the freeze dried sample worked well compared to the calculated estimates from the equations. Both estimations can be used to estimate energy levels with similar accuracy to that measured for transition milk (> day 2) and mature milk of Brown Swiss cows. However, while the average accuracy is good, there are relatively large differences between estimates and measurements in individual samples. Analyzing energy content of colostrum and early transition milk (day 1), only the NASEM (2022) estimation or measuring with a bomb calorimeter seem to be suitable to determine energy content.
Kongress- / Buchtitel:: Proceedings of the Society of Nutrition Physiology 80th Conference 03rd– 06th March 2026 in Göttingen
Band / Teilband / Volume:: 35
Ausrichter der Konferenz:: Society of Nutrition Physiology
Jahr:: 2026
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mediaTUM Gesamtbestand Hochschulbibliographie 2026 Schools TUM School of Life Sciences Professur für Tierernährung und Metabolismus (Prof. Steinhoff-Wagner)

mediaTUM Gesamtbestand Einrichtungen Schools TUM School of Life Sciences Departments Molecular Life Sciences Professur für Tierernährung und Metabolismus (Prof. Steinhoff-Wagner)