Evaluation of the NEL system and estimation of energy requirements for dairy cows on the basis of an extensive data set from feeding trials.
- Publication Type
- Contribution to conference
- Authors
- Gruber L., Susenbeth A., Schwarz F.J., Fischer B., Spiekers H., Steingaß H., Meyer U., Chassot A., Jilg T. and Obermaier A.
- Year of publication
- 2007
- Published in
- Proc. 16th International Science Symposium on Nutrition of Domestic Animals.
- Band/Volume
- 16/
- Series/labeling
- Zadravec-Erjavec days
- ISBN / ISSN / eISSN
- 978-961-90951-5-7
- Page (from - to)
- 232-237
- Conference location
- Radenci/Slovenia
- Conference date
- 08.11.2007
- Keywords
- dairy cow, energy requirements, feeding
The maintenance requirements of dairy cows are assumed to be about 0.293 – 0.350 MJ NEL/kg LW0.75 in most of the recent energy systems established in Europe and USA. The utilisation of ME for milk production (kl) is in the range of 0.60 – 0.63 in these systems. Recent research results from Northern Ireland indicate both a higher maintenance requirement and a higher energetic efficiency for milk production.A comprehensive data set obtained from long term feeding experiments with lactating dairy cows carried out in 9 research Institutes of Germany, Austria and Switzerland was used to evaluate the current German feeding standards (GfE 2001). The NEL system was validated by regressing the NEL requirements calculated on the basis of its assumptions on the actual NEL intakes (MJ). ME requirements were estimated using multiple regression analysis with LW0.75 (live weight), LE (lactation energy), and LWC (live weight change) as independent variables.The validation of the NEL system is described by the following equation and shows high individual deviations from the regression live, leading to low R2: