Organic dairy production based on rapeseed, rapeseed cake or cereals as supplement to silage ad libitum

Abstract

This experiment presents the effect of 100% organic feed rations grown at an equal area per cow on milk production performance and metabolic responses. A total of 174 Danish Holstein cows were included in two experiments on two commercial organic dairy farms during the winter 2000/2001. Three types of supplementary feed were examined: 5 kg cereals, 3 kg rapeseed/cereal pellet or 1 kg rapeseed cake fed with a mixture of clover grass silage, whole crop silage and grass pellets ad libitum. The supplement of rapeseed/cereal pellet compared with cereals tended to decrease both milk fat and protein content, whereas fat and protein yield were unaffected. Milk yield was increased by supplement of rapeseed/cereal pellet compared with cereals in experiment 1, but unaffected in experiment 2. Consequently, energy corrected milk yield tended to be increased in experiment 1 but decreased in experiment 2. The supplement of rapeseed cake compared with cereals changed neither milk composition nor yield. The risk of subclinical ketosis based on metabolic parameters and other metabolic disorders was not affected by the different feedings.

Keywords:

• β-hydroxybutyrate
• dairy cow
• fatty acids
• glucose
• metabolic responses
• milk production
• NEFA
• organic farm
• roughage

Acknowledgments

Financial support for this research was provided by the Danish Ministry of Food, Agriculture and Fisheries through the programme ‘Research in organic farming 2000–2005’ (DARCOF II). The authors express their thanks to the farmers Erik Andersen and Bent Nielsen for hosting the experiments, the research assistants Gunnar Grønning and Helge Yde and the farm advisers Anders Møller and Knud Møller, for the on-farm registration. We also wish to thank for the skilful help during sampling and analysis of samples given by the laboratory technicians D. Agnholt and Jens B. Clausen.

Notes

Mogensen, L., Ingvartsen, K. L., Kristensen, T., Seested, S., Thamsborg, S. M. (Danish Institute of Agricultural Sciences, Research Centre Foulum, P.O. Box 50, DK-8830 Tjele, Denmark, and Royal Veterinary and Agricultural University, 1870 Frederiksberg C, Denmark). Organic dairy production based on rapeseed, rapeseed cake or cereals as supplement to silage ad libitum.

Additional information

Notes on contributors

Lisbeth Mogensen

Mogensen, L., Ingvartsen, K. L., Kristensen, T., Seested, S., Thamsborg, S. M. (Danish Institute of Agricultural Sciences, Research Centre Foulum, P.O. Box 50, DK-8830 Tjele, Denmark, and Royal Veterinary and Agricultural University, 1870 Frederiksberg C, Denmark). Organic dairy production based on rapeseed, rapeseed cake or cereals as supplement to silage ad libitum.