Jeroch


Die Bodenkultur - Journal for Land Management, Food and Environment

H. Jeroch, S. Dänicke, J. G. Brettschneider and W. Schumann:

Use of treated rapeseed in brown laying hens

Summary

Two experiments were conducted with laying hens of the origin LOHMANN BROWN to investigate the effects of feeding of untreated and hydrothermal treated rapeseed at dietary inclusion rates of O, 7.5 %, 15 %, 22.5 % or 30 %. Analytical (e, g. glucosinolates, sinapine, trimethylarnine), performance (feed intake, laying intensity; egg weight, egg mass, feed conversion ratio, live weight change) and egg quality parameters were included in the measurements. The results can be summarised as follows:

• Sinapine and glucosinolates of rapeseed were reduced by hydrothermal treatment from 6152 mg per kg (untreated) to less than < 50 mg per kg rapeseed and from 13.8 mmol per kg (untreated) to 1.4 mmol per kg rapeseed, respectively.

• High percentages of both untreated and hydrothermal treated rapeseed in layer diets (22.5 % and 30 %, respectively) resulted in significant reduction in laying intensity and feed conversion ratio. Egg weight remained unchanged for all dietary treatments. Negative effects on live weight change were observed as the dose of rapeseed in the diets was increased. This effect was more pronounced in hens fed untreated rapeseed containing diets.

• A marked reduction in trimethylamine contents of egg yolks was achieved by hydrothermal treatment of rapeseed.

Trimethylamine contents of egg yolks increased as the dietary rapeseed inclusion rate was increased and tended to be higher as the hens aged. However, these effects were much less pronounced in hens fed treated rapeseed variants.

Key words: rapeseed, feed processing, laying hens, laying performance, trimethylamine content of eggs.