Nutrient composition, ruminal degradability and whole tract digestibility of whole crop maize silage from nine current varieties

ABSTRACT

Since maize silage is an important forage in cattle nutrition, it is important to know its nutritive value. Much effort is put into breeding maize, and several new varieties are introduced on the market every year. This requires periodical analyses of the nutritive value of current maize varieties for the formulation of cattle rations. The aim of this study was to examine the nutritive value of whole crop maize silage (WCMS) from nine maize varieties in 3 consecutive years. For the analysis of nutrient composition and ruminal degradability of organic matter (OM), crude protein (CP), neutral detergent fibre (aNDFom) and non-fibre carbohydrates (NFC), varieties were harvested at three harvest dates (50%, 55% and 60% dry matter content in ear). Due to capacity limitations, the digestibility of WCMS was tested only for the middle harvest date. The CP and acid detergent fibre (ADFom) content was affected (p < 0.05) while aNDFom and NFC content was not influenced by variety. With advancing maturity, CP, aNDFom and ADFom content declined while NFC content increased. Variety influenced effective ruminal degradability (ED) of nutrients, except for CP. The ED of all examined nutrients decreased as maturity advanced from first to third harvest date. Digestibility of OM, ADFom and NFC was significantly and digestibility of aNDFom was tendentially (p = 0.064) influenced by variety. Additionally, an effect of year and a harvest date × year interaction was found for almost all examined parameters. In conclusion, variety, harvest date and year influence the nutritive value of WCMS. A comparison with earlier studies shows that current varieties have a higher fibre digestibility and a slower-ripening stover compared to older varieties.

KEYWORDS:

• Harvesting date
• maize
• nutritive value
• varieties
• whole crop silage
• year

Acknowledgements

This project was carried out with technical and material support of Franz Kastenhuber as well as the experts from the Austrian Chamber for Agriculture and the Austrian Agency for Health and Food Safety. Weather data was provided by the Central Institute for Meteorology and Geodynamics (ZAMG). Kathleen Knaus provided English language editing. We would like to thank all supporters for their contributions to this project.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The investigations were funded by the Austrian Ministry of Agriculture, Forestry, Environment and Water Management.