Cotswold Seeds Ltd. Extending the Grazing Season

Grain Maize for Better Silage?

Over the last two decades plant breeders have moved the boundary for growing forage maize in Europe further north by developing earlier varieties. The same is true of grain maize (where the focus of yield is on the cob). Last year, in Holland, the area expanded by 30 per cent to 26,000 Ha a situation, which would have been difficult to predict 10 years ago.

This recent expansion has been boosted by the introduction of a new variety called Ohio (Table 1). In recommended list trials it produced 10 per cent more maize than the main early grain variety Husar. This breeding is an advantage to the UK because it not only means there is a possibility of grain maize production in the south east, but more importantly, availability of early grain varieties for producing higher starch maize for livestock farmers.

Table 1. Dutch Official Trials 2000
	Ohio	Husar
Relative grain yield	104	94
Relative DM content of grain	105	104
Earliness of flowering	8.5	8.5
Earliness of grain ripening	8.5	9

The best grain varieties will be vigorous, early flowering and have early cob development. The hybrids have the added benefit of excellent resistance to lodging and brackling, which is needed to ensure safe harvest by combine. This is an advantage in the UK where there is a risk of autumnal storms arriving before the contractor.

Grain varieties normally don’t yield as much silage as forage types but their higher starch content produces excellent digestibility levels that are often much higher than forage varieties. This can be noted in the UK descriptive list where grain varieties Manatan, Speedy and Loft exhibit excellent starch percentage and ME but lack optimum yield. Their potential energy yield is on a par with some of the higher yielding forage types.

In Holland, quality is considered to be as important as yield, with the key factor in evaluating maize being digestible yield (VEM). A measurement which if adopted would strengthen the UK descriptive list by closely identifying the income potential of a variety. In general, farmers feeding very high levels of maize silage select varieties with high VEM, but not necessarily the highest starch percentage. This is because of the inability of the cow to utilise very high levels of starch in their diet. It is when buffer feeding cows at grass or when feeding lower percentage maize diets (-60 per cent), the starch content can come into its own. High starch maize complements the grass based ration.

The Dutch Co-op, Cebeco tested Ohio for its performance as silage maize against the leading forage varieties. In some areas results were surprising (Table 2).

As Table 2 shows, Ohio produced yields similar to the major forage varieties. It produced exceptional starch content and excellent digestibility, proving Ohio to be a true dual-purpose variety.

In Holland, the best grain varieties can potentially compete with silage hybrids for yield, but results in the UK may be different. In 2000 and 2001, the breeder, KWS, tested Ohio at five UK sites. Table 3 compares it to some of the best varieties available. Results confirm the hybrid’s adaptability to UK conditions.

There is limited availability of Ohio this year though extra seed production is planned for 2003. In the mean time, if farmers are feeding less than 60 per cent of their winter ration or buffer feeding at grass in the summer, they might consider trying some high grain Manatan, Speedy or Loft.

Table 2. AGRIFERM – CEBECO Trials 2001
	DM%	Relative DM Yield	Digestibility (VEM)	Relative Digestible Yield	Starch Content	Relative Starch Yield
OHIO	33.8	104	100	102	44.2	116
Crescendo	31.5	97	101	91	41.8	97
Goldoli	31.5	97	99	96	38.1	96
Cameron	32.7	101	99	104	38.5	104

Table 3. KWS Results 2000 – Mean of five sites
Ranking By	Starch Yield T/Ha	Ranking By	Digestible DM Yield T/Ha
OHIO	7.07	JUSTINA	14.25
JUSTINA	6.77	OHIO	13.99
CRESCENDO	6.66	VERNAL	13.59
VERNAL	6.33	CRESCENDO	13.47
MELODY	6.29	MELODY	13.30
FABIUS	5.38	FABIUS	11.85

Forage Matters Spring 2001

- Francis Dunne of Cebeco prepared this article for Forage Matters.

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Grain Maize for Better Silage?