Project code: D-20-04
Duration 12 months from January 2004
Team and Leader D.C. Patterson
Organisations Involved Agricultural Research Institute of Northern Ireland and Department of Agriculture and Rural Development for Northern Ireland
Background and Summary
There is currently an increasing interest in the production of alternative forage crops for feeding to high yielding dairy cows. This reflects both the potentially lower production costs per unit of energy associated with some alternative forage crops and the ability of some of these crops to increase total dry matter intake and improve milk yield. High starch forage maize is becoming established as a forage to increase forage intake, milk yield and the protein contant of milk.
It is therefore proposed to include high starch forgae maize as one of the alternative forages. Earlier studies have shown that fermented whole crop wheat increased forage intake but generally had no beneficial effect on the performance of lactating dairy cattle. However, the new technique of milling or cracking the grain during harvesting as whole crop has enabled whole crop wheat to be ensiled at high dry matter contants (70 to 80% DM).
These crops are treated with a urea plus urease product (Alkalage Home and Dry) to generate ammonia to preserve the crop. A further treatment harvested at 40% dry matter (fermented whole crop) will be included as preliminary results from this type of crop suggest a small milk production response (last winter`s experiment at ARINI). Both the forage maize and whole crop wheat forages will be included at 40% of total forage dry matter with grass silage comprising the remainder of the forage.
An important feature of the proposed study is that two qualities of grass silage will be used to complement the alternative forages with target D-values of 65 and 75 to represent a two cut system or a high quality 3 cut approach respectively. Additionally, four control treatments will be comprised of the two qualities of grass silage as the sole forage x two levels of concentrate supplementation. The overall arrangement of treatments will permit determination of both the concentrate sparing effects of the alternative forages and the grass silage quality equivalence values of the alternative forages, including high dry matter whole crop wheat.
The objectives of the proposed study are:
1. To measure dry cow responses to alternative forages including high dry matter whole crop wheat
2. To determine the grass silage equivalence values of a range of alternative forages
3. To determine the concentrate sparing effects of a range of alternative forages
The study will involve a total of 40 freshly calves dairy cows with 10 treatments applied for a total of 10 weeks in a 2 period changeover design with:
1. Grass silage + 7 kg concentrates/day
2. Grass silage + 10 kg concentrates/day
3. High starch maize silage* plus 7 kg concentrates/day
4. Fermented whole crop wheat - approximately 40% DM* plus 7 kg concentrates/day
5. High DM whole crop wheat treated with urea plus urease - 70 - 80% DM* plus 7 kg concentrates/day
* Alternative forages at 40% of total forage DMI
Measurement will include forage intake, milk yield, milk composition, liveweight change and body condition score.
AgriSearch awaiting final report.
1. Provide unbiased information to the industry on measured responses (or lack of response) to a range of alternative forages under Northern Ireland conditions.
2. To keep up with newer technologies applied to high dry matter whole crop wheat.