Getting The Most From Your Silage
Aidan Cushnahan, Dairying Development Adviser, College of Agriculture, Food and Rural Enterprise, Greenmount Campus
The upcoming winter will provide dairy farmers with a number of feeding challenges due to rising concentrate prices and variable silage quality. Now is the time to prepare an effective feeding programme to ensure you get the most from your silage. Analysing stocks and quality of available forages is essential to enable proper ration formulation and budgeting.
Analysing forage quality
It is essential that representative samples of available forages to be fed are taken and analysed in terms of nutritive value. An initial review of silage samples already analysed this autumn would indicate that there are major variations in terms of dry matter (DM) and metabolisable energy (ME) content. This variation could have a major impact on energy intakes by dairy cows and subsequent milk production, milk quality, herd health and fertility. Accurate forage analysis enables the right rations to be fed at the right levels for optimum performance.
It is essential that representative samples of available forages to be fed are taken and analysed in terms of nutritive value. An initial review of silage samples already analysed this autumn would indicate that there are major variations in terms of dry matter (DM) and metabolisable energy (ME) content. This variation could have a major impact on energy intakes by dairy cows and subsequent milk production, milk quality, herd health and fertility. Accurate forage analysis enables the right rations to be fed at the right levels for optimum performance.
Assessing silage stocks
A number of farmers may already be in a situation where silage stocks are lower than normal after prolonged periods of buffer feeding last summer. Now is the time to assess levels of available forage and plan accordingly. Stocks of silage can be determined by calculating the volume of material in the silo (length x breadth x depth (m)) and by using the conversion factors given in Table 1.
A number of farmers may already be in a situation where silage stocks are lower than normal after prolonged periods of buffer feeding last summer. Now is the time to assess levels of available forage and plan accordingly. Stocks of silage can be determined by calculating the volume of material in the silo (length x breadth x depth (m)) and by using the conversion factors given in Table 1.
Table 1. Conversion factors to convert silage volume to tonnes of silage
| Silage DM content (percent) | Conversion factor (m3 to tonnes) |
|---|---|
|
18
|
Multiply by 0.81
|
|
20
|
Multiply by 0.77
|
|
22
|
Multiply by 0.73
|
|
25
|
Multiply by 0.68
|
|
30
|
Multiply by 0.60
|
Typical monthly feed requirements for various classes of livestock given in Table 2
Table 2. Monthly feed requirements for different classes of livestock
| Livestock | Silage (tonnes/month) |
|---|---|
| Dairy cow (milking) |
1.5
|
| Dairy cow (dry) |
1.0
|
| Animals (>350kg) |
1.0
|
|
Animals (250-350kg)
|
0.8
|
| Animals (200-250kg) |
0.7
|
| Calves |
0.3
|
Planning an effective feed programme
Farmers aiming to get optimal performance from moderate/ poor quality silages, and/ or limited supplies of forage should consider the following points:
Farmers aiming to get optimal performance from moderate/ poor quality silages, and/ or limited supplies of forage should consider the following points:
- Aim to calve cows down at condition score 2.5 – 3.0
- Target the best quality forage towards early lactation cows and higher yielding animals
- Ruminants require at least 25 percent of the diet as long fibre. Target restricted forage diets towards late lactation cows, dry cows and youngstock.
- Ensure that all animals have access to fresh, clean forage on a regular basis.
- When silage is of moderate/ poor quality then increased levels of supplementary feeding will be required. Typical levels of feeding for a range of yields are given in Table 3. Discuss the most appropriate level of feeding for your herd with your local Dairying Development Adviser or feed specialist.
- Increased levels of concentrate feeding (more than 9kg/ cow/ day) will necessitate the use of mid day feeds or alternative feeding methods outside the milking parlour
- Use concentrates based on digestible fibre sources (sugar beet pulp, citrus pulp, soya hulls) to promote forage intakes and reduce the risk of digestive upsets
- Using straw or alternative forages will reduce silage requirements. However the relative value of these feeds should be considered before making any decisions
Consider using extended grazing techniques in late autumn/ early spring to prolong stocks of silage
Table 3. Suggested levels of feeding to maintain given milk yields over a range of silages
| Cow performance | Silage feed value | |||
|---|---|---|---|---|
|
Target milk yield
|
Peak yield (l/day)
|
Good
|
Average
|
Poor
|
|
5,500
|
27.5
|
6.0
|
8.0
|
10.0
|
|
6,500
|
32.5
|
8.0
|
10.0
|
12.0
|
|
7,500
|
37.5
|
10.0
|
12.0
|
14.0
|
|
8,500
|
42.5
|
12.0
|
14.0
|
16.0
|
Monitoring herd performance
It is important that herd performance is monitored throughout the winter. Feed intakes, milk yield and composition, and body condition scores are key indicators of herd performance and should be checked on a regular basis to ensure that performance targets are being met and the feed plan is working.
It is important that herd performance is monitored throughout the winter. Feed intakes, milk yield and composition, and body condition scores are key indicators of herd performance and should be checked on a regular basis to ensure that performance targets are being met and the feed plan is working.
Summary
Farmers aiming to get the most from their silages this winter should analyse their forages now and plan accordingly. Your local Dairying Development Adviser is available to help you develop the skills required to produce an effective feeding programme. Additional information on winter feeding is also available on the rural portal (www.ruralni.gov.uk)
Farmers aiming to get the most from their silages this winter should analyse their forages now and plan accordingly. Your local Dairying Development Adviser is available to help you develop the skills required to produce an effective feeding programme. Additional information on winter feeding is also available on the rural portal (www.ruralni.gov.uk)
Aidan Cushnahan and Richard Woolsey, Toomebridge discuss silage analysis results