Many farmers know the feed value of the ration they use daily, but have no knowledge of the feed value of their silage. Across Northern Ireland, grass silage dominates cattle diets throughout winter. Today, as you enter your silage clamp to begin the daily routine of feeding cattle, ask yourself a few questions:
Do you know the value of what they are feeding in terms of energy and protein?Do you know what it cost to produce a tonne of silage this year?How many tonnes of silage have you sitting in reserve this year? Is silage quality better or worse than last year and how do you know?Are cattle performing on silage and what is their daily gain?Simply lifting a handful of silage and smelling it will tell you nothing about the feed value of the forage or how many kilogrammes of weight gain it will sustain. Squeezing silage to see how much moisture is present will merely indicate how dry the feed is.
The programme farmers routinely test silage so that they can formulate winter feeding rations accordingly. There is serious financial savings to be made if feed value allows the farmers to reduce concentrate feeding.
And vice versa, there are occasions when silage analysis indicated a lower than expected feed value and a higher rate of meal feeding was required.
Silage analysis
Tables 1 and 2 outline the silage analysis for first and second cuts on the 10 programme farms in 2016. On seven of the farms, silage was harvested in May, with the remainder harvested in June.
Protein levels are excellent, with nine farmers having forage analysis indicating protein levels above 12%. While protein was lower for first-cut silage on John Egerton’s farm, the analysis shows a high energy value and a high D-Value of 71.
A high D value is important as it indicates higher levels of digestibility, especially for energy and protein as the overall feed value is important, not just one single component.
Higher digestibility means there is greater nutrient availability. Ideally, the farms are targeting silage with a D value of 70 or better.
Energy levels are mixed on farm, with very high results on James Taylor’s farm, as well as John Dobson, John Egerton and Andrew Gardiner’s farms. Higher energy levels allow for savings to be made by reducing concentrate levels in finishing diets.
Depending on the digestibility of the grass, it will also improve cow body condition, which is particularly important for the farmers operating autumn-calving herds. Getting more energy into the autumn cow after calving helps to drive milk production and bring cows back into heat quicker.
Priority feeding
Along with finishing cattle and autumn-calving cows, good silage is being targeted to weanlings to maximise weight gain over the winter period. Target growth rates are around 0.6kg/day.
Weanlings were front-loaded with 2kg to 3kg/day of meal to ensure they have a smoother transition from grazing to housing. These weanlings will then be weighed in early January and meal rates will be reduced in most cases if weight gains are on target for turnout in spring.
Heifers that will be bred next summer at 15 months are a high-priority group on all farms, as the weight of the animal next May will have a massive influence on fertility. Heifers that are better developed and weigh in excess of 400kg liveweight have a much better chance of going in-calf and being able to cope with calving at 24 months. It also increases the chance of getting these heifers to go back in-calf again.
Second-cut silage
Most of the programme farmers have average-quality second-cut silage. Second-cut silage can provide adequate feeding for dry suckler cows over the winter, provided they are in ideal body condition.
Where silage has a D value of 66 or lower, this forage should not be targeted to finishing cattle or autumn-calving cows that are in early lactation or during their breeding period.
If good-quality silage supplies are tight and average-quality silage has to be fed, cattle should move gradually on to average silage and concentrate levels should be adjusted to account for the reduced feed value.
Factors analysed
1. Dry matter – this relates to how much water is present in the feed. The higher the value, the drier the silage. Ideally, silage should be around 25% to 30% DM for pit silage, and 30% to 35% for baled silage.
2. Protein – high-quality grass silage should have protein levels of 12% to 14%, while headed-out grass will have levels of 9-10%. With higher protein levels, performance will be improved and concentrate use can be reduced.
3. Energy – similar to protein, high-quality grass silage will have energy values around 11.0 to 12 Mj ME/kg DM.
4. D value – this is an overall evaluation of the forage and the higher D value, the less concentrate is required in the diet.
5. pH – this indicates how well preserved the forage is and should have a value between 3.8 and 4.2. Wet silage can have a high pH, which causes the feed to spoil quickly.
Click on the image for full-size table
Many farmers know the feed value of the ration they use daily, but have no knowledge of the feed value of their silage. Across Northern Ireland, grass silage dominates cattle diets throughout winter. Today, as you enter your silage clamp to begin the daily routine of feeding cattle, ask yourself a few questions:
Do you know the value of what they are feeding in terms of energy and protein?Do you know what it cost to produce a tonne of silage this year?How many tonnes of silage have you sitting in reserve this year? Is silage quality better or worse than last year and how do you know?Are cattle performing on silage and what is their daily gain?Simply lifting a handful of silage and smelling it will tell you nothing about the feed value of the forage or how many kilogrammes of weight gain it will sustain. Squeezing silage to see how much moisture is present will merely indicate how dry the feed is.
The programme farmers routinely test silage so that they can formulate winter feeding rations accordingly. There is serious financial savings to be made if feed value allows the farmers to reduce concentrate feeding.
And vice versa, there are occasions when silage analysis indicated a lower than expected feed value and a higher rate of meal feeding was required.
Silage analysis
Tables 1 and 2 outline the silage analysis for first and second cuts on the 10 programme farms in 2016. On seven of the farms, silage was harvested in May, with the remainder harvested in June.
Protein levels are excellent, with nine farmers having forage analysis indicating protein levels above 12%. While protein was lower for first-cut silage on John Egerton’s farm, the analysis shows a high energy value and a high D-Value of 71.
A high D value is important as it indicates higher levels of digestibility, especially for energy and protein as the overall feed value is important, not just one single component.
Higher digestibility means there is greater nutrient availability. Ideally, the farms are targeting silage with a D value of 70 or better.
Energy levels are mixed on farm, with very high results on James Taylor’s farm, as well as John Dobson, John Egerton and Andrew Gardiner’s farms. Higher energy levels allow for savings to be made by reducing concentrate levels in finishing diets.
Depending on the digestibility of the grass, it will also improve cow body condition, which is particularly important for the farmers operating autumn-calving herds. Getting more energy into the autumn cow after calving helps to drive milk production and bring cows back into heat quicker.
Priority feeding
Along with finishing cattle and autumn-calving cows, good silage is being targeted to weanlings to maximise weight gain over the winter period. Target growth rates are around 0.6kg/day.
Weanlings were front-loaded with 2kg to 3kg/day of meal to ensure they have a smoother transition from grazing to housing. These weanlings will then be weighed in early January and meal rates will be reduced in most cases if weight gains are on target for turnout in spring.
Heifers that will be bred next summer at 15 months are a high-priority group on all farms, as the weight of the animal next May will have a massive influence on fertility. Heifers that are better developed and weigh in excess of 400kg liveweight have a much better chance of going in-calf and being able to cope with calving at 24 months. It also increases the chance of getting these heifers to go back in-calf again.
Second-cut silage
Most of the programme farmers have average-quality second-cut silage. Second-cut silage can provide adequate feeding for dry suckler cows over the winter, provided they are in ideal body condition.
Where silage has a D value of 66 or lower, this forage should not be targeted to finishing cattle or autumn-calving cows that are in early lactation or during their breeding period.
If good-quality silage supplies are tight and average-quality silage has to be fed, cattle should move gradually on to average silage and concentrate levels should be adjusted to account for the reduced feed value.
Factors analysed
1. Dry matter – this relates to how much water is present in the feed. The higher the value, the drier the silage. Ideally, silage should be around 25% to 30% DM for pit silage, and 30% to 35% for baled silage.
2. Protein – high-quality grass silage should have protein levels of 12% to 14%, while headed-out grass will have levels of 9-10%. With higher protein levels, performance will be improved and concentrate use can be reduced.
3. Energy – similar to protein, high-quality grass silage will have energy values around 11.0 to 12 Mj ME/kg DM.
4. D value – this is an overall evaluation of the forage and the higher D value, the less concentrate is required in the diet.
5. pH – this indicates how well preserved the forage is and should have a value between 3.8 and 4.2. Wet silage can have a high pH, which causes the feed to spoil quickly.
Click on the image for full-size table
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