First cut in grass­land: Silage man­age­ment and feed quality

The first cut in grass­land is immi­nent. After sev­er­al dry years, the feed reserves of many dairy farms have dimin­ished. This makes it all the more impor­tant that this first cut results in good feed efficiency.

Just as in every har­vest process in crop cul­ti­va­tion green crop har­vest comes down to a bal­ance includ­ing yield, qual­i­ty and cost. Har­vest, and the relat­ed silage, forms the basis for opti­mal feed in dairy farm­ing. When it comes to cat­tle feed, half of the main stock for­mer should be at the ear or pan­i­cle emer­gence stage for high-per­for­mance silages. The TM con­tent should be between 21–23 %. Falling below this val­ue can have just as neg­a­tive an impact on silage qual­i­ty as exceed­ing the TM content.

In addi­tion, the weath­er has a major impact on green crop. The trade-off here is to har­vest a lit­tle ear­li­er and not obtain the max­i­mum yield, or har­vest the first cut in the grass­land at a lat­er date but risk a loss of qual­i­ty. The selec­tion of silage addi­tive is made based on the weath­er con­di­tions. For exam­ple, in per­sis­tent cool weath­er and low sun­light, few lac­tic acid bac­te­ria are present on the crop dur­ing mow­ing. To ensure nutri­ent-rich and digestible silage and avoid reheat­ing, it would be advis­able to add lac­tic acid bacteria.

Increase feed qual­i­ty with the first cut in grassland 

Nutri­ent man­age­ment has already been men­tioned as a lever for ensur­ing yield and qual­i­ty with the first cut in grass­land. The tim­ing and the quan­ti­ties and types of nitro­gen and sul­phur admin­is­tered are espe­cial­ly cru­cial here. On-farm manure should be sup­ple­ment­ed with a min­er­al fer­tilis­er appli­ca­tion, since it is slow act­ing. Stud­ies have shown that a well-found­ed manure strat­e­gy could dou­ble the grass­land harvest.

It is impor­tant to make an ini­tial appli­ca­tion in the spring, when nutri­ent reserves from the soil are poor­ly avail­able, but for­age grass­es need to build up a high lev­el of plant mass in a short time. A min­er­al fer­tilis­er con­tain­ing nitrates and sul­phates sup­plies quick­ly-avail­able nutri­ents to the roots. The choice of nitro­gen type here is deci­sive: Ammo­ni­um nitrate acts quick­ly and with­out ammo­nia loss­es through out­gassing. Urea, on the oth­er hand, is espe­cial­ly dis­ad­van­ta­geous dur­ing dry years, when ammo­nia loss­es are increased. In turn, sul­phur helps the grass­es to use the nitro­gen offered, as it ensures high­er yields and increas­es the raw pro­tein con­tent of the silage.

Sev­er­al para­me­ters describe the feed qual­i­ty of a grass silage, includ­ing the ener­gy and crude pro­tein con­tent, the struc­tur­al impact, the car­bo­hy­drate con­tent, min­er­al and active ingre­di­ent con­tent, the fer­men­ta­tion qual­i­ty, hygien­ic con­di­tion and the aer­o­bic sta­bil­i­ty of the silage. In order to ensure these para­me­ters and there­fore the suc­cess of the silage in a sta­ble way, the har­vest­ing process must be opti­mal­ly designed in all its steps. Sys­tems for auto­mat­i­cal­ly record­ing agri­cul­tur­al oper­a­tions may assist here, as they ensure the oper­a­tional effec­tive­ness of the machines in the process chain and there­fore improve the cost bal­ance of the basic feed supply.

After the first step, this is a good point at which to reseed patchy stands and close the grass­land sward. This helps to pre­vent sand ingress at the next har­vest and the spread of weeds.

What does good silage man­age­ment need?

Basic, top-qual­i­ty feed can be pro­duced with a sophis­ti­cat­ed and coor­di­nat­ed silage man­age­ment sys­tem. Many fac­tors — from the plant stock already described above, its care, fer­til­i­sa­tion and har­vest date all the way to the tech­ni­cal and logis­ti­cal design of silage prepa­ra­tion — have an impact on the effi­cien­cy of milk pro­duc­tion as a green crop. The fol­low­ing ten points are con­sid­ered impor­tant when it comes to silage management:

• When it comes to grass­land cul­ti­va­tion, drag­ging and rolling, adapt­ed fer­til­i­sa­tion close to the soil and reg­u­lar reseed­ing in both spring and autumn are the most impor­tant oper­a­tions for a healthy, pro­duc­tive crop.
• In the event of any doubt, the opti­mal cut­ting time is ear­li­er rather than lat­er. This also ensures high qual­i­ty dur­ing sub­se­quent cuts.
• The cut height should be at least 8 cm, depend­ing on the main­te­nance con­di­tion, while in the case of rodent infes­ta­tion and for reseed­ings, a greater height should be select­ed. This means that less dirt gets into the silage and new shoots are encouraged.
• The short­est pos­si­ble wilt­ing to a dry mat­ter con­tent of between 30 and 40 % allows opti­mum silage with low losses.
• The field lay time should be under 24 hours. Too much sug­ar is con­sumed dur­ing longer lay times.
• The ide­al length of cut is between 15 and 40 mm. The dri­er and old­er the grass, the short­er the length of cut. Very short cuts should be car­ried out for TMs of over 40 % (or more than 25 % raw fibre content).
• Ensil­ing agents sup­port the fer­men­ta­tion process with dif­fer­ent direc­tions of action. Depend­ing on ensil­ing con­di­tions (con­t­a­m­i­na­tion, over­ly damp or dry crop, cold), the addi­tion of an ensil­ing agent opti­mis­es the fer­men­ta­tion process.
• Good com­paction of the grass silage accel­er­ates the decom­po­si­tion of aer­o­bic organ­isms. In the anaer­o­bic con­di­tions, the pro­lif­er­a­tion of lac­tic acid con­di­tions is favoured, so the pH val­ue can be reduced more quick­ly and the nutri­ent loss­es dur­ing heat­ing are lower.
• Cov­er­ing must take place imme­di­ate­ly after re-rolling has been com­plet­ed. First, the stack is cov­ered with an under­lay film to ensure it is air­tight, after which fol­lows the silo tarp. The stack must also be cov­ered to ensure it is gas-tight dur­ing longer breaks in ensiling.
• Removal should be per­formed with a small cut­ting area and there­fore the least pos­si­ble dam­age, with a min­i­mum feed rate of 2 m per week.