Feeding options for the drought and winter

The current drought has seen grass growth rates plummet. Every farm in the country is affected in some way or another but some are worse than others. Where growth rates and grass covers remain good, that is in excess of 140kgDM/cow and growth rates at or above herd demand, then farmers should go on a rotation length of 20 to 25 days and supplement with meal, if necessary.

But most farmers are experiencing lower growth rates and lower average farm covers. In these circumstances, grass and meal are not enough to keep cows fed. The big issue is that cows are ruminants, and unlike pigs or poultry, they need at least 50% roughage in their diet. This roughage is normally provided by grass, but where grass is gone, it needs to be replaced by either hay or silage.

So, if a typical cow eats 18kg of dry matter per day, about 9kg of dry matter should be in the form of roughage, either grass, silage or hay. The rest of the diet can be made up of concentrates. The timing of this drought couldn’t be worse from a farmer’s perspective as it comes on the back of a long winter that saw silage stocks depleted. So feeding silage now is counterproductive to the objective of building up silage stocks for next winter. It is for this reason that farmers are so worried about having to feed silage now.

But the game is not over yet. When the rain does come, grass growth will increase and a lot of the lost growth will be made back with higher than normal growth rates. In the unlikely event that the drought persists into late autumn and not enough winter feed is made, silage can be supplemented in winter too. So don’t resist feeding silage to milking cows now, if that is what they need.

In terms of diets, getting as much grass into cows for as long as possible is ideal. But with many grass swards now wilting away in the heat and drought, going on a long rotation length is not very beneficial. It depends on the situation on the farm.

Where some grass is available, increasing the amount of concentrate feed to 6kg and feeding 6kg of silage either by day or by night and then grass in the other grazing is a good option. The diet will be well balanced for energy and protein. Where silage and grass quality is poor, extra meal could be fed.

Where not enough grass is available to feed 6kg/cow/day, then more silage or more meal or more of both will have to be fed. Feeding any more than 6kg or 7kg of meal will require more than two feeds though. Feeding 3kg of meal in the parlour at milking time is about the most that is practical. If more concentrate is to be fed, it will need to be fed outside of milking times. To facilitate this, farmers feeding high levels of meal are bringing cows into the yard where there is soya hulls or palm kernel available. Other farmers are feeding palm kernel in troughs in the field.

Palm kernel is now in limited supply and unavailable in some areas, so unless farmers have supplies in their yard, it is not likely to be part of the feed solution. Soya hulls are more readily available but intakes of soya hulls will have to be monitored, as cows could gorge on it if they are not restricted. This means it must be fed out to cows in the required quantities and not fed ad lib. Soya hulls and palm kernel are high-fibre feeds.

Other straights might have higher energy and protein values, but have low fibre levels. Fibre is important when forage levels are low.

Many farmers have decided to graze or zero-graze grass intended for second cut silage. I think this is the right decision. It makes more sense to graze this as a standing crop than to go through the costs of harvesting and ensiling it. Of course, the reasons farmers are slow to graze silage is the fear of not having enough silage for the winter.

Where to feed silage or zero-grazed grass is the next question. Most farmers will continue to have grazed grass in the diet over the next few weeks. Feeding the extra silage or cut grass in the paddock will suit some farmers. It can reduce the workload by not having to bring cows into a yard or shed for feeding.

Feeding methods will vary depending on numbers but in the Greenfield farm round bales are left in the paddock where the cows are grazing and a strip wire is put up around them with the cows eating under the wire.

Other farmers are doing the same with zero-grazed grass.

They normally move the strip wire closer to the bales at least once during the day and utilisation is good. If cows are going into shed for silage, the cubicle area should be closed off, but where this is not possible cubicles will need to be cleaned and disinfected with lime. In these temperatures, the risk of mastitis is high.

Other farmers are picking a paddock near the yard and feeding silage there. This also works well but like cubicle sheds, if the cows no longer have a clean lie area, the risk of mastitis elevates. Another issue with just using one field for silage is that the risk of nutrient loading rises the longer that field is used. This will sour the subsequent grass.

Sufficient silage

At a drought farm walk on the farm of Larry Kearney in Rathcormac, Co Cork, last week, Teagasc area manager Billy Kelleher said that while not having enough silage is a concern, you only need to have 50% of the silage that you need for the winter.

“Because half of the diet needs to be roughage or silage, the rest of the diet can be made up of meals, straights, hay, straw or whatever else is available. The key thing is not to have less than 50% of the silage or roughage that you need and to know this you must do a fodder budget now,” Billy said.

After establishing that fodder will be short for the winter, the options then include purchasing:

Of course, all of these feeds are in scarce supply and what is available is very expensive because demand is very strong. Other feed options include sowing forage crops such as rape or redstart on outside blocks. If sown in late July or early August they can have a yield potential of between 6t DM/ha and 8t DM/ha. Cows and youngstock can be outwintered on redstart but some form of roughage such as bale silage should be fed with it.

Of course it’s not just about providing feed. Demand for feed can also be reduced. Cows can be scanned early and sold in August. Problem cows such as those with a high somatic cell count or those that are lame or poor milkers should be sold to reduce demand. If extra youngstock or beef cattle are on hand, ask yourself if they are needed. Demand can also be reduced by putting stock on bed and breakfast over the winter.