As little as 10 kg of maize silage does the trick

I have visited a lot of my autumn calving customers over the last few weeks.

In general, cows are milking well in these herds, apart form where poor silage has been produced, and no second forage is available.

Many had intended to keep their maize silage until January, but had no choice but to open it, because cows were not firing on grass silage-based diets, no matter how much meal was being fed.

As little as 10 kg of maize silage, delivering around 3kg of dry matter, or one seventh of the diet, has been doing the trick. It simply encourages extra dry matter intake from forage, and improves rumen function.

Addition of beet is also a help in this situation; again, it will encourage extra intake, driving total energy intake.

Factors affecting cow performance

The number one ingredient which influences performance in an autumn-calving dairy herd is the forage source.

In almost all cases, that is grass silage, plus or minus maize or whole crop.

It is a reality that there are many issues with grass silages on farms this year.

- First cut grass on many farms this year was harvested later than planned, due to the wet spring and poor growth conditions. As a result, these silages are much lower in quality than would usually be fed to autumn calvers.

Energy values are lower than ideal and, in particular, the proteins in first cuts are lower than normal.

Many delayed their cutting date in order to bulk up their pits and, as a result, the grass had gone stemmy, and the seed head had emerged, which yielded lower than desirable DMD values.

The later the crops were cut, the poor the quality, and the higher the dry matter.

Many first cut crops also have another issue — high ash levels due to clay and/or slurry contamination.

- Early May cut silages are quite good quality, but yields were low due to the poorer spring growth.

- Many of the June-cut grass silages were hit by the drought, and were much drier than normal.

These silages have proved very difficult to manage at feed-out, due to heating and moulds. Many pits are so dry that it is difficult with even the sharpest shear grab to cut a clean face, resulting in a larger surface area exposed, and potential for spoilage.

- Second cuts, as we know, were very low-yielding on sthe farms that managed to harvest them. Many of the crops were grazed rather than cut.

Those that were harvested were scorched in the field before being harvested.

I have tested quite a few second cuts over the last few weeks, and the best description I can give of them is that of toasted grass.

In general, they have tested 60 and lower for DMD, are very high in dry matter with many close to 50%, and have very low energy levels.

Many second cuts will hardly even maintain dry cows. A high proportion of these silages are heating and have moulds present.

- Third cuts taken in September on many farms are the best quality silages in the yard. They are mostly mid 20s for dry matter, and have much higher protein values than first cuts.

- Those that set Westerwolds after winter cereals have at this stage taken two cuts from these crops.

One observation of these silages is that they are lower in dry matter, with many below 20%, while feed quality is excellent, with any of those I have tested being 75% plus for DMD, with 14% plus crude protein. These crops have the potential to produce a lot of feeding next spring.

The mould issue is very significant around the country, and must not be ignored.

- Mycotoxins entering a cow’s diet can have many different negative effects on performance and animal health.

Mycotoxins can and will result in a significant reduction in bug population in a cow’s digestive system.

This will have a detrimental effect on cow performance and her general health.

There are many different signs that mycotoxins are an issue: loose dungs, variable intakes from day to day, swollen joints, stock losing excessive body condition, poor conception and/or poor expression of heat, cows dropping calves well before time, failing for antibiotics in the milk even with no cow in withdrawal, retained foetal membranes. And many more issues have been reported.

Many herds have introduced a mycotoxin binder to diets, to either address an issue they have encountered in their herd, or as an insurance policy to prevent any potential issues.

- Maize silages in general this year are fantastic quality.

Most are exceptionally stable in the pit because they were still green in the field at harvest. As a result, they are below 32% dry matter, which is much easier to manage in the clamp. Starch values in a lmost all maize pits I have tested are well above 30%, with excellent energy values.

I get the impression that the acreage of maize silage in Ireland for 2019 will be well up on recent years.

Many milk producers will realised that it is a very reliable crop to grow, and is cheaper per unit of energy to grow than grass silages.

This is particularly the case where forages are being grown on rented ground.

- In an effort to bulk up forage stocks, a lot of whole crop silage was made in 2018.

There are some very good quality whole crop pits, but we must be realistic with our expectations for whole crop.

Essentially, it is half cereal and half straw/chaff and, as a result, it is difficult to achieve a very high energy feed.

- Straw is being used on many farms to bulk up forage stocks in diets.

There is a limit to the amount of straw you can feed to fresh cows, due to its low energy density.

I have formulated milkers’ diets with up to 4 kg of straw, but this necessitates feeding a lot of concentrates.

These types of diets require very careful balancing and supervision, but have been very successful, with the right management.

Straw can easily stretch silage in replacement stock, with a balanced concentrate, these need to be higher in protein than those used to balance silages.