Back Feeding maize silage in the autumn

Date: 09 March 2015

Whether you have a stack of maize silage on hand, or a crop due to be harvested, autumn is an ideal time to feed maize silage. It can be used to extend lactation and increase cow condition, while at the same time increasing pasture cover levels prior to the winter.

Extending lactation

Producing more milk per cow should drive profitability by increasing milk revenue and diluting fixed costs.
Milksolids response to maize silage is typically high in the autumn, and any substituted pasture will increase farm cover levels which is a bonus as the farm heads into winter. The gains are even better when maize silage can be used to fill a late summer to early autumn feed deficit, allowing cows to take advantage of the autumn pasture flush.

Cows have a maintenance feed cost regardless of whether they are milking or dry. It takes about 7.5 kgDM above maintenance for a cow to produce 1 kgMS/day. The gross return (from which any other variable costs such as tractor running, casual labour, and milking costs etc. must be deducted) from doing this is shown in Table 1.

Table 1: Estimated gross return from feeding maize silage in the autumn
The numbers show there is money to be made by feeding maize silage to extend lactation into autumn, provided you can get it at the right price, and the variable costs of milking on (vs. drying off early) are not too high.

Putting weight on dry cows

The ideal body condition score (BCS) is 5.5 for first and second calvers, and 5.0 for older cows. Cows which calve at the ideal condition score will produce more milk and cycle faster than cows that are too thin at calving.

Energy in maize silage is used 50% more efficiently to put weight on cows than energy in autumn pasture. If you are feeding maize silage, you can milk for longer and still be confident you will meet cow condition score targets by calving time.

There are a number of proven strategies to ensure every cow in your herd meets the BCS target. These include drying off low producing fat cows early, giving the first calvers more time dry than older cows, and splitting dry herds on BCS and time till calving, then preferentially feeding the lighter cows.

Where cows are fed well on a mix of pasture and maize silage, cows that are in BCS 4.5 or better only require 50-60 days dry, while cows which are at BCS 4.0 or worse need 80-90 days dry.

Autumn feeding of maize silage

While the use of a feed pad is ideal, maize silage can be fed in the paddock in the autumn, as long as ground conditions are dry. To get the best response from your maize silage:

• Follow good management harvest guidelines, including the use of a quality maize silage inoculant such as Pioneer® brand 11C33.
• Minimise wastage by keeping the stack face tight and removing loose material at the base of the stack on a daily basis.
• Introduce maize silage slowly starting at 1 kgDM/cow/day and building up to the desired feeding rate over 7-10 days.
• Check ration mineral levels, especially if you are feeding more than 30% of the diet as maize silage, and/or you are combining maize silage with other supplementary feeds.

For more information on maize silage click here.