Back Extending lactation makes sense

Date: 18 February 2015

Dry conditions are reducing pasture growth rates and milk flow in many key dairy regions. Given the low milksolids payout, many are asking "Should we keep milking or dry off the herd?" While there is no recipe which works for every farm, a recent analysis by our dairy specialists shows most farmers can make money purchasing maize silage and milking on even at a $4.50/kgMS payout.

Keep cows in milk

Even in low payout year, drying off the main herd too early doesn't make sense. Even at a $4.50/kgMS payout, with cows producing as little as 0.7 kgMS/cow/day, feeding maize silage (35 c/kgDM eaten, 10.8 MJME/kgDM) generates a return of around $1.00 per cow per day. This translates to a $400/day return for a 400-cow herd (Table 1).

Table 1: Economics of milking on rather than drying off cows

Assumptions: 1. Cows will be fed maintenance even if they are dried off. 2. Farm labour costs are fixed. 3. Post grazing pasture residuals have dropped to below 1500 kgDM/ha. 4. No extra capital will be required to run the system. 5. Protein is not limiting. 6. Other costs (feed-out, shed etc.) are $0.06 c/kgDM.

Once a cow is dry, you get no milk until next season. Filling late summer to early autumn feed deficits and milking on will allow you to take advantage of any autumn flush which further improves returns.
Now is the time to assess your feed situation and plan your management strategies for the next few months. We recommend that you:

1. Use stored feed and on-farm or contracted crops first
After a reasonable spring, most farmers have a significant amount of pasture silage on hand. There is also a sizeable amount of maize silage which will be ready to be harvested within a few weeks. Feeding silages and summer crops not only keeps cows in milk but it also protects pasture cover, something that is becoming increasingly more important to ensure the persistence of modern pasture species. If you are feeding silage, always ensure that you have at least an additional 100 kgDM/cow on hand to feed when it does rain.

2. Get rid of genuine culls
Most farms have around 10% genuine culls including empties, poor performers and high cell count cows. Get rid of them now while the beef schedule is high and use the drymatter they would have eaten to better feed the rest of your herd.
For a 400-cow farm, culling 40 cows will release around 600 kgDM per day, or an additional 1.7 kgDM per day for every cow remaining on the farm. If the culls are producing 1 kgMS/cow/day, removing them from the farm will result in a decrease of 40 kgMS/day, however, using the drymatter they were eating to feed the remainder of the herd better has the potential to lift their production by up to 80 kgMS/day. The result is a net production gain of up to 40 kgMS/day. Reducing cow numbers also reduces any associated animal health costs such as facial eczema prevention.

3. Protect pastures
Many scientists acknowledge that summer over-grazing can reduce the productive life of pasture by about as much as winter pugging. Because regrassing is not cheap, protecting pastures makes good economic sense.
Cows eating silages (e.g. grass and maize silage) or summer forage crops (e.g. brassicas or forage sorghum) tend to leave behind more pasture than cows eating concentrates (e.g. PKE, meal, and grain) because they are bulkier feeds. Feeding grass silage and maize silage on either a feed pad, standoff pad or sacrifice area, enables farmers to drastically reduce the pressure being placed on pastures protecting cover levels and reducing pasture damage.

4. Watch Body Condition Score (BCS)
Achieving BCS targets of 5.5 for your 1st and 2nd calvers and 5.0 for the rest of the cows in the herd is highly profitable even at a $4.50/kgMS payout. There is no better farm system feed than maize silage to enable you to do this because it will keep cows in milk while protecting body condition and pasture cover levels.

Careful and strategic management will ensure you make the most of a challenging autumn. Your local Pioneer Representative can help you determine if milking on is viable for you. To talk to your local Pioneer Representative, please call 0800 PIONEER (746 633) or click here.


Raewyn Densley

Forage & Nutrition Specialist