Transition Success

Transition Success    By Helen Rogers and James Husband

It is well recognised that the primary factor determining the success of your transition period is Dry Matter Intake (DMI). At the XLVets Transition Cow Roadshow last year, Steve Le Blanc presented data illustrating that 82% of DMI in dry cows is determined by management and not body condition score (BCS), diet formulation or parity. Driving DMI in your dry cows and fresh calvers is relevant regardless of the management system, breed, yield or parity of the dry cows. As an example, in a dry Holsteins, a 1kg/day decrease in DMI doubles the risk of subclinical ketosis post calving.

The ultimate dry cow management to maximise transition success would include:

• 3-5% of the ration left over every day
• 30 inches (75cm) feed space per 750kg cow (or 4 cows per 5 head yokes)
• Feed trough depth that allows access to all of the diet put out
• Two sources of water per dry cow yard
• Adequate water supply to allow for 4 litres of water to be drunk per kg DMI

Great success in driving DMI has been achieved by feeding dry cows twice a day. Provided the diet can be protected from the elements, it can be mixed once a day and then stored prior to putting it out as a second feed.

Supporting at risk cows:

What are effective interventions for ketotic cows?

Several feed additives have been extensively researched:

• Propylene glycol…: The cow can use glycol to make glucose which is required for milk production and will be in short supply after calving. This is effective at doses of 300ml/day given for 3 to 5 days.
• Calcium propionate….: Used by the cow to make glucose, this has the added benefit of providing calcium too. This needs to be supplied at 400-500g per day.
• Choline… A recent review paper looking at the most effective treatments for fatty liver concluded that consistent improvements were only seen if energy sources (propylene glycol) were given with choline. The choline acts as an antioxidant and helps the cow produce the transport protein that clears the liver of fat (methionine can do a similar job). An analogy is that the propylene glycol is the fuel in the tank of the car but unless the engine is running well, the car won’t run well. The liver is the metabolic engine of the cow and unless it is healthy immunity, and milk production will be compromised.

How to supplement choline?

Choline can be supplemented in the transition ration to the point of calving, but unless a herd has a fresh cow group it can’t be supplemented post calving without giving to the whole herd. Targeted dosing can be achieved using boluses. Trial work looking at yield response, has shown these to be most effective when given:

• At or soon after calving to fat cows that carry a higher risk of excess fat mobilization. In the trial, bolused cows that were condition score 3.5 or above gave an average of 5 litres more milk at the first recording compared with similar cows that were not supplemented.
• In conjunction with energy precursors such as glycol, to cows that have subclinical ketosis, to allow the liver to function more effectively.
• To sick cows post calving which will be mobilising fat and be in poor metabolic health probably with other appropriate treatments depending on the disease present.

Use of Choline is a relatively new tool in the management of cows who are at risk for transition ‘failure’. Please do speak to us to find out whether this could be a suitable tool to help these problem cows and to identify ways to maximise your DMI in your dry cows.

Many thanks to James Husband for providing content for this article.