Pros and cons of 5 close-up dry cow feeding options

The close-up dry period is a critical period in the last three weeks before calving.

It is essential to the success of the next lactation and rations should change to prepare the animal for lactation.

Forages low in energy are a must as it is essential cows don’t put on or lose weight.

See also: How to assess if your dry cow ration is working effectively

Together with independent nutritionist Mark Price, we take a look at five options for dry cows.

1. Goldilocks diet

What it is?
The Goldilocks diet is low in energy and high in low-quality forage, typically straw, and fed for the entire dry period. 

The term “Goldilocks” is derived from the fact cows are provided with just the right amount of nutrition. This means the cow’s energy requirements will be met, but not exceeded when they are fed the diet ad lib.

How does it work?
By feeding the cow just right amount of energy, there is a lower rate of fat mobilisation. This is because cows’ tissues become more insulin sensitive, and insulin is a hormone that reduces fat mobilisation.

Many Goldilocks diets are also dietary cation anion balance (DCAB) diets. This means they contain a balance of minerals that acidify the blood, which promotes calcium mobilisation from the bones (see point 2).

Vital elements of the ration/inclusion rates
Typically, the diet will contain:

• More than 50% forage.
• Low levels of grass silage (ideally no more than 3kg a head a day).
• 2-3.5kg a head of dry straw (high quality, low energy and chopped short).
• Crude protein is 13.5-15.5%.
• At least 1,200g of metabolisable protein.
• Neutral detergent fibre is 40-50%.
• Micronutrients are dependent on factors such as milk yield and raw material bioavailability.
• Potassium as low as possible.
• Magnesium to potassium ratio is 1:4.

Pros

• Good at keeping the rumen full and because less grass silage is used, the risk of milk fever is reduced because the energy density of the ration is kept low.
• It can be fed to one group throughout the entire dry cow period.

Cons

• You must be able to chop high-quality straw down to 2cm and ensure cows eat it.
• It is not the cheapest diet as the straw brings no nutritional benefit.

What type of herd is it suited to?
This diet is suited to mid- to high-yielding herds (7,000-12,000 litres) because it is effective at controlling milk fever and ketosis, both of which are present in higher yielding herds.

2. DCAB diet (semi-DCAB and High-DCAB)

What it is?
The DCAB system is probably the most common modern dry cow feeding approach to help prevent milk fever. It involves balancing the minerals naturally present in the feeds to create the most favourable, slightly acidic conditions in the blood.

The difference between a high-DCAB and a semi-DCAB is the level of acidification ­– a high-DCAB (full) diet causes the blood to be more acidic.

A semi-DCAB (partial DCAB) contains less anionic salts meaning the blood is less acidic. Magnesium chloride is the main anionic salt used in both diets.

A high-DCAB diet involves the use of a commercial mineral pack (supplement) containing a balance of anionic salts and additional calcium. This works well under careful management, but high calcium can make milk fever worse if the supplement is not fed accurately every day.

How does it work?
It acidifies the blood which allows calcium to be mobilised from the bones.

To acidify the blood, you need to offset the inputs of positively charged cationic salts such as potash and sodium, which make the blood less acid, with acidifying, negatively-charged anions like chloride and sulphate.

This essentially causes the cow to get mild, metabolic (not rumen) acidosis which triggers the metabolism of calcium from the bone reserves to redress the balance and prevent milk fever.  

Vital elements of the ration/inclusion rates
The rations of a high-DCAB and semi-DCAB diet are similar except for the mineral pack.

The diet includes:

• 2-4kg a head of straw (no higher than 6kg a head).
• Ideally, low levels of grass silage (typically no higher than 10kg a head) to keep potassium levels low.
• Typically, 5kg/head a day of hay/haylage (not essential).
• Maize silage.
• 2kg a head a day of concentrates.
• Mineral pack – the pack will depend on whether it is a full or semi-DCAB diet and also the base ration of the diet. The semi-DCAB mineral pack will contain less anionic salt.

Pros and cons

• High-DCAB diet can be more expensive.
• Can be hard to manage and needs to be accurate. Blood acidity will need monitoring by testing the pH of the urine.
• A semi-DCAB diet is slightly cheaper because of the mineral pack contains less anionic salts. However, the semi-DCAB diet is less effective in minimising milk fever in high risk animals such as high-yielders.

What type of herd is it suited to?
High-DCAB to high yielding herds and semi-DCAB to high- (10,000 litres plus) and medium- (7,000-9,000 litres) yielding cows.

3. Calcium binders

What it is?
Calcium binders are granular compound clay pellets that bind excessive calcium in the diet (for example, if a high amount of silage is being fed.) They have been found to decrease the incidence of milk fever and are often used where high amounts of grass silage is fed in the dry cow diet.

How do they work?
Some of the products are based on sodium aluminium silicate, which is a synthetic zeolite clay that binds calcium. This causes the cow to mobilise calcium from her bones when she needs it.  Binders are often sold as a compound dry cow nut.

Vital elements of the ration/inclusion rates

• 20kg ahead a day of grass silage.
• 2kg a head a day of straw.
• 2kg a head a day of concentrates.
• Roughly about 500g of zeolite (calcium Binder) although many complete formulations include the zeolite and the concentrates.

Pros

• Feeding a calcium binder is one of the most robust and reliable ways of stopping milk fever.
• It allows farmers to feed high amounts of grass silage which can be high in calcium.

Cons

• Expensive.
• Only prevents milk fever and not other metabolic diseases such as ketosis.
• Needs precise management of the zeolite – it cannot be fed at all post calving.
• Some farmers can be so reliant on the binders, the ration often receives less attention.

What type of herd is it suited to?
Small herds/all year round (AYR) small calving groups or herds that may struggle to source and chop straw, and where grass silage is the main source of feed. It also suits farmers that graze dry cows.

4. Standing hay for grazing herds

What it is?
This is where a field is left to grow for two months and then strip grazed. It provides cows with a high fibre, low-energy diet.

How does it work?
Instead of incurring the cost of baling long, stemmy grass for silage or hay, cows harvest it themselves by strip grazing it. The paddock can also double up as a calving area.

Vital elements of the ration/inclusion rates

• Cows typically eat 8-10kg of DM a head a day.
• For very low yielders, no supplementation will be required.
• High yielding cows will need to be supplemented with dry cow rolls or nuts.

Pros

• It is the cheapest diet ­– the cost of grazing standing hay is only 7p/kg of DM and for the total ration cost, you are talking pence not pounds – half the price of other diets.
• Works well for farmers managing dry cows outdoors or calving outdoors.

Cons

• Weather can reduce the DM intake and affect the hygiene of the cow and calf.
• If calving outside, ensuring good colostrum intake in the calf can be trickier to manage.
• Potentially there’s a higher risk of metabolic diseases in higher yielding cows if they are not receiving the correct dry matter intake.

What type of herd is it suited to?
Smaller cows and low-yielding cows (below 7,000 litres). It also works better logistically for an autumn calving herd.

5. Simple forage and dry cow nut

What it is?
A forage-based ration such as haylage supplemented with a dry cow nut is the simplest dry cow ration available.

How does it work?
This diet is reliant on forage. The dry cow nut is used to address any protein and energy needs with minerals often fed in addition. The diets are often semi-DCAB which helps acidify the blood slightly and causes mobilisation of calcium from the bones.

Vital elements of the ration/inclusion rates

• 25-30kg a head a day fresh weight of forage.
• Dry cow nuts should be 25% protein, 18% starch and an ME of 12.5% and fed at a rate of 2-3kg a cow a day.
• Overall ration ME of 10.5ME.

Pros

• Simple diet and be very effective.
• Works well with small groups.
• Can be flexible.

Cons

• If you do have issues, it can be hard to adjust.
• Reliant on forage.

What type of herd is it suited to?
Lower yielders and cows housed in smaller groups where feeding multiple diets would be hard. i.e. if there are only a few cows in each group.