Why Dry Cow Management Matters

Published 1 October 09

DairyCo is currently running a series of feeding+ Dry Cow Management events based around part of the feeding+ programme.  Extension Officer Hugh Black talks about why it is such a crucial period, the important aspects of dry cow management, and some of the new thinking in the area.

"Good nutrition and management in the dry period have been shown to minimise calving problems and early lactation metabolic disorder, maximise subsequent lactation performance and udder health, and optimise fertility," says Hugh.

"The period deserves particular attention because of the extent to which it can make the difference between success and failure in overall herd performance."

Dry Matter intakes and energy requirements

"The growing calf will physically restrict rumen capacity and through it appetite in the dry period, but relatively low energy requirements at this stages mean this presents few if any feeding problems. 

"Typically dry matter (DM) intakes vary from 1.7% to 2.3% of bodyweight during the dry period and whilst intakes will drop off close to calving you won't really see any real decline until the last few days. This means a 600kg cow, that can eat 2% of its bodyweight in DM each day has an intake of around 600 x 2 ÷ 100 = 12.0kg/day. "It is also important to keep the rumen full in order to minimise the risk of displaced abomasums.

"The primary aim of dry cow feeding is to maintain body condition by ensuring adequate energy intake. On top of normal maintenance requirements, extra energy is needed in late pregnancy to support the growing calf. More than slight under feeding of dry cows will lead to excessive fat mobilisation and this can go unnoticed unless cows are routinely conditioned scored.

A typical Holstein/Friesian dry cow requires 15% of its body weight plus 10MJ of ME each day to maintain body condition. This means a 600 kg dry cow requires (600 x 15 ÷ 100) +10 = 100MJ of ME/day

"Routine condition scoring will also help prevent over-feeding which raises insulin levels to enable excess energy to be stored as fat. This makes cows less responsive to insulin reducing energy intakes and increases weight loss in early lactation. 

Mineral and vitamin requirements

The mineral requirements for dry cows are low compared to milking animals but the incorrect mineral balances in this period can cause:

  • Difficult calving  - as a result of poor muscle tone;
  • Retained cleansing - due to poor uterine contractions;
  • Milk fever - which can lead to reduced feed intake and displaced abomasums;

The main minerals to consider in minimising problems are;

  • Calcium;
  • Phosphorus;
  • Magnesium;
  • Potassium;
  • Sodium;

"All these minerals are related to calcium supply which is critical in view of the sudden, dramatic increase in requirements at calving and the relative immobility of body reserves. The cow's metabolism needs to cope with the three or four fold increase in daily calcium requirements at calving.

"The cow's body reserves of calcium in bones are high, but the diet can significantly influence the speed and extent to which these can be mobilised.

"There are three things you can do to influence this. Feed a low calcium diet pre-calving, this improves the efficiency with which dietary calcium is absorbed and stimulates increased mobilisation from bone.

"Feed extra Vitamin D very close to calving in order to increase short term bone mobilisation and gut absorption.  A Vitamin D injection 24 hours prior to calving can give the necessary boost to calcium supply it can be difficult to accurately asses when some cows will calve. This is important as the same injection given 3-4 days prior to calving can actually increase the risk of milk fever.

"Feed a Dietary Cation-Anion Balance (DCAB) system, which balances the minerals naturally present in the feeds to ensure the most favourable, slightly acidic conditions in the bloodstream.

"The dairy cow's dry period is one of the trickiest areas to manage, but if you can get it right it will really help to set her on the right track for a successful lactation. At the feeding+ dry cow management events we will  looking at issues such as feeding, health and disease problems and how to make calving as stress free as possible for the cow. 

"These event are a great chance to pick some experts minds and find out how other dairy producers are tackling these issues."

New thinking on dry cows: Length of dry period?

The traditional eight week dry cow period is being challenged and there are definite advantages to a shorter dry period. The eight week period developed before routine antibiotic use and now it is being questioned. Research has shown that cows with low cell counts repair udder in three to four weeks so you don't necessarily need 8 week dry period. But it's important to CMT all quarters eight weeks before the calving date to check for high cell count. A shorter dry period makes a one group system easier to manage and gives extra milk at the end of lactation. A short dry period may also reduce peak yield in the next lactation, and a lower peak yield means less weight loss and a quicker return to breeding.

One or two groups of dry cows?

There are arguments for and against running one or two dry cow groups.

One group

Two groups

 

 

Rumen conditions held more stable

Early dry cows can graze effectively

Reduces the time and stress to cows involved in sorting cows between groups

Less risk of cows with long dry periods getting fat

Easier to check all cows

Fewer cows close to buildings or in yards

More expensive if using DCAB minerals

You can pay greater attention to cows approaching calving

Cannot use off-lying land