So how long does it take to gain 1 BCS once I dry my light cows off?

By Katrina Roberts, Anexa Vets, Herd Health Veterinarian

The answer is – always longer than you think!

Last newsletter we shared some information around the benefits of individual whole herd body condition scoring. The reason for this is that each cow/heifer needs to get to her target at calving, but each animal is different based on her current BCS, her expected calving date, her age (and if she has any compensatory growing to do) and what you are going to feed her once she is dry. Of course any underlying issues may negatively affect BCS gain as well such as facial eczema (clinical or subclinical), so if something pops up then the general rules may not apply to your cows. Remember the drying off process costs a lot of energy, therefore it is near impossible to gain BCS during the first 2 weeks after dry off, no matter how much you feed them.

The table below is reproduced from page 79 of the new InCalf book (www.dairynz.co.nz/incalf).

So how long does it take to gain 1 BCS once I dry my light cows off?


The key is that if you are going to use autumn pasture (providing it rains) to gain condition during the dry period the animals need to be dry for much longer. That is because it takes 20% more autumn pasture to gain one condition score than maize silage, pasture silage or PKE (all of which are similarly efficient at BCS gain during the dry period). If you do manage to gain some good autumn pasture growth then expecting autumn pasture to lead to condition gain while milking is plain unrealistic.

Supplements such as maize silage, good quality spring-made perennial pasture silage and PKE all are useful to add into the diet to achieve faster BCS gain (for milking or dry cows). However, when calculating the amount that you need to feed be sure to account for wastage (even when it is dry you will waste 10-15% of silage supplements if fed in the paddock).

Lets take a typical cow on the 10th March 2019:

  • Friesian X heifer (end of her first lactation) in BCS 4
  • Due to calve 15th July
  • Maize silage is available (it takes 165kgDM of 10.5ME maize to gain 1 BCS in a 500kg cow)
    She needs to be dried off on 6th April and offered 11kgDM of which 4kgDM needs to be the maize silage, this is essentially feeding her 4kgDM per day above her maintenance (on average). Obviously her maintenance requirements increase as she gets closer to calving (the fetus demands more food), therefore it is easier to put BCS on earlier in the dry period:

    • She should have been dried off last week if you only have autumn grass to feed herd.
    • If you don’t have the ability to allocate and feed her (i.e. its not in your feed budget) 11kgDM per day until the end of June then you will need to dry her off now.

  • Talk to us about how each cow in your herd can achieve BCS 5 and each heifer/second calver 5.5.




    Date Added: Tuesday, 5th March 2019


Back...