31 Mar Body condition scoring – a tool for dry-off strategies

It is that time of the year again when it is time to start planning dry-off and make sure you are well set up for the next season. Did you know that body condition scoring your herd can be a great tool for planning your dry-off to make sure your cows are reaching target body conditions for calving and mating next season?

What is body condition scoring?

Body condition scoring cows is a way of estimating how much fat the cows are carrying, which is an indication of their health and energy reserves. Eight points on a cow are used to evaluate the body condition score (BCS) of the cow: backbone, long ribs, short ribs, hips, rump, pins, tail head and thigh. The BCS scale in New Zealand runs from 1 -10 where 1 is completely emaciated and 10 is very obese. Typically, dairy cows will be between 3.5 and 6.5. If the BCS of a cow falls below 3, urgent remedial measures must be taken.

For more information on body condition scoring have a look at the DairyNZ website:

Body condition scoring (BCS) – DairyNZ | DairyNZ

How to use body condition scoring to plan dry-off?

Mixed age cows should have a BCS of 5 at calving, and heifers should have a BCS of 5.5. Did you know that rising 3-year-olds also should have a BCS of 5.5 at calving? This is because they are still growing and therefore need to carry extra energy reserves. This is a group that is often “overlooked” and this can be a cause of increased empty rates in your herd if they are not meeting target condition scores at calving and therefore most likely also not at mating.

Generally, cows cannot gain more than 0.5 condition score in one month and they do not gain any condition in the two weeks after dry-off and in the two weeks before calving. This means that for a cow to gain 0.5 condition score after dry-off the cow will need at least 60 days. If a cow needs to gain 1 condition score, she will need to be dried off at least 90 days before calving. These numbers can be used together with BSC, target BCS and expected calving date to determine appropriate time to dry off.

Below are a few examples:

• In these examples an expected calving date of 1^st of August is used.
  • If a cow needs to gain 0.5 score she would need at least 60 days so she should be dried off before 1^st of June.
  • If a cow needs to gain 1 score she should be dried off before 1^st of May.
  • If a cow needs to gain 1.5 scores she should be dried off before 1^st of April.
  • If a cow needs to gain 2 scores she should be dried off before 1^st of March.

By body condition scoring your cows around February/March you can use the scores to develop a dry-off strategy. Perhaps you have some lighter cows that are early calvers that you want to dry off early to make sure they reach target BCS at calving. At the same time, you might also have some well-rounded cows that do not need to be dried off early and that need to be monitored, so they don’t get too fat causing metabolic issues. You might also want to run two dry mobs, one “skinny” and one “fat” so that the amount of feed offered can be tailored to whether the cows need to gain condition or whether they need to be monitored to not be over conditioned.

When planning dry-off based on BCS you also need to consider feed availability and whether this is sufficient to support BCS gain while also achieving target pasture covers, taking into account timing of heifers returning home and thinking about when to remove culls. When BCS gain is required, extra feed needs to be available above maintenance requirements over winter, keeping in mind that some types of feed are achieving condition gain better than others.

Every herd will always have a spread in BCS but by body condition scoring cows and developing a dry-off strategy the spread in BCS can be reduced and the number of cows at target BCS at calving increased.

How to body condition score your herd?

Your local farm consultant might be able to score your cows, or they might know who you can ask. If you would like to learn more about body condition scoring, DairyNZ has some good resources on their website. There is also a list of certified body condition scorers on the DairyNZ web pages and information on how to undergo training and become a certified assessor yourself:

BCS Certified Assessors – DairyNZ | DairyNZ

Our DTT Gibson farm in Hawera hosts some of these body condition scoring courses and recalibrations.

In summary, BCS can be used as a tool to develop a tailored dry-off plan for your herd to help ensure that all cows reach target body condition score before calving.