Body Condition Score

Next season’s performance

Every season, in the last months of lactation, there is suddenly a frenzy of focus and activity in attempting to increase the average body condition score (BCS) of dairy herds. Each season seems to throw up its own unique challenges to achieving an ideal average BCS for your herd at dry off, so it is fair to ask the question: Why all the fuss? The crux of the matter lies in your planning for the next lactation.

Over-conditioned cows are more prone to metabolic disease - milk fever and ketosis, have lower Dry Matter Intake (DMI) post calving, and are less efficient at converting feed into milk solids. 

Under-conditioned cows don’t have much in reserve as they fire into their lactation which can result in compromised milk solids production and reproductive performance. 

Implementing strategies to minimise the number of cows in your herd that fall into these two categories is all about positioning for stronger performance next season. 

Stronger performance next season

It is widely accepted that the ideal BCS for mature cows at calving is 5.0 and 5.5 for 2 and 3 year olds. The aim is to reach these grouping targets by the time you dry the girls off and then maintain them throughout the dry period. 

Remember: nutrient requirements are not a flat rate when the girls are dry. 

All is not lost if you do still need to put some condition on your girls after dry off, however it is worth noting that it will cost you more in terms of rations consumed. In a nutshell, our motivation to reach target BCS at dry-off centers around feed efficiency.

 

1KG Bode Weight  Gain

Additional Metabolisable Energy Required

 During Lactation

36 – 40 MJ

 Dry Cow

55 – 60 MJ

 

Using our BCS scale of 1-10, 1 BCS unit is equal to 6.58% of liveweight.

 Mature Cow - 450KG KIWI X

 Index to Grain 

  1BCS = 450kg x 0.065 =29kg  

 

 Mature Cow –  450KG  KIWI X

 Liveweight needed to achieve  1XBCS UNIT

 Additional Metabolisable Energy Required

Extra Dry Matter Needed

 During Lactation

29kg

40 MJ x 29kg = 1160 MJ ME

110kg

 Dry Cow

29kg

60 MJ x 29kg = 1740 MJ ME

165kg

 

Planning

So what does this all mean in practical terms? 

Plan to:

  • Increase total ration allocations in the final 2-3 months of lactation, or
  • Consider moving cows to once a day milking if feed is tight.
  • Ration ingredients high in carbohydrate and/or digestible fibre relative to metabolisable protein enable cows to partition a greater portion of energy towards body condition rather than increased milk solids output.
  • Maize silage, whole crop silage, low protein meals or PKE will all add value to your pasture-based ration.
  • Consider the need for multiple herds in order to manipulate rations and number of daily milkings to reach your targets.
  • Finally, complete a feed budget for your dry cows now to allow proactive decision making that has you on the front foot for next season.

 

For help putting together your dry cow feed budget, talk to your Ingham Dairy Nutrition Specialist.


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