Normal variation in body condition
Compared to the average body condition, there is typically a variation in body condition of +/- 0.5 units between cows in a herd. As such, targeting an average body condition of 3.0 means that only a few cows will have a health-critical level above 3.5 or at a level below 2.5, which seriously reduces yield.
Feed intake decreases as the body condition score increases prior to calving. There is a close correlation between body condition at calving and feed intake during the first critical weeks of lactation, where the risk of strong mobilisation and consequent metabolic problems are greatest.
High-body condition herds have a higher cow mortality rate
There is a negative correlation between body condition during the dry period and cow mortality in the next lactation. Herds with a uniform body condition have fewer problems. The spread in body condition score between cows in the herd should be as narrow as possible.
Cull low-yielding cows in late lactation with a high body condition score
During periods of good prices for slaughter cows, it is usually better economics to cull cows that have a very high body condition (≥4.0), low yield (<15 kg ECM) and are more than 10 weeks from calving. In order to avoid sending cows that are late in pregnancy to slaughter, culling must always take place no later than 10 weeks before expected calving. A strategy whereby cows with a high body condition score are systematically culled will prevent disease problems due to significant weight loss at the start of the next lactation.
Ensure unchanged body condition during the dry period
The cows should always have the same body condition at calving as during the dry period. Therefore, their body condition must be controlled in the last part of lactation or by ensuring the right energy level throughout the lactation if fed with TMR.
However, cows that have a low body condition score during the dry period (<2.5), may need to improve their body condition, but it is difficult to increase the body condition score by more than 0.2 during a normal dry period and the dry period should not normally be extended for the sake of body condition.
Source: SEGES, Denmark