There is a risk that cows on some dairy farms could become over-conditioned as a result of early dry off and excellent autumn grazing conditions, according to Teagasc.
Teagasc says getting cows to the correct body condition score (BCS) at calving reduces health problems after calving, improves conception rates and boosts milk solids production next season.
In its latest update for dairy farmers its target BCS for cows at calving is 3.25 with an acceptable range of 0.25 units above or below this point.
Teagasc says most dairy herds are in relatively good condition this year following an excellent grazing autumn. However, it also notes that there are always individual animals falling behind target so herd average BCS is not a very useful measure overall.
On the other hand, Teagasc stress there is a real risk of over-conditioning in some herds where cows were dried off early due to quota issues. Therefore, it says the focus should be on using the BCS of individual animals to make decisions on a cow-by-cow basis.
Teagasc outline in Table 1 the projected BCS changes for feeding ad lib silage at different DMD for an eight-week dry period, plus the additional effects of a longer dry period or extra feeding.
For example, it shows that cows fed standard 68% DMD silage for eight weeks dry will gain 0.20 of BCS, but an extra six weeks dry will increase that gain by a further 0.45 units. Cows offered 72% DMD silage for 14 weeks dry will gain over 1 BCS unit, so feed restriction through December and January for later calving cows would be required.
Cows will lose BCS on low quality 62% DMD silage over an eight-week dry period; extending the dry period on very poor silage has only a moderate effect so extra feeding may be necessary if BCS gain is needed.