If we consider when we most often have to look at the implications of dry weather, it is in the months of January through to March so when thinking about how to manage this we probably first need to think about what we are trying to achieve over this period
Hopefully, during this period most of our cows are in calf, they have passed their peak lactation and are now on the steady decline as they move through their lactation; they have a calf onboard, but this isn’t drawing a lot from them. What they are trying to do though is potentially replenish some of the body condition they have given up to us in early lactation via the milk!
If we consider the cow at this stage doing say 1.0-1.2kg milk solids (MS) then for a Jersey x Friesian she is going to need around 12-14kg dry matter intake (DM) at an energy density of 11MJ ME. This is probably more than current pasture is providing so this will increase to 13-15kgDM at 10.5MJ ME, so the lower the energy density of the feed the more we need to use; unfortunately, as feed quality declines so too does the ability for DM intakes. If she is walking over rolling country, then add another 3 MJ ME/km and 50MJ ME/kg liveweight (LW) gain. This works out for a cow needing to gain 0.5kg LW per day (or 1/2 BCS in a month) and walking 2km/day to (1 x 25 + 3 x 2) equals 31 additional MJ ME/day or an additional 3kgDM approx. at 10.5MJ. Total required therefore is 16-18kgDM.
So how do we get this into them? Feed is running short, so they have to work a bit harder for it and now is not the time to be dropping BCS for the sake of maintaining production. It will cost you far more to put this body condition back on later and will be more detrimental for a host of other reasons. It is therefore important to monitor BCS every 3-4 weeks to make sure of where they are heading! Ways to manage the BCS are to get all known culls off ASAP, don’t carry them for the sake of it as it is another mouth to feed when things are tight, and they probably aren’t paying for themselves. Dry mature animals off based on BCS and somatic cell count (SCC). Drying off low producers and young stock early when they are in good condition will be far more beneficial and will reduce pressure on available resources. When drying groups off though you need to ensure their intakes are also adequately maintained, don’t forget about them!
Feeding supplements can help to maintain production and provide relief to grazing by enabling you to extend the round, its important though to remember that you will need supplements on hand for winter. Make sure you plan to keep feeding supplements for a further 10-14 days after rain comes as it will take this time for pastures to recover! Depending on the choice of supplement they will also often increase water demands so making sure you have troughs that are working and are plentiful is also an important management step, the drive to drink in hot weather will also be increased.
Remember also that choice of supplement is important as Maize silage, for example, is low in protein whereas good quality grass silage is higher so would be a better first choice for maintaining production levels. Other options such as Palm Kernel Extract or Tapioca (or blends of these) are an option but always consider the value proposition of these before purchasing and be aware that increasing levels in the diet will increase the Fat Evaluation Index (FEI) results you are getting!
Discuss options around feeding with your farm advisor or vet as a sounding board to help with the decision-making process but chasing production can be detrimental.