SealesWinslow’s Head of Product Development, Dr Rob Derrick, takes us through options for dealing with late lactation.
Dairy farmers face a conundrum: how do you support dairy cows nutritionally in late lactation?
Late lactation supplementary feeding may fill a feed deficit to ensure cows are fully fed. This can also safeguard pasture covers to avoid overgrazing and recovery for the winter.
In some regions however, extreme weather during 2024 delayed the sowing of maize for silage and winter fodder crops. This adversely impacted homegrown feed supplies that would normally support weight gain during dry periods.
Some higher input systems may be looking to increase the days in milk and dry off cows at target condition scores. With spring calving cows, there is an opportunity to supplementary feed when there is perhaps more confidence about the payout.
Forage supplementation decreases pasture dry matter intake more than concentrate so can have a bigger effect on pasture residuals if covers are low. Where improving residuals is not the primary concern, concentrates can support weight gain and milk production more than forage supplements.
Directing more nutrients to improve body condition in late lactation cows can mean more days in milk (if cows are dried off based on BCS).
With so much variability in weather patterns, which can reduce feed utilisation and strip cows of condition, there is some value in supporting weight gain when you can. Cows can give more milk, have a lower carbon footprint and get pregnant with a shorter mating period provided they receive the correct nutritional support throughout the entire year.
The quality of supplementary feed concentrates adds another layer of decision making.
One challenge has always been how to value grains in late lactation without the added benefits of starch during early lactation in terms of days to first oestrous and submission rates. Profitability is not always down to minimising cost and late lactation can prove a costly time if false economies are made.
Calculating the right mix
The SealesWinslow Ruminix3 diet calculator has been based on the internationally respected Cornell University Net Carbohydrate and Protein System. It calculates a higher response from rumen fermentable carbohydrates than some other systems. It reflects what a lot of farmers know, that grains can deliver more milk and weight gain than high fibre or fat by-products.
The calculator also includes estimates of both major and trace mineral requirements and supply. Trace minerals are not associated with the downer cows issues seen with major minerals. Their effects are more subtle, and deficiencies are harder to detect.
A range of liver and blood tests can be helpful to show how well supplementation is meeting requirement – especially if you have been encouraged to cut costs post-Christmas and saw minerals and trace elements as low hanging fruit.
Cows will mine their mineral reserves in early lactation to meet the needs of the calf and at some point the reserves have to be replenished. Trace minerals work like catalysts to speed up biochemical processes within animals. While some reserves can be called on to meet requirements, it can be prudent to meet demand rather than let deficiencies build up.
Balance is important. Regional advice can be less valuable than specific advice based on a review of your cows at a particular time. The Ruminix3 calculator, coupled with local knowledge, is one way to separate the essentials from the nice to haves.
Talk to your local TSR or visit a Farm Source store to discuss late lactation options and how Ruminix3 can calculate feed options.
Article supplied by SealesWinslow.