Avoid back pocket pain
Feeding supplements to extend the lactation of cull cows in a low payout year “will only hit farmers in the back pocket”.
AbacusBio farm consultant Kevin Wilson says, “culls should be dropped out of the system as soon as they can no longer be sustained by pasture alone”.
“Feeding supplements should only be fed during a genuine pasture deficit to improve potential milk solids (MS) response, improve body condition score (BCS), or to fill genuine short-term feed gaps.”
Milk production response to supplements (when residuals were less than 1500kg DM/ha) was consistently 6g to 8g MS for every megajoule of metabolisable energy (ME) fed.
“With good quality silage (of ME >11), you would expect about 75g MS/kg supplement, resulting in a return of $0.38/kg MS at a $5 payout.
“This silage is costing $0.47/kg DM after allowing for 20% wastage, which gives a $0.09 loss per kg DM offered.”
This does not provide an allowance for the cost of feeding the supplement ($0.05-$0.10/kg DM).
Instead, Kevin advocated offloading culls early to maintain pasture covers for those cows that will calve in the next spring.
“There are significant indirect benefits from culling early as this will allow more feed available to put on BCS for the animals that are being retained for the following season,” Kevin says.
“Studies from New Zealand and overseas consistently show that BCS has an important role in influencing cow reproduction, with BCS at calving being the most important BCS measure relating to fertility.
According to a published study by Roche (2007), milk yield increases linearly with increasing calving BCS (up to BCS 5).
“This suggests farmers need to focus on improving average BCS during autumn to help meet industry target BCS at calving.”
“Cows calving at less than BCS 5 will also have an extended postpartum anoestrus period, reduced potential number of breeding events, reduced milk production, and increased vet and artificial insemination costs.”
Therefore, autumn management of your herd will have a strong influence on next year’s seasonal production and fertility, Kevin comments.
“By identifying and offloading culls when pasture alone can no longer support intakes in late summer or autumn, you will make this season a more profitable one, as well as the next.”
Sourced content from NZ Dairy Exporter
Photo credits to NZX Agri