Aim to have all heifers fit to breed in April
If you are not a great judge of weights, you might call in the Farm Relief Service or some one that can help.
Time is quickly passing for bringing backward animals back on track for early breeding, and bringing backward in-calf heifers up to target.
Aim to have all heifers fit for breeding in April.
The consequences of not doing so are very serious.
It will result in breeding heifers too light, which can reduce yields more than 150 gallons in the first two lactations. Or calving too late can results in a cycle of late caving, or calving at almost three year olds, which is very costly.
We are facing into a period where there may be a premium for February milk, in order to reduce peak supplies. Therefore, start building a compact late January and February calving herd — best done by starting with the heifers. In the vast majority of cases, this will result in longer lactations and more efficient milk production from grass.
Calving patterns are improving, due to more fertile heifers and better management, but about 25% of cows calve after late March, so there is plenty opportunity to bring forward calving dates.
ICBF calving reports indicate that only about 54% of dairy heifers calve at the target age of 22-26 months (statistics based on over 10,000 dairy herds).
The data also indicate that the top most profitable 5% of farmers calve all their replacements within the target age, while the bottom 5% calve none within the target age.
Replacement Targets
Holstein/Frisian (HF) heifers should be at least 340kg in April for breeding. That gives about 80 days from now to adjust feeding. Moorepark data suggests that with average silage, weight gains will be about 0.35kg per day or 28kg in 80 days. Getting them to grass early will help, but can not be relied on. Silage plus 2kg of 18% protein concentrate with suitable minerals should give weight gains of about 0.6kg per day, or 48kg in 80 days.
Based on these figures, heifers need to be over 300kg now to be on target for April breeding, on silage alone. Heifers weighing around 265kg, getting silage plus 2kg of concentrates, will be slightly short of target, but an extra few weeks on good grass, or a slight delay in breeding, should have them OK.
Lighter heifers should get good silage and at least 2kg of concentrates. Aim to get them to grass as early as possible and perhaps breed in May.
Heifers should be grouped and fed according to weight.
Make sure they are free from parasites.
If at all possible avoid late calving heifers.
Several Teagasc trials show that weight is more important than age at calving. April born heifers can be calved down successfully in February at 22 months if reared properly from birth.
The minimum breeding target for NZ/FR in April is 320kg, and 305kg for Jersey x HF.
Some farmers prefer heavier weights at breeding.
HF in-calf heifers should calve down at 550kg (minimum), NZ/FR at 525kg, and Jersey x HF at 490kg. Their weights and condition scores should be carefully assessed now, and remedial action taken where required.
