Most herd in this district hit peak lactation figures in early November. Ideally the lactation peak holds for as long as possible. A >7% drop in production/month after peak is considered excessive and likely indicates issues with a net reduction in ME intakes of cows.

A significant drop in production in the pre-mate and mating period will often see cows dropping in condition at the same time. This is not an ideal situation for optimising embryo quality and pregnancy maintenance.

So, what are the most common reasons for herds coming off peak lactation?

Dry matter percentage

The excessive intracellular water (internal), as opposed to rain on the surface of grass (external), has been shown to restrict voluntary intake. Studies have shown a reduction of dry matter intake of 0.2-0.3kg DM for each percentage drop in dry matter below 15-18%. After a period of wet weather and good growing conditions this might see voluntary intakes drop from 18kgDM/day to 15kgDM/day if the dry matter percentage dropped from e.g. 18% to 12%.
Mowing in front of cows several hours before grazing to get wilt should increase intakes if dry matter % is low but of good quality.

Quality of pasture

Grazing pastures more mature than the 3-leaf stage (2-3 is optimal) will show a marked drop in ME. Grazing to low residuals where previously rounds have been lax means a higher percentage of mature/dead DM must be eaten, this reduces ME of the grass eaten as well as voluntary intake.
If pasture cover is greater than 3,400kgDM you are best to top behind cows rather than mow in front, so as to not force them to eat poor quality feed.

Quantity offered

Low pre-entry covers, restricted areas and simultaneous removal of concentrate supplements.
Continue to calculate pre-graze covers and adjust break size or supplement as appropriate.

NDF percentage

Cows cannot eat more than 1.3-1.5% of their body weight in NDF (this would be 7.5kg for a 500kg cow). If targeting cows to eat ≥18kgDM, the maximum NDF content would be about 40% of the diet.
Ensure that covers do not exceed 3,400kgDM/ha at this time of year, and don’t force them to eat low quality residual.

Weed takeover

Californian thistles and dock can become a significant problem on some farms at this time of the year. They effectively reduce the grazing area.

Heat stress and water restriction

Temperature Humidity Index, air movement and solar radiation in combination will have a combined effect on the cows ability to maintain a normal body temperature. This in turn will affect grazing behaviour and grass harvest. Having shade and available drinking water (exit races) is pertinent to regulating body temp. Bringing cows together in close proximity in the yards/shed over the hottest hours in summer increases this risk.
Watch for cows panting. Aim to provide the biggest feed allocation in the coolest part of the day in hot weather and adjust milking times.

Concentrate removal

Often in-shed concentrates are removed as financial budget for purchases is reached or there is an anticipated excess in grass. The removal may coincide with any of the above to reduce total ME intake at what may be a crucial time.

Lameness

If a significant percentage of the herd does become lame (and this could be slight), there is an associated increase in lying time as cows try to rest their feet.
Monitor walking times of cows. If this is slow due to lameness adjust management or seek help from your Prime vet.

Milking interval