Managing autumn calving cows

Graham Haugh
Territory Sales Manager – Central Waikato & South Auckland

Autumn or split-calving patterns are now a reality for many dairy farmers. The following practical tips can help set your autumn-calving cows up for a productive season.

Dry cows and transition feeding: Summer has been tough for many in the top half of the North Island, meaning body condition score may not be ideal at drying-off (4.5 BCS minimum). Don’t attempt to put on rapid weight with low BCS cows using low protein maize silage as lower intakes will occur at calving and more bodyweight will be lost after calving. Aim for BCS 4.5 by feeding to the increasing nutrient requirements of your cows as they move towards calving. Ensure cows are kept rumen stretched and full in the dry and transition periods. Most cows will require 120–145 MJ ME daily, so don’t be afraid to increase dry matter intake.

Preventing milk fever and associated metabolic diseases: While the incidence of milk fever tends to be lower in autumn due to lower pasture intake, it can still occur at a sub-clinical level. Implementing optimum magnesium, breed appropriate DCAD rations and intakes, in combination with a bio-active form of Vitamin D (i.e. Hy-D®) will ensure ideal blood calcium levels.                   

Ensure you meet protein requirements: Sufficient protein is critical for stimulating DMI in late gestation dry cows and ‘firing up’ the mammary gland for a productive season.1 If you are planning to feed maize silage due to low pasture availability or quality, then add a high quality protein supplement. PKE is a low quality protein feed, which is inadequate to meet the total protein needs of highly productive dairy cows.

Protein deficits are all too common with Autumn-calved cows when pasture protein supply is limited and decreasing into the winter months. Grass silage is often mainly non protein nitrogen also (NPN, not true protein as amino acids). With winter milking protein deficits, cows look full and in good condition but milk production is frustratingly disappointing. Protein deficits can be fatal to good fertility results. Fertility problems are compounded where cows have ketosis or sun-clinical and clinically low blood glucose levels. Anti-mating winter weather events, require careful energy management for the mating job to be successful.

Keep an eye on digestibility and forage-to-concentrate ratio: Achieving high peaks (>2.2 kg MS daily) from fresh autumn-calving cows consuming high levels of conserved forage can be challenging. Cows consuming high levels of fibre from forage consumption will often ‘tap out’ for appetite before they have consumed sufficient nutrients to support high levels of milk solids production. You will need to change the forage to concentrate ratio of the ration, resulting in an improved forage NDF:NFC (non-fibre carbohydrate) ratio. Refer to Tables 1 and 2 (below). PKE and pasture silage can be reduced accordingly as pasture availability increases. Margin over feed costs (MOFC) may sometimes take a hit for a short period of time in order set your herd up for the season and reduce BCS losses.

Balance macro and micro minerals: Cows require access to a balanced combination of essential macro and micro minerals and vitamins to support optimal health, fertility and production. Deficiencies can be observed in cows that are fed high levels of maize silage and PKE. CopRice pellets include limeflour, di-calcium phosphate, salt, magnesium oxide and magnesium sulphate to reduce the incidence of metabolic issues. Pelletised feeds provide a great vehicle for supplementing minerals to your herd with accurate distribution to every cow.

Target high profit margin potential. Winter milk pricing is also quite an incentive to push productivity along. With contracted winter milk now attracting up to a $3.50/kg MS premium for June and $2.85/kg MS during the shoulder periods in May and July, the financial opportunity can also be utilised to the advantage of your business.

Table 1: Winter milk maize silage scenarios

Table 2: Winter milk grass silage scenarios

 References: 1. Appuhamy et al., J Nutr. 2011.

Contact your local CopRice Territory Sales Manager for more information about how we can help to deliver a cost-effective, balanced ration for your autumn-calving cows.