Focusing on the First 100 Days Post-Calving

During the dry period, cows should be fed to meet, but not exceed, their maintenance and pregnancy requirements in order to prevent excessive body condition gain and support maximum dry matter intake (DMI) in early lactation. Post-calving and now entering the second part of the transition period, this cow now has the potential to yield anything from 20-60 litres, depending on her genetic makeup. But in early lactation, this modern and productive dairy cow cannot physically eat enough to support her requirements for maintenance and milk production, and she enters a state of negative energy balance (NEB). How the cow and farmer deal with the energy demands of this period will determine the success of not only this period but the full lactation.

What farms are trying to achieve is to:

• minimise incidences of metabolic problems post-calving;
• maximise dry matter intake and balance protein and energy intake;
• reach target peak milk yield;
• control loss of body condition; and
• reach positive energy balance to ensure good fertility.

As well as looking after their animals, farmers also need to derive a profit from animals and milk sales. Hence, they need to achieve this as efficiently and as cost-effectively as possible. Focusing on a number of key areas, outlined below, will go a long way in determining the performance and profitability of any herd.

Body condition score

The NEB will cause an animal to mobilise body condition. When cows lose body condition, the fat is broken down in the liver. This produces substances like ketones, which can build up in the body and reduce appetite, and can lead to problems such as ketosis, poor fertility, and a weaker immune system. The graph below (Shaumann, 2015) outlines the cycle of milk yield, dry matter intake and NEB during the transition period.

If calving at an ideal condition of 3 to 3.25, it is somewhat acceptable for cows to lose up to 0.5 BCS units after calving in early lactation. A larger loss can compromise the health, production and fertility of the animal. Research conducted by Teagasc (1999) demonstrated that cows losing more than 0.5 body condition score (BCS) units during early lactation experienced an 8 per cent decline in both six-week calving rate and conception rate. This reduction in reproductive performance was estimated to result in a financial loss of €66 per cow (Shalloo, 2014).

Nutrition

A nutrition plan should be based on first increasing the dry matter intake of the cow quickly and safely, to meet her energy, protein and fibre requirements. This will be achieved by using good-quality forages and concentrates, especially when the cow’s rumen is adjusting to larger amounts of different feeds. Nutrition is a vital part of avoiding excess BCS loss.

Energy

Energy will be supplied through combinations of sugar (e.g., grass and molasses) and starch (e.g., grains). The target is to have 20–25 per cent starch and sugar in the diet, but sometimes this is difficult because forage usually makes up at least 50 per cent of the diet. The quality of this forage is generally average at best, so providing access to a second, higher-quality forage is recommended.

Based on average silage (68 per cent DMD), the following concentrate levels are needed to supply adequate energy levels in either a total mixed ration (TMR) or separately:

Protein

High-protein diets are expensive and can drive intake and peak milk yield in early lactation, which can exacerbate BCS loss. Overall protein can be reduced by balancing the diet’s degradable protein (e.g., grass, distillers’ grains, rapeseed), undegradable protein (e.g., soya bean) and fermentable energy sources.

Excess protein has to be excreted in the form of urea, which requires energy in its conversion. Lower levels of protein in the diet leave extra energy, which can be partitioned to the cow’s condition at the cost of a low peak yield, which is returned with interest due to a flatter lactation curve later on. The use of controlled-release protein technologies (such as Optigen® from Alltech) can supply the rumen with a balanced form of protein and thus reduce overall protein consumption.

Fibre

The neutral detergent fibre (NDF) content of the total ration should lie between 30–38 per cent, with 75 per cent coming from forage. However, some forages may be too finely chopped or processed (e.g., precision chop pit silage, maize silage) to act as a true forage or roughage in the rumen. Total mixed rations should contain adequate amounts of long structural fibre to improve cud chewing.

All this information holds through in grazing-based systems, where the objective is to maximise the growth and utilisation of grass. Based on demand, which is driven by stocking rate, cow type, yield, weather and growth rates, occasionally there is a need to buffer feed or supplementary feed. The primary key in this situation is to look after the DMI of the cow, using concentrates and as much home-grown forages as possible. To avoid feed wastage, the efficiency of this feed and the grazed grass will be increased by feeding through a properly mixed TMR. This will also be key in keeping costs down and looking after rumen health.

Minerals

The importance of minerals in the diet of cows during early lactation should not be underestimated. Feeding an excellent, organic-based mineral post calving, when the immune system tends to be compromised, quickly builds the cow’s body reserves of essential trace elements. This in turn reduces the risk of metabolic issues in lactation. The use of organic-based minerals has been shown to increase margins by €50 per cow, based on the following results:

Additives can and should be used to allow the rumen to cope with sudden changes and the increased utilisation of feeds. Yeast-based products, such as Yea-Sacc® from Alltech, have been shown to aid in overcoming excessive loss of body condition and subsequent fertility problems. In grass-based trials, Yea-Sacc created a more stable rumen pH, which allows for improved feed and grass utilisation, meaning that fewer body fat reserves were mobilised and the cows retained better body conditions.

Silage quality

Although nutrition, BCS and minerals dominate discussion around early lactation, the foundation of all three is silage quality. In spring calving systems especially, silage is the main forage fed through the dry period and into early lactation. If quality is compromised, every other management decision becomes more difficult and more expensive to correct.Now is the time to influence silage quality for winter 2026–27. Once the crop is in the pit, the opportunity is gone. High-DMD silage does not happen by accident; it is the result of decisions made in the coming weeks around grassland management, cutting date and harvest discipline.

The single biggest driver of silage quality is cutting date. Delaying harvest by even one week can reduce DMD by three-to-four units as grass heads out and stem increases. Target leafy swards at the correct growth stage rather than chasing bulk. Heavy covers may look impressive but usually come at the expense of digestibility. Prioritise first-cut timing now: walk silage ground, monitor growth stage and have a clear trigger date agreed with your contractor.

Sward quality also matters. Fields with high perennial ryegrass content and good reseeding history will outperform older, stemmier swards. Identify underperforming paddocks now and earmark them for reseeding after first cut if necessary. Fertiliser strategy is equally important; apply adequate nitrogen to drive yield, but respect closing dates to avoid excess nitrates and poor fermentation.

High-quality silage can support intake and underpin performance next spring. But its success is determined in the next few months. The question is not what silage quality you want next winter; it is what you are doing now to achieve it.

Summary

As the cow settles into lactation, her appetite has fully recovered post-calving and she is on course to hit peak milk yield. In order to maintain a steady lactation and a successful breeding, it is vital that there are no restrictions in DMI. At regular intervals, it is key to review changes in milk protein, milk yield and BCS, and to consider whether there is an energy deficit or a requirement for supplementation at grass.

It is important to talk to a nutritionist if your system or ingredients have changed somewhat recently, if you are unsure about your current diet, or if you are experiencing any metabolic challenges. These are all very addressable issues, but if left unattended can create more deep-rooted issues.