By Seamus Millea InTouch Feeding Specialist

Spring is upon us, and many farms are in the middle of calving at this stage. As this is a stressful period for both the farmer and the cows, it is easy to take your eye off the ball when it comes to balancing the herd’s diet in early lactation.

In the first few weeks after calving, cows will physically struggle to eat enough to match their energy requirements. This will put the cow in a negative energy balance (NEB). The extra energy required to match the cow’s milk output will come from her body reserves, and she will start to lose condition.

This happens on all farms, but it is important not to lose excessive body condition, as doing so has been shown to be linked to negative fertility performance in the herd.

This can be exacerbated by cows suffering from a metabolic issue, so it is important to get it right, as 80% of metabolic issues happen during the transition period (i.e., three weeks pre-calving to three weeks post-calving).

Seamus Millea

Body condition score

We need to take a look back at the dry cow period as we transition into the milking cow diet. The aim of a successful dry cow diet is to have the cow calving down in a body condition score (BCS) of 3–3.25, a successful calving event and for the cow to go back in calf as quickly as possible.

The KEENAN dry cow program focuses on achieving this with a controlled-energy, high-fibre diet, allowing the cow to hold her condition for the dry period and transition more quickly onto the milking cow diet.

The amount of condition the cow will lose in early lactation will have a significant impact on her milk yield performance for the year ahead. Ideally, we do not want to lose more than 0.5 BCS in the first six weeks after calving; this would equate to a loss of around 25kg in your typical 600kg Friesian cow, or 4% of her mature body weight.

Nutrition

Dry matter intake (DMI) will have a big impact on early lactation, as the cows will not reach their peak DMI until two to four weeks after they reach their peak milk yield. The impact of this is minimised by feeding the correct proportion of each ingredient and balancing the diet.

As a cow has the ability to produce a few extra litres of milk from her body reserves, it can be hard to determine how well your diet is working. Looking at the condition of the cow six weeks post-calving will indicate whether enough energy was provided from the diet or whether the cow was using her own condition to produce milk.

Elevating the fat and protein levels in this period can mislead you into thinking that enough energy is being provided, but it is not always a true reflection of the diet.

Silage sampling is important, as it will make up 50% of the in-full-time diets on most farms in a spring-calving system. Most silage samples will give an indication of the potential intake of the forage.

This will vary between the breeds and sizes of cows, but it will correlate to the amount of fibre in the forage (NDF), which will be the limiting factor when it comes to how much the cow can physically eat.

In many cases, cows are often expected to eat too much forage and end up losing more condition than they need to, as the diet is not energy-dense enough. Table 1 below can be used as a guide when calculating the amount of concentrates we need to match the milk yield of the cows on a 65 DMD silage.

The important thing to note is that every farm is different, but the same principle can be applied to your farm’s individual requirements depending on the cow breed, size, peak milk yield and quality of the forages, etc.

The protein level of the diet will be a key driver of the milk yield potential. Producing more milk and not matching the energy in the diet will lead to increased body condition losses and poorer conception rates in the herd.

We can also look at ways to try to increase the cows’ DMI in early lactation. A freshly calved cow will likely only eat around half of her required intake in the first week post-calving.

This is the critical period in which we need to fill the energy gap, and this can be done by offering the cows an energy-dense diet.KEENAN customers would typically use some straw and concentrates in the dry-cow diet, which will increase the intake potential post-calving and help the cow transition to a high-energy diet.

The KEENAN feeder gives you the ability do a total mixed ration (TMR), and it will allow you to incorporate a second forage source, like maize silage, which has been used to great effect on many farms, as it can increase DMI by up to 15%. The quality and consistency of the mix is vital during this period.

The InTouch nutrition team can monitor each load, as the information is saved on a cloud-based system using the KEENAN controller. This will allow the farmer and the InTouch feeding specialist to track the DMI and feed conversion efficiency (FCE) and make ration changes based on this information.

The InTouch team can also use the PastureBase grass-measuring software with the farmer so they can make informed decisions on increasing or decreasing buffers, depending on the amount of grass available on the farm.

Getting grass into the diet will be a priority on most farms over the next month, with concentrates and protein, in particular, increasing in price since the start of the year.

The aim would be to do this without compromising DMI and thereby undoing all the hard work you have put in up to this point. If you are looking to let the cows out for a few hours, it is important to know exactly how much they have available in the paddock so you can adjust the forage-based diet when they are in by night.

A 150-cow herd going into a cover of 1,000kg of dry matter (DM) per hectare will offer 8kg DM/cow. If utilisation is 90%, this will be closer to 7kg of grass being consumed.

Wet weather has a negative impact on grass utilisation, and DMI will drop 0.4kg for every 1% drop in grass DM under 18%. Taking these considerations in hand and keeping an eye on your post-grazing residuals will go a long way toward helping you decide how much supplement is required.

Understanding the difference between what the cow is physically eating and what she is utilising is also important. If we can increase the amount of forage being utilised in the rumen, then we will release more energy for the cow to use and increase the feed efficiency of the diet.

Incorporating a live yeast like Yea-Sacc will improve rumen function, help stabilise the pH and lead to a diminished immobilisation of the cow’s body reserves.

Management tips:

  1. Allow one feed space per cow post-calving;
  2. Give freshly calved animals, especially heifers, at least 48 hours to increase their intake in a low-stocking environment before being let out to grass;
  3. Keep the face of the pit clean to avoid heating and mouldy silage;
  4. Keep the feed at the barrier fresh, palatable and free from heating;
  5. Total mixed rations should be about 40–45% dry matter, so water might need to be added to some dry silage;
  6. Consistency is important, especially in a TMR diet, to avoid sorting of the mix;
  7. Measure your grass — if it’s not measured, it’s not managed;
  8. Water supply is very important. Cows need good access to clean water, which is sometimes taken for granted.