No restrictions

Following on from such extreme weather events in January, farmers are feeling great relief with the (slightly) more settled weather of late. The memories of last summer’s slow growth rates, coupled with winter forage shortages are fading as the grazing season gets going. Total farm covers are good but wide-ranging, anywhere from 700kg to 1,300kg of dry matter (DM) per hectare; while 10 per cent to 40 per cent more grass is available compared to other years, and we can capitalise on this.

Stress free

We are also in the midst of the calving season, and it is worth remembering that up to 80 per cent of all metabolic problems that a dairy cow can experience occur in the transition period. This is a staggering statistic with knock-on effects for the breeding season. A lot of farmers have easy calvings with minimal intervention or metabolic issues. This gives the dairy cow a fantastic start to her lactation and breeding season. Of course, other cows and farms will struggle. A dairy cow goes through two major stress points in her lifetime: weaning and calving. We must make life for our cows as stress free as possible.

DM intake (DMI) is vital in early lactation. While a cow will not reach peak DMI until eight to 10 weeks post calving, she reaches peak milk yield around six to eight weeks post calving. Cows will lose body condition in early lactation because of this, but it should be minimised to <0.5 of a body condition unit (4 per cent of body weight). This can be done by pushing DMI and feeding the correct diet in the correct proportions (grass, silage, concentrate) based on your cow and milk yield.

Cows can mask issues in the first six weeks or so of calving. They can produce good milk yields with high solids, but they are ‘milking off their back’ losing body condition score, as they do. Whether the diet is adequately fuelling the cow will become clear in the weeks after this, where loss of condition will really become apparent, and production can suffer. To avoid this, we must make sure the cow is getting the best nutrition from her feed. Several factors play a role in feed efficiency, but rumen health is one of the most important.

Grazing

The focus of all grazing plans should be on achieving and maintaining high-quality grass all year round. This is done simply by meeting the targeted pre- and post-grazing covers of grass which will vary from farm to farm depending on stocking rate, growth rates and season. The initial target of aiming for 30 per cent of the farm grazed by the end of February is underway on many farms at various levels again depending on the number of cows calved, land type, weather, etc.

We also must not lose sight of the fact that we are feeding cows, who have just calved, and they are trying to double their intake over the next few weeks. We need to support this where we can and maximise it with the available grass, silage and concentrate. Cows will need to work hard over the next few weeks and should be constantly either eating, cud chewing or milking. We need to maximise the amount of grazed grass they can eat, avoiding trying to force cows <4cm, but also not be afraid to supplement the cow when she needs this. In the absence of this body condition, milk solids and fertility will suffer, with milk yield being the last to drop. Depending on silage quality, cows will need approximately 0.33kg of concentrate per kilogramme of milk when in full time or out for a few hours, reducing to 0.22kg once they are out by day remembering that if we run short of grass or weather and conditions are bad, we need to revert to full time allocation again.

Buffer feeding

The key with supplementary feeding (buffer feeding) is to always be measuring and monitoring. If you know how much grass you have, it is easy to allocate the remaining supplementary feeding necessary. We want to allocate the correct levels and not substitute. For instance, if we offer 12kg of grass DM and 12kg of supplement DM and the cows can only eat 20kg, then this is an issue. While some farms can give many reasons not to budget grass, we need at minimum to be able to measure it and this can be as simple as scoring a cover based on vision. If we can see the cow is entering a hectare paddock of 1,400kg DM and you have 100 cows you are allocating 14kg of grass. Only then can you make an informed decision on your supplementation level.

Paddock/field size should also be a focus as cow numbers/stocking rate has increased over the years since quota abolition. Having an area large enough to fully feed the cows over a 12-, 24- or 36-hour period is important, especially in large herds, as this can manifest itself as underfeeding. While this might not be fully noticed, it is restricting cows by 1kg-2kg of DM.

Supplements will come in a few different forms either through a mixer wagon, silage on its own, or via the parlour. Your amounts and when to feed these will be determined by your stocking rate, yield/cow type and weather to name but a few. We always try to eliminate silage as early as possible in the diet as it is a poorer feed compared to grazed grass but if the cow is lacking intake, then always remember that a kilogramme of something is better than a kilogramme of nothing.

The cow and, more importantly, the cow's rumen will go through a lot of change over the early lactation period. Doubling its intake over a few weeks, dealing with acidic silage at 12 per cent crude protein, to lush grass of 20-30 per cent protein varying in DM by 10 per cent daily, to changing concentrate levels to having to deal with the ever-changing weather. This can impact cows through reducing milk and solids yield and sometimes even sickness. While cows can deal with a lot of it, it is important to support her and her rumen in all of this. A live yeast is a well-known way to stabilise the rumen to help with the peaks and troughs and be able to take the punches when they arrive better. During this time, it should be customary practice when purchasing feed from feed companies or coops to include a live yeast.

It is a busy time of year and hard to keep on top of the many changing events, so it is important to speak to a nutritionist if you feel you have experienced these very solvable issues now or in the past.

Vitamins and cal-mag

As the early-lactation cow increases her DMI from grass and receives less from supplementary feeding, we must ensure that the correct levels of minerals and cal-mag are still in the diet. Ideally, the feeding rate of the parlour concentrates should have the correct pro-rata levels of mineral. As the level of concentrates decreases in the parlour, it is worthwhile to manually weigh what is in a ‘pull’ to ensure correct calibration.

The integral role that minerals play in the resumption of cyclicity, and the successful breeding of the mid-lactation cow cannot be overlooked. Going into breeding, we want a cow that has a healthy immune system and displays a strong heat. Deficiencies in certain trace minerals can be related to infertility. For example, anoestrous behaviour and silent heats in the herd are linked to deficiencies in copper and manganese. Optimal levels of organic selenium have reduced incidences of metritis and reduced services per conception significantly (Agovino, 2011). A proportion of the mineral should be supplied in an organic form, such as that found in Bioplex and Sel-Plex. The mineral is then more bioavailable for absorption by the cow, and there are fewer interactions with antagonists.

Summary

As the cow settles into lactation, her appetite has fully recovered post calving, and she is on course to hit peak milk yield. 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 consider whether there is an energy deficit or a requirement for supplementation at grass.