Feeding and managing your dairy herd and youngstock this autumn and winter

Summer 2018 has been a difficult season for grass growth, resulting in most farmers having less silage in store for next winter than they’d like, with many having to tap into winter stocks already to make up for the lack of grazing.

Technical manager for Phileo Lesaffre Animal Care in the UK and Ireland and CowSignals® master trainer, James Ambrose, details some nutritional and management areas that dairy farmers need to be mindful of this autumn and winter to help manage the challenges that have arisen from the dry summer.

When planning for feeding over autumn and winter, it is essential to determine how much forage you currently have. Measure silage clamps and count the number of silage bales in the yard and see how much good-quality straw you can get hold of.

Contact your local feed advisor to assist you with measuring silage pits and estimating silage quantity and preparing autumn and winter-feeding plans for your farm if needed.

To make up for current deficits in silage stocks, growing a third cut of silage will be critical for many farms (budget on yields of 6t/ac when doing your budget).

If this is still not enough, straw-based diets can form a significant portion of winter diets in these circumstances if sufficient straw is available.

Alternative sources of forage for the autumn are fast-growing grasses or forage rape or kale that have been planted in stubbles. Depending on the individual crop, these can be used for baling, pitting or extending the grazing season.

Finishing stock and youngstock may need to be housed now in order to facilitate the growing of a third cut in the fields. Housed youngstock will do well on a straw-based diet, with a mix of concentrates and a minimal amount of silage so long as it is mixed and fed correctly.

Regardless of whether these animals need to be housed or not now, straw and concentrate-based diets for youngstock can significantly save on silage demand through the winter, while still maintaining growth rates; high-straw diets also work well for dry cows, further reducing the demand on silage.

Things to remember when feeding straw-based diets:
  • Have your diet feeder serviced over the coming months if it has not been serviced already and ensure that all knives are sharp and installed properly;
  • If a diet feeder is incapable of chopping straw, then straw can be pre-chopped using a straw chopper or forage harvester. Straw should be ideally chopped to 2-4in long (muzzle width of the animal);
  • Water may need to be added to the diet feeder mix in order to keep the mix moist and minimise sorting if drier silages are being fed with straw and concentrate. Aim for 45% dry matter in the overall mix;
  • Adding molasses to drier diets will aid against sorting and increase palatability, but be careful not to overfeed it as it is high in sugar.

High dry matter digestible (DMD) grass silage, wholecrop cereals and maize silage should be prioritised for cows post-calving in the spring with lower DMD grass silage being fed to dry cows once they are in the correct condition score at drying off.

However, if a fodder budget shows a serious deficit and this is not filled by winter, a proportion of the dry cow and youngstock diets can be supplemented with either wholecrop or maize silage, along with grass silage, and balanced accordingly.

Be sure to get your forage analysed. Do not ignore carrying out this task this year, as knowing the quality of forage in the yard is as important as having quantity in the yard.

If you simply haven’t got enough silage and straw, and can’t get more, then the next step is to decide how many animals will be retained through the winter.

Cull cows that are not in-calf, any that are lame, have high somatic cell count and repeat mastitis offenders. This will optimise overall herd health and improve returns, whilst reducing forage requirements and feed costs.

Having done all of this, if a major deficit still exists, selling off productive milking cows or youngstock will be a last resort.

Current recommendations for dairy herds

While looking ahead to the winter is very important to do right now, the current priority for dairy farmers will be feeding milking cows and maintaining milk solids production.

It is vitally important that everything possible is done to maintain persistency of production through the autumn and into the early winter in order to maintain a steady revenue stream.

A target of a drop off in milk solids yield of 2.5% per week or 10% per month is a good benchmark to use. In practice, this means that a cow that was yielding 25L/day in mid-August should be yielding 22.5L/day by mid-September.

Grass growth has increased in recent weeks and covers have bulked up and, as a result, the pressure on supplementary buffer feeding of silage and soya hulls has decreased somewhat.

However, the reality is that cows still require a substantial amount of concentrate through the milking parlour over the coming weeks so as to manage the grass demand per hectare relative to growth rates and to allow grass covers to be built up for grazing during the back end.

For example, if a farm is stocked at 3.25 cows per hectare on the milking platform and a farmer allocates 14.5kg/cow/day of grass dry matter with a predicted 90% utilisation, the demand is almost 48kg/ha/day (dry matter).

If growth rates of 60kg/ha/day are achieved over the coming weeks, the average farm cover could potentially be increased by 250kg/ha within three weeks. This will require an 8kg/day parlour feeding rate for a 620kg cow producing 1.9kg of milk solids per day (25L at 4.1% fat & 3.45% protein).

Depending on each individual farm’s circumstances, and what the current average farm cover is, it may be possible to achieve the recommended average farm cover of 1,100kg/ha by mid-September by continuing to feed 8kg of concentrate through the parlour and limiting grass demand to approximately 48kg/ha/day.

It is a good calculation to do if you have not done so already. If grass growth is lower or if the stocking rate is higher on the milking platform, then silage, soya hulls or both will probably need to be kept in the diet until the desired average farm cover is achieved.

Keeping an eye on the costs of production, in particular income over feed costs, will be important over the coming months; therefore maintaining persistency of production will be so critical.

Managing rumen function and avoiding issues with acidosis

Be extremely alert to the risk of acidosis when feeding higher levels of concentrate this autumn, particularly over the coming weeks when lush and leafy grass swards come back into the diet.

Sub-acute rumen acidosis (SARA) will reduce intakes, milk solids yield and fertility and can result in inflammation and lameness. In its clinical form, it can kill animals.

The following tips will help you best manage the risk of acidosis in your herd:
  • Feed a maximum of 8kg of concentrate through the parlour. If more is required, it should be at a head feed in collecting yards. Do not feed more that 50% concentrate in total in the diet;
  • Make changes to the diet slowly and feed concentrates as consistently as possible. Feeding higher starch rations because of higher cereal levels in feed will require careful feed management and increased attention to detail. Work with your feed advisor on purchasing the best compound feed formulation for your herd’s individual circumstances;
  • Observe cow signals for signs of acidosis, such as loose dung with gas bubbles and undigested fibres and grains visible. Other warning signs include: poor rumen fill and empty looking cows; cud balls in collecting yards; poor cudding rates; and cows losing body condition;
  • Feeding Actisaf live yeast will significantly reduce the risk of acidosis this autumn and simultaneously increase the feed conversion efficiency of your herd, helping them to produce more milk solids from the same amount of feed.

Actisaf is the only live yeast scientifically proven to reduce lactic acid levels in the rumen (which accumulates and causes acidosis) and published research in the Journal of Dairy Science has shown it to lower lactic acid levels to a greater extent than sodium bicarbonate (bread soda).

It also increases fibre digestion in the rumen, unlocking more energy from silages and increasing herd performance.

Actisaf live yeast can be included in your compound feed, blends and coarse ration by your local feed mill at a rate of 1kg/t for a 6-8kg feed rate, costing €10/t. For farmers using diet feeders, it can be included via a 25kg farm pack.

For further information, contact Phileo Lesaffre Animal Care at: 061-708099 (Ireland) or at: 028-93343900 (Northern Ireland). Click here for more information