TIME4SILAGING – Top Tips On Making Quality Silage

Top tips on making quality silage

With the cost of bought-in feed soaring, homegrown silage is an obvious choice to reduce reliance on purchased feedstock to meet target milk yields. However, it’s essential that the silage quality is optimised through multiple factors including calculated fertiliser use and considered cut timings. Make sure you’re informed ahead of this silage season by reading our top tips below:

Use soil analysis to inform inputs

To optimise grass growth and quality, it’s recommended that soil nutrient tests are carried out and analysed before adding inputs to silage fields.

Soil pH and lime status affect how well nitrogen is utilised by the sward so the results can be used to make sure the right input is applied at the right time.

Nitrogen application needs to correlate with the timing of the first cut and with subsequent cuts during the season. Aim to apply nitrogen at least 50 days before the expected cutting time to ensure full crop utilisation. It should also be applied at a rate that is adequate for grass growth but not so high that it’s wasted. Bear in mind that grass silage will take up to an average of 2.5kg/ha/day.

Pre-cut grass testing is key

 Due to variations in weather and growing conditions year on year and regionally, it’s important not to base cutting decisions solely on the previous year’s harvest date. Instead, take weekly grass samples, starting around three weeks before the grass is expected to be ready.

Grass sample reports will provide details of the nutrient composition of swards, specifically:

  • Neutral detergent fibre (NDF)
  • Dry matter (DM)
  • Free nitrate levels
  • Protein levels
  • Sugar content

Taking samples at least every week will indicate how the levels change which will inform the optimum cutting time to maximise forage quality and fibre digestibility. Pre-cut testing should continue to be carried out until at least the third cut to determine the cutting time.

Farmers in Cumbria can keep an eye on the weekly grass monitor reports posted on our social media channels for an overview of how the grass is changing throughout the silage season, which will also help to inform decision making.

 On-farm specialists can take samples and send them for laboratory analysis, or they can provide bags for samples to be taken. Check out our video below on how to take a grass sample:

Critical cut timings

Milder weather over winter or in early spring can bring the optimum first cutting date forward and conversely, colder weather conditions can delay it. Decisions on when to cut grass for silage should continue to be guided by pre-cut sampling results.

Silage should be cut when the NDF is between 38% and 42%. A rise in NDF of around 5% above target level can lead to a reduction in metabolisable energy (ME) of up to 1.6 MJ per Kg/DM in the silage.

If grass is cut at the optimal NDF level, energy levels in the silage will typically be higher, which will reduce the amount of bought-in feed required to meet energy requirements for milk production. The correct NDF level is also needed for good rumen function as levels exceeding the target can slow digestion and reduce intakes, impacting milk yields.

Pre-cut grass testing targets[1][2]

Parameter Target
Sugars (%) Minimum 3% in fresh weight (10% in DM)
Free nitrates (DM) >1,000mg/kg in fresh weight
NDF (% DM) 38-42%
DM (%) 18% at mowing

30% for clamping

35-45% for baling

[1] Take control of silage quality by pre-cut grass testing | Lallemand (lallemandanimalnutrition.com)

[2] 4 tips to get timing of grass silage cutting right – Farmers Weekly (fwi.co.uk)

Top tip:  If the free nitrate level is too high then, even if the NDF has reached the right stage for cutting, hold off cutting for a short while to avoid a negative impact on the fermentation process.

Consider the number of cuts

The number of cuts is very specific to each farm and its aim for quality and yield, so a multi-cut system may not be suitable for all farms. Think about the farms’ overall objectives, milk contract, silage plan, field locations and length of ley when considering how many cuts to take.

It can be tricky to get the nutrient balance right throughout the season but keep in mind that silage making and fertiliser programmes should always match the grass varieties on-farm and the desired number of cuts.

If you require assistance before or during silaging this year, contact your local on-farm specialist.

The Benefits Of Alfalfa For Livestock Species

The benefits of alfalfa for livestock species

Alfalfa is a commonly used ingredient in feeds for a wide variety of species including livestock, horses and pets such as rabbits. Whilst Dengie specialise in equine nutrition, their alfalfa based feeds are widely used for other livestock species. Here they share some of the key benefits of using alfalfa for other animals.

Alfalfa for Chickens

There are various ways that alfalfa can be of benefit to chickens. Highly compressed bales are used in commercial situations for hens to peck at to help alleviate stress. Any alfalfa they consume provides fibre for digestive health as well as a source of bio-available minerals.

Alfalfa is also used as a natural colourant in feeds for chickens to help create darker orange yolks. In studies using a concentrated alfalfa extract fed to hens, there was found to be 7 times more carotene in the eggs compared to those not supplemented with the extract.

Age takes its toll on the health of the chicken’s digestive tract. Increasing amounts of damage and the effects of high starch diets reduce the size of the villi and so reduce absorption rates of minerals and other nutrients. The demand for volatile fatty acids for the repair of the intestinal wall increases leaving less available to repair other areas such as the liver cells. These factors adversely affect the production of eggs and egg shell formation. It is therefore advisable to ensure sufficient fibre is included in the chicken’s diet. Although the oil content of alfalfa is low, what it does contain is higher in omega 3 than omega 6 which is in direct contrast to cereals. Alfalfa is often included to help improve the overall omega 3 profile of layers feeds.

Alfalfa for Dairy Cows

A recently published study showed that even pasture fed cows are short of beta carotene at some points in the breeding cycle. Researchers measured vitamin E and beta-carotene status of dairy cows from Belgium, Germany, Iberia and The Netherlands. These countries were selected to reflect differences in climate, forage type and feeding systems. The Netherlands was chosen because of the proportion of grazing dairy farms with high milk yield. Germany was selected as total mixed rations are commonly used there and Iberia was chosen because of its hotter climate, different forage bases, and a blend of non-grazing and grazing systems

Of all sampled cows, 44% were deficient in beta-carotene, meaning that their blood concentration was below 3.5 mg/l; the minimum recommended. Beta-carotene acts as an antioxidant for oocyte cells, while vitamin A which is produced from beta carotene, influences follicle development. The study showed that the 4 weeks around calving seemed to be a critical period for dairy cows to maintain their beta-carotene blood levels to support their health.

Poor forages which are a particular issue in hotter, drier climates such as Spain, had much lower levels of beta carotene and that was reflected in the cow’s status too. This principle can be applied to poor quality forages in the UK generally but even more so if longer periods of drier weather are experienced in the summer months such as happened in 2018. Although the beta carotene content of forage varies greatly due to numerous factors, green leafy materials such as alfalfa contain a lot more beta-carotene than alternatives such as cereals. This study provides the rationale for the inclusion of alfalfa in the rations of dairy cows at key times for those kept at pasture but more routinely for those off grass or on predominantly cereal based rations.

 Alfalfa for Sheep

When sheep are kept on smallholdings they are usually produced extensively for slow-grown meat with better taste and nutrition or to produce wool. Breeders may also be preparing their stock for showing or to sell as breeding stock and so often have pedigree or rare breeds. With all of these scenarios, putting better quality feedstuffs in, means getting more out.

Alfalfa for meat quality

Studies have shown that animals reared on forages such as alfalfa have better fatty acid profiles in their meat. This is because cereals are higher in omega 6 whereas forages contain a higher ratio of omega 3. It should be noted that forages are not high in oil but what they do contain is better quality than in cereals. When we consume the meat from animals reared on forage-based systems, we are getting the benefits of more omega 3 in our diets.

Alfalfa for wool and hoof quality 

Tissues such as wool and hoof horn contain keratin which is made up of amino acids or protein. Alfalfa is abundant in amino acids and is also a great source of highly bioavailable minerals such as calcium and sulphur which are known to help create strong hoof tissue. Whilst finer wool is produced from sheep in nutritionally deprived areas, too little nutrition can cause serious health issues and so it is important to strike a balance. Feeding sufficient but not too much is key.

How to include alfalfa in the ration 

250 grams per head per day will help to provide quality protein and other essential nutrients and is a practical level to feed to most sheep. If it is used to replace some of the cereal based feeds it also helps to reduce the risk of acidosis. When forage quality is poor, pregnant ewes are at greater risk of twin lamb disease and so adding up to 0.5kg per head per day to the ration can be beneficial. When ewes are heavily pregnant they can start to eat less as the lambs take up more space. Making every mouthful count helps to ensure nutrient requirements are met and so using better quality forages such as alfalfa becomes even more important. Adding some alfalfa 2 to 3 weeks before birth is usually beneficial.

Alfalfa is abundant in calcium and ewe’s milk is higher in calcium than cow’s milk. Supplying calcium in the ration is important to ensure the ewe doesn’t deplete her own reserves in order to pass the calcium on in her milk. Adding 0.25 to 0.5kg per head per day to milking sheep is our recommendation.

Alfalfa for Goats

Using higher quality forages that can contribute towards the animals’s fibre requirement and provide energy, protein and micro nutrients at the same time means less reliance on cereals which can help to keep costs down. There are other benefits for the health of the digestive tract too as it creates a less acidic rumen helping to maintain an environment in which microorganisms can flourish. This faciliates efficient fibre digestion and an healthy immune process.

Alfalfa is naturally abundant in calcium at about 1.5% as fed. A number of factors can increase a goats calcium requirement including genetic selection for faster growth rates and higher milk production and rapidly growing pasture that results in diluted calcium levels in the grass. Using straight cereals that are energy dense but low in calcium can disrupt the calcium to phosphorous ratios in the total diet if additional calcium isn’t provided. The source of calcium is also important as inorganic mineral sources such as limestone are less bioavailable than plant sources.

A mature dairy doe of 50kgs bodyweight yielding up to 1.5kgs approx would require 6g of calcium per day and a crude protein of about 190g per day. 1kgs of Alfalfa would provide 15g calcium and 140g of protein.

Vitamin D is closely connected to calcium status in the goat as it facilitates calcium absorption across the intestine wall. Known as the sunshine vitamin, vitamin D is formed by ultraviolet irradiation of plant material or the animal’s skin. You may already be aware that barn kept animals require supplemental vitamin D but if alternative forages such as straw are making a greater contribution to the animal’s requirements for fibre, the vitamin D intake is likely to be lower as straw contains less vitamin D than alfalfa or grass forages. Just adding some alfalfa to the ration will increase vitamin D intake.

Alfalfa for the Alpaca

There are similarities between the digestive system of the alpaca and the ruminant including the ability to eructate and chew the cud. However, the alpaca stomach only has three compartments compared to four in ruminants, which means that alpacas are often classed as pseudo-ruminants.

The first two compartments are basically fermentation chambers where simple carbohydrates such as sugars and starch and more complex carbohydrates such as fibre are broken down by a microbial population to produce volatile fatty acids (VFAs) which can be used as an energy source by the host animal. In contrast to ruminants, the first compartment of the stomach is not lined with papillae but with gastric pits that produce digestive enzymes and buffers to aid microbial fermentation. The third compartment, also referred to as the true stomach, is where enzymes and acids are produced for digestion of feed.

Fibre is fermented relatively slowly with highly lignified (woody) feeds such as straw, taking several days to break down. In contrast, sugars and starch are fermented very rapidly resulting in a sudden increase in VFAs, which increases the acidity in the stomach. This is known as acidosis and can impair the efficiency of, or kill certain beneficial bacteria in the stomach. The effect of this on the alpaca can be very serious ranging from loss of appetite to diarrhoea and in severe cases death.

The nutrient requirements for camelids including alpacas are largely unknown as limited research has been conducted. Most estimates are based on extrapolations for the nutrient requirements of ruminants particularly goats and sheep. Alpacas weigh between 45kg-80kg and can consume between 1.8%-2% dry matter of their bodyweight daily. For an alpaca that weighs 63kg this would equate to between 1.13kg-1.26kg dry matter daily. Alpacas have evolved to eat a fibre-based diet and their digestive system is most efficient and healthy when their ration is based on fibre.

The most common feeding strategy for alpacas is grazing supplemented with additional hay and at times of higher energy demand such as the winter months, during pregnancy and lactation, additional cereal concentrate rations are provided. Although cereal concentrates provide the extra calories needed, they may cause problems within the digestive system including gastric ulcers, colic and acidosis. Alternatives to using cereals include alfalfa, a quality source of fibre that is very low in starch.

Alfalfa is a member of the legume family that also includes soya, peas and beans. Legumes are known for being a good source of quality protein and alfalfa is no exception. It is also rich in naturally occurring vitamins and minerals but contains very little starch so is useful for avoiding digestive problems.

Dengie is the largest producer of alfalfa-based feeds in the UK and although they are marketed primarily for horses, they can and are used for a wide range of other animals including camelids. The Alfa-A range is based on pure alfalfa with different coatings whereas the Hi-Fi range combines alfalfa with other fibre sources such as straw and grass.

Generally, the Hi-Fi range with its lower energy values, are ideal for alpacas that maintain their weight with ease. For alpacas with increased energy requirements such as those that are kept for breeding, Alfa-A Original or Alfa-A Lite may be more appropriate. Alfalfa Pellets are also suitable for alpacas and are particularly convenient for feeding outside.

dengie alfa a range

Dengie is the largest producer of alfalfa-based feeds in the UK and although they are marketed primarily for horses, they can and are used for a wide range of other animals including camelids. The Alfa-A range is based on pure alfalfa with different coatings whereas the Hi-Fi range combines alfalfa with other fibre sources such as straw and grass.

Generally, the Hi-Fi range with its lower energy values, are ideal for alpacas that maintain their weight with ease. For alpacas with increased energy requirements such as those that are kept for breeding, Alfa-A Original or Alfa-A Lite may be more appropriate. Alfalfa Pellets are also suitable for alpacas and are particularly convenient for feeding outside.