Hay remains a key strategy to get your animals through the winter. Farmers have several options, and if some basic pitfalls can be avoided, success can be achieved.
The strategy of using hay, foggage (standing hay) and silage to keep animals fed during winter in the summer rainfall areas, has long been part of cattle farming. The cost of making hay and silage is the same regardless of whether the quality is good or bad, so it makes sense to go for quality. Successful overwintering is all about feeding animals with high nutritional needs at a time when there is not enough nutrient value in the veld. Good quality and feed value are core principles in stored winter feed. It is not worth sacrificing quality for bulk, especially when doing this means the loss of nutritional value.
HAY
Hay is a key forage for feeding animals through the winter. And making good hay is not difficult, provided the basic haymaking rules are observed.
The quality of hay depends on the following:
■ The quality of the grass to be cut and baled. Legumes, such as lucerne and poor man’s lucerne, are popular choices because they make good quality hay. Grass has a lower nutritional value than legumes but there are grass species that make good quality hay. The most popular summer grasses used in haymaking are tef, Smuts finger grass, white buffalo grass, Rhodes grass and bristle grass. Winter grasses such as oats and rye grass may also by cut for hay. Soil types and rainfall will usually dictate the type of hay to be used.
■ Leaf-to-stem ratio
The more leafy the hay, the better its quality. Leaf-to-stem ratio, growth stage at mowing, cultivar type and the percentage of leaf lost between cutting and baling will all influence hay quality. The best time to mow grass is during active plant growth while the seed is still sheathed. Lucerne should be cut for hay at the 10% flowering stage. The problem is that the plant could be past the 10% flowering stage but not appear to be so because of insects feeding on the flowers. A better guide is to look at the new shoots that grow from the crown of the plant. As soon as these shoots appear, cut the lucerne. The farmer who waits too long to cut will pay for it by losing the next cycle of growth. In the case of poor man’s lucerne, cutting should start as soon as seed begins to fall.
■ Timing and techniques
Hay that is left on the land may be damaged by wind, leached by rain and suffer a breakdown of nutrients by overexposure to sunlight. It is best to cut, dry and bale on the same day. Thick-stemmed plants take longer to dry, so the hay should be aerated. Take weather into account and check forecasts before you schedule a date for mowing. In the case of lucerne, bale in the early morning when leaf loss is minimised by the dew.
■ Moisture content of plant material at baling
Moisture content should be between 10% and 20% to stop mould from forming. Mould can lead to animal mortalities caused by fungi that produce aflotoxins.
■ Soil fertility
The soil fertility of haylands drops with time because the crop is constantly taken off the land. This means there is no nutrient recycling like there is when livestock grazes a pasture and therefore from time to time the farmer will need to put fertiliser down. Take out the soil fertility guesswork by sending soil samples off for analysis so that fertilisation is on the mark.
■ Clean hay
Potentially good hay is often contaminated by weeds, so make sure haylands are weed-free when they are established. Good quality hay is green, leafy, contains minimal weeds, has a neutral smell (strange and pungent smells are not desirable) and is not mouldy. It is good practice to analyse the nutrient content of the hay. This will indicate whether the animals need supplements.
STANDING HAY
Standing hay, or foggage, is hay that is not cut but is left to stand on the land so that it can be directly grazed by the animals after it has frosted off. There are no cutting and baling costs. The disadvantage of standing hay is that the quality may be reduced. However, in most cases, this problem can be successfully overcome by feeding supplementary licks. Practices to get standing hay to a fair quality include the following:
■ Choosing the right crop
The best crops to foggage are those that keep their quality and palatability at a mature growth stage and after they have been frosted off. Grasses such as bristle grass, Smuts finger grass and maize are popular choices. Lucerne is also used.
■ When to foggage hay
Mature plant material has a poor leaf to stem ratio and the pasture should not be too advanced in its growth stage at frosting off. Plants that are still leafy when it starts to frost are ideal. For good results graze or mow the planted pasture at the end of February and leave it after that as standing hay.
■ Fertilising
As in the case of hay, it is best to send off a soil sample for analysis and then fertilise accordingly.
■ Foggaged lucerne
This high-value legume is gaining ground as a standing hay crop. Lucerne is associated with frothy bloat and prussic acid poisoning and is usually not considered a grazing crop. However, these problems are almost completely eliminated once the lucerne has been frosted off. Niel Schoombee and Jan Theron, farmers in the Middelburg district of the Eastern Cape, have grazed foggaged lucerne for many years. Niel discovered the value of lucerne as standing hay accidentally when his Dorper sheep went through a fence into a lucerne land and started grazing the lucerne that had been frosted off. He was pleasantly surprised when his sheep did not die.
These farmers recommend the following course of action: Leave the last cut of the season on the land to be frosted off. The lucerne should be at knee height when the first frosts arrive. The shorter the lucerne at the first frost, the less standing hay there will be and the less feed for the livestock.
Before the animals go in, the tops of the lucerne should be frosted white. At this stage the danger of bloat and prussic acid poisoning will be completely over. Initially, when it is cold and still frosting regularly, switch to alternate pastures. Later when it starts to get warmer and the lucerne begins to shoot, put the animals on a continuous grazing regime that keeps the lucerne as short as possible. Unless there is continuous grazing at this stage, the plants will grow taller than 5cm and the problems of bloat and prussic acid poisoning will recur. The weather will dictate when to stop grazing. In colder regions where there is still frost in October lucerne may be grazed until mid-October.
A carrying capacity of about 10 ewes/ha for 60 days is possible with dryland lucerne and one of 45 ewes/ha for 60 days with irrigated lucerne. The cultivars SA Standard and SA Select are recommended because both are relatively dormant in the winter. Avoid non-dormant lucerne cultivars. They do not frost off properly and can cause bloat or prussic acid poisoning.
SILAGE
Once the silage is in the pit, fermentation of the ensiled material takes place and sugar is converted to lactic acid by anaerobic microbes. Lactic acid lowers the silage pH, which acts as a preservative. Silage quality is determined by the following:
■ The sugar content of the crop
Most grain species can be ensiled but maize is the most popular choice and makes the best silage. Even lucerne and grass may be ensiled. A high sugar content means more lactic acid, fast-acting preservation and high-quality silage. If the sugar content of the crop is too low, additional sugars and bacteria (in the form of inoculants) must be added or there will not be enough lactic acid produced to preserve the silage properly.
■ Harvesting at the right moisture content
The ideal moisture content at ensiling is 60% to 70%. If the moisture content is too high, nutrients may be leached from the silage. Too much moisture may also lead to rotting during which micro organisms produce micotoxins. If the moisture is too low, fermentation is greatly reduced and the silage will be of a low quality.
■ Proper compaction
Extract as much air as possible to get optimal silage quality. The size of the plant material plays a role here and finer material is preferable. The recommended minimum compaction is 600kg/m3 . It is essential to seal the silage pit (or heap) properly to protect it from the air outside the pit. Long, narrow silage bunkers usually produce the best results.
■ When to cut silage
Top quality silage comes from ensiling the material at the right moisture and sugar content. In maize a rough guide is when the so-called milk line of the maize kernel is halfway to two thirds of the way up the outside of the kernel. The milk line separates the moist part of the kernel from the drier, firmer part.
■ Pit management
The best way is to take out just enough silage for one day. The silage face should be as straight as possible to minimise aerobic activity. An uneven face has greater surface exposure. A smooth, straight face ensures reduced exposure for the silage still in the pit. As soon as the silage is exposed to the air, the feed value is reduced and there may also be a danger of micotoxin production, which is deadly to animals. Once the silage has been taken out, the cutting face must be resealed. Silage of good quality has a slightly sour, fruity aroma. The hallmarks of poor silage are aromas that smell like rancid butter, ammonia, burnt sugar or tobacco.
There should be no watery effluent from silage when it is squeezed and no sign of mould of fungi. Recommended practice is to send a sample off to the lab for analysis.
Dr. Louis du Pisani is an independent agricultural consultant who works in the fields of cattle, veld and financial management. For more info, email Ldupisani@gmail.com.
