Focus on home-grown forage to cut farm input costs

Flock keepers have responded to the rising cost of inputs by increasing their reliance on home-grown forages. Independent sheep consultant, Kate Phillips, ran through the options in a webinar hosted by the National Sheep Association.

Sheep nutrition has a major influence on flock efficiency, alongside flock health and genetics, Mrs Phillips told webinar delegates. She outlined the costs associated with the main options for home-grown feedstuffs.

“Grazed grass is the cheapest at about 8p/kilogram dry matter and 0.55p per megajoule of energy, followed by high quality grass silage at 16p/kg/DM and 1.14p/MJ of energy. Home-produced barley will cost approximately 19p/kg/DM (1.41p/MJ of energy) and despite prices coming down slightly for this winter, concentrate feed is the most expensive at 41p/kg/DM (3.26p/MJ of energy).”

A 70kg ewe carrying twins has a daily maintenance energy requirement of about ten per cent of her bodyweight, plus 1.8MJ, making a total of 8.8 MJ/energy/day, she explained. It will double in late pregnancy and reach 3.5 times maintenance in early lactation.

“Meeting the ewe’s energy requirements is the most important factor, when calculating a pregnant ewe’s dietary needs,” stressed Mrs Phillips. “However, it must be considered against her potential dry matter intake, which varies according to stage of production.

“A 70kg ewe that is dry, post-weaning or in early-to-mid pregnancy, has a dry matter intake potential of about 1.5 per cent of her bodyweight, which is equal to 1.05kgsDM/day. In late pregnancy, the figure will rise to 1.40-1.75kgsDM/day and it will further increase to 2.45kgsDM/day in early lactation.

“When converted into an annual demand, the total for one ewe with two lambs adds up to almost 11,000 MJ of energy, which in turn is equivalent to about one tonne of an 11 MJ/kgDM grass, silage or forage crop feedstuff. Nevertheless, a figure for wastage will need to be factored in, when calculating requirements.”

The most efficient method of feeding is to move the sheep to the source of feed, she added. She advised against changing ewe diets in the first five weeks of pregnancy and any changes during other stages should be made gradually. It was also important to meet trace element requirements when feeding very limited amounts of compound feeds.

“Sheep fed on mainly forage-based diets may be at risk of trace element deficiencies, depending on soils and forage type,” she said. “Cobalt deficiency has been shown in trials to impair embryo development, while low selenium and vitamin E have been scientifically linked to an increase in embryo loss at implantation, as well as reduced immunity. In addition, a lack of iodine can cause stillbirths and poor lamb growth rates.”

Grass production can be monitored throughout the growing season using a sward stick or plate meter, she suggested.

“The measurements can be used to calculate grass dry matter production. The figures can be assessed in combination with GrassCheckGB, a collaborative industry project which offers online results of grass productivity on sites around the country in real time. This will help flock managers to identify any shortfalls in forage requirements and help with planning to fill any forage gaps.

“In recent years, we have commonly seen a dip in grass productivity in June due to hot, dry weather and this was the pattern for 2023, although there was a recovery in growth in the following three months. The energy and protein content of grass was relatively high in October at 10.8MJ/kgDM, with protein above 20 per cent.”

Grass alternatives

Herbal leys: potential to improve soil quality; reduce nitrogen use; improve drought tolerance and animal performance; lift dry matter yields. Can command payments including £382/hectare within the ‘GS4’ legume and herb-rich seed mix stewardship option. Trials have shown a potential reduction in wormer use. Species should be chosen to suit individual farm situations.

Red clover/Perennial ryegrass mixes: An excellent feed for ewes and finishing lambs. Opportunity to ‘grow’ protein, with the added benefit of nitrogen fixation. High intake potential, with little need for dietary supplementation. Drought tolerant. Historically, red clover has been associated with ewe fertility issues, but low oestrogen varieties are available. A recent Innovative Farmers trial showed that including some red clover in mixed swards (up to 37 per cent of red clover in the cut herbage) had no detrimental effect on ewe fertility on four trial farms.

Lucerne: A useful choice in dry regions, 22 per cent plus protein, 11 MJkg/DM. Ideal for rotational grazing for seven to ten days but will require six weeks’ rest. Salt should be made available. The sheep should be transitioned on to the crop carefully, to avoid the risk of bloat and red gut (intestinal torsion).

Brassicas: can provide dietary supplementation to grass, but poisoning can occur if excessive quantities are eaten in warm, overcast weather which follows a long, dry spell. Preventative measures include introducing the crop gradually, building up from an initial two-hour access period daily.

Fodder beet: One of the highest-yielding crops (14-20t/DM/ha). Use a palatable variety and transition on to the crop over several days. Allow 0.3 metres of linear fence per animal. A two-day shift is ideal for achieving a balance of bulb and leaf ingestion, balancing the hjgh sugar and water in the bulb to the high protein and minerals in the leaf.