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News > Herbal leys performing well on County Down farm


Herbal leys performing well on County Down farm

August 25, 2021

Farming outside of Strangford on the east coast of County Down, is organic beef and sheep farmer Dale Orr, who in the past four years has adopted the inclusion of herbal leys into his farming rotation.  The idea was first discussed with Dale’s CAFRE Beef and Sheep Adviser, Dominic Mason, at his local Sheep Business Development Group (BDG) meeting and has progressed from there with 75 acres now being grown on farm.  With the farm being operated organically the herbal leys with their deep roots, nitrogen fixing and lifting capabilities and anthelmintic properties fit into the system perfectly especially in recent years where many parts of the country have experienced drought type conditions.

Calving and lambing commences on the Orr farm at the start of March with 103 Hereford x suckler cows and 390 purebred Lleyn ewes with an additional 90 in lamb ewe lambs.  All the progeny from both the Beef and Sheep enterprises are finished on farm. Great emphasis is placed on maximising forage production, utilisation and overall livestock performance in an effort to increase farm profitability.

Herbal leys or multi species swards are a seed mixture of grasses, legumes and herbs.  The grasses contained within the mix contribute as the main supply of energy, the legumes that of protein and the herbs the main provider of minerals.  This mix ultimately brings a range of benefits, not only to the quality of the forage being produced but also benefits the health of the livestock as well as soil fertility/structure.  For instance some 3rd party on farm grazing trials have shown reduced faecal egg counts (FEC) on lambs which were grazed on swards containing herbs in the mix such as chicory due to the anthelmintic properties which it processes.  Ultimately, this reduced the need or frequency for worm dosing of stock grazed on these swards, allowed for an increase in daily live weight gain (DLWG) of the lambs and better milk production & body condition score (BCS) retention of the ewes throughout the season.

Due to plant diversity within a herbal ley sward and its dense leaf structure above the ground it naturally has the ability to capture more sunlight which in combination with its deeper rooting structure allows for better water & nutrient uptake and retention and subsequent growth, especially in drier more drought like conditions.  These attributes along with the nitrogen fixing capabilities of the legumes which can be as high as 150-200kg N/ha/year and nitrogen lifting capabilities of the herbs allows for in many cases greater growth during the summer months where temperatures are higher and soil moisture content lower.

AFBI research has shown that within grass and white clover swards approximately 120kg/N/ha can be fixed from clover.  To compare this with what is achievable from grass-only swards receiving nitrogen in the form of artificial fertiliser, you would need to apply 180kg/N/ha to achieve the same production as the grass/clover swards.

At the Orr farm grazing of the herbal leys is predominantly for the ewes and lambs and would start in late January/early February with in lamb ewe lambs, 6 weeks pre lambing.  Dale commented that “Due to the sward quality, body condition of the ewe lambs would be ideal, resulting in quality colostrum production with no requirement for additional meal feeding resulting in good strong lambs”. Once grazed the herbal ley paddocks are then rested for 6 weeks to allow for regrowth and then placed into a 25-30 day grazing rotation from that point on.  Once growth picks up the fields are split up into paddocks that will graze for 5 days at any one time.  Very similar to that of the grass and white clover swards on farm with the only difference being the herbal leys would not be grazed down as tight as the grass swards due to the growing nature of the herbs and legumes. 

Dr David Patterson, AFBI commented that “Recent trials with multi species swards at AFBI Loughgall showed that a post-grazing height of 7-8cm is ideal for such swards, as this allows for reserves to be replenished to give full potential regrowth”.  Dr Patterson also commented that “Preliminary findings from the simulated grazing trials at AFBI Loughgall in 2020 showed that the multi species swards out yielded the grass and grass/clover swards over the season”.

Late October marks the end of the grazing season and the start of the herbal ley rest period which lasts approximately 100 days.  This allows for regrowth to accumulate over the winter period before the ewe lambs start on it again in the following spring.

For Dale at farm level the performance to date from the herbal leys has been more than obvious in many forms. Measures of increased daily live weight gain (DLWG), reduced worm burden of stock grazed on the herbal leys and continued forage growth even throughout the drought period are but 3 of the benefits that have been visible to date.

For instance in the case of Dales ewes once lambed they are placed into 3 mobs all of which are grazed on different swards ranging from Perennial Rye Grass & White Clover (PRG & WC) to herbal leys (Plantain, Chicory, Red Clover, White Clover) with PRG included to that of swards made up purely of herbs and legumes (White Clover mix, Red Clover x 2 varieties, Plantain and Chicory).  The average DLWG results at 10 weeks of age were as follows across the three grazing sward types and show in Dale’s scenario a 16% & 7% increase in DLWG from the herbal leys over that of the PRG &WC swards respectively.

Table 1: Lamb average daily gain at 10 weeks of age on the Orr farm 2021

Sward TypeAverage Daily Live weight Gain
PRG & WC250 grams/day
Herbal Ley with PRG270 grams/day
Pure Herbal Ley290 grams/day
(Dale Orr on farm DLWG data of 2021 lambs)

Dale is a firm believer than once the ewes and lambs are grazing on the herbal leys they should be kept on this type of sward until they have reached their final market deadweight of 21kgs.  The reason for this consistent grazing approach is to stop any alterations in their diet, allowing their stomachs and pallet to become accustomed to the diet of grass, legumes & herbs and keep them on a rising plane of nutrition upon that transition from a milk to forage based diet. 

Historically the average days to slaughter for the lambs would have been in the region of 172 days.  However since the introduction of herbal leys to the sheep enterprise Dale has reduced his days to slaughter by an impressive 27 days, an 18% decrease, resulting in an average days to slaughter of 146.  All achieved with no meal feeding.

Much is yet to be known as to the longevity of the swards as this is only the forth year that they have been growing at the Orr farm.  However, Dale is more than happy with the performance, which is being achieved to date on his farm and plans to continue with the use of herbal leys within his farming system.

The BDG Scheme is funded by the Department of Agriculture, Environment and Rural Affairs and the European Agricultural Fund for Rural Development.