Sheep Research Demonstration farm Athenry - Update

Research to date shows that including white clover in the sward relative to perennial ryegrass alone results in lambs reaching slaughter weight faster – Philip Creighton Researcher

In this video, Philip Creighton, Sheep Grassland Systems Researcher, Teagasc gives an update as to what is happening in the Sheep Research Demonstration farm in Teagasc Athenry.

Lambing commenced on March 3rd and finished on April 8th. Mean lambing date for 2020 was March 13^th. Approximately 85% of the flocks lambed over the first 17 days. Birth weights for singles, twins and triplets averaged 5.9, 5.1 and 4.3kg respectively. Lamb mortality levels averaged 8% for the period birth to 48 hours old. Lambing assistance was recorded with 20% of ewes requiring some level of assistance. Average ewe BCS going out to grass was 3.2.

Grass growth rates were below normal in March averaging 14kg DM/ha/day and so we did supplement ewes for around a week post turnout to reduce demand but have improved greatly in April averaging 40kg DM/ha/day. We began subdivided paddocks in early April to maintain better control on grazing and with excellent weather conditions were able to graze out swards to 3.5cm. This will set up excellent grass quality for subsequent grazing rotations when lambs begin grazing. Due to strong grass growth we made the decision to skip over the last 20% of each farmlet which was closed for silage in mid-April in order to start the second rotation on time.

Fertiliser

To date a total of 57kg of N has been applied per ha (46 units/ac) in two applications in February/March and early April. Preliminary analysis of lamb performance to 5 weeks of age show average daily gains of 281g (13 ewe/ha SR) to 292g (11 ewe/ha SR) /hd/day.

Research

Current grazing systems research projects in Athenry are focusing on the impact of incorporating white clover and other companion forages into sheep grazed swards on the productivity of pasture based lamb production systems with special focus on the animal, environmental and economic impacts.  These projects are split into two main studies

1. An evaluation of incorporating white clover into sheep grazed swards at two fertiliser nitrogen and stocking rate levels on the productivity of pasture based lamb production systems
2. An evaluation of alternative forages in combination with perennial ryegrass to increase animal intake, performance and output in sheep pasture based production systems

Study one is investigating two stocking rate levels (11 or 13 ewes/ha) with three pasture treatments at each stocking rate i)Perennial ryegrass receiving 145kg N/ha/yr, ii)Perennial ryegrass plus white clover receiving 145kg N/ha/yr and iii) Perennial ryegrass plus white clover receiving 90kg N/ha/yr.

Key findings to date show that the inclusion of white clover in the sward relative to perennial ryegrass alone resulted in lambs reaching slaughter weight 9 days faster.  In terms of sward DM production the grass only swards grew 13483kgDM/ha , grass clover swards at 145kg N/ha grew 13926kg DM/ha and the grass clover swards at 90kg N/ha grew 13590kg DM/ha.  While only a small difference is evident between treatments a positive aspect is that the low N treatment (90kg N/ha) is growing just as much grass or slightly more than the other high N treatments (145kg N/ha) with or without white clover inclusion. This is the third year (including establishment year) that this has been achieved.  Sward clover content has averaged 7% of the sward pre weaning and 15% post weaning for the grass + clover treatments. This has major implications from both an economic and environmental point of view while also improving animal performance.

Study two consists of five forage or forage mixture treatments: i) perennial ryegrass only, ii) perennial ryegrass plus white clover, iii) perennial ryegrass plus grazing tolerant red clover, iv) perennial ryegrass plus plantain and v) perennial ryegrass plus chicory. This study is part of the PhD studies of Walsh Scholar Lisa McGrane.  A key focus of this study will be plot based trials which will be grazed by sheep investigating establishment method, post grazing height and establishment seeding rate effects of the grass and companion forage mixtures in an effort to identify if any of these key management steps influence the persistency and longevity of the companion forages as well as their contribution to animal and sward performance.