LUCERNE had a positive effect on sheep live weight gain, but no impact on wool growth and quality in a trial last year at Robert, David and Glenn Beard's Meckering property.
The research was carried out by Muresk Honours student Maxine Brown in association with the Agriculture Department's Low Recharge Cropping Systems Project.
Ms Brown monitored weight gain and wool growth for 180 Merino ewe weaners grazing annual pasture and lucerne over an eight month period.
With 4000ha on three properties north of Meckering and north of Cunderdin, the Beard family planted lucerne across 10pc of the property to make use of summer rainfall, reducing recharge on the farm.
The Beards are also interested in the productivity benefits of lucerne for their 5000 fine wool Merinos.
The lucerne was established in June and July 2002 and a mix of Salado, Eureka, Sceptre and L69 sown at 4kg/ha.
Superphosphate and lime were spread before sowing.
Ms Brown started monitoring the 180 ewes fortnightly for weight gain on December 27, 2002.
Wool growth and quality was measured using dye bands at six-weekly intervals and 12-weekly mid side patch clipping.
Sheep were rotated through the lucerne paddocks fortnightly and Ms Brown admitted that stocking rates across the lucerne and the annual pasture were less than average for the property.
The sheep were rotated through paddocks of annual grasses during the winter and Cadiz, wheat and stubble paddocks in the summer when they had additional supplementary feed of wheat, lupins and hay.
Average stocking rates during the trial period in the lucerne were 2.5 sheep per hectare, compared to 1.45 sheep per hectare in the annual pasture and stubbles.
Despite the supplementary feed that accompanied summer grazing of the stubble paddocks, Ms Brown said summer weight gain from the lucerne was significantly more than the annual pasture and stubble.
"Daily weight gain from January to April for the 90 ewes on the lucerne was 118g/day, compared to 76g/day for the sheep on the annual pasture and stubbles," Ms Brown said.
"This result was reversed during winter time, when the daily weight gain on the annual pasture was 127g, compared to 42g on the lucerne."
Half way into the trial, half of each group of sheep was moved across to the other pasture type to gauge compensatory growth.
But Ms Brown said there was no evidence of compensatory growth of animals grazing annual pastures and stubbles in summer and lucerne in winter.
"Grazing lucerne over summer and annual pastures in winter achieved superior weight gains, but there was no difference in eye muscle area or fat depth between the treatment groups," she said.
Somewhat unexpectedly, the quality of the pastures had no effect on wool growth or quality.
Ms Brown said in this trial, the increased nutrients available to the sheep from the lucerne resulted in live weight gain rather than wool growth.