Comparing the performance of weaned Welsh Mountain lambs, grazing chicory, high sugar grasses, rape and old pasture
Title of Experiment: Comparing the performance of weaned Welsh Mountain lambs, grazing chicory, high sugar grasses, rape and old pasture
Date started: September 2015
Contact: Dr Prysor Williams
Location: Henfaes Research Station (Lowland site)
- To determine the effect of grazing four forage types (chicory, forage rape, high sugar grass, old pasture) on the growth rates of Welsh mountain lambs
- To assess the economic advantage for using forage finisher over feed concentrate
The trial was located at Bangor University Henfaes Research Centre in the lowland part of the farm. Four forage treatments (chicory/high sugar grass mix, forage rape, white clover/high sugar grass mix, and old pasture (ca. 20 years old)) were used. Twenty lambs of similar live weight were randomly allocated per hectare per each of the four treatments (Figure 1). Lambs were weighed at the start of the experiment and every two weeks thereafter over a period of 6 weeks.
On the final day of the experiment and just before slaughtering date, carcass classification and fat and muscle composition were measured using visual as well as ultrasound scanning machine methods (Figure 2).
Figure 1. The four experimental plots at Henfaes Research Centre. A: the old pasture, B: chicory/high sugar grass mix, C: white clover/high sugar grass mix, D: forage rape
Figure 2. Ultrasound scanning lambs for muscle and fat depth
The following were the main findings from this trial:
- All four forages are suitable for fattening lambs systems
- The chicory/high sugar grass mix and the white clover/high sugar grass mix treatments gave the most rapid growth rate. The muscle to fat ratio was high (Figure 3). These forages could be suitable for finishing the smaller lambs from upland flock systems quickly.
- Forage rape produced the heaviest carcasses, but they had the highest fat content (Figure 3) and took twice as long to finish. Forage rape could be considered as suitable finishing forage for lowland lean breeds which tend not to put on much fat.
- Lambs that had been grazing the old pasture performed grew most slowly out of all treatments. Muscle content was also lowest in this treatment (Figure 3).
- Establishment costs were higher for chicory/high sugar grass mix than they were for forage rape; however forage rape will only persist for one year whereas chicory will persist for five years (subject to the appropriate grazing regime). Although the old pasture would have no establishment costs, it would give the poorest economic return.
Figure 3. Mean fat and muscle depths in lamb carcasses from four grazing regimes.
Figure 4. The open day at Henfaes Research Centre in conjunction with Menter a Busnses