Animal Science Professor Steve Morris
Few coarse woolled sheep farmers today are recovering the costs of shearing, whilst many are not.
An alternative option is to breed a “no wool” sheep like the Dorper or “self-shedding” sheep that sheds its fleece once a year like the Wiltshire.
Some farmers have graded-up to a Wiltshire flock but quantified research results showing the potential impacts for other sheep farmers who might be contemplating a move to a self-shedding sheep, is currently lacking. Now, a research project at Massey University’s Riverside Farm in Wairarapa is gathering the information to do this.
Professor in Animal Science Steve Morris says the project aims to quantify the benefits and costs of the change from a Romney sheep to a self-shedding Wiltshire.
“The project has two aspects - firstly to model the profitability of such a change and secondly to undertake a multi-year flock study recording production and performance as the flock is graded to a Wiltshire flock.
Half Wiltshire hog
“Modelling has indicated that in the long-term, a change to a self-shedding flock will be profitable. Modelling suggests the coarse wool price would have to exceed $4.15 per kilogram to break even on the costs of shearing in many farming scenarios. However, this model is limited by insufficient data in production data during the transition period. Some of the assumptions were based on anecdotal industry data, or trial data from more than 20 years ago,” Professor Morris says.
The project started in March 2020 with 400 Romney ewes bred to either Wiltshire rams or Romney rams. The resulting ewe lambs from this first breeding, half bred Wiltshires, were then bred as hoggets to Wiltshire rams in late April 2021 to generate three quarter Wiltshire lambs, that were born in October 2021. The project continues with seven eighths Wiltshire lambs to be born in 2022 and fifteen sixteenths to be born in 2023. At each lambing they will be compared to the base Romney flock at Riverside Farm.
Lambing of half Wiltshire cross ewe hoggets started in late September 2021 and the lambs were weaned on 17 December. The three-quarter Wiltshire cross lambs grew at 270 grams per day to average 24.6 kilogram at weaning at an average of 75 days of age while the Romney lambs grew at 260 grams per day to weigh 23.7 kilogram at weaning.
Wiltshire three quarter cross Lambs born and weaned per ewe were 1.32 and 1.15, respectively. For the comparable group of Romneys ewe hoggets, the equivalent figures were 1.29 and 0.96. Growth of the three-quarter Wiltshire cross ewe lambs from weaning between 17 December and 26 January was 188 grams per day to reach a live weight of 31.0 kilogram. This means they are on target for mating liveweights of 40 kilograms in late April. The comparable group of Romneys weighed 30.7 kilogram.
The three-quarter Wiltshire cross ewe lambs were given a shedding score on a scale of one to five (fully shed) on 26 January and 90 per cent showed some shedding (see fig 1 b). At the same date in 2021 for the half Wiltshire cross lambs 40 per cent showed some shedding (see fig 1 a).
A shedding score taken on 2 February (see Figure 2) revealed all except 10 per cent had some shedding and the average shedding score was 1.8, on the 1-5 scale). These half Wiltshire cross ewes had a dag score of 0.7 while the comparable group of Romneys had a dag score of 0.6 (i.e. no discernible difference) on a scale of zero (no dags) to five (very daggy).
This trial is funded by the L. A. Alexander Trust and the Massey University Foundation.
