WA Sheep producer survey results for 2018
Janet Conte, DPIRD, South Perth, WA
Author correspondence: janet.conte@dpird.wa.gov.au
Introduction
Every three years from 2011, the Department of Primary Industries and Regional Development (DPIRD) has surveyed Western Australian sheep producers from the medium rainfall zone and cereal-sheep zone. Producers answered questions about their production systems including sheep management, breeding strategies, involvement in industry and DPIRD training and events and adoption of new technologies. The most recent survey was conducted in 2018 and surveyed a total of 389 producers, 178 from the medium rainfall zone and 211 from the cereal-sheep zone, a very similar number to previous years (377 in 2011 and 368 in 2014). This article presents results on flock size and composition and trends in ram selection and use of Australian Sheep Breeding Values.
Primary enterprise type and production
Producers in the medium rainfall zone have more sheep on average (4835) than producers in the cereal-sheep zone (3682). Overall, fifty-eight percent of the sheep flock were run by 25% of producers. In the medium rainfall zone, 66% of the sheep flock were run by 25% of producers and in the cereal-sheep zone, 49% of the sheep flock were run by 25% of producers.
The average ewe flock size in 2018 was larger in the medium rainfall zone than the cereal-sheep zone for all enterprise types (Table 1). Between 2014 and 2018 the average wool flock increased by 10% in the medium rainfall zone and 15% in the cereal-sheep zone while the average prime lamb flock doubled in size in both zones.
|
| Medium rainfall zone | Cereal-sheep zone | ||
|---|---|---|---|---|
|
| 2014 | 2018 | 2014 | 2018 |
| Wool production | 2240 | 2436 | 1671 | 1991 |
| Prime lamb production | 1367 | 2689 | 1042 | 1921 |
Dual enterprises are the most common type with 63% of respondents having both wool and prime lamb, 27% having predominately wool enterprises and 10% with predominately prime lamb enterprises. This enterprise mix has remained relatively stable throughout the three surveys.
Ram selection and sales
The survey included questions about how producers select their ram source (stud or self-replacing flock) and how they purchase rams (private selection or auction). The largest producers in the cereal-sheep zone were more likely to buy at auction than private sale compared to others in the zone. Smaller producers in both zones were more likely to buy at a private sale.
Ram breeders were more likely to be either wool or prime lamb focussed businesses, whereas dual enterprises tended to buy in their rams. Wool producers in the medium rainfall zone were more likely to breed their own than other producers. Prime lamb producers in the medium rainfall zone were more likely to breed rams for sale than other groups. In the cereal-sheep zone, the results were the opposite with prime lamb producers least likely to breed rams for sale.
There have been two large shifts in ram breeding over the course of the surveys (2011, 2014 and 2018). The percentage of breeders who only breed rams for their own use has more than halved from 13% to 5%, while the number of producers who both breed for their own use and buy in rams has doubled.
Australian Sheep Breeding Values
An Australian Sheep Breeding Value (ASBV) is a prediction of how a sheep’s offspring will perform on a range of important traits such as growth (e.g. birth weight, weight), composition (e.g. fat depth, eye muscle depth), wool (e.g. fleece weight, fibre diameter), reproduction and disease (e.g. worm egg count).
In the 2018 survey, 15% of respondents indicated that they chose their stud or ram source on genetic information and ASBVs and in Merinos this represented 26% of the state flock. The proportion of respondents who always chose their regular breeder had declined from 50% in 2011 to 39% in 2018. Eight percent of respondents indicated that they chose rams based solely on genetic information while a further 33% chose rams based on a combination of visual assessment, performance data and genetic information.
When assessed on the proportion of the flock, the percentage of the Merino flock utilising genetic information was 14% with a further 36% based on a combination of data including genetic. Genetic information was therefore an important factor to producers in nearly half of all rams purchased.
Approximately one in four ram sellers sold all their rams with ASBVs in 2018. The majority (71%) of wool breeders sold all their rams with ASBVs, while 35% of dual enterprise breeders and 16% of prime lamb breeders sold all their rams with ASBVs. Many ram sellers sold at least a portion of their rams with ASBVs with most prime lamb breeders selling around 50% of their rams with ASBVs.
Lamb survival initiative results for 2017
Rebecca Butcher, DPIRD, Moora, WA
Author correspondence: rebecca.butcher@dpird.wa.gov.au
This article presents the results of the 2017 Lamb Survival Initiative. This project is now complete. The results for 2015 and 2016 can be found in the March 2016 and September 2017 editions of the Ovine Observer, respectively.
Introduction
The Department of Primary Industry and Regional Development’s (DPIRD) Lamb Survival Initiative ran from 2015 to 2018 in conjunction with regional grower groups and private consultants. It was aimed at providing support to producers to increase lambs survival and achieve 100%+ marking rates. The initiative provided training and support and allowed producers to benchmark their marking rates against others in similar regions and state-wide.
In order to build producer confidence and skills to lift marking rates to 100%+ the initiative encourage producers to:
- undertake pregnancy scanning for multiples on a significant proportion of their adult ewes
- record and submit data on the reproductive rate, marking rate and weaning rate achieved in the scanned ewe flock/s so that the rates can be benchmarked against producers in similar regions
- attend at least one training course or workshop focused on reproduction
- work closely with industry professionals where reproduction rates are less than expected.
In the final year of the initiative (2017) three producer groups were involved, Facey Group (Woodanilling), Southern DIRT (Kojonup) and a private group based at Augusta. A total of 20 producers participated across the three groups. Lifetime Ewe Management accredited facilitators Ed Riggall and Jonathan England were selected by the groups to provide in depth information on reproduction.
Facilitators met either on-farm with each producer or organised group meetings to provide recommendations on farming practices such as condition scoring, feed budgeting and sheep husbandry.
Information collected around the reproductive cycle included:
- ewe condition score at rams out and pregnancy scanning
- scanning rate (number of lambs scanned per 100 ewes joined)
- marking rate (number of lambs marked per 100 ewes joined)
- weaning rate (number of lambs weaned per 100 ewes joined)
- weaning weights (where facilities available)
- feed on offer (FOO) at lambing and details of supplementary feeding.
Collection of this information has enabled producers to gain valuable understanding on where lambs were being lost throughout the reproductive cycle providing them with targeted ways to improve their lamb survival and marking percentage.
Ewe condition score
As shown in Figure 1, each of the groups maintained a high average condition score (CS) between rams out and pregnancy scanning. Condition score was slightly reduced at pregnancy scanning compared to at rams out at each site, however the loss in condition score was very small being less than 0.15. In previous years, condition score generally increased between rams out and pregnancy scanning however, these results reflect the late break and reduced FOO in 2017.
Feed availability
In 2017, FOO was moderate to low amongst the groups, ranging from 700-1200 kilograms/hectare (kg/ha), and generally lower than in 2016.
Figure 2 shows that in areas where paddock feed availability was higher; ewes were given less supplementary feed, the type of supplement used varied from hay, wheat seconds, oats, barley, an oat/barley mix and/or lupins. Higher rates of supplementary feed were allocated to feeding twin bearing ewes over singles.
Lifetime Wool recommendations are for lambing down ewes in a minimum of 1200kg of dry matter/hectare (DM/ha) for single bearing ewes and 1800kg DM/ha for twin bearing ewes. As this was not possible for most groups, supplementary feeding was critical. Lamb survival can be improved by 15-20% in twin bearing ewes where condition score is increased from 2.5 to 3 through careful management of nutrition (Lifetime Wool). This would result in an extra 30 lambs for every 100 ewes joined.
Reproductive rates
Reproductive rates included the number of lambs scanned, marked and weaned per 100 ewes joined (Figure 3). The Augusta group had the highest reproductive rates for scanning, weaning and marking. Each of the three groups had marking rates about 100%, achieving one of the main aims of the initiative.
As seen in previous years, the greatest lamb loss for each group occurred between pregnancy scanning and lamb marking and was higher in groups with higher scanning percentages. This mortality may be either in-utero, during the birthing process or in the first 72 hours of life, where it has been found that most lamb mortality occurs.
Despite a challenging year with low FOO, the losses between lamb marking and weaning were small, particularly for the Woodanilling and Augusta groups.
Weaning weight
While not all producers involved in the project recorded weights at weaning, the practice is becoming more prevalent than in previous years as producers practice precision farming. The average weaning weights were recorded with the results shown in Figure 4.
The difference between average weaning weight for the lowest and highest groups was almost 10kg. While Southern Dirt (Kojonup) had the highest average weaning weight for 2017, it was 7kg below the group’s average for 2016 due to the poor year.
There are many strategies that can be put in place to increase lamb survival including monitoring the condition score of ewes, scanning for multiples foetuses and preferentially feeding twin bearing ewes, as well as providing shelter, implementing a pest management program and limiting mob size at lambing.
Further information on increasing lamb survival can be found in the September 2016 edition of Ovine Observer or on the website.
If you would like to know more information from the results of the Lamb Survival Initiative, please contact Rebecca Butcher, Sheep Industry Development Officer, Moora on (08) 9651 0540 or rebecca.butcher@dpird.wa.gov.au.
Dry ageing sheep meat for a premium product
Robin Jacob, DPIRD, WA and Melindee Hastie, University of Melbourne, VIC
Author correspondence: robin.jacob@dpird.wa.gov.au
The interest in dry ageing is growing in countries like the USA and Germany, particularly amongst the “foodie” segment of consumers. In the USA for example, the dry aged beef industry has grown from virtually nothing in 2011 to a $10 billion industry, and is equivalent to about 10% of their beef industry. Described by some as the “the chocolate” of meat dishes, the potential is to add value to meat using this traditional method of ageing, where meat is aged under controlled temperature and humidity conditions for weeks or even months.
The process causes tenderisation, the degree to which is dependent of the length of time the meat is aged for after slaughter. Dry ageing potentially also causes the flavour profile to change and intensify. This flavour tends to be rich and ‘buttery’, hence the comparison made by foodies to chocolate. These eating quality factors together can increase the price consumers are willing to pay for meat.
The DPIRD’s Sheep Industry Business Innovation project (SIBI) teamed up with MLA to investigate the possibility of value adding to mutton using dry aging. The project, conducted by the University of Melbourne, included measurements of moisture loss and a Meat Standards Australia (MSA) style consumer sensory panel assessment.
Materials and methods
In this experiment, carcases from 90 cull for age Merino ewes (animal age ranging from 3 to 8 years with an average of 5 years), were aged for 14, 28, 42 or 56 days. For comparison, half of each carcase was wet aged in contemporary vacuum bags and the other half was dry aged using a purpose built dry ageing facility. Dry ageing conditions were tightly controlled with a cabinet temperature range of 0-1.0ºC, relative humidity maintained at 80-85%, and auxiliary fans providing continuous air movement within the cabinet.
Results and discussion
Figure 5 shows preliminary results for weight loss from wet and dry aged legs. The difference in weight loss between ageing treatments is quite dramatic. Regardless of the length of ageing, wet aged legs lost less than 1.7% moisture.
In the dry aged legs, moisture loss was 11.5% after 14 days and increased over time, peaking at 20.6% after 56 days. The difference between moisture loss in dry and wet aged legs was statistically significant for all ageing periods.
Ageing for extended periods to achieve tenderisation and flavour effects caused weight loss that increased with time. Quantifying the weight lost in this way allows for a better understanding of the cost of the process, because weight loss reduces the amount available for sale compared to wet ageing.
Justifying the cost of any weight loss with a price increase, in dollars per kilogram, will depend on the associated flavour and tenderness attributes. A future edition of Ovine Observer will report the consumer assessment results, comparing the tenderness, juiciness and flavour of wet and dry aged sheep meat.
How important is odour in attracting blowflies?
Author correspondence: johan.greeff@dpird.wa.gov.au
This article describes the different ways the role of odour in attracting blowflies is being investigated.
Introduction
The Breech strike project was initiated in 2006 with the establishment of the research flock on the Mt Barker research station in Western Australia and supported by Australian Wool Innovation. Six hundred Merino ewes were sourced from 10 industry and three research station flocks from DPIRD.
It has been demonstrated during the project that breech strike is a repeatable trait and any animals that has been struck should be culled as these animals are more likely to be struck again. This factor together with the large differences that exist between sire progeny groups in breech strike susceptibility, and the fact that we could not visually differentiate between susceptible and resistant sheep, indicated that the susceptible animals are likely to have an additional factor(s) that attracts blowfly strike.
Thus the focus of the experimentation shifted towards identifying these elusive factors, the most obvious being odour. A proof of concept experiment was previously carried out with Hanrob Dog Academy where three dogs were trained to determine whether they would be able to distinguish between wool from resistant and susceptible sheep (see WA Breech Strike Newsletter No. 6). Wool from unstruck sheep taken prior to the breech strike season was collected from the breech of the extreme ewes mentioned above in the repeatability study (published in the September 2018 edition of the Ovine Observer), and regularly forwarded to Hanrob Dog Academy to train the dogs.
Identifying wool from struck sheep using dogs
After completing their training, one dog was 100% accurate in differentiating between the wool from susceptible and resistant sheep that was used to train him. In a double blind test (neither the handler nor the dogs knew what the samples were), the dogs were then tested on wool from the CSIRO breech strike flock in Armidale to which they have never been exposed.
The best dog was 82% accurate in identifying the resistant sheep and 92% accurate in ignoring the susceptible samples and other dummy wool samples used to distract the dogs. This result indicated that an odour component was likely and that odour may contribute in attracting flies to susceptible sheep.
If an odour is confirmed, then it opens up additional opportunities depending on whether the odour components act as repellents or as attractants. If a repellent, then it offers opportunities to find new chemicals to protect sheep from breech strike; if they act as an attractant, then it offers opportunities to develop more effective methods to trap blowflies than are currently available, and to identify sheep that are be less attractive to blowflies.
The University of Western Australia (UWA) has extensive experience in identifying odour that attracts insects, and in the identification of volatile chemical components that contribute to germination of specific seeds. A joint project with UWA was thus initiated to identify the specific odour components that are secreted by breech wool.
More than 1500 different compounds have been identified across both the DPIRD (formerly DAFWA) and the CSRIO Breech strike flocks, using gas chromatography. A large number of these volatile components are unknown and are currently being investigated to determine which will attract flies.
Two different methods are being used: the electro-antennagram detector and the behaviour of blowflies when exposed to these compounds.
Electro-Antennagram Detector (EAG)
The EAG is presented in the following picture. It is connected to a Mass spectrometer (MSD).
The arista of a blowfly is placed between two electrodes and the specific volatile component is determined in the MSD and blown over the arista through a glass tube. The electrodes measure the voltage differential when the neurons fire and the resulting pattern is shown in Figure 6.
When it has been shown that the flies recognise specific volatile components through the firing pattern of its neurons, then it indicates that they have specific neural receptors for those compounds. However, it is still unknown whether these compounds will elicit a specific behavioural response (repelled or attracted), so likely candidates still need to be tested using behavioural methodology.
Blowfly behaviour
The behaviour of blowflies as they find susceptible sheep and lay their eggs is an important area of research and an area of specialist skills. We invited Dr Bekka Brodie from Ohio University (USA) to participate in this work. She has studied the ordinary bottle green blowfly, Lucilia sericata, a cousin of the sheep blowfly Lucilia cuprina, and she identified specific chemical odour signatures that attract L. sericata.
She assisted us in fine tuning our EAG methodology to get better neural electrical responses but, more importantly, she demonstrated very quickly that L. cuprina is not attracted to the same odour compounds that attract L. sericata. This was a major finding which explains why L. cuprina prefers live animals while L. sericata prefers carrion (dead animals). Clearly, there is something specific in live sheep that attracts L. cuprina as they do not lay eggs on carrion.
Up to now, we have assessed fly behaviour and what attracts them in an artificial environment, but we need to determine what attracts, or repels them under natural conditions. Their behaviour and how they identify susceptible sheep under natural conditions will be an important future area of research as we determine how they are attracted or repelled by these factors.
South West Western Australia Sheep density
The Agricultural Census is conducted by the Australian Bureau of Statistics every five years and collects information on commodities (including average farm size and number of livestock). Based on the results of the most recent census, which was conducted in 2016, a map of sheep density (sheep/hectare) in the different shires of the South West region of Western Australia can be found below.
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