Lamb Survival Initiative - comparing 2015 and 2016 results
Rebecca Butcher, Department of Primary Industries and Regional Development (DPIRD), Moora
Corresponding author: rebecca.butcher@dpird.wa.gov.au
This article presents a comparison of the results of the 2015 and 2016 Lamb Survival Initiatives. The results of the 2015 Lamb Survival Initiative are available in the March 2016 edition and the 2016 results are available in the September 2017 edition of the Ovine Observer.
Introduction
The Lamb Survival Initiative, through involvement with regional grower groups, aims to provide the support required for producers to achieve 100%+ lamb marking rates. The initiative provides training and support, encouraging producers to set achievable targets and benchmarking their marking rates against producers in similar regions and across the state.
The Lamb Survival Initiative is in its third year with the first initiative run in 2015. In 2015, producers from five grower groups were involved in the initiative and in 2016, producers from six grower groups participated.
The grower groups were spread throughout the southern region of Western Australia (WA) and included Facey Group (Wickepin), Southern DIRT (Kojonup), the Gillamii Centre (Cranbrook), ASHEEP (Esperance) and three independent groups, with a total of 34 participants.
In order to build producer confidence and skills to lift marking rates to 100%+ the initiative encourages 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.
Lifetime Ewe Management accredited facilitators Ed Riggall and Jonathan England were selected by the groups to provide in depth information on reproduction. Facilitators meet either on-farm with each producer or via group meetings to provide support and training on topics such as condition scoring, feed budgeting and husbandry practices for increasing lamb survival.
Information collected by producers 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 were 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 lambing percentage.
Analysis of results from the initiative comparing 2015 and 2016
Ewe condition score
In general, the groups showed a trend of increasing ewe condition score between the periods of removing the rams and pregnancy scanning (Figure 1). As shown in Figure 1, producers from the ASHEEP, Gillamii Centre and Southern DIRT groups maintained a high average condition score (CS) of 2.9 or above in their ewes between rams out and pregnancy scanning in both 2015 and 2016.
The average ewe condition scores were higher in 2016 than 2015 for the ASHEEP and Facey Group groups, which reflects the significant increase in FOO available at each of these sites in 2016 compared to 2015. While FOO increased between years at all sites that were measured in both 2015 and 2016, the difference in FOO was greatest at these two sites.
In 2016, producers from the Southern DIRT and West Midlands groups saw a moderate increase in average ewe condition scores of 10%, while producers from the Facey Group and Boyup Brook groups saw a slight increase between rams out and pregnancy scanning.
There was a reduction in the average ewe condition scores in the ASHEEP and Gillamii Centre groups in 2016, however the change was negligible (<2%) and was not reflected in the 2015 condition scores.
Feed availability
Figure 2 displays the available amount of feed on offer and supplementary feeding across both 2015 and 2016 for all groups. FOO increased between 2015 and 2016 for all groups measured in both years.
In 2016, average FOO at lambing was high for all groups, with the difference between years most notable for ASHEEP and Facey Group producers, reaching almost one tonne difference for ASHEEP and exceeding one tonne for Facey Group.
The lowest average FOO in 2016 was 1200 kilograms per hectare (kg/ha) (Southern DIRT), which was actually greater than the highest average FOO in 2015 being 1060kg/ha (ASHEEP). This may be in part due to the areas in which the groups resided experiencing decile 1 rainfall during the growing season in 2015.
Most groups continued to provide supplementary feed to ewes even when FOO was high in both years (Figure 2). A variety of supplementary feeds were used including hay, wheat seconds, oats, barley, an oat-barley mix and/or lupins. The majority of the supplementary feed recorded was used for feeding twin bearing ewes.
Reproductive rates
In Figure 3 reproductive rates are recorded and include the number of lambs scanned, marked and weaned per 100 ewes joined in 2015 and 2016. As in 2015, the greatest lamb loss in 2016 for each group occurred between pregnancy scanning (dark blue – 2015, light blue – 2016) and lamb marking (dark green – 2015, light green – 2016). This mortality may be either in-utero, during the birthing process or in the first 72 hours of life, when 80% of lamb mortality occurs.
Producers in the ASHEEP group had large losses during this period in both 2015 and 2016. Producers in the Southern DIRT, Boyup Brook and West Midlands also suffered large losses during 2016, which is interesting given the reasonable condition score and FOO for each of these groups. Comparatively, the losses during this period were smaller in the Facey Group and West Arthur groups.
Surprisingly the number of lambs weaned (2015 – orange, 2016 – yellow) increased from the number of lambs marked (2015 – dark green, 2016 – light green) in several groups, occurring in the West Arthur group in 2015 and the Gillamii Centre and Facey Group groups in 2016. The increases were relatively small and are likely to reflect some out-of-season lambing and/or ewes and lambs that were not present at marking.
There are many practices that can be put in place to increase lamb survival. These have been long understood and were reiterated through the Lamb Survival Initiative group participation.
The practices include the importance of monitoring the condition score of ewes, scanning for multiples, preferentially feeding twin bearing ewes, as well as providing shelter and limiting mob size at lambing especially for those ewes with multiples.
Weaning weight
While not all producers involved in the project recorded lamb weights at weaning, the average weaning weights are shown in Figure 4. It’s no surprise that average weaning weights were higher in 2016 which is most likely due to the better seasonal conditions favouring higher FOO and higher liveweight growth.
Weaning weight can have an important effect on post weaning survival and growth rate. Making More from Sheep states that “a 14kg weaner has a 34% lower mortality risk than a 12kg weaner, whereas a 20kg weaner has a 22% lower mortality risk than an 18kg weaner”.
The average weaning weights for each of the groups was greater than 20kg, and sometimes more than double this, reflecting the reduced mortality seen in the groups.
Producers involved in the initiative over the last couple of years stated their reason for joining being the desire to improve lamb survival (especially in twin born lambs), to improve their management skills and to improve lambing percentage. Overall feedback from producers involved indicated that they found the Lamb Survival Initiative to be highly valuable to their business.
Some of the key take home messages listed included ensuring that the right sheep were selected for your enterprise, feeding sheep to their requirements was important, that condition score at joining was paramount and managing multiples in smaller mobs increased lamb survival.
Further information on increasing lamb survival can be found in the September 2015 edition of Ovine Observer, or on the DPIRD website.
If you would like to become involved in the 2018 season of the Lamb Survival Initiative, please contact Rebecca Butcher, Sheep Industry Development Officer, Moora on +61 (0)8 9651 0540 or rebecca.butcher@dpird.wa.gov.au.