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Merino weaner monitoring project, “Hillcrest” Gunning

March 2016 update

Compiled by:

Matthew Lieschke

Livestock Officer

South East Local Land Services

Published by the Local Land Services

Merino weaner monitoring project

First published March 2016

More information

Matthew Lieschke | Livestock Officer, South East Local Land Servies | Goulburn NSW 2580

www.lls.nsw.gov.au

© State of New South Wales through Local Land Services, 2016.

Disclaimer: The information contained in this publication is based on knowledge and understanding at the time of writing March 2016. However, because of advances in knowledge, users are reminded of the need to ensure that information upon which they rely is up to date and to check currency of the information with the appropriate officer of Local Land Services or the user’s independent adviser.

Merino Weaner Monitoring Project – March 2016 update

Local Land Services March 2016 1

Background Weaner losses in both Merino and cross-bred flocks are highly variable and can cause significant financial loss. Management not only plays a critical role in minimising losses, but it also determines the financial return from young stock.

Weaner survival is a function of BOTH weaning weight and post weaning growth rate. Animals that fail to gain weight post-weaning become vulnerable and are prone to dying. Adequate nutrition is also needed to ensure weaners continue to grow and meet liveweight targets for joining.

A weaner monitoring project was established at “Hillcrest”, Gunning. The main purpose of the project was to benchmark weaner performance and provide a reference point for sheep producers across the Southern Tablelands

Project aims − To monitor Merino weaner health and performance over the first 7-8 months post weaning − To highlight the nutritional requirements of young stock − To help sheep producers minimise losses and develop feeding strategies to ensure production goals are

achieved

Results to date

January 2016 The 2015 drop of Merino lambs were weaned and drenched with Genesis Extra (1g/L abamectin and 50g/L closantel) on 6 - 9 January 2016 and shorn on 11 January 2016. The weaners selected for the project are ewe weaners from Grassy Creek bloodline ram and Merryville bloodline ewes. Lambing occurred in mid-August with the lambs marked on 9 October.

On 15 January 2016 the ewe weaners were visually drafted off into low, medium and high weight groups. This was done so that livestock performance of three distinct groups could be monitored separately (Figure 1). Approximately 30 weaners from each group were tagged with an electronic ear tag and weighed (Table 1).

Figure 1 Method of allocation for tagging weaners

Merino Weaner Monitoring Project – March 2016 update

Local Land Services March 2016 2

Table 1: Weaner liveweight as of 15 January 2016

Group LWT

(Ave)

Min lwt Max lwt No. of animals

High 23.5 19.5 28.5 35

Mid 18.9 15.0 25.0 30

Low 15.3 11.0 18.0 34

The lambs were stocked on native pasture containing a mix of annual and native grasses including danthonia, microlaena, vulpia and annual ryegrass. Weaners had access to a very limited green ‘pick’ consisting of mainly couch grass and microlaena. It was estimated that the paddock contained around 1200kg DM/ha of dead material. A sample of the dead material was taken on 15 January and sent to Feedtest lab at Wagga Wagga. The results were:

− Digestibility: 44% (5.9 ME) − Protein: 6.2%

The results from the lab confirmed that the dry standing pasture was of very low nutritive value, particularly for young stock.

Photo 1: paddock being grazed by Merino weaners (15.1.16). Dead material contains very little energy and protein.

Photo 2: limited green pick for weaners (15.1.16)

Merino Weaner Monitoring Project – March 2016 update

Local Land Services March 2016 3

February 2016 Widespread rainfall in late January provided a real boost for livestock across the region, particularly young stock. Gunning received 83mm of rain between 22 January and 2 February. This was enough rainfall for native pasture to respond and provide a flush of green feed. Sub clover also germinated.

The tagged weaners were drafted off and reweighed on 24.2.16. Results are presented in Table 2.

Table 2: Weaner liveweight as of 24 February 2016

Group lwt ave

Min lwt Max lwt No. of animals

Total lwt gain (kg) Daily lwt gain (g/hd/day)

Ave Min Max Ave Min Max

High 27.6 22.5 34.0 35 4.2 0.0 7.0 107 0 179

Mid 23.6 18.5 29.5 27 4.7 2.0 8.0 120 51 205

Low 19.0 15.0 22.5 28 3.7 1.0 7.5 95 26 192

The February weighing revealed that the weaners on average gained 4.4kg over the period, which equates to around 110g/hd/day. This was achieved on a green pick made up of mainly weeping grass (Microlaena stipoides). Interestingly, the variation between animals was staggering, with some weaners putting on 1-1.5kg and others putting on over 6kg. The other interesting point to note was that animal performance was similar across all size categories.

Photo 3: Microlaena still providing a good source of green feed in late February

Merino Weaner Monitoring Project – March 2016 update

Local Land Services March 2016 4

March to June period Weaners received a significant boost from the green pick, but feeding rates will need to be increased as the green disappears. Level of feeding will be a function of the quantity and quality of pasture available and growth rate targets.

So, what growth rate should you be aiming for? In order to work this out the first step is to identify your end point and work backwards (Figure 2).

Figure 2: Pathway to minimum joining weight

In reference to Figure 2, the key points are:

− In the case of ewe weaners the ultimate goal is getting them up to a critical weight so they will join. Joining weight is a function of mature ewe weight, but for most Merino flocks 40kg should be seen as the minimum joining weight. In the end, a balance is needed between providing enough nutrition so they reach joining weights, but not feeding too much as this puts extra cost into the system.

− Providing that weaners are in good health (i.e. not under too much pressure from worms or other animal health issues) we can expect weaners to put on 12-14 kg in spring. Therefore, in order to meet joining weights weaners need to be at least 28kg at 1 September.

− Again, providing weaners are in good health we can expect weight gain of around 1kg/month during winter, or 3kg over the 1 June – 31 August period.

− In order to meet the end target weaners need to be a minimum of 25kg by 1 June. While the mob average in this study is sitting at 23.7kg, 25% of weaners are 20kg or less.

− As shown in Figure 2, the lighter weaners will need to put on 5 - 7kg in the next 3 months in order to reach the critical mating weight. If this isn’t achieved the lighter weaners will need to be supplemented at a later stage to have any chance of joining successfully.

Merino Weaner Monitoring Project – March 2016 update

Local Land Services March 2016 5

How much do I need to feed? Table 3 provides a guide on supplementary feeding rates for the various weight ranges with the aim of reaching a minimum of 25kg liveweight by the start of June. Three scenarios are presented:

1) Full hand feeding: is where there is very little paddock feed left. In this situation feeding roughage becomes important as stock aren’t getting sufficient roughage from the paddock. 2) Old dead material: is carry-over dead plant material from last spring. This material would be significantly weathered, white in colour and of very low quality (i.e. 40-45% digestibility). 3) New dead material: refers to ‘green’ feed that grew in response to the January rainfall but has burnt off in the last couple of weeks. This herbage will still be of good quality (i.e. 65 - 70% digestible) and provide adequate nutrition for weaners.

Table 3: Grain feeding rates to achieve target weights by 1 June

Current wt

1 March

Target wt

1 June

Required growth rate

(g/hd/day) Feeding rate (g/hd/day)

Full hand feeding

Old dead material

New dead material

18 25 78 520 410 0

20 25 56 480 360 0

25 27 22 420 260 0

30 30 0 410 220 0 The feeding rates presented in Table 3 are Derived from GrazfeedTM and based on a cereal grain ration containing 85% barley and 15% lupin grain (13 ME, 15% protein). Note that these rates will need to be fed until the autumn break provides a green pick.

Note the impact of the dry feed in the paddock on feeding rates. The critical thing is to have a close look at what sheep are eating and monitor it frequently so you can make timely adjustments.

Based on the above feeding rates it would also be worth drafting off weaners that are 22kg and below and feeding them separately using the higher rate. Don’t forget lime and salt! Grain is low in both Calcium and Sodium. These can be simply put out in troughs and fed ad lib in the paddock. If trail feeding ad 1.5% lime and 0.5% salt.

More information For further information contact:

Matthew Lieschke | Senior Land Services Officer – Livestock South East Local Land Services Level G | 159 Auburn Street | Locked Bag 2048 | Goulburn NSW 2580 T: 02 4824 1913 | F: 02 4828 6750 | M: 0428 271 127| E: matthew.lieschke@lls.nsw.gov.au www.lls.nsw.gov.au

www.lls.nsw.gov.au

Acknowledgments Thanks to Jack and Jennifer Medway of “Hillcrest” for hosting the project and for their assistance. Thanks also to Phil Graham (NSW Agriculture) for his help and guidance with the project.