Ovine Observer

New breeding values to target more live lambs

Emma McCrabb, Clara Bradford and Peta Bradley
Meat and Livestock Australia
Author Correspondence: emcrabb@mla.com.au

Introduction

Number of Lambs Born (NLB) and Number of Lambs Weaned (NLW) have been the primary Australian Sheep Breeding Values (ASBVs) used to improve reproduction. While NLB and NLW have been useful selection traits to improve reproduction, they can mask the true extent of lamb losses. As NLW targets net reproduction, breeders are not able to target the specific stage of the reproductive cycle they wish to improve. The Animal Genetics and Breeding Unit based at the University of New England and Sheep Genetics have developed new reproduction research breeding values (RBVs) that allow producers to target different stages within the reproduction cycle. The new RBVs were released for LAMBPLAN (maternal breeds) in 2019 and for MERINOSELECT in 2020.

How was the data collected?

Data is required to estimate the heritability and correlations for new traits. As such, to enable genomic prediction for traits, a reference population where animals are genotyped and phenotyped (measured) for the trait of interest needs to be established. The MLA Resource Flock captures phenotypes and genotypes for a range of traits including the difficult to measure carcase and eating quality information. However, the daughters from the industry sires used in the Resource Flock are not retained and recorded for reproduction. To capture records and develop a reference population for the new reproduction component traits, breeders were engaged as satellite flocks to the MLA Resource Flock. Key steps in this process included:

• Short-listing Merino and maternal flocks that had a minimum of three years of historical reproduction records for the current Number of Lambs (NLW) analysis
• Contacting breeders to be involved as a satellite flock
• As part of the satellite flock breeders were required to:
  • genotype all their maiden ewes
  • record these ewes for all on-farm reproduction traits
  • retain all ewes for two joinings, including dry ewes and ewes that lambed and lost

There were four drops of ewes from maternal flocks included as part of this project. Breeds sampled included Border Leicesters, Coopworths, Maternal Composites and Corriedale, with more than 28 breeders engaged across five states as part of the research dataset. Once the maternal RBVs had been established, the process was repeated for Merino breeders, engaging 16 flocks from four states.

Since the release of the Maternal RBVs in 2019 there has been an increase in the number of records for all traits across industry flocks, partially as a result of the release of the RBVs. The increase in reproduction data has already allowed the re-estimation of genetic parameters in 2020 for the Maternal RBVs. 

What are the new reproduction RBVs?

Table 1 summarises the traits reported as part of the new reproduction RBV analyses including the unit in which the breeding values are reported and the trait description.

These traits are reported as an adult and/or yearling traits.

YERA is not currently available for the MERINOSELECT analysis as there were not enough records in Merinos to accurately estimate the genetic parameters.

How do you use the new RBVs?

These RBVs are reported alongside ASBV traits on the Sheep Genetics website. They are highlighted in purple to distinguish them from routine ASBVs and to define them as being in their research phase. As more data is recorded, it is intended that these RBVs will be transitioned to ASBVs within three years.

Percentile band tables are available on the website to give producers an idea of industry benchmarks for these RBVs. These aim to provide context around the values to make them more meaningful to producers. This allows breeders to include RBV traits in their SMART breeding objective.

These RBVs can be included in a breeding objective by:

1. Using the percentile band tables to identify where the flock currently sits
2. Using this table to determine a direction of gain and target value to be included in your breeding objective

Where can I find more information?

The Research Breeding values (RBVs) are delivered by Sheep Genetics, a business unit of MLA. Sheep Genetics have support staff that are able to assist in any enquiries related to the new breeding values or genetic evaluations in general. Alternatively, there are also fact sheets explaining these on the Sheep Genetics website.

Sheep genetics contact:
E: info@sheepgenetics.org.au
P: 02 8055 1818

Supplementary to Sheep Genetics, MLA has also developed a genetics hub.  An online website that has a range of tools and resources for commercial producers. On the hub cattle and sheep producers can find:

• ‘Pick the performer’ graphics demonstrating the value of investing in quality breeding values
• Videos of commercial producers demonstrating how breeding values have helped increase profits in their herds and flocks
• How-to animated tutorials outlining the basics of breeding values, setting a breeding objective, indexes and picking a high-performing sire
• Videos explaining the different traits available for cattle and sheep
• Contacts and other resources for further support.

Intramuscular fat as a predictor of sheepmeat eating quality

L. Pannier^1,2, R.A. O’Reilly^1,2, F. Anderson^1,2, G.E. Gardner^1,2, D.W. Pethick^1,2
1Australian Cooperative Research Centre for Sheep Industry Innovation, Armidale, NSW 2351, Australia
² College of Science, Health, Engineering and Education, Murdoch University, Murdoch, WA 6150, Australia
Author correspondence: l.pannier@murdoch.edu.au

Introduction

Sensory perception of sheepmeat is a key factor influencing consumer demand, food choice, repeat purchase behaviour, and willingness to pay (Pethick, Banks, Hales, & Ross, 2006). Many factors affect sheepmeat eating quality, and one of these factors is intramuscular fat percentage (IMF%) (Pannier, Gardner, O'Reilly, & Pethick, 2018). IMF% improves consumer sheepmeat sensory scores (Pannier et al., 2014), and therefore a measure of IMF% is recognised as an important predictor of sheepmeat eating quality in proposed grading systems, such as the Meat Standards Australia (MSA) system. The current MSA sheepmeat pathways system lacks individual objective carcass measurements for traits like IMF% and thus segregation of quality grades between different cuts is not possible. Low to moderate correlations for IMF% (r2= 0.34 – 0.40) exist between loin and other cuts of the fore and hind sections (Anderson, Pethick, & Gardner, 2015). Hence there is potential to predict eating quality of these cuts based on the IMF% of the loin, however it may be necessary to measure IMF% in individual cuts to describe the variability in eating quality. Therefore, we hypothesised that IMF% of each individual cut will provide a more accurate description of that cut eating quality than using IMF% of only the loin.

Methods

Lambs (n=918) from the Meat and Livestock Australia Resource Flock, located at Katanning (WA), were slaughtered at a commercial abattoir and their carcasses subjected to medium voltage electrical stimulation. Loin and topside cuts were collected from 708 carcasses, while the loin, topside, knuckle, outside and rump cuts were collected from the remaining 210 carcasses. In total, 2466 cuts were collected for sensory testing by untrained consumers. Each cut was sliced into 15mm thick steaks prior to grilling according to MSA protocols. Each consumer tasted six test samples on a scale of 0-100 for overall liking. To date, 11 sessions have been conducted including 660 consumers tasting 396 cuts. IMF% was measured on every loin, as well as the topside, outside and rump of the 210 carcasses. Linear mixed effects models in SAS (SAS Version 9.1) were used to analyse consumer scores for overall liking. The models included fixed effects for cut (loin, topside, knuckle, outside and rump), sex (female, male), and birth type (single, twin, triplet), with either IMF% of the loin only or IMF% of all individual cuts (IMF within cut) fitted as a covariate. Animal identification, and consumer within each eating quality session were included as random terms.

Results

Both loin IMF% and IMF% of the individual cuts were positively associated with consumer overall liking scores (P<0.05), however this effect varied between the different cuts. Loin IMF% was positively associated (P<0.05) with overall liking in the loin and the topside cuts with scores increasing by 11.1 and 5.9 units respectively over a range of 2.5% - 7% IMF. There was no association (P>0.05) between loin IMF% and overall liking in the knuckle, outside and rump cuts. When IMF% of the individual cuts was included in the overall liking model, increasing IMF% from 2.5% to 7% was associated with an increase in overall liking score of 10.7 units for the loin only, with no effect (P>0.05) in the other cuts.

Discussion and conclusion

These preliminary results reject our hypothesis that IMF% of each individual cut will account for more variation when predicting eating quality within that cut compared to using only loin IMF%. Hence there is no advantage in using cut specific IMF% to predict eating quality, and multiple measurements of IMF% in the different muscles might not be needed. The results also indicate that utilising a single site measurement of loin IMF% can describe the eating quality variation of the loin and topside cuts, however further work is required to investigate factors other than IMF% that explain variation in eating quality in the other cuts in sheepmeat. Furthermore, the dataset used was still relatively small (396 of the total 2466 cuts eaten to date) and hence requires further investigation when complete. Correlations between all muscles for IMF% will also be tested.

References

Anderson, F., Pethick, D. W., & Gardner, G. E. (2015). The correlation of intramuscular fat content between muscles of the lamb carcass and the use of computed tomography to predict intramuscular fat percentage in lambs. Animal, 9(7), 1239-1249.
Pannier, L., Gardner, G. E., O'Reilly, R. A., & Pethick, D. W. (2018). Factors affecting lamb eating quality and the potential for their integration into an MSA sheepmeat grading model. Meat Science, 144, 43-52.
Pannier, L., Gardner, G. E., Pearce, K. L., McDonagh, M., Ball, A. J., Jacob, R. H., & Pethick, D. W. (2014). Associations of sire estimated breeding values and objective meat quality measurements with sensory scores in Australian lamb. Meat Science, 96(2), 1076-1087.
Pethick, D. W., Banks, R. G., Hales, J., & Ross, I. R. (2006). Australian prime lamb – A vision for 2020. International Journal of Sheep and Wool Science, 54(1), 66-73.

Genetic trade-offs between lamb and wool production in Merino breeding programs

Johan Greeff
Department of Primary Industry and Regional Development, 3 Baron Hay Court, South Perth, Western Australia
Author correspondence: johan.greeff@agric.wa.gov.au

Abstract

Merino breeding programs generally focus strongly on the wool production traits.  However, selecting only for increased wool production can result in undesirable responses because of the negative relationships that exist between wool production and the reproduction traits. Thus breeding programs should be more balanced and should aim to improve both meat and wool production traits simultaneously.

Introduction

The Merino has mainly been selected for wool production for a very long time. Research carried out at Katanning research station showed that there was genetically a negative relationship between fleece weight and ultrasound fat depth in hogget Merinos (Greeff et al. 2006; Adams et al. 2007). This implies that if selection is aimed at improving wool production, then the Merino will get leaner over time.  

During the last decade genetic improvement of the Merino shifted towards a more dual purpose type of sheep in Western Australia.  Other research has shown that there was a negative genetic relationship between number of lambs weaned and fleece weight that varied from minus 0.10 to minus 0.49 (Safara and Fogarty, 2003). Thus we postulated that if a negative relationship in hogget ewes also hold in mature ewes, then the heavier wool producing ewes would be leaner, having less reserves and more likely to wean less weight of lambs than ewes that produce less wool. 

We investigated these relationships in the Katanning base flocks. The data were collected on mature ewes from six different Merino strains from 1986 to 1993. The flock consisted of approximately 1800 mature ewes which were run and managed in four separate management groups.   

The ewes were extensively measured for wool, growth and the reproduction traits over their lifetime. In this analysis we used adult ewe live weight (ALWT) at mating and adult clean fleece weight (ACFW). Clean fleece weight was corrected for litter size and for sex of the lamb. We expressed the wool production potential as the percentage of wool produced per kilogram of live weight (ACFW/ALWT), and this was plotted against wool production potential for six different Merino strains. 

Results

The figure below shows the kilograms of lamb weaned per ewe mated plotted against wool production potential (ACFW/ALWT) for the six different Merino strains.

It is clear that apart for strain 6, which was a superfine wool strain, there was a remarkable negative linear relationship between meat production and wool production potential for strain 1 to 5. This indicates that strains with high wool production potential will tend to produce less lambs than strains with a lower wool production potential. The fine wool strain is clearly an outlier and according to the trend line it should have had a higher reproduction rate. However, closer examination of the data also showed that this strain had a lower fertility, litter size, survival rate and growth rate up to weaning compared to the other groups. As fibre diameter is positively correlated to reproduction rate, this implies that selecting for reduced fibre diameter resulted in a lower reproduction rate.

These results support the research by Herselman et al. (1998) who concluded that fitness may be compromised in animals with a high potential for fibre production. However, it is important to realise that these results do not mean that selecting for increased fleece weight and finer wool should or will have an inevitable negative impact on reproduction rate. Nevertheless, although this negative relationship exists, the actual genetic relationships between these traits are not very strong and the relationships can be bent by using breeding values. Breeding values for reproduction and fat reserve traits were not available at the time when these sheep in this experiment were selected for increased wool production. As reproduction rate and its components are heritable and usually have a high variation, they can be improved by selecting directly for number of lambs weaned in ewes or using scrotal circumference in rams as an indirect trait. Sheep Genetics has an extensive database on breeding values for a wide range of traits. These breeding values can be used to improve both fleece weight and the reproduction traits simultaneously. Breeders are therefore strongly encouraged to use these breeding values to ensure that reproduction rates will not deteriorate while selecting for increased production.

Conclusion

Breeding programs should focus on all the economically important production traits and not focus only on a few specific traits. This implies that the breeding goals of the Merino should be broadened to increase both meat and wool production. Breeding values of a wide range of economically important traits are available from Sheep Genetics to assist breeders to identify genetically superior sheep without sacrificing fitness or reproduction while selecting for increased meat and wool production.

References

Adams NR, Briegel JR and Greeff JC (2007). Responses of wool growth rate and body reserves to nutrition in Merino ewes: a potential biological link between production and fitness. Aust. J. Agric. Res. 58, 913-920.
Greeff JC, Cox G, Butler L, Dowling M (2005). Genetic relationships between carcass quality and wool production traits in Australian Merino rams. Proceedings of the Association for the Advancement of Animal Breeding and Genetics 16, 12–15.
Herselman MJ, Olivier JJ and Snyman MA (1998). Studies on small ruminant breeds with inherent differences in fibre production and ewe productivity. 1. Relationship between ewe productivity and wool production potential. S. Afr. J. Anim. Sci. 28, 1-8.
Safara A, and Fogarty N.M. (2003). Genetic parameters for sheep production traits. Technical Bulletin 49 NSW Agriculture.

Breeding to produce high clean fleece weight decreases fat reserves in pregnant and lactating Merino ewes and is likely to reduce their reproductive success

T. Clarke^A, J.C Greeff^B, I. Williams^C
AWestpork Pty Ltd, Maylands, WA 6051 Australia
^BDepartment of Primary Industries and Regional Development, South Perth WA 6151
^CThe University of Western Australia, Crawley WA 6009
Author correspondence: taya.clarke@westpork.com.au

Introduction

Breeders of Merino sheep have placed heavy emphasis on the production of a high clean fleece weight (CFW).  The trade-off, however, is the negative correlation between high CFW and fat depth (Greeff et al, 2008) as well as a negative genetic correlation between high CFW and the number of lambs weaned (Safari et al, 2005).  A higher CFW means more metabolically active follicles in the skin, syphoning energy away from the body reserves.  The effect of pregnancy and lactation on the body composition (fat and lean) has not been investigated in Merino sheep.  Since ewes with a high CFW are expected to have a higher metabolic demand compared to ewes with a low CFW, it was hypothesised that ewes with a high clean fleece weight would have less fat and higher lean body mass in late pregnancy and throughout lactation compared to ewes with a low CFW.

Method

Duel Energy X-Ray Absorptiometry (DXA) was used to determine the body composition (gram lean tissue mass and % fat) of ewes n=146 Merino ewes selected based on their extremes in the estimated breeding values (EBVs) for clean fleece weight. Ewes were inseminated with semen from Border Leicester, Merino or Terminal sires at the same time. All of the ewes had reasonably similar EBVs for hogget body weight and fibre diameter.  Dry (n=39), single (n=52) and twin (n=55) bearing ewes were selected from these high (n=84) and low (n=64) clean fleece weight groups and managed in the same group for the duration of the experiment. Ewes, including dry ewes, were weighed and scanned at 75-80 days pregnant, at 21 and 42 days of lactation. The DXA output were analysed by repeated measures single variate ANOVA with ewe number, ewe age, selection group (high or low clean fleece weight), lambs (dry, single or twin), sire breed and scanning time set as fixed factors.

Results

High clean fleece weight ewes had less fat reserves irrespective of whether they were dry or pregnant with single or twin lambs. A significant interaction (P=0.026) was found between selection for clean fleece weight and scanning time (Figure 1). The pregnant ewes lost fat reserves consistently over the experimental period, with the twin bearing ewes losing more fat while the dry ewes gained fat from 21 days to 42 days.

The results support the hypothesis that sheep selected to produce a high clean fleece weight have fewer maternal fat reserves throughout pregnancy and lactation. The results suggest that breeding programs for increased wool production should also include selection to increase fat reserves as part of the breeding objective. Pregnant and lactating ewes also require supplementary feeding during late pregnancy and lactation to maintain body condition to ensure that milk production and reproductive success are not compromised.

References

Greeff, J. C., Safari, E., Fogarty, N.M., Hopkins, D.L., Brien, F.D., Atkins, K.D., Mortimer, S.I. and van der Werf, J.H.J. (2008). "Genetic parameters for carcass and meat quality traits and their relationships to liveweight and wool production in hogget Merino rams." Journal of Animal Breeding and Genetics 125(3): 205-215
Safari, E., Fogarty, N.M. and Gilmour, A.R. (2005). "A review of genetic parameter estimates for wool, growth, meat and reproduction in sheep." Livestock Production Science 92: 271-289

Special thanks to the Australian Wool Education Trust for helping fund this work.

Case Study: Weaning Management

Emily Stretch, Stretch Enterprises, Kojonup WA
Author correspondence: emilystretch@hotmail.com

Context

We run between 12 000 and 18 000 merino sheep in any given year. Generally, our breeding ewe flock is 5000 head. We join our maiden ewes at 1.5 years of age. We have a finer wool genetic base with slower body growth than maternal and crossbred sheep. We let our sheep grow out on a gradual rising plane; we don’t need our sheep to push a really high growth rate as we don’t join ewe lambs. The wethers are kept on the farm for a few years to give us flexibility in tight winters, or extremely wet winters, being the first sold when Feed on Offer (FOO) is low. The rest of the flock consists of bought wethers, weaners, and hoggets. Our cropping system ranges from 1,200 hectares (when running 18 000 sheep) to 1800 hectares (when running 12 000 sheep). We join in mid-February and lamb from mid-July to the end of August. We aim to wean anywhere from 20 October to 10 November. We generally start harvest around the 1 December, give or take a week, and like to have the weaners settled by then so that we can focus on harvesting. 

Weaning in a nutshell

We wean an approximate 3700 lambs onto one of two paddock types; standing oat fodder, or kikuyu, clover and ryegrass. We leave around one ‘leader-ewe’ to every 100 lambs weaned (or enough ewes to make up a full bale of wool at weaner shearing in April). The weaners get their booster vaccination, a drench (if required after a worm egg count), and Clik to protect from flies. The standing oat crops create an ecosystem where flies can thrive; the wind doesn’t always penetrate the oats to dry the weaners off.

Our ideal weaning scenario: 

We settle the weaners for 1-2 days with hay and water in the sheep yards or small holding paddocks with secure fences. We then drive them gently out to their kikuyu paddock (our preference) or standing oat paddock (if a kikuyu paddock is not established on that part of the farm). We move them ALL to the water point in that paddock and hold them there until they start to drift off and graze. We have dams in almost every paddock; if we were working with troughs we would hold them for longer on the water point to ensure that everything has had a drink. We then leave them alone until the next morning, in which time they will undoubtedly walk the length of the entire fence. We check on them at 8-9am, about when adults would typically walk to water points. Regardless of the leader-ewes’ ability to do their job, some weaners are always separate from the mob; there will be a group standing in full sun, or one with its head caught in a fence, or one cast against a log. We bring all the animals back to the watering point, let them drink and then shift them to shade in the morning. In the afternoon we pick them up from shade at 3-4 pm, take them to the watering point and then let them graze. We do this every day for the first week. Then we check once a day for the second week, once every two days for the third week, and finally tapering off into a weekly check that tends to coincide with a supplementary feed. In standing oats, this job is far more intensive as the oats act as a natural barrier that they don’t want to walk through. They also have trouble seeing each other, which means they bunch into little pockets instead of a big mob.

Our feed supplementation strategy is based on metabolisable energy (ME) requirements (available via the LTEM: Lifetime Ewe Management app and DPIRD’s Supplementary Feeding and Feed Budgeting for Sheep). We make sure that we have lupins on hand for increased protein intake, as well as harvested oats for the autumn period when available roughage is limited. We budget on feeding from December to mid-June for the weaners and mid-January to mid-June for the adult flock. On a basic level, we make sure weaners have a feed ration with 15% protein and more than 10 megajoules (MJ) of energy per day. Oats alone don’t meet the protein requirement, so we supplement with lupins. The lupins also help increase the ME eaten with a smaller volume of feed ingested. 

The general rules for our weaner rations are:

• Allow for rumen adaptation to the oats for the first three to four weeks.
• Start supplementary feeding lupins in a trail to introduce them to the feed @ 50g/head/day.
• Increase the feed rate by 25g/head/day every two weeks. This is variable depending on feed available in the paddock.
• Once they are accustomed to the grain and the feed being brought into the paddock, we use a spreader at a 4-6m width and broadcast the lupins through the oats. This encourages them to pick up the oat grains off the ground as well.

Standing oat fodder

Why do we do it? 

• We don’t strive for a massive growth rate, just a steady one.
• We’re busy harvesting from December to mid-January.
• It’s a simple way to make sure that the animals have their base ration of feed.
• When managed correctly, they pick up little to no worms, which increases their chances of consistent growth rates.
• The weaners are in confined areas for checking.
• The adults can get the most out of the stubbles which our weaners tend to lose weight on as they walk a long way to pick up a smaller amount of grain.
• Fodder crops are clean of grass seeds (when managed correctly through winter).
• It often looks expensive on paper, but the simplicity of the management system while we are busy elsewhere is hard to measure.

How do we grow it?

We grow these paddocks as if they were commercial oat crops to achieve the most grain and biomass yield possible. If we didn’t have fodder paddocks, we would be harvesting grain or buying grain in to feed them.

We make sure that we have at least one paddock of oats on each block of land to make weaning simple. We try to seed 100 hectares for the weaners in small paddocks or areas of paddocks that oats thrive on and where canola and other cereals don’t. These paddocks may also have grass issues and they generally become pasture the following year, so any regrowth oats or grasses aren’t an issue. They can be tough to manage if they need to go into crop the next year due to stubble retention. Running adult sheep over them after the weaner mob helps to smash the stubble down and make sure all of the grains are picked up off the ground.

We manage our fodder paddocks the same as our cropping program. They get a full knockdown spray, seeded at 100kg/ha, fertiliser down the tube at 100kg/ha. We spray and spread as normal throughout the season, with an added selenium chip spread with the first urea pass. Historically we know that our soils are deficient in selenium. We try to use a shorter variety of oats like Mitika as the weaners stand a chance of seeing over it. All of our soil testing, tissue testing, and liming happens as normal within our rotation. These aren’t sacrificial paddocks; we make them work hard so that the weaners can benefit from them.

How do we manage it?

At haying off the oat fodder paddocks get a hay cut or harvest run around the fences and to the water point from multiple directions. These paths give weaners access routes to follow to water, and space to walk the fence without pushing on it. It also gives us a safe place to drive or ride through the paddock with less fire risk from vehicle exhausts. It also helps when you push weaners into the paddock for the first time as they don’t hit a wall of oats and stop moving. If the paddock is larger than 30 hectares we look at putting in a temporary fence so they don’t trample the whole paddock walking kilometres to water.

The fodder paddocks are hayed off naturally and weaners are drenched onto these paddocks at this time. We could spray-top to move this forward for a weaning timeline but haven’t needed to so far. On the blocks where we have kikuyu paddocks established, the weaners head there first which enables an earlier weaning. Our weaner drenching management plan for the fodder crops is that we don’t leave any refugia animals to ensure optimal growth for all. After the weaners have moved off that fodder paddock we run an undrenched mob of adults over the paddock to dilute the worm population to minimise breeding drench resistant worms. Alternatively, we can leave the leader ewes undrenched and monitor closely with egg counts especially if there is summer rain.

Weaners are stocked at 25 DSE/ha to 50 DSE/ha, with a maximum mob size of 1000 head. Calculating the grain production alone, a 30ha paddock of oats yielding an average of 3t/ha has 90 000kg of oats available. From feed tests, this 90 000kg of oats equates to a total of 963 000 MJ of energy, which gives 1000 weaners nearly 100 days of grazing that started at a bodyweight of 30kg and are maintaining a 50g growth rate per day. The table below gives some guidelines on daily energy requirements for medium-frame weaner sheep on different growth rates. 

Then there is the biomass of the oat itself. Our weaners graze the whole Mitika plant which lengthens the time frame for grazing. However, we do our feed budgeting on the grain portion alone to ensure that we have adequate feed reserves. The lupin supplement for protein also prolongs the length of grazing as they don’t have to eat the oats at that rate to meet their ME requirement.

Paddocks are monitored from mid-January onwards for numbers of grain per square foot to ascertain when the animals need to shift to their next fodder paddock, or when to increase their supplementation with an oat ration as well. If the paddock gets too bare, we shift them onto a pasture base or different stubble to minimise erosion.

NB. Insurance on standing fodder can be a grey area and needs defining with your insurance agent. Also keep in mind, animals in standing fodder are in a high fire risk environment.

Kikuyu paddocks 

Why do we do it?

• Kikuyu paddocks tend to hold together sandier soil profiles and reduce erosion in wind and rain events.
• Acts as a summer feed base while providing a vitamin E boost.
• Grows in areas where we struggle to keep other species persisting.
• Once it’s established it is easier to keep clover and rye persisting through it in winter due to reduced soil profile damage in summer.
• We don’t seed paddocks every year; our last paddock was around 10 years ago. We are looking to establish some more in the next two years because we now understand how to utilise these paddocks in our soil and livestock systems.

How do we grow it?

Kikuyu paddocks have been established with similar timing and systems to normal pasture seeding. We use our normal seeding gear and sow during autumn or spring when it’s warmer. The paddocks require prior manipulation/spray control to allow the kikuyu to get established. This year we have seeded a problem area to oats which gives us the knockdown and broadleaf control through winter. We will then spray it out and graze or cut it for silage in spring. After that, we should have a clean paddock for kikuyu establishment.  

These paddocks do require careful grazing. Livestock will pull the rhizomes straight out of the ground if they are allowed to graze it too early or to the ground. We graze to a golf ball height with sheep and a cricket ball height with cattle. While it’s being established, keep sheep, kangaroos, rabbits and any other animals off the paddock. 

During winter we can graze the paddocks as per normal. As long as there are good growing conditions, the winter pasture tends to grow above the kikuyu meaning the animals can’t overgraze it. This also keeps the kikuyu from getting rank or thatching. We lock these paddocks up in late August to allow the winter feed base to bulk up and to minimise the worm burden. As temperatures warm up, the kikuyu begins to grow up through the winter feed base. When we wean onto it they get a mixture of clover, rye and green grass to build up their vitamin E bank. 

We haven’t needed to reseed kikuyu in the paddocks that have established well. Kangaroos are a significant issue for getting these paddocks going and keeping them persisting. We will need to maintain a reseeding schedule for the clover and rye in these paddocks as the weaners deplete the seed bank each year. For this purpose, a disc seeder is used during autumn over the kikuyu to replenish clover and ryegrass seed numbers.    

How do we manage it?

Weaners go out onto these paddocks anywhere from 20 September to 10 November. Depending on the year the annual pastures can be green at this time or haying off. Quite often we won’t drench weaners onto these paddocks. We monitor their worm burden with egg counts before weaning. If they are over 75-100 eggs per gram, we drench them onto the paddock to keep them growing well. If they are under this threshold, we monitor them closely and potentially just drench the light or weedy animals at weaning. When the weaners come off the kikuyu paddock and head for standing oats, they get a drench. The oat paddock is worm free. If the weaners don’t take worms in, they’ll stay healthy for longer. We don’t always drench onto the kikuyu paddock as we know they’ll be getting one in 3-6 weeks. These paddocks have a solid pasture height which reduces worm egg intake as well, however these paddocks may have worms the whole way through summer due to the persistent green feed. 

If it rains during summer, we will bring the weaners back to the kikuyu paddocks every 6-8 weeks to bring their vitamin E levels back up. If there’s no growth in the paddock and grazing would be detrimental, we’ll look at using a vitamin E drench or grain treatment instead. Once they have been back on the green feed, we monitor for worms closely by using faecal egg counts.

Other management techniques

• Training feeds with multiple grains – before weaning, we introduce the feed cart to the mob. We use the ewes to teach the lambs to come to the feed cart and to pick up grain from a trail. We feed them at least twice with oats and twice with lupins to start some rumen adaptation. The rumen adjustment period after weaning can temporarily reduce growth rates, so we start that adjustment before they have the additional stress of weaning. 
• Yard, trough and shed training – at lamb marking and weaning we introduce the lambs to as many different things as possible while they have their mothers to teach them. It makes life easier for them and us over their lifespan.
• We also allow our sheep to exit or calmly walk through high stress areas such as drenching races or truck load out areas.

The fodder crops and kikuyu pastures have worked extremely well in our enterprise.  Feed budgets and worm thresholds will vary depending on your flock, breed, climate and many other factors. It is important to do your research based on your animals and enterprise!