Performance of sheep systems grazing perennial pastures. 1. Pasture persistence and enterprise productivity

2020 ◽  
Vol 60 (3) ◽  
pp. 388
Author(s):  
Susan M. Robertson ◽  
John C. Broster ◽  
Michael A. Friend

Sheep production can be optimised by matching the pasture supply curve to feed demand. This study evaluated the production from four management systems with Merino ewes during 2006–2010 in southern New South Wales by using different combinations of lambing time (winter, split, spring), ram breed (Merino, terminal), and percentage of summer-active pasture species (40% or 20% lucerne, Medicago sativa). All systems were stocked at a similar midwinter rate (dry-sheep equivalents per hectare of 8, 10.2, 13, 11.2 and 11.2 in the successive seasons 2006–2010), and there were three replicates of each system. Groundcover and pasture persistence were not adversely impacted by sheep system because sheep were removed at predetermined biomass triggers. Wool production per hectare was up to 178% or 12 kg/ha higher (P < 0.001) in systems where a later month of lambing allowed an increase in number of ewes per hectare at the same midwinter stocking rate. The quantity of lamb sold was not consistently higher in any one system, or in systems producing both crossbred and Merino lambs vs only Merino lambs, owing to variation in the weight and age of lambs at sale, but was increased (P < 0.001) by 175 kg/ha with use of 40% compared with 20% lucerne in a high-rainfall year. The risk of requiring high levels of supplementary feeding was higher in systems with later lambing because of below-average rainfall between 2006 and 2009. Large increases in production can be achieved from the same pasture base through choice of management system with different lambing time, stocking rate or ram breed, but flexibility is needed to optimise production in varying seasonal conditions.


1973 ◽  
Vol 13 (62) ◽  
pp. 238
Author(s):  
RJ Campbell ◽  
DG Saville ◽  
GE Robards

Natural annual pasture at Trangie, New South Wales, was set stocked from August, 1967 to December 1970 at rates of 2.5, 3.7, and 4.9 merino wethers per ha to determine an optimum stocking rate for the pasture type. All stocking rates were supported without the necessity to hand feed any sheep. Wool production per head was reduced significantly by increased stocking rate in 1968, but not in 1969 and 1970. The suppression of barley grass at the higher stocking rates appeared to benefit animal production in 1969. Substitution of portion of the natural annual pasture with areas of lucerne or natural perennial pasture was also investigated and found to be ineffective in increasing wool production per head above that of wethers at similar rates of stocking on natural annual pasture alone. Possible reasons for the apparent failure of the grazing supplements, particularly lucerne, are discussed in terms of grazing pressure and management strategies.



1998 ◽  
Vol 38 (5) ◽  
pp. 433 ◽  
Author(s):  
H. Lloyd Davies ◽  
J. D. McFarlane ◽  
O. L. P. de Oliveira ◽  
G. W. King ◽  
J. W. James

Summary. The effect of 4 rates of superphosphate application (250 kg/ha. year, 125 kg/ha. year, 125 kg/ha every 2 years or 125 kg/ha every 4 years) and a low and high stocking rate (3.6 and 5.4 ewes/ha, 1980–86; and 4.0 and 7.0 ewes/ha, 1986–89) on sheep liveweight, fleece weight, lamb weaning weight, pasture production and botanical composition, soil pH, soil phosphorus, manganese and aluminium concentrations were measured on a Phalaris aquatica–subterranean clover pasture at Stuart Town, New South Wales. Only when 250 kg/ha of superphosphate had been applied annually was there a higher level of soil phosphorus than with the other 3 systems. None of the treatments affected soil pH, soil manganese or aluminium. There were large year effects and individual plot effects on pasture and sheep production but neither the superphosphate rates nor stocking rate significantly affected pasture or animal production. It was concluded that over a 9-year period the application of 125 kg/ha in alternate years can maintain adequate soil phosphorus levels, and satisfactory pasture and animal production on the central tablelands of New South Wales.



1993 ◽  
Vol 15 (1) ◽  
pp. 79 ◽  
Author(s):  
DA Roshier ◽  
I Barchia

Historical sheep production and rainfall data from 14 properties in semi-arid western New South Wales were analysed for relationships between wool production, lamb marking percentage, stocking rate and rainfall. Twelve of the properties were located on predominantly chenopod shrubland (Atriplex spp. and Maireana spp.) and two on mulga (Acacia aneura) land types. The relationship between wool production per head (WOOLHD, kg greasylsheep) and rainfall (RF, mmlyear) was similar on 10 of the 11 properties with wool production and rainfall data. This was so despite differences in vegetation type and average stocking rate. The generality of this relationship suggests that wool production per head is largely determined by a common, rainfall related factor operating over a wide range of management regimes. Stocking rates did not have a significant effect on wool production per head on the majority of properties. Data from the above properties were combined to generate the following generalised equation: -29.43 - WOOLHD = 7.5 lexp RF R~ =35.72 (P<0.01) Wool production per hectare was largely determined by stocking rate on most properties. No consistent relationship between lamb marking percentage and when rain fell could be found. However, rainfall in the period between joining and lamb marking was significant on six properties. It is concluded that total wool production is largely determined by stock numbers. The data suggests animal productivity is more dependent on management responses to dry periods and the rate of change in forage availability in the absence of rain.



2015 ◽  
Vol 66 (4) ◽  
pp. 349 ◽  
Author(s):  
Julianne M. Lilley ◽  
Lindsay W. Bell ◽  
John A. Kirkegaard

Recent expansion of cropping into Australia’s high-rainfall zone (HRZ) has involved dual-purpose crops suited to long growing seasons that produce both forage and grain. Early adoption of dual-purpose cropping involved cereals; however, dual-purpose canola (Brassica napus) can provide grazing and grain and a break crop for cereals and grass-based pastures. Grain yield and grazing potential of canola (up until bud-visible stage) were simulated, using APSIM, for four canola cultivars at 13 locations across Australia’s HRZ over 50 years. The influence of sowing date (2-weekly sowing dates from early March to late June), nitrogen (N) availability at sowing (50, 150 and 250 kg N/ha), and crop density (20, 40, 60, 80 plants/m2) on forage and grain production was explored in a factorial combination with the four canola cultivars. The cultivars represented winter, winter × spring intermediate, slow spring, and fast spring cultivars, which differed in response to vernalisation and photoperiod. Overall, there was significant potential for dual-purpose use of winter and winter × spring cultivars in all regions across Australia’s HRZ. Mean simulated potential yields exceeded 4.0 t/ha at most locations, with highest mean simulated grain yields (4.5–5.0 t/ha) in southern Victoria and lower yields (3.3–4.0 t/ha) in central and northern New South Wales. Winter cultivars sown early (March–mid-April) provided most forage (>2000 dry sheep equivalent (DSE) grazing days/ha) at most locations because of the extended vegetative stage linked to the high vernalisation requirement. At locations with Mediterranean climates, the low frequency (<30% of years) of early sowing opportunities before mid-April limited the utility of winter cultivars. Winter × spring cultivars (not yet commercially available), which have an intermediate phenology, had a longer, more reliable sowing window, high grazing potential (up to 1800 DSE-days/ha) and high grain-yield potential. Spring cultivars provided less, but had commercially useful grazing opportunities (300–700 DSE-days/ha) and similar yields to early-sown cultivars. Significant unrealised potential for dual-purpose canola crops of winter × spring and slow spring cultivars was suggested in the south-west of Western Australia, on the Northern Tablelands and Slopes of New South Wales and in southern Queensland. The simulations emphasised the importance of early sowing, adequate N supply and sowing density to maximise grazing potential from dual-purpose crops.



1988 ◽  
Vol 28 (5) ◽  
pp. 561 ◽  
Author(s):  
HL Davies ◽  
E Devaud

A March-April joining of Merino ewes was compared with a June-July joining in central New South Wales at a low stocking rate on subterranean clover based pastures over 3 years. In all years, ewes joined in June were heavier (P < 0.05) than ewes joined in March (55 v. 52 kg). Liveweights at the start of lambing and liveweight change from joining to lambing were also high and favoured the later lambing group. The proportion of ewes lambing (97% March v. 93% June) and proportion of ewes twinning (29% March v. 20% June) were not significantly different between the 2 groups, but consistently favoured the March-April joining. Perinatal mortality was low (9.4% March v. 7.1% June) and not significantly different between the 2 groups, but was consistently lower in the June joined group. Number of lambs weaned per 100 ewes joined was also not significantly different, but was higher each year in the March joined group (1 13% March v. 105% June). The growth rate of the lambs (both singles [24% greater, 248 v. 200 g/day] and twins [37% greater, 2 13 v. 155 g/day]) was consistently in favour of March joined ewes. Mean greasy fleece weights of the ewes were not significantly different between the 2 groups, but were in favour of the late joined group (4.83 v. 4.50 kg). Time of joining significantly affected liveweights and greasy and clean fleece weights of the progeny at the shearing in the year following their birth in favour of March joining. These data suggest that, despite a nutritional advantage to the ewes in late pregnancy and milder weather at lambing with a June-July joining, a March- April joining is the preferred option on the Central Tablelands of New South Wales.



1995 ◽  
Vol 35 (1) ◽  
pp. 93 ◽  
Author(s):  
RD FitzGerald ◽  
ML Curll ◽  
EW Heap

Thirty varieties of wheat originating from Australia, UK, USA, Ukraine, and France were evaluated over 3 years as dual-purpose wheats for the high rainfall environment of the Northern Tablelands of New South Wales (mean annual rainfall 851 mm). Mean grain yields (1.9-4.3 t/ha) compared favourably with record yields in the traditional Australian wheatbelt, but were much poorer than average yields of 6.5 t/ha reported for UK crops. A 6-week delay in sowing time halved grain yield in 1983; cutting in spring reduced yield by 40% in 1986. Grazing during winter did not significantly reduce yields. Results indicate that the development of wheat varieties adapted to the higher rainfall tablelands and suited to Australian marketing requirements might help to provide a useful alternative enterprise for tableland livestock producers.



1980 ◽  
Vol 20 (102) ◽  
pp. 25
Author(s):  
RDH Cohen

Lamb production was studied in an experiment that ran for four years, 1968 to 1972, at Grafton, New South Wales, in a region where no commercial sheep are grown. Merino and Dorset Horn x Merino ewes stocked at 15 ewes ha-1 were mated in spring to Border Leicester rams and the lambs sold for slaughter in October. The mean number of lambs born per 100 ewes mated was 81.7 for crossbred ewes and 48.4 for Merino ewes (P< 0.05) and the mean carcase weights of the lambs were 14.8 kg and 12.7 kg, respectively (P< 0.01). The mean weight of fleeces cut from Merino ewes (3.24 kg) was greater (P< 0.01) than that from crossbred ewes (2.58 kg). The ewes were treated with anthelmintics either every four weeks or according to climatic conditions. There were no significant differences between the anthelmintic treatments for lamb liveweights at birth, weaning or slaughter; carcase weight; ewe fleece weight; or mortality rate. Treatment every four weeks increased ewe live weight during only one short period from August 1971 to February 1972 (P< 0.05). Data from this experiment compared favourably with survey data for the high rainfall zone in Australia and it was concluded that prime lamb production on the north coast of New South Wales is biologically feasible.



2016 ◽  
Vol 56 (9) ◽  
pp. 1533 ◽  
Author(s):  
D. M. Nogueira ◽  
B. Gummow ◽  
C. P. Gardiner ◽  
J. Cavalieri ◽  
L. A. Fitzpatrick ◽  
...  

An interview-based questionnaire survey was conducted on 31 goat properties in New South Wales and Queensland in 2013. This study has gathered information on goat herd management, reproductive performance and animal health, and has identified constraints that may limit goat productivity. Producers from high-rainfall regions reported having full blood Boer goats for stud breeding. In contrast, producers from pastoral regions had rangeland goats and Boer-cross goats. Overall, 87% of the producers identified a natural breeding season in goats and 61% separated kids from their mothers at weaning. The weaning age varied between 3.0 and 6.0 months. A total of 52% of producers castrated male kids. Only 10% of producers used ultrasound to conduct pregnancy diagnosis on their goats. The reported pregnancy rate was 60% for the pastoral regions and 94% for the high-rainfall regions. The average prolificacy was 1.4 kids/doe and the kidding interval was 12 months. Overall, 68% of producers fed their goat herd with supplements, with the exception that most producers from western New South Wales and south-western Queensland did not use supplements. Producers considered gastrointestinal parasites (61%) and body lice (48%) as the main diseases associated with their goat herds, although only 52% mentioned drenching the animals with anthelmintics. In general, properties in the pastoral regions showed low pregnancy and kidding rates, early age at first mating, high mortality rates, poor performance of Boer bucks and lower weights and weight gain compared with properties in the high-rainfall regions. The survey has highlighted areas that require further study to validate the observations of producers, for instance, factors that may be limiting the fertility of Boer goats in rangeland environments, the incidence of diseases, the use of Kidplan and management activities to improve goat productivity.



2014 ◽  
Vol 54 (10) ◽  
pp. 1625 ◽  
Author(s):  
S. R. McGrath ◽  
J. M. Virgona ◽  
M. A. Friend

Slow pasture growth rates during winter limit the potential gross margins from autumn and early winter lambing in southern New South Wales (NSW) by limiting stocking rates and/or increasing supplementary feed requirements. Dual-purpose crops can reduce the winter feed gap in mixed-farming systems by increasing the available feed in winter. The simulation software AusFarm was used to model a mixed-farming system at Wagga Wagga with Merino ewes joined to terminal sires and grazing lucerne-subterranean clover pasture over a 41-year period. A paddock of dual-purpose wheat was then added to the system, and ewes were allowed to graze the wheat crop when feed on offer reached 850 kg DM/ha and before GS31. Weaned lambs were sold after late August if lamb growth rates fell below 20 g/head.day, mean lamb weight reached 45 kg or production feeding of lambs was required. Lambing in June resulted in the highest median gross margin whether or not ewes were able to graze the wheat crop during winter. Grazing of a dual-purpose wheat crop resulted in greater proportional increases in gross margins as stocking rate was increased, increased lamb production and reduced supplementary feeding costs, and reduced interannual variability in gross margin returns.



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