Relationships Between Sheep Production, Stocking Rate and Rainfall on Commercial Sheep Properties in Western 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.

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.


1975 ◽  
Vol 15 (75) ◽  
pp. 475 ◽  
Author(s):  
H Brownlee ◽  
BJ Scott ◽  
RD Kearins ◽  
J Bradley

Merino ewes at 3.7, 4.9 and 6.2 ha-1 grazed dryland lucerne (Medicago sativa cv. Hunter River) topdressed annually with superphosphate at 0, 125 and 251 kg ha-1, from September 1969 until December 1972, in an experiment at Condobolin, New South Wales. Superphosphate increased ewe liveweights, total forage available and phosphorus content of the forage by a small amount but did not increase wool production per head. The Bray soil phosphorus test in the top 8 cm of the soil profile rose from 8 p.p.m. to 48 p.p.m., but most of the phosphorus was concentrated in the 0-4 cm layer, where we consider that dry conditions reduced its availability to the lucerne. As stocking rate increased, ewe liveweights and wool production per head decreased and the sheep required more handfeeding for survival. The treatment with the greatest gross margin was the lowest stocking rate with nil fertilizer.


2011 ◽  
Vol 51 (9) ◽  
pp. 821 ◽  
Author(s):  
J. M. Young ◽  
A. N. Thompson ◽  
M. Curnow ◽  
C. M. Oldham

Profitability of sheep production systems in southern Australia is optimised at a stocking rate that provides adequate nutrition for breeding ewes and enables efficient utilisation of grown pasture and supplements. In this paper we used bio-economic modelling to develop optimum liveweight1 profiles for spring-lambing Merino ewes in different environments. The modelling included the impacts of the ewe liveweight profile on the production of the ewe and the survival and lifetime wool production of her progeny. Fifteen ewe liveweight profiles were analysed for each region to determine the profitability of varying ewe liveweight at joining, varying rate of loss of liveweight after joining and the rate of gain in liveweight from the minimum to lambing. The analyses support the hypotheses that whole-farm profitability is sensitive to the liveweight profile of Merino ewe flocks and that there is a liveweight profile that maximises whole-farm profit. The variation between the most and least profitable ewe liveweight profile was $69 0002 per farm ($14.30/ewe) for south-west Victoria, $51 000 per farm ($8.70/ewe) for Great Southern Western Australia and $33 300 per farm ($9.70/ewe) for southern New South Wales. The changes in profit were due to differences in costs of feeding to achieve the ewe liveweight profile and its influence on the production of both the ewes and their progeny. Failure to include the impacts of liveweight profile on progeny survival and lifetime wool production incorrectly identifies the optimum ewe liveweight profile and provided inaccurate estimates of profitability. The optimum liveweight profiles for ewes lambing in spring were similar for all three regions and insensitive to changing commodity prices, pasture productivity and management. The optimum profile was to join ewes at ~90% of the standard reference weight of the genotype, lose a small amount of weight after joining and regain weight in late pregnancy to return to the joining weight by lambing. Regaining the liveweight lost in early pregnancy by lambing is the most important target to achieve. The cost per farm of missing this liveweight target by 1 kg was $13 000 ($2.60/ewe) for south-west Victoria, $8900 ($1.45/ewe) for Great Southern Western Australia and $5500 ($1.65/ewe) for southern New South Wales. By contrast, the cost per farm of missing the joining target by 1 kg was $5500 for south-west Victoria and less than $2000 across the other two regions. Whole-farm profit increased with increasing stocking rate up to an optimum and regardless of stocking rate there is an additional opportunity to increase whole-farm profit by up to 15% by managing ewes to achieve the optimum liveweight profile. This indicates that the optimum liveweight profile should be achieved by increasing the level of grain feeding and altering the timing of utilising the farm feed resources rather than manipulating stocking rate.


1972 ◽  
Vol 12 (56) ◽  
pp. 247 ◽  
Author(s):  
RDH Cohen ◽  
RD Eastoe ◽  
IK Hotson ◽  
MG Smeal

Merino wethers grazing unfertilized pastures in rotational and continuous grazing systems on the North Coast of New South Wales were drenched at high, medium and low frequencies. Liveweights, wool production, faecal nemarode egg counts of the sheep and deaths from helminthosis were recorded. The results indicate that high stocking rates and good wool production can be maintained with frequent drenching. Haemonchus sp. and Trichostrongyh sp. were the most important nematodes that infected the sheep and the epidemiology and control of these two parasites is discussed.


1978 ◽  
Vol 18 (92) ◽  
pp. 361 ◽  
Author(s):  
GE Robards ◽  
DL Michalk ◽  
RJ Pither

A four year experiment is reported during which breeding Merino ewes grazed two natural pasture types at three stocking rates at Trangie in central-western New South Wales. Initially, the pasture on a red brown soil was dominated by cool season annual species, particularly Hordeum leporinum, Erodium species and Medicago species. The pasture on a heavier grey soil was dominated by the perennial grasses Chloris acicularis, C. truncata and Stipa variabilis. Clean wool production of ewes grazing the annual-dominated pasture was significantly (P< 0.05) higher than that of ewes grazing the perennial grass-dominated pasture even though the wool of the ewes grazing perennial pasture had a higher percentage clean yield (P < 0.05). The ewes on the annual-dominated pasture were significantly heavier in autumn and winter, and had a faster rate of wool growth in each season except spring, than ewes grazing perennial pasture. Number of lambs born per ewe, lamb birth weight and lamb growth rate were not affected by pasture type or stocking rate. Stocking rate had a small but statistically significant effect on clean wool production and only small effects on ewe liveweight, regardless of pasture type. When hand feeding of the pregnant ewes became necessary in the poor winters of 1971 and 1972 all stocking rates had to be commenced simultaneously. The significance of perennial grasses in these natural pastures is discussed in relationship to animal production, stocking rate, pasture and soil stability, and regeneration of grasses following favourable seasons.


1976 ◽  
Vol 16 (79) ◽  
pp. 197 ◽  
Author(s):  
OR Southwood ◽  
DG Saville ◽  
AR Gilmour

In an experiment at the Agricultural Research Station, Temora, New South Wales, Merino breeding ewes with their lambs grazed continuously from 1966 to 1970 at three stocking rates, 5, 7.5 and 10 ewes ha-1, on annual Trifolium subterraneum clover pasture topdressed every autumn with superphosphate fertilizer at nil, 94 or 188 kg ha-1. Stocking rate had an effect on ewe body weight in autumn each year and in winter and spring of the last year but it had no effect no wool production per ewe. Apart from the dry year, stocking rate had no effect on lamb performance. Superphosphate had little effect on ewe body weight and none on wool production but there were more lambs on the fertilized treatments than on the unfertilized pastures in 1967 when rainfall was low. Fertilizer encouraged barley grass dominance whereas the pasture not topdressed grew more clover and produced more burr. With no topdressing, available soil phosphate declined steadily over the five years to less than half the initial level. The results indicate that in a spring lambing, Merino ewe enterprise in the southern New South Wales wheat belt, where clover-ley farming is the general practice, annual pasture topdressing is no longer necessary after approximately 1000 kg ha-1 superphosphate has been applied to the soil and the fertilizer is continued through the cropping phase.


1973 ◽  
Vol 13 (64) ◽  
pp. 502 ◽  
Author(s):  
H Brownlee

A natural pasture consisting predominantly of Aristida, Stipa, Danthonia and Chloris was grazed by Merino wethers set-stocked at 2.04, 1.36 and 1.02 ha-1 at Condobolin in central western New South Wales. Throughout the four years 1965 to 1969, the pasture supported 1.36 wethers ha-1 without supplementary feeding. Wool production per ha increased with increase in stocking rate but wool production per head and liveweight decreased. Although there was a greater percentage of annual medics at the high compared with the low stocking rate, the high stocking rate reduced total ground cover and the density of Aristida.


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.


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 &lt; 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 &lt; 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.


1990 ◽  
Vol 30 (3) ◽  
pp. 329 ◽  
Author(s):  
GD Denney ◽  
HI Ridings ◽  
KJ Thornberry

A survey of Merino breeding properties in the Weddin Shire of New South Wales was used to relate the variation in wool production among properties to physical and management factors. Clean wool production averaged 3.15 kg per sheep and showed little variation between the eastern, central and western portions of the shire. However, clean wool production per hectare was greatest in the eastern portion where rainfall, pasture improvement and stocking rate were highest. Overall, ewes produced 88% as much wool as the wethers but variation was great, with 23% of the properties surveyed producing more wool per sheep from their ewes. The difference in productivity for properties in the highest and lowest quartiles was 71% when ranked on clean wool production per sheep. The difference was 184% when ranked on clean wool production per hectare, and even though stocking rate more than doubled, individual productivity increased. Similar differences in quartile production were observed in each portion of the shire. Regression analysis was used to test the importance of 9 physical and 10 management factors as determinants of the variation in clean wool production between properties. Four factors (stocking rate, managerial assessment, sheep strain/bloodline and location within shire) accounted for 74% of the variance in wool production per hectare, but after adjusting for the time of shearing, only 16% of the variance in wool production per sheep was explained. In a more specific analysis of wool production of the properties' ewe flock, 42% of the variance was accounted for by the source of genetic material, stocking rate, pasture improvement, time of lambing, the proportion of Merino ewes and an assessment of managerial ability. Research workers considering on-farm experimentation in wool production should be aware that large productivity differences can occur between nearby properties. Therefore, treatments should be allocated to properties based on known wool production. Further, results obtained from either the ewe, wether or hogget flocks may have application to only that class of sheep because of the large differences in commercial management imposed on them.


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