scholarly journals Whole-farm profit and the optimum maternal liveweight profile of Merino ewe flocks lambing in winter and spring are influenced by the effects of ewe nutrition on the progeny's survival and lifetime wool production

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.

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.


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.


1979 ◽  
Vol 27 (5) ◽  
pp. 813 ◽  
Author(s):  
TE Woodward

The lethaeine genus Austroxestus Woodward, 1962, and its type-species A. carnarvoni Woodward are redescribed. The type locality of this species is the Carnarvon Range, Queensland; new records are from eastern New South Wales. The following are described: A. australiensis, sp. nov., from Tasmania, Victoria and eastern Queensland, A. taylori, sp. nov., from New South Wales, and A. westraliensis, sp. nov., from south-west Western Australia. The variation and distribution of A. australiensis are discussed. The four species are keyed out.


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.


2006 ◽  
Vol 28 (1) ◽  
pp. 97 ◽  
Author(s):  
D. E. Peacock

The numbat (Myrmecobius fasciatus ) was formerly widespread across most of southern Western Australia, South Australia and western New South Wales. It delined in the early 1900's, possibly due to foxes, cats, or an epizootic. Protection through control of foxes and cats, and translocation, has resulted in several populations being re-established at sites of historical distribution.


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.


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.


1982 ◽  
Vol 30 (3) ◽  
pp. 461 ◽  
Author(s):  
JA Friend

Descriptions of two new genera including five new species of Australian landhoppers are presented. Two new species are recorded from south-west Western Australia (Austrotroides pectinalis and A. occidentalis) and one each from the Adelaide area (A. crenatus), southern Victoria (Agilestia hyperocha) and southern Queensland-northern New South Wales (A. hylaea). Notes on the life history of Austrotoides crenatus are provided.


1992 ◽  
Vol 5 (1) ◽  
pp. 1
Author(s):  
RJF Henderson

The genus Amperea Adr. Juss. contains eight species, six of which are confined to the south-west of Western Australia. The seventh occurs only in central Australia while the eighth ranges from central Queensland to Tasmania and extends to the south-east of South Australia. A. simulans, from Western Australia, is described as new, and A. xiphoclada var. papillata and A. xiphoclada var. pedicellata from New South Wales are recognised as new varieties; A. xiphoclada var. pedicellata is probably now extinct. Lectotypes are chosen for A. micrantha and A. volubilis. All species are described in detail and a key to identify them is provided. The diagnostic relevance of a range of attributes of the genus is reviewed as is its classificatory history.* The first of a projected series of revisions of genera traditionally included in Stenolobeae Benth., and others related to them, which are intended to form the basis of future Flora of Australia accounts.


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