Wool production, ground cover and botanical composition of pastures grazed by Merino wethers in central western New South Wales. 1. Natural pasture

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.


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.



1972 ◽  
Vol 12 (59) ◽  
pp. 584 ◽  
Author(s):  
WR McManus ◽  
TG Kennedy

Merino ewe weaner lambs grazing at a high stocking rate for 32 weeks in the Wellington region of New South Wales were fed two levels (low, medium) of oat grain plus lucerne hay supplement. Insignificant fleece-adjusted liveweight gain and significant, but small, (2.8 per cent and 9.9 per cent) increases in clean fleece weight resulted for the low and medium groups. Feeding reduced fleece tenderness and altered wool handle and colour. Merino weaner ewes grazing improved pastures at Yass were supplemented with oat grain for 12 weeks in the late summer-early autumn. There was a temporary increase in woo1 production and liveweight but subsequent fertility was not improved. The responses obtained to treatment in both trials appear to be uneconomic



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.



1985 ◽  
Vol 7 (2) ◽  
pp. 88
Author(s):  
GG Robinson ◽  
PM Dowling

Pasture and animal production from fertilised pastures with varying proportions of sown grass (0-60%) were recorded and compared. The presence of sown grass increased pasture production when compared to natural pasture, but no difference was detected in liveweight or wool production between the var- ious pastures. It is doubtful whether sowing of introduced grasses for wool production can be justified at the levels of grazing intensity usually adopted on the Northern Tablelands.



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.



1973 ◽  
Vol 13 (64) ◽  
pp. 510 ◽  
Author(s):  
H Brownlee

Two grazing experiments were performed between 1965 and 1969 at the Agricultural Research Station, Condobolin, to determine the carrying capacity of Jemalong barrel medic (Medicago truncatula) pasture. In each experiment the pasture was set stocked with Merino wethers at 3.1, 4.1 and 6.2 ha-1. An additional treatment stocked at 6.2 ha-1 was included in which two-thirds of the pasture area was saved during autumn or periods of feed shortage while stock were confined to the other one-third. In both experiments the pasture supported 3.1 wethers ha-1 under set stocking for three years with little supplementary feeding and regenerated successfully each year. No major changes in botanical composition were recorded, and Jemalong medic remained the major component of the pasture. Autumn saving at 6.2 ha-1 mitigated the effects of the high stocking rate on both animal and pasture, but did not result in worthwhile animal production increases.



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.



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.



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.



1974 ◽  
Vol 14 (71) ◽  
pp. 726 ◽  
Author(s):  
GT McKinney

Eight whole-farm systems of managing lucerne pasture were compared at one high (near optimum) stocking rate of breeding ewes. These systems were continuous grazing (C), a 2-paddocks (2P), two 3-paddocks (3P), three 6-paddocks and one 12-paddocks rotations. Pasture density, yield and composition were almost solely dependent on spelling time. Maximum lucerne density was maintained when spelling times averaged more than 50 days over the year. Near maximum contributions of annual grasses were achieved when spelling times were less than 45 days. Therefore, to optimize persistence of important pasture components a 'minimum spelling time' policy is suggested. This time ranges approximately from 53 weeks in summer to 8 weeks in winter. Animal production appeared to depend on botanical composition and the extent to which lucerne stem was allowed to develop. Where lucerne failed to persist, or spelling times were long, liveweight gain was low over summer. Thus production was lower on C and 12P respectively, than other systems, and 2P and 3P gave the best overall production.



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