A comparison of levels of production and profit from grazing Merino ewes and wethers at various stocking rates in northern Victoria

1980 ◽  
Vol 20 (104) ◽  
pp. 296 ◽  
Author(s):  
DH White ◽  
BJ McConchie ◽  
BC Curnow ◽  
AH Ternouth

Merino wethers and breeding ewes were grazed at various stocking rates on an annual pasture in the sheep-wheat zone of Northern Victoria from 1966 to 1973. There was considerable variation between years in botanical composition, the incidence of subterranean clover in the pasture plots varying by up to 80 percentage units between years. Total pasture production was measured in one plot during the last 4 years of the experiment, varying from 2.1 t ha-1 in the drought year (325 mm rain) of 1972, to 8.8 t ha-1 in the higher rainfall (883 mm) year of 1973. The large year-to-year variations in pasture production and botanical composition were reflected in differences between years in sheep production at various stocking rates. Wethers produced about 20% more wool than breeding ewes grazing at the same stocking rate, providing no supplements were fed. August-lambing ewes either lost weight in early spring or gained weight more slowly than wethers of the same age and flock background. The consequence of this was that maximum weights of ewes were consistently about 10 kg less than wethers at the same stocking rate. Both ewes and wethers had similar rates of weight loss from November to March. In one year ewes at 3.7 ha-1 were fed supplements in autumn, since they were lighter than the feeding weight of 41 kg, whereas wethers stocked at 11.1 ha-1, were not. An economic analysis of the experimental data indicated that the most profitable stocking rates of Merino wethers were up to 1.7 times that of August-lambing ewes. This ratio varies with season, and is also likely to vary with changes in lambing date or environment. The most sensitive determinants of optimal stocking rate were the rate of decline of fleece weight, and lambs born relative to ewes joined, with increasing stocking rate. Sheep liveweight at time of sale could also be important.

2006 ◽  
Vol 46 (4) ◽  
pp. 545 ◽  
Author(s):  
H. A. Birrell ◽  
R. L. Thompson

This paper presents work from several studies on pasture production that were conducted in south-west Victoria at the Pastoral Research Institute, Hamilton. The frequency with which pasture growth commenced for each week of autumn in the years from 1965 to 1991 was assessed. The median period for the commencement of growth was in the third week of March (although the average date was March 27). Autumn data from several trials conducted over 3 decades were collated and analysed. A relationship between the grazed pasture yield (average of stocking rates plots) at the end of autumn and the rainfall showed that 200 mm of rainfall in the 3 months to the end of May was optimal while higher rainfall depressed the growth. The average daily growth rates of introduced pasture (perennial rye grass, Lolium perenne L. cv. Victorian, phalaris, Phalaris aquatica L. cv. Australian, subterranean clover Trifolium subterranneum L. and volunteer species) were measured in 2- and 4-week growth periods (G 2 and G 4, kg DM/ha.day) for the seasonal growth cycles over 4 years (1980–84 except 1983) when grazed by Merino wether sheep at stocking rates of 10, 13 or 18 sheep/ha. The rainfall throughout the study was lower than normal. Although differences in the animal performance between the stocking rates were only small, at the low stocking rate capeweed (Arctotheca calendula L.) in patches became the major component of the sward. Greater variation in G 2 than in G 4 indicated that growth responded quickly to current environmental conditions. A nonlinear regression accounted for 74% of the variance in G 2 when related to the 3 climatic factors of daylength, soil temperature at 10 cm depth and the soil moisture to a depth of 10 cm, and a plant factor of green herbage yield. The 26 % of unaccounted variance appears to be associated with an effect of stocking rate, possibly botanical composition. The botanical composition was not continuously monitored hence the only sward character included in the investigation was herbage yield. Comparison of the patterns of pasture growth from different latitudes indicated that while the growth pattern in south-western Victoria is erratic, it is intermediary between Mediterranean and temperate pasture types. Understanding this aspect has implications for improving the efficiency of animal production in this environment.


1967 ◽  
Vol 69 (1) ◽  
pp. 47-69 ◽  
Author(s):  
C. R. W. Spedding ◽  
J. E. Betts ◽  
R. V. Large ◽  
I. A. N. Wilson ◽  
P. D. Penning

During the last ten years or so, the management of sheep for intensive lamb production has been studied on a considerable scale, and a variety of grazing systems have been investigated (Dickson, 1959; Cooper, 1959; Spedding & Large, 1959; Boaz, 1959). It is still too soon to specify precisely the place that any of these systems should occupy in sheep-production processes, in relation to breed, lambing percentage, weight of lamb at slaughter, stocking rate, botanical composition of the pasture, size of ewe and level of her milk yield. Quite apart from these biological considerations, the full economic implications are by no means clear. What has emerged most clearly, however, is that much higher stocking rates can be tolerated than had generally been regarded as safe and that, at these stocking rates, productivity can be extremely high.


1978 ◽  
Vol 18 (95) ◽  
pp. 788 ◽  
Author(s):  
NH Shaw

Changes in the yield, botanical composition and chemical composition of a native pasture (Heteropogon contortus dominant) oversown with S. humilis (T.S.) were measured in a grazing experiment from 1966 to 1973. The 24 treatments were factorial combinations of two sowing methods for T.S. (ground sowing into spaced cultivated strips, or aerial sowing), three levels of molybdenized superphosphate (F0 = nil ; F1 = 125 kg ha-1 annually; F2 = 250 kg ha-1 annually plus an extra 250 kg ha-1 initially) and four stocking rates. Stocking rates were gradually increased during the experiment and for the last three years overlapping ranges were used for the three fertilizer levels; the overall range was then from 0.55 to 1.65 beasts ha 1 T.S. establishment by ground sowing was much more reliable than from aerial sowing, giving twice the average percentage frequency, and this proportion was maintained over years. High fertilizer improved establishment and the best legume stands were in the high fertilizer high stocking rate treatments. Total presentation yield of pasture was increased by fertilizer and reduced by high stocking rates. Over the last two years the means for March, adjusted by regression to the overall average stocking rate of 0.98 beasts ha-1, were 31 20,4020 and 5370 kg ha-1 for F0, F1 and F2 respectively, but these yields were reduced by ca 25 per cent for an increase of 0.5 beasts ha-1. H. contortus remained dominant and its mean contribution to total yield increased from 48 per cent in 1969 to 67 per cent in 1973. This proportion was reduced by 12.8 per cent over the range from 0.55 to 1.65 beasts ha-1, but high fertilizer had the opposite effect so that differences between the extremes low stocked F0 and high stocked F2 were small. The DM percentage yield of T.S. was strongly increased by fertilizer, and, most importantly, also by high stocking rates in the presence of fertilizer. Values for F0 treatments remained below 10 per cent, but in the final year values for F1 and F2 at the highest stocking rates were 36 and 27 per cent, respectively. Despite these large changes in T.S., there was overall stability of botanical composition. Phosphorus and nitrogen concentrations in T.S. and H. contortus were increased by superphosphate but there was an overall decline in potassium concentration. Soil phosphorus levels were greatly increased


2010 ◽  
Vol 50 (2) ◽  
pp. 138 ◽  
Author(s):  
B. A. McGregor

The effects of animal species (AS; Angora goats, Merino sheep or goats and sheep mixed grazed together at ratio 1 : 1) and stocking rate (SR; 7.5, 10 and 12.5 animals/ha) on the availability, botanical composition and sward characteristics of annual temperate pastures under continuous grazing were determined in a replicated experiment from 1981 to 1984. AS and SR had significant effects on pasture availability and composition and many AS × SR interactions were detected. The pastures grazed by sheep had significantly reduced content and proportion of subterranean clover and more undesirable grasses compared with those grazed by goats. There were no differences in dry matter availabilities between goat- and sheep-grazed pastures at 7.5/ha, but at 10 and 12.5/ha goat pastures had significantly increased availabilities of green grass, dead and green clover and less weeds compared with sheep pastures. There was a significant AS × SR interaction for the density of seedlings in May following pasture germination. Between July and January, the height of pastures was greater under goats than sheep but from January to March pasture height declined more on goat-grazed than on sheep-grazed pastures. There was an AS × SR interaction for incidence of bare ground. Increasing the SR increased bare ground in pastures grazed by sheep but no change occurred on pastures grazed by goats. Changes in pasture characteristics due to increased SR were minimised on pastures grazed by goats but the grazing of sheep caused larger and faster changes and the pastures were damaged at the highest SR. Goats did not always select the same herbage material as sheep, changed their selection between seasons and were not less selective than sheep. Angora goats were flexible grazers and continually adapted their grazing behaviour to changing herbage conditions. Goat grazing led to an increase in subterranean clover, an accumulation of dead herbage at the base of the sward, reduced bare ground, taller pastures in spring and a more stable botanical composition. Mixed-grazed pasture characteristics were altered with SR. With careful management Angora goats on sheep farms may be used to manipulate pasture composition, to speed up establishment of subterranean clover, to decrease soil erosion and to reduce weed invasion.


1976 ◽  
Vol 27 (6) ◽  
pp. 881 ◽  
Author(s):  
JG Mulholland ◽  
JB Coombe ◽  
M Freer ◽  
WR McManus

The production of young crossbred wethers grazing oat, barley and wheat stubbles was measured in each of three years at stocking rates ranging from 15 to 30/ha. In one year, production on 'weedy' stubbles was compared with that of 'clean' (weed-free) stubbles, and also the effect of a wheat–urea–mineral supplement on the production of sheep was measured on oat stubble. Liveweight change and wool production were significantly influenced by the availability of green plant material and by stocking rate, but not by supplementation. The maximum liveweight loss in any year was 7.5 kg and the maximum gain 6.0 kg, both recorded over 11 weeks' grazing. Mean daily clean wool production was 9.9 g/sheep at the lower stocking rate and 6.6 g/sheep at the higher rate, but production per hectare was 10–60% higher at the heavier stocking rate. The ranking of the crop stubbles with respect to animal production was not consistent from year to year. Intense selection for green plant material by sheep resulted in the proportion of green in the diet being nearly always greater than 80%, when the weight of this material on the plots was more than 40 kg dry matter/ha. It appeared that a low intake of nitrogen was not the main limitation to animal production. A maximum of only 36% of the crop residue which disappeared during the experiment could be accounted for as animal intake. Thus it is unlikely that the potential of cereal residues as a source of food for animal production will be realized with grazing sheep.


1982 ◽  
Vol 22 (116) ◽  
pp. 182 ◽  
Author(s):  
WK Anderson ◽  
RJ Parkin ◽  
MD Dovey

The effects of weather on clover scorch disease caused by Kabatiella caulivora, the effects of the disease on pasture and sheep production, and the effect of sheep stocking rate (6, 8, 10 and 12 sheep/ha) on the disease were studied in a field experiment over three seasons near Albany, Western Australia. Spraying with benlate was used to control clover scorch on some treatments. Mean temperatures during the period when symptoms of the disease increased were in the range 11-17�C. Rainfall was frequent each year during the same period. The rapid increase in disease symptoms was observed when pasture dry matter on offer was approximately 2500 kg/ha. Disease symptoms decreased during a period of water stress of the pasture. Clover scorch disease had no consistent effect on pasture or animal production except that pasture dry matter on offer in spring was reduced in the unsprayed treatments at the lower stocking rates in the second two years. Higher stocking rates (10 and 12 sheep/ha) reduced the level of clover scorch symptoms without the use of chemical control with benlate. At the period of peak scorch symptoms a stocking rate of 10 sheep/ha reduced disease incidence by 20-35% compared with 6 sheep/ha in unsprayed plots. Increased sheep stocking rates are suggested as a possible alternative to chemical control or replacement of susceptible strains of subterranean clover in grazed pasture.


1973 ◽  
Vol 81 (2) ◽  
pp. 211-218 ◽  
Author(s):  
J. P. Langlands ◽  
I. L. Bennett

SummaryWool production and wool characteristics are reported for a 5-year period in which sheep grazed Phalaris tuberosa–Trifolium repens pastures at stocking rates ranging from 2·5 to 37·1 sheep/ha. The utilization of nutrients for maintenance and wool production were calculated over shorter periods.Maximum wool production/ha was always recorded at the highest stocking rate attained. The highest annual maximum was 111 kg clean wool/ha in 1963–4. The decline in wool production/sheep/unit increase in stocking rate was greatest during winter and the amplitude of the seasonal rhythm in wool production increased with stocking rate.At high stocking rates wool count increased, staple length and character declined, colour and handle improved, soundness tended to decline and fibre entanglement (cotting) to increase particularly during drought. Live-weight gain/sheep also declined with stocking rate, the rate of decline being greatest during drought. Maximum live-weight change/ha was attained at a lower stocking rate than maximum wool production/ha.The maintenance requirement of grazing sheep was estimated to be 58·3 kcal metabolizable energy/day/kg live weight and did not vary consistently with stocking rate. The value was 79% greater than the requirements for penned sheep estimated from fasting heat production.Efficiency of wool production was defined as wool grown/100 g digestible organic matter intake (ED) and as wool grown/100 g nitrogen intake (EN). EN declined linearly with increasing stocking rate but the intercepts differed between months, and were least in late winter and early spring. En declined with stocking rate in winter and increased during summer. At low stocking rates, ED showed some variation throughout the year but this was much greater at high stocking rates.


1968 ◽  
Vol 8 (30) ◽  
pp. 33 ◽  
Author(s):  
KD McLachlan

The response by Phalaris-subterranean clover pasture to applied nitrogen, phosphorus, and sulphur was measured at two sites on the same soil. Both sites had the same fertilizer history. For the past fifteen years the stocking rate on one site had been maintained at not less than three times that of the other. Yield responses to phosphorus were obtained at both sites. The response at the lower stocking rate was greater than that at the high stocking rate. A similar response pattern was found for nitrogen, but the difference in response between the stocking rate treatments was not significant. The pastures did not respond to sulphur. The trend was for sulphur to depress the yield at both stocking rates. The evidence suggests that less superphosphate was needed to maintain pasture production at high stocking rates than at low ones. Available phosphorus, determined chemically, increased with grazing intensity. There was no evidence that a particular soil phosphorus fraction was associated with this increase, or the lower requirement for added fertilizer. The only significant difference between grazing treatments were increases in the iron, calcium, and organic forms at the higher grazing intensity. It is probable that the present pasture response, and hence the fertilizer requirement of the soil, was influenced more by the altered growth potential of the plants under grazing, than by the effect of grazing on the soil nutrient status.


1987 ◽  
Vol 27 (3) ◽  
pp. 349 ◽  
Author(s):  
CW Thorn ◽  
MW Perry

Pasture production, pasture composition and quality, and liveweight, body condition and wool growth of Merino weaner wethers were monitored over 2 seasons and at 2 stocking rates (4 and 8 sheep/ha) on a mixed annual grass-legume pasture sprayed with propyzamide to control grasses. Propyzamide virtually eliminated annual grasses from the pasture (less than 5 kg/ha of grass dry matter in spring v. 403 kg/ha on untreated pasture in 1981) and this carried over into the second season (61 kg/ha v. 647 kg/ha in spring 1982). Propyzamide treated pastures had less total dry matter (P = 0.05) throughout 1981: however, except for a single sample date, there was no effect of propyzamide on total available pasture in the second season. Increased growth of clover and capeweed compensated for the absence of the grasses. The higher stocking rate reduced available clover, capeweed and total dry matter (P = 0.05) throughout both years. Sheep grazing grass-free pastures had lower liveweights during winter in both years, but made compensatory gains during late spring and summer consistent with the higher quality (1.6 v. 1.07% nitrogen when sampled in January) of propyzamide treated pastures. In 198 1, wool growth rates were reduced at the higher stocking rate and total clean wool production was reduced from 4.55 kg/sheep at 4/ha to 3.65 kg/sheep at 8/ha. Pasture treatment had no effect on wool production in either year. The implications of using selective herbicides to remove the annual grass component of legume-based annual pastures in south-western Australia are dis cussed in relation to pasture and sheep production.


1976 ◽  
Vol 16 (79) ◽  
pp. 181 ◽  
Author(s):  
TH Brown

The effect of deferred autumn grazing and stocking rate on an annual pasture was monitored for five years at Kybybolite Research Centre in the south-east of South Australia. Pasture availability, yearly production and botanical composition were measured under a series of eight stocking rates from 12.4 to 29.7 Merino wethers per hectare. Autumn deferment resulted in extra available pasture during the winter months of June, July and August. However, the continously grazed pastures reached the same level of availability as the deferred pastures in spring. By the third year of the experiment yearly pasture production irrespective of grazing management was greatly reduced at the higher stocking rates. This reduction was associated with an invasion of Poa annua and Juncus bufonius. Autumn deferment tended to favour the growth of Wimmera ryegrass at the lower stocking rates whereas continuous grazing tended to favour clover growth at these stocking rates.


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