Effect of deferred autumn grazing and stocking rate of sheep on pasture production in a Mediterranean-type climate

1976 ◽  
Vol 16 (79) ◽  
pp. 181 ◽  
Author(s):  
TH Brown
Keyword(s):  
South Australia ◽  
Grazing Management ◽  
Research Centre ◽  
Botanical Composition ◽  
Stocking Rate ◽  
Pasture Production ◽  
Continuous Grazing ◽  
Wimmera Ryegrass ◽  
June July ◽  
Stocking Rates

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.

A comparison of continuous grazing and deferred autumn grazing of Merino ewes and lambs at 13 stocking rates

1977 ◽  
Vol 28 (5) ◽  
pp. 947 ◽  
Author(s):  
TH Brown
Keyword(s):  
Growth Rates ◽  
South Australia ◽  
Grazing Management ◽  
Research Centre ◽  
Late Winter ◽  
Stocking Rate ◽  
Pasture Production ◽  
Grazed Pastures ◽  
Stocking Rates ◽  
Lamb Growth

The performance of Merino ewes and their lambs was measured when the sheep were either continuously grazed or autumn-deferred on annual pastures. The two management systems were compared at a series of 13 stocking rates from 4.9 to 19.8 ewes ha-1 for 5 years from 1970 to 1974 at the Kybybolite Research Centre, South Australia. The deferred sheep were fed in yards on a mixture of oat grain and hay at 6.8 kg per head per week during the 6-week deferment period. It was found that the continuously grazed ewes required very little hand-feeding up to a stocking rate of 17.3 ewes ha-1. Grazing management had little or no effect on wool production in ewes or lambs, on the number of lambs born and weaned, or on lamb growth rates. Although the incidence of pregnancy toxaemia was very low (1%) it was higher in the deferred treatments. Autumn deferment resulted in extra pasture during the winter months of June and July. However, the continuously grazed pastures reached the same level of availability as the deferred pastures in late winter and early spring. Total yearly pasture production tended to be greater on the continuously grazed pastures and increased as the stocking rate increased. It is concluded that there is little merit in adopting an autumn deferment system of grazing management for Merino ewes and lambs. A relationship between lamb growth rate and both available pasture and pasture height is presented. It would appear that pasture height measurements are no better predictors of Iamb growth rates than pasture yield measurements.

Effects of grazing management and stocking rate on pasture production, ewe liveweight, ewe fertility and lamb growth on subterranean clover-based pasture in Western Australia

2001 ◽  
Vol 41 (2) ◽  
pp. 161 ◽  
Author(s):  
H. Lloyd Davies ◽  
I. N. Southey
Keyword(s):  
Growth Rate ◽  
Western Australia ◽  
Subterranean Clover ◽  
Grazing Management ◽  
Stocking Rate ◽  
Pasture Production ◽  
Continuous Grazing ◽  
Grazing System ◽  
Stocking Rates ◽  
Lamb Growth

Border Leicester x Merino ewes joined to Dorset Horn rams were grazed for 3 years on subterranean clover-based pastures established on virgin ground at Bakers Hill, Western Australia, at 3 stocking rates and 2 systems of grazing management (viz. continuous grazing compared with a deferred grazing system which was designed to ensure that pasture availability met the nutritional requirements of breeding ewes at critical phases of their reproductive cycle). Both stocking rate and grazing management affected pasture availability: there was always a greater amount of pasture available on offer under the deferred grazing system. However, this extra pasture rarely increased animal production; the effect of the deferred grazing compared with continuous grazing was inconsequential for ewe liveweight in late pregnancy and for lamb growth rate. The deferred grazing system promoted grass dominance at all stocking rates whereas there was only 24% grass under continuous grazing at the high stocking rate. Stocking rate on some occasions affected ewe liveweight at joining but always affected the prelambing weight. The highest stocking rate on some occasions reduced twinning rate. Stocking rate (particularly in 1966) affected lamb growth rate. The combination of the effect of stocking rate on twinning rate, lamb survival and lamb growth rate resulted in a lower proportion of lambs achieving 30 kg liveweight per lamb marked at higher stocking rates (3-year mean low stocking rate 106% lambs marketed; medium stocking rate 95% and high stocking rate 80%). In 1966, total plasma ketones were lower and plasma glucose (measure of ewe metabolic status) was higher on the deferred system than on the continuously grazed system.

The inter-relationships of grazing method and stocking rate in the efficiency of pasture utilization by dairy cattle

1963 ◽  
Vol 61 (2) ◽  
pp. 147-166 ◽  
Author(s):  
C. P. McMeekan ◽  
M. J. Walshe
Keyword(s):  
Dairy Cows ◽  
Large Scale ◽  
Age Distribution ◽  
Grazing Management ◽  
Vanishing Point ◽  
Stocking Rate ◽  
Rotational Grazing ◽  
Continuous Grazing ◽  
Grazing System ◽  
Stocking Rates

1. A large-scale grazing management study comparing rotational grazing and continuous grazing with dairy cows at two stocking rates over four complete production seasons is described.2. The four treatments were: (i) controlled grazing, light stocking rate; (ii) controlled grazing, heavy stocking rate; (iii) uncontrolled grazing, light stocking rate; (iv) uncontrolled grazing, heavy stocking rate.Each treatment involved 40 cows for a first 2-year phase and 42 cows for the following 2 years. Each herd had a normal age distribution pattern and seven 2-year-old first lactation heifers (17% of total herd) were introduced each year to maintain this pattern.3. Stocking rate was the more important factor affecting the efficiency of pasture utilization as measured by per acre output of milk and butterfat. In general, high stocking was associated with higher outputs per acre despite lower yields per animal.4. Grazing method was of less importance. In general, controlled rotational grazing was superior to uncontrolled continuous grazing, both per animal and per acre, but the average influence even of these extremes of management was only half that of stocking rate.5. Significant interactions between stocking rate and grazing method existed. Under continuous grazing a point was reached where production per acre declined to the vanishing point with increased stocking rate due to excessive depression of per cow yield: this point was not reached under rotational grazing at the same high stocking levels.6. The results suggest that optimum stocking rate under rotational grazing occurs at a level some 5–10% higher than under continuous grazing. A depression of 10–12% in per cow yield, compared with more lenient grazing, corresponds with optimum stocking level irrespective of the grazing system. This estimate is suggested as a guide line in applying the principles involved.

Superphosphate and stocking rate effects on a native pasture oversown with Stylosanthes humilis in central coastal Queensland. 1. Pasture production

1978 ◽  
Vol 18 (95) ◽  
pp. 788 ◽  
Author(s):  
NH Shaw
Keyword(s):  
Soil Phosphorus ◽  
Total Yield ◽  
Botanical Composition ◽  
Stocking Rate ◽  
Pasture Production ◽  
Average Percentage ◽  
Heteropogon Contortus ◽  
Native Pasture ◽  
Nitrogen Concentrations ◽  
Stocking Rates

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

Levels of total nitrogen and total volatile fatty acids in the rumen fluid of sheep under different grazing management systems

1967 ◽  
Vol 7 (28) ◽  
pp. 434
Author(s):  
WR McManus
Keyword(s):  
Fatty Acids ◽  
Total Nitrogen ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Subterranean Clover ◽  
Grazing Management ◽  
Stocking Rate ◽  
Continuous Grazing ◽  
Grazing System ◽  
Stocking Rates

Concentrations of total nitrogen and total volatile fatty acids in the rumen fluid of sheep grazing improved pastures were measured for ten months in a dry year on the southern tablelands of New South Wales, and the concentrations of nitrogen and volatile fatty acids (V.F.A.) were related to season, wool production, and grazing management. The observations were made during two long-term grazing management experiments. In the first experiment four groups of breeding Merino ewes grazed a Wimmera ryegrass-subterranean clover (Lolium rigidum Gaud.-Trifolium subterraneum L.) pasture. A deferred grazing system (autumn saving) of pasture management was compared with continuous grazing at stocking rate treatments equivalent to 7.0 and 3.5 ewes to the acre. In the second experiment two groups of Merino weaners grazed a Phalaris tuberosa-subterranean clover pasture at a stocking rate equivalent to 8.6 sheep to the acre. One group received a hay supplement, the other did not. In both experiments nitrogen values were low between late autumn and mid-winter and again between late spring and summer, and high in early autumn and again in spring (P<0.05). The low levels were about 55 per cent of peak autumn and spring levels in (experiment 1) and 60 per cent of peak autumn and spring levels in (experiment 2). Total V.F.A. did not vary significantly between seasons in either experiment. At the higher stocking rate the ewes had lower levels of rumen total nitrogen than at the lower stocking rate. V.F.A. did not vary consistently between stocking rates. At both stocking rates ewes on the autumn saving system of grazing management had more nitrogen in the rumen fluid during late pregnancy and early lactation than did those on the continuous grazing system (P<0.001). After the ewes had access to the saved pasture, autumn saving resulted in a higher concentration of volatile fatty acids than continuous grazing (P< 0.05). Although feeding a hay supplement benefited the weaners the concentrations of total nitrogen in the rumen fluid of the two groups of sheep were similar. There was a fairly consistent tendency for the group receiving hay to have lower concentrations of volatile fatty acids in their rumen fluid. Possible reasons for these effects are discussed.

scholarly journals Key pasture and milksolids production indicators from two Waikato farmlets differing in inputs, stocking rate, pasture allowance and nitrate leaching

2016 ◽  
Vol 78 ◽  
pp. 45-50 ◽  
Author(s):  
C.G. Roach ◽  
C.B. Glassey ◽  
K.A. Macdonald
Keyword(s):  
Nitrate Leaching ◽  
Grazing Management ◽  
Late Winter ◽  
Botanical Composition ◽  
Stocking Rate ◽  
Nitrogen Fertiliser ◽  
Lactating Cows ◽  
Pasture Quality ◽  
Winter Grazing ◽  
Stocking Rates

Two DairyNZ farmlets, differing in nitrogen fertiliser inputs, cow genetic merit and autumn/winter grazing management, with stocking rates of 2.6 ('Future') and 3.2 ('Current') cows/ha, were compared for pasture residual and quality over 4 years. Target intakes for lactating cows were 18 and 16 kg DM/cow/day, respectively, with target grazing residuals of 3.5-4 cm (1500 kg DM/ha in late winter/spring, 7-8 clicks on the rising plate meter) for both herds. Measurement of grazing residuals, pasture quality and botanical composition identified small differences between farmlets. Grazing residuals on the Future farmlet averaged 0.2 cm (0.4 clicks on rising plate meter, RPM) (P

Effect of anthelmintic dosing and stocking rate on the productivity of weaner sheep in a Mediterranean climate environment

1985 ◽  
Vol 36 (6) ◽  
pp. 845 ◽  
Author(s):  
TH Brown ◽  
GE Ford ◽  
DW Miller ◽  
I Beveridge
Keyword(s):  
Significant Variation ◽  
Death Rate ◽  
Mediterranean Climate ◽  
South Australia ◽  
Research Centre ◽  
Stocking Rate ◽  
The Third ◽  
Resultant Effect ◽  
The Mean ◽  
Stocking Rates

The effects of nematodiasis on productivity in weaner sheep was measured at Kybybolite Research Centre, South Australia, during 1976-81. Three levels of control were compared at two stocking rates (7.5 ha-1 and 16 ha-1). One group was not treated with anthelmintics, another group was treated every 3 weeks and the third group (Planned) was given five doses of anthelmintics each year: once in October, twice during the hot dry summer and twice during the winter months. The sheep were replaced by weaner sheep at shearing in October each year. The drenching regime of sheep on a particular paddock was the same for all five years. Nematodes, particularly Trichostrongylus spp., had a very large effect on the production of the sheep. The mean annual death rate of the untreated sheep was 22% and 56070, for the low and high stocking rates respectively. The regularly drenched sheep were 9-31% heavier and cut 11-46% more wool than the survivors of the untreated sheep at the low stocking rate. At the high stocking rate the regularly drenched sheep were 17-58% heavier and cut 14-56% more wool than the survivors of the undrenched sheep. The sheep given the Planned drenching program had similar final liveweights each year to the regularly drenched sheep, and in only two years out of five did the regularly drenched sheep produce significantly more wool than the sheep given the Planned program. The effect of drenching on the contamination of wool with faeces, and the resultant effect on the incidence of fly strike, is discussed. There was a significant variation between years in amount of available pasture, and there was generally slightly more pasture available on the Nil drench treatment paddocks.

The effects of sheep treading and grazing on pasture and soil characteristics of irrigated annual pastures

1979 ◽  
Vol 30 (4) ◽  
pp. 741 ◽  
Author(s):  
PA Witschi ◽  
DL Michalk
Keyword(s):  
Bulk Density ◽  
Subterranean Clover ◽  
Soil Characteristics ◽  
Combined Effect ◽  
Late Winter ◽  
Botanical Composition ◽  
Stocking Rate ◽  
Grazing Experiment ◽  
Wimmera Ryegrass ◽  
Stocking Rates

The two experiments reported examined the effects of sheep treading on pasture growth and soil characteristics on autumn-irrigated subterranean clover-Wimmera ryegrass pastures and their subsequent influence on winter production. Treading only (experiment 1) increased the bulk density of soil by 40% as the stocking rate increased from 0 to 39.2 sheep ha-1. This caused a 33% reduction in late winter production (July), the decline (675 kg ha-1) being due mainly to a reduction in the proportion of ryegrass in the pasture. The combined impacts of treading and grazing (experiment 2) proved more detrimental to subsequent pasture recovery. At the July measurement, treading reduced production by 20% when the stocking rate was increased from 0 to 19.6 sheep ha-1, while the combined effect produced a 58% loss in yield. In addition to stocking rate, the length of the pre-grazing establishment period proved critical, with greater compaction evident in plots stocked 24 h after irrigation. This compaction affected the botanical composition, significantly more ryegrass being present in compacted plots, although increased tillering was encouraged by intense defoliation at high stocking rates which intensified this effect.

Pasture production of two cultivars of Trifolium subterraneum at Kybybolite, South Australia

1992 ◽  
Vol 32 (5) ◽  
pp. 611 ◽  
Author(s):  
AD Craig
Keyword(s):  
South Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Biochanin A ◽  
Stocking Rate ◽  
Seedling Density ◽  
Pasture Production ◽  
Seed Reserves ◽  
Seed Yields ◽  
Stocking Rates

Two cultivars of subterranean clover, Trikkala and Mt Barker, were continuously grazed by Merino ewes and lambs at 3 stocking rates (8, 13, and 18 ewes/ha) from 1976 to 198 1. The pastures were assessed for clover seedling density, pasture availability and composition, seed reserves, and oestrogen content. Trikkala produced consistently higher seed yields than Mt Barker, with an average yield 3.36 times that of Mt Barker by January 1981 (1178 v. 350 kg/ka). The higher Trikkala seed yields resulted in improved clover seedling densities and increased amounts of clover in the pastures. At the last assessment (8 September 1980) there was an average of 3.15 times more clover in the Trikkala pastures than in the Mt Barker pastures (469 v. 149 kg/ha). Trikkala produced more total available pasture than Mt Barker, at several samplings, because the contribution of subterranean clover to total available pasture was greater after September 1978. The formononetin, genistein and biochanin A content of both cultivars decreased with increasing stocking rate. The most consistent effects were observed in genistein content, with reductions occurring in 7 of the 11 samplings.

OBSERVATIONS ON THE RELATIONSHIP BETWEEN SOIL FERTILITY, PASTURE BOTANICAL COMPOSITION, AND PASTURE GROWTH RATE; FOR A NORTH ISLAND LOWLAND PASTURE

1988 ◽  
pp. 141-144
Author(s):  
C. Matthew ◽  
R.W. Tillman ◽  
M.J. Hedley ◽  
M.C. Thompson
Keyword(s):  
Soil Fertility ◽  
Botanical Composition ◽  
Stocking Rate ◽  
Pasture Production ◽  
Mean Values ◽  
Olsen P ◽  
Sheep Farm ◽  
Tiller Density ◽  
Stocking Rates ◽  
The Relationship

Soil chemical fertility, pasture composition and pasture production data were collected for seven 'microsites' within two farmlets at Massey University's No. 1 sheep farm. Palmerston North. The two farmlets had been maintained for twenty years at stocking rates of 26 and 16 su/ha, and were found to have gradients (presumed to result from sheep grazing and camping behaviour) of increasing soil fertility away from a road and towards a shelterbelt. Microsites were placed along these gradients to include contrasting fertility levels for the two stocking rates. Mean values for soil pH, Olsen P and 'quicktest' K tiller density for the various pasture species and pasture production at each of the seven microsites are presented. A microsite where Olsen P = 109 was barley grass dominant and produced 10.5 t DM/ha/year. For other microsites ryegrass tillers per m2 increased with P and stocking rate; and white clover and sweet vernal growing points/tillers per m2 decreased with increasing P. Production ranged from 9.9 t DM/ha/year where Olsen P = 14 to 19.1 t DM/ha/year with different seasonal timing where Olsen P = 66.

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