Studies in pasture management for the breeding ewe. I. Effects on ewe liveweights, incidence of pregnancy toxaemia, lamb birth weights, and neo-natal mortality

1968 ◽  
Vol 19 (4) ◽  
pp. 605
Author(s):  
HL Davies
Keyword(s):  
Birth Weight ◽  
Early Pregnancy ◽  
Subterranean Clover ◽  
Late Pregnancy ◽  
Stocking Rate ◽  
Pasture Management ◽  
Continuous Grazing ◽  
Natal Mortality ◽  
Stocking Rates ◽  
Pregnancy Toxaemia

Breeding ewes were run under three systems of pasture management on sown pastures (based on subterranean clover) at Canberra. The ewes lambed from mid August to late September. The three management treatments were: (i) Continuous grazing (treatment CG). (ii) Ewes were confined to one-third of the whole area available in early pregnancy, so that feed was autumn-deferred for late pregnancy (treatment DP).(iii) Ewes were confined to a portion (one-third in 1956, one-half in 1957) of the area for the whole of pregnancy in order to ensure an adequate amount of feed for lactation (treatment DL). Two stocking rates and two breeds of ram were compared (Merino and Border Leicester). Treatment DL resulted in unsatisfactory liveweight gains during pregnancy, a far higher incidence of pregnancy toxaemia, reduced lamb birth weight, and increased neo-natal mortality. At the low stocking rate there were no significant differences between treatments CG and DP. At the high stocking rate, treatment DP reduced liveweight gain in early pregnancy and ensured an adequate liveweight gain in late pregnancy. The incidence of pregnancy toxaemia was lower at the high stocking rate in 1957 on treatment DP compared with CG. At the higher stocking rate, ditocous ewes on treatment DP gained more weight in late pregnancy than those on CG or DL.

The productivity of breeding ewes grazing on lucerne or grass and clover pastures on the tablelands of southern Australia. II. Wool production and ewe weight.

1983 ◽  
Vol 34 (5) ◽  
pp. 537 ◽  
Author(s):  
JR Donnelly ◽  
FHW Morley ◽  
GT McKinney
Keyword(s):  
Subterranean Clover ◽  
Late Pregnancy ◽  
Chemical Characteristics ◽  
Wool Production ◽  
Weight Losses ◽  
The Difference ◽  
Supplementary Feed ◽  
Physical And Chemical ◽  
Stocking Rates ◽  
Pregnancy Toxaemia

Spring-lambing Merino and crossbred ewes grazing on dryland lucerne pastures were generally heavier throughout the year than ewes grazing on phalaris and subterranean clover pastures, even though they experienced greater weight losses during winter. These losses were mostly eliminated by compensatory gains in spring. Annual fleece weights of the Merino ewes grazing on lucerne or phalaris and subterranean clover pastures declined linearly by 146 and 64 g respectively for each additional ewe carried over a range of stocking rates from 9 to 18 ha-1. Corresponding figures for crossbred ewes were 114 and 46 g. In each case the difference between pasture species was significant (P < 0.02). Only at the lowest stocking rates were fleeces from ewes on lucerne heavier (by c. 500 g) than those from ewes on phalaris. At the highest stocking rates, there were no advantages in terms of wool production from grazing breeding ewes on lucerne. Not only was there a greater need for supplementary feed during late pregnancy to avoid losses from pregnancy toxaemia, but the lucerne pastures at all stocking rates proved more sensitive to unfavourable physical and chemical characteristics of soils than did phalaris and subterranean clover pastures. The fleece weights of Merino and crossbred ewes declined, on average, by 70 and 50 g per year for ewes aged between 1+ and 6+ years. Pregnancy reduced fleece weights by 5-10% in Merinos and 5-21% in crossbred ewes, depending on seasonal conditions which varied from year to year. For Merinos only, dry ewes grew about 4% more wool than lactating ewes. No other effects of reproduction on fleece weights were observed.

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.

Some variables influencing production of prime lamb and wool from pasture

1971 ◽  
Vol 11 (52) ◽  
pp. 498
Author(s):  
GW Arnold ◽  
A Axelsen ◽  
HR Gharaybeh ◽  
HW Chapman
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Late Pregnancy ◽  
Reproductive Rate ◽  
Bromus Inermis ◽  
Early Winter ◽  
Stocking Rate ◽  
Wool Production ◽  
Brome Grass ◽  
Stocking Rates

In an experiment at Canberra, A.C.T., extending over four years, crossbred and Merino ewes were grazed at three stocking rates on pastures of either phalaris (Phalaris tuberosa), phalaris combined with separate paddocks of brome grass (Bromus inermis), and cocksfoot (Dactyllis glomerata), or separate paddocks of brome grass and cocksfoot. Subterranean clover (Trifolium subterraneum) was present in all pastures. One-, two-, and three-paddock systems and two times of lambing were also compared. Pasture availability and animal productivity were measured. Early lambing resulted in more prime lambs although the later lambs had slightly higher rates of gain. At the highest crossbred stocking rate studied (seven ewes per acre) wool production per acre was still increasing, but number of prime lambs and lamb liveweight gain did not increase above stocking rates of five ewes per acre. More feed was available to ewes during late pregnancy on treatments allowing feed rationing in autumn and early winter, but neither rationing nor including brome grass and cocksfoot in the system increased animal productivity beyond that achieved by grazing phalaris continuously. At stocking rates up to six ewes per acre, animal production was greatest from phalaris grazed continuously. Stocking rates were designed to provide similar weights of either Merino or crossbred ewes per acre at each stocking level. Because more lambs were born to crossbred ewes they had less feed than Merinos in spring and summer at all stocking rates. Lambs from crossbred ewes were heavier at birth and grew faster than lambs from Merino ewes. More prime crossbred lambs were produced per acre at all stocking levels. The reproductive rate and lamb production of Merino ewes dropped sharply with increased stocking rate. Fleeceweights were similar for both breeds, particularly at low stocking rates. Wool production per acre increased with stocking rate and was higher from Merinos at each level.

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.

Beef production from native pastures sown to fine-stem stylo in the Burnett region of south-eastern Queensland

1979 ◽  
Vol 19 (97) ◽  
pp. 140 ◽  
Author(s):  
EJ Bowen ◽  
KG Rickert
Keyword(s):  
Stocking Rate ◽  
Management Options ◽  
North West ◽  
Heteropogon Contortus ◽  
South Eastern ◽  
Continuous Grazing ◽  
Weight Gains ◽  
The Mean ◽  
Native Pastures ◽  
Stocking Rates

At Gayndah, south-eastern Queensland, a native Heteropogon contortus pasture, sown to fine-stem stylo (Stylosanthes guianensis var. intermedia), and invaded by red natal grass (Rhynchelytrum repens), was grazed by weaner steers from June 1 in three treatments : heavy and light put-and-take grazing for five years from 1971, and set-stocked at 1.37 animals ha-1 for two years from 1974. Weight gains in the put-and-take treatments were not significantly different. The mean annual liveweight gain was 167 kg animal-1 at a mean equivalent stocking rate of 1.47 animals ha-1. Over the same period unsown native pasture, cleared of timber, gave a gain of 62 kg animal-1 at 0.62 animals ha-1. In all seasons except summer, weight gains declined linearly with stocking rate and in 1972-73, with a mean equivalent stocking rate of 2.66 animals ha-1, the annual gain was almost halved. When equivalent stocking rates were 0.9, 0.9, 1.8 and 1.2 animals ha-1 in winter, spring, summer and autumn, the respective gains were 4, 73, 65 and 45 kg animal-1. The set-stocked treatment had a mean annual gain of 147 kg animal-1. At another site 116 km north-west of Gayndah, two paddocks of Heteropogon contortus and fine-stem stylo were set-stocked with weaners over four years. One paddock had four applications of superphosphate of 250 kg ha-1. The mean annual liveweight gains were significantly different, being 154 and 143 kg animal-1 in the fertilized and unfertilized paddocks at mean stocking rates of 0.83 and 0.74 animals ha-1, respectively. In a grazing protection experiment the density of fine-stem stylo declined exponentially with an accumulation of pasture dry matter in spring and summer. Heavy continuous grazing, an annual hay cut and an accidental fire all increased the density of fine-stem stylo. Management options to maintain the density of fine-stem stylo and the relative importance of the legume and grass to animal production are discussed.

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.

Effect of time of joining and rate of stocking on the production of Corriedale ewes in southern Victoria. 3. Wool growth and the composition and availability of pasture

1975 ◽  
Vol 15 (73) ◽  
pp. 159 ◽  
Author(s):  
PA Kenney ◽  
IF Davis
Keyword(s):  
Fibre Diameter ◽  
Late Pregnancy ◽  
The Other ◽  
Early Lactation ◽  
Stocking Rate ◽  
Wool Production ◽  
Wool Growth ◽  
The Mean ◽  
Brome Grass ◽  
Stocking Rates

A study was made during a three year period (1 968-1 970) of wool production by a flock of 540 ewes grazing annual pasture at Werribee, Victoria. The ewes were stocked at three rates (5, 7 1/2 and 10 ewes ha-1) and lambed between July 6 and August 20 or between September 10 and October 29 each year. Fibre diameter and length of wool samples were measured in 1968, 1969 and 1970 ; in 1970 growth of greasy wool was calculated from staples of dye-banded wool. Wool growth was reduced in all ewes during late pregnancy and early lactation but was not affected during late lactation in ewes lambing in September. The proportion of tender fleeces from all ewes was greater in 1970 and the weight of fleeces from only those ewes bearing single lambs was less in all years for ewes lambing in July than for ewes lambing in September. More ewes were barren and fewer ewes had twins in July and consequently the mean fleece weights of all ewes from both groups were similar. Fleeces from ewes stocked at 10 ha-1 were lighter, shorter and finer than fleeces from ewes stocked at 5 and 7 1/2 ha-1, but the proportion of tender fleeces did not differ between the groups. Wool production of ewes stocked at 5 and 7 1/2 ha-1 increased from 1968 to 1970, whereas that of ewes at 10 ha-1 did not. This was associated with differences in pasture availability and composition. At 10 ewes ha-1 less pasture was present in winter and spring in 1970 than in 1968, whereas at the other stocking rates it was greater. In 1970 the density of weeds in autumn was greater and in spring more silver grass (Vulpia spp.) and less brome grass (Bromus spp.) was available at the high stocking rate.

Merino ewe and lamb performance in the Central Tablelands of New South Wales following joining in March-April or June-July

1988 ◽  
Vol 28 (5) ◽  
pp. 561 ◽  
Author(s):  
HL Davies ◽  
E Devaud
Keyword(s):  
New South ◽  
New South Wales ◽  
Subterranean Clover ◽  
Late Pregnancy ◽  
Stocking Rate ◽  
South Wales ◽  
Group Number ◽  
Nutritional Advantage ◽  
June July ◽  
Group 1

A March-April joining of Merino ewes was compared with a June-July joining in central New South Wales at a low stocking rate on subterranean clover based pastures over 3 years. In all years, ewes joined in June were heavier (P < 0.05) than ewes joined in March (55 v. 52 kg). Liveweights at the start of lambing and liveweight change from joining to lambing were also high and favoured the later lambing group. The proportion of ewes lambing (97% March v. 93% June) and proportion of ewes twinning (29% March v. 20% June) were not significantly different between the 2 groups, but consistently favoured the March-April joining. Perinatal mortality was low (9.4% March v. 7.1% June) and not significantly different between the 2 groups, but was consistently lower in the June joined group. Number of lambs weaned per 100 ewes joined was also not significantly different, but was higher each year in the March joined group (1 13% March v. 105% June). The growth rate of the lambs (both singles [24% greater, 248 v. 200 g/day] and twins [37% greater, 2 13 v. 155 g/day]) was consistently in favour of March joined ewes. Mean greasy fleece weights of the ewes were not significantly different between the 2 groups, but were in favour of the late joined group (4.83 v. 4.50 kg). Time of joining significantly affected liveweights and greasy and clean fleece weights of the progeny at the shearing in the year following their birth in favour of March joining. These data suggest that, despite a nutritional advantage to the ewes in late pregnancy and milder weather at lambing with a June-July joining, a March- April joining is the preferred option on the Central Tablelands of New South Wales.

Inbreeding depression in grazing Blackface sheep

1966 ◽  
Vol 8 (2) ◽  
pp. 261-266 ◽  
Author(s):  
J. M. Doney
Keyword(s):  
Birth Weight ◽  
Mortality Rate ◽  
Inbreeding Depression ◽  
Survival Rates ◽  
Late Pregnancy ◽  
Female Progeny ◽  
Mean Values ◽  
Natal Mortality ◽  
Made In ◽  
Birth Type

Four Scottish Blackface rams were mated with a group of their own daughters and a similar number of non-related ewes. The matings were made in three successive years. All ewes were maintained under normal hill conditions. Female progeny from the matings entered the ewe flock unculled. Records of birth type, birth weight, fleece and live-weights throughout life were obtained.Inbred lambs had lower mean values for all measured characters than did their non-inbred half-sibs and there was a greater number of apparently barren ewes amongst the flock ewes which were expected to produce inbred lambs. The inbred progeny, also maintained in the normal hill flock, showed a higher incidence of barrenness and lower lamb survival rates at all ages than did their non-inbred contemporaries in the same environment. In the final year of the observations, when the standard of nutrition during late pregnancy was raised, the neo-natal mortality rate in both groups was reduced.

Renovation of Yarloop subterranean clover pastures with Trikkala

1988 ◽  
Vol 28 (6) ◽  
pp. 737 ◽  
Author(s):  
DL Little ◽  
PE Beale
Keyword(s):  
Dry Matter ◽  
Plant Density ◽  
Subterranean Clover ◽  
Stocking Rate ◽  
Seed Reserves ◽  
Minimal Damage ◽  
Stocking Rates ◽  
Germinable Seed ◽  
Clover Scorch

Pastures containing the oestrogenic subterranean clover, Yarloop, were renovated and sown to Trikkala subterranean clover at the rate of 9 kg ha-1 germinable seed. The resultant pastures were continually grazed at either 7, 9 or 12 ewes ha for 6 years. Control Yarloop pastures were grazed similarly. Trikkala established at approximately 50 plants m-2 and represented 80% of all clover present in the year of sowing. Six years later Trikkala was successfully persisting at all stocking rates in terms of clover dry matter in spring (Trikkala 77%, Yarloop 23%), soil seed reserves in spring (Trikkala 450-1000 kg ha-1, Yarloop 300-450 kg ha-1) and plant density in spring (Trikkala 600-1000 plants m-2, Yarloop 200 plants m-2). Over the 6 years of the trial the proportion of Trikkala and Yarloop approached an equilibrium of 75% Trikkala to 25% Yarloop in all agronomic data collected. Compared with the control Yarloop pastures, the renovated Trikkala pastures maintained a greater clover percentage at all stocking rates. Available dry matter at the high stocking rate was consistently greater in the Yarloop pastures during winter and spring. At the low and medium stocking rates available dry matter tended to be greater in the Yarloop treatments for the first 2 years but was similar for both treatments in the latter 3 years. Clover scorch disease in the Yarloop pasture was controlled by spraying with a fungicide. Trikkala pastures were not sprayed and suffered minimal damage from the disease. Trikkala should perform better relative to Yarloop where clover scorch is a problem. It is concluded that Trikkala subterranean clover can successfully replace Yarloop subterranean clover in pastures previously dominated by Yarloop.

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