Effects of different stocking intensities in early life on the productivity of Merino ewes grazed as adults at two stocking rates. 3. Survival of ewes and their lambs, and the implications for flock productivity

1984 ◽  
Vol 24 (124) ◽  
pp. 57 ◽  
Author(s):  
JP Langlands ◽  
GE Donald ◽  
DR Paull
Keyword(s):  
Computer Model ◽  
Early Life ◽  
Adult Life ◽  
Stocking Rate ◽  
Cumulative Mortality ◽  
Severe Wear ◽  
Wool Production ◽  
Stocking Rates

A stocking rate of 20 sheep/ha in adult life was associated with greater mortality of ewes and their lambs than a stocking rate of 10 sheep/ha, but mortality was not affected by the nutrition of the ewes in early life. Survival of lambs born as twins to weaning was 42% at the high stocking rate and 72% at the low. Corresponding values for singletons were 73 and 87%. Differences in survival of singleton but not twin lambs were established during the first 5 d of life. Mortality of ewes was greater at a high stocking rate and by nine years of age approximately twice the number of ewes had died at the high as at the low stocking rate. Incisor wear and losses were greater in sheep stocked as adults at the high stocking rate, and within this flock was more marked in ewes reared at a low than in those reared at a high stocking rate. Severe wear and loss of incisor teeth were not correlated with cumulative mortality at 108 months. Data reported in this and in the two previous papers in this series were synthesized into a computer model which was used to predict wool production and the numbers of lambs and surplus ewes available for sale when culling age was varied from four to eight years. Wool production and the numbers of surplus sheep available for sale were predicted to be greater at the higher stocking rate with the exception of the number of surplus female lambs available from flocks in which their mothers were culled at six years or earlier.

Effects of different stocking intensities in early life on the productivity of Merino ewes grazed as adults at two stocking rates. 2. Reproductive performance

1984 ◽  
Vol 24 (124) ◽  
pp. 47 ◽  
Author(s):  
JP Langlands ◽  
GE Donald ◽  
DR Paull
Keyword(s):  
Reproductive Performance ◽  
Early Life ◽  
Unit Area ◽  
Adult Life ◽  
Stocking Rate ◽  
Area Basis ◽  
Lamb Survival ◽  
Stocking Rates

The reproductive performance of ewes subjected to four nutritional regimes from conception to 15 months of age was recorded from first lambing at 24 months until the seventh lambing. The ewes were grazed at 10 and 20 sheep/ha. The proportion of ewes which exhibited oestrus at their first mating was less in those which had grazed at a high stocking rate between 3 and 15 months, and fecundity was increased by 15% in subsequent years by a high plane of nutrition between conception and 3 months of age, but only when ewes were grazed at a low stocking rate as adults. Ewes stocked at 10 sheep/ha weaned 50% more lambs than ewes stocked at 20 sheep/ha in adult life, but the more heavily stocked ewes weaned approximately 33% more lambs on a unit area basis. Approximately half the variability in the number of lambs weaned per ewe available for service was associated with variability in lamb survival. Relationships between the proportion of ewes showing oestrus, fecundity, survival of lambs, overall reproductive performance and liveweight of ewes are presented.

Effects of different stocking intensities in early life on the productivity of Merino ewes grazed as adults at two stocking rates. 1. Wool production and quality, lamb growth rate, and size and liveweight of ewes

1984 ◽  
Vol 24 (124) ◽  
pp. 34 ◽  
Author(s):  
JP Langlands ◽  
GE Donald ◽  
DR Paull
Keyword(s):  
Fibre Diameter ◽  
Adult Life ◽  
Stocking Rate ◽  
Wool Production ◽  
Ewe Lambs ◽  
Subjective Assessments ◽  
Early Adult Life ◽  
Treatment Trends ◽  
Stocking Rates ◽  
Lamb Growth

Ewe lambs born to Merino ewes grazed at 10 or 20 sheep/ha were weaned at three months (L-, H-) and randomized to low or high stocking rate treatments (-L, -H) until 15 months old. Ewes from each of the four groups (LL, LH, HL and HH) then grazed at 10 or 20 sheep/ha until nine years old. Liveweight in early adult life and some body dimensions were reduced by a low plane of nutrition during rearing. The differences in liveweight declined with time and were not significant after 2% years in ewes stocked as adults at 10/ha or after 5% years in ewes stocked at 20/ha. Wool production and growth rates of lambs were reduced when ewes were stocked at the high stocking rate, but were not affected by rearing treatment. Wool production per sheep was about 30% greater at the lower stocking rate but about 33% less when expressed on a unit area basis. Fibre diameter and fleece length were reduced by a high stocking rate in adult life but were not affected by rearing treatment. Yield was not affected by stocking rate at any time. A number of subjective assessments of wool quality were also recorded; quality declined at a high stocking rate but was not affected by rearing treatment. Trends in wool production and quality with age of ewe are reported.

The intake and production of lactating Merino ewes and their lambs grazed at different stocking rates

1977 ◽  
Vol 28 (1) ◽  
pp. 133 ◽  
Author(s):  
JP Langlands
Keyword(s):  
Organic Matter ◽  
Milk Production ◽  
Metabolizable Energy ◽  
Milk Consumption ◽  
Total Organic Matter ◽  
Stocking Rate ◽  
Wool Production ◽  
Maintenance Requirement ◽  
Stocking Rates

Grass and milk consumption and liveweight changes of lambs grazed at stocking rates ranging from 9 to 35 sheep/ha were measured during a 105 day lactation. Grass consumption and wool production of their mothers and of similar ewes without lambs were also determined. The forage and total organic matter intakes of the lamb increased with time while milk consumption declined; all three variables were negatively correlated with stocking rate. The intake of the ewe and its liveweight gain were not sensitive to increasing stocking rate, but wool production declined at higher stocking rates. The maintenance requirement of the ewes was estimated to be 218 kJ metabolizable energy/kg liveweight, and the efficiency with which metabolizable energy was utilized for milk production was 66%. Lactation increased the intake of the ewe but reduced its wool production.

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.

Correction - Integrating sheep and wheat production: effect of substituting wheat production for pasture on the wool production of wethers

1974 ◽  
Vol 14 (69) ◽  
pp. 454
Author(s):  
DJ Cannon
Keyword(s):  
Stocking Rate ◽  
Dual Use ◽  
Wheat Production ◽  
Wool Production ◽  
Production Effect ◽  
Stocking Rates

The wool production and liveweight of Corriedale wethers was measured when both stocking rate and the proportion of land to wheat and pasture varied. The nominal stocking rates (R) were 6.8, 8.6, 10.5, 12.4 and 14.2 wethers ha-1, and the proportion sown to wheat was 0, 15 or 30 per cent. Clean wool production per head declined linearly with increase in stocking rate and the proportion of land sown to crop. Generally both maxima and minima liveweights declined with increase in cropping and minima liveweights with increase in stocking rate. The effect of cropping on wool production was attributed to the increased stocking rate on the uncropped portion of land during the period when the cropped area was unavailable to grazing. 'Average' stocking rates per ha (S) were calculated on the basis of the proportion of land to crop and the fraction of the year stubbles were available for grazing. S was found to be a more useful measure of stocking rate than R, in a system of dual use of land.

Integrating sheep and wheat production: effect of substituting wheat production for pasture on the wool production of wethers

1974 ◽  
Vol 14 (69) ◽  
pp. 454
Author(s):  
DJ Cannon
Keyword(s):  
Stocking Rate ◽  
Dual Use ◽  
Wheat Production ◽  
Wool Production ◽  
Production Effect ◽  
Stocking Rates

The wool production and liveweight of Corriedale wethers was measured when both stocking rate and the proportion of land to wheat and pasture varied. The nominal stocking rates (R) were 6.8, 8.6, 10.5, 12.4 and 14.2 wethers ha-1, and the proportion sown to wheat was 0, 15 or 30 per cent. Clean wool production per head declined linearly with increase in stocking rate and the proportion of land sown to crop. Generally both maxima and minima liveweights declined with increase in cropping and minima liveweights with increase in stocking rate. The effect of cropping on wool production was attributed to the increased stocking rate on the uncropped portion of land during the period when the cropped area was unavailable to grazing. 'Average' stocking rates per ha (S) were calculated on the basis of the proportion of land to crop and the fraction of the year stubbles were available for grazing. S was found to be a more useful measure of stocking rate than R, in a system of dual use of land.

A Comparative Study of Sheep Grazing a Semi-Arid Saltbush Pasture in Two Condition Classes.

1986 ◽  
Vol 8 (1) ◽  
pp. 46 ◽  
Author(s):  
RD Graetz
Keyword(s):  
Nutritional Value ◽  
Body Weight Gain ◽  
Landsat Imagery ◽  
Stocking Rate ◽  
Sheep Grazing ◽  
Wool Production ◽  
Broken Hill ◽  
Wool Growth ◽  
Stocking Rates

Measurements were made of the wool growth, body weight gain and diet of sheep grazing a saltbush pasture near Broken Hill, N.S.W. The experiment utilized a fenceline contrast in saltbush (Atriplex vesrcarra) density that was visible on Landsat imagery. It ran for five years (1976-1981) with a design of two pasture types by two stocking rates. Fleece weights varied from 3.9-6.0 kg/head and wool production from 0.6-2.9 kg/ha. Neither wool production per head nor bodyweight were substantially affected by stocking rate or pasture type. The composition and quality of the diets selected by sheep on both pastures were identical and of high nutritional value indicating their capability to accommodate differences in pasture composition. Pasture quality was not limiting between stocking rates or determined by the abundance of saltbush. Changes in pasture composition resulting from grazing and exclosure were small and of no significance.

An evaluation of cereal stubbles for sheep production

1976 ◽  
Vol 27 (6) ◽  
pp. 881 ◽  
Author(s):  
JG Mulholland ◽  
JB Coombe ◽  
M Freer ◽  
WR McManus
Keyword(s):  
Plant Material ◽  
Green Plant ◽  
Animal Production ◽  
Stocking Rate ◽  
Mineral Supplement ◽  
Wool Production ◽  
Sheep Production ◽  
One Year ◽  
Cereal Residues ◽  
Stocking Rates

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.

An evaluation of grazing oats for grain and wool production in north-eastern Victoria

1978 ◽  
Vol 18 (91) ◽  
pp. 202 ◽  
Author(s):  
DJ Cannon ◽  
MJ Sharkey ◽  
PT Stewart
Keyword(s):  
Land Use ◽  
Grazing Intensity ◽  
Stocking Rate ◽  
Wool Production ◽  
North East ◽  
System 2 ◽  
Plot Area ◽  
The Mean ◽  
System 1 ◽  
Stocking Rates

Oat yields and wool production of Merino wethers were measured at five stocking rates in five systems of land use in each of two years, 1971 and 1972, in north-east Victoria. Nominal stocking rates were 6.8, 8.6, 10.5, 12.4 and 14.2 sheep ha-1. The production at each stocking rate was compared in the following systems: 1, all pasture; 2, and 3. pasture grazed year long with oats grazed in winter and oat stubbles in summer on 15 per cent (system 2) or 30 per cent of the plot area (system 3) ; 4. and 5. pasture grazed throughout with oat stubbles grazed in summer but crops not grazed during the growing season and crops comprised either 15 per cent (system 4) or 30 per cent of the plot area (system 5). In 1971 the rainfall of 540 mm was sufficient to produce a harvestable oat crop and to maintain sheep on all plots without supplements. The mean oat yield of 2.04 � 0.01 t ha-1 for system 3 far exceeded that of the more heavily grazed crops in system 2 (1.44-0.05) or of ungrazed crops in systems 4 and 5 (1.44i-0.07). Clean wool production per head from each system was compared in terms of an 'average' stocking rate S which accounted for variation in grazing intensity throughout the year inherent in systems 2, 3, 4, 5. In 1971 clean wool production kg-1 declined with increase in average stocking rate in all systems but the mean of the four dual land use systems did not differ from the all pasture system (1). 1972 was a drought year with only 330 mm of rain, oat crops failed to produce grain and were grazed from October. The wool production of sheep on systems 2 to 5 was greater than that of sheep at equivalent average stocking rates on the all pasture system. Growing oats for grazing and grain in association with wool production would appear to be more profitable than wool production alone. Light grazing of oats in winter may increase oat yield but more information is needed in relation to seasonal variation and oat variety.

Stocking intensity and pastoral production: III. Wool production, fleece characteristics, and the utilization of nutrients for maintenance and wool growth by Merino sheep grazed at different stocking rates

1973 ◽  
Vol 81 (2) ◽  
pp. 211-218 ◽  
Author(s):  
J. P. Langlands ◽  
I. L. Bennett
Keyword(s):  
Live Weight ◽  
Early Spring ◽  
Metabolizable Energy ◽  
Late Winter ◽  
Stocking Rate ◽  
Wool Production ◽  
Digestible Organic Matter ◽  
Unit Increase ◽  
Rate Of Decline ◽  
Stocking Rates

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.

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