A study of Merino sheep grazing a cotton-bush (Kochia aphylla)–grassland (Stipa variabilis–Danthonia caespitosa) community on the riverine plain

1968 ◽  
Vol 19 (6) ◽  
pp. 947 ◽  
Author(s):  
JH Leigh ◽  
AD Wilson ◽  
WE Mulham
Keyword(s):  
In Vitro Digestibility ◽  
Stocking Rate ◽  
Merino Sheep ◽  
Dietary Crude Protein ◽  
Wool Growth ◽  
And Performance ◽  
Main Component ◽  
Stocking Rates ◽  
Low Rate

A study was made of Merino sheep continuously grazing a cotton-bush (Kochia aphylla R.Br.)–grassland (Stipa variabilis Hughes–Danthonia caespitosa Gaudich.) community over a 2 year period. Observations were carried out at two stocking rates (0.75 and 0.375 sheeplacre) and comparisons were made with plots from which K. aphylla had been mechanically removed. The aim of the study was to define the contribution made by K. aphylla (a drought-resistant chenopodiaceous shrub) to animal production and to examine the effects of the seasonal variation in composition, availability, and food value of the pasture on animal behaviour and performance. At the low rate of stocking K. aphylla contributed little to the diet of the sheep (max. 2% in autumn) despite its being at no time less than 20% of the forage available. At the high stocking rate its maximum contribution to the diet was 7% in late autumn. The major constituents of the diet in spring were the annuals Hedypnois rhagadioloides (L.) Willd. and Hypochoeris spp. and in summer the perennials Danthonia caespitosa and Kochia pentagona R.H. Anderson. D. caespitosa was also the main component during autumn at the low stocking rate but at the high stocking rate it was replaced in the diet by a high proportion of dead matter and Medicago burr. Seasonal variations in wool growth were greater at the high stocking rate than at the low rate, the lowest production occurring in autumn. Body weight and wool growth were not significantly altered by the presence of K. aphylla at either of the stocking rates. The lowest recorded value for dietary crude protein was 8.8%. Wool growth was closely related to the in vitro digestibility of the forage eaten and to the availability of green feed within the pasture.

A study of merino sheep grazing a bladder saltbush (Atriplex vesicaria) –cotton-bush (Kochia aphylla) community on the riverine plain

1969 ◽  
Vol 20 (6) ◽  
pp. 1123 ◽  
Author(s):  
AD Wilson ◽  
H Leigh ◽  
WE Mulham
Keyword(s):  
Perennial Grass ◽  
In Vitro Digestibility ◽  
Early Winter ◽  
Stocking Rate ◽  
Sheep Grazing ◽  
Seasonal Fluctuations ◽  
Merino Sheep ◽  
Wool Growth ◽  
Stocking Rates

A study was made of Merino sheep grazing a bladder saltbush (Atriplex vesicaria Hew. ex Benth.)–cotton-bush (Kochia aphylla R.Br.) community set stocked at three stocking rates (2.5, 1 .2, and 0.6 sheep/hectare) over a 3-year period. In spring the sheep preferred the perennial grass Danthonia caespitosa Gaudich. and the annuals Medicago polymorpha L. and Vulpia myuros (L.) K. C. Gmel. to the more abundant A. vesicaria. From summer to early winter the diet consisted mainly of A. vesicaria with the proportion of dead matter and Medicago burr increasing as the availability of A. vesicaria decreased. Seasonal fluctuations in wool growth were evident at all three stocking rates. Maximum wool growth rates occurred in spring when the nitrogen content (2.3%) and in vitro digestibility (65%) of the forage eaten was high. During autumn and early winter values for nitrogen (1.4%) and digestibility (50%) were lower and wool growth was at a minimum. At 0.6 sheep/ha animal productivity was maintained and there was little decline in the A. vesicaria population during the 3 years. Grazing eliminated all the A. vesicaria from the pasture stocked at 2.5 sheep/ha, and 98% at 1.2 sheep/ha. At these higher stocking rates the pasture proved incapable of maintaining the sheep for the 3-year period. The inability of A. vesicaria to recover after heavy or complete defoliation by grazing demonstrates the necessity of adopting a low stocking rate if the bush is to be retained.

Supplementary feeding pattern and rate of liveweight gain in winter-spring affect wool production of young Merino sheep on the south coast of Western Australia

1995 ◽  
Vol 35 (8) ◽  
pp. 1093 ◽  
Author(s):  
PT Doyle ◽  
TW Plaisted ◽  
RA Love
Keyword(s):  
Growth Rates ◽  
Management Strategies ◽  
Fibre Diameter ◽  
Supplementary Feeding ◽  
Stocking Rate ◽  
Merino Sheep ◽  
Wool Production ◽  
Wool Growth ◽  
Staple Strength ◽  
Stocking Rates

The effects of different supplementary feeding practices in summer-autumn and management strategies on green pasture on liveweight change, wool growth rate, annual wool production and wool characteristics of young Merino wethers were examined at 2 farms. The grain feeding treatments were lupins (L) or lupins and oats (LO) fed in amounts that were adjusted to try and maintain liveweight, or lupins and oats (LOG) fed at a higher rate. The objectives of liveweight maintenance or gain were not always achieved, but liveweight patterns differed between LOG compared with L or LO during summer-autumn. The sheep used at farm 1 were aged 4.5 months and liveweight 32 kg at the start of the experiment, while those at farm 2 were 6.5 months and liveweight 39 kg. The stocking rate in summer-autumn was 8 wethers/ha at both farms. During supplementation, sheep on LOG had a higher (P<0.05) liveweight change compared with those on L or LO (farm 1, 15 v. -8 g/sheep. day; farm 2, -35 v. -51 g/sheep. day) and clean wool growth rates (farm 1, 7.1 v. 6.4 g/sheep. day; farm 2, 5.1 v. 4.8 g/sheep.day). The sheep on LOG grew broader (P<0.05) wool than those on L or LO (farm 1, 19.0 v. 18.5 �m; farm 2, 21.7 v. 20.8 �m), and at farm 1 length was also greater (P<0.05) (114 v. 111 mm), while at farm 2 staple strength was greater (P<0.01) (22.9 v. 16.4 N/ktex). There were no significant differences in annual clean wool production. There were positive (P<0.01) relationships between staple strength and liveweight change to the time of minimum liveweight in summer-autumn. After green pasture on offer reached 500 kg DM/ha in autumn, different liveweight change patterns were achieved in 2 groups (LS, lower stocking rates; HS, higher stocking rates) of sheep at each farm by adjusting stocking rates. Within a farm, the LS and HS groups were comprised of equal numbers of sheep from each replicate of the supplementary feeding treatments. There were differences (P<0.05 to 0.01) in liveweight change between LS and HS (farm 1, 93 v. 72 g/day; farm 2, 127 v. 60 g/day), the differences being more pronounced at farm 2. The differential stocking rates at farm 2 resulted in differences in clean wool growth rates (P<0.01), in clean wool production (4.22 v. 4.53 kg, P<0.05), and fibre diameter (20.8 v. 21.4 �m, P<0.01), but there were no significant effects on staple length or strength. There were no significant effects of the supplementary feeding treatments imposed in summer-autumn on the responses to the stocking rate treatments on green pasture.

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.

Provision of high nitrogen roughage to sheep as a supplement to low nitrogen roughage

1975 ◽  
Vol 15 (74) ◽  
pp. 342 ◽  
Author(s):  
GE Robards ◽  
GR Pearce
Keyword(s):  
Poor Response ◽  
Control Group ◽  
In Vitro Digestibility ◽  
High Nitrogen ◽  
Wool Production ◽  
Wool Growth ◽  
Ad Libitum ◽  
Low Nitrogen ◽  
Basal Ration

Three feeding experiments and a digestibility study are reported in which the effects of supplementing low nitrogen roughages with roughages of high nitrogen content were studied. In each feeding experiment the effect of varying the frequency of supplementation was examined. During the first experiment intake of lucerne hay was greater (P < 0.05) than the intake of oaten hay and higher wool growth rates and liveweight changes were recorded. When the oaten and lucerne hays were alternated at intervals of one, two, three or four days, the average intake and rate of liveweight change was intermediate between the two previous levels, but the rate of wool production was similar to when lucerne hay was offered alone. There were no differences in total intake, clean wool production or liveweight change due to the frequency with which the two rations were alternated. The second experiment involved the feeding of a fixed quantity of lucerne hay with a. five times as much oaten hay or b. ad libitum oaten hay. The lucerne hay was given daily and every second, fourth and eighth days, and there was an unsupplemented control group. During the restricted feeding period frequent supplementation resulted in higher liveweight gain but there was no effect on wool growth. When oaten hay was provided ad libitum the poor response to supplementation and the large variation in intake within groups resulted in no significant differences in wool production or liveweight change between groups. The results of the third experiment indicate that the digestibility or degree of lignification of the basal ration affects the likelihood of a response to supplementation. It was shown that frequent supplementation of pasture hay resulted in higher intake, liveweight and wool production. On the other hand, substitute feeding with little change in animal production occurred when lucerne hay was offered to similar sheep consuming a basal ration of oaten hay which had a higher level of fibre and a lower in vitro digestibility than the pasture hay.

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.

The effect of frequency and time of cutting on the production and quality of a barley grass (Hordeum leporinum) dominant pasture

1967 ◽  
Vol 7 (29) ◽  
pp. 528 ◽  
Author(s):  
GE Robards ◽  
JH Leigh
Keyword(s):  
Nitrogen Content ◽  
Dry Matter ◽  
New South ◽  
In Vitro Digestibility ◽  
South Wales ◽  
Matter Production ◽  
Hordeum Leporinum ◽  
Main Component

A grazing experiment on a barley grass (Hordeum leporium Link) dominant pasture at Deniliquin, New South Wales, was carried out from May to November 1964. Monthly grazing of this pasture resulted in a greater dry matter yield of both green and total barley grass, and of crude protein, than when grazing occurred less frequently. The greatest stimulus to production was achieved when grazing occurred in August or September when the plants were approaching flowering. Rat's-tail fescue (Vulpia myuros (L.) K.C. Gmel), the other main component of the pasture, was not stimulated to greater total dry matter production by increasing the frequency of grazing. However, significantly more green fescue was harvested from areas grazed most frequently. The quality of both species, as estimated by nitrogen content and in vitro digestibility of barley grass and nitrogen content of fescue, was higher late in the season on the monthly grazed areas than on areas grazed less frequently.

The patterns of wool growth of Merino sheep grazing three Chenopod shrub rangelands.

1980 ◽  
Vol 2 (1) ◽  
pp. 53 ◽  
Author(s):  
RD Graetz
Keyword(s):  
Seasonal Variations ◽  
Experimental Period ◽  
Stocking Rate ◽  
Sheep Grazing ◽  
The West ◽  
Merino Sheep ◽  
Management Regime ◽  
Wool Growth ◽  
South Wales ◽  
Different Types

Annual fleece we~ghts and the seasonal varldtlon m uool growth of Peppm Merino wethers were measured for nearlv tlve years on three paddocks on the pastoral property 'Pme Creek' in the West Darlnlg distr~ct of Nea South Wales. The paddocks had the same stocking rate but encloyed different types of shrub rangelands - saltbush, pearl bluebush and degraded bluebush. Annual fleece weights varied between 4.0 and 5.3 kg (clean scoured) per sheep with no significant differences between the flocks in the different paddocks in any year. There were only small differences within years in the seasonal variations in wool growth for sheep from the three paddocks. Analysis of the relationships between ramfall and fleece weights during the experimental period and from 18 years of property records revealed that under the conservative stocking management regime of this property, wool cut per head \%as largely independent of the previous year's ramfali.

Influence of sward characteristics on grazing behaviour and growth of Hereford steers grazing tropical grass pastures

1978 ◽  
Vol 29 (1) ◽  
pp. 89 ◽  
Author(s):  
EA Chacon ◽  
TH Stobbs ◽  
MB Dale
Keyword(s):  
Nitrogen Content ◽  
Nutritive Value ◽  
In Vitro Digestibility ◽  
Relative Importance ◽  
Stocking Rate ◽  
Bite Size ◽  
Plant Parts ◽  
Digitaria Decumbens ◽  
Grazing Behaviour

Relationships between sward characteristics, grazing behaviour and growth of Hereford steers were studied on nitrogen-fertilized (378 kg ha-1 yr-1) Setaria anceps cv. Nandi and Digitaria decumbens swards continuously stocked at 4.3, 6.2 and 8.0 beasts ha-1 during five periods over 2 years. Availability of herbage, as measured by bite size, and nitrogen content and in vitro digestibility of herbage in the top of the swards were the two most important factors influencing the performance of steers. The relative importance of these factors varied between seasons, between stocking rate treatments and to a lesser extent between pasture species. The highest growth rates were measured on the leniently stocked pastures because steers were able to harvest feed easily (a large bite size) and could more readily select the more nutritious plant parts from the top of the sward. The swards were highly heterogeneous, and numerical analysis of data showed that at the same herbage yield, spatial distribution of herbage (leaf bulk density and leaf to stem ratio) and the nutritive value (in vitro digestibility and nitrogen content) of herbage greatly influenced the growth of steers. Cattle were unable to satisfy their feed requirements on some high quality but low-yielding swards, despite increasing grazing time to compensate for the small bites prehended (up to 707 min in 24 hr in spring). Consequently nitrogen and digestibility contents of extrusa samples were at times poor indicators of performance.

Nutritive evaluation of two strains of mature subterranean clover

1968 ◽  
Vol 8 (32) ◽  
pp. 295 ◽  
Author(s):  
ID Hume ◽  
M Somers ◽  
NR McKeown
Keyword(s):  
Dry Matter ◽  
Nutritive Value ◽  
Biological Significance ◽  
Subterranean Clover ◽  
In Vitro Digestibility ◽  
Voluntary Intake ◽  
Main Component ◽  
The Relationship

The relationship between the in vivo and in vitro digestibility of leguminous herbage was examined. Further studies were made using in vivo-in vitro digestibility estimations to compare the nutritive value to sheep of two strains (Yarloop and Woogenellup) of subterranean clover. The digestibilities of the main component parts (viz. stem, petiole, leaf, and burr) of the plants of each strain were also estimated in vitro. Digestibility differences between strains and between parts were examined on the basis of the chemical composition of their dry matter. Woogenellup was significantly more digestible than Yarloop, both in vivo and in vitro. Voluntary intake of Woogenellup was also significantly greater than that of Yarloop. The in vitro digestibility of stem did not differ significantly from that of petiole. Nor did the digestibility of leaf differ significantly from that of burr. However, the digestibility of stem and petiole together was greater than that of leaf and burr together. These findings are discussed in relation to their possible biological significance.

Observations on the regeneration of shrubs and woody forbs over a ten year period in grazed quadrats on Mileura Station, Western Australia.

1979 ◽  
Vol 1 (3) ◽  
pp. 215 ◽  
Author(s):  
SJJF Davies ◽  
TFM Walsh
Keyword(s):  
Species Diversity ◽  
Western Australia ◽  
Individual Species ◽  
Stocking Rate ◽  
Merino Sheep ◽  
Reverse Trend ◽  
Average Rainfall ◽  
Stocking Rates

Observations are reported on the regeneration of shrubs within grazed quadrats in inland Western Australia (26' 22's; 117' 20'~). The observations showed that in a ten year period of slightly above average rainfall, an increase in number of individual plants occurred in 24 out of 30 species of shrubs. No change occurred in four species and a decrease in numbers was observed in two species. Figures are given of the stocking rate of merino sheep on each quadrat in each year. Although no overall differences in amount of regeneration was observed in quadrats subjected to different stocking rates, within the range of rates occurring in this study (6.9 to 13.7 ha per sheep) individual species did show trends indicating different rates of regeneration under different stocking rates. Eremophila fraseri regenerated faster in quadrats experiencing high stocking rates than in those experiencing low ones and the reverse trend was shown by Solanum ashbyae and Acacia tetragonophylla. The Eremophila is considered unpalatable to stock whereas both the Solanum and the Acacia are eaten by sheep. Such trends could lead, eventually, to changes in species diversity in the area. The results of these observations suggest that the regeneration of rangeland shrubs is not incompatible with commercial stocking rates at Mileura.

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