The effect of stocking rate and deferred Autumn grazing of pasture on liveweight and wool production of Merino wethers in a Mediterranean-type climate

1976 ◽  
Vol 16 (79) ◽  
pp. 189 ◽  
Author(s):  
TH Brown
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
South Australia ◽  
Management Systems ◽  
Research Centre ◽  
Stocking Rate ◽  
Wool Production ◽  
Wool Growth ◽  
The Cost ◽  
Stocking Rates

Liveweight, seasonal wool growth rates, annual wool production, wool quality and hand feeding requirements were recorded for Merino wethers when autumn deferred or continuously grazed. The two management systems were compared at a series of eight stocking rates from 12.4 to 29.7 sheep per hectare for five years from 1967 to 1971 at the Kybybolite Research Centre, South Australia. Autumn deferment resulted in increased liveweight and wool growth rate during the months of June to September. However, liveweights and wool production under either management were similar for the remainder of the year. Because deferred grazing did not increase liveweights during the critical autumn period, and since hand feeding requirements were similar under either management system at the higher stocking rates, it is suggested that yearly stocking rates can not be increased by autumn deferment. Apart from the drought year of 1967, the continuously grazed sheep required little or no hand feeding up to 22.2 wethers per hectare. It is unlikely that the cost of hand feeding deferred sheep up to this stocking rate would be covered by the small increase in wool production. However, this would depend on the cost of conserved fodder and price received for the wool.

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.

Some factors which affect the liveweight change and wool growth of adult Corriedale wethers grazed at various stocking rates on perennial pasture in southern Victoria.

1981 ◽  
Vol 32 (2) ◽  
pp. 353 ◽  
Author(s):  
HA Birrell
Keyword(s):  
Growth Rate ◽  
Regression Analysis ◽  
Multiple Regression Analysis ◽  
Multiple Regression ◽  
Growth Rates ◽  
Stocking Rate ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Wool Growth ◽  
Stocking Rates

Monthly observations were taken on a number of animal and pasture characteristics during a 24-year study with adult Corriedale wethers which were grazed at 10, 15, 20 and 25 sheep ha-1. The seasonal patterns in all the observed parameters varied with the stocking rate. The more notable were the fluctuations in digestible organic matter intake (DOMI) which increased with stocking rate in summer (10 and 25 sheep ha-1 having 426 and 818 g DOMI d-1 respectively) and decreased in winter (655 and 448 g DOMI d-1). Both liveweight and wool growth rate (WGR) declined during autumn and increased in the spring at the two high stocking rates but not at the two low stocking rates. The herbage present and its relative growth rate both influenced the amount of herbage voluntarily eaten when the pasture was green. When the dry matter of herbage was < 1.5 t ha-1, the amount of herbage eaten increased as the yield and relative growth rates > 0.05 g g-1 d-1 increased. Sixty-two per cent of the variance in DOMI was accounted for. An exponential function fitted the overall data when relative growth rates were <0.05 g g-1 d-1. DOMI asymptoted at 740 g d-1 when herbage yields exceeded 2.0 t ha-1 (R2 = 0.70). Liveweight loss was very rapid in autumn at high stocking rates despite a high DOMI (c. 650g d-1). This was found, by using multiple regression analysis, to be associated with shearing stress, poor quality feed and long grazing times. In spring, on better quality feed, a long grazing time was associated with an enhanced liveweight response. A multiple regression analysis accounted for 73 % of the variance in WGR. The expression suggested that WGR increased and had a slightly curvilinear relationship with DOMI, was positively related to digestibility and negatively related to the daily time spent grazing. Wool growth slowed concurrently with liveweight losses, the magnitude of the decrease depending upon DOMI.

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.

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.

Ease of calving, growth and carcass characteristics of crossbred calves in the lower South East of South Australia

1983 ◽  
Vol 23 (122) ◽  
pp. 228 ◽  
Author(s):  
MPB Deland ◽  
RW Ponzoni ◽  
RW McNeil
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
South Australia ◽  
Carcass Characteristics ◽  
The Other ◽  
Research Centre ◽  
Slaughter Cattle ◽  
Calf Mortality ◽  
Lower South ◽  
Jersey Cows

Hereford, Charolais and Brahman sires were mated to Hereford, Shorthorn, Jersey and Friesian xshorthorn cows for four successive years from June 1969 at Struan Research Centre in South Australia. Assistance was given during 15 .9% of calvings resulting from Charolais sires, 6.8% resulting from Brahman sires and 2.1% from Hereford sires (differences statistically significant, P < 0 05). A greater percentage of Friesian x Shorthorn (13.8) than of Shorthorn (5.0) or Jersey (4 3) cows were assisted at birth (P< 0.05). There were no significant differences between the percentage of Hereford cows assisted (10.9) and that of any of the other dam breeds. There were no significant differences in calf mortality among sire breeds or among dam breeds. Charolais-sired calves were heavier at birth, 270,340 and 430 d old and had heavier (1 95 kg) carcasses with a smaller proportion of fat than Brahman- and Hereford-sired carcasses (180 and 167 kg respectively) at 430d old. Brahman-sired calves were heavier than Hereford-sired calves at birth, 370, 430 d old. However, they were significantly lighter at 270 d old. Hereford cows gave birth to significantly heavier calves than Shorthorn and Jersey cows but there were no clear differences due to dam breed in growth rates of calves, carcass weights or composition. It was concluded that the use of Charolais sires in the lower South East of South Australia can result in significant increases in the growth rate of slaughter cattle and in the production of leaner carcasses. Brahman sires did not exhibit clear advantages over Hereford sires. No definite conclusions could be drawn about the dam breeds examined in the study.

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.

Effects of nutrition and paring on linear hoof growth in sheep

1990 ◽  
Vol 41 (1) ◽  
pp. 197
Author(s):  
JL Wheeler ◽  
HI Davies ◽  
DA Hedges ◽  
PJ Reis
Keyword(s):  
Growth Rate ◽  
Ambient Temperature ◽  
Direct Effect ◽  
Growth Rates ◽  
Dry Matter ◽  
Latin Square ◽  
Residual Effects ◽  
Wool Production ◽  
Wool Growth ◽  
Nutritional Changes

Paring increased the linear hoof growth on the forefeet of Merino wethers by an average of 4.1% (P < 0.05) with a tendency for paring to promote faster growth on the medial digits. Effects of feeding these sheep with 400, 600, or 1000 g pelleted ration day-1 were assessed in a 4 X 4 Latin square design with 28-day periods using four measures of response. An extra (fifth) period was used to determine residual effects. The proportion of residual (carryover) to direct effect was much smaller for hoof growth than for wool. Hoof growth was not related to wool production. In another experiment, hoof growth rate of sheep increased from 103 to 136 8m day-1 when the intake of digestible dry matter was increased from 400 to 600 g day-1 (P< 0.001), and from 115 to 125 8m day -1 (P> 0.05) when the intake of digestible nitrogen was increased from 12 to 25 g day-1. Hoof growth rates of Merino wethers grazing native or sown pasture were not significantly affected by injecting DL-methionine daily into the abomasum. Hoof growth is not an appropriate index of wool growth. It may provide an easily measured, rapidly responsive and cumulative measure of nutritional changes, but its use cannot be recommended until more information is available on the factors that affect it and their interaction with ambient temperature.

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.

Comparative production of lean meat from Friesian bulls and steers over a range of nutritional planes at pasture

1981 ◽  
Vol 21 (110) ◽  
pp. 249 ◽  
Author(s):  
FJ Mickan ◽  
GW Thomas ◽  
SA Spiker
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Entire Range ◽  
Meat Production ◽  
Stocking Rate ◽  
Average Growth ◽  
Lean Meat ◽  
Manufacturing Trade ◽  
Stocking Rates

The growth rate and carcase characteristics of Friesian bulls and steers were compared when the animals were fed solely on pasture from 8 to 18 months of age. The animals were set stocked at rates ranging from 3.0 to 6.0 animals ha-1, so that average growth rates of the steers ranged from 0.87 to 0.57 kg d-1. All were slaughtered at 18 months of age for the manufacturing meat trade. For each additional animal per hectare the average daily liveweight gain of both bulls and steers was reduced by 0.1 0 kg d-1. However, at all stocking rates bulls maintained a 0.06 kg d-1 advantage over the steers. These results do not support the suggestion that as the plane of nutrition increases, so does the advantage in growth rate of the bulls over that of the steers. Seasonal liveweight gains of the two sex types and the effect of stocking rate on these are discussed. For each 0.1 0 kg d-1 increase in steer liveweight gain carcase weight per animal increased by 19 kg and the bulls produced 25 kg more carcase weight than the steers. As the plane of nutrition increased, the percentage of saleable meat produced by the steers was constant (66.2%) while that of the bulls increased (68.7%-72.3%). This trend was reversed for the percentage of fat trimmed out of the carcases. The fat trim of the bulls was 3.6% while that of the steers increased from 6.4% to 8.9%. Over the entire range of nutrition levels, bulls were superior to steers in all attributes considered necessary for the manufacturing trade. However, under Australian conditions, seemingly unjustifiable penalty rates for slaughtering and, to a lesser extent, farmer prejudice, severely restrict the use of young grazing bulls for lean meat production.

Nutrient partitioning in Merino rams with different wool growth rates

1994 ◽  
Vol 59 (1) ◽  
pp. 55-60 ◽  
Author(s):  
P. B. Cronjé ◽  
M. Smuts
Keyword(s):  
Growth Rate ◽  
Production Potential ◽  
Physiological Basis ◽  
Wool Production ◽  
Available Nutrients ◽  
Wool Growth ◽  
Nutrient Partitioning ◽  
Ad Libitum ◽  
Selection For ◽  
The Cost

AbstractThe aim of this experiment was to determine whether there is any physiological basis for concerns that selection for fleece mass may decrease fitness by increasing the partitioning of nutrients to wool at the expense of other body functions.Forty-five Merino rams (24 months old) were given food at an ad libitum and a maintenance level of nutrition. Animals were grouped into high, average or low clean fleece growth-rate categories on the basis of measurements made during the ad libitum feeding period. During ad libitum feeding, high producers grew proportionately 0·42 more clean fleece, and deposited proportionately 0·36 more energy and 0·42 more nitrogen (N) as greasy fleece than average producers. This was achieved by partitioning a higher proportion of N consumed to wool (0·08 v. 0·06), and not by increased energy or N retention. High producers adapted to the maintenance diet by decreasing clean wool growth rate proportionately by 0·32. There were no differences between high and average wool producers in clean wool growth rate or the percentage of N or energy intake partitioned to wool at the maintenance level of feeding. Although there were no differences in initial live mass between groups, low producers gained proportionately 0·45 more live mass during the experiment than average producers.It was concluded that Merino rams of high clean-wool production potential are not more efficient, but partition more of the available nutrients to wool production at the cost of body tissue deposition.

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