Effect of fertilizer nitrogen and feeding practices on productivity of Corriedale wethers grazing annual pasture in southern Victoria

1972 ◽  
Vol 12 (59) ◽  
pp. 589 ◽  
Author(s):  
IF Davis ◽  
MJ Sharkey
Keyword(s):  
Nitrogen Fertilizer ◽  
Carrying Capacity ◽  
Significant Interaction ◽  
Feeding Practices ◽  
Factorial Experiment ◽  
Fertilizer Nitrogen ◽  
Wool Production ◽  
Nitrogen Treatment ◽  
Stocking Rates

The effect of conserving hay and feeding it back in a feedlot, during which time grazing was deferred, and the application of nitrogen fertilizer to annual pasture (67 kg N ha-l yr-l) was studied in a factorial experiment. The study was carried out with Corriedale wethers at stocking rates of 10, 12, and 17 sheep a hectare from July, 1963 to December, 1966. There were three replicates of each treatment. There was no significant interaction between stocking rates and management treatments on wool production per head or per hectare. The deferred grazing, but not the nitrogen treatment, resulted in heavier liveweights and heavier fleece weights in 1964, 1965, and 1966. The differences were significant (P < 0.05) in 1964 and 1966. The carrying capacity over the three year period was increased by the deferred grazing treatment in association with nitrogen fertilizer. However, at current wool prices it is unlikely that the use of haymaking, deferment and nitrogen is economic.

Effect of stocking rate, fodder conservation and grazing management on the performance of wether sheep in south-west Victoria. 1. Wool production

1975 ◽  
Vol 15 (73) ◽  
pp. 173 ◽  
Author(s):  
AH Bishop ◽  
HA Birrell
Keyword(s):  
Major Effect ◽  
Factorial Experiment ◽  
Grazing Management ◽  
Maximum Response ◽  
Management Systems ◽  
Stocking Rate ◽  
Wool Production ◽  
The Third ◽  
South West ◽  
Stocking Rates

In a 4 x 4 x 3 factorial experiment lasting three years, the effects of stocking rate, fodder conservation and three grazing management systems (continuous, deferred and rotational) on the wool production of wethers grazing perennial pasture were assessed. The hay conserved on the plots was fed to the sheep in such a way that the quantities made and fed would balance over a period of years. At the highest rate of stocking some oats were fed in adverse seasons. Stocking rate had the major effect on wool production in all years. Improving wool production by fodder conservation was shown to depend on stocking rate, grazing management and the seasonal conditions. In some instances fodder conservation was shown to interact with stocking rate in a manner such that the maximum response tended to occur when smaller proportions of area were conserved as stocking rate increased. The implications of this interaction are discussed. Fodder conservation increased wool production in the continuous and rotationally grazed systems in all years, but did not in two of the three years with deferred grazing. The biggest increases in wool production due to fodder conservation occurred in the third year, the driest on record when a drought reserve was used. Wool production was also influenced by the grazing management. In alt-years there was a consistent interaction with stocking rate in which the highest wool production was produced in the rotational system at high stocking rates and in the deferred system at low stocking rates.

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.

Milk production from cows grazing on tropical grass pastures. 1. Effects of stocking rate and level of nitrogen fertilizer on the pasture and diet

1985 ◽  
Vol 25 (3) ◽  
pp. 505 ◽  
Author(s):  
TM Davison ◽  
RT Cowan ◽  
RK Shepherd ◽  
P Martin
Keyword(s):  
Protein Content ◽  
Milk Production ◽  
Nitrogen Fertilizer ◽  
Crude Protein ◽  
Dry Matter ◽  
Fertilizer Application ◽  
Stocking Rate ◽  
Crude Protein Content ◽  
Stocking Rates ◽  
Applied Nitrogen

A 3-year experiment was conducted at Kairi Research Station on the Atherton Tablelands, Queensland, to determine the effects of stocking rate and applied nitrogen fertilizer on the pasture yield and composition, diet selection by cows, and soil fertility of Gatton panic (Panicum maximum cv. Gatton) pastures. Thirty-two Friesian cows were used in a 4x2 factorial design: four stocking rates (2.0, 2.5, 3.0 and 3.5 cows/ha), each at two rates of fertilizer application 200 and 400 kg N/ha.year. The higher rate of fertilization increased the pasture green dry matter on offer at all samplings (P < 0.01); the increase ranged from 1 106 kg/ha in summer to 548 kg/ha in spring. Green dry matter decreased ( P< 0.0 1) with increasing stocking rate, with mean yields of 3736 and 2384 kg/ha at 2.0 and 3.5 cows/ha, respectively. Weed yields increased over the 3 years at the higher stocking rates for pastures receiving 200 kg N/ha.year. The crude protein content of leaf and stem increased with increasing stocking rate and amount of applied nitrogen fertilizer. Values ranged from 12.1 to 26.5% of dry matter (DM) in leaf and from 3.7 to 13.8% DM in stem. In leaf, sodium concentration (range 0.05-0.20% DM) was increased, while phosphorus concentration (range 0.21-0.44% DM) was decreased by the higher rate of fertilizer application. Plant sodium and phosphorus levels were inadequate for high levels of milk production. Dietary leaf content and crude protein contents were consistently increased by both a reduced stocking rate, and the higher rate of fertilization. Cows were able to select for leaf and at the lowest stocking rate, leaf in the diet averaged 38%; while the leaf content of the pasture was 20%. Dietary leaf content ranged from 38 to 57% in summer and from 11 to 36% in winter. Dietary crude protein ranged from 13 to 15% in summer and from 7 to 11% in winter and was positively correlated with pasture crude protein content and dietary leaf percentage. Soil pH decreased (P<0.05) from an overall mean of 6.3 in 1976 to 6.1 at 200 N and 5.8 at 400 N in 1979. Soil phosphorus status remained stable, while calcium and magnesium levels were lower (P<0.01) after 3 years.

Isotopic studies on the uptake of nitrogen by pasture grasses. II. Uptake of fertilizer nitrogen by Rhodes grass in posts

1964 ◽  
Vol 15 (6) ◽  
pp. 876 ◽  
Author(s):  
EF Henzell ◽  
AE Martin ◽  
PJ Ross ◽  
KP Haydock
Keyword(s):  
Linear Function ◽  
Total Nitrogen ◽  
Nitrogen Uptake ◽  
Nitrogen Fertilizer ◽  
Rhodes Grass ◽  
Fertilizer Nitrogen ◽  
Pasture Grasses ◽  
Isotopic Studies ◽  
Pretreatment Phase

Nitrogen uptake by Rhodes grass was a linear function of the quantity of 15NH4N03 applied for rates up to the equivalent of 400 lb N/ac, but the proportion of fertilizer nitrogen recovered in the plants fell significantly when the rate was increased to 800 lb N/ac. A nitrogen pretreatment equivalent to 200 lb N/ac had relatively little effect on the uptake of 15NH4N03 by the grass, despite the fact that it almost doubled the weight of roots in the pots when the 15NH4N03 was first applied. Over the range 0–400 lb N/ac, 84.1%% of added total nitrogen and 75.5% of added 15N was taken up by plants that received no nitrogen fertilizer during the pretreatment phase, and 80.3% of added total nitrogen and 71.9% of added 15N was taken up by plants that received a pretreatment of 200 lb N/ac. Fertilizer nitrogen was distributed between tops and roots in the ratio (averaged for the two pretreatments) of 5.2 : 1 for total nitrogen and 4.5 : 1 for 15N; these ratios were constant over the range 0–400 lb N/ac and were not significantly different.

Modelling the risk of different joining times and lamb sale policies

2014 ◽  
Vol 54 (10) ◽  
pp. 1694 ◽  
Author(s):  
S. M. Robertson ◽  
A. F. Southwell ◽  
M. A. Friend
Keyword(s):  
Carrying Capacity ◽  
Simulation Modelling ◽  
Management Systems ◽  
Stocking Rate ◽  
Gross Margin ◽  
Feed Resources ◽  
Systems Simulation ◽  
Gross Margins ◽  
The Impact ◽  
Stocking Rates

Month of joining and lamb sale strategy influence both the quantity and so value of lamb produced, and the feed required, so are important management decisions contributing to the profitability of sheep systems. Simulation modelling was used to evaluate the impact on gross margins of three lamb sale strategies for different months of joining and varying stocking rates. A flock of purchased Merino ewes producing crossbred lambs in southern Australia was modelled between 1971 and 2011. April joining produced higher gross margins than November or January only if the number of ewes per hectare was increased to potential carrying capacity. At the optimum stocking rate for each month of joining, three sale policies – a flexible lamb sale policy (where lambs were sold depending on seasonal conditions); selling lambs in December; or selling at 45-kg liveweight, all produced a similar mean gross margin, but the feed resources required were least using the flexible strategy (April-joined mean 195 ± 253 s.d. kg/ha for flexible compared with 219 ± 270 kg/ha if selling December or 1085 ± 459 kg/ha if sold at 45 kg). Mean gross margin differed between sale strategies by up to AU$66/ha if the optimal stocking rate was not used. These results suggest that the most advantageous lamb sale strategy will vary with both month of joining and stocking rate used, and should be considered when optimising sheep management systems.

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.

Sorghum — peanut crop sequences at Katherine, N.T.

1961 ◽  
Vol 1 (3) ◽  
pp. 144
Author(s):  
LJ Phillips ◽  
MJT Norman
Keyword(s):  
Nitrogen Content ◽  
Nitrogen Fertilizer ◽  
Grain Sorghum ◽  
Clay Loam ◽  
Fertilizer Nitrogen ◽  
Preceding Crop ◽  
Nitrogen Yield ◽  
Peanut Crop ◽  
Sorghum Grain ◽  
Crop Sequence

Between 1957-58 and 1960-61, a crop sequence experiment with grain sorghum and peanuts with and without nitrogen fertilizer was carried out on Tippera clay loam at Katherine, N.T. Neither crop was influenced by the crop grown two years before it. Peanuts showed no response to preceding crop or to nitrogen fertilizer. Sorghum grain yields were 77 per cent higher after peanuts than after sorghum, and sorghum stubble yields 56 per cent higher. Nitrogen fertilizer increased sorghum grain and stubble yield when the crop followed sorghum, but not when the crop followed peanuts. Nitrogen content of sorghum grain was higher after peanuts than after sorghum, and was also increased slightly by nitrogen fertilizer. Nitrogen yield of sorghum grain was almost twice as high in crops following peanuts than in crops following sorghum. Nitrogen fertilizer increased nitrogen yield of sorghum grain when the crop followed sorghum, but not when the crop followed peanuts.

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.

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