Cadmium concentrations in liver, kidney and muscle in Australian sheep and cattle

1988 ◽  
Vol 28 (3) ◽  
pp. 291 ◽  
Author(s):  
JP Langlands ◽  
GE Donald ◽  
JE Bowles
Keyword(s):  
Western Australia ◽  
Australian Bureau ◽  
Human Consumption ◽  
Stocking Rate ◽  
Geographical Regions ◽  
Liver And Kidney ◽  
Australian Sheep ◽  
Highly Correlated ◽  
Stocking Rates ◽  
Improved Pasture

Cadmium (Cd) concentrations in 1663 liver, 1779 kidney and 2526 muscle samples were measured in a residue survey organised by the Australian Bureau of Rural Science at meatworks throughout Australia. Cadmium concentrations in livers and kidneys were also determined in sheep ranging in age from newly born to 112 months of age which had been grazed throughout life at high or low stocking rates on an improved pasture dressed annually with superphosphate. Concentrations of Cd in the residue survey averaged (with median) 0.30 (0.11), 0.96 (0.28) and 0.03 (0.01) mg/kg freshweight in ovine liver, kidney and muscle respectively; the corresponding values in cattle were 0.18 (0.08), 0.65 (0.24) and 0.03 (0.01) mg/kg. Concentrations in liver and kidney were greater in older than in younger animals, at high than at low stocking rates, and in South and Western Australia than in other States. Cadmium concentrations increase with age because ruminants are born with a low Cd burden, and much of the Cd ingested and absorbed thereafter is retained as Cd-metallothionein in the liver and kidney. It is postulated that differences in Cd levels between geographical regions, species and stocking rate are partially due to the consumption of soil that had been fertilised with superphosphate containing Cd. Hepatic and renal Cd concentrations were highly correlated and were assumed to reflect Cd intake; correlations with copper concentrations were generally small. Eight per cent of kidneys exceeded maximum permissible Cd concentrations for human consumption (2.5 mg/kg), but only 2% of liver and 1% of muscle samples exceeded the statutory maxima (1.25 and 0.2 mg/kg respectively).

The cage method of sampling to assess herbage mass and herbage consumed on annual rangeland vegetation

1988 ◽  
Vol 10 (1) ◽  
pp. 6
Author(s):  
BB Zahran ◽  
AM Holm ◽  
WR Stern ◽  
WA Loneragan
Keyword(s):  
Western Australia ◽  
Soil Type ◽  
The Other ◽  
Soil Types ◽  
Stocking Rate ◽  
Sheep Grazing ◽  
Annual Species ◽  
Short Supply ◽  
Seasonal Trends ◽  
Stocking Rates

The cage method of sampling vegetation was used to estimate herbage mass and herbage consumed by sheep, grazing a pasture dominated by annual species, near Camawon, Western Australia. Using paired quadrats (2m x lm), one caged and the other open, herbage mass and herbage consumed were measured at five stocking rates on two soil types, on eight occasions between December 1983 and January 1985. The data were highly variable; nevertheless, some effects of season, soil type and stocking rate could be observed. The results showed clear seasonal trends. Some soil type x stocking rate interactions were detected during the dry periods of the year when herbage mass was low. Generally, the cage method tended to over-estimate herbage consuped. Sheep consumed approximately 119 to 116 of the available herbage at low and high stocking rates respectively when feed was plentiful; when feed was in short supply the corresponding figures were approximately 113 and 1/2. The limitations of the method are discussed and some suggestions made concerning its applicability in rangeland studies.

Relations between stocking rate, environment and scorch disease on grazed subterranean clover pasture in Western Australia

1982 ◽  
Vol 22 (116) ◽  
pp. 182 ◽  
Author(s):  
WK Anderson ◽  
RJ Parkin ◽  
MD Dovey
Keyword(s):  
Western Australia ◽  
Chemical Control ◽  
Dry Matter ◽  
Disease Incidence ◽  
Subterranean Clover ◽  
Stocking Rate ◽  
Disease Symptoms ◽  
Sheep Production ◽  
Stocking Rates ◽  
Clover Scorch

The effects of weather on clover scorch disease caused by Kabatiella caulivora, the effects of the disease on pasture and sheep production, and the effect of sheep stocking rate (6, 8, 10 and 12 sheep/ha) on the disease were studied in a field experiment over three seasons near Albany, Western Australia. Spraying with benlate was used to control clover scorch on some treatments. Mean temperatures during the period when symptoms of the disease increased were in the range 11-17�C. Rainfall was frequent each year during the same period. The rapid increase in disease symptoms was observed when pasture dry matter on offer was approximately 2500 kg/ha. Disease symptoms decreased during a period of water stress of the pasture. Clover scorch disease had no consistent effect on pasture or animal production except that pasture dry matter on offer in spring was reduced in the unsprayed treatments at the lower stocking rates in the second two years. Higher stocking rates (10 and 12 sheep/ha) reduced the level of clover scorch symptoms without the use of chemical control with benlate. At the period of peak scorch symptoms a stocking rate of 10 sheep/ha reduced disease incidence by 20-35% compared with 6 sheep/ha in unsprayed plots. Increased sheep stocking rates are suggested as a possible alternative to chemical control or replacement of susceptible strains of subterranean clover in grazed pasture.

Effects of genotype, sex and stocking rate on postweaning efficiency and value-adding potential at turnoff of weaners grazing improved pasture in the Douglas Daly region of the Northern Territory

2007 ◽  
Vol 47 (11) ◽  
pp. 1272 ◽  
Author(s):  
T. J. Schatz ◽  
P. E. R. Ridley ◽  
D. J. M. La Fontaine ◽  
M. N. Hearnden
Keyword(s):  
Weight Gain ◽  
East Asian ◽  
Northern Territory ◽  
Stocking Rate ◽  
Stocking Rates ◽  
Improved Pasture ◽  
The Way

An experiment was undertaken to establish the effects of genotype, sex and stocking rate on postweaning growth and value-adding potential at turnoff of weaners grazing improved pasture in the Douglas Daly region of the Northern Territory, Australia. The growth of 27 steer and 27 heifer weaners of four genotypes was studied each year for 4 years (i.e. n = 216 animals per year). Animals from each group were run at one of three stocking rates. The cattle were weighed monthly and fat depth was measured ultrasonically at the end of the postweaning year. Genotype had no significant effect on weight gain but one-quarter Charolais × three-quarters Brahman and Droughtmaster animals were significantly (P < 0.0001) leaner than Brahman (purebred and commercial) cattle at the end of the postweaning year. Steers grew more (12%; P < 0.0001) and were leaner (2.6 mm less P8 fat depth; P < 0.0001) than heifers. Animals that grazed at lower stocking rates gained more weight (P < 0.0001) but were not significantly fatter than those at higher stocking rates. The way these factors can be used to produce leaner animals with more value-adding potential for South-East Asian feedlots is discussed.

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.

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.

Management of grazing systems

1989 ◽  
pp. 117-122 ◽  
Author(s):  
J. Hodgson
Keyword(s):  
Management Practices ◽  
Management Control ◽  
Grazing Management ◽  
Relative Importance ◽  
Stocking Rate ◽  
Pastoral Systems ◽  
Starting Point ◽  
Alternative Means ◽  
Grazing Systems ◽  
Stocking Rates

Recent assessments of the relative importance of stocking rate. stocking policy and grazing management on the output from pastoral systems are used as a starting point to argue the need for objective pasture assessments to aid control of livestock enterprises to meet production targets. Variations in stocking rates, stocking policy and other management practices all provide alternative means of control of pasture conditions which are the major determinants of pasture and animal performance. Understanding of the influence of pasture conditions on systems performance should provide a better basis for management control and for Communication between farmers, extension officers and researchers. Keywords: Stocking rate, pasture condition, pasture cover

scholarly journals 87 Evaluation of two stocking rates for grazing heifers on mixed sward native warm-season grass pastures in the Black Belt Prairie region

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 27-27
Author(s):  
Jane A Parish ◽  
Kalisha C Yankey ◽  
Libby S Durst
Keyword(s):  
Nutritive Value ◽  
Bos Taurus ◽  
Warm Season ◽  
Stocking Rate ◽  
Sorghastrum Nutans ◽  
Study Objective ◽  
Little Bluestem ◽  
Year Effect ◽  
Plant Persistence ◽  
Stocking Rates

Abstract Optimal use of native warm-season grasses in pasture systems involves stocking grazing livestock at suitable rates. The study objective was to evaluate forage nutritive value and heifer ADG at two stocking rates on mixed-sward pastures of big bluestem (Andropogon gerardi Vitman), little bluestem (Andropogon scoparius), and indiangrass (Sorghastrum nutans L.). Pastures (3 replications) were stocked for 56 d during June and July in 2 yr with crossbred (Bos taurus) heifers (n = 24 heifers/year) stratified by initial BW (288.3 ± 1.7 kg) to one of two continuous stocking rates: 1.9 heifers/ha (HIGH) and 1.2 heifers/ha (LOW). Mean forage nutritive values on a DM basis were not different between HIGH and LOW stocking rates, respectively, for CP (7.0 ± 0.2% vs 6.7 ± 0.2%; P = 0.27), ADF (41.0 ± 0.6 vs. 41.4 ± 0.6; P = 0.64), NDF (69.9 ± 0.5 vs. 68.7 ± 0.5; P = 0.09), or relative feed value (RFV) (76.0 ± 1.0 vs. 76.9 ± 1.0; P = 0.53). There was a year effect (P &lt; 0.01) and stocking rate x day effect (P &lt; 0.01) for TDN. At LOW, TDN decreased from day 0 to day 28 (P = 0.02) and day 28 to day 56 (P = 0.02). At HIGH, TDN decreased (P &lt; 0.01) from day 0 to day 28 but remained steady until day 56 (P = 0.21). There was a stocking rate x day interaction (P &lt; 0.01) with ADG: LOW day 28 to 56 (1.20 ± 0.08 kg/day), HIGH day 0 to 28 (0.89 ± 0.08 kg/day), HIGH day 28 to 56 (0.44 ± 0.08 kg/day), and LOW day 0 to 28 (0.30 ± 0.08 kg/day). Further assessment of cattle ADG using more divergent stocking rates and plant persistence measures is warranted to inform ideal native grass stocking rate recommendations.

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.

scholarly journals Compost as an Option for Sustainable Crop Production at Low Stocking Rates in Organic Farming

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1078
Author(s):  
Christopher Brock ◽  
Meike Oltmanns ◽  
Christoph Matthes ◽  
Ben Schmehe ◽  
Harald Schaaf ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Farming ◽  
Crop Production ◽  
Potassium Sulfate ◽  
Control Treatment ◽  
Stocking Rate ◽  
Internal Resources ◽  
Compost Application ◽  
Stocking Rates

Mixed-crop-livestock farms offer the best conditions for sustainable nutrient management in organic farming. However, if stocking rates are too low, sustainability might be threatened. Therefore, we studied the development of soil organic matter and nutrients as well as crop yields over the first course of a new long-term field experiment with a mimicked cattle stocking rate of 0.6 LU ha−1, which is the actual average stocking rate for organic farms in Germany. In the experiment, we tested the effects of additional compost application to improve organic matter supply to soils, and further, potassium sulfate fertilization for an improved nutrition of fodder legumes. Compost was made from internal resources of the farm (woody material from hedge-cutting). Soil organic matter and nutrient stocks decreased in the control treatment, even though yield levels, and thus nutrient exports, were comparably low. With compost application, soil organic matter and nutrient exports could be compensated for. At the same time, the yields increased but stayed at a moderate level. Potassium sulfate fertilization further improved N yields. We conclude that compost from internal resources is a viable solution to facilitate sustainable organic crop production at low stocking rates. However, we are aware that this option does not solve the basic problem of open nutrient cycles on the farm gate level.

The design and interpretation of experiments to study animal production from grazed pasture

1968 ◽  
Vol 71 (3) ◽  
pp. 327-335 ◽  
Author(s):  
J. B. Owen ◽  
W. J. Ridgman
Keyword(s):  
Simple Model ◽  
Unit Area ◽  
Personal Communication ◽  
Animal Production ◽  
Stocking Rate ◽  
Grazed Pasture ◽  
Stocking Rates ◽  
Pasture Productivity

SUMMARYExperiments designed to assess differences between treatments in pasture productivity as measured by the production of animals are complicated by the stocking rates chosen. The paper attempts toderive a simple model relating production per animal and production per unit area to stocking rate for meat animals, based on biological considerations.A method is proposed which would allow meaningful grazing experiments to be carried out employing only one stocking rate, thus considerably reducing the expense of this type of experimentation.The model is applied to some recent data obtained by Hodgson (1966) and Appleton (1967, personal communication).

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