Seasonal diet selection by ewes grazing within contrasting grazing systems

2017 ◽  
Vol 57 (9) ◽  
pp. 1824 ◽  
Author(s):  
Felicity Cox ◽  
Warwick B. Badgery ◽  
David R. Kemp ◽  
Gaye Krebs
Keyword(s):  
New South ◽  
Underlying Mechanism ◽  
Diet Selection ◽  
Grazing Management ◽  
Management Systems ◽  
Non Invasive ◽  
South Wales ◽  
Continuous Grazing ◽  
Grazing Systems ◽  
The Relationship

Grazing management systems seek to control the relationship among animals, plants and soil by regulating the number of animals and the duration and location of animals. A greater understanding of the diet selection and activity of livestock within grazing systems will assist producers to make informed management decisions about their management within complex pastures. In the present paper, differences in the diet quality, selection and activity of ewes managed within contrasting systems (continuous-grazing (CG) and an intensive (20-paddock) rotational-grazing (RG) system) within a native pasture in the Central Tablelands of New South Wales, using non-invasive methodologies, are described. During two time periods (late spring and early autumn), the animals grazing within the CG system consumed a diet of higher quality and spent less time active than did those within the RG system. These differences resulted in higher individual animal production of CG animals that were able to maintain the herbage of preferred areas in a vegetative and highly nutritious state. The grazing animals selected the green herbage of higher quality than the average pasture and adjusted their selection seasonally. An underlying mechanism driving selection is the green : dead ratio of the herbage. Practically the results indicated that the green : dead ratio (or greenness) of herbage may provide a management trigger to enhance the production of animals grazing within a RG system, in particular during periods of higher requirement.

Goat and Sheep Grazing in Shrub-Infested Semi-arid Woodlands of New South Wales.

1986 ◽  
Vol 8 (2) ◽  
pp. 140 ◽  
Author(s):  
BH Downing
Keyword(s):  
Animal Species ◽  
New South ◽  
Economic Implications ◽  
Dietary Preferences ◽  
South Wales ◽  
Continuous Grazing ◽  
Local Observation ◽  
Grazing Systems ◽  
Western Division

Examination of data on dietary preferences of sheep, goats and cattle suggests that different grazing systems are desirable for each of the three major woodland types (belah-rosewood, mulga, poplar box) examined. Competition for herbs, frequently palatable to all animal species, indicates that goats and sheep are unsuitable for joint use either in heavily wooded country or where annual herbaceous production is less than 200 kg-ha. Supplementary feeding, fire and judicious stocking are proposed as a strategy for inducing goats to eat a proportion of unpalatable shrubs. The literature provides little helpful information on how rangelands in the Western Division should be managed. No reports are given on comparisons of grazing systems, such as rotational grazing, rotational resting, and continuous grazing. No guidance is given on grazing after burning of the rangeland. Recommendations are generally against the use of goats for control of woody plants, whereas local observation shows this to be an apparently effective practice. The recommendations are mostly based on experimental procedures which, although suitable for detecting animal dietary preferences in the short term, are less appropriate for investigation of the effects of grazing on range condition in the long term. Some suggestions are made towards a different approach for: investigating the effects of grazing by sheep and goats on rangeland condition, and the economic implications of this in terms of animal production.

Sustainable grazing systems for the Central Tablelands of New South Wales. 5. A bioeconomic framework for assessing the long-term economic benefits of grazing management tactics and implications for sustainability

2006 ◽  
Vol 46 (4) ◽  
pp. 495 ◽  
Author(s):  
R. E. Jones ◽  
P. M. Dowling ◽  
D. L. Michalk ◽  
W. McG. King
Keyword(s):  
Programming Model ◽  
New South ◽  
New South Wales ◽  
Economic Benefits ◽  
Grazing Management ◽  
South Wales ◽  
Grazing Systems ◽  
Sustainable Grazing ◽  
Management Tactics

There have been significant declines in the perennial grass (PG) content in native and sown pastures across temperate Australia. Not only has this reduced agricultural productivity, it has contributed to more serious degradation, such as loss of soil and biodiversity, decreasing water quality, and dryland salinity caused by rising watertables. Results from the Sustainable Grazing Systems Key Program (SGS) research undertaken at Carcoar on the Central Tablelands of New South Wales were reported by Michalk et al. (2003). This research indicated that grazing management tactics can be used to manipulate pasture composition, thereby changing animal production and water-use patterns. The main grazing tactic investigated was termed a summer grazing rest, where resting was imposed in late spring if PG composition was <50%. Reported in this present paper is an economic framework for valuing the long-term benefits of grazing management tactics. The framework involves the development of a bioeconomic modelling system that links a dynamic programming model with biophysical models for water and environmental processes, soil fertility, pasture growth, livestock energy requirements and the change in pasture species composition. The study concludes that long-term economic returns are improved by strategies, e.g. a summer rest, that lead to an increase in PG composition over time. The study also determined that environmental factors, such as deep drainage, runoff and soil loss, are reduced as perenniality is increased.

Effects of four grazing management systems on the production and persistence of dryland lucerne in central western New South Wales

1973 ◽  
Vol 13 (62) ◽  
pp. 259 ◽  
Author(s):  
H Brownlee
Keyword(s):  
Dry Matter ◽  
New South ◽  
New South Wales ◽  
Grazing Management ◽  
Management Systems ◽  
Rotational Grazing ◽  
South Wales

During an experiment conducted for eighteen months at Condobolin, New South Wales, the production and persistence of dryland lucerne grazed by Merino wethers at 10 ha-1 yr-1 were measured under set stocking and three rotational grazing treatments differing in length of spelling period between grazings (grazed one week in four, six or eight weeks). The results showed that although dry matter availability and lucerne survival increased with decreased grazing frequency, only 35 per cent of the lucerne survived in the treatment with the slowest rotation.

Effects of grazing management on Sirosa phalaris herbage mass and persistence in a predominantly summer rainfall environment

2000 ◽  
Vol 40 (2) ◽  
pp. 155 ◽  
Author(s):  
G. M. Lodge ◽  
B. A. Orchard
Keyword(s):  
New South ◽  
Summer Rainfall ◽  
Grazing Management ◽  
Critical Periods ◽  
North West ◽  
The North ◽  
South Wales ◽  
Continuous Grazing ◽  
Plant Frequency ◽  
On Farm

Herbage mass, plant frequency and basal cover data collected from September 1993 to August 1996 were used to compare the effects of various seasonal closures with continuous grazing on the persistence of Sirosa phalaris (Phalaris aquatica cv. Sirosa) at 3 sites on the North West Slopes of New South Wales. Sites were on-farm and consisted of up to 10 treatments with 2 replicates and treatments were initially imposed in 2 different years. Pastures were either newly sown (3 years old) and grazed by either sheep or cattle, or degraded (14 years old) and grazed by sheep. Drought conditions prevailed in 1994–95, confounding the interpretation of the importance of treatments that involved long periods of closure, since significant effects could be attributed to both grazing exclusion and the timing of the closure in relation to plant phenology. However, across all sites and years, fitted values for phalaris herbage mass were generally significantly higher than the continuously grazed control in only 2 treatments: spring closure (at 1 site) and an extended spring closure combined with an autumn closure (at all sites). At the end of these studies phalaris herbage mass in spring–autumn closures was 4–32 times higher than the control plots. These results were confirmed by analysis of initial and final plant frequency data. At all sites, no recruitment of Sirosa seedlings occurred in any treatment. These data support the hypothesis that for increased persistence in a summer rainfall environment Sirosa phalaris requires some form of grazing management that involves the exclusion of grazing in the critical periods of spring and autumn.

The effects of grazing management systems on growth and nematode infections of beef cattle

1981 ◽  
Vol 32 (5) ◽  
pp. 825 ◽  
Author(s):  
MG Smeal ◽  
PJ Nicholls ◽  
GG Robinson ◽  
JK Bowler ◽  
RF Webb ◽  
...  
Keyword(s):  
Beef Cattle ◽  
Cattle Grazing ◽  
Early Summer ◽  
Grazing Management ◽  
Management Systems ◽  
Adult Cattle ◽  
South Wales ◽  
Pasture Contamination ◽  
Grazing Systems ◽  
Autumn And Winter

Different grazing management systems were used in autumn and winter on the Tablelands of New South Wales to reduce parasitic infectivity of pastures. The grazing systems were: pasture ungrazed; pasture grazed by undosed adult cattle, by frequently dosed calves, or by sheep. Pasture infectivity was assessed by worm counts made on parasite-free tracer calves during spring, and on permanently grazing steers during summer and the following autumn. Also, liveweight gains of young beef cattle which were dosed and moved to prepared pastures in late July were compared with those of cattle grazing on pastures which had been contaminated by undosed calves. All the grazing systems resulted in reduced levels of pasture contamination with worm eggs, and lower worm burdens of Ostevtagia ostevtagi and other nematodes during spring and early summer. The effects of grazing systems were reflected in greater liveweight responses compared with those of cattle grazing contaminated pasture. Grazing with sheep or adult cattle and using ungrazed pasture produced significant gains of up to 57 kg head-l during spring and summer. In some Tableland areas, continuous grazing of prepared pastures from July to December led to clinical parasitism in summer. The results suggest that pastures were freshly contaminated during spring which, in turn, resulted in a massive increase in O. ostevtagi burdens during summer.

Response of skeleton weed (Chondrilla juncea) to applied superphosphate and grazing management

1975 ◽  
Vol 15 (72) ◽  
pp. 102 ◽  
Author(s):  
GD Kohn ◽  
EG Cuthbertson
Keyword(s):  
New South ◽  
Trifolium Subterraneum ◽  
Wagga Wagga ◽  
Stocking Rate ◽  
Lolium Rigidum ◽  
Fertilizer Rate ◽  
South Wales ◽  
Continuous Grazing ◽  
Grazing Systems ◽  
Stocking Rates

The influence of pasture topdressing with superphosphate and of stocking rate on the Chondrilla uncea population in a clover-ryegrass (Trifolium subterraneum-Lolium rigidum) pasture was measured in a grazing experiment at Wagga Wagga, New South Wales, over the period 1962 to 1966. Superphosphate application reduced final weed populations at all stocking rates. Continuous grazing maintained skeleton weed populations at a low level, but increasing the stocking rate from 5 to 15 sheep ha-1 had little influence on weed numbers. A management comparison at a high stocking rate-high fertilizer rate showed that rotational grazing increased the weed population compared with continuous grazing systems.

Evaluation of oat forage for finishing prime lambs on the Northern Tablelands, New South Wales

1977 ◽  
Vol 17 (86) ◽  
pp. 385 ◽  
Author(s):  
KA Archer ◽  
FG Swain
Keyword(s):  
Dry Matter ◽  
New South ◽  
New South Wales ◽  
Early Spring ◽  
Grazing Management ◽  
South Wales ◽  
Grazing Systems ◽  
Grazing Period ◽  
Carry Over ◽  
Stocking Rates

In 1967 at Armidale, New South Wales, oats (Avena sativa cv. Cooba) were grown with or without 180 kg N ha-I and rotationally grazed on a three paddock system from July 13 to November 16 with Border Leicester x Merino lambs. Stocking rates were 20,40 or 60 sheep ha-1 (experiment 1). In 1968 (experiment 2) oats were rotationally grazed on either a three or four paddock system at stocking rates of 20, 30 or 40 lambs ha-1. Grazing began on either June 6 or July 17 and terminated on November 20. The rotational grazing systems allowed for a grazing period of two weeks and regrowth periods of four or six weeks. Application of nitrogen increased the quantity of dry matter available prior to grazing in 1967 by 20 per cent but did not affect regrowth rates during winter and early spring. In 1968, approximately 33 per cent more forage was available prior to grazing in mid-July than in early June. There was little effect of grazing management on the rate of regrowth. In both years, regrowth rates were low during winter and carry over residue was required to provide a continuity of available forage. Liveweight gains of lambs during winter and early spring reached 170 to 200 g head-1 day-1 at stocking rates of 20 or 30 sheep ha-1 for the early and late commencement of grazing treatments respectively. Lower gains to 120 g head-1 day-1 were recorded for six to eight weeks at higher stocking rates but subsequent liveweight losses occurred; these being greater if grazing commenced early. Neither N nor grazing management system materially affected liveweight gains. Approximately 1.5 kg available dry matter head-1day-1 was required at the start of each fortnightly grazing period to ensure maximum liveweight gains

Soil-extractable sulfur and pasture response to applied sulfur

1998 ◽  
Vol 38 (6) ◽  
pp. 567 ◽  
Author(s):  
G. C. Anderson ◽  
R. D. B. Lefroy ◽  
G. J. Blair
Keyword(s):  
Dry Matter ◽  
New South ◽  
Growth Period ◽  
Acid Digestion ◽  
Extraction Techniques ◽  
Organic S ◽  
South Wales ◽  
Trifolium Repens L ◽  
Soil Sulfur ◽  
The Relationship

Summary. A glasshouse experiment was conducted to study the correlation between various soil sulfur (S) extractants and pasture response to applied S grown under controlled environmental conditions (glasshouse) as influenced by variations in levels of extractable S. Intact paired soil cores were collected at 2-month intervals from an S x P factorial experiment at 4 field sites on the Northern Tablelands of New South Wales on 11 occasions. Soil samples were collected from each core and the cores placed in the glasshouse. Sulfur was applied to one core of each pair and basal nutrients applied to all cores which were then oversown with white clover (Trifolium repens L. cv. Haifa). The extractable S in the soil was analysed using the following techniques: 0.1 mol Ca(H2PO4)2/L (MCPt); 0.1 mol Ca(H2PO4)2/L, treated with activated charcoal (MCPi); water (H2O); 0.25 mol KCl/L, heated at 40°C for 3 h (KCl-40); 0.25 mol KCl/L, heated at 100°C for 4 h (KCl-100); 0.5 mol NaHCO3/L (NaHCO3); and an acid digestion of the soil (total). Dry matter yield and S content of the pasture shoots were measured for each 2-month growth period. The relationship between the various soil S extraction techniques and the response of pasture to applied S varied over time and was influenced by the level of inorganic S present in the soil and the amount of organic S extracted. When the level of MCPi-extractable S ranged between 2 and 22 µg S/g soil due to the application of fertiliser (summer 1987–88 and autumn 1988), or after a period of high mineralisation rates (spring 1988), the MCPi, MCPt, H2O and KCl-40 techniques had the highest correlation with the increase in S content of the pasture when S was applied. The higher correlation for the MCPt, H2O and KCl-40 techniques than the MCPi technique indicates that plants obtained some S from the organic S pool. In contrast, when the levels of MCPi-extractable S ranged between 2 and 10 µg S/g soil and the rate of mineralisation increased in response to an increase in soil temperature (June 1988 and June 1989) or moisture (September 1989) upon transfer of samples from the field to the glasshouse, the MCPt, H2O and KCl-40 techniques underestimated the available S pool and had lower r2 values than either the KCl-100 or NaHCO3 techniques.

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