Methane production by steers on pasture

1997 ◽  
Vol 77 (3) ◽  
pp. 519-524 ◽  
Author(s):  
W. P. McCaughey ◽  
K. Wittenberg ◽  
D. Corrigan
Keyword(s):  
Daily Intake ◽  
Sampling Period ◽  
Grazing Management ◽  
Sulphur Hexafluoride ◽  
Tracer Gas ◽  
Pasture Management ◽  
Gross Energy ◽  
Grazing Systems ◽  
Voluntary Intake ◽  
Stocking Rates

In order to determine the quantity of methane (CH4) produced by steers on pasture, 16 steers with a mean weight of 356 ± 25 kg were randomly selected from a larger group of cattle (n = 48) to evaluate the effects of grazing management and monensin controlled release capsule (CRC) administration on ruminal CH4 production using the sulphur hexafluoride (SF6) tracer-gas technique. Pasture management treatments consisted of two grazing systems (continuous stocking or 10-paddock rotational stocking) at each of two stocking rates (low, 1.1 steer ha−1 or high, 2.2 steers ha−1) with two replications of each pasture treatment. Half of the animals on each pasture treatment were administered a monensin CRC delivering 270 mg d−1, and untreated animals served as controls. During the 140-d grazing season, one steer from each treatment-replicate combination was sampled to determine daily intake and CH4 production on four occasions. The chemical composition of diets differed between grazing management treatments and sampling periods. Voluntary intake and CH4 production, adjusted for differences in body weight, were unaffected by grazing management, sampling period or by monensin CRC administration and averaged 0.69 ± 0.1 L kg BW−1 d−1 across all grazing management treatments. The energy lost through eructation of CH4 averaged 4.5 ± 1.4% of gross energy intake. Key words: Methane, cattle, environment, digestion efficiency, pasture, forage

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 COMMENTS ON THE GRAZING MANAGEMENT SESSION

1984 ◽  
pp. 207-208 ◽  
Author(s):  
K. Milligan
Keyword(s):  
Management System ◽  
Animal Production ◽  
Grazing Management ◽  
Critical Levels ◽  
Research Environment ◽  
Pasture Production ◽  
Hill Country ◽  
Grazing Systems ◽  
Stocking Rates ◽  
Better Than

This collection of papers does four significant things: 1. It concentrates on hill country. 2. Precisely defines the research environment in pasture levels and animal production terms. One can clearly see the consequences in animal production at different times of the year when pre-grazing and residual herbage levels are defined and varied and to see the effects of different grazing systems at these pasture levels. Much better than high vs low stocking rates. 3. Attempts to set pature targets as well as animal production targets. 4. Defines critical pasture DM levels both below which pasture production is reduced, and above which control is lost. The proximity to these critical levels will, for a farmer, more precisely define the grazing management system he should adopt and the levels of animal production he should be able to achieve

Mixed grazing systems of sheep and cattle to improve liveweight gain: a quantitative review

2013 ◽  
Vol 152 (4) ◽  
pp. 655-666 ◽  
Author(s):  
S. d'ALEXIS ◽  
D. SAUVANT ◽  
M. BOVAL
Keyword(s):  
Meta Analysis ◽  
Daily Weight Gain ◽  
Physiological Status ◽  
Average Daily Weight Gain ◽  
Pasture Management ◽  
Quantitative Review ◽  
Grazing Systems ◽  
Production Value ◽  
The Individual ◽  
Stocking Rates

SUMMARYMixed grazing is an alternative pasture management which can be used to increase ruminant performance and reduce gastro-intestinal nematodes. A meta-analysis was performed on the results of previous studies from the literature to quantify the benefit of mixed grazing with sheep and cattle and identify determinants and enhancing factors. The analysis focused on papers reporting measurements of average daily weight gain (ADG) of sheep and cattle, carried out simultaneously in mixed grazing and in mono-grazing. The meta-analysis used 179 observations from 16 experiments published in nine carefully selected papers. The benefits of mixed grazing were appraised using the individual ADG of sheep (ADGisheep), cattle (ADGicattle) and the overall performances (ADG per hectare (ADGha), g/day/ha). A theoretical production value (ADGha-Theo) was calculated from the ADGha in mixed and mono-grazing at similar stocking rates (SRs)/ha. The ADGisheepwas greater in mixed treatments compared with control treatments (+14·5 g/day,P<0·001) and varied with physiological status and SR (P<0·001). The ADGicattlewas similar in mixed and mono-grazing. At a global level ADGha in mixed treatments (ADGha-Mtrt) was higher by 28·6% compared with sheep alone and by 25·1% compared with cattle alone; also, ADGha-Mtrt was 8% higher than ADGha-Theo. The ADGha varied with physiological status and decreased with the proportion of sheep in association (P<0·01). The contribution of ADGha in mixed grazing due to each species was lower compared with gains for each species reared alone (1438v.2423 g/day/ha for sheep and 1687v.2491 g/day/ha for cattle,P<0·001).

Balancing animal, pasture and environmental outcomes in grazing management experiments

2017 ◽  
Vol 57 (9) ◽  
pp. 1775 ◽  
Author(s):  
D. L. Michalk ◽  
W. B. Badgery ◽  
D. R. Kemp
Keyword(s):  
Grassland Management ◽  
Environmental Benefits ◽  
Grazing Management ◽  
Stocking Rate ◽  
Commercial Practice ◽  
Large Plot ◽  
Grazing Systems ◽  
Landscape Variability ◽  
Native Pastures ◽  
Stocking Rates

About 60% of the gross value of Australia’s agriculture (AU$49 billion) is produced from the 85 million ha of temperate grasslands of southern Australia. A large part of this production comes from grazing livestock in the high-rainfall zone (HRZ) where 40% of the area has been retained as native and naturalised pastures, located in variable landscapes. These native pastures have seen a decline in productivity and increasing environmental problems, such as erosion, due to a loss of productive perennial species over recent decades. Grazing management systems have been advocated to not only balance the quality and quantity of forage with the nutritional demands of grazing animals, but also to manage the degradation caused by grazing. There has been an evolution of grazing management research through national projects from Temperate Pasture Sustainability Key Program to Sustainable Grazing Systems and then EverGraze, which has shifted from a focus on small plots and fixed stocking rates, to large-plot and farmlet experiments that include landscape variability and flexible grazing systems that more closely resemble commercial practice. These experiments generate reliable plant and animal response data that can be used to validate system models needed to assess the spatial and temporal challenges of grassland management. The present paper introduces the research conducted at the Orange proof site as part of the national EverGraze program. The research investigated the interactions between landscape variability and grazing method (1-, 4- and 20-paddock grazing management treatments) with flexible stocking rates. The following three key questions were addressed: (1) does increasing the number of paddocks and implementing rotational grazing result in a higher stocking rate, higher per hectare production and better economic outcomes; (2) which is the most appropriate combination of grazing method and stocking rate to achieve a higher and more stable perennial component to improve production and environmental benefits in different parts of the landscape; and (3) can landscape variability be identified, mapped and effectively managed on HRZ native grassland properties? This special edition of Animal Production Science answers these questions and provides recommendations for managing HRZ native pastures.

Post-experimental modelling of grazing systems to improve profit and environmental outcomes using AusFarm

2017 ◽  
Vol 57 (9) ◽  
pp. 1849 ◽  
Author(s):  
K. M. Broadfoot ◽  
W. B. Badgery ◽  
G. D. Millar
Keyword(s):  
Management Strategies ◽  
Grazing Management ◽  
Management Systems ◽  
Stocking Rate ◽  
Management Options ◽  
Experimental Modelling ◽  
Grazing Systems ◽  
Sheep Production ◽  
Flexible Management ◽  
Stocking Rates

Assessments of grazing systems are often constrained by the decisions regarding the management of the grazing systems, including stocking rate, and also the seasonal conditions that occur during the assessment period. These constraints have led to sometimes conflicting results about comparisons of grazing management systems. This paper examines 1-, 4- and 20-paddock (1P, 4P and 20P) grazing management systems to determine how the intensity of grazing management on native pastures influences the financial performance of sheep production systems. The performance of the grazing systems, as part of the Orange EverGraze research experiment, was initially examined using the biophysical data over the 4 years of the experiment and then a more detailed analysis over a longer timeframe was undertaken using the AusFarm simulation modelling software. Flexible management strategies to optimise ewe numbers, sale time of lambs, and adjust ewe numbers based on season, were also assessed to determine which management systems are the most profitable and sustainable. There was higher profit for the 20P grazing system than the 1P system during the experiment. However, when stocking rates were held constant at optimum levels and systems were simulated over 40 years, there was no difference between grazing systems. Modelling strategies used to vary stocking rates showed that flexible management options are better based on optimising ewe numbers and the sale time of lambs rather than changing ewe numbers between years. The sustainability of modelled systems was also assessed using frequency of events where the average herbage mass (0.8 t DM/ha) or ground cover (80%) in autumn dropped below levels that are associated with degradation. Degradation events occurred more so with increasing ewe number than lamb sale time. Overall, the most sustainable systems, when considering profitability and environmental issues, had a stocking rate of 4.2 ewes per ha, with lambs sold in February (2 or 18). Higher stocking rates (5.3 ewes/ha) would need to be run for more intensive grazing management to have higher profitability.

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

Grazing management.

2021 ◽  
pp. 184-204
Author(s):  
Gordon McL. Dryden
Keyword(s):  
Quality Assessment ◽  
Nutritive Value ◽  
Grazing Management ◽  
Utilization Rate ◽  
C4 Grasses ◽  
Grazing Systems ◽  
C3 And C4 Grasses ◽  
Stocking Rates ◽  
Pasture Yield

Abstract This chapter focuses on grazing management. Topics discussed include: (i) C3 and C4 grasses; (ii) the nutritive value of pastures; (iii) grazing systems; (iv) pasture yield, growth and quality assessment; (v) pasture utilization rate; (vi) calculation of carrying capacities and stocking rates; (vii) pasture budgeting; and (viii) feed-year plans.

The effect of different proportions of dried grass and concentrates in the diet on voluntary intake and performance of calves

1974 ◽  
Vol 18 (1) ◽  
pp. 49-58 ◽  
Author(s):  
T. A. McCullough
Keyword(s):  
Dry Matter ◽  
Daily Intake ◽  
Nitrogen Retention ◽  
Live Weight ◽  
Conversion Ratio ◽  
Metabolizable Energy ◽  
Weight Range ◽  
Gross Energy ◽  
Voluntary Intake ◽  
And Performance

SUMMARYComplete diets each containing (1) 0%, (2) 20%, (3) 40%, (4) 60% high-quality, (5) 20% and (6) 40% low-quality dried grass were given ad libitum to 48 British Friesian calves.The performance of the animals was studied over the stages of growth from 50 to 100 kg and 150 to 200 kg live weight. At each stage of growth the live-weight gain was similar on all treatments while the daily intake of dry matter was significantly affected by the treatments. Over the stage of growth from 50 to 100 kg live weight the intake of metabolizable energy was greatest on treatment 2 and lowest on treatment 4. The conversion ratio of metabolizable energy decreased with increasing levels and with both qualities of dried grass over the weight range 50 to 100 kg.When the calves reached 100 kg live weight, digestibility and N balance studies were carried out. The metabolizable energy (ME) expressed as a percentage of the gross energy decreased with increasing levels and with the lower quality of dried grass. Nitrogen retention was not significantly affected by treatment differences.The relationships of the voluntary intake of dry matter, ME intake and the conversion ratio of ME with the ME expressed as a percentage of gross energy over the lower live-weight range are also presented.

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