Limitations to animal production imposed by seasonal fluctuations in pasture and by management procedures

1959 ◽  
Vol 10 (2) ◽  
pp. 248 ◽  
Author(s):  
WM Willoughby
Keyword(s):  
Grazing Pressure ◽  
Animal Production ◽  
Seasonal Fluctuations ◽  
Wool Production ◽  
Continuous Grazing ◽  
Management Procedures ◽  
Grazing Systems ◽  
The Individual ◽  
Stocking Rates

An experiment with Merino wethers on a Phalaris tuberosa-subterraneum clover-volunteer grass pasture has compared throughout an annual cycle the effects of: (a) Seasonal fluctuations in quantity and quality of pasture on liveweight gains and wool production in sheep. (b) Different grazing systems at equal stocking rates both on pasture growth and on liveweight and wool production in sheep. (a) Availability of dry pasture did not affect animal production so long as green pasture was present. Small increases in green pasture in the period of slow growth (winter) gave large increases in liveweight and wool production. Large increases in green pasture in the period of rapid growth (spring) had no effect on the animal. On dry pasture (summer) heavy sheep lost more weight than light sheep. Increasing the amount of dry pasture reduced liveweight loss only slightly but resulted in a greater rate of breakdown of plant material. An asymptotic relationship between availability of green pasture aid animal gain is presented, the asymptote in this instance occurring at a,pproxirnatnly 1400 lb dry matter per acre. The implications of the results are discussed with reference to methods of investigation of species, fertilizers, end management procedures aimed at 01-ercoming pasture limitations to animal production. The validity of investigations which do not take into account the relative constancy of grazing pressure throughout the year, and the continuing effects of plant on animal and animal on plant, is questioned. (b) Regardless of the degree to which pastures had been checked by grazing in spring, all dried out simultaneously on the onset of summer, and all sheep on all treatments reached their peak liveweight turning point on approximately the same date. Less than one-third of the liveweight gain potential of the pasture was attained on any one of the three grazing systems. The mean amounts of the individual pasture components, and of the total weight of pasture, were identical at any one time under the three grazing systems. The closer the systems approached towards continuous grazing the greater were the liveweight gains and wool production.

scholarly journals Using Artificial Neural Networks for Equalizing Time Series Considering Seasonal Fluctuations

2019 ◽  
Vol 71 ◽  
pp. 01003
Author(s):  
J. Vrbka ◽  
J. Horák ◽  
V. Machová
Keyword(s):  
Neural Networks ◽  
Time Series ◽  
Artificial Neural Networks ◽  
Seasonal Fluctuations ◽  
Republic Of China ◽  
The People ◽  
Data Points ◽  
Artificial Neural ◽  
The Individual

The objective of this contribution is to prepare a methodology of using artificial neural networks for equalizing time series when considering seasonal fluctuations on the example of the Czech Republic import from the People´s Republic of China. If we focus on the relation of neural networks and time series, it is possible to state that both the purpose of time series themselves and the nature of all the data are what matters. The purpose of neural networks is to record the process of time series and to forecast individual data points in the best possible way. From the discussion part it follows that adding other variables significantly improves the quality of the equalized time series. Not only the performance of the networks is very high, but the individual MLP networks are also able to capture the seasonal fluctuations in the development of the monitored variable, which is the CR import from the PRC.

The performance of young sheep grazing pastures sown to combinations of lucerne or subterranean clover with ryegrass or phalaris

1972 ◽  
Vol 12 (56) ◽  
pp. 240 ◽  
Author(s):  
KFM Reed ◽  
RW Snaydon ◽  
A Axelsen
Keyword(s):  
Subterranean Clover ◽  
Animal Production ◽  
Grass Species ◽  
Legume Species ◽  
Sheep Grazing ◽  
Wool Production ◽  
High Production ◽  
Supplementary Feed ◽  
Stocking Rates ◽  
Clover Pasture

Young sheep were rotationally grazed, at two stocking rates, on pasture sown to combinations of two legume species (lucerne or subterranean clover) and two grass species (a mixture of annual and biennial ryegrass or phalaris) at Canberra. Liveweight gains were 45 per cent greater, and wool production was 10 per cent greater, on the lucerne dominant pasture (87 per cent lucerne) than on the grass dominant subterranean clover pasture (8 per cent subterranean clover). The differences were maximum during summer, but also occurred during spring. Mortality and supplementary feed requirement on grass dominant pasture was double that on lucerne pasture. Liveweight gains were 13 per cent greater on pasture sown to ryegrass than on pasture sown to phalaris. Sheep mortality was eight times greater on the phalaris than on the ryegrass pasture, and survival feed requirements at least double. The superior animal production from lucerne pasture was due mainly to the ability of lucerne to grow during periods of low rainfall and to maintain a high production of legume in the pasture.

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.

An evaluation of cereal stubbles for sheep production

1976 ◽  
Vol 27 (6) ◽  
pp. 881 ◽  
Author(s):  
JG Mulholland ◽  
JB Coombe ◽  
M Freer ◽  
WR McManus
Keyword(s):  
Plant Material ◽  
Green Plant ◽  
Animal Production ◽  
Stocking Rate ◽  
Mineral Supplement ◽  
Wool Production ◽  
Sheep Production ◽  
One Year ◽  
Cereal Residues ◽  
Stocking Rates

The production of young crossbred wethers grazing oat, barley and wheat stubbles was measured in each of three years at stocking rates ranging from 15 to 30/ha. In one year, production on 'weedy' stubbles was compared with that of 'clean' (weed-free) stubbles, and also the effect of a wheat–urea–mineral supplement on the production of sheep was measured on oat stubble. Liveweight change and wool production were significantly influenced by the availability of green plant material and by stocking rate, but not by supplementation. The maximum liveweight loss in any year was 7.5 kg and the maximum gain 6.0 kg, both recorded over 11 weeks' grazing. Mean daily clean wool production was 9.9 g/sheep at the lower stocking rate and 6.6 g/sheep at the higher rate, but production per hectare was 10–60% higher at the heavier stocking rate. The ranking of the crop stubbles with respect to animal production was not consistent from year to year. Intense selection for green plant material by sheep resulted in the proportion of green in the diet being nearly always greater than 80%, when the weight of this material on the plots was more than 40 kg dry matter/ha. It appeared that a low intake of nitrogen was not the main limitation to animal production. A maximum of only 36% of the crop residue which disappeared during the experiment could be accounted for as animal intake. Thus it is unlikely that the potential of cereal residues as a source of food for animal production will be realized with grazing sheep.

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

Sustainable sheep management using continuous grazing and variable stocking rates in Patagonia: a case study

2012 ◽  
Vol 34 (3) ◽  
pp. 285 ◽  
Author(s):  
Gabriel Oliva ◽  
Daniela Ferrante ◽  
Silvina Puig ◽  
Marcos Williams
Keyword(s):  
Adaptive Management ◽  
Coefficient Of Variation ◽  
Management Tool ◽  
Annual Rainfall ◽  
Wool Production ◽  
Continuous Grazing ◽  
Key Species ◽  
Southern Patagonia ◽  
Sheep Production ◽  
Stocking Rates

Adaptive rangeland management based on continuous grazing by sheep was implemented at Los Pozos station, on the Magellan tussock steppes of southern Patagonia, between 1990 and 2010. The numbers of sheep were adjusted annually following a stocking strategy tracking the herbage mass. Herbage mass was assessed by harvesting short grass species at peak herbage mass and grazing capacity was estimated based on sheep requirements. Historic production records under a traditional continuous grazing management (1930–89) were contrasted with those of the adaptive management period (1990–2010). Stocking rates of 0.59 sheep ha–1 year–1 in the period from 1930 to 1989 dropped to 0.35 sheep ha–1 year–1 in the adaptive management period. Mean herbage mass of short grasses during this latter period was 194 ± 12 kg DM ha–1 and the stubble height of the key species, Poa spiciformis, was 24 ± 0.7 mm. Lamb marking rates and extraction rates increased from 72 to 87%, and from 28 to 48%, respectively, under adaptive management when compared with historic management, and historic levels of sheep sales were maintained: 4405 v. 4602 animals year–1. Wool production fell from 36 102 to 26 771 kg year–1. Annual sheep production under adaptive management was less variable, as the annual coefficient of variation fell by 41% for lambing rates, by 25.8% for wool production, and by 40% for sheep extraction rates, compared with historic records, even though the inter-annual rainfall coefficient of variation increased by 25% over the same period. It is concluded that, under adaptive management, herbage production, stubble height and sheep production remained stable over 20 years. The adaptive strategy allowed a stabilisation of production and is a potentially valuable management tool in view of the expected increase in variability of rainfall predicted by global climate models for Patagonia and other rangeland areas.

An evaluation of the production potential of six tropical grasses under grazing. 3. Responses to set stocking rates under continuous grazing

1992 ◽  
Vol 32 (6) ◽  
pp. 693 ◽  
Author(s):  
TR Evans ◽  
JB Hacker
Keyword(s):  
Animal Production ◽  
Stocking Rate ◽  
Production Potential ◽  
Species Response ◽  
Highest Weight ◽  
Continuous Grazing ◽  
Average Rainfall ◽  
Kikuyu Grass ◽  
Stocking Rates ◽  
Grazing Pressures

The response of 3 setaria cultivars, the setaria variety splendida, kikuyu grass, and pangola grass to stocking rates of 4-6 steers/ha under continuous grazing was evaluated over a 3-year period. On a year-round basis, averaged over stocking rates, liveweight gain per ha ranged from 822 kg on Narok (164 kg/steer) to 568 kg on Kazungula (114 kg/steer). Narok produced the highest weight gains in summer and winter (142 and 23 kg/steer, respectively). The greatest winter weight loss was from steers grazing Nandi and Kazungula (both -15 kg/steer). Animal production in a year of above-average rainfall, in both summer and winter periods, was markedly reduced overall, even though the quantity of feed on offer was increased. The year x grass interaction was statistically significant in summer, but year x stocking rate and grass x stocking rate were not. Species response to stocking rate showed a linear relationship between stocking rate and liveweight gain per steer, declining with increasing stocking rate, except for Narok setaria where the reverse occurred over the range of 4-6 steers/ha. The results of this experiment support those previously published on these 6 grasses and demonstrate the species potential for good levels of animal production per ha and their ability to withstand high grazing pressures and to maintain weed-free pastures.

Evaluation of natural annual pastures at Trangie in central western New South Wales. 1. Sheep production

1973 ◽  
Vol 13 (62) ◽  
pp. 238
Author(s):  
RJ Campbell ◽  
DG Saville ◽  
GE Robards
Keyword(s):  
New South ◽  
Management Strategies ◽  
New South Wales ◽  
Grazing Pressure ◽  
Stocking Rate ◽  
Wool Production ◽  
South Wales ◽  
Sheep Production ◽  
Stocking Rates ◽  
Sheep Wool

Natural annual pasture at Trangie, New South Wales, was set stocked from August, 1967 to December 1970 at rates of 2.5, 3.7, and 4.9 merino wethers per ha to determine an optimum stocking rate for the pasture type. All stocking rates were supported without the necessity to hand feed any sheep. Wool production per head was reduced significantly by increased stocking rate in 1968, but not in 1969 and 1970. The suppression of barley grass at the higher stocking rates appeared to benefit animal production in 1969. Substitution of portion of the natural annual pasture with areas of lucerne or natural perennial pasture was also investigated and found to be ineffective in increasing wool production per head above that of wethers at similar rates of stocking on natural annual pasture alone. Possible reasons for the apparent failure of the grazing supplements, particularly lucerne, are discussed in terms of grazing pressure and management strategies.

Studies on the Mitchell Grass Association in South-Western Queensland. 3. Pasture and Wool Production Under Different Rates of Stocking and Continuous or Rotational Grazing.

1993 ◽  
Vol 15 (2) ◽  
pp. 302 ◽  
Author(s):  
R Roe ◽  
GH Allen
Keyword(s):  
Supplementary Feeding ◽  
Major Influence ◽  
Stocking Rate ◽  
Rotational Grazing ◽  
Management Planning ◽  
Wool Production ◽  
Continuous Grazing ◽  
Winter Grazing ◽  
Grazing Period ◽  
Stocking Rates

Pasture productivity and wool production on the Warrego Mitchell grass (Astrebla spp.) rangeland in south-westem Queensland were studied over a period of 13 years under continuous or rotational grazing, each at three stocking rates. The stocking rates were one sheep to three, two or one hectares and the rotational grazing was a six- monthly system of summer or winter grazing. The grazing treatments were applied over two five- year terms with a nil-grazing period at the conclusion of each. The latter periods provided a means of measuring the cumulative effects of the grazing treatments. Drought conditions prevailed during the first term so that supplementary feeding was necessary, but the second experienced above average rainfall. Quarterly measurements were made of the pasture dry matter on offer and its botanical and chemical composition. Monthly sheep liveweights, annual wool production and sheep size development in each term were also measured and monetary returns from wool calculated. Rainfall had a major influence on the results recorded and tended to nullify the effects of grazing treatments. Its unpredictability precludes the reliable use of complex techniques in management planning. The overall results suggested that the optimum grazing management of this Mitchell grass rangeland would be continuous grazing at a stocking rate of one sheep to two hectares. Supplementary feeding during drought would be obligatory and should be budgeted for in long-term planning. There was a 50% higher monetary return from this grazing treatment than from the lighter stocking rate and pasture stability (maintenance of Astrebla spp.) was sustained. Pasture stability was adversely affected by the heavier stocking rate. There was no srlstained advantage from rotational grazing compared with continuous grazing.

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).

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