The nutrition of ruminants grazing native and improved pastures. IV.* Long-term effects of the quantity of superphosphate applied on the nutritive value of the diet selected by sheep grazing a pasture originally sown to Phalaris aquatica and Trifolium repens

1979 ◽  
Vol 30 (3) ◽  
pp. 565 ◽  
Author(s):  
JP Langlands ◽  
JE Bowles ◽  
GE Donald
Keyword(s):  
Nitrogen Content ◽  
Trifolium Repens ◽  
Nutritive Value ◽  
Sheep Grazing ◽  
Long Term Effects ◽  
Phalaris Aquatica ◽  
Grazing Sheep

Small plots sown to Phalaris aquatica–Trifolium repens in 1967 were fertilized with either 0, 188 or 375 kg superphosphate ha-1 year-1 from 1967 to 1976; the plots were grazed uniformly between 1967 and 1975 and at three stocking intensities during 1975 and 1976. The composition of the forage on offer and of the diet selected by grazing sheep were measured at 2-monthly intervals during 1976. Phalaris largely died out from plots which did not receive superphosphate. Available forage, and its content of clover, nitrogen and most minerals were substantially greater on plots that received fertilizer, as were the digestibility and nitrogen content of the diet selected. The nutritive value of the diet selected was greatest on plots which received 375 kg superphosphate ha-1 year-1. The nitrogen content of the diet selected generally increased with increasing stocking intensity, but this trend was not evident for digestibility; interactions between the quantity of fertilizer applied and stocking intensity were not significant. Digestibility and nitrogen content of the diet varied between months, with the quantity of green forage and clover on offer, and with the nitrogen content of the available forage. __________________ *Part III, Aust. J. Agric. Res., 29, 1301 (1978).

Studies on the nutritive value of the diet selected by grazing sheep IV. Variation in the diet selected by sheep differing in age, breed, sex, strain and previous history

1969 ◽  
Vol 11 (3) ◽  
pp. 369-378 ◽  
Author(s):  
J. P. Langlands
Keyword(s):  
Nitrogen Content ◽  
Nutritive Value ◽  
Previous History ◽  
In Vitro Digestibility ◽  
Sheep Grazing ◽  
Faecal Nitrogen ◽  
Grazing Sheep ◽  
Grazing History

SUMMARYThe ability of two groups of six Merino wethers aged 6 and 66 months to digest a lucerne ration was examined in order to detect possible biases in the use of faecal nitrogen as a faecal index substance. Earlier work with this technique had indicated a difference in selectivity between young and older sheep. No difference in ability to digest the ration was observed and it was concluded that the earlier observation was not an artefact in the faecal nitrogen technique. Oesophageal fistulae were prepared in 120 sheep differing in breed, sex, age, strain and previous history. Determinations were made of the nitrogen content, and in one experiment of the in vitro digestibility of the diet selected by sheep grazing various pastures. Significant differences in the nitrogen content of the diet selected by sheep varying in breed, age and previous grazing history were recorded on some pastures on some occasions but not on others. No significant differences were observed between sheep varying in strain or sex. No reason could be suggested for the occasional differences between groups in the nitrogen content or digestibility of the diet selected, but it appeared unlikely that it would be a major source of variation in the productivity of the different groups at pasture.

Studies on the nutritive value of the diet selected by grazing sheep V. Further studies of the relationship between digestibility estimated in vitro from oesophageal fistula samples and from faecal and dietary composition

1969 ◽  
Vol 11 (3) ◽  
pp. 379-387 ◽  
Author(s):  
J. P. Langlands
Keyword(s):  
Nitrogen Content ◽  
Nutritive Value ◽  
Live Weight ◽  
Faecal Output ◽  
Faecal Nitrogen ◽  
Grazing Sheep ◽  
Predicted Values ◽  
Stocking Rates ◽  
The Relationship

SUMMARYDigestibility was estimated in vitro from a total of 167 oesophageal fistula samples collected over a period of 16 to 24 months from adult sheep grazing eight Phalaris tuberosa-Trifolium repens pastures stocked continuously at rates of from 2·5 to 37·1 sheep per ha. Corresponding estimates of the nitrogen content of the faeces and of the fistula samples, the live weight and faecal output of the sheep, and of the herbage availability of the pasture were obtained.The observations were stratified on the bases of stocking rate, digestibility, month of the year, herbage availability or organicmatter intake. Relationships between digestibility estimated by the fistula technique and faecal nitrogen content (model B) and between digestibility and faecal nitrogen content, nitrogen content of the dietary dry and organic matter, and faecal output per unit live weight (model A) were calculated for each stratum.There were significant differences between relationships derived for the various stocking rates, levels of digestibility, times of year, levels of intake and levels of herbage availability; predicted values of digestibility for given values of the independent variables differed by as much as 20 units of digestibility. Model A was substantially more precise than model B.Differences between estimates of digestibility, derived by the fistula technique and by a general faecal nitrogen—digestibility relationship, established by Lambourne and Reardon (1963a) were calculated. The differences were related to digestibility and to herbage availability.The implications of these results are discussed and it is concluded that faecal nitrogen content is not a satisfactory index of the digestibility of the diet selected by grazing sheep.

Long-term effects of sheep grazing on giant hogweed (Heracleum mantegazzianum)

Hydrobiologia ◽  
1996 ◽  
Vol 340 (1-3) ◽  
pp. 277-284 ◽  
Author(s):  
Ulla Vogt Andersen ◽  
Birgitte Calov
Keyword(s):  
Sheep Grazing ◽  
Long Term Effects ◽  
Heracleum Mantegazzianum

scholarly journals Long-term effects of rotational prescribed burning and low-intensity sheep grazing on blanket-bog plant communities

2013 ◽  
Vol 50 (3) ◽  
pp. 625-635 ◽  
Author(s):  
Hyohyemi Lee ◽  
Josu G. Alday ◽  
Rob J. Rose ◽  
John O'Reilly ◽  
Rob H. Marrs
Keyword(s):  
Plant Communities ◽  
Prescribed Burning ◽  
Sheep Grazing ◽  
Long Term Effects ◽  
Low Intensity ◽  
Blanket Bog

Estimation of the Density of Feral Goats in Part of Arid South Australia by means of the Peterson Estimate

1984 ◽  
Vol 11 (1) ◽  
pp. 93 ◽  
Author(s):  
RP Henzell ◽  
PI McCloud
Keyword(s):  
South Australia ◽  
Grazing Pressure ◽  
Sheep Grazing ◽  
Long Term Effects ◽  
Arid Rangeland

The density of feral goats in about 234 km2 of arid rangeland used for sheep grazing in South Australia was estimated by means of a mark-resight technique. Marking and subsequent resighting were done at watering points. The Petersen estimate was 4.4 goats per square kilometre; adjustment to allow for nonrandom behaviour raised this estimate to 5.0 km-1. Maximum allowable sheep density is 12 km-2. The goat density we observed imposes an added burden on the vegetation. The densities of red and western grey kangaroos, when added together, approximate that of the goats. Rabbits are virtually absent. The long-term effects of the total grazing pressure on the vegetation cannot be predicted in detail but will probably be deleterious.

scholarly journals Long-Term Effects of Sheep Grazing in Various Densities on Marsh Properties and Vegetation Dynamics in Two Different Salt-Marsh Zones

2019 ◽  
Vol 43 (2) ◽  
pp. 298-315 ◽  
Author(s):  
J. P. Bakker ◽  
M. Schrama ◽  
P. Esselink ◽  
P. Daniels ◽  
N. Bhola ◽  
...  
Keyword(s):  
Salt Marsh ◽  
Vegetation Dynamics ◽  
Sheep Grazing ◽  
Long Term Effects
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