Diet selected by lambs and yearling sheep grazing on annual and perennial pastures in Southern Victoria

1967 ◽  
Vol 7 (25) ◽  
pp. 141 ◽  
Author(s):  
RW Hodge ◽  
JJ Doyle
Keyword(s):  
Nitrogen Content ◽  
Consistent Difference ◽  
Botanical Composition ◽  
Sheep Grazing ◽  
The Mean ◽  
Species Being ◽  
Clover Content

There was no consistent difference in the botanical composition or nitrogen content of the diet selected by lambs and yearling sheep grazing annual or perennial pastures in the spring. On the annual pasture, where the grass and clover content was similar, selection by the animals appeared to be random with no particular species being favoured. On the perennial pasture, where the clover content remained below 20 per cent, the mean percentage of clover in the diet selected by the lambs increased from less than 5 per cent when they were seven weeks old to over 50 per cent at 16 weeks of age. Over the same period, the mean percentage of clover in the diet selected by the yearlings increased from less than 10 per cent to over 40 per cent.

scholarly journals Effects of the MaxP (TM) endophyte in tall fescue on pasture production and composition, and the sheep grazing preference in a dryland environment

2007 ◽  
Vol 13 ◽  
pp. 259-262
Author(s):  
K.N. Tozer ◽  
S. Ates ◽  
N.R. Mapp ◽  
M.C. Smith ◽  
R.J. Lucas ◽  
...  
Keyword(s):  
New Zealand ◽  
Tall Fescue ◽  
Dry Matter ◽  
Early Spring ◽  
Botanical Composition ◽  
Sheep Grazing ◽  
Pasture Production ◽  
Basal Diameter ◽  
Matter Production ◽  
Annual Grasses

Pasture growth, botanical composition and sheep grazing preference were measured over 20 months in tall fescue (cultivar Advance), without endophyte (Nil) or infected with AR542 (MaxPTM) endophyte, and clover pastures sown into a dryland soil, Canterbury, New Zealand. Pastures were rotationally grazed with sheep, with grazing preference for the two endophyte treatments measured in late autumn and early spring. Annual dry matter production from April 2004 to April 2005 was not significantly different between AR542 (6293 kg DM/ha) and Nil (5864 kg DM/ha) tall fescue. The number of tall fescue plants/m2 and their basal diameter was greater for AR542 (35 plants/m2, 7.5 cm diameter) than Nil endophyte tall fescue (28 plants/m2, 6.8 cm diameter). AR542 endophyte tall fescue pastures had fewer weeds, mainly annual grasses, than Nil endophyte pastures throughout the trial. Grazing preference, measured by the number of sheep grazing each plot, and decline in pasture height did not differ between Nil and AR542 tall fescue. Keywords: tall fescue, novel endophyte, AR542, botanical composition, weed, grazing preference

Effects of time and rate of paraquat application on yield and botanical composition of annual pastures containing subterranean clover in a Mediterranean climate

1973 ◽  
Vol 13 (64) ◽  
pp. 556
Author(s):  
DW Barrett ◽  
GW Arnold ◽  
NA Campbell
Keyword(s):  
Dry Matter ◽  
Mediterranean Climate ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Botanical Composition ◽  
Minimum Loss ◽  
Major Species ◽  
Nitrogen Phosphorus ◽  
Clover Content ◽  
Made In

Pastures containing subterranean clover (Trifolium subterraneum) and either Vulpia spp. or Bromus rigidus as the other major species were sprayed at 0, 0.07, 0.14 and 0.21 kg a.i. ha-1 of paraquat ion between June and early October in Western Australia. Spraying removed the grasses and produced pastures containing up to 95 per cent clover. Mid-winter applications were more effective in increasing clover content than those made in spring. These changes in botanical composition were evident in the year following spraying, but were less marked. Yields of dry matter were reduced by paraquat, especially 'in the period immediately following spraying. These losses tended to decline as the growing season progressed, but at the close they were still evident on the Bromus rigidus pasture sprayed in July. Yields at the end of the subsequent season were similar on all treatments. Paraquat applied in mid-August at 0.14 kg a.i. ha-1 to both pastures produced the greatest change in botanical composition with the minimum loss of yield. The concentrations of nitrogen, phosphorus, calcium and magnesium were higher in mature herbage on paraquat treatments. Total yields of nutrients were similar between treatments because of reduced dry matter yield.

scholarly journals Age, growth and yield per recruit analysis of the pintado Pseudoplatystoma corruscans (Agassiz, 1829) in the Cuiabá River basin, Pantanal Matogrossense, Brazil

2004 ◽  
Vol 64 (2) ◽  
pp. 257-264 ◽  
Author(s):  
L. A. F. Mateus ◽  
M. Petrere Jr.
Keyword(s):  
Standard Length ◽  
Total Mortality ◽  
Age And Growth ◽  
Growth And Yield ◽  
Dry Period ◽  
Growth Rings ◽  
Pectoral Fins ◽  
The Mean ◽  
Yield Per Recruit ◽  
Species Being

The age and growth of the pintado Pseudoplatystoma corruscans were studied during the period from May 1994 to May 1995. The standard length ranged from 52 to 145 cm and the weight from 1.3 to 41 kg. The biometric relationship between the standard length (Ls) and total length (Ltotal) and between the total weight (Wt) and the standard length (Ls) were obtained for the species, being respectively: Ltotal = 3.296 + 1.069 * Ls and Wt = 0.00624 * Ls3.134.The condition factor calculated monthly suggests the spawning season to be between the months of February and March. The age was estimated by counting growth rings present in the spines of the pectoral fins, and 10 age classes were detected. The mean distance of the last ring until the border of the spine suggests that the period of least growth is between July and September (dry period). Von Bertalaffy's equation describing the growth of the pintado is: Lt = 183 * [1 - exp - 0.085 * (t + 3.274)]. Total mortality was Z = 0.24 year-1 and natural mortality M = 0.20 year-1. As the present level of exploitation, F = Z - M = 0.04 year-1, we conclude that the pintado stock was still underexploited in the Pantanal in the sampled period.

Triticale out-performs wheat on range of UK soils with a similar nitrogen requirement

2016 ◽  
Vol 155 (2) ◽  
pp. 261-281 ◽  
Author(s):  
S. E. ROQUES ◽  
D. R. KINDRED ◽  
S. CLARKE
Keyword(s):  
Harvest Index ◽  
Field Experiments ◽  
N Uptake ◽  
N Fertilizer ◽  
Yield Response ◽  
Consistent Difference ◽  
Total N ◽  
The Mean ◽  
The Uk ◽  
N Rates

SUMMARYTriticale has a reputation for performing well on poor soils, under drought and with reduced inputs, but there has been little investigation of its performance on the better yielding soils dominated by wheat production. The present paper reports 16 field experiments comparing wheat and triticale yield responses to nitrogen (N) fertilizer on high-yielding soils in the UK in harvest years 2009–2014. Each experiment included at least two wheat and at least two triticale varieties, grown at five or six N fertilizer rates from 0 to at least 260 kg N/ha. Linear plus exponential curves were fitted to describe the yield response to N and to calculate economically optimal N rates. Normal type curves with depletion were used to describe protein responses to N. Whole crop samples from selected treatments were taken prior to harvest to measure crop biomass, harvest index, crop N content and yield components. At commercial N rates, mean triticale yield was higher than the mean wheat yield at 13 out of 16 sites; the mean yield advantage of triticale was 0·53 t/ha in the first cereal position and 1·26 t/ha in the second cereal position. Optimal N requirement varied with variety at ten of the 16 sites, but there was no consistent difference between the optimal N rates of wheat and triticale. Triticale grain had lower protein content and lower specific weight than wheat grain. Triticale typically showed higher biomass and straw yields, lower harvest index and higher total N uptake than wheat. Consequently, triticale had higher N uptake efficiency and higher N use efficiency. Based on this study, current N fertilizer recommendations for triticale in the UK are too low, as are national statistics and expectations of triticale yields. The implications of these findings for arable cropping and cereals markets in the UK and Northern Europe are discussed, and the changes which would need to occur to allow triticale to fulfil a role in achieving sustainable intensification are explored.

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.

Laboratory estimates of the nutritive value of some herbaceous native legumes

1981 ◽  
Vol 21 (113) ◽  
pp. 583 ◽  
Author(s):  
RDH Cohen ◽  
GPM Wilson
Keyword(s):  
Nitrogen Content ◽  
Dry Matter ◽  
Nutritive Value ◽  
Phosphorus Content ◽  
Dry Matter Yield ◽  
P Values ◽  
Calcium Magnesium ◽  
The Mean ◽  
Exotic Legumes ◽  
Soil Level

Forty-four accessions of herbaceous native legumes from the genera Glycine and Galactia were grown in a glasshouse in a soil-sand-nutrient mixture that contained adequate phosphorus, potassium, calcium, magnesium, sulfur and molybdenum for plant growth. They were grown as individual plants with four replications of each. All plants were cut to soil level on August 18; regrowth was cut on October 7, November 22 and December 30 (harvests 1,2 and 3). The herbage was dried and analysed for nitrogen (g N/kg OM), phosphorus (g P/kg OM) and organic matter digestibility (% OMD). There were significant differences between the accessions for values of dry matter yield (P<0.001), nitrogen content (P<0.01), phosphorus content (P<0.001) and OMD (P<0.05). The mean nitrogen content declined at each harvest (40.6,33.7 and 31.7 g N/kg OM, respectively; P<0.05) and OMD of the herbage at harvest 3 was less than that at 1 and 2 (70.4, 71.1 and 67.6%, respectively; P<0.05). Herbage from harvest 1 had significantly greater P values than that from harvests 2 and 3 (4.7,4.2 and 4.4 g P/kg OM; P< 0.05). Plant yield was correlated with both nitrogen yield (r = 0.98; P<0.001) and phosphorus yield (r = 0.93; P<0.01) but not with OMD. Nitrogen content and digestibility were correlated (r = 0.48; P<0.01) but neither attribute was significantly correlated with phosphorus content. Samples of native herbaceous legumes belonging to the genera Desmodium and Kennedia and of some exotic legumes were collected from a nursery and analysed for N, P and OMD. The N and P values of all these legumes were in the range 31.9-39.2 g N/kg OM and 3.0-4.1 g P/kg OM, and compared favourably with those of the legumes grown in the glasshouse. The OMD of the exotic legumes (range 61.3-85.2%) compared favourably with those of the native legumes grown in the glasshouse but the natives Desmodium spp. and Kennedia spp. (range 26.7-35.4%) were very much lower than the Glycine spp. and Galactia spp.

scholarly journals The distribution of heterozygosity in temperate and tropical species of Drosophila

1981 ◽  
Vol 38 (2) ◽  
pp. 137-156 ◽  
Author(s):  
B. D. H. Latter
Keyword(s):  
Breeding Population ◽  
Tropical Species ◽  
Average Intensity ◽  
Consistent Difference ◽  
Neutral Model ◽  
Relative Contribution ◽  
Group I ◽  
Significant Difference ◽  
Population Sizes ◽  
The Mean

SUMMARYElectrophoretic surveys for nine species of Drosophila have been summarized in terms of the relative contribution to heterozygosity of each of ten gene frequency classes, the mean frequency of heterozygotes within subpopulations, and the degree of genetic divergence between subpopulations. It has been shown that the neutral model proposed by Kimura, and modified by Ohta to include the accumulation of slightly disadvantageous mutations, is capable of explaining all features of the data. The consistent difference between group I and group II enzymes can be explained by a difference in the average intensity of selection against mutational variants in the two groups. A highly significant difference between the temperate and tropical species in the distribution of heterozygosity appears to be due to the smaller effective breeding population sizes in the case of the temperate species.

Ruminal degradation characteristics of some African rangeland grasses

1995 ◽  
Vol 125 (2) ◽  
pp. 189-197 ◽  
Author(s):  
P. J. O'Reagain ◽  
B. C. Goetsch ◽  
R. N. Owen-Smith
Keyword(s):  
Cell Wall ◽  
Dry Matter ◽  
Agricultural Development ◽  
Cynodon Dactylon ◽  
Themeda Triandra ◽  
Heteropogon Contortus ◽  
Degradation Rates ◽  
Ruminal Degradation ◽  
The Mean ◽  
Species Being

SUMMARYThe seasonal rate and extent of dry matter (DM) and neutral detergent fibre (NDF) degradation of the African sourveld grasses Alloteropsis semialata, Andropogon appendiculatus, Cynodon dactylon, Elionurus muticus, Eragrostis plana, Harpochloa falx, Heteropogon contortus, Hyparrhenia hirta, Microchloa caffra, Themeda triandra and Tristachya leucothrix in the rumen were measured using the nylon bag technique at the Döhne Agricultural Development Institute, South Africa, in 1993. The size of the soluble fraction (SF) was markedly different (P < 0·05) between species, being largest in A. semialata (22·6%) and smallest in E. plana (13%). Over all species, the mean SF was highest (P < 0·01) in spring (21·6%) and lowest in winter (11·8%). Species differed (P < 0·05) in the size of the potentially digestible fraction (PDF), with H. contortus and T. leucothrix having the largest (71%) and M. caffra the smallest (53%) PDF. Mean PDF declined (P < 0·01) from spring (77·3%) through to winter (55·8 %). The rate of DM degradation (kd) in the rumen also differed (P < 0·01) between species, with C. dactylon and A. semialata having the fastest (0·054) and E. plana and A. appendiculatus the slowest (0·039) degradation rates. Mean kd values were lower (P < 0·05) in winter (0·039) than in the other seasons (0·048).Neutral detergent soluble (NDS) content was highest in A. semialata (29%) and lowest in E. plana (21·5%). Species similarly varied in the amount of potentially digestible cell wall (PDCW), with E. plana having the highest (57%) and C. dactylon the lowest (45·1%) PDCW content. Mean PDCW content was highest in spring (59·5 %) and lowest in winter (44·6%). Cell wall degradation (kc) rates were fastest (0·04) in C. dactylon and slowest in M. caffra (0·03). Overall, kc declined from spring (0·039) through to winter (0·029). In general, A. semialata, T. triandra and H. hirta appeared to have the most favourable, and E. plana, A. appendiculatusand M. caffra the least favourable, ruminal degradation characteristics. These differences suggest that species composition is likely to have a major impact on potential animal production on these low quality grasslands.

scholarly journals Persistence of ryegrass, tall fescue and cocksfoot following sequential annual sowings: pasture yield, composition and density in 3 establishment years under sheep grazing in Canterbury

2018 ◽  
pp. 169-176
Author(s):  
Thomas M R Maxwell ◽  
Grant R Edwards ◽  
Gerald P Cosgrove
Keyword(s):  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Block Design ◽  
Grass Species ◽  
Botanical Composition ◽  
Sheep Grazing ◽  
Sward Height ◽  
Long Term Effect ◽  
Forage Value

A long-term pasture persistence trial, consisting of repeated annual sowings, commenced in Canterbury in 2015 and is planned to continue until 2024. Preliminary results of the first 3 years sowings are reported. Each annual sowing used the same randomised block design of eight perennial ryegrass cultivars, one tall fescue and one cocksfoot cultivar, replicated four times. Grasses were drilled into a cultivated seedbed in autumn, with white clover broadcast-sown, then rolled with a Cambridge roller. Except for one 3-week spell in spring and in autumn to accumulate herbage to measure DM yield, botanical composition, morphology and sward density, plots were continuously stocked with sheep to maintain a 3-8 cm sward height from late-August to late-May. Results from the first 12 months following each of the three annual sowings (2015, 2016 and 2017) indicate establishment year had a greater influence on DM yield, botanical composition, grass leaf and stem proportions, and basal cover than did grass species or cultivar. Accumulating data from successive annual sowings and continued monitoring of each will help identify the long-term effect and difference between establishment years, as well as grass persistence traits for inclusion in the Forage Value Index ranking of perennial ryegrass cultivars.

scholarly journals Liveweight changes in lambs grazing six perennial ryegrass cultivars

1999 ◽  
pp. 31-35
Author(s):  
C.T. Westwood ◽  
M.G. Norriss
Keyword(s):  
New Zealand ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Dry Matter ◽  
Moisture Stress ◽  
Botanical Composition ◽  
Independent Research ◽  
Ewe Lambs ◽  
Research Organisation ◽  
Clover Content

Liveweight changes were measured for lambs grazing six high endophyte perennial ryegrasses, in a grazing experiment run by an independent research organisation in Canterbury, New Zealand. Ryegrass cultivars were sown under code in a binary mix with white clover in February 1997. Plots were strategically irrigated to avoid moisture stress, and stocked at approximately 27 Coopworth ewe lambs per ha in May 1997. Common pasture residual mass was maintained across cultivars by strategic addition of extra lambs, with extra grazing days recorded for each replicate. Lamb liveweight gains and botanical composition of replicates were assessed quarterly. Lamb liveweight gains differed significantly between treatments in Years 1 and 2 of this ongoing 3 year study. Lambs grazing 'Quartet' tetraploid perennial ryegrass gained, on average, 37.4 kg and 36.1 kg liveweight during Years 1 and 2 respectively, and together with 'Aries HD' (35.0 and 35.9 kg) produced significantly greater liveweight gain compared with 'Grasslands Nui' (22.0 and 23.7 kg) and 'Bronsyn' (22.5 and 24.1 kg), LSD0.05 = 6.0 and 7.4. Lambs grazing 'Embassy' gained 31.6 kg and 28.7 kg, and 'Vedette' 29.8 kg and 28.0 kg. Extra grazing days expressed as a percentage of base grazing days were between 3.8 and 6.7% across cultivars for Year 1 and between 2.0 and 6.5% across cultivars for Year 2. This study demonstrated significant differences in animal productivity between perennial ryegrass cultivars that produce comparable yields of dry matter. Differences may reflect variation in forage quality, endophyte toxins, clover content in the sward or other unidentified cultivar characteristics. Keywords: digestibility, endophyte, lamb, liveweight, perennial ryegrass, tetraploid

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