The growth and survival of young Mulga (Acacia aneura F. Muell) trees under different levels of grazing.

1985 ◽  
Vol 7 (2) ◽  
pp. 143 ◽  
Author(s):  
RF Brown
Keyword(s):  
Grazing Intensity ◽  
Growth And Survival ◽  
Continuous Grazing ◽  
Annual Consumption ◽  
C Stock ◽  
Complete Exclusion ◽  
Survival And Growth ◽  
Acacia Aneura ◽  
Possible Cause ◽  
Different Levels

The effects on the survival and growth of young mulga trees exposed to five levels of sheep graztng were monitored over bur years. The levels ranged from complete exclusion of domest~c stock to continuous grazing at a projected annual consumption rate of 20%, 35%, 50%, or 80% of the total available forage (grass, herbage, and accessible mulga leaf). Innially, all trees were less than 90 cm tall. Four years later, the ungrazed trees had more than doubled in he~ght whereas thegrazed trees were not significantly taller, irrespective of grazing intensity. Over 90% of the ungrazed trees had grown above the upper limit of sheep browsing (I20 cm) and their growth was considered unlikely to be prejudiced by subsequent grazing. Stem diameters nearly trebled in ungrazed mulga but much smaller Increases (averagmg25%) occurred in grazed plants. Overall, 36% of the young trees died. Most deaths occurred during the winter of 1980 and summer of 1982183 after protracted periods of dry weather. Grazing had little or no e,ffect on death rates. Even the lightest grazing arrested mulga growth and prevented the transition from low mulga to the tailer forms used for drought feeding. This is discussed as a possible cause of reported declines in drought reserves of mulga. The results of this study illustrate the need to ensure that grazing strategy is compatible with uninterrupted replacement of umbrella mulga (5-8 m high) cut for drought fodder.

scholarly journals Prunus Africana Provenances Growth and Survival Evaluation in the Highland of Awi zone, Amhara Region, North Western Ethiopia

2018 ◽  
Author(s):  
Abraham Demekristos
Keyword(s):  
Light Exposure ◽  
Seedling Survival ◽  
Block Design ◽  
Soil Water Potential ◽  
Mean Value ◽  
Good Growth ◽  
Growth And Survival ◽  
Prunus Africana ◽  
Survival And Growth ◽  
Establishment Rate

The aims of the study were to evaluate seedling growth and survival of Prunus africana provenances in awi highland based on ecological requirement of the tree. We measured survival and growth of three P.africana provenances seedlings found in Ethiopia (provenances sources namely: Gedeo, Jibat and Munnessa). Design of experiment with randomized complete block design (RCBD) with three replications. Seedlings planted at 2m, 2.5m and 3m distance between plants, plot, and blocks respectively. A plot size of 10mx10m and 25 plants are found per plot (0.01ha). We used ANOVA to test differences in survival, and growth among provenances over time. Results concluded that, provenances have no significant variation among in establishment rate, plant height and collar diameter growth. Of these provenances, Jibat was the first in establishment (56%), second in height (1.97m) and diameter (2.89cm). Gedeo was stood first in height (2.30m) but second in establishment rate (52%) and thickness(3.45cm), but Munessa with very good growth in diameter(3.59cm) might be prefreed for bark extraction followed by Gedeo, last in height (1.75m),but established second (52%). Contrary to expectations, seedlings were still at substantial risk of mortality ≥3 years after planting. Probably the plants survival rate and growth probably affected by altitude, soil water potential, light exposure, and wild animal presence in the surrounding. In steep slope sites, canopy shade, existing weed vegetation as well as wild animals such as apes is unlikely to enhance seedling survival after planting. Our results suggest that seedling mean growth increased with 0.008mm thickness and 0.41mm per day while 2.8mm thickness and 146.8mm tall increment recorded in 2560meter elevated high land or injibara with mean value of 18.5°C and rain fall is 1300mm.

scholarly journals The effect of temperature on the physiological condition and growth performance of freshwater eel elver Anguilla bicolor bicolor McClelland, 1844

2018 ◽  
Vol 17 (2) ◽  
pp. 181
Author(s):  
Latifa Fekri ◽  
Ridwan Affandi ◽  
Muhammad Fajar Rahardjo ◽  
Tatag Budiardi ◽  
Charles Parningotan Haratua Simanjuntak ◽  
...  
Keyword(s):  
Growth Performance ◽  
Physiological Condition ◽  
Effect Of Temperature ◽  
Aquatic Animal ◽  
Metabolism Rate ◽  
Randomized Design ◽  
Freshwater Eel ◽  
Survival And Growth ◽  
Physiology Laboratory ◽  
Different Levels

<p align="center"><strong>ABSTRACT</strong></p><p align="center"> </p><p>This study aimed to analyze the effect of water temperature on the physiological condition and growth performance of freshwater eel elver<em> Anguilla bicolor bicolor </em>(McClelland, 1844). This study was conducted in March 2017 at the Physiology Laboratory of Aquatic Animal, Faculty of Fisheries and Marine Sciences, Bogor Agricultural University. The study used a completely randomized design with five different levels of temperature (22<sup>°</sup>C, 24<sup>°</sup>C, 26<sup>°</sup>C, 28<sup>°</sup>C, and 30<sup>°</sup>C) as treatments with two replications. The size of elver was 2‒3 g. Fish were fed with 1 mm pellet containing 45% of protein. The feeding level was 7 % of fish biomass and the feeding frequency was two times a day. The results showed that temperatures range from 24‒30<sup>°</sup>C could be used for freshwater eel elver rearing and 28‒30<sup>°</sup>Cwere the best temperatures to support survival and growth performance of eel elver. A temperature of 24<sup>°</sup>C was the best temperature that could reduce the metabolism rate and did not cause stress on the elver.</p><p> </p><p>Keywords: elver, physiological conditions, growth performance, metabolism, temperature</p><p> </p><p> </p><p align="center"><strong>ABSTRAK</strong></p><p align="center"><strong> </strong></p><p>Penelitian dengan tujuan menganalisis pengaruh suhu terhadap kondisi fisiologis dan kinerja pertumbuhan <em>elver</em> ikan sidat (<em>Anguilla bicolor bicolor</em> McClelland, 1844) telah dilakukan pada bulan Maret 2017 di Laboratorium Fisiologi Hewan Air FPIK IPB. Penelitian menggunakan rancangan acak lengkap dengan lima perlakuan suhu berbeda (22<sup>°</sup>C, 24<sup>°</sup>C, 26<sup>°</sup>C, 28<sup>°</sup>C, dan 30<sup>°</sup>C) dengan masing-masing dua ulangan. Ukuran benih yang digunakan 2‒3 g. Pakan yang diberikan berupa pellet berukuran 1 mm dengan kadar protein 45%. Jumlah pakan yang diberikan (FR) adalah 7% dari biomassa ikan dan diberikan dua kali sehari. Hasil penelitian menunjukkan bahwa kisaran suhu 24‒30<sup>°</sup>C dapat digunakan dalam pemeliharaan <em>elver</em> ikan sidat, dan suhu 28‒30<sup>°</sup>C merupakan suhu yang sangat baik untuk mendukung kelangsungan hidup dan pertumbuhan <em>elver</em> ikan sidat. Suhu media 24<sup>°</sup>C adalah suhu terbaik yang dapat menekan laju metabolisme dengan tidak menyebabkan stres pada <em>elver </em>ikan sidat.</p><p> </p><p>Kata kunci: <em>elver</em>, kondisi fisiologis, kinerja pertumbuhan, metabolisme, suhu</p><p> </p><p> </p>

scholarly journals Immunocrit, colostrum intake, and preweaning body weight gain in piglets after split suckling based on birth weight or birth order1

2019 ◽  
Vol 3 (4) ◽  
pp. 1460-1465 ◽  
Author(s):  
Jodi M Morton ◽  
Austin J Langemeier ◽  
Theresa J Rathbun ◽  
Duane L Davis
Keyword(s):  
Body Weight ◽  
Birth Weight ◽  
Birth Order ◽  
Body Weight Gain ◽  
Growth And Survival ◽  
Prenatal Growth ◽  
Short Period ◽  
Survival And Growth ◽  
Improve Access ◽  
Preweaning Period

Abstract Preweaning survival and growth are compromised in litters with larger numbers of piglets. We evaluated two approaches for altering initial nursing with the goal to improve access to colostrum by groups of piglets that are known to have reduced access to colostrum. Therefore, we temporarily (1.5 h) removed either the heaviest six piglets in the litter (WT) or the first half of the piglets born (ORD) to provide a short period of nursing with reduced competition for the remaining piglets. We found that WT piglets were heavier (P ≤ 0.05) at 7 d after farrowing and gained more body weight (BW) from farrowing to day 7 than control (CON) piglets which were raised in litters with ad libitum nursing during the same period. Further, we found that the heaviest piglets consumed more (P &lt; 0.001) colostrum and gained more (P &lt; 0.001) BW during the preweaning period but did not have (P &gt; 0.10) greater immunocrits. Although ORD piglets had similar colostrum intake, immunocrits, and preweaning weights as controls, we found that overall the piglets born in the first half of litters had greater (P &lt; 0.01) immunocrits than piglets born in the last half of the litter. Therefore, both birth weight and birth order have effects on traits that are important for prenatal growth and survival, but they differ in that birth weight is more closely related to colostrum intake and birth order affects immunocrit.

Early Survival and Growth of Russian Pinus sylvestris L. in Canada

1970 ◽  
Vol 46 (4) ◽  
pp. 325-328
Author(s):  
A. H. Teich ◽  
M. J. Holst
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
High Performance ◽  
Jack Pine ◽  
Stem Form ◽  
Growth And Survival ◽  
Growing Seasons ◽  
Survival And Growth ◽  
Continental Climate ◽  
Better Than

Scots pine provenances from Russia were grown in Ontario at Longlac, Dorset and Chalk River, and in Saskatchewan at Prince Albert and Indian Head. After eight growing seasons in the field all provenances survived well. The three tallest, Orel, Woronesh and Kiev provenances, grew considerably taller than the others, and at Prince Albert, where native jack pine was also grown, the growth and survival of these provenances was also better than that of jack pine. If further studies show that this high performance persists and that stem form is commercially acceptable, seedlings from these three provenances may be useful for reforestation in those parts of Canada with a continental climate.

The influence of grazing frequency and intensity on the vigour of Lolium perenne L. under subtropical conditions

1996 ◽  
Vol 47 (6) ◽  
pp. 975 ◽  
Author(s):  
FR McKenzie
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Grazing Intensity ◽  
Early Summer ◽  
Grazing Management ◽  
Lolium Perenne L ◽  
Continuous Grazing ◽  
Second Year

Lolium perenne L. (perennial ryegrass) exhibits poor persistence in subtropical environments. Grazing management may enhance the vigour and hence persistence of this species. Perennial ryegrass was subjected to various grazing treatments, and its vigour, indexed by etiolated growth, was evaluated over 2 years. Pasture and individual tiller vigour were monitored under 5 combinations of grazing frequency and intensity, applied rotationally, and 1 treatment of continuous grazing. The vigour of infrequently grazed plots was greater than that of frequently or continuously grazed plots; however, grazing intensity did not influence vigour. Seasonally, vigour declined during mid (December and .January) to late (February and March) summer of the establishment year and from early summer (October) to autumn (May) during the second year. Poor vigour in frequently grazed plots was associated with low growth reserves rather than a lack of active tiller growth points. Towards the end of the second year, however, a lack of active tiller growth points also limited vigour in frequently grazed plots. Tillers from infrequently grazed plots (regardless of grazing intensity) had greater vigour than tillers from the frequently grazed plots. To enhance the vigour of perennial ryegrass in subtropical environments, the frequency of grazing should be reduced, particularly in summer.

scholarly journals Growth and survival of the pearl oyster Pteria hirundo (L.,1758) in an intermediate stage of culture in Santa Catarina, Brazil

2012 ◽  
Vol 72 (1) ◽  
pp. 175-180 ◽  
Author(s):  
MCP Albuquerque ◽  
R Alves ◽  
ACV Zanandrea ◽  
JF Ferreira ◽  
CMR Melo ◽  
...  
Keyword(s):  
Culture System ◽  
Intermediate Stage ◽  
Pearl Oyster ◽  
Average Increase ◽  
Southern Brazil ◽  
Growth And Survival ◽  
Life Conditions ◽  
Pearl Oysters ◽  
Survival And Growth ◽  
Closed Environment

There are no records in Brazil for the culture of Pteridae family oysters, genus Pteria and Pinctada. The intermediate culture can be considered one of the critical stages during the oyster farming. The changes in life conditions from a semi-closed environment provided by the collector to the structures utilized for the growth represents a considerable stress factor to which the animals are subjected. The goal of the present study was to evaluate the growth and survival of the pearl oyster Pteria hirundo (Linnaeus, 1758) kept in intermediate lanterns. Seeds of P. hirundo, obtained through larviculture carried out at the Marine Molluscs Laboratory (UFSC), southern Brazil were detached from the collectors, transferred and kept in an intermediate culture system (oyster lantern). During 6 months, growth (dorso-ventral height - DVH in mm) and survival (%) were evaluated. Two size classes were tested: medium (M), between 3.4 and 4.4 mm, and large (L), bigger than 4.5 mm. The density of occupation in each floor of the lantern was 50%. At the end of the experiment, the survivals observed were 90 and 94% for the sizes M and L, respectively. Medium juveniles of Pteria hirundo had an average (Std) increase of 16.1 (±4.38) mm in the dorso-ventral height, and large juveniles an average increase of 11.4 (±3.77) mm after six months of experiment. The results observed during the intermediate stage of cultivation indicate that Pteria hirundo presents survival and growth similar to other species of pearl oysters traditionally used in the pearl industry in several countries.

An analysis of growth of different cattle genotypes reared in different environments

1984 ◽  
Vol 103 (1) ◽  
pp. 137-153 ◽  
Author(s):  
J. E. Frisch ◽  
T. E. Vercoe
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
High Growth ◽  
Environmental Stresses ◽  
Growth Potential ◽  
Gastrointestinal Helminths ◽  
Treatment Groups ◽  
Survival And Growth ◽  
Different Levels ◽  
High Growth Potential

SummaryCalves from three breeds, Brahman, Hereford × Shorthorn (HS) and Brahman × HS (BX), were divided equally into two groups, one of which was treated every 3 weeks from birth onwards to control ticks and gastrointestinal helminths, and one of which was untreated. Mortalities, growth rates and levels of resistance to environmental stresses that affected both mortality and growth under grazing conditions were recorded for all animals up to weaning (6 months) and for all males up to 15 months of age. The Brahmans were the most and the HS were the least resistant to environmental stresses, each of which was shown to depress growth in proportion to its magnitude and to contribute to the high mortalities of the HS. All breeds responded positively to parasite control with the greatest response in both survival and growth in the HS breed and the least response in the Brahman breed.Samples of males from the various breed-treatment groups were taken into pens where they were protected from environmental stresses and fed both low-quality pasture hay and high-quality lucerne hay ad libitum. Measurements were made of fasting metabolism, maintenance requirement, voluntary food intake and gain, variables related to the growth potential of each animal. The HS animals had the highest whilst the Brahmans had the lowest values for each variable.However, despite their low growth potential, the Brahmans had the highest growtli rate, and the HS, despite their high growth potential, had the lowest growth rate, when growth was measured in the presence of all environmental stresses. When parasites were controlled, growth rates were highest for the BX, the breed with intermediate growtli potential, and did not differ between the HS and Brahmans. These interactions arose because of the different contributions of resistance to environmental stresses and growth potential to growth rate measured at the different levels of environmental stresses. The relevance of these interactions to breed evaluation and cross-breeding is considered.Growth potential and resistance to environmental stresses were negatively correlated both between and within breeds, though the latter was biased by the effects of compensation. The influence of these relationships on the likely outcome of selection for increased growth rate, both between and within breeds, is discussed.

scholarly journals Embryonic exposure to conspecific chemicals suppresses cane toad growth and survival

2011 ◽  
Vol 8 (2) ◽  
pp. 226-229 ◽  
Author(s):  
Michael R. Crossland ◽  
Richard Shine
Keyword(s):  
Chemical Cues ◽  
Ecological Impacts ◽  
Cane Toad ◽  
Growth And Survival ◽  
Rhinella Marina ◽  
Embryonic Exposure ◽  
Body Sizes ◽  
Tropical Australia ◽  
Survival And Growth ◽  
Invasive Taxa

Adaptations to suppress the viability of conspecifics may provide novel ways to control invasive taxa. The spread of cane toads ( Rhinella marina ) through tropical Australia has had severe ecological impacts, stimulating a search for biocontrol. Our experiments show that cane toad tadpoles produce waterborne chemical cues that suppress the viability of conspecifics encountering those cues during embryonic development. Brief (72 h) exposure to these cues in the egg and post-hatching phases massively reduced rates of survival and growth of larvae. Body sizes at metamorphosis (about three weeks later) were almost twice as great in control larvae as in tadpole-exposed larvae. The waterborne cue responsible for these effects might provide a weapon to reduce toad recruitment within the species' invaded range.

Industrial Research and Firm Size, Survival, and Growth in American Manufacturing, 1921–1946: An Assessment

1983 ◽  
Vol 43 (4) ◽  
pp. 953-980 ◽  
Author(s):  
David C. Mowery
Keyword(s):  
Firm Size ◽  
Small Firms ◽  
Firm Growth ◽  
Industrial Research ◽  
Large Firms ◽  
Research Activity ◽  
Growth And Survival ◽  
Survival And Growth ◽  
The Impact ◽  
The Relationship

The literature on the development of American industrial research suggests that during the twentieth century large firms “dominated” industrial research, and reaped the majority of the benefits from such activity. This paper utilizes new data to analyze both the relationship between firm size and research employment and the impact of research activity on firm growth and survival during 1921–1946. The results suggest that large firms were no more research-intensive than were small firms during the 1921–1946 period. Research activity significantly enhanced the probability of firms' survival among the ranks of the 200 largest manufacturing firms during 1921–1946. Research employment also improved the growth performance of both large and small firms during 1933–1946.

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