Foraging ecology of the agile wallaby (Macropus agilis) in the wet - dry tropics

2002 ◽  
Vol 29 (4) ◽  
pp. 347 ◽  
Author(s):  
Simon C. Stirrat
Keyword(s):  
Seasonal Changes ◽  
Diet Composition ◽  
Foraging Ecology ◽  
Foraging Strategy ◽  
In Vitro Digestibility ◽  
Wet Season ◽  
Dry Tropics ◽  
Seasonal Environment ◽  
Herbage Quality

Seasonal changes in diet composition and diet preferences of the agile wallaby (Macropus agilis) were investigated in East Point Reserve, Darwin. The wallabies were almost exclusively grazers in the wet season when the nitrogen content and in vitro digestibility of herbage were high. Evidence suggests that wallabies rarely browsed in the wet season. The diet consisted mainly of non-leguminous forbs, reflecting the abundance of these plants in the study site, but the wallabies showed higher preference for grasses and legumes. In the dry season herbage quality was poor and the wallabies grazed on available green grasses and forbs but also broadened their diet considerably to include a range of alternative foods, including browse, leaf litter, fruits, flowers and roots. A flexible foraging strategy allows agile wallabies to exploit a range of resources in this highly seasonal environment where periods of food shortage may be long and their duration unpredictable.

scholarly journals Seasonal changes in water quality and macrophytes and the impact of cattle on tropical floodplain waterholes

2012 ◽  
Vol 63 (9) ◽  
pp. 788 ◽  
Author(s):  
N. E. Pettit ◽  
T. D. Jardine ◽  
S. K. Hamilton ◽  
V. Sinnamon ◽  
D. Valdez ◽  
...  
Keyword(s):  
Water Quality ◽  
Seasonal Changes ◽  
Aquatic Macrophyte ◽  
Plant Cover ◽  
Critical Role ◽  
Dry Season ◽  
Nutrient Concentrations ◽  
Wet Season ◽  
Dry Tropics ◽  
The Impact

The present study indicates the critical role of hydrologic connectivity in floodplain waterholes in the wet–dry tropics of northern Australia. These waterbodies provide dry-season refugia for plants and animals, are a hotspot of productivity, and are a critical part in the subsistence economy of many remote Aboriginal communities. We examined seasonal changes in water quality and aquatic plant cover of floodplain waterholes, and related changes to variation of waterhole depth and visitation by livestock. The waterholes showed declining water quality through the dry season, which was exacerbated by more frequent cattle usage as conditions became progressively drier, which also increased turbidity and nutrient concentrations. Aquatic macrophyte biomass was highest in the early dry season, and declined as the dry season progressed. Remaining macrophytes were flushed out by the first wet-season flows, although they quickly re-establish later during the wet season. Waterholes of greater depth were more resistant to the effects of cattle disturbance, and seasonal flushing of the waterholes with wet-season flooding homogenised the water quality and increased plant cover of previously disparate waterholes. Therefore, maintaining high levels of connectivity between the river and its floodplain is vital for the persistence of these waterholes.

The influence of weather on the quality of tropical legume pasture during the dry season in northern Australia. III. Effects of digestibility and chemical composition

1989 ◽  
Vol 40 (3) ◽  
pp. 573 ◽  
Author(s):  
RL McCown ◽  
BH Wall
Keyword(s):  
Dry Matter ◽  
Mediterranean Climate ◽  
Dry Season ◽  
In Vitro Digestibility ◽  
Northern Australia ◽  
Pasture Legumes ◽  
Dry Matter Digestibility ◽  
Dry Tropics

In the semi-arid tropics, accumulated shed leaf of certain pasture legumes can provide highly nutritious feed for cattle in the dry season. Previous papers in this series have dealt with the fungal spoilage of leaf of Caribbean stylo in response to dew and unseasonal rainfall and the threat to acceptability by cattle. This paper focuses on the effects of varying degrees of moulding and leaching on dry matter digestibility of leaf of this legume. Uniform leaf material of high digestibility was exposed at six locations during the dry season and samples retrieved at 4-weekly intervals. From initial values of 75%. in vitro digestibility dropped to as low as 50%. Degree of moulding, as indicated by a quantitative index of discoloration, accounted for about 80�/o of loss. Moulding was much more important than leaching. This latter finding in the winter-dry tropics contrasts with previous findings in the summer-dry Mediterranean climate.

Seasonal changes in the proportion and quality of plant parts of nine Stylosanthes lines

1982 ◽  
Vol 22 (119) ◽  
pp. 391
Author(s):  
CJ Gardener ◽  
RG Megarrity ◽  
MN McLeod
Keyword(s):  
Nutritive Value ◽  
Significant Proportion ◽  
Moisture Stress ◽  
Winter Period ◽  
In Vitro Digestibility ◽  
Wet Season ◽  
Plant Parts ◽  
Similar Chemical ◽  
Nitrogen Phosphorus

The distribution of dry matter between leaves, stems and inflorescences, and the nitrogen, phosphorus and sulfur concentration and in vitro digestibility of these parts were measured in uncut swards of nine accessions of seven Stylosanthes spp. grown in northern Queensland over 22 months. Despite above average rainfall in both dry seasons, which greatly reduced the normal moisture stress, only S. guianensis cv. Oxley retained a significant proportion of green leaf in the winter period. However, Oxley set little seed in either year. Plants of the three short-lived species S. hamata, S. humilis and S. subsericea died back to the crown at the end of each wet season, while adult plants of the strongly perennial shrubs S. viscosa, S. scabra and S. fruticosa shed most of their leaves by July. All accessions flowered in both years, and all, except Oxley, set a heavy seed crop by the second year. Some inflorescence was retained on the living stems of the perennial lines until October. This inflorescence had a nutritive value only just below that of young leaf, while the mature stem was low in nitrogen and digestibility in all accessions. The leaf and stem litter had a similar chemical composition to standing material but rapidly became mouldy. The two cultivars of S. humilis, Paterson and Gordon, and S. subsericea had significantly higher levels of nitrogen, phosphorus, sulfur and digestibility than the other accessions. S. viscosa had significantly lower levels of all four attributes. The utilization of the various accessions for improving cattle nutrition is discussed.

Correction - Seasonal changes in the proportion and quality of plant parts of nine Stylosanthes lines

1982 ◽  
Vol 22 (119) ◽  
pp. 391 ◽  
Author(s):  
CJ Gardener ◽  
RG Megarrity ◽  
MN McLeod
Keyword(s):  
Nutritive Value ◽  
Significant Proportion ◽  
Moisture Stress ◽  
Winter Period ◽  
In Vitro Digestibility ◽  
Wet Season ◽  
Plant Parts ◽  
Similar Chemical ◽  
Nitrogen Phosphorus

The distribution of dry matter between leaves, stems and inflorescences, and the nitrogen, phosphorus and sulfur concentration and in vitro digestibility of these parts were measured in uncut swards of nine accessions of seven Stylosanthes spp. grown in northern Queensland over 22 months. Despite above average rainfall in both dry seasons, which greatly reduced the normal moisture stress, only S. guianensis cv. Oxley retained a significant proportion of green leaf in the winter period. However, Oxley set little seed in either year. Plants of the three short-lived species S. hamata, S. humilis and S. subsericea died back to the crown at the end of each wet season, while adult plants of the strongly perennial shrubs S. viscosa, S. scabra and S. fruticosa shed most of their leaves by July. All accessions flowered in both years, and all, except Oxley, set a heavy seed crop by the second year. Some inflorescence was retained on the living stems of the perennial lines until October. This inflorescence had a nutritive value only just below that of young leaf, while the mature stem was low in nitrogen and digestibility in all accessions. The leaf and stem litter had a similar chemical composition to standing material but rapidly became mouldy. The two cultivars of S. humilis, Paterson and Gordon, and S. subsericea had significantly higher levels of nitrogen, phosphorus, sulfur and digestibility than the other accessions. S. viscosa had significantly lower levels of all four attributes. The utilization of the various accessions for improving cattle nutrition is discussed.

scholarly journals Physiochemical quality and nutritional value of ensiled fresh maize stover and groundnut haulms in wet season for sustainable ruminant production

2021 ◽  
Vol 47 (6) ◽  
pp. 141-152
Author(s):  
A. A. Lamidi ◽  
J. N. Ingweye
Keyword(s):  
Proximate Composition ◽  
Dry Matter ◽  
Nutritional Value ◽  
In Vitro Digestibility ◽  
Wet Season ◽  
Nutritional Factors ◽  
Maize Stover ◽  
Valeur Nutritionnelle ◽  
Experimental Treatments

The study was conducted to evaluate the physiochemical quality and nutritional value of ensiled fresh maize stover and groundnut haulms for wet season sustainable ruminant production. Fresh maize stover and fresh groundnut haulms were collected, wilted for 3 – 4 days, chopped and ensiled in different proportions to make three (3) experimental treatments (T1: 100% maize stover; T2:100 % groundnut haulms; T3:50 % maize stover and 50 % groundnut haulms) and replicated four (4) times in glass Bamma® bottles for 30 days. Physical features, proximate composition, mineral profile, anti-nutritional factors, post invitro digestibility characteristics and nutritional values of the silages were examined. Results showed that the colour of the silage were cream, greenish brown and light brown for T1, T2 and T3, respectively. Texture was smooth for T1, coarse for T2 and slightly coarse for T3. All the silages were moist with pleasant aroma. The pH and temperature value ranges from 3 – 4.5, 30 – 31.5oC, respectively. There were significant differences (P<0.05) in the proximate composition, fiber fractions, minerals, anti-nutritional factors and the post in-vitro digestibility characteristics of the silages. Silage T3 (50 % maize stover and 50 % groundnut haulms) had highest (P<0.05) significant content for the parameters considered. Similar (P>0.5) nutritive value (Dry matter intake (DMI), digestible dry matter (DDM), and relative feed value (RFV)) were recorded for the experimental treatments. The values observed for DMI, DDM and RFV ranged from 2.44 – 2.45, 67.62 – 67.67 and 127.86 – 127.98, respectively. Conclusively, the silage exhibited good physiochemical quality and nutritional value that justified its potential in solving the challenges of dry season feeding. Treatment 3 (50% maize stover and 50% groundnut haulms) is recommended for ruminant farmers.   L'étude a été menée pour évaluer la qualité physico-chimique et la valeur nutritionnelle des tiges de maïs frais ensilées et des fanes d'arachide pour la production durable de ruminants en saison humide. Les tiges de maïs frais et les fanes d'arachide fraîches ont été collectées, fanées pendant 3 à 4 jours, hachées et ensilées dans des proportions différentes pour faire trois (3) traitements expérimentaux (T1 : 100% de tiges de maïs ; T2 : 100% de fanes d'arachide ; T3 : 50% tiges de maïs et 50% de fanes d'arachide) et répliquées quatre (4) fois dans des bouteilles en verre Bamma® pendant 30 jours. Les caractéristiques physiques, la composition immédiate, le profil minéral, les facteurs anti-nutritionnels, les caractéristiques de digestibilité post-in vitro et les valeurs nutritionnelles des ensilages ont été examinés. Les résultats ont montré que la couleur de l'ensilage était crème, brun verdâtre et brun clair pour T1, T2 et T3, respectivement. La texture était lisse pour T1, grossière pour T2 et légèrement grossière pour T3. Tous les ensilages étaient humides avec un arôme agréable. La valeur du pH et de la température varie respectivement de 3 à 4,5 et 30 à 31,5 ° C. Il y avait des différences significatives (P <0,05) dans la composition immédiate, les fractions de fibres, les minéraux, les facteurs anti-nutritionnels et les caractéristiques de digestibilité post-invitro des ensilages. L'ensilage T3 (50% de tiges de maïs et 50% de fanes d'arachide) avait la teneur significative la plus élevée (P <0,05) pour les paramètres considérés. Des valeurs nutritives similaires (P> 0,5) (ingestion de matière sèche (DMI), matière sèche digestible (DDM) et valeur d'alimentation relative (RFV)) ont été enregistrées pour les traitements expérimentaux. Les valeurs observées pour le 'DMI', le 'DDM' et le 'RFV' allaient respectivement de 2,44 à 2,45, 67,62 à 67,67 et 127,86 à 127,98. En conclusion, l'ensilage présentait une bonne qualité physico-chimique et une valeur nutritionnelle qui justifiaient son potentiel à résoudre les défis de l'alimentation en saison sèche. Le traitement 3 (50% de tiges de maïs et 50% de fanes d'arachide) est recommandé pour les éleveurs de ruminants.

Diet composition of cattle grazing Stylosanthes - grass pastures in the seasonally dry tropics: the effect of phosphorus as fertiliser or supplement

1998 ◽  
Vol 38 (1) ◽  
pp. 7 ◽  
Author(s):  
D. B. Coates ◽  
R. P. Le Feuvre
Keyword(s):  
Diet Composition ◽  
Isotope Analysis ◽  
Cattle Grazing ◽  
Diet Selection ◽  
Wet Season ◽  
Seasonally Dry ◽  
Stylosanthes Hamata ◽  
Dry Tropics ◽  
Extractable P ◽  
Induced Changes

Summary. The effect of phosphorus (P) on diet selection in cattle grazing pastures based on Stylosanthes hamata cv. Verano andS. scabra cv. Seca in the seasonally dry tropics was studied in 3 grazing trials on soils with inherently low P status ( 5 µg/g bicarbonate-extractable P). The contribution of Stylosanthes (stylo) to diets was estimated at regular intervals (approximately monthly) using carbon isotope analysis of faeces. Feeding P supplement increased the proportion of stylo in the diet but the effect was seasonal and variable, being most pronounced during the late wet and early dry seasons when dietary stylo proportions are usually highest. The results indicated that P supplement influenced diet selection through its effect on dietary P status such that cattle with a deficiency of dietary P select a lower proportion of stylo than those with higher P intakes. The effect of fertiliser P on dietary stylo content was also variable. The dominant effect was via fertiliser-induced changes in pasture botanical composition. Higher stylo proportions in the diet of heifers grazing unfertilised pasture compared with those grazing fertilised pasture were associated with increasing stylo dominance in unfertilised pastures as opposed to grass dominance in fertilised pastures. At the same time there was evidence of a fertiliser treatment effect that was consistent with dietary P status influencing diet composition. In the grass-dominant pastures, unsupplemented cattle on low P pasture selected less stylo than those grazing pastures of higher P status due to more frequent fertilising but there was no difference where P supplement was fed. A strong seasonal preference for grass early in the wet season, reinforced by a generally reduced preference for stylo in cattle with diets deficient in P, probably hastened the development of stylo dominance in unfertilised pasture where P supplement was not fed.

Land Condition in the Tropical Tall Grass Pasture Lands. 2. Effects on Herbage Quality and Nutrient Uptake.

1995 ◽  
Vol 17 (1) ◽  
pp. 86 ◽  
Author(s):  
AJ Ash ◽  
JG Mcivor
Keyword(s):  
Nitrogen Concentration ◽  
Phosphorus Uptake ◽  
Phosphorus Concentration ◽  
In Vitro Digestibility ◽  
Nitrogen And Phosphorus ◽  
Tall Grass ◽  
Herbage Quality ◽  
Land Condition ◽  
Nitrogen And Phosphorus Uptake

Herbage quality (in vitro digestibility, nitrogen and phosphorus concentrations) of plucked samples, and above ground nutrient uptakes (nitrogen and phosphorus) were compared on plots differing in land condition at 10 sites in northern Australia. Over all sites there was a significant increase in digestibility and nitrogen concentration, and a significant decrease in phosphorus concentration, as land condition declined. Both nitrogen and phosphorus uptake decreased as land condition declined. The results indicate that diet quality may be higher from land in poor condition. However, the large decrease in pasture productivity associated with declining land condition may more than offset this apparent improvement in feed quality.

Seasonal changes in the growth, dry matter distribution and herbage quality of three native grasses in northern Queensland

1981 ◽  
Vol 21 (113) ◽  
pp. 600 ◽  
Author(s):  
JG McIvor
Keyword(s):  
Seasonal Changes ◽  
Dry Matter ◽  
Perennial Grasses ◽  
Green Leaf ◽  
In Vitro Digestibility ◽  
Matter Distribution ◽  
Nitrogen And Phosphorus ◽  
Dry Matter Distribution ◽  
Heteropogon Contortus

The growth of unfertilized native pasture was studied at two sites (Lansdown near Townsville and Redlands near Charters Towers) over a 30-month period. Seasonal changes in the dry matter distribution between green leaf, green stem, dry leaf, dry stem and inflorescence, and the nitrogen and phosphorus concentrations and in vitro digestibility of these components were measured in Chrysopogon fallax, Heteropogon contortus and Themeda australis. Maximum herbage yields ranged from 4000-6000 kg/ha at Lansdown and 1500-2000 kg/ha at Redlands with perennial grasses contributing over 90% of the herbage. There were large differences between the species in the pattern of dry matter distribution, with C. fallax having a higher proportion of leaf during most of the sampling period. The nitrogen and phosphorus concentrations and digestibility levels in the various plant components were usually similar in the three grasses but all showed large seasonal variations at both sites. Green leaf was the most nutritious component but even this was of too low a quality to support animal growth during part of the year.

Pasture management in semiarid tropical woodlands: improving the herbage quality of stylos and grasses

2007 ◽  
Vol 47 (11) ◽  
pp. 1359 ◽  
Author(s):  
John G. McIvor
Keyword(s):  
Phosphorus Concentration ◽  
In Vitro Digestibility ◽  
Stocking Rate ◽  
Nitrogen And Phosphorus ◽  
Pasture Management ◽  
Buffel Grass ◽  
North East ◽  
Herbage Quality

The impacts of season and pasture management (tree killing, superphosphate application, stocking rate) on the herbage quality of stylos and grasses were measured at Hillgrove and Cardigan, north-east Queensland. Plucked samples of Verano, Seca and buffel grass (both sites) and a native grass (spear grass at Cardigan and desert blue grass at Hillgrove) were collected over a 4-year period and concentrations of nitrogen, phosphorus and sulfur and in vitro digestibility were measured. There were large seasonal variations in herbage quality of all species with high quality in the early growing season and low quality in dry periods. The stylos had higher nitrogen concentrations and in vitro digestibilities than the grasses, buffel grass had a higher phosphorus concentration than the other species and there were no consistent differences in sulfur concentration between species. Buffel grass generally had higher nitrogen and phosphorus concentrations and in vitro digestibility than the native grasses. Management had relatively minor impacts but where differences did occur, herbage quality was higher in plots with live trees than where trees were killed, on plots where superphosphate was applied compared with plots without fertiliser and was greater at high stocking rate. Oversowing native pastures with stylos had no effect on the herbage quality of desert blue grass which had similar quality in oversown pasture and native pasture.

scholarly journals PASTURE UTILISATION AND ITS EFFECT ON HERBAGE QUALITY

1985 ◽  
pp. 221-225
Author(s):  
S.M. Francis ◽  
M.L. Smetham
Keyword(s):  
In Vitro Digestibility ◽  
Silt Loam ◽  
Rotational Grazing ◽  
Material Content ◽  
Herbage Quality ◽  
Dead Material ◽  
Stocking Rates ◽  
Different Levels ◽  
Lincoln College

An existing grazing trial on an irrigated Wakanui silt loam at Lincoln College, Canterbury, was sampled at five consecutive grazings (January to July, 1983) to determine the effects of pasture utilisation on herbage composition and in vitro digestibility of regrowth. Rotational grazing of sheep at two stocking rates, high (27.5 ewes/ha) and low (17.5 ewes/ha), resulted in different levels of utilisation. Low utilisation (27%) produced a sward with a high dead material content (44%) and low in vitro digestibility of the whole sward (

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