Game domestication for animal production in Kenya: the nutritional ecology of oryx, zebu cattle and sheep under free-range conditions

1985 ◽  
Vol 104 (2) ◽  
pp. 375-382 ◽  
Author(s):  
M. R. Stanley Price
Keyword(s):  
Rank Order ◽  
Feeding Habits ◽  
Nutritional Ecology ◽  
Dry Season ◽  
Selection Combining ◽  
Zebu Cattle ◽  
Wet Season ◽  
Interspecific Differences ◽  
Dry Conditions ◽  
Nitrogen Concentrations

SummaryObservations on oryx, sheep and cattle under natural grazing conditions in both a wet and a dry season are given and discussed.Dry faecal outputs by the sheep and oryx were less in the wet than in the dry season. Output by the cattle was greater than both, and showed little seasonal difference. Faecal nitrogen concentrations showed no interspecific overlap, in the rank order sheep > oryx > cattle. All were greater in the wet season, and the rank order maintained.Drinking water intakes were similar for oryx and sheep in both seasons. The cattle's water intake was greater in the wet season. Expressed as ml/kg W0·85/day, there were no overlaps in species' mean intakes, in the order cattle > sheep > oryx, in the ratio 100:57:24. In the dry season, the herd walked 16 km on non-drinking days, and a further 7 km on alternate days when receiving water. Under wetter conditions with more forage available, the herd walked only 11 km daily.Slight interspecific differences in the times spent walking, feeding, standing and lying were found over a 48 h period. In the wet season less time was spent walking and feeding, with corresponding increases in the other activities. The oryx were notable in that rumination occupied far less of their daytime activity than for the sheep or cattle although the total times spent ruminating were similar.The results are discussed in relation to differences in the species’ feeding habits and strategies of diet selection, combining the grazing results with observations from penned animals on a common diet. The intakes of water agree with the results from penned animals, confirming oryx's adaptation to hot, dry conditions. The advantages of a low water requirement, met by intermittent drinking, are discussed.The possible detrimental effects on productivity of a regime of day-grazing and night-penning under hot conditions are discussed. In the light of these, some advantages to oryx of scheduling its rumination to the night hours are suggested.

Patterns and correlates of interspecific variation in foliar insect herbivory and pathogen attack in Brazilian cerrado

2001 ◽  
Vol 17 (1) ◽  
pp. 127-148 ◽  
Author(s):  
ROBERT J. MARQUIS ◽  
IVONE R. DINIZ ◽  
HELENA C. MORAIS
Keyword(s):  
Plant Species ◽  
Interspecific Variation ◽  
Dry Season ◽  
Mature Leaf ◽  
Insect Damage ◽  
Wet Season ◽  
Leaf Production ◽  
Leaf Toughness ◽  
Interspecific Differences ◽  
Pathogen Attack

Patterns of insect herbivore and leaf pathogen attack are described for 25 plant species (10 trees, 10 shrubs and five herbs) at a Brazilian savanna (cerrado) site. Plant and leaf traits were correlated with interspecific variation in attack by herbivores and pathogens in order to account for differences among plant species. Across all species, pathogen damage was 1.5 times higher than insect damage (17.3% vs. 6.8%, respectively). Most insect damage occurred to young leaves while they were expanding (end of the dry season). In contrast, pathogen attack was low on young expanding leaves at the end of the dry season, increased as those leaves matured in the wet season, but continued to increase through the next dry season. Protein-binding capacity was negatively associated with interspecific differences in insect damage to mature leaves. Protein availability and plant height were positive predictors of pathogen attack among plant species, while leaf expansion rate was a significant negative predictor. Interspecific differences in leaf phenology had little effect on the amount of damage caused by either insects or pathogens. However, new leaves produced during the wet season suffered less insect damage than leaves produced during the dry season, the time of greatest leaf production. Timing of young leaf production affected pathogen attack but the season of escape depended on plant species. In contrast, there was no evidence for escape in space as common species were less likely to suffer high pathogen attack than rare species. New and mature leaf toughness, and time for a leaf to reach full expansion all increased from herbs to shrub to trees, while mature leaf nitrogen decreased in that order.

Ecology of the Asian elephant in southern India. II. Feeding habits and crop raiding patterns

1990 ◽  
Vol 6 (1) ◽  
pp. 33-53 ◽  
Author(s):  
R. Sukumar
Keyword(s):  
Feeding Habits ◽  
Natural Habitat ◽  
Foraging Strategy ◽  
Dry Season ◽  
Southern India ◽  
Crop Raiding ◽  
Wet Season ◽  
Seasonal Movement ◽  
Food Requirement ◽  
Optimal Foraging Strategy

ABSTRACTThe Asian elephant's foraging strategy in its natural habitat and in cultivation was studied in southern India during 1981–83. Though elephants consumed at least 112 plant species in the study area, about 85% of their diet consisted of only 25 species from the order Malvales and the families Leguminosae, Palmae, Cyperaceae and Gramineae. Alteration between a predominantly browse diet during the dry season with a grass diet during the early wet season was related to the seasonally changing protein content of grasses.Crop raiding, which was sporadic during the dry season, gradually increased with more area being cultivated with the onset of rains. Raiding frequency reached a peak during October-December, with some villages being raided almost every night, when finger millet (Eleusine coracana) was cultivated by most farmers. The monthly frequency of raiding was related to the seasonal movement of elephant herds and to the size of the enclave. Of their total annual food requirement, adult bull elephants derived an estimated 9.3% and family herds 1.7% in quantity from cultivated land. Cultivated cereal and millet crops provided significantly more protein, calcium and sodium than the wild grasses. Ultimately, crop raiding can be thought of as an extension of the elephant's optimal foraging strategy.

The water intake of milking cows grazing Pangola grass (Digitaria decumbens Stent.) under wet- and dry-season conditions in Trinidad

1962 ◽  
Vol 58 (2) ◽  
pp. 257-264 ◽  
Author(s):  
P. N. Wilson ◽  
M. A. Barratt ◽  
M. H. Butterworth
Keyword(s):  
Water Intake ◽  
Free Water ◽  
Dry Season ◽  
Feed Water ◽  
Zebu Cattle ◽  
Wet Season ◽  
Drinking Habits ◽  
Digitaria Decumbens ◽  
Coefficients Of Variation ◽  
The Mean

1. The water intakes of ten Holstein × Zebu milking cows, yielding between one and two gallons of milk a day, were analysed on the basis of (a) freewater drunk, and (b) feed-water consumed with the herbage. Trials took place during a 10-day period in both the wet season, 1959 and the dry season, 1960. During both seasons the cows were rotationally grazed on Pangola grass pastures.2. The results showed a difference of only 24% in total water intake between seasons. However, the mean intake of free water increased from 18·5 lb. per cow in the wet season to 81·5 lb. per cow per day in the dry season, and the intake of feed water decreased from 94·9 to 59·2 lb. per cow per day, respectively. The between cow coefficients of variation were 9·7 and 8·7%, respectively.3. Results are presented for the drinking habits of Holstein × Zebu cattle grazing Pangola grass pastures. For 567 observed cow-days in the wet season, the cattle were found to drink water on average 0·8 times per day from troughs present in the pastures. For 332 observed cow-days in the dry season, the cattle increased their drinking habits to a mean figure of 1·4 times each day.

A study of the growth rate of F2 and F3 Africander cross, Brahman cross and British cross cattle from birth to 18 months in a tropical environment

1971 ◽  
Vol 11 (53) ◽  
pp. 593 ◽  
Author(s):  
JF Kennedy ◽  
GIK Chirchir
Keyword(s):  
Growth Rate ◽  
Rank Order ◽  
Growth Period ◽  
Dry Season ◽  
Tropical Environment ◽  
Wet Season ◽  
Male And Female ◽  
The Mean

The mean birthweights and weaning weights of approximately 1200 male and female calves of the F2 and F3 generations of Africander cross (AX), Brahman cross (BX) and Shorthorn X Hereford cross (SH) cattle, together with the weights at four months, and nine months post weaning for approximately 500 of the females, for the years 1964-1968, are presented. BX calves (29.7 kg) were lighter at birth than AX (31.0 kg) or SH (31.8 kg), but at weaning (eight-nine months) they were 13.7 kg heavier than the AX, and 28.9 kg heavier than the SH. In the first four months postweaning, at the end of the dry-season, female AX gained 21.5 kg, BX gained 18.5 kg, and the SH 11.7 kg, and in the next five months, which included the wet-season, AX gained 78.6 kg, BX 83.1 kg, and SH 63.2 kg. At approximately eighteen months old the AX weighed 282.8 kg, BX 294.8 kg, and SH 244.2 kg. There were substantial differences between years but the rank order of the breeds at each growth period did not change.

Evaluation of management options for increasing the productivity of tropical savanna pastures. 3. Trees

1989 ◽  
Vol 29 (5) ◽  
pp. 631 ◽  
Author(s):  
WH Winter ◽  
JJ Mott ◽  
RW McLean
Keyword(s):  
Dry Season ◽  
Perennial Grasses ◽  
Fertility Level ◽  
Wet Season ◽  
Management Options ◽  
Themeda Triandra ◽  
Weight Losses ◽  
Nitrogen Concentrations ◽  
The Mean ◽  
Stocking Rates

The effect of killing trees upon the production and quality of native perennial grasses, Themeda triandra, Chrysopogon fallax, Sehima nervosum, and Sorghum plumosum, and oversown legumes from the genus Stylosanthes, was studied over 4 years at Katherine, in the semi-arid tropics of northwestern Australia. The pastures were either unfertilised or received low inputs of superphosphate, and for each fertility level were grazed at 3 stocking rates. At no time were legume yields affected by killing the trees but, in the first 3 years, the amount of grass was approximately twice as much when the trees were killed. During this period the mean grass yields declined 4-5 fold from about 2.2 t/ha. By the fourth year the advantage from tree killing upon grass yield was apparent only at the lowest stocking rates at each fertility level. Nitrogen concentrations of the grasses and legumes, with the exception of S. hamata, were increased 7 and 10% respectively above the mean annual values of 0.89 and 1.75% where the trees were killed, while the phosphorus and sulfur concentrations were not affected. Tree killing had no effect upon wet season liveweight gains during the last 2 years of the experiment. However, there were some benefits during the dry season when weight losses were lower for most treatments during the early dry season (June-September) and also lower for the lowest stocking rate treatment without fertiliser during the late dry season (October-November).

scholarly journals Dry season and soil texture affect the chemical control of monocotyledonous in sugarcane

2018 ◽  
Vol 8 (3) ◽  
pp. 477-485
Author(s):  
Hudson Kagueyama Takano ◽  
Denis Fernando Biffe ◽  
Jamil Constantin ◽  
Rubem Silvério de Oliveira Junior ◽  
Guilherme Braga Pereira Braz ◽  
...  
Keyword(s):  
Soil Texture ◽  
Rainy Season ◽  
Clayey Soil ◽  
Dry Season ◽  
Weed Species ◽  
Wet Season ◽  
Sugarcane Crop ◽  
Dry Conditions ◽  
Loam Soil ◽  
Great Complexity

The chemical weed control in sugarcane during the wet season is more effective than the control carried out during the dry season. The objective of this study was to evaluate the efficacy of herbicides in the rainy season and in the dry season in sugarcane crop, and in different soil textural classes. The experiments simulated dry season and rainy season basing on periods of days in which experiment was submitted to irrigation restriction. In each experiment, it was tested 50 and 100% of the dose of the main herbicides commonly used in sugarcane to control B. decumbens, B. plantaginea, P. maximum and D. horizontalis. In general, in dry conditions, as well as varying the soil texture, there are restrictions in the choice of herbicide to be used due to the reduced effectiveness of some treatments in certain situations. In the very-clayey soil, especially in the dry season, the efficacy of herbicides is better, whereas, for the sandy-clay-loam soil in dry conditions, the effectiveness of herbicides is restricted. Thus, this study, despite the great complexity of the variables to be analyzed, permitted to establish guidelines for decision making on the most appropriate herbicide to be applied in each studied condition, in order to control these weed species.

scholarly journals Seasonal pattern of food habits of large herbivores in riverine alluvial grasslands of Brahmaputra floodplains, Assam

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Anita Devi ◽  
Syed Ainul Hussain ◽  
Monika Sharma ◽  
Govindan Veeraswami Gopi ◽  
Ruchi Badola
Keyword(s):  
Crude Protein ◽  
Management Practices ◽  
Feeding Habits ◽  
Seasonal Pattern ◽  
Dry Season ◽  
Imperata Cylindrica ◽  
Suitable Habitat ◽  
Wet Season ◽  
Large Herbivores ◽  
Management Interventions

AbstractJarman–Bell (1974) hypothesized that in the dry savanna of Africa, small-bodied herbivores tend to browse more on forage with high protein and low fibre content. This implies browsing on high nutritive forage by meso-herbivores, and grazing and mixed feeding on coarse forage by mega-herbivores. We tested this hypothesis in the riverine alluvial grasslands of the Kaziranga National Park (KNP), where seasonal flood and fire play an important role in shaping the vegetation structure. We analyzed the feeding habits and quality of major forage species consumed by three mega-herbivores, viz. greater one-horned rhino, Asian elephant, and Asiatic wild buffalo, and three meso-herbivores, viz. swamp deer, hog deer, and sambar. We found that both mega and meso-herbivores were grazers and mixed feeders. Overall, 25 forage plants constituted more than 70% of their diet. Among monocots, family Poaceae with Saccharum spp. (contributing > 9% of the diet), and, among dicots, family Rhamnaceae with Ziziphus jujuba (contributing > 4% of the diet) fulfilled the dietary needs. In the dry season, the concentration of crude protein, neutral detergent fibre, calcium, sodium, and phosphorous varied significantly between monocots and dicots, whereas only calcium and sodium concentrations varied significantly in the wet season. Dicots were found to be more nutritious throughout the year. Compared to the dry season, the monocots, viz. Alpinia nigra, Carex vesicaria, Cynodon dactylon, Echinochloa crus-galli, Hemarthria compressa, Imperata cylindrica, and Saccharum spp., with their significantly high crude protein, were more nutritious during the wet season. Possibly due to the availability of higher quality monocots in the wet season, both mega and meso-herbivores consume it in high proportion. We concluded that the Jarman–Bell principle does not apply to riverine alluvial grasslands as body size did not explain the interspecific dietary patterns of the mega and meso-herbivores. This can be attributed to seasonal floods, habitat and forage availability, predation risk, and management practices such as controlled burning of the grasslands. The ongoing succession and invasion processes, anthropogenic pressures, and lack of grassland conservation policy are expected to affect the availability of the principal forage and suitable habitat of large herbivores in the Brahmaputra floodplains, which necessitates wet grassland-based management interventions for the continued co-existence of large herbivores in such habitats.

scholarly journals Non-structural carbohydrates mediate seasonal water stress across Amazon forests

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Caroline Signori-Müller ◽  
Rafael S. Oliveira ◽  
Fernanda de Vasconcellos Barros ◽  
Julia Valentim Tavares ◽  
Martin Gilpin ◽  
...  
Keyword(s):  
Water Stress ◽  
Tree Species ◽  
Tree Mortality ◽  
Soluble Sugar ◽  
Dry Season ◽  
Future Climate Change ◽  
Wet Season ◽  
Dry Conditions ◽  
Almost All

AbstractNon-structural carbohydrates (NSC) are major substrates for plant metabolism and have been implicated in mediating drought-induced tree mortality. Despite their significance, NSC dynamics in tropical forests remain little studied. We present leaf and branch NSC data for 82 Amazon canopy tree species in six sites spanning a broad precipitation gradient. During the wet season, total NSC (NSCT) concentrations in both organs were remarkably similar across communities. However, NSCT and its soluble sugar (SS) and starch components varied much more across sites during the dry season. Notably, the proportion of leaf NSCT in the form of SS (SS:NSCT) increased greatly in the dry season in almost all species in the driest sites, implying an important role of SS in mediating water stress in these sites. This adjustment of leaf NSC balance was not observed in tree species less-adapted to water deficit, even under exceptionally dry conditions. Thus, leaf carbon metabolism may help to explain floristic sorting across water availability gradients in Amazonia and enable better prediction of forest responses to future climate change.

scholarly journals Nitrous oxide and methane in two tropical estuaries in a peat-dominated region of northwestern Borneo

2016 ◽  
Vol 13 (8) ◽  
pp. 2415-2428 ◽  
Author(s):  
Denise Müller ◽  
Hermann W. Bange ◽  
Thorsten Warneke ◽  
Tim Rixen ◽  
Moritz Müller ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Inorganic Nitrogen ◽  
Monsoon Season ◽  
Peat Soil ◽  
Dry Season ◽  
N2o Emissions ◽  
Wet Season ◽  
Tropical Estuaries ◽  
Ch4 Emissions ◽  
Nitrogen Concentrations

Abstract. Estuaries are sources of nitrous oxide (N2O) and methane (CH4) to the atmosphere. However, our present knowledge of N2O and CH4 emissions from estuaries in the tropics is very limited because data are scarce. In this study, we present first measurements of dissolved N2O and CH4 from two estuaries in a peat-dominated region of northwestern Borneo. Two campaigns (during the dry season in June 2013 and during the wet season in March 2014) were conducted in the estuaries of the Lupar and Saribas rivers. Median N2O concentrations ranged between 7.2 and 12.3 nmol L−1 and were higher in the marine end-member (13.0 ± 7.0 nmol L−1). CH4 concentrations were low in the coastal ocean (3.6 ± 0.2 nmol L−1) and higher in the estuaries (medians between 10.6 and 64.0 nmol L−1). The respiration of abundant organic matter and presumably anthropogenic input caused slight eutrophication, which did not lead to hypoxia or enhanced N2O concentrations, however. Generally, N2O concentrations were not related to dissolved inorganic nitrogen concentrations. Thus, the use of an emission factor for the calculation of N2O emissions from the inorganic nitrogen load leads to an overestimation of the flux from the Lupar and Saribas estuaries. N2O was negatively correlated with salinity during the dry season, which suggests a riverine source. In contrast, N2O concentrations during the wet season were not correlated with salinity but locally enhanced within the estuaries, implying that there were additional estuarine sources during the wet (i.e., monsoon) season. Estuarine CH4 distributions were not driven by freshwater input but rather by tidal variations. Both N2O and CH4 concentrations were more variable during the wet season. We infer that the wet season dominates the variability of the N2O and CH4 concentrations and subsequent emissions from tropical estuaries. Thus, we speculate that any changes in the Southeast Asian monsoon system will lead to changes in the N2O and CH4 emissions from these systems. We also suggest that the ongoing cultivation of peat soil in Borneo is likely to increase N2O emissions from these estuaries, while the effect on CH4 remains uncertain.

scholarly journals River Discharge and Water Level Changes in the Mekong River: Droughts in an Era of Mega-Dams

2021 ◽  
Author(s):  
XiXi Lu ◽  
Samuel Chua
Keyword(s):  
Water Level ◽  
Water Discharge ◽  
Dry Season ◽  
Water Levels ◽  
Mekong River ◽  
Wet Season ◽  
Discharge Data ◽  
Mekong Basin ◽  
Lower Mekong Basin ◽  
Dry Conditions

While 1992 marked the first major dam – Manwan – on the main stem of the Mekong River, the post-2010 era has seen the construction and operationalisation of mega dams such as Xiaowan (started operations in 2010) and Nuozhadu (started operations in 2014) that were much larger than any dams built before. The scale of these projects implies that their operations will likely have significant ecological and hydrological impacts from the Upper Mekong Basin to the Vietnamese Delta and beyond. Historical water level and water discharge data from 1960 to 2020 were analysed to examine the changes to streamflow conditions across three time periods: 1960-1991 (pre-dam), 1992-2009 (growth) and 2010-2020 (mega-dam). At Chiang Saen, the nearest station to the China border, monthly water discharge in the mega-dam period has increased by up to 98% during the dry season and decreased up as much as -35% during the wet season when compared to pre-dam records. Similarly, monthly water levels also rose by up to +1.16m during the dry season and dropped by up to -1.55m during the wet season. This pattern of hydrological alterations is observed further downstream to at least Stung Treng (Cambodia) in our study, showing that Mekong streamflow characteristics have shifted substantially in the post-2010 era. In light of such changes, the 2019-2020 drought – the most severe one in the recent history in the Lower Mekong Basin – was a consequent of constructed dams reducing the amount of water during the wet season. This reduction of water was exacerbated by the decreased monsoon precipitation in 2019. Concurrently, the untimely operationalisation of the newly opened Xayaburi dam in Laos coincided with the peak of the 2019-2020 drought and could have aggravated the dry conditions downstream. Thus, the mega-dam era (post-2010) may signal the start of a new normal of wet-season droughts.

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