• Journal of Ecology and Environment
• /
• v.34 no.3
• /
• pp.295-305
• /
• 2011

Many studies have suggested the positive effects of grazing by large herbivorous mammals on seed dispersal, but little is known about how herbivores could affect the fate of ingested seeds. This study examined the effects of seed ingestion by sika deer (Cervus nippon) on seed fate in a temperate grassland established in an urban park long resided by high densities of sika deer. I compared species composition and seasonal traits of seed abundance and maturity in the grassland community with those in deer fecal pellets. In total, 27 herbaceous species were observed, including the predominant Zoysia japonica. Seed phenology and production differed among the three dominant species (Z. japonica, Digitaria violascens, and Hydrocotyle maritima). Pellets contained at least 26 species of herbaceous seeds, and their abundance differed among species. Of the 26 species, 15 were observed in the vegetation at the study site. The peak of seed abundance in pellets for the dominant species appeared 1 month after the peak of inflorescence production (but most of the inflorescences were immature and susceptible to digestion) and consequently corresponded to the peak of mature inflorescence. Because sika deer are likely to ingest seeds at any maturity stage in the grassland and immature seeds are less hardened, ingested immature seeds can suffer great losses. The results suggested that the survival of germable seeds with great losses of immature seeds may be a factor determining which plant species can be successfully dispersed by herbivores.

• ALGAE
• /
• v.27 no.1
• /
• pp.9-19
• /
• 2012

Phlorotannins are common metabolites produced in kelps that can have deterrent functions against grazers. The factors dictating seasonal patterns of phlorotannin content in northeastern Pacific kelps are not well understood. This study assessed density and grazing of the gastropod Lacuna vincta on the annual canopy-forming kelp Nereocystis luetkeana and the perennial understory species Agarum clathratum, Saccharina latissima and S. groenlandica in Kachemak Bay, Alaska. In addition, we assessed seasonal patterns of environmental variables as possible drivers of phlorotannin concentrations. Phlorotannins occurred in all species, with overall lowest levels in N. luetkeana, and with different seasonal patterns among the four species. Lacuna vincta was most dense on N. luetkeana thalli in the summer and had highest grazing rates on this low-phlorotannin species. However, correlations between L. vincta density and phlorotannin content of each kelp species were not significant. Except for N. luetkeana, there were no correlations between phlorotannin levels and environmental variables. We suggest that kelp life history traits may be more important for phlorotannin patterns in these kelp species than grazers or environmental drivers.

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.1
• /
• pp.18-26
• /
• 2004

This study evaluated the impact of an AI heifer calf rearing scheme on dairy stock development, in a coconut grazing and a peri-urban smallholder dairy production system in the Western Province of Sri Lanka. The heifer rearing scheme included free advice on calf rearing, drugs, acaricides, minerals and subsidised concentrates for 30 months. The farmers in the coconut growing area integrate dairying with their plantation, they sell their milk to the main processors. The peri-urban farmers are intensive milk producers, who sell their milk at informal markets. To estimate the effect of the heifer rearing scheme on dairy replacement stock development, scheme farmers were compared with farmers who did not participate in the scheme. Calf mortality was twice as high in non-scheme farms (23-28%) as in scheme farms (12-14%). The scheme had a positive effect on weight development and scheme heifers calved 4.5 months earlier than non-scheme heifers. The calf rearing package is cost effective in both farming systems, however, the required cash inputs are a major constraint. The costs per in-calf heifer under the scheme are much lower than the production of such animals by either multiplication in state farms or importing them. The coconut grazing system showed the highest potential for producing surplus dairy stock.

• Asian-Australasian Journal of Animal Sciences
• /
• v.10 no.5
• /
• pp.484-490
• /
• 1997

Spatial distribution of urination by Japanese Black heifers and steers was investigated, and compared with the distribution of defecation. The animals grazed a bahiagrass (Paspalum notatum $Fl\ddot{u}gge$) pasture in the daytime, and spent the rest of the day in a barn. The distribution of urination to the pasture was greater than that expected from the proportion of time that the animals spent in the pasture. Correspondingly, the distribution was smaller in the barn. Such a distribution pattern of urination to the pasture and barn was similar to that of defecation, and affected by the intake of supplement on the previous day. The distribution of urination within the pasture, i.e. the distribution to the paddock, alley and resting area, was often uneven on an area basis. The animals often urinated sparsely in the alley and resting area, while they urinated in the paddock almost proportionally to its area. This was a clear contrast to the distribution pattern of defecation, which was sparse in the paddock and dense in the resting area. The degree of aggregation of urination in the paddock, alley and resting area varied with the meteorological factors and the intake of supplement.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.11
• /
• pp.5206-5210
• /
• 2012

We studied the effect of food concentration on grazing, growth and fecundity of cyclopoid copepod Paracyclopina nana. Marine phytoplankton Tetraselmis suecica was used as a livefood for the copepod. Six stage compositions were used and food concentrations for the experiment were 0.5, 1, 2, 5, 10, 20, 40, 60 and $80{\times}10^4$ cells/mL. Range of food concentrations with 0.2, 0.5, 1, 2, 3 and $4{\times}10^4$ cells/mL were used for nauplii production experiment. Grazing rates of P. nana in all developmental stages on the different concentrations were increased with increasing diet concentration. While the growth of nauplius was not affected by increase of food concentration, food concentration outside of $1{\times}10^4$ to $5{\times}10^4$ cells/mL range negatively affected that of copepodite. Daily nauplii production was increased with increasing food concentration but $3{\times}10^4$ and $4{\times}10^4$ cells/mL treatments were not significantly different with $2{\times}10^4$ cells/mL treatment. As a result, optimum concentration of T. suecica for mass culture of P. nana was considered to be 5,000 cells/mL for nauplius stage, 10,000 cells/mL for copepodite stage and adult male, 20,000 cells/mL for adult female, respectively.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.6
• /
• pp.908-913
• /
• 2007

Concentrations of major elements in forages were determined in relation to ruminant requirements at a livestock experimental station in Leiah district, Punjab-Pakistan using mapping techniques. The study investigated the influence of sampling periods and pasture types on the concentrations of calcium, magnesium, potassium, and sodium in forages. The implications of these forages for nutrition of ruminants were assessed for the livestock population at that particular experimental station, which are supported by the farm pastures. Within the farm, variations in the element status of the forages were related to soil pasture types. A tentative assessment of the mineral status of available forages at this farm for different pastures using guidelines developed for domestic animals indicated deficiencies of only Na, but forages contained adequate Ca, Mg, and K levels required for grazing ruminants. The concentrations of Na in the forage reserves indicated that the potential supply of this element to plants was limited from the soil to plants and from plants to the animals grazing them. Soil minerals were not measured in this study. The potential use of fertilizers, as pasture amendment as well as supplementation of ruminants, with a specifically tailored mineral mixture is important to livestock producers and environmentalists as well, because their use may improve forage nutritive value and in turn meet requirements of animals.

• Korean Journal of Veterinary Service
• /
• v.18 no.3
• /
• pp.42-52
• /
• 1995

Anaplasmosis is most important tick-borne rickettsial diseases of domestic ruminant. with Anaptasma spp. as their respective causal agents. In order to the survey prevalence of anaplasmosis in Korean native goats, we examined the Giemsa's blood filrms from 552 grazing and 188 nongrazing-goats in Chonbuk area Namwon, Imsil and Sunchang. The conclusive diagnosis was made by observing the characteristic marginal or central bodies in the red blood cells. The infection rate of grazine and nongrazing-goats with Anaplasma spp. was 71.7% and 8.5%, respectively. In order to study about the therapeutic effects of drug for 40 grazing-oats infected with Anaptasma spp. in mountain-area, Berenil(diminazene acetate) was jntramuscularly injected (0.5㎖ /10kg B.W.). After 1 month, we don't detected the parasite in the blood films from 33 goats(82.5%), but no change of significant hematological values(PCV, ESR, WBC, RBC, MCH, MCHC, PLT, MPV, PDW and HB) was observed. These results indicated that the infection rate of Anaplasma spp. was higher on glazing than nongrazing-goats and Berenil as an antianaplasmal drug is recommended.

• Journal of Korean Society of Forest Science
• /
• v.74 no.1
• /
• pp.10-15
• /
• 1986

Pasture in woodland have been extensively established to meet the demand of forage for livestock. The survey type of study was conducted to investigate and analyze for the establishment of pasture in woodland from foresters' standpoint. The findings can be provided for basic data to achieve appropriate wooldland use pattern. The study area was confined to Pyungchang county, Hoengsung county, and Hongcheoa county, which are primary pasturing region in Kangweon province. The analysis was based on the field survey of 30 pastures (grouped to 'successful', 'failed', and 'grazing-in-the-wood' site) and returned 133 questionnaires from 398 debriefed pasture owners.

• Journal of Korean Society on Water Environment
• /
• v.27 no.6
• /
• pp.776-783
• /
• 2011

In a natural water body, a useful ecotechnology to reduce standing crops of phytoplankton is to strengthen the top-down force of zooplankton. However, the predation of fish for zooplankton can make the force weak. This study was conducted to find out the effect of fish on the grazing pressure of zooplankton in the mesocosms established in a eutrophic stream (Kyongan Stream) from October to November in 2010. In the corral with fish, chlorophyll a concentration increased, and a small size cladoceran Bosmina longirostris was dominant. In the corral without fish, chlorophyll a concentration decreased along with the domination of a large cladoceran Daphnia galeata and a large copepod Eudiaptomus japonicus. The size-selective predation of fish appeared to miniaturize the zooplankton community, to narrow their food-size spectrum, and to weaken the top-down force.

• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.1
• /
• pp.61-67
• /
• 2010

The chemical components in plant cuticular wax can be used as markers to estimate the species composition of the diet of grazing animals. In this experiment, composition of the diet of yak on the Qinghai-Tibetan plateau was estimated using n-alkane analysis. During the grazing period, samples of whole plants of the species present, plus fecal samples voided by the yak, were collected, air-dried and ground prior to the extraction of cuticular wax n-alkanes. The species composition of the yak diets was estimated by relating fecal alkane contents to those of the plant species, using the 'ATWHAT'software package. The results showed that the n-alkane technique can detect the main dietary components selected by yak. The diet consumed by yak contained 33% Kobresia humilis, 67% Stipa aliena in summer pasture; 26% Potentilla anserine, 74% Carex qinghaiensis in autumn pasture; 52% Carex qinghaiensis, 32% Heteropappus bowerii and 16% Saussurea semifasciata in winter pasture and 5% Carex qinghaiensis, 95% Achnatherum splendens in spring pasture. The apparent selection for forbs is likely to be a reason for nutritional constraint of yak inhabiting alpine environments.