• Journal of Ecology and Environment
• /
• v.31 no.4
• /
• pp.297-307
• /
• 2008

In order to assess the effect of grazing on grasslands using floristic composition, we studied the floristic composition and plant biomass of steppe vegetation in Hulunbeier, Inner Mongolia. The dominant species of the grasslands were Stipa krylovii, Stipa grandis and Leymus chinensis. Floristic composition changed according to grazing pressure, being light, heavy and moderate. Under heavy grazing conditions, the importance value of P. acaulis, C. korshinskyi and Cleistogenes squarrosa increased in the plant community. These species were indicators of heavily grazed stand. Plant biomass of the stands ranged within 11.6g $m^{-2}$ and 63.5g $m^{-2}$ and 69.5g $m^{-2}$ and 166.2g $m^{-2}$ to the west and east of Lake Hulun, respectively. These values are equivalent to ca. $450{\sim}1,000kg$ of atmospheric carbon per hector, which is retained within the stand during the summer season.

• Proceedings of the Korean Society of Grassland Science Conference
• /
• 2005.06a
• /
• pp.202-203
• /
• 2005

• Asian-Australasian Journal of Animal Sciences
• /
• v.26 no.12
• /
• pp.1717-1725
• /
• 2013

The objectives of this study were to compare visual observation and an electronic grazing time method and to evaluate the effects of nutritional plans on intake, grazing behavior and horizontal and vertical locomotion of young bulls in a tropical pasture. Thirty-nine Nellore young bulls with an average body weight of $345{\pm}9.3$ kg kept in pasture were used. The experimental treatments consisted of: restricted: animals kept in a plot with a low mass of forage receiving mineral mixture only; control: animals receiving mineral mixture only; HPHC: a high protein and high carbohydrate supplement; HPLC: a high protein and low carbohydrate supplement; LPHC: a low protein and high carbohydrate supplement; LPLC: a low protein and low carbohydrate supplement. GPS collars equipped with activity sensors were used. Information about head position, latitude, longitude and altitude were recorded. Daytime grazing behavioral patterns monitored by a continuous focal animal recording method was compared to behavior estimated by the activity sensor. Feed intake was estimated by a marker method. The Restricted group presented lower (p<0.05) intake of dry matter and TDN. However, difference in dry matter intake was not found (p>0.05) between non-supplemented and supplemented animals. Difference was not found (p>0.05) in daytime grazing time obtained by visual observation or the activity sensor method. The restricted group showed longer (p<0.05) grazing time (9.58 h/d) than other groups, but difference was not found (p>0.05) in the grazing time between Control (8.35 h/d) and supplemented animals (8.03 h/d). The Restricted group presented lower (p<0.05) horizontal locomotion distance (2,168 m/d) in comparison to other groups (2,580.6 m/d). It can be concluded that the use of activity sensor methods can be recommended due to their being similar to visual observation and able to record 24-h/d. While supplements with high carbohydrates reduce pasture intake, they do not change grazing behavior. Moderate supplementation (until 50% of protein requirement and 30% of energy requirement) of beef cattle on tropical pasture has no effect on daily locomotion.

• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.2
• /
• pp.189-197
• /
• 2003

Soluble glass bolus with selenium (Se), copper (Cu) and cobalt (Co) was administered intraruminally to Philippine grazing does fed under backyard farming conditions to determine its effect on blood mineral status. Forty-five does were dosed with SGB intraruminally every 6 months, whereas 15 were without SGB during this experimental period of 10 months. Blood of does in both treatment groups were collected every other month and blood Se, plasma Cu, Ca, P and Mg were determined in this study. All does did not show clinical Se, Cu, Ca, P or Mg deficiency during this experimental period. Selenium concentration of treated does increased (p<0.01) after beginning of this experiment, whereas the level of control does decreased slowly (p<0.01). Two months after SGB administration, all treated does had higher blood Se than the lower limit of $20{\mu}g/l$ suggested by NRC (1981), whereas some control does had lower blood Se concentration than the lower limit of $20{\mu}g/l$. On the other hand, plasma Cu concentration of treated does started to increase more remarkably than control does 4 months after this experiment had started although the difference was insignificant. There were no significant differences between plasma Ca, P or Mg concentration of does in both treatment groups. Soluble glass bolus had no harmful effects on plasma macro mineral concentrations of grazing does. This study showed that SGB was available as mineral supplement to improve imbalances of selected mineral of grazing goats in the traditional backyard conditions in Luzon Island, Philippines.

• Proceedings of the National Institute of Ecology of the Republic of Korea
• /
• v.1 no.1
• /
• pp.22-30
• /
• 2020

Many areas of vegetation in the British uplands have reduced species diversity as a result of sheep overgrazing. It has been suggested that abandonment or re-wilding strategies might be used to reverse this. A likely first step would be the removal or reduction of grazing livestock from upland areas, with a presumption that this would lead to a recovery in species richness. However, we do not know if this would work, or the timescales involved. One of the important areas where more knowledge is needed is information on the size and composition of soil seedbanks as regeneration from zseed is a likely pathway of recovery. Here, we compared seedbanks in both grazed and ungrazed plots in five experiments at Moor House NNR in the northern Pennines; these sheep grazing exclusion experiments were started 52 and 63/64 years ago. Soil samples (n=10) were collected from both grazed and ungrazed plots in each experiment, and seed emergence counted in glasshouse trials. We detected only seeds of common species and very few dicotyledonous species. This suggests that the soil seedbank is unlikely to be a reliable source of the less common species for ecological restoration in these upland communities, suggesting an extinction debt. Therefore, seed addition and the creation of suitable safe-sites for germination may be needed in conjunction with grazing controls to allow the establishment of plants that will increase the species richness of the vegetation. However, this interventionist restoration approach remains to be tested.

• Animal Bioscience
• /
• v.36 no.11
• /
• pp.1655-1665
• /
• 2023

Objective: The aim of this study was to evaluate the effects of three feeding systems, i.e., indoor feeding (CON), indoor feeding with 4-h daily access to grazing artificial pasture (ITGP), and indoor feeding with 8-h daily access to grazing artificial pasture (IEGP), on the plasma antioxidant and immunological capacity, slaughter characteristics, meat quality and economic efficiency of Huang-huai lambs. Methods: Thirty-three healthy Huang-huai rams with similar body weight (approximately 5 mo of age, 28.96±1.01 kg) were assigned equally to three experimental groups. When finished fattening, six lambs from each group were collect blood samples for plasma analyses and then slaughtered to determine slaughter characteristics and obtain biceps brachii muscle for further analysis of meat quality and fatty acid profile. Results: Compared to CON group, animals submitted to ITGP and IEGP groups resulted in greater contents of serum glutathione peroxidase, immunoglobulins (IgA, IgG, and IgM), polyunsaturated fatty acids (PUFA), n-6 PUFA, and PUFA/saturated fatty acid (FA) ratio and lower palmitic /oleic acid ratio (p<0.05). Moreover, animals in ITGP group exhibited a higher (p<0.05) loin eye area, content of meat crude protein (CP), and eicosetrienoic acid compared to CON group, while slaughter performance was superior (p<0.05) to that of the IEGP group. The economic efficiency of ITGP group was 70.12% higher than that of CON group, while the IEGP group exhibited a decrease of 92.54% in economic efficiency compared to the CON group. Conclusion: Restricted grazing time combined with indoor feeding was more effective in conferring superior body health, carcass traits and economic efficiency in Huang-huai lambs, as well as higher CP content and healthier FA composition in the resulting meat.

• Korean Journal of Microbiology
• /
• v.29 no.6
• /
• pp.371-379
• /
• 1991

Effects of freshwater red tide of Peridinium bipes (dinoflagellate) in August of 1991 on the carbon flux through the microbial loop were studied in Soyang Reservoir. Chlorophyll a and primary production, bacterial production in red tide area were 22, 18 and 400 times higher, respectively, than other sites. Phytoplandton biomass comprised 97% and 20% of food source of zooplankton grazing within and without red tide, respectively. The percent bacterial production supported by phytoplankton exudate was 14% within red tide and >100% without red tide. In laboratory experiments, more than 85% organic carbon of Peridinium biomass was released or degraded by heterotrophic bacteria within 14 days. As results of red tide of Peridinium with sudden influx of organic carbon in water column, the main food source of zooplankton and dependency of bacteria on phytoplankton exudate were changed. Therefore, the relative importance of microbial loop to grazing food web was changed.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.13 no.1
• /
• pp.43-48
• /
• 1993

This experiment was carried out to determine the effects of application time of cattle slurry on grazing pasture on the grass growth, dry matter yield, nutritive value, animal preference, and efficiency of pasture utilization. Four different application times of slurry(right now after grazing, 5th day, 10th day, and 15th day after grazing), and a no-slurry(control) plot were designed, 1991∼1992. Annual application amount of slurry was 40 ㎥/ha, and slurry was applicated in spring(2 times), summer and autumn. Total NPK fertilizer applicated were same as 280, 200 and 240 kg/ha in all treatment, respectively. The pasture was grazed with growing beef cattle(initial body wt.; ca. 250 kg) at every 30∼35 cm of plant height. The grass height, dry matter yield, crude protein yield, and other nutritive value were not different among treatments. However, the animal preference and efficiency of pasture utilization showed significant difference by application time of slurry. The highest grazing preference (1: the worst∼9: the best). and utilization efficiency (0∼100%) were observed by application time of right now after grazing (7.8, 76%), which was same to control(7.8, 77%), and followed by 5th day after grazing(7.3, 74%) and l0th day after grazing(6.9, 71%). But the preference and pasture utilization were greatly decreased at application time of cattle slurry of 15th day alter grazing(5.5, 60%). From the above results, the optimum application time of cattle slurry on grazing pasture to enhance animal preference, and efficiency of pasture utilization was within 5 days after grazing (less than 13.6 cm of plant height), and within 10 days after grazing (less than 18.5 cm of plant height) at least.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.12 no.3
• /
• pp.125-132
• /
• 2007

We estimated the distribution of predator-prey interaction strengths for 12 species of herbivores (including amphipods, isopods, gastropods, and sea urchins) and made a regression model that may be applicable to other species. Laboratory experiments were used to determine per capita grazing rate (PCGR; g seaweeds/individual/day). Relationship between the biomass of individual grazers and fourth-root transformed PCGR was fitted to power curve ($y=0.2310x^{0.3290}$, r=0.8864). This finding supported that the grazing efficiency was not even as individual grazers increase in size (biomass). Therefore, the biomass-normalized PCGR was estimated and revealed that smaller size herbivores were more effective grazers. Grazing impact considering density of each taxon was calculated. The sea hare Aplysia kurodai had greatest grazing impact on the seaweed bed and the sea urchin Strongylocentrotus nudus and S. intermedius were ranked in descending order of the impact. The amount of seaweed grazed by the amphipod Elasmopus sp. (>4,000 $ind./m^2$) and Jassa falcata (>2,000 $ind./m^2$) were 3.435 and $1.697mg/m^2/day$ respectively. The combined grazing amount of herbivores was $5,045mg/m^2/day$ in the seaweed bed. Although sea hare and sea urchin had strong impacts on seaweeds, the effects of dense, smaller species could not be seen as negligible. Surprisingly, the calculated grazing potential of sea urchins with a mean density of 3 $ind./m^2$ exceeded the mean production of seaweed cultured in domestic coastal waters in Korea (ca., 5 ton/ha). Small crustaceans were also expected to consume up to 16% of the seaweed production if their densities were rising under weak predation conditions. Considering that the population density of herbivores are strongly controlled by fish, human interference like overfishing may have strong negative effects on persistence of seaweeds communities.

• Asian-Australasian Journal of Animal Sciences
• /
• v.13 no.6
• /
• pp.837-841
• /
• 2000

The study was conducted at semi urban area in Bangladesh. It was based on a field survey by a prepared questionnaire. Various milking and reproduction performance were analyzed. The effects of grazing hour were found significant on age at weaning (AW) (p<0.001), age at first heat (AFH) (p<0.001), age at first conception (AF conception) (p<0.001), age at first calving (AF calving) (p<0.001), post partum heat period (PPHP) (p<0.001), calving interval (CI) (p<0.001), lactation length (LL) (p<0.001) and total lactational production (TLP) (p<0.001). The effects of concentrate feed were significant on AW (p<0.01), AFH (p<0.01), AF conception (p<0.001), AF calving (p<0.001), PPHP (p<0.001) CI (p<0.001), LL (p<0.001) and TLP (p<0.001). The effects of management level were significant on AW (p<0.001), PPHP (p<0.01), CI (p<0.001), daily milk yield (DMY) (p<0.05) and TLP (p<0.001). The overall mean values were $251.88{\pm}2.97$ days for AW, $37.29{\pm}0.33$ months for AFH, $38.43{\pm}0.34$ months for AF conception, $47.62{\pm}0.34$ months for AF calving, $1.30{\pm}0.02$ number of services per conception (NSPC), $191.57{\pm}3.92$ days for PPHP, $17.02{\pm}0.15$ months for CI, $2.49{\pm}0.06kg$ for DMY, $247.23{\pm}3.51$ days for LL and $590.40{\pm}15.00kg$ for TLP.