• Asian-Australasian Journal of Animal Sciences
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• v.21 no.10
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• pp.1466-1472
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• 2008

Variations in conjugated linoleic acid (CLA) concentrations in Holstein dairy cows milk, depending on feeding systems in different seasons was investigated. Milk samples were collected from Holstein dairy cows, which either grazed for whole days (WG), only daylight hours (TG), or were offered a total mixed ration (TMR) and experienced no grazing (NG), from April to December of 2005. In April, November and December, the cows in TG and WG treatments received grass silage and some concentrate, while from May to October, the cows grazed on temperate pasture. The cows in NG treatment received the TMR throughout the season. The major fatty acid obtained in the pastures was linolenic acid. There was no significant difference in the pasture's linolenic acid concentrations from May to September, but there was a significant decrease in October. However, the linolenic acid concentrations obtained in the pasture were always much higher than those obtained from the TMR. Linoleic acid was also the major fatty acid in the TMR, but these concentrations were higher in the TMR than in the pasture. There was no significant difference in milk cis9trans11CLA (c9t11CLA) concentrations between the three feeding systems while the cows were fed on conserved pasture in April, November and December. Although c9t11CLA concentrations were lower in the TMR, it was found that the cows which grazed in fresh pasture experienced significantly higher concentrations of c9t11CLA in their milk than those which received only TMR. It was also found that cows in the WG treatment experienced higher c9t11CLA concentrations than those in the TG treatment. In the WG and TG treatments, c9t11CLA concentrations were highest in June, after which, they gradually decreased (p<0.01) until October. For the NG treatment, there was no significant change in the concentrations of c9t11CLA (p>0.05) with season. Overall, trans11C18:1 and c9t11CLA were greatly influenced by season, with higher variation in the WG treatment than in the TG treatment and no variation in the NG treatment.

• Korean Journal of Ecology and Environment
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• v.36 no.3 s.104
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• pp.286-294
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• 2003

This study was attempted to understand seasonal dynamics of phyto- and zooplankton communities in shallow, eutrophic Lake llgam and to compare them with the PEG (Plankton Ecology Group) model. Seasonal succession pattern of phytoplankton community was similar to PEG model as Chlorophyceae and Baciliphyceae increase during spring and autumn fellowed by increase of Cyanophyceae. However, based on the cell density and biomass, a dominant phytoplankton community differed with PEG model: Cyanophyceae had been a dominant community throughout a year, except for ice-cover period during which Chlorophyceae was a dominant group. In spring, when ice melted and dissolved nutrients in water column increased, the increase of Chlorophyceae occurred: when nutrients (DIN and DIP) rapidly decreased, Cyanophyceae increase occurred. Microcystis, Oscillatoria, Lyngbya, Merismopedia were maior dominant species of Cyanophyceae and their cell density and/or biomass was the highest in October 2000 (12.9${\pm}$5.8${\times}10^5$ cells/ml, 3.5${\pm}$0.9${\times}10^3{\mu}gC/l$). Cyanophyceae biomass showed positive relationship with chlorophyll a ($r^2$ = 0.71,P< 0.001) and TP concentration ($r^2$ = 0.62, P< 0.001). Small-sized rotifers such as Keratella cochlearis, increased between March and May when Chlorophyceae increased. Both high standing crop of copepods and cladocerans, such as Diaphanosoma brachyrum and Bosmina longirostris occurred between June and September accompanied with the increase of Dinophyceae and Bacillariophyceae. There was no evidence that clear-water phase was caused by zooplankton grazing. The diversity and evenness index of phyto- and/or zooplankton increased with chlorophyll a concentration. These results suggest zooplankton grazing and limiting nutrient deficiency could lead to change of phytoplankton biomass, but not the phytoplankton community in Lake llgam.

• Journal of The Korean Society of Grassland and Forage Science
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• v.12 no.3
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• pp.30-40
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• 1992

The area of grassland established and the arable land in forage production have been decreased recently in Korea. As a result, forages available from the grassland and the arable land provided only 40% of the total roughage consumed by cattle in 1991, compared with 54% in 1989. The decreasing trend of the forage production has been impinged on by a number of legislative. socio-economic. technical and other constraints negatively affecting grassland and forage development. Consequently. effective systems and strategies are quite necessary to have sustainable grassland farming in Korea. In spring and autumn, temperatures are too low for subtropical forage crops, and the summer monsoon climate is another serious limitation to the use of cool-season species. Therefore it is an imperative that not only the research-based grassland development but also the forage crop production should be strongly supported by the government authorities to overcome such climatic limitations. Private forest land holdings are of relatively small units in Korea. Accordingly. it is necessary and important to enlarge the forest land holdings per farm to develop as economic units of grassland. For this the government should introduce new policy measures such as for example: long-term leases of Sorest land and the idle arable land of absentee owners ; rational rental system of national and public forest lands; integrating livestock and forest production. All the laws and regulations standing in the way of the grassland development in forest lands should be modified and revised to open the way for much easier development of grassland. It is also proposed that a high level of financial incentives -hould be provided for structural improvements for the grassland development. They may be: mechanization facilitation, construction of new roads relating to grassland, and land exchange and consolidation. And it is basically necessary that financial enumeration or profits must be garanteed in order to motivate farmers to keep up farming continuously. For more efficient grassland development in mountainous areas, reorganization of Alpine Experiment Station and NAB1 Namwon Branch Station may be needed. Research should be strengthened for completion of pasture mixtures, development of maximum forage production methods with a view to saving labor and reducing production costs, introduction of grazing and forage conservation techniques. and utilization of rice straw as more palatable and nutritious forage source. In order to have more efficient and effective transfer of advanced forage production technologies to livestock farmers the user-clients. it is also essential that special training measures should be given to livestock farmers through making greater use of specialized research and extension workers.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.8
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• pp.1140-1150
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• 2009

Forage diets provide good quality carcasses in sheep but very little is known in tropical goats. An experiment was designed with Creole male goats using grass-based systems to assess carcass yield, scores, cuts and composition. After weaning (84 d, 9.2 kg LW) two modes of forage feeding were compared with two replicates of each. Feeding groups were: PF for animals reared at pasture (n = 62) and IF when reared indoors (n = 60). Given that forage finishing will result in low ADG it appeared necessary to study different fattening lengths. The kids were equally divided into 4 groups: group A (n = 32), 4mo after weaning; group B (n = 32), 4mo after A; group C (n = 30), 3mo after B and group D (n = 28), 2mo after C. The animals grazed (in two sub-flocks) on irrigated tropical pastures managed in a rotational system (28 d of re-growth) at a mean stocking rate of 1,200 kg/ha/yr LW. The IF groups were reared in collective pens on a slatted floor (2 replicates of 7 or 8 kids each). They were fed the same stand of tropical grass (25% DM, 12% CP) as that of pasture that was cut daily and provided ad libitum. The ADG (-10%), the weights of omental fat (-60%) and fat in shoulder (-18%), the ultimate pH of carcass (-12%), the meat colour score (-24%), the ""parameter accounting for redness (12%) and the DM and lipid contents (-4%) were significantly lower (p<0.05) in PF than in IF, while the liver was heavier (+23%, p<0.05). Feeding conditions seemed to be similar, thus, differences could be related to gastrointestinal parasitism in the PF system and hypotheses are discussed. Increasing the fattening duration, resulted in significant difference (p<0.01) in many traits: the weights at slaughter and of carcass increased by 40% and 60% from groups A to D and consequently the weights of body compartments and carcass cuts (1.5 to 2.0 fold more). When the results were presented as percentage of empty body weight and carcass weight, these preliminary results (carcass weight 9kg and yield 53%, muscle proportion 70%) and qualitative parameters (low fat score 2/5, fat proportion 5%), seem to be a good incentive for the sector to develop a niche market to meet consumer lean meat expectations. The indoors system could be implemented where there was low availability of grazing areas or problems of dog attacks.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.7
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• pp.1005-1015
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• 2009

Two experiments were carried out to determine the utility of sainfoin hay, a temperate tanniferous forage legume, as a dietary supplement for grass-fed cows. The condensed tannins (CT) of sainfoin might counteract the typical metabolic ammonia load of cows in intensive grazing systems. Furthermore, the physical fibrousness of sainfoin might improve ruminal pH stability. In the preliminary experiment, the eating rate of non-lactating Holstein cows of two tanniferous hays, sainfoin and birdsfoot trefoil, was compared to that of a grass-clover hay after specific periods of time (n = 4). The eating rate of sainfoin was superior to that of the other forages. In the main experiment, designed as a replicated 3${\times}$3 Latin square, six ruminally-cannulated, lactating Red Holstein cows received grass, concentrate and either no supplementation, 3 kg/d of grass hay or 3 kg/d of sainfoin hay (n = 6). Measured intakes of the grass hay and the sainfoin hay were 2.0 and 1.5 kg DM, and two cows entirely refused to eat the sainfoin hay and had to be excluded from data analysis. Grass DMI was similar for cows supplemented with sainfoin hay and cows fed only grass whereas intake of concentrate was higher (p<0.01) for the latter treatment. Continuous measurement of ruminal pH showed that the minimum pH at night tended to be lower (p<0.10) with grass-only feeding compared to sainfoin supplementation, but pH did not decline below the threshold of subacute acidosis for a longer period of time. The slightly higher intake of nitrogen (N) for cows supplemented with sainfoin hay (413 g/d) compared to cows fed only grass (399 g/d) was accompanied by an increased (p<0.05) fecal N excretion and a tendency for an increased (p<0.10) urinary N excretion. Ruminal ammonia concentration, as well as plasma and milk urea, were not affected by sainfoin supplementation. In conclusion, the lack of positive effects typical for CT might be explained either by the limited CT content of this plant species (55 g/kg DM) or the relatively low proportion of sainfoin in the total diet or both. Moreover, due to the unexpected low grass quality, the general ammonia load might have been too low for CT to have an impact.

• Korean Journal of Organic Agriculture
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• v.20 no.2
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• pp.185-200
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• 2012

It has been reported that world population continues to increase so that a matter of food security can be a world-wide problem for mankind. An anticipated rise in world population of 30% and the subsequent increased demand for food brings with it challenges in terms of global resource usage and food security. However, ruminant livestock production and consumption make a large contribution to the greenhouse gas (GHG) emissions which can be attributable to food production. Given the association between GHG and climate change, this is clearly of great concern to the livestock industry worldwide. Nevertheless, ruminant livestock also play an important role in global food security as they can convert the plant cell wall materials and non-protein nitrogen compounds, found widely in plants but indigestible to all monogastric animals including man, into high value proteins for human consumption. Much effort has been made to maximize animal production, feed conversion ratio, and to improve animal breeding in ruminant agriculture. In addition improving feed formulation techniques, developing chemical additives, plant extracts, and new plant varieties for grazing have been tested. Future ruminant production systems will need to capitalize on important benefits of ruminants. It is therefore suggested that ruminant agriculture has a key role to play in maintaining and enhancing provision of quality proteins and essential nutrients for human being but the challenge of reducing GHG emissions, and methane in particular, needs to be successfully addressed.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.7
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• pp.1054-1060
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• 2017

Objective: This study was aimed at evaluating effects of cattle breed resources and alternative mixed-feeding practices on meat productivity and emission intensities from household farming systems (HFS) in Daklak Province, Vietnam. Methods: Records from Local $Yellow{\time}Red$ Sindhi (Bos indicus; Lai Sind) and 1/2 Limousin, 1/2 Drought Master, and 1/2 Red Angus cattle during the growth (0 to 21 months) and fattening (22 to 25 months) periods were used to better understand variations on meat productivity and enteric methane emissions. Parameters were determined by the ruminant model. Four scenarios were developed: (HFS1) grazing from birth to slaughter on native grasses for approximately 10 h plus 1.5 kg dry matter/d (0.8% live weight [LW]) of a mixture of guinea grass (19%), cassava (43%) powder, cotton (23%) seed, and rice (15%) straw; (HFS2) growth period fed with elephant grass (1% of LW) plus supplementation (1.5% of LW) of rice bran (36%), maize (33%), and cassava (31%) meals; and HFS3 and HFS4 computed elephant grass, but concentrate supplementation reaching 2% and 1% of LW, respectively. Results: Results show that compared to HFS1, emissions ($72.3{\pm}0.96kg\;CH_4/animal/life$; least squares $means{\pm}standard$ error of the mean) were 15%, 6%, and 23% lower (p<0.01) for the HFS2, HFS3, and HFS4, respectively. The predicted methane efficiencies ($CO_2eq$) per kg of LW at slaughter ($4.3{\pm}0.15$), carcass weight ($8.8{\pm}0.25kg$) and kg of edible protein ($44.1{\pm}1.29$) were also lower (p<0.05) in the HFS4. In particular, irrespective of the HSF, feed supply and ratio changes had a more positive impact on emission intensities when crossbred 1/2 Red Angus cattle were fed than in their crossbred counterparts. Conclusion: Modest improvements on feeding practices and integrated modelling frameworks may offer potential trade-offs to respond to climate change in Vietnam.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.90-104
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• 2001

This study is aimed to analyze and to evaluate the revegetation and soil conservation technology in desertification-affected sandy land, resulting from the project of "Studies on the desertification combating and sand industry development". Main native plants for combating desertification : The general characteristics of vegetation distribution in desertified regions are partially concentrated vegetation distribution types including the a) desert plants in low zone of desert or sanddune of depressed basin, b) salt-resistant plants around saline lakes, c) grouped vegetation with Poplar and Chinese Tamarix of freshwater-lakes, saline-lakes and river-banks, d) gobi vegetation of gravel desert and e) grassland and oasis-woods around the alluvial fan of rivers, etc. Generally, Tamarix ehinensis Lour., Haloxylon ammodendron Bunge., Calligonum spp., Populus euphratica Oliver., Elaeagnus angustifolia L., Ulmus pumila L., Salix spp., Hedysarum spp., Caragana spp., Xanthoceras sorbifolia Bunge., Nitraria tangutorum Bobr., Lespedeza bicolor, Alhagi sparsifolia Shap., Capparis spinosa L., Artemisia arenaria DC., etc. are widely distributed in desertified regions. It is necessary for conducting research in the native plants in desertified regions. Analysis of intensive revegetation technology system for combating desertification : In the wind erosion region, the experimental research projects of rational farming systems (regional planning, shelterbelts system, protection system of oasis, establishment of irrigation-channel networks and management technology of enormous farmlands, etc.), rational utilization technology of plant resources (fuelwood, medicinal plants, grazing and grassland management, etc.), utilization technology of water resources (management and planning of watershed, construction of channel and technology of water saving and irrigation, etc.), establishment of sheltetbelts, control of population increase and increased production technology of agricultural forest, fuelwood and feed, etc. are preponderantly being promoted. And in water erosion region, the experimental research projects of development of rational utilization technology of land and vegetation, engineering technology and protection technology of crops, etc. are being promoted in priority. And also, the experimental researches on the methods of utilization of water (irrigation, drainage, washing and rice cultivation, etc.), agricultural methods (reclamation of land, agronomy, fertilization, seeding, crop rotation, mixed-cultivation and soil dressing works, etc.) and biological methods (cultivation of salt-resistant crops and green manure and tree plantation, etc.) for improvement of saline soil and alkaline soil in desertified-lands are actively being promoted. And the international cooperations on the revegetation technology development projects of desertified-lands are sincerely being required.