TOSOLY

COL, United States
COL, United States

Time filter

Source Type

Leng R.A.,University of New England of Australia | Preston T.R.,TOSOLY
Livestock Research for Rural Development | Year: 2010

Rumen fermentation results in the production of a pool of reduced cofactors in the pathways of catabolism of organic matter within rumen microbes. These reduced cofactors are regenerated by 1) synthesis of microbial cells, 2) production of more reduced end products such as propionate and 3) saturation of unsaturated long chain fatty acids but by far the largest proportion of reduced cofactor appear to be regenerated by 4) formation of hydrogen. The concentration of hydrogen in rumen fluid negatively feeds back on the rate of fermentation and microbial growth. The rumen ecosystem has evolved to remove this hydrogen through growth of Archae that obtain energy for their growth by reducing carbon dioxide to methane and water in the rumen. Ruminal methanogenesis represents a loss of dietary energy to the animal and it is a significant greenhouse gas. Ruminants are credited with a large proportion of the methane accumulating in the world's atmosphere and a high proportion of the radiative heat forcing of greenhouse gases that have accumulated in the atmosphere. These factors have led to a global search for strategies (including nutritional intervention) to mitigate methane emission from ruminants. The use of nitrate as a hydrogen sink has been down played, due to the possible toxic effects of nitrite that under some circumstances is formed as an intermediate during the reduction of nitrate to ammonia in the rumen. A few reports have examined the potential of nitrate in vitro as a methane reducing feed additive, which appears to lower methanogenesis consistently. The rumen ecosystem and the animal need time to adapt to any fermentable N source including urea and nitrate. The requirements for minerals in different dietary conditions appear to be important in determining the microbial consortiums that use these fermentable N sources.The potential of nitrate conversion ammonia to act as a hydrogen sink in the rumen was reviewed (Leng 2008) with a clear indication emerging that it is entirely feasible that nitrate could be used as a fermentable N source by ruminants provided the rumen ecosystem was allowed to adapt over a sufficiently long period and provided certain nutritional conditions were met. In particular the availability of sulphur appears to be a crucial issue. Information derived from other microbial, anaerobic ecosystems showed that in the presence of fermentable organic matter and a source of sulphur and nitrate, nitrate reducing organisms developed that can both reduce nitrate to ammonia and oxidize sulphide to sulphate (NRSOB) without release of nitrite. At least one prominent rumen organism has this capacity (Wollinella succinogenese) and may be termed an NRSOB. Studies from the MEKARN group have demonstrated that ruminants fed low protein agro industrial byproducts can utilize nitrate as a fermentable nitrogen source. These groups have been the first to show that nitrate can be fed to ruminants safely under practical conditions and maintain or increase production. Two other groups, with the facilities to measure methane production, have concentrated on the extent to which replacing urea with nitrate salts lowers methane production. Depending on diet and inclusion rate of nitrate, the reduction in methane production has varied from 16-50%. Approximately 1 mole of nitrate in a diet reduces methane production by 10% and there is evidence of an interaction with dietary sulphur levels The major limitations to progress in using these alternative fermentable N sources that also act as high affinity electron acceptor has been the production of methaemoglobinaemia that results from nitrite generated in the rumen. The specialized nature and expensive equipment for measuring respired gases from ruminants has also become a major limitation to progress. Considerable advancement appears possible by a new approach where the ratio of methane to carbon dioxide in air receiving the ruminants breath are used to calculate the percentage lowering of methane release from the animal. This approach is possible as it is well demonstrated that where the only intervention is to replace urea with nitrate in a diet the animal's energy metabolism(carbon dioxide production) is a constant in both control(urea fed) and treatment(nitrate fed). In the present studies a modification of published methods have been used to assess the potential reductions in methane that can be achieved when providing alternative electron acceptor via nitrate in the diet and manipulation of other minerals to promote in particular nitrate reducing sulphide oxidation systems The simplistic and inexpensive requirements make this a useful approach with potential to increase the rate of progress at low cost.


Phuong L.T.L.,Hue University | Ngoan L.D.,Hue University | Preston T.R.,TOSOLY
Livestock Research for Rural Development | Year: 2013

The aim of this study was to determine the effect of paddy rice supplementation on growth performance of rabbits fed a basal diet of foliage of Malvaviscus penduliflorus. Thirty five rabbits (New Zealand × Local) were arranged in a completely randomized design with 5 treatments, corresponding to paddy rice levels of 0, 1, 2, 3 and 4% of live weight. Malvaviscus penduliflorus was fed ad libitum. There was no effect of paddy rice level on feed intake, but weight gain and feed conversion were improved almost threefold when paddy rice supplied half the diet compared with Malvaviscus foliage fed alone. Mortality was 60% when Malvaviscus foliage was the sole diet.


du Hang T.,Hue University | Preston T.R.,TOSOLY
Livestock Research for Rural Development | Year: 2010

Oxalate levels in 3 species of taro were higher in petioles (range of 1326 to 3567 mg/100 g DM) than in leaves (770 to 2531 mg/100g DM), and within each plant part, values were highest for Alocacia odera and lowest for Xanthosoma nigra, with intermediate values for Colocacia esculenta. Sun-drying, soaking, cooking and ensiling all reduced the concentration of oxalate but the effects were most pronounced (50% reduction) for cooking and ensiling. DM and crude protein intakes of pigs fed a basal diet of maize, rice bran, cassava root meal and fish meal did not differ when ensiled taro leaves (ETL) replaced fish meal at up to 30% silage in the diet DM; however, intake of fiber increased linearly with replacement rate of ETL. Growth rate was reduced only slightly up to the 30% inclusion rate of ETL, at which point the growth rate was markedly reduced. The trends for feed conversion were similar to those for weight gain. The results suggest that ETL can replace up to 30% of the dietary fish meal (20% ETL in the diet DM) in diets for growing pigs without loss of performance.


Tu D.T.M.,Mekong University | Dong N.T.K.,Can Tho University | Preston T.R.,TOSOLY
Livestock Research for Rural Development | Year: 2012

Two experiments were conducted on a private farm in Binh Thuy District, Cantho City to study: (i) the yield and composition of duckweed cultivated with different levels of biodigester effluent; and (ii) the effect on duckweed composition of a "shock" treatment of transferring high quality duckweed to plain water containing no nutrients. In experiment 1, the treatments were 6 levels (0, 4, 8, 12, 16 and 20%) of biodigester effluent added to fresh water in plastic containers containing duckweed. The surface of water in each container was 0.4 m 2with 20 cm depth giving a volume of 60 liters. Duckweed was inoculated at a rate of 400 g/m 2. The yield of duckweed was measured over a period of 14 days by removing and weighing one third of the biomass every 48 h. There was a curvilinear response in yield, and in crude protein content of the duckweed, to level of effluent with maximum values for both at a ratio of 12% effluent and 88% water (72 mg N/liter). Duckweed from this treatment was then transferred to fresh water and the composition studied over 5 days. The content of starch increased and that of crude protein decreased with increasing time in the fresh water. It was concluded that yield and crude protein content of duckweed was optimized when the culture medium contained 12% biodigester effluent and 88% water. The "shock" treatment of transferring the best quality duckweed to nutrient-free fresh water led to decreases in crude protein and corresponding increases in starch. However, the effects were relatively small and unlikely to have significance from the points of view of duckweed as a feed for ducks or as a substrate for ethanol production.


An experiment was carried out in the research farm of An Giang University from January to April 2011.to compare integrated culture of Tilapia (Oreochomis niloticus) and Common carp (Ciprinus carpio) in an intensive indoor system with earthworms as feed, with an outdoor natural pond system, using biodigester effluent as fertilizer and duckweed as feed supplement. There were four treatments with three replicates in a completely randomized design with mixed stocking of Common carp and Tilapia (50: 50) at low and high densities (3 or 5 fish//m2 in the natural ponds and 60 or 100 fish/m3 in the intensive indoor system. In the outdoor system the fish were raised in natural ponds (4m2), seeded with duckweed and fertilized with biodigester effluent. In the indoor system, the fish were raised in PVC tanks (0.5m3) in an enclosed building and fed with earthworms. Growth rates at the higher stocking rate were lower for the Common carp in the pond system and tended to be lower for the Tilapia as compared with the low stocking rate. In the indoor system where the fish were fed ad libitum, the growth rates were less affected by stocking density. In the outdoor pond system growth rates were much higher for the Tilapia than for the Çommon carp. In contrast, in the intensive indoor system, there were no differences between the two species. The Tilapia gained from 0.95 to 1.32 g/day at high and low densities in the natural pond system but only 0.26 and 0.33 g/day in the intensive system. In the natural pond system the net fish yields were equivalent to 9 and 10 tonnes/ha/year for the low and high densities, respectively. Environmental pollution, as measured by concentrations of total ammonia-N and nitrite in the water, was some 50% greater in the intensive system. An economic analysis, on the basis of gross returns from the fish less the variable costs (fingerlings and feed), showed positive margins for all species/density combinations in the natural pond system compared with the negative margins for the intensive indoor system.


The first experiment was conducted to evaluate effects on fermentation characteristics and nutritive value of ensiling Tithonia diversifolia leaves and petioles with leaves and petioles of Taro (Colocacia esculenta), with or without 5% molasses. The second experiment was a 4*4 Latin square arrangement applied to 4 crossbred castrated male pigs (60 kg live weight) fed diets with four levels of ensiled Tithonia:Taro with 5% molasses equivalent to 0, 10, 15 and 20% substitution of a basal diet ir rice bran, broken rice, soybean meal and fish meal. The pigs were housed in metabolism cages for consecutive periods of 15 days, with collection of feces during the last 5 days of each period. All silages had an attractive smell. The pH in the ensiling mixture increased as the level of Tithonia was raised, and decreased with ensiling time, the decrease being more pronounced when molasses was added. Lactic acid decreased with increased level of Tithonia and increased with ensiling time, the relative increase being less marked as Tithonia levels were raised. In all cases the lactic acid concentration was higher with addition of molasses. There were only slight decreases in digestibility coefficients of DM, CP and NDF (range of 4-5%) as the Tithonia: Taro silage was increased from 0 to 20% of the diet. It is concluded that Tithonia:Taro silage is of relatively high nutritive value, in terms of digestibility of the DM, NDF and crude protein for pigs.


Phuong T.B.,Nong Lam University | Khang D.N.,Nong Lam University | Preston T.R.,TOSOLY
Livestock Research for Rural Development | Year: 2012

The objective of this study was to determine the effect of potassium nitrate versus urea, and of supplementary sulphur, on growth performance of cattle fed molasses and cassava foliage. Sixteen growing Laisind female cattle (Red Sindhi*local "Yellow" breed) with á range of initial live weight of 187-234kg were divided into two blocks according to live weight and within blocks were allocated at random to 8 treatments arranged as a 2*2*2 factorial with 2 replications. The factors were source of NPN (potassium nitrate: 6% of diet DM basis or urea: 1.8% of diet DM basis), level of added sulphur (0 or 0.8% S) and source of cassava foliage (fresh foliage or dried leaf meal). DM intake was not affected by NPN source, but was depressed by adding 0.8% sulphur and was lower for the treatment with fresh cassava foliage compared with leaf meal. After correcting the data by covariance for differences in initial live weight, growth rate was depressed by adding 0.8% sulphur to the diet but was not affected by source of NPN or source of cassava foliage. The ratio of methane to carbon dioxide was reduced by feeding potassium nitrate rather than urea and by fresh cassava foliage compared with cassava leaf meal.


An experiment was conducted at the Goat and Rabbit Research Centre to determine effects on feed intake, average daily gain (ADG), feed conversion ratio (FCR) and economic returns of New Zealand White rabbits raised on two feeding systems: sweet potato (Ipomoea batatas) vines with supplementation of paddy rice and Guinea grass plus commercial concentrate. There were 5 levels of supplement (paddy rice or concentrate): 0, 10, 20, 30 and 40 g/head/day. A total of 30 male growing rabbits at 6 weeks of age were equally divided into 2 main groups of 15 each to be fed on either of the two basal diets. Each of the two main groups was further divided into 5 sub-groups (treatments) of 3 rabbits each. The rabbits were housed and fed in individual cages. The experiment lasted 10 weeks following 7 days of adaptation. The system of sweet potato vines and paddy rice supported higher growth rates and better feed conversion than Guinea grass plus concentrate. In the Guinea grass-concentrates system the feed conversion became worse as the level of supplement increased; in contrast on the sweet potato vine-paddy rice system, feed conversion was the same irrespective of the level of supplementation.


Rodriguez L.,TOSOLY | Preston T.R.,TOSOLY
Livestock Research for Rural Development | Year: 2010

The feedstocks used in a down-draft gasifier were sugar cane bagasse and mixed stems of Mulberry (Morus alba) and Tithonia (Tithonia diversifolia). The tests were done under commercial conditions over an extended period (90 days) on a farm in Colombia. The bagasse was the byproduct of the extraction of the juice from sugar cane stalks, which was fed to pigs; the stems were the residues after the leaves and (in the case of the Mulberry) the rind had been consumed by confined goats The 10KW gasifier (Ankur WBG10) was imported from India. Rates of consumption of the feedstock were similar for the bagasse and the stems (4.32 and 4.65 kg DM/h). The stems produced a greater percentage of biochar (11.7% of the DM in the feedstock) than the bagasse (8.5%). Management of the gasifier was simpler in the case of the stems as these flowed more easily in the hopper, whereas the bagasse tended to "bridge" requiring frequent agitation to maintain the gas flow. It was estimated that the bagasse from the 1.5ha of sugar cane required to feed a constant population of 45 pigs (about 50 kg DM daily), and the 1ha in forage trees for 20 breeding goats, could provide electrical energy yields of 50 KWh daily. The biochar residue (35% ash; 65% carbon) from the gasification of the bagasse and tree stems (2.5 ha) would be sufficient to condition 0.1 ha of crop land annually with the potential to sequester annually up to 5.4 tonnes of carbon dioxide.


Thu Hong N.T.,Angiang University | Preston T.R.,TOSOLY
Livestock Research for Rural Development | Year: 2013

Experiments were carried out at the farm of Angiang University from January to August 2011 to measure: (i) the effect of fertilization with biodigester effluent on biomass production of Tithonia diversifolia (Wild Sunflower); and (ii) the effect on intake and digestibility by growing goats of supplementing Tithonia diversifolia foliage with foliage from Sesbania sesban and/or Mimosa pigra. Biomass productivity of Tithonia was raised by 175% by increasing the level of fertilization with biodigester effluent from 20 to 60 kg N/ha. Feed DM intake was increased by from 11 to 23% and N retention by 30-32% when goats fed a basal diet of Tithonia were supplemented with foliage from either Mimosa pigra or Sesbania sesban, or the combination of both legume foliages.

Loading TOSOLY collaborators
Loading TOSOLY collaborators