| Livestock Research for Rural Development 26 (06) 2015 | Guide for preparation of papers | LRRD Newsletter |
1. Yeeleng (NUOL, Lao)
Hypothesis: The protein in Tithonia diversifolia is very soluble. Growth response of goats will be improved by supplementation with a source of “bypass protein” as in cassava foliage or with rumen fermentable carbohydrate from cassava root pulp
Project: Basal diet of Tithonia diversifolia with fresh cassava foliage, cassava pulp or combined cassava foliage and cassava bran; 4 growing goats about 10 kg LW in 4*4 Latin square with periods of 10 days. Measure intake, digestibility, N retention and methane emissions in eructed breath. Bamboo/wood metabolism cages.
2. Phontheb (SKU, Lao)
Hypothesis: Foliages from Leucaena and gliricidia contain tannins which form complexes with the protein and may reduce availability of peptides and amino acids needed by rumen micro-organisms. Supplementation with a source of soluble (easily fermentable) protein may improve performance of goats fed these foliages.
Project: Basal diets of Leucaena or Gliricidia with or without water spinach with 4 growing goats about 10 kg LW in 4*4 Latin square with periods of 10 days. Measure intake, digestibility, N retention and methane emissions in eructed breath. Bamboo/wood metabolism cages.
3: Souksakone (CU, Lao)
Hypothesis: Performance of goats fed a basal diet of cassava pulp and urea will be improved when they are supplemented with cassava foliage, or leucaena, rather than water spinach or elephant grass
Project: Basal diet of ensiled cassava pulp and urea; supplements are elephant grass (control), fresh cassava foliage (1% of live weight as DM) or Leucaena foliage (1% of LW as DM) or fresh water spinach (1% of LW as DM). Growing goats about 10 kg LW in 4*4 Latin square with periods of 10 days. Measure intake, digestibility, N retention and methane emissions in eructed breath. Bamboo/wood metabolism cages.
4. Duy, (NLU, Vietnam)
Hypothesis: An oil drench, which is known to reduce rumen protozoa and improve growth rate in ruminants, will also reduce methane production in eructed breath of growing cattle.
Project: From a group of young cattle, four will be selected and given a single drench of 500ml of soybean oil; four similar animals will be identified as the “control” treatment. Methane and carbon dioxide in eructed breath of the animals will be measured at weekly intervals over 4 successive weeks. On days following the gas measurements, rumen samples will be taken by stomach tube to measure populations of rumen protozoa.
5. Toum (NAFRI, Lao)
Hypothesis: A basal diet of ensiled cassava pulp and urea will support greater growth rates in Holstein cattle when supplemented with cassava foliage rather than when the forage source is elephant grass.
Project: Four groups each of 4 Holstein cattle (initial weight about 120 kg) will be allocated to diets of ad libitum ensiled cassava pulp and urea (3% of pulp DM) with foliage either from cassava or elephant grass at 1% of live weight (DM basis). Measurements are made of feed intake, growth rate and emissions of methane in eructed gas at 2 week intervals. Design is random block with two replicates of two treatments.
6. Souksamlane (NAFRI, Lao)
Hypothesis: Digestibility of legume foliages by ruminants will be increased by providing a supplement that supplies easily fermentable protein.
Project: Treatments in an in vitro rumen fermentation are leaf meals of Leucaena and Erythrina each supplemented with water spinach leaf meal or not supplemented. Design is 2*2 factorial with 4 replications. Measurements of gas and methane production at intervals of 6, 12, 24 hours and residual substrate DM at 24hours
7. Ms Tieu (N LU, Vietnam)
Hypothesis: The same as in (4)
Project: The same treatments as in (3) will be applied in an in vitro rumen fermentation. The substrate will be a mixture of cassava root pulp, cassava leaf meal and urea. Treatments will be levels of soybean oil of 0, 3, 6, 9 and 12% of weight of substrate DM. Four replicates of each treatment and measurements of total gas and methane content at 6, 12, 24 and 48 hours. After 48 hours measure the protozoa in the substrate.
Hypothesis: Digestibility of rice straw will be increased more by supplementation with fermentable protein than with non-protein nitrogen (urea)
Project: In vitro rumen fermentation with ground rice straw plus minerals as basal substrate. Treatments to give 1.5% N in straw DM are: urea, water spinach leaf meal, 50:50 mixture (as N) of urea and water spinach leaf meal, no supplement. Design is random block with 4 treatments and 4 replications.
9. Vor Sina (Cambodia)
Hypothesis: Methane production will be reduced when cassava root pulp and cassava roots are supplemented with cassava leaf meal or leaf meal from Erythrina poeppigian (a legume tree thought to contain bypass protein, and well consumed by goats). Urea is added to all substrates to ensure adequate levels of ammonia)
Project: In vitro rumen fermentation with ensiled cassava root or ensiled cassava root pulp supplemented with urea alone or together with cassava leaf meal or leaf meal from Erythrina poeppigiana. Design is 3*2 factorial with 4 replications with gas and methane measurement over 6, 12, 18 and 24h..
Hypothesis: Water spinach and ensiled Taro foliage (leaves + petioles) can provide all the supplementary protein needed by Mong Cai pigs fed chopped sugar cane stalks as the source of energy
Project: Three Mong Cai pigs are offered chopped sugar cane stalks (cut into lengths of 20cm) at 15% of live weight (fresh basis) and either fresh water spinach, ensiled Taro leaves + petioles, protein-enriched cassava pulp or soybean meal to provide 4 g crude protein per 1 kg live weight of the pigs. A mineral mixture is given on all treatments. Design is 4*4 Latin square with periods of 10 days on each diet. Measurements of intake, digestibility and N retention; and sugars in fresh and chewed residues of the sugar cane.
11. Putnapha (CU, Lao)
Hypothesis: Fermentation of cassava root pulp with yeast, after cooking and supplementation with urea and ammonium phosphate, will increase the content of true protein.
Manivanh N and Preston T R 2015: Protein-enriched cassava root meal improves the growth performance of Moo Lat pigs fed ensiled taro (Colocacia esculenta) foliage and banana stem. Livestock Research for Rural Development. Volume 27, Article #44. http://www.lrrd.org/lrrd27/3/noup27044.html
Project: Fresh cassava pulp (residue from starch extraction) (CP) and broken rice (BR) will be compared as feedstock for solid-state fermentation with yeast. The design is a random block with two treatments (CP and BBR) and with 4 replications. The substrates will be steamed, supplemented with urea and ammonium phosphate, and seeded with yeast. The procedure is similar to that employed in making rice wine with the modification of adding nutrients (N and P) to facilitate growth of yeast instead of production of alcohol. Measurements are made of crude and true protein in the feedstock and the loss of DM from the feedstock during the fermentation.
The protein enriched cassava pulp (PECP) will be compared with soybean meal as supplement to a basal diet of ensiled cassava pulp. The design will be a Latin square 4*4. Treatments are replacement of soybean meal by PECP at levels of 0, 33, 66 and 100%, fed to Mong CAi pigs. Measurements are made of N retention and digestibility of DM and crude protein
12. Sengsouly (SU, Lao)
Hypothesis: The residues of sugar cane stalk (after being used as energy source for pigs) can be used in a gasifier stove to produce a combustible gas (for cooking) and biochar as soil amendment. Project: The sugar cane stalks after being chewed by pigs will be compared with rice husks as feedstock in the gasifier stove. Measurements are made of gas composition, temperature in the gasifier, heat value of the gas and production of biochar. The biochar from the two feedstocks will be compared in a biotest with maize as the test plant.
13. Outhomphone (SKU, Lao)
Hypothesis: There will be carry-over effects from biochar when used as soil amendment in plots growing water spinach vegetable.
Project: 1*1m plots of water spinach are established to compare levels of addition of biochar of 0, 1, 2, 3, 4 (kg/m2). Water spinach is established from seed and harvested over three successive periods of 28 days. Design is random block with 4 replications. Measurements are made of DM and CP yield of the water spinach, and pH and water holding capacity of the soil after the last harvest.
14. Bounmay (SKU, Lao)
Hypothesis: Biochar, and/or peeling of the lower 3 cm, will increase the rate of germination and growth of stem cuttings of Erythrina
Project: Cuttings of Erythrina are planted in soil in one liter plastic bags and : (i) biochar is added at rates of 0, 1, 2, 3 and 4% of weight of soil; and (ii) the bottom 3 cm of the stem are peeled or not peeled. There are 4 replications of each of the treatments in a factorial 2*4 design. Measurements are made of rate of germination (days when first buds appear), and growth in height of the plants at intervals of 7 days. After seedlings are transplanted, soil is analysed for water holding capacity and pH
15. Chittakone (SKU, Lao)
Hypothesis: Establishing sugar cane is done by planting whole stems, the growing point or segments of the stem that have nodes. The latter method is usually done in a nursery after which individual plants are transplanted in the field. Application of biochar during the nursery stage is expected to accelerate the rate of germination and produce stronger seedlings.
Project:
Mature sugar cane stems are separated into segments each containing a node (The growing point). The segments are planted in plastic bags containing 1 kg of soil. The treatments are concentrations of biochar in the bags equivalent to: 0, 1, 2, 3 and 4% of the weight of soil. Biodigester effluent is mixed with the soil prior to planting in quantities equivalent to 20 kg N/ha (approximately 20 ml of effluet/bag). A production function design is used with 5 treatments (levels of biochar) and 3 replications. Measurements are made of days for first leaves to appear and plant height at intervals of 14 days over the total period of 56 days.
Rabbits
16. Kong Streyleap
Hypothesis:
Growth rate and feed conversion of rabbits fed water spinach will be
improved when they also have access to fresh sugar cane stalk and when their
diet is supplemented with biochar
Project: Growth trial of 8 weeks with 12 rabbits fed basal diet of water spinach, as sole feed (WS) or with free access to sugar cane stalk (WS-SCS). Design is 2*2 factorial with 3 replications of the four treatments. A small quantity of broken rice (5 g/day) is also fed as “carrier” for the biochar which is fed at 0.5g/day. Measurements are of daily feed intake and live weights every 7 days; DM content of the feces is measured at weekly intervals.
Feces are collected and bulked over the first 28 days of the trial. They are then used as fertilizer for maize in a “biotest” with 2 treatments: RF-Bio: Feces from rabbits fed biochar ; FR: feces from rabbits not fed biochar. There are 6 replicates of each treatment. Feces are added to soil in plastic bags of 1 litre capacity at levels equivalent to 5g N/m2.
17. Triet (NLU, Vietnam)
Hypothesis: The “plug-flow” configuration of a biodigester will produce more gas per unit substrate than the “dome” configuration.
Project: The two designs of biodigester will be constructed from 5 liter recycled water bottles arranged in a vertical or horizontal configuration. There will be 4 replications of each configuration. Cattle manure is used as substrate at 5% (as DM) of the influent with a retention time of 20 days. Measurements are made of pH, gas production and methane content of the gas, and residual, unfermented DM after 40 days of operation.
18. Yen Sopheap (Cambodia)
Hypothesis: When biodigesters are charged with fruit waste (rind from pomelo) gas production and methane content in the gas are increased when sodium bicarbonate is added in the start up phase. This experiment will study different times from startup that the sodium bicarbonate has to be added to ensure stable fermentation and normal gas production.
Project: Experimental biodigesters made from 5 litre recycled water bottles are used in a production function design with 5 treatments (10, 15, 20, 25 or 30 days that the sodium bicarbonate has to be added) and 3 replicates.
19. Philavong Somphanh
Hypothesis: Application of biochar to duckweed as feed for tilapia will improve pond water quality and growth rate of the fish.
Project: Tilapia fingerlings are fed duckweed in ponds supplemented with biochar at levels of 0, 0.5, 1,0 and 1.5 kg per m3 of pond volume. There are 2 replicates (ponds) of each treatment. Duckweed is grown and harvested in separate ponds fertilized with biodigester. The duckweed is fed at the daily rate of 5% (as DM) of fish live weight. The biochar is sprinkled over the duckweed when this is added to the ponds. Water quality criteria are measured weekly and fish growth at monthly intervals over 3 months. The ponds are 1m2 (1*1m) and 0.5m deep excavated in the ground and lined with plastic. Duckweed is grown in similar ponds, fertilized with biodigester effluent
20. Pok Theary
Hypothesis: Growth rates of duckweed fertilized with biodigester effluent will be increased when biochar is added to the water
Project: Plastic baskets (0.5*0.5m) lined with plastic film are used to grow duckweed. The treatments are levels of biochar of 0, 25, 50, 75 and 100 g/basket applied at the beginning together with 2.5 g N of biodigester effluent (about 5 liters). One third of the surface area of the duckweed is harvested daily and used for experiment 19. Yields of duckweed are recorded, the length of the roots and the concentration of DM and N.