Rice distillers’ byproduct and molasses-urea blocks containing biochar improved the growth performance of local Yellow cattle fed ensiled cassava roots, cassava foliage and rice straw

Kong Saroeun, T R Preston¹ and R A Leng²

Faculty of Agriculture, Svay Rieng University, Cambodia
kong.saroeun@sru.edu.kh
¹ Centro para la Investigación en Sistemas Sostenibles de Producción Agropecuaria (CIPAV), Carrera 25 No 6-62 Cali, Colombia
² University of New England, Armidale NSW, Australia

Abstract

Twenty male cattle of local Yellow breed with an average body weight of 92.6 kg were allocated in individual stalls to a 2*5 factorial arrangement of treatments with two replicates. The two factors were: biochar inclusion in urea-molasses blocks at levels of: 0, 2, 4, 6 and 8%; and rice distillers’ byproduct (RDB) at zero or 4% in diet DM. The basal diet was ensiled cassava root, dried cassava foliage, rice straw and molasses-urea blocks.

Growth rates of local Yellow cattle were increased when the molasses-urea blocks contained from 2 to 8% biochar (intakes of biochar ranged from 0.05 to 0.33% of diet DM); and when rice distillers’ byproduct was fed at 4% of diet DM. There were related improvements in feed conversion with both additives. There were no additional benefits from combining the two additives.

Key words: biomass, carbon sink, feed additives, feed conversion, gasification, ruminants

Introduction

Molasses-urea blocks (MUB) provide ruminants with essential sources of nutrients (urea, carbohydrate and minerals) usually deficient in many forages and most crop residues. MUB feeding has given positive results in many parts of the world (Kunju 1986; Hadjipanayiotou et al 1993; Liu J-X et al 1995). The block can be prepared using several formulations depending on the supply and price of the needed ingredients.

Biochar is a by-product of the high-temperature carbonization of fibrous biomass which has been shown to improve soil fertility and act as a sink for atmospheric carbon (Lehman 2007; Lehman and Joseph 2009) and increase yield of vegetables (Chhay Ty et al 2013a,b; Sisomphone et al 2012a,b,c), rice (Southavong and Preston 2011; Huy Sokchea et al 2013).and forage crops such as Taro (Colocasia esculenta) (Bouravong et al 2017). The first application of biochar in diets of cattle was reported by Leng et al (2011) with improved growth rates from adding 1% of biochar to a diet of cassava roots, urea and cassava foliage. According to Leng et al (2012) addition of biochar to an in vitro incubation of this diet reduced by 12% the production of methane. More recent studies in Lao PDR (Sengsouly and Preston 2017) showed that 1% biochar in the fattening diet (ensiled cassava root, urea and cassava foliage) of local cattle improved growth rates and feed conversion by 15%.

The yeast-fermentation of rice, and subsequent distillation of alcohol, to make “rice wine” is widely practised in rural areas of SE Asia. The residue (rice distillers’ by-product), known as “Bar Rao” in Cambodia, “Hem” in Vietnam and “Quilao” en Lao PDR, is usually fed to pigs as it is rich in protein (Luu Huu Manh et al 2000, 2009). However, recent research in Lao PDR has shown that it also may act as a “prebiotic” with beneficial effects when fed at 4% of the diet on N retention in growing pigs (Sivilai and Preston 2016) and on the overall feed conversion during the pregnancy-lactation cycle of gilts (feed consumed per unit weight of weaned piglets) (Silivai et al 2018). Improved growth rates have also been reported in cattle fed 4% rice distillers’ by-product as a supplement to ensiled cassava roots-urea and cassava foliage (Sengsouly and Preston 2017; Sangkhom et al 2017).

The hypotheses that were tested in this research were: (i) biochar incorporated in molasses-urea blocks would have positive effects on growth performance of local Yellow cattle; and (ii) that there would be synergistic benefits by also adding 4% of rice distillers’ byproduct to the diet.

Location and duration

The experiment was carried out at Svay Rieng University, Svay Rieng province, Cambodia, from May to August 2016.

Materials and methods

Twenty male cattle of local Yellow breed with an average body weight of 92.6 kg and 16 months of the age were housed in individual stalls (Photo 1). They were dewormed using Levamisol prior to the experiment.

Cassava root and leaves of the bitter variety were bought from farmers after root harvesting. The roots were chopped by machine and ensiled in containers; the leaves were sun-dried under sunlight, chopped by machine and stored in closed polyethylene bags. Rice distillers’ byproduct was bought from the rice wine producer in a nearby village. Biochar was made from rice husks carbonized in a gasifier stove (Photo 3).

Photo 1. Experimental Cattle housing	Photo 2. Cassava root chopping for ensiling.

Photo 3. The gasifier cook stove for carbonizing rice husks to make biochar

Treatments and experimental design

Local Yellow cattle (n=20) were used for this research. The experiment was designed as a 2*5 factorial in completely randomized design with 2 replications. The two factors were:

• Biochar inclusion in urea-molasses block at levels of: 0, 2, 4, 6 and 8%.
• Rice distillers’ byproduct: 0 or 4% in diet DM

The basal diets were rice straw, ensiled cassava root, and dried cassava foliage. Rice straw was fed ad libitum, cassava foliage was fed at 1% of live weight (DM basis), rice distillers’ byproduct was fed at 4% of DM intake and ensiled cassava root ad libitum.

Data collection

Feeds offered and refused were recorded daily and weighed to measure daily feed intake. Representative samples were collected for chemical analysis. The animals were weighed at the beginning of the study and then every 2 weeks until the end of the trial.

Chemical analysis

The feeds offered, and refusals were analyzed for DM using microwave radiation (Undersander et al 1993) and N and ash following the methods of AOAC (1990).

Statistical analysis

Live weight gain was measured as the linear regression of live weight (Y=kg) on time (X=days) during the experiment. All variables were analyzed by the General Linear Model (GLM) option in the ANOVA program of the Minitab 14 (2000) software. Sources of variation were: Biochar level, Rice distillers’ byproduct supplementation, interaction between Biochar level and Rice distillers’ byproduct supplementation and error.

Results

DM and crude protein in diet ingredients

The composition of the diet ingredients (Table 1) was comparable to those reported in the Feedipedia data base (www.feedipedia.org).

The biochar served two purposes (Table 2): as a binder for the blocks replacing cement and as a potential additive (prebiotic?). As a percentage of the diet DM, the levels of biochar ranged from zero to 0.14% in the absence of RDB and from zero to 0.31% when 4% RDB was added to the diet. These dietary levels of biochar are much lower than the 1% in diet DM fed previously to cattle (Leng et al 2014; Sengsouly and Preston 2016) and goats (Silivong et al 2016; Thuy Hang et al 2018). The crude protein level in the blocks (55%) was derived almost exclusively from the 15% of urea, which was higher than the 10% urea level used in blocks fed commercially to cattle and sheep grazing low quality pastures in Northern Australia (Leng R A , personal communication).

DM intake

The treatments had no effect on intakes of major diet ingredients (Table 3). However, intakes of the molasses blocks and consequently of biochar were higher when the diets were supplemented with RDB.

Live weight gain and feed conversion

The initial analysis (Figure 1) indicated that growth rate was increased by supplementation with rice distillers’ byproduct and tended to increase (p=0.14) with increasing concentration of biochar in the molasses-urea blocks However, the comparison of individual treatments showed that the difference was between zero biochar and all levels of biochar between 2 and 8%.

Figure 1. Effect of supplementation with molasses-urea blocks containing biochar and of rice distillers byproduct on the growth rate of cattle fed ensiled cassava root, urea, cassava foliage and rice 7) (Effect of biochar: p=0.14; effect of RDB p=0.017)

When the analysis was run for the comparison of zero biochar versus all levels of biochar in the blocks (from 2 to 8%) the overall increase in growth rate due to biochar was 43% and the confidence level increased to p=0.011; the comparable improvement in feed conversion was 35% (Table 4; Figure 2). Comparable improvements for the effects of RDB were 51 and 37% for growth and feed conversion respectively.

Figure 2. Effect of biochar and/or supplementation with rice distillers’ byproduct on growth rate of local Yellow cattle fed ensiled cassava roots, cassava foliage, rice straw and molasses-urea blocks (biochar was incorporated in he blocks at levels of 0, 2, 4, 6 and 8%) (results for biochar are the average of the levels 2-8%)	Figure 3. Effect of biochar and/or supplementation with rice distillers’ byproduct on feed conversion of local Yellow cattle fed ensiled cassava roots, cassava foliage, rice straw and molasses-urea blocks (biochar was incorporated in the blocks at levels of 0, 2, 4, 6 and 8%) (results for biochar are the average of the levels 2-8%)

Discussion

It appeared that the two additives, both RDB and biochar, were having similar effects. In the absence of RDB, biochar (average for 2-8% in the MUB) increased growth rate by 43%% while in the absence of biochar the RDB increased growth rate by 51%. Improvement in growth rate with the combined supplements was 60% but was not different from either supplement fed alone. These positive results are supported by earlier findings where: (i) biochar (1% of diet DM) increased growth rate of local Yellow cattle fed fresh cassava roots and cassava foliage from 103 to 129 g/day (Leng et al 2010); and (ii) 1% biochar in a diet of ensiled cassava root, urea and cassava foliage increased growth rate from 378 to 434 g/d (Sengsouly and Preston 2016). Similar benefits from feeding biochar have been reported in: (iii) goats fed Bauhinia acuminata foliage and cassava foliage (LWG from 39 to 49 g/day; Silivong et al 2016) and (iv) goats fed urea-treated cassava stems and cassava foliage (N retention increased from 3.03 to 4.42 g/d; Thuy Hang et al 2018).

It has been proposed that the mode of action of both rice distillers’ byproduct and biochar could be their capacity to bind toxins from the feed which are then either excreted in the feces and/ or provide habitat for microbial biofilms in/on the biochar surfaces in the animal’s gut microbiome that use the toxins in their energy metabolism (as discussed by Leng 2017).

Contamination of the feed with mycotoxins or the presence in the cassava foliage of hydrocyanic acid precursors could be the reasons for the overall low growth rates and the positive responses from supplementation with relatively inert materials with large surface areas to weight such as biochar and rice distillers’ byproduct.

The intakes of molasses-urea blocks were very low (maximum level reached was only 4% of DM intake) with the result that the recorded crude protein level was only 9-10% in diet DM. This could be one reason why growth rates were relatively low (170-320 g/day). The low intakes were not related to the level of biochar in the blocks and more likely were the consequence of setting the urea at too high a level (15%). The outcome was the much lower intake of biochar in the present trial (from 0.05 to 0.3% of the diet DM; Figure 4) compared with previously reported experiments when the offer level has been 1% of the diet DM.

Figure 4. Biochar intake as a function of level of biochar in the molasses-urea blocks, in presence or absence of supplementary rice distillers’ byproduct.

Biochar is a low-cost byproduct that can be made at farm level from a range of fiber-rich biomass sources (Dao et al 2013). The related viewpoint is that the biochar fed to animals will probably be 100% excreted in the feces where it will act as a sink for atmospheric carbon (Lehman 2005) and as a soil ameliorator which enhances plant growth (Lehman and Joseph 2014; Preston 2015) and conserves soil nitrogen (Bouravong et al 2017). Thus, there is little financial incentive to reduce the offer level.

These findings should be considered as preliminary indications of potential production benefits from supplementing cattle with biochar through the medium of molasses-urea blocks. The hypothesis that biochar is largely acting as a convenient place for the detoxification of toxic elements appears to be a new concept and, if proven, may indicate that microbes in the dense population of the gut microbiome of the ruminant may rapidly evolve the required genes by horizontal gene transfer facilitated by close contact with organisms that must be present in the soil or in the gut, perhaps as persistor cells from the contaminating soil on the feed materials.

Conclusions

• Growth rates of local Yellow cattle (fed ensiled cassava roots, cassava foliage, rice straw and molasses-urea blocks) were increased when biochar was added to the blocks (at levels of 2 to 8%); and when rice distillers’ byproduct was fed at 4% of diet DM. There were related improvements in feed conversion from each of the additives.
  
  
• There were no benefits from combining the two additives.

Acknowledgements

We thank the MEKARN II project, financed by Sida, for supporting this research, and students Som Sarak and Chea Piseth from Svay Rieng University, for their technical help.

References

AOAC 1990 Official Methods of Analysis. Association of Official Analytical Chemists. 15^th edition (K Helrick editor). Arlington pp 1230

Bouaravong B, Dung N N X and Preston T R 2017 Effect of biochar and biodigester effluent on yield of Taro (Colocasia esculenta) foliage. Livestock Research for Rural Development. Volume 29, Article #69. http://www.lrrd.org/lrrd29/4/boun29069.html

Chhay Ty, Vor S, Borin K and Preston T R 2013a Effect of different levels of biochar on the yield and nutritive value of Celery cabbage (Brassica chinensisvar), Chinese cabbage ( Brassica pekinensis), Mustard green (Brassica juncea) and Water spinach (Ipomoea aquatica). Livestock Research for Rural Development. Volume 25, Article #8. Retrieved September 29, 2014, from http://www.lrrd.org/lrrd25/1/chha25008.htm

Chhay Ty, Phalla M, Borin K and Preston T R 2013b Synergism between biochar and biodigester effluent as soil amenders for biomass production and nutritive value of Mustard green (Brassica juncea). Livestock Research for Rural Development. Volume 25, Article #57. Retrieved September 29, 2014, from http://www.lrrd.org/lrrd25/4/chha25057.htm

Dao T T, Canh N T, Trach N X and Preston T R 2013 Effect of different sources of biochar on growth of maize in sandy and feralite soils. Livestock Research for Rural Development. Volume 25, Article #59. http://www.lrrd.org/lrrd25/4/dao25059.htm

Hadjipanayiotou M, Verhaeghe L, Kronfoleh A R, Labban L M, Amin M, Al-Wadi M, Badran A, Dawa K, Shurbaji A, Houssein M, Malki G, Naigm T, Merawi A R and Harres A K 1993 Urea blocks. II. Performance of cattle and sheep offered urea blocks in Syria. Livestock Research for Rural Development, Volume 5, Number 3:16-23

Kunju P J G 1986 Urea molasses block lick - a feed supplement for ruminants. In: Rice Straw and Related Feeds in Ruminant Rations, SUP Publication No 2 pp 261-274 (Editors: M N M Ibrahim and J B Schiere). Kandy Offset Printers Ltd:Sri Lanka

Lehmann J 2007 A handful of carbon. Nature 447, 143-144 http://www.css.cornell.edu/faculty/lehmann/publ/Nature%20447,%20143-144,%202007%20Lehmann.pdf

Lehman J and Joseph S (Editors) 2009 Biochar for Environmental Management. Earthscan. United Kingdom and United State ISBN:978-1-84407-658-1

Leng R A, Preston T R and Inthapanya S 2012a Biochar reduces enteric methane and improves growth and feed conversion in local “Yellow” cattle fed cassava root chips and fresh cassava foliage. Livestock Research for Rural Development. Volume 24, Article #199. Retrieved April 3, 2015, from http://www.lrrd.org/lrrd24/11/leng24199.htm

Leng R A, Inthapanya S and Preston T R 2012b Biochar lowers net methane production from rumen fluid in vitro.Livestock Research for Rural Development. Volume 24, Article #103. Retrieved November 6, 2017, from http://www.lrrd.org/lrrd24/6/sang24103.htm

Leng R A 2017 Biofilm compartmentalisation of the rumen microbiome: modification of fermentation and degradation of dietary toxins. Animal Production Science. 57(11) 2188-2203. https://doi.org/10.1071/AN17382

Liu J-X, Wu Y-M, Dai X-M, Yao J, Zhou Y-Y and Chen Y-J 1995 The effects of urea-mineral lick blocks on the liveweight gain of local yellow cattle and goats in grazing conditions. Livestock Research for Rural Development. Volume 7, Article #17. Retrieved November 6, 2017, from http://www.lrrd.org/lrrd7/2/2.htm

Manh L H, Xuan Dung N N, Kinh L V, Binh T C, Thu Hang B P and Phuoc T V 2009 Composition and nutritive value of rice distillers’ by-product (hem) for small-holder pig production. Livestock Research for Rural Development. Volume 21, Article #224. Retrieved June 29, 2016, from http://www.lrrd.org/lrrd21/12/manh21224.htm

Minitab 2000 Minitab reference Manual release 13.31. User’s guide to statistics. Minitab Inc., USA

Preston T R 2015 The role of biochar in farming systems producing food and energy from biomass. In: Geotherapy: Innovative Methods of Soil Fertility Restoration, Carbon Sequestration and Reversing CO2 Increase (Editor: Thomas J Goreau) CRC Press, Tayler and Francis Group, Boca Raton, Florida USA

Sangkhom I, Preston T R, Leng R A, Ngoan L D and Phung L D 2017 Rice distillers’ byproduct improved growth performance and reduced enteric methane from “Yellow” cattle fed a fattening diet based on cassava root and foliage (Manihot esculenta Cranz). Livestock Research for Rural Development. Volume 29, Article #131. Retrieved November 6, 2017, from http://www.lrrd.org/lrrd29/7/sang29131.html

Sengsouly P and Preston T R 2016 Effect of rice-wine distillers’ byproduct and biochar on growth performance and methane emissions in local “Yellow” cattle fed ensiled cassava root, urea, cassava foliage and rice straw. Livestock Research for Rural Development. Volume 28, Article #178. http://www.lrrd.org/lrrd28/10/seng28178.html

Silivong P and Preston T R 2016 Supplements of water spinach (Ipomoea aquatica) and biochar improved feed intake, digestibility, N retention and growth performance of goats fed foliage of Bauhinia acuminata as the basal diet. Livestock Research for Rural Development. Volume 28, Article #98. http://www.lrrd.org/lrrd28/5/sili28098.html

Sivilai B, Preston T R, Hang D T and Linh N Q 2018a Effect of a 4% dietary concentration of rice distillers’ byproduct, or of brewers' grains, on growth rate and feed conversion during pregnancy and lactation of native Moo Lath gilts and their progeny. Livestock Research for Rural Development. Volume 30, Article #20. http://www.lrrd.org/lrrd30/1/lert30020.html

Sivilai B, Preston T R, Leng R A, Hang D T and Linh N Q 2018b Rice distillers’ byproduct and biochar as additives to a forage-based diet for growing Moo Lath pigs; effects on growth and feed conversion. Livestock Research for Rural Development. Volume 30, Article #111. http://www.lrrd.org/lrrd30/6/lert30111.html

Sokchea H, Borin K and Preston T R 2013 Effect of biochar from rice husks (combusted in a downdraft gasifier or a paddy rice dryer) on production of rice fertilized with biodigester effluent or urea. Livestock Research for Rural Development. Volume 25, Article #4. Retrieved November 6, 2017, from http://www.lrrd.org/lrrd25/1/sokc25004.htm

Southavong S and Preston T R 2011 Growth of rice in acid soils amended with biochar from gasifier or TLUD stove, derived from rice husks, with or without biodigester effluent. Livestock Research for Rural Development. Volume 23, Article #32. Retrieved November 6, 2017, from http://www.lrrd.org/lrrd23/2/siso23032.htm

Southavong S, Preston T R and Man N V 2012a Effect of soil amender (biochar or charcoal) and biodigester effluent on growth of water spinach (Ipomoea aquatica). Livestock Research for Rural Development. Volume 24, Article #26. http://www.lrrd.org/lrrd24/2/siso24026.htm

Southavong S, Preston T R and Man N V 2012b Effect of biochar and biodigester effluent on growth of water spinach (Ipomoea aquatic) and soil fertility. Livestock Research for Rural Development. Volume 24, Article #34. http://www.lrrd.org/lrrd24/2/siso24034.htm

Southavong S, Preston T R and Man N V 2012c Effect of biochar and charcoal with staggered application of biodigester effluent on growth of water spinach (Ipomoea aquatica). Livestock Research for Rural Development. Volume 24, Article #39. http://www.lrrd.org/lrrd24/2/siso24039.htm

Thuy Hang L T, Preston T R, Leng R A and Ba N X 2018 Effect of biochar and water spinach on feed intake, digestibility and N-retention in goats fed urea-treated cassava stems. Livestock Research for Rural Development. Volume 30, Article #93. http://www.lrrd.org/lrrd30/5/thuyh30093.html

Received 20 June 2018; Accepted 30 July 2018; Published 3 September 2018

Go to top