Effect of Roughage Sources and Fibrolytic Enzyme Supplementation on Nutrient Digestion and Rumen Fermentation in Buffaloes Chalermpon YUANGKLANG a, Kraisit VASUPEN a, S. BUREENOK a, S.WONGSUTHAVAS a, A.C. BEYNEN a,e, Chalong WACHIRAPAKORN b, Pramote Paengkoum c, S. Paengkoum d, M. Phonvisay a and T. Vorlaphim a a Department of Animal Science, Faculty of Natural Resources, Rajamangala University of Technology Isan, Sakon Nakhon Campus, Phangkhon, Sakon Nakhon, 47160 Thailand b Department of Animal Science, Faculty of Agriculture, Khon Kaen University, Khon Kaen 4002 Thailand c School of Animal Production Technology, Institute of Agricultural Technology, Suranaree University of Technology, Muang, Nachon Ratchasima 30000 Thailand d Program in Agriculture, Faculty of Science and Technology, Nachonratchasima Rajabhat University, Muang, Nachon Ratchasima 30000 Thailand e Department of Animal Production, College of Food and Agricultural Sciences, King Saud University, Riyadh 11451, Kingdom of Saudi Arabia *Corresponding email: chayua@hotmail.com ABSTRACT The objective of present experiment was aimed to investigate the effect of roughage sources and fibrolytic enzyme supplementation on feed intake, nutrient digestion and rumen fermentation. Four rumen fistulated buffalo bulls about 3.7 years old with average initial BW of 430 + 25 kg were used in a 2x2 Latin square design. Buffaloes were received rice straw (RS) or urea-treated rice straw (UTS) with or without fibrolytic supplementation. Fibrolytic enzyme supplementation was added on top of concentrate diet. Concentrate diet was offered at 1.5%BW. Roughage was fully supplied. Roughage and total intakes expressed as kgdm/d, %BW and g/kgbw 0.75 were significantly difference (P<0.05) among treatments. Rumen parameters were altered by the roughage sources. Buffalo fed UTS was better in rumen fermentation end products than in buffalo fed RS. Enzyme supplementation was increased (P<0.05) both total and roughage intakes. Concentrate intake was similar among treatments. Based on the experiment data, it can be concluded that supplemental fibrolytic enzyme in buffalo diet improves feed intake, nutrient digestion and rumen fermentation end products particularly when roughage source is a low quality roughage. Keywords: Rice straw, Urea-treated Rice Straw, Fibrolytic Enzyme, Nutrient Digestion, Rumen Fermentation INTRODUCTION It is well known that rice straw is a main roughage source for ruminant animals including buffalo especially in the developing countries. Thailand is a country where rice production is the main crop production and the by-products from rice production is rice straw which is available for ruminant animals. However, it is well recognized that rice straw contains low crude protein content, high lignin content and low digestibility (Hart and Wanapt, 1992). There are many researchers attempt to improve the quality of rice straw by many methods such as urea treatment (Wanapat, 1999), NaOH (Khejornsart and Wanapat, 2010), alkali treatment (Wanapat et al., 1985) and ensiling (Yuangklang et al., 1994). Urea treatment is a conceivable method to increase the nutritive value and digestibility of rice straw (Wanapat and Pimpa, 1999). Fibrolytic enzyme is an exogenous enzyme which has been intensively investigated to improve fiber digestibility of forages. Beuchemin et al. (1995; 2003) reported that fibrolytic enzyme supplementation improve fiber digestibility of forage diet. Similar resulted with Krause et al. (1998) found that enzyme supplementation increased ADF digestibility when added to a high concentrate diet. Colombatto et Accepted April 10, 2013; Online February 24, 2014. 993
al. (2003) demonstrated that enzyme supplementation increased neutral detergent fiber digestibility. Shekhar et al. (2010) who found that fibrolytic enzyme supplementation increases milk production in dairy buffalo. In accordance with Hristov et al. (2000) found that fibrolytic enzyme supplementation increases ruminal and intestinal nutrient digestibility. Tang et al. (2008) studied the effect of yeast culture and fibrolytic enzyme supplementation improves in vitro gas production of cereal straw. Khanh et al. (2012) found that fibrolytic enzyme supplementation in fermented total mixed ration (FTMR) did not improve fiber digestion in dairy cows, but fibrolytic enzyme supplementation in total mixed ration (TMR) did increase fiber digestion. The objective of present experiment was aimed to investigate the effect of roughage sources and fibrolytic enzyme supplementation on feed intake, nutrient digestion and rumen fermentation in buffalo. MATERIALS AND METHODS Four rumen fistulated buffalo bulls about 3.7 years old with average initial BW of 430 + 25 kg were used in a 2x2 Latin square design. Buffaloes were received rice straw (RS) or urea-treated rice straw (UTS) with or without fibrolytic enzyme supplementation. Fibrolytic enzyme supplementation was added on top of concentrate diet. Concentrate diet was offered at 1.5BW. Concentrate diet was consisted of 57.0%cassava chip, 7.8%soybean meal, 11.4%whole cottonseed, 13.0%rice bran, 8.0%molasses, 2.0%tallow, 1.4%urea, 0.5%dicalcium phosphate, 0.5%premix and 0.2%sulfur.The ingredients of concentrate diet were demonstrated in Table 1. Roughage was fully supplied. Animals were housed in individual pens and they were moved to the metabolic crates for total collection. During the last 7 day of each period, total feces samples were quantitatively collected and weighed. Feces samples were analyzed for dry matter, ash, crude protein (AOAC, 1990) and neutral detergent fiber (NDF) and acid detergent fiber (ADF) (Van Soest et al., 1991). On the last day of each period, rumen samples were collected at 0 and 4 hours post morning feeding. Rumen samples were immediately measured for ph and then ph values were recorded. Rumen samples were prepared for ammonia nitrogen determination (Bremner and Keeney, 1965) and total microbial count (Galyean, 1989). Statistical analysis All data were statistically analyzed as a 2 2 factorial arrangement in a 4 4 Latin square design using the PROC MIXED (SAS, 1996) according to the following model : ijk = + i + j + k + l + kl + ijkl, where ijk = represents of observation from animals, = overall mean, I = fixed effect of period (i = 1-4), j = random effect of animal (i = 1-4), k = fixed effect of factor A (A = roughage sources, i = 1-2), l = fixed effect of factor B (B = enzyme supplementation, j = 1-2), kl = fixed effect of interaction and ijk = random residual. Significant differences between treatments were determined using Duncan s New Multiple Range Test (DMRT) (Steel and Torrie, 1980). 994
Table 1. Chemical compositions of experimental diet. Items Rice straw (RS) Urea-treated rice straw (UTS) concentrate Chemical composition 1 DM (%) 92.6 53.8 90.33 -------------------------- % of dry matter -------------------------- OM 89.55 88.78 CP 2.95 8.12 NDF 73.33 71.56 ADF 43.76 43.96 Ash 10.45 11.28 93.3 12.22 22.78 13.39 1 DM = dry matter; OM = organic matter; CP = crude protein; NDF = neutral detergent fiber; ADF = acid detergent fiber RESULTS AND DISCUSSION Feed intake and nutrient digestion The chemical compositions of concentrate diet, rice straw and urea-treated rice straw are shown in Table 1. Urea-treated rice straw contained 8.12%crude protein. Yuangklang et al. (2010) reported urea-treated rice straw contained 5.86%crude protein. Concentrate diet was formulated to meet nutrient requirement of buffalo according to Kearl (1982). It was clearly showed that buffalo fed RS was lower roughage intake than buffalo fed UTS (P<0.05). Enzyme supplementation was not influenced roughage intake (P>0.05). There was no interaction between roughage source and enzyme supplementation. Concentrate intake was offered at restricted feeding to ensure the rumen fermentation process. Total intake was significantly different among treatments. Buffalo fed UTS was lower in total intake than buffalo fed RS. Digestibility of DM, OM, NDF and ADF were significantly different among treatments (P<0.05). Buffalo fed RS was higher in DM digestibility than buffalo fed UTS, irrespective of fibrolytic enzyme supplementation. 6.67 995
Table 2. Feed intake and nutrient digestion of buffalo fed RS or UTS with or without fibrolytic enzyme supplementation. 1 RS UTS P-value Items - + - + SEM Ro En Ro*En Roughage intake, g/d 4.35 b 4.48 b 6.69 a 6.59 a 0.08 * ns ns %BW 1.07 b 1.08 b 1.58 a 1.63 a 0.02 * ns ns g/kgbw 0.75 47.91 b 48.62 b 71.72 a 73.45 a 0.52 * ns ns Concentrate intake, g/d 6.13 6.24 6.35 6.06 0.05 * ns ns %BW 1.50 1.50 1.50 1.50 - - - - g/kgbw 0.75 64.73 67.75 68.03 67.64 0.13 ns ns ns Total intake, kg/d 10.48 b 10.72 b 13.05 a 12.65 a 0.09 * ns ns %BW 2.56 b 2.58 b 3.08 a 3.13 a 0.01 * ns ns g/kgbw 0.75 115.4 b 116.4 b 139.8 a 140.4 a 0.51 * ns * Digestion, % of intake DM 56.65 c 59.34 b 65.33 a 66.89 a 0.56 * * * OM 58.88 c 64.38 b 67.76 ab 69.23 a 0.45 * * * NDF 51.18 c 54.23 b 58.36 ab 62.45 a 0.61 * * * ADF 48.32 c 52.66 b 55.90 ab 59.23 a 0.32 * * * 1 UTS = urea-treated rice straw; RS = rice straw; ab Means within a row with unlike superscripts differ (P<0.05). Enzyme supplementation increased DM digestibility when compared with non-enzyme supplementation. Similar with Histov et al. (2000) found that enzyme supplementation improved nutrient digestion both in rumen and intestinal sections. Khanh et al. (2012) demonstrated that fibrolytic enzyme supplementation in TMR did improve nutrient digestion in dairy cows. Rumen ph in buffalo fed RS was higher than in buffalo fed UTS. There was no influenced of enzyme supplementation on ph. The optimal level of ruminal ph was range from 6.0-7.0 (Hungate, 1967). Concentration of NH 3 -N in buffalo fed RS was lower than in buffalo fed UTS. Similar result reported by Wanapat and Pimpa (1999) demonstrated that rumen NH 3 at 17.5 mg% gave optimum rumen fermentation and maximum feed intake and digestibility of rice straw in buffalo. Total bacteria count in buffalo fed UTS was higher than in buffalo fed RS. On the other hand, total protozoa count in buffalo fed UTS was lower than in buffalo fed RS. 996
Table 3. Rumen ph, NH 3 -N and total microbial count of buffalo fed RS or UTS with or without fibrolytic enzyme supplementation. 1 RS UTS P-value Items - + - + SEM Ro En Ro*En Rumen ph 6.88 a 6.85 a 6.52 b 6.53 b 0.01 * ns ns NH 3 -N, mg% 12.42 b 12.29 b 16.73 a 16.77 a 0.24 * ns ns Total bacteria count, 10 10 cell/ml 5.73 b 5.81 b 7.15 a 7.51 a 0.13 * ns ns Total protozoa count, 10 5 cell/ml 12.88 a 12.50 a 11.10 b 11.00 b 0.20 * ns ns 1 UTS = urea-treated rice straw; RS = rice straw; ab Means within a row with unlike superscripts differ (P<0.05). Based on the experiment data, it can be concluded that supplemental fibrolytic enzyme in buffalo diet improves feed intake, nutrient digestion and rumen fermentation end products particularly when roughage source is a low quality roughage. ACKNOWLEDGMENT The authors would like to express their sincere thanks for Department of Animal Science, Faculty of Natural Resources, Rajamangala University of Technology Isan, Sakon Nakhon campus for facilities support. REFERENCES AOAC (Association of Official Analytical Chemist). 1990. Official Methods of Analysis. 15 th ed. AOAC, Washington, DC. Bremner, J.M. and D.R. Keeney. 1965. Steam distillation methods of determination of ammonium, nitrate and nitrite. Anal. Chem. Acta. 32:218. Goering, H.K. and P.J. Van Soest. 1970. Forage Fiber Analysis (Apparatus, Reagent, Procedures and some Application). Agric. Handbook. No. 397, ARS, USDA, Washington D.C. Hart, F.J. and M. Wanapat. 1992. Physiology of digestion of urea-treated rice straw in swamp buffaloes. Asian-Aust. J. Anim. Sci. 5:617. SAS. 1996. SAS/STAT User s Guide (Release 6.12). SAS Inst. Inc.,Cary, NC. Sundstol, F., N.A. Said and J. Arnason. 1979. Factors influencing the effect of chemical treatment on the nutritive value of straw. Acta Agric. Scand. 29:179. Wanapat, M. and O. Pimpa. 1999. Effect of ruminal NH3-N levels on ruminal fermentation, purine derivatives, digestibility and rice straw intake in swamp buffaloes. Asian-Aust. J. Anim. Sci. 12:904. Wanapat, M., F. Sundstol and T.H. Garmo. 1985. A comparison of alkali treatment methods to improve the nutritive value of straw. I. Digestibility and metabolizability. Anim. Feed Sci. Technol. 12:295. Wanapat, M., S. Polyorach, K. Boonnop, C. Mapato and A. Cherdthong. 2009. Effects of treating rice straw with urea or urea and calcium hydroxide upon intake, digestibility, rumen fermentation and milk yield of dairy cows. Livestock Science. 125:238. Yuangklang, C., C. Wongnen, C. Patiphan, J. Khotsakdee, T. Kandee, K. Vasupen, S. Bureenok, S. Wongsuthavas, A. Alhaidary, H.E. Mohamed and A.C. Beynen. 2010. Rumen Fermentation in Beef and Buffalo Steers Fed Native or Treated Rice Straw. Journal of Animal and Veterinary Advances, 9: 3011-3015. Zaman, M.S., and E. Owen. 1990. Effect of calcium hydroxide or urea treatment of barley straw on intake and digestibility in sheep. Small Rumin. Res. 3:237. 997