Bogor Agricultural University, *

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1 Abstract Reducing Methane (CH 4 ) Emission of Sheep Fed a Diet Supplemeted With Coconut And Palm Oil Asep Sudarman 1,*, Komang G. Wiryawan 1, & Agung Purnomoadi 2 1 Department of Nutritional Sciences and Feed Technology, Bogor Agricultural University, 2 Faculty of Animal Science, The University of Diponegoro * a_sudarman@yahoo.com An experiment was conducted to investigate the effect of polyunsaturated fatty acids supplementation on the methane (CH4) production and performance of sheep. Twenty sheep with the average body weight of 20 kg were used in this experiment. The sheep were randomly divided into four groups and each group received different ration. There were four treatments tested in this experiment i.e., R0 (basal ration + 3% coconut oil/saturated fatty acids); R1 (basal ration + 2% coconut oil + 1% crude palm oil/unsaturated fatty acids); R2 (basal ration + 1% coconut oil + 2% crude palm oil); R3 (basal ration + 3% crude palm oil). The basal ration consisted of 50% grass + 50% concentrate with nutrient content of 14% crude protein, 5% fat and 70% TDN. Experimental results showed that the supplementation of polyunsaturated fatty acids into the rations tend to reduce methane production in the rumen. The supplementation also increased the body weight gain, and digestibility of the rations, but it decreased feed consumption. It can be concluded that the addition of polyunsaturated fatty acids into the ration could improve the efficiency of energy utilization of sheep, and consequently improve the animal s performances. Keywords: coconut oil, methane, palm oil, polyunsaturated fatty acids, ruminants Introduction Methane as one of end-products of fermentation process in the rumen is continuously produced in the rumen by microorganisms such as Ruminococcus albus, R. flavefaciens, Selenomonas ruminantium and by methanogenic species from reducing CO 2 (Yokoyama and Johnson, 1993). High methane production by animal, besides contributing to potential global warming, also indicates that feed utilization efficiency is low. Ruminants lose 5-12% of the dietary energy ingested as gases (mainly CH 4 ) depending on the type of diets and the level of intake (Reid et al., 1980). 361

2 To inhibit the formation of methane the addition of oil into diet seems to be more prospectus will not leave residues in animal products. Supplementation of unsaturated oil into ruminant diet perhaps will reduce methane emission from animals. Unsaturated oils may serve as an effective H sink in the rumen by binding H (Byers and Schelling, 1993). Palm oil contains 50% unsaturated fatty acids (APOC). Therefore it is a good source of unsaturated fatty acids. The objective of this experiment was to investigate the effect of polyunsaturated fatty acids (palm oil) supplementation into ruminant diet on the ruminal methane emission and the performance of the sheep. Materials and Methods The experiment was conducted in vivo using twenty sheep with average body weight of ± 1.94 kg. The animals were randomly divided into four groups consisting of five animals each group in completely randomized design. Each group of animals received different ration, and the length of animal experiment was four months. The basal ration consisted of 50% grass + 50% concentrate with nutrient content of 14% crude protein, 5% fat and 70% TDN. Four levels of oil supplementation were tested in this experiment, i.e., R0 (basal ration + 3% coconut oil/saturated fatty acids); R1 (basal ration + 2% coconut oil + 1% crude palm oil/unsaturated fatty acids); R2 (basal ration + 1% coconut oil + 2% crude palm oil); R3 (basal ration + 3% crude palm oil). Parameters measured including: rumen methane production, rumen fermentation products, feed consumption, body weight gain, feed conversion and nutrient digestibility (dry matter, organic matter, and crude protein, crude fiber). Methane gas was determined using a closed-circuit respiration chamber. Meanwhile, nutrients digestibility was determined using total collection method. Concentration of ruminal VFA was measured using steam destilation method, and concentration of ruminal NH 3 was measured using Conway micro-diffusion method (General Laboratory, 1966) Data were subjected to ANOVA (Steel and Torrie, 1980) using SPSS computer program. Results and Discussion Feed Intake and Body Weight Gain Body Weight Gain Addition of unsaturated fatty acids gave inconsistent results of feed (dry matter) intake of sheep (Figure 1) and statistically was not different (P>0.05) among the treatments. Sheep fed R2 had the highest dry matter intake. It is often reported that unsaturated oil is more toxic to the microbial rumen than saturated oil (Henderson, 1973), and inhibits growth of microbes (Palmquist and Jenkins, 1980). Wachira et 362

3 al. (2002) reported that feeding unprotected fish oil (unsaturated oil) to sheep caused a decrease in feed intake and body weight gain. This agrees with the present results, especially with the results of sheep fed R1 and R3. (a) (b) Figure 1. Effects of additional fat into the diets on (a) dry matter intake and (b) body weight gain of sheep. (R0: basal ration + 3% coconut oil/saturated fatty acids; R1: basal ration + 2% coconut oil + 1% crude palm oil/unsaturated fatty acids; R2: basal ration + 1% coconut oil + 2% crude palm oil; R3: basal ration + 3% crude palm oil). Addition of unsaturated fatty acids improved body weight gain of sheep (Figure 1), eventhough statistically was not different. The highest body weight gain was achieved by animals fed R1 (Basal diet + 2% saturated oil + 1% unsaturated oil), followed by R3, R2 and R0. Body weght weight gan) gain) s is nfluenced influenced by level of feed intake and characteristics of feed. Except sheep fed R2, those sheep fed unsaturated oil (R1 and R3) had lower feed intake than those fed saturated oil (R0). This may indicated that higher body weight gain of sheep fed R1, R2, and R3 was due to the supplementaton tion of unsaturated ol oil by mprovng improving feed effcency efficiency (low methane production). Ruminal VFA and N-NH 3 Ruminal VFA concentration was not significantly (P>0.05) affected by the treatments and it ranged from 65 to 120 mm (Figure 2). This range is in normal concentration and is sufficient to support rumen microbial growth and to supply energy for the animals. There is no negative effect of unsaturated oil supplementation on the carbohydrates fermentation in the rumen, and yet the R3 (ration containing 3% unsaturated oil) had the highest VFA concentration in the rumen. Other research results also showed that total volatile fatty acid concentrations was not affected by source and amount of oil (Ohajuruka, et al., 1991). The concentration of N-NH 3 was in normal range (4 18 mm) and enough to support rumen microbial activities and to synthesize rumen microbial protein. This 363

4 result also means that protein degradation in the rumen was not affected by the supplementation of unsaturated oil into the rations. This is in line with Ohajuruka, et al. (1991) who reported that ammonia-n was not affected by source and amount of oil. Figure 2. Effects of additional fat into the diets on (a) ruminal VFA and (b) ruminal N-NH 3. (R0: basal ration + 3% coconut oil/saturated fatty acids; R1: basal ration + 2% coconut oil + 1% crude palm oil/unsaturated fatty acids; R2: basal ration + 1% coconut oil + 2% crude palm oil; R3: basal ration + 3% crude palm oil). Feed Digestibility Effect of oil addition into the diet on feed digestibility was shown in Figure 3. Feed digestibility had tendency to increase by the addition of unsaturated oil into the diet. Eventhough it was not significantly different. In contrast, crude fiber digestibility reduced by the addition of unsaturated oil into the rations. Oil supplementation may decrease forage digestibility by disturbing normal condition of rumen microbe when given at level above 5% of the ration (Preston and Leng, 1987). This is more pronounced with unsaturated oil, because unsaturated oil is more toxic to the microbial rumen than saturated oil (Henderson, 1973). The increase in feed digestibilities in this experiment indicated that the addition of 3% unsaturated oil into sheep rations did not cause negative effect on the fermentation process in the rumen. Methane Production Unsaturated oil addition into the ration tend to lower methane production by sheep (Figure 4), eventhogh statistically was not different. Unsaturated oils may also serve as an effective H sink in the rumen by consuming H (Byers and Schelling, 1993). Therefore, methane formation competed with the saturation of unsaturated oils for H sink. It implies that when dietary unsaturated oils are given to ruminant, in line with H availability in the rumen, saturation occurs and methane production decreases as shown by the results in this experiment (R1, R2 and R3). The results are supported by Chikunya et al. (2004) who reported that biohydrogenation in the 364

5 rumen of linoleic acid (18:3 n-6; %), linolenic acid (18:3 n-3; %), docosahexaenoic acid (22:6 n-3; 91 %) and EPA (20:5 n-3; 92 %) was extensive. Figure 3. Effects of additional fat into the diets on feed digestibility (%) of sheep: (a) dry matter digestibility, (b) organic matter digestibility, (c) crude protein digestibility, and (d) crude fiber digestibility. (R0: basal ration + 3% coconut oil/saturated fatty acids; R1: basal ration + 2% coconut oil + 1% crude palm oil/unsaturated fatty acids; R2: basal ration + 1% coconut oil + 2% crude palm oil; R3: basal ration + 3% crude palm oil) Figure 4. Effects of additional fat into the rations on methane (CH 4 ) production of sheep, (R0: Basal diet + 3% saturated fat; R1: Basal diet + 2% saturated fat + 1% unsaturated fat; R2: Basal diet + 1% saturated fat + 2% unsaturated fat; R3: Basal diet + 3% unsaturated fat). 365

6 Conclusion The supplementation of polyunsaturated fatty acids into sheep rations improved feed utilization and efficiency indicated by higher body weight gain and feed digestibility, and lower methane production. Addition level of 3% of polyunsaturated fatty acids did not cause negative effect but it is not sufficient to show significant results on the sheep performance. Acknowledgement We would like to thanks the OGFICE (Osaka Gas Foundation of International Cultural Exchange) that provided the financial grant for conducting this research. References APOC (American Palm Oil Council). html#17. [4 Januari 2012]. Byers, F.M. & G.T. Schelling Lipids in ruminant nutrition. In The Ruminant Animal Digestive Physiology and Nutrition. Ed. DC Church. Waveland Press, Inc. Illinois, USA. Chikunya, S., G. Demirel, M. Enser, J.D. Wood, R.G. Wilkinson, & L.A. Sinclair Biohydrogenation of dietary n-3 PUFA and stability of ingested vitamin E in the rumen, and their effects on microbial activity in sheep. Br J Nutr. 91: General Laboratory Methods of Determination of Urea. Madison. Dept. of Dairy Sci., University of Winconsin. Henderson, C The effects of fatty acids on pure cultures of rumen bacteria. J. Agric. Sci. (Camb.). 81: 107. Ohajuruka, O.A., Z.G. Wu and D.L. Palmquist Ruminal metabolism, fiber, and protein digestion by lactating cows fed calcium soap or animal-vegetable oil. J. Dairy Sci. 74: Reid, J. T., O. D. White, R.Anrique, and. A. Fortin, Nutritional energetics of livestock: some present boundaries of knowledge and future research needs. J. Anim. Sci. 51: Steel, R. G. D. & J. H. Torrie Principles and Procedures of Statistics: A Biometric Approach. McGraw-Hill Book Co., New York. Wachira, A.M., L.A. Sinclair, R.G. Wilkinson, M. Enser, J.D. Wood, & A.V. Fisher Effects of dietary oil source and breed on the carcass composition, n-3 polyunsaturated fatty acid and conjugated linoleic acid content of sheep meat and adipose tissue. Br J Nutr. 88:

7 Yokoyama, M.T. & K.A. Johnson Microbiology of the rumen and intestine. in The Ruminant Animal Digestive Physiology and Nutrition. Ed. DC Church. Waveland Press, Inc. Illinois, USA. 367