SHORT COMMUNICATION: Energy values and apparent total tract digestibility coefficients of copra meal and palm kernel meal fed to growing pigs

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1 SHORT COMMUNICATION: Energy values and apparent total tract digestibility coefficients of copra meal and palm kernel meal fed to growing pigs Y. D. Jang 1 and Y. Y. Kim 2 School of Agricultural Biotechnology, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul , Republic of Korea. Received 11 February 2013, accepted 22 July Published on the web 1 August Can. J. Anim. Sci. Downloaded from by on 08/21/16 Jang, Y. D. and Kim, Y. Y SHORT COMMUNICATION: Energy values and apparent total tract digestibility coefficients of copra meal and palm kernel meal fed to growing pigs. Can. J. Anim. Sci. 93: To determine energy values and coefficients of apparent total tract digestibility (CATTD) of copra meal (CM) and palm kernel meal (PKM), 24 growing pigs were fed a cornsoybean meal basal diet and the basal diet replaced by 300 g kg 1 of either CM or PKM. Copra meal had higher CATTD of gross energy (12%), dry matter (DM; 13%), neutral detergent fiber (16%), acid detergent fiber (23%), and crude fiber (79%; PB0.05) than PKM. Copra meal had a slightly higher digestible energy (DE) value than PKM (14.08 vs MJ kg 1 DM; P0.067), but metabolizable energy (ME; vs MJ kg 1 DM), net energy (7.97 vs MJ kg 1 DM), and ME:DE ratio did not differ between CM and PKM. Therefore, compared with PKM, CM can be a better source of dietary energy in swine diets as evidenced by higher CATTD of energy and fiber components. Key words: Copra meal, palm kernel meal, growing pig, energy value, apparent total tract digestibility Jang, Y. D. et Kim, Y. Y BRE` VE COMMUNICATION : Valeurs énerge tiques et coefficients de digestibilite apparente dans le tube digestif complet du tourteau de copra et du tourteau de palmiste donne s aux porcs en croissance. Can. J. Anim. Sci. 93: Pour de terminer les valeurs e nerge tiques et les coefficients de digestibilite apparente dans le tube digestif complet (CATTD «coefficients of apparent total tract digestibility») du tourteau de copra (CM «copra meal») et du tourteau de palmiste (PKM «palm kernel meal»), 24 porcs en croissance ont rec u une die` te de base de tourteau de soya-maı s et une diète de base remplace e par 300 g kg 1 soit de CM ou de PKM. Le tourteau de copra avait des CATTD plus e levés d e nergie brute (12 %), de matie` res se` ches (DM «dry matter»; 13 %), de fibres au de tergent neutre (16 %), de fibres au de tergent acide (23 %), et des fibres brutes (79 %; PB0,05) que la PKM. Le tourteau de copra avait une valeur d e nergie digestible (DE «digestible energy») le ge` rement plus éleve e que la PKM (14,08 c. 13,01 MJ kg 1 DM; P0,067), mais l e nergie me tabolisable (ME «metabolizable energy») (ME; 13,33 c. 12,83 MJ kg 1 DM), l e nergie nette (7,97 c. 7,36 MJ kg 1 DM), et le ratio ME:DE ne diffe raient pas entre CM et PKM. La CM peut donc eˆtre une meilleure source d e nergie alimentaire dans les diètes porcines que la PKM, selon les résultats supérieurs en CATTD d e nergie et de composantes en fibres. Mots clés: Tourteau de copra, tourteau de palmiste, porc en croissance, valeur énerge tique, coefficients de digestibilite apparente dans le tube digestif complet Copra meal (CM) and palm kernel meal (PKM), which are co-products of oil extraction from coconut and palm nut, respectively, are available as livestock feedstuffs in tropical regions. Copra meal and PKM generally contain crude protein (CP) that ranges from 150 to 260 g kg 1 and from 130 to 220 g kg 1, respectively, and less than 40 g kg 1 ether extract (EE; Sundu and Dingle 2003). Because of their moderate amount of protein, these feedstuffs have been considered supplemental protein sources in swine diets. However, CM and PKM contain high levels of non-starch polysaccharides (NSP) that cannot be hydrolyzed by enzymes produced in the gastrointestinal tract of monogastric animals. 1 Current address: University of Kentucky, Lexington, KY. 2 Corresponding author ( yooykim@snu.ac.kr). Bach Knudsen (1997) reported NSP content in CM and PKM was 422 and 466 g kg 1, respectively. The primary NSP in CM and PKM is b-mannan, which constitutes 250 to 350 g kg 1 in CM and PKM on a dry matter (DM) basis, respectively (Sundu and Dingle 2003). It has previously been reported that the metabolizable energy (ME) of CM is MJ kg 1 (Thorne et al. 1989) and that of PKM is MJ kg 1 (Agunbiade et al. 1999). However, energy values and nutrient content of CM and PKM are highly variable due to origin, environment, feed processing, Abbreviations: AA, amino acid; ADF, acid detergent fiber; CATTD, coefficient of apparent total tract digestibility; CF, crude fiber; CM, copra meal; CP, crude protein; DE, digestible energy; DM, dry matter; EE, ether extract; GE, gross energy; ME, metabolizable energy; NDF, neutral detergent fiber; NE, net energy; NSP, non-starch polysaccharide; PKM, palm kernel meal Can. J. Anim. Sci. (2013) 93: doi: /cjas

2 518 CANADIAN JOURNAL OF ANIMAL SCIENCE and oil extraction methods (Thorne et al. 1989; Sundu and Dingle 2003). The dietary energy values and nutrient digestibility of CM and PKM should be determined for proper formulation of these feedstuffs in swine diet. The objective of the experiment was to determine energy values and coefficients of apparent total tract digestibility (CATTD) of relevant nutrients in CM and PKM fed to growing pigs. The animals used in the experiment were cared for under guidelines comparable to those described by the Canadian Council on Animal Care. A total of 24 growing barrows [(YorkshireLandrace) Duroc; average body weight, kg] were used in the study. Pigs were housed individually in metabolic crates ( m 2, height 0.60 m) in a naturally ventilated facility at room temperature. Pigs were allotted to be fed one of three test diets based on initial body weight as a randomized complete block design. Because of low diet palatability, 1000 g of daily feed allotment was divided into two equal meals and provided at 0700 and 1900 with a small amount of water. Between meals, pigs had ad libitum access to water. The basal diet was cornsoybean meal based formulated to meet National Research Council (1998) requirements. Corn, soybean meal, and crystalline amino acid (AA) in the basal diet were replaced by 300 g kg 1 of either CM or PKM (Tables 1 and 2). The experiment lasted 12 d; the first 7 d were for diet adaptation and the last 5 d for fecal and urine collection. Chromic oxide was added at 5 g kg 1 to the morning meal fed on day 8 and evening meal fed on day 12 as an indigestible marker. The total collection method was used to determine CATTD. Fecal collection was initiated when the marker first appeared in the feces and was terminated when the marker was last present in the feces, as described by Adeola (2001). Urine collection commenced on day 1 at 1900 and ceased on day 5 at Feces and urine were collected once daily at Urine was collected in plastic buckets containing 50 ml Table 1. Analyzed nutrient composition of copra meal and palm kernel meal (920 g kg 1 DM basis) z Item (g kg 1 ) y Copra meal Palm kernel meal GE (MJ kg 1 ) CP EE NDF ADF CF Starch crude fiber. y Dry matter content of CM and PKM was and g kg 1, respectively (as-fed). Table 2. composition and analyzed gross energy and nutrient content of experimental diets (g kg 1, as-fed basis) z Diet Item Basal Copra meal Palm kernel meal Corn Soybean meal (450 g kg 1 CP) Copra meal Palm kernel meal L-LysineHCl (780 g kg 1 ) DL-methionine (990 g kg 1 ) Limestone Dicalcium phosphate Vitamin mix y Mineral mix x Salt Total GE (MJ kg 1 ) DM CP EE NDF ADF CF Starch crude fiber. y Provided the following per kilogram of diet: vitamin A, 8000 IU; vitamin D 3, 2000 IU; vitamin E, 35 IU; vitamin K, 3 mg; vitamin B 2, 3 mg; vitamin B 12,10mg; Ca pantothenate, 10 mg; biotin, 100 mg; and niacin, 30 mg. x Provided the following per kilogram of diet: Fe, 100 mg; Mn, 40 mg; Zn, 50 mg; Cu, 150 mg; Se 0.3 mg; and I, 1 mg. of 3 M sulfuric acid to prevent ammonia evaporation. Feces were weighed, pooled, sealed in plastic bags, and frozen at 208C until analysis. At the end of experiment, fecal samples were thawed and dried in a forcedair drying oven at 608C for 72 h. Feces were then ground through a 1-mm screen using a Wiley mill (Model 3, Arthur H. Thomas Co., PA) for chemical analysis. When urine was collected, distilled water was added to the urine samples to reach 4000 ml, then a 100-mL aliquot was taken and stored at 208C. At the end of the experiment, urine samples were thawed, mixed within an animal, and sub-sampled for analysis. Chemical analyses of feedstuffs, diets, fecal and urine samples were conducted in duplicate. Feedstuffs (CM and PKM), diets, and fecal samples were analyzed for DM by oven drying at 1058C for 3 h [935.29; Association of Official Analytical Chemists (AOAC) 2005]. The samples were analyzed for EE by Soxhlet extraction (920.39; AOAC 2005). Neutral detergent fiber (NDF), acid detergent fiber (ADF), and crude fiber (CF) were analyzed according to the methods of van Soest et al. (1991) using an ANKOM A2000 Fiber Analyzer (ANKOM Technology Corporation, NY). Feedstuffs, diets, fecal and urine samples were analyzed for gross

3 JANG AND KIM * ENERGY VALUE OF COPRA AND PALM KERNEL MEALS 519 Can. J. Anim. Sci. Downloaded from by on 08/21/16 energy (GE) by bomb calorimeter (Parr 1261, Parr Instruments, IL). To measure the GE of urine, 5 g of dried cellulose was added to each of the 15-mL urine samples, and then freeze-dried for 24 h. Gross energy of urine was calculated by subtracting GE value of cellulose from the GE value of the urine and cellulose mixture. Crude protein was analyzed using the Kjedahl method (984.13; AOAC 2005). Starch was analyzed using the Ewers polarimetric method (European Economic Community 1972). The CATTD of GE and nutrients in the diets was determined using the total collection method. The CATTD of GE and nutrients in CM or PKM was determined using the difference method (Adeola 2001) with the corn-based diet as the basal diet using the following equation: CATTD feedstuff [CATTD t (CATTD b C y )]=C i where CATTD feedstuff is the CATTD of GE or a nutrient in the test feedstuff (CM or PKM), CATTD t is the CATTD of GE or a nutrient in the test diet. CATTD b is the CATTD of GE or a nutrient in the basal diet. C y is the contribution of GE or a nutrient from energy- and AA-yielding ingredients to the test diet, and C i is the contribution of GE or a nutrient from the test feedstuff to the test diet. The C y and C i of each nutrient were calculated using following equations: N y N b =0:9764 C y (N y 0:67834)=N t C i 1C y where, N y is GE or a nutrient content in energy- and AA-yielding ingredients, N b is GE or a nutrient content in the basal diet, and N t is GE or a nutrient content in the test diet. The digestible energy (DE) and ME for CM and PKM were estimated using following equation: E feedstuff (E t 0:67834E y )=0:300 where, E feedstuff is an energy value (DE or ME) of test feedstuff, E t is an energy value of test diet, and E y is an energy value of energy- and AA-yielding ingredients from the basal diet. Net energy (NE) for CM and PKM was estimated using Eqs. 18 of the National Research Council (2012) using the estimated DE and nutrient content. Further correction was conducted to calculate DE, ME, and NE in the test feedstuffs on a DM basis. Data for energy values and CATTD of GE and nutrients in the test feedstuffs were analyzed by ANOVA using the PROC MIXED of SAS software (SAS Institute, Inc., Cary, NC). The model included the effect of the feedstuff (CM vs. PKM) as a fixed effect, pen, and replicate as random effects. Least squares means were separated using the PDIFF option of SAS saftware. Pig was considered the experimental unit. The alpha level used for the determination of significance was 0.05; trend was considered P0.05 and PB0.10. Copra meal and PKM were different in energy and nutrient composition, particularly in CP and fiber components such as NDF, ADF, and CF (Table 1). Palm kernel meal contained greater GE (2%) and content of EE (12%), NDF (10%), ADF (21%), and CF (33%) but less CP (28%) content than CM. Starch content was very low in both feedstuffs. The CATTD of GE (12%), DM (13%), NDF (16%), ADF (23%), and CF (79%) in CM was higher (PB 0.05) than in PKM, whereas CATTD of EE tended to be higher (P0.100) for PKM than for CM (Table 3). The CM and PKM were not different in CATTD of CP. The DE value tended to be higher in CM than in PKM (P 0.067) but ME, NE, and ME:DE ratio did not differ between CM and PKM. The chemical compositions of the CM and PKM fed in this study were similar to those reported by National Research Council (2012). However, the NDF and EE contents of CM were much greater, but the CP and CF contents were less than those reported by Sauvant et al. (2004), whereas PKM contained less NDF, ADF, CF, and EE than reported by Sauvant et al. (2004). Because the CM and PKM fed in this study were produced by solvent extraction, both feedstuffs contained low EE content. Copra meal contained a greater content of CP, but less fiber components such as NDF, ADF, and CF than PKM, which agrees with previous publications (Sauvant et al. 2004; National Research Council 2012). Starch content was similar and low (6.5 g kg 1 ) in both Table 3. Coefficient of apparent total tract digestibility (CATTD) and energy values in copra meal and palm kernel meal, estimated by difference (DM basis) z Variable y Copra meal Palm kernel meal SEM x P value CATTD GE DM CP EE NDF ADF CF B.0001 Energy values (MJ kg 1 ) GE DE ME NE w ME:DE crude fiber; DE, digestible energy; ME, metabolizable energy; NE, net energy. y Least squares means based on eight observations per feedstuff. x Standard error of mean. w NE(0.70DE)(1.61EE)(0.48starch) (0.91CP) (0.87 ADF), Eqs. 18 in National Research Council (2012); The unit is g kg 1 DM for nutrients and kcal kg 1 for energy values. After calculation, the unit for NE was converted to MJ kg 1 DM.

4 520 CANADIAN JOURNAL OF ANIMAL SCIENCE CM and PKM, which is in agreement with Bach Knudsen (1997), who reported coconut cake and palm cake contained 10 and 11 g kg 1 of starch, respectively. The CATTD of GE, DM, and fiber components in CM was higher than that in PKM, but the CATTD of CP was similar between test feedstuffs. In a previous study, Sundu et al. (2005) reported higher digestibility of DM and CP in CM than PKM in broilers. However, there is limited information for pigs about the direct comparison of nutrient digestibility and feeding values between CM and PKM, and the literature lacks evidence that CM has higher fiber digestibility than PKM. In the current study, greater digestibility of GE and DM in CM compared with PKM could have resulted from greater digestibility of fiber components in CM than PKM. The NDF, ADF, and CF contents in the test feedstuffs were analyzed, but the composition of NSP was not measured in this study. In spite of this, the higher fiber digestibility in CM compared with PKM might be attributed to ingredient properties and levels of NSP in these feedstuffs. Palm kernel meal contained more NDF, ADF, and CF than CM (Table 1). It is known that the NSP in PKM consists of 780 g kg 1 insoluble linear mannan with a small amount of galactomannan, 30 g kg 1 arabinoxylan, 30 g kg 1 glucuronoxylan, and 120 g kg 1 cellulose in total NSP (Du sterho ft et al. 1992). Copra meal consists of 260 g kg 1 of linear mannan and 610 g kg 1 of galactomannan in total NSP (Balasubramaniam 1976). Sundu et al. (2005) reported CM had a higher water-holding capacity than PKM (4.14 and 2.94 g water g 1 feed for CM and PKM, respectively). In general, soluble NSP is more fermentable compared with insoluble NSP because soluble NSP increases the intestinal viscosity and microbial activity in the gastrointestinal tract resulting in the increase in fiber degradability (De gen et al. 2007). These explanations could be applied to the current study. The CATTD of EE in PKM tended to be higher than that in CM. Soluble NSP had a greater influence to depress fat digestibility than insoluble NSP (De gen et al. 2007). The different solubility of NSP between CM and PKM might have been influenced by this effect. The estimated DE, ME, and NE values in this study were in good agreement with values reported by National Research Council (2012). This result could be explained by the chemical compositions of CM and PKM fed in this study being close to those reported by the National Research Council (2012). However, the energy values of CM and PKM in this study were much greater than those reported by Sauvant et al. (2004), reflecting different chemical compositions. In the current study, a slightly higher DE value was observed in CM than in PKM. This could be attributed to the higher GE digestibility and lower DM content in CM compared with PKM. However, the ME value was similar between CM and PKM. A numerically lower ME:DE ratio in CM than in PKM may contribute to a greater reduction from DE to ME in CM than in PKM, resulting in no significant difference in ME between these two feedstuffs. Noblet and van Milgen (2004) reported the ME:DE ratio decreased as protein content in the diet was increased because urinary output of N and energy was increased by increasing protein level. Therefore, the lower ME:DE ratio of CM could result from higher a CP content in CM (216.8 g kg 1 ) than in PKM (160.3 g kg 1 ; Table 1). In conclusion, CM and PKM have similar ME and NE values for growing pigs and have potential to be fed in swine diets, as shown by the moderate protein content and energy values. Because of the higher digestibility, not only of fiber components, but also of GE and DM in CM than in PKM, CM could be a better source of energy in swine diets. 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Acta Agric. Scand. A-AN. 57: 19. Du sterho ft, E. M., Posthumus, M. A. and Voragen, A. G. J Non-starch polysaccharides from sunflower (helianthus annuus) meal and palm kernel (Elaeis Guineensis) mealinvestigation of the structure of major polysaccharides. J. Sci. Food Agric. 59: European Economic Community Analytical determination of starch. Page 7 in Official Journal of European Communities. Publ. No Eur. Econ. Community, Brussels, Belgium. Noblet, J. and van Milgen, J Energy value of pig feeds: Effect of pig body weight and energy evaluation system. J. Anim. Sci. 82: E229E238. National Research Council Nutrient requirements of swine. 10th rev. ed. National Academy Press, Washington, DC. pp National Research Council Nutrient requirements of swine. 11th rev. ed. National Academy Press, Washington, DC. pp. 260, 304. Sauvant, D., Perez, J.-M. and Tran, G Tables of composition and nutritional value of feed materials. 2nd rev. ed. 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5 JANG AND KIM * ENERGY VALUE OF COPRA AND PALM KERNEL MEALS 521 Sundu, B. and Dingle, J Use of enzymes to improve the nutritional value of palm kernel meal and copra meal. Pages 115 in Proc. Queensland Poultry Science Symposium, Gatton, Queensland, Australia. Sundu, B., Kumar, A. and Dingle, J Comparison of feeding values of palm kernel meal and copra meal for broilers. Page 28A in Proc. Recent Advances in Animal Nutrition in Australia, University of New England, New South Wales, Australia. Thorne, P. J., Wiseman, J., Cole, D. J. A. and Machin, D. H The digestible and metabolizable energy value of copra meals and their prediction from chemical composition. Anim. Prod. 49: van Soest, P. J., Robertson, J. B. and Lewis, B. A Methods for dietary fiber, neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition. J. Dairy Sci. 74: