Research Note Nutritive value of meat and bone meal for growing pigs Kirsi Partanen and Matti Näsi Partanen, K. & Näsi, M. 1994. Nutritive value of meat and bone meal for growing pigs. Agricultural Science inFinland 3; 449-455. (Department of Animal Science, PO Box 28, FIN-00014 University of Helsinki, Finland.) Six barrows, with an average initial body weight of 88 kg, were used in a digesti- bility and balance experiment to study the nutritive value of meat and bone meal (MBM). The MBM, which contained 478 g crude protein and 322 g ash/kg dry matter (DM), was included in barley-based diets at two levels: 100 and 200 g/kg. The experiment was conducted according to a two-period reversal design. The apparent digestibilities of organic matter, crude protein and crude fat in the MBM were 0.910, 0.909 and 0.730, respectively. The MBM was calculated to contain 434 g digestible crude protein, 14.26 MJ metabolizable energy and 8.82 MJ net energy/kg DM. The efficiency of nitrogen utilization decreased with an increasing MBM supply. Due to relatively high mineral intakes, the apparent digestibilities of calcium and phosphorus remained low. Key words: digestibility, nitrogen balance, minerals Introduction Meat and bone meals are by-products of the slaughtering and meat processing industry. They are good sources of protein, energy and minerals, and are, therefore, useful as animal feed (Miller and De Boer 1988). The Finnish rendering plants produce approximately 29 million kg of meat and bone meal annually (Sirén, personal communica- tion), a large proportion of which is used in pig diets. The results of feeding experiments have shown that replacement of soya bean meal with in- creasing levels of meat and bone meal causes a reduction in average daily gain and feed conver- sion efficiency (Alaviuhkola 1989, 1992), al- though the calculated nutrient supply, based on the digestibilities and energy values reported in feed tables (Salo et al. 1990) remained the same. As indicated by several authors (Just et al. 1982, Knabe et al. 1989, Bruyer et al. 1990, Skilton et al. 1991), meat and bone meal is not a single product but a variety of different products and, hence, actual nutrient contents and their digestibilities can differ considerably from those given in feed tables. Therefore, re- duced performance may result from inappropri- ate nutrient values being ascribed to the prod- uct. The digestibility of protein, the amino acid content and their availability, in particular, can vary considerably between different meat and bone meals (Batterham et al. 1986,Knabe et al. 1989). The aim of this preliminary study was to de- termine the nutritive value of meat and bone meal for pigs. A sample of meat and bone meal (MBM) was obtained from a rendering plant which has a dry rendering system with mechanical removal of fat after rendering. The raw material was a mixture of cattle and pig offal, and bones. The sample represented an average composition of the MBM produced by the plant. 449 Agricultural Science in Finland 3 (1994) https://www.c-info.fi/en/info/?token=yR-jlZ2ze9EVr44I.kvzDVWNHYXen3ukAalOz8A.izF--jfY37DdxgV3eWdX1iGmOpH52TDxFWzmI4Vf5y0J-TcXTDgJkiHQwtteVaZfo0ohxp1-0gKYurJ13UBRPB-OcUV4qHF65e1x93oCZ_jMaGtsAxEGgP4UpL3TWZ7IQMhoYJa2pcUftutyuVsVT-TwCpfZU1hVOdVF7vfhXHQObfNB_mE1A7frT07Ll3QY_akES8u2ODcNmy0zPOBjsI3A0urgT5BFsXywnwEh6OpV3p5c3KR_DtD-gHqomFTkaOkrNxdMz9wsFDFFrRY0zlfQ10a_zObHEA Agricultural Science in Finland 3 (1994) Material and methods The digestibility and balance experiment was con- ducted with six Large White x Landrace finish- ing barrows using a two-period reversal design. The experimental diets were composed as fol- lows: diet A contained 800 g barley, 100 g barley starch and 100 g MBM/kg, and diet B contained 800 g barley and 200 g MBM/kg. The diets were supplemented with 1.2 (diet A) or 1.4 (diet B) g/kg of trace mineral mixture with the follow- ing mineral content per g: 13 mg Fe, 46 mg Zn, 13 mg Mn, 13 mg Cu and 0.06 mg Se. The pigs were also given a vitamin solution which added the following vitamins per kg of diet: 5000 IU vitamin A, 500 IU D,, 15 mg E, 1 mg K,, I mg B r 2mg 8,, 2mg 86,B 6, 0.0075 mg B |2, 0.025 mg biotin, 5 mg pantothenic acid and 10 mg nicotin- ic acid. The pigs were kept in metabolism cages throughout the experiment. The experiment com- prised two 10-day periods, and faeces were col- lected for five consecutive days, starting on day 6. The daily ration (2.7 kg feed) was divided into two equal meals and mixed with water (1 water: 1 feed, w/w). Water was available ad libitum be- tween the meals. The average initial body weight of the pigs was 88.0 (± 5.9) kg and the average final weight 112.5 (± 7.3) kg. The feed ingredients were analyzed for ash, crude fat (CF), nitrogen (N), amino acids, calci- um (Ca), phosphorus (P) and magnesium (Mg). Total faeces were collected daily, stored at -18°C until the end of the collection period, thawed, mixed, sampled, and analyzed for dry matter (DM). Faeces were analyzed for ash, CF, Ca, P and Mg. The samples were dried at 60°C for 72 hours prior to the chemical analyses, ex- cept for N, which was analyzed from fresh sam- ples. Urine was collected daily into 40 ml of 10 N H,S04 , sampled and stored at 4°C. At the end of the collection period, the samples were pooled on an animal basis and analyzed for N, urea N, Ca, P and Mg. Ash, CF and N analyses were performed ac- cording to the methods described by AOAC (1984). Crude protein (CP) was calculated as Kjel- dahl N x 6.25. CF was determined after hydroly- sis with 4 N HCI. Amino acid analyses were per- formed by ion-exchange chromatography after hydrolysis in 6 N HCI for 23 h. For methionine and cystine analyses, the samples were oxidized by performic acid prior to acid hydrolysis. The urea N content was analyzed with a Gilford 3000 Auto Analyzer. P was determined after dry ash- ing by colorimetry using the vanadomolybdate procedure (Tayssky and Shorr 1953), and Ca and Mg were measured by atomic absorption spec- troscopy. The data were subjected to a least square ana- lysis of variance (Snedecor and Cochran 1989) using the model: Y... = u + A + P + T. + e... ijk i j k ijk where A, P and T are the effects of animal, peri- od and treatment, respectively. To calculate the digestibility coefficients of nutrients in the MBM, the data were inserted into the multiple regres- sion equation Y = aX, + bX 2 in which Y is the total amount of nutrient digest- ed from the ratio (g/d), X, and X 2 are the amounts of nutrient consumed from barley/MBM (g/d), and a and b are the digestible fractions of nutri- ent in barley/MBM, respectively (Schneider and Flatt 1975). Barley starch was excluded from the equation because it was assumed to be fully digestible (Graham et al. 1986, 1989). The me- tabolizable (ME) and net energy (NE) values of the MBM were calculated according to Andersen and Just (1983), while the value for net energy in fattening feed units (FU = 0.7 starch equiva- lents) was calculated as described by Salo et al. (1990). Results and discussion Meat and bone meal is the rendered product from inedible slaughter offal and bones. The raw ma- terials incorporated into the meal may also in- 450 Research Note Table I, Chemical composition of feed ingredients. Table 2. Amino acid composition of meat and bone meal, g/100 g crude protein. Feed ingredient Meat Barley Barley Trace and bone starch mineral Alanine 7.1 Leucine 5.5 mea' mixture Arginine 6.7 Lysine 4.1 Aspartic acid 6.7 Methionine 1.1Dry matter, g/kg 967 879 863 964 Cystine ~2 Phenylalanine 3.2 Content in DM, g/kg: Glutamic acid 11.0 Serine 4.7Crude protein 478 115 4 1 Glycine 20.8 Threonine 3.1 Crude fat 157 32 0 0 Histidine 1.3 Tyrosine 1.9 Ash 322 26 2 922 Isoleucine 2.6 Valine 4.2 Ca 118.7 0.7 0.2 303.1 P 55.9 4.1 0.3 0.1 Mg 2.3 1.3 0.06 7.3 elude hide trimmings, heads, feet and blood. The nutritive value of meat and bone meal is mainly dependent on raw material composition and processing conditions (Just et al. 1982, Haugen et al. 1985, Batterham et al. 1986, Knabe et al. 1989, Bruyer et al. 1990, Skilton et al. 1991). The chemical composition of the MBM sample analyzed in the present study (Table 1)is in agree- ment with the results reported by others (Just et al. 1982, Knabe et al. 1989,Bruyer et al. 1990). Finnish feed tables (Salo et al. 1990)give a some- what lower fat content (90 g CF/kg DM) for meat and bone meal than that measured in the present experiment. The MBM sample was obtainedfrom a plant which removes the fat mechanically after rendering, which explains the somewhat higher fat content. The contents of essential amino acids (Table 2) are within the wide range of values (2.9-7.4 g/ 100 g CP) reported for meat and bone meal in the literature (Just et al. 1982. Bruyer et al. 1990, Salo et al. 1990, Skilton et al. 1991). Lysine is the first limiting amino acid in barley-based diets (Fuller et al. 1979) and, therefore, its amount in a protein supplement is very important. The pigs ate the feed without difficulty and their health remained good throughout the exper- iment. The average daily weight gain was 979 g. The faecal digestibility of CP and CF in- creased (p < 0.05) with an increasing MBM supply, whereas that of organic matter (OM, p < 0.05) and ash (p = 0.053) decreased (Table 3). The apparent digestibility coefficients calcu- lated for nutrients in the MBM were: OM 0.910, CP 0.909 and CF 0.730. Based on the deter- mined digestibility coefficients, the MBM was calculated to contain 434 g digestible CP, 14.26 MJ ME and 8.82 MJ NE/kg DM. The energy value in feed units was 0.98 FU/kg DM. The digestibility coefficients and energy value of the MBM calculated in the present study were higher than those reported in other studies. Just et al. (1982) determined the nutritive value of 17 different meat and bone meal batches and ob- tained apparent CP digestibilities from 0.72 to 0.82, apparent CF digestibilities from 0.08 to 0.70, and ME contents from 6.1 to 11.0 MJ/kg DM. The live weight of the pigs used in that experi- ment was from 50 to 65 kg, whereas the pigs used in the present study were heavier (88- H3kg). It is generally accepted that the digestibility of dietary nutrients and energy is improved with in- creasing body weight (Roth and Kirchgessner 1984), which partly explains the high digestibili- ties obtained in the present study. The improved apparent digestibility of nutrients is due to the increased contribution of the hindgut to digestion of the diet as live weight increases (Noblet and Shi 1993). In comparative digestibility experiments, sows have been found to digest the nutrients and ener- gy of several feed ingredients, including meat and bone meal, more efficiently than growing 451 Agricultural Science in Finland 3 (1994)Research Note Agricultural Science in Finland 3 (1994) Table 3. Faecal digestibility of nutrients and nitrogen bal- ance of experimental diets. Diet A B SEM Signif. Organic matter 0.863 0.852 0.0021 Crude protein 0.833 0.853 0.0039 Crude fat 0.612 0.646 0.0070 * Ash 0.354 0.299 0.0102 NS N intake, g/d 54.4 73.7 0.35 *** Faecal N, g/d 9.1 10.8 0.30 * Urinary N, g/d 25.8 38.0 0.82 *** Urea N, g/d 21.5 33.1 1.00 ** N retained, g/d 19.5 24.9 0.48 ** -of intake 0.359 0.338 0.0065 NS -of absorbed 0.431 0.397 0.0070 * -per kg W 075 0.617 0.784 0.0203 ** Biological value 0.537 0.476 0.0069 ** *** (p < 0.001), ** (p < 0.01), * (p < 0.05) and NS (non- significant). pigs. Fernändez et al. (1986) obtained CP di- gestibilities of 0.79 and 0.86, CF digestibilities of 0.26 and 0.74, and energy digestibilities of 0.61 and 0.82 in meat and bone meal for growing pigs (40-60 kg) and sows, respectively. Corre- spondingly, Shi and Noblet (1993) reported CP digestibilities of 0.67 and 0.78, and energy di- gestibilities of 0.490 and 0.774 in meat and bone meal for growing pigs (45 kg) and sows. How- ever, the digestibilities obtained for growing pigs in the present experiment were even higher than those obtained for sows in the previous studies. The feeding level may also have affected the digestibilities of nutrients. A reduction in the feed- ing level is usually associated with an increased digestibility, which is related to the longer reten- tion time of food in the digestive tract (Roth and Kirchgessner 1984,Everts et al. 1986, Noblet and Shi 1993). The daily feed intake in the present study was relatively low, averaging 75 g DM/kg W07 5. N retention increased with an increasing level of MBM in the diet (p < 0.01), but at a slower rate than N intake (Table 3). This was found to be related to increased urinary N losses (p < 0.001). N retention was 0.701 g/kg W ,,75/d on an average. The proportion of digested N that was retained (p < 0.01) and the biological value of dietary protein (p < 0.01) decreased with an increasing MBM supply. Although the protein in the MBM diets was highly digestible, its biological value was low due to the high urinary N excretion. This may have been due to several reasons. With processed feeds, such as meat and bone meal, the protein may have been damaged and the amino acids altered structurally. It has been found that some of these compounds are absorbed but not utilized and are therefore excreted in the urine (Batter- ham 1992). The contribution of the bacteria in the hindgut to the digestion of a dietary protein becomes more important with increasing live weight. The undi- gested protein entering the large intestine of the pig is broken down to ammonia, absorbed, con- verted to urea in the liver and excreted in the urine (Noblet and Shi 1993). The growth of mi- croflora in the large intestine is dependent on the available nitrogen and energy supply (Low and Zebrowska 1989). Infusion of starch into the cae- cum of pigs fed on a barley-meat and bone meal diet depressed the faecal apparent digestibility and urinary excretion of N (Zebrowska et al. 1980). The above results indicated that the route of N excretion changed because the energy sup- ply no longer limited the microbial growth. The high faecal digestibility and urinary excretion of N observed in the present study imply that the energy supply limited the microbial growth in the caecum, and therefore, less N was excreted in faeces. The amino acid balance of the experimental diets used in the present experiment may not have met the balance required by the animal. Wang and Fuller (1989) achieved the highest efficiency of N retention with diets having the following balance of amino acids (g/100 g CP): lysine 6.5 (100), threonine 4.7 (72), valine 4.9 (75), methionine + cystine 4.1 (63), isoleucine 3.9 (60), leucine 7.2 (110), phenylalanine + tyro- sine 7.8 (120) and tryptophan 1.2 (18). In the present study, the experimental diets had only 3.9 g lysine/100 g CP, which is 2.6 g less corn- 1452 Research Note pared with the ideal protein composition. In ad- dition, the threonine and methionine + cystine contents were considerably lower than in the pro- posed ideal protein. Animal by-products have a high content of Ca and P, mainly in inorganic form. The digestibility of P in animal by-products is generally high, rang- ing from 0.68 to 0.91. Around 0.80 of the Pfrom meat meal, bone meal and meat and bone meal is digested (Jongbloed and Kemme 1990). In re- cent experiments, Beers et al. (1993) have ob- tained somewhat lower digestibilities, ranging from 0.589 to 0.690. No information on the di- gestibility of Ca in animal by-products was found in the literature, but it could be assumed to be similar to that of other inorganic Ca sources. The utilization of Ca and P depends on the level of Ca and P intake, as well as on the re- quirement of the animal. Generally, the efficien- cy of Ca (Fernandez 1992) and P (Jongbloed 1987) absorption declines with increasing intake. Urinary P excretion increases as P intake increases (ARC 1981, Jongbloed 1987,Fernandez 1992), whereas urinary Ca excretion is generally negli- gible and, if P is not deficient, it remains rela- tively constant at different Ca intakes (Arc 1981, Fernandez 1992). In the present study, the digestibility of dietary P (Table 4) decreased (p < 0.05) with an increas- ing MBM supply, whereas that of Ca and Mg was not affected (p > 0.05). The urinary excre- tion of minerals was not affected by the MBM supply (p > 0.05). The retention of Ca (p < 0.01) and P (p < 0.05) increased with an increasing MBM supply, whereas that of Mg was not affect- ed (p > 0.05). P retention ranged from 6.2 to 8.9 g per kg live weight gain. Jongbloed (1987) calculated that P retention per kg live weight gain over the range of 15 to 110 kg live weight is between 5.5 and 6.0 g/d, which is somewhat low- er than obtained in this study. The pigs used in the present study had been on low-P diets in a previous experiment, which may have caused the high P retention and lack of response in urinary P excretion. Table 4. Mineral balances of the experimental diets. B SEM Signif.Diet A Calcium Intake, g/d 33.1 63.3 0.30 *** Absorbed, g/d 10.5 17.6 0.84 ** -of intake 0.318 0.278 0.0167 NS Excreted in urine, g/d 0.6 0.9 0.16 NS Retained, g/d 10.0 16.7 0.95 ** -ofintake 0.301 0.264 0.0190 NS -of absorbed 0.945 0.949 0.0135 NS Phosphorus Intake, g/d 22.3 36.5 0.17 *** Absorbed, g/d 9.0 11.5 0.50 * -ofintake 0.406 0.316 0.0168 * Excreted in urine, g/d 3.0 2.9 0.14 NS Retained, g/d 6.0 8.7 0.48 * -ofintake 0.270 0.237 0.0159 NS -of absorbed 0.662 0.748 0.0166 * Magnesium Intake, g/d 3.0 3.6 0.02 *** Absorbed, g/d 0.9 1.1 0.05 NS -ofintake 0.314 0.304 0.0166 NS Excreted in urine, g/d 0.3 0.4 0.06 NS Retained, g/d 0.6 0.7 0.09 NS -ofintake 0.203 0.196 0.0294 NS -of absorbed 0.635 0.646 0.0629 NS *** (p < 0.001), ** (p < 0.01), * (p < 0.05) and NS (non- significant). In addition to the effect of high intake, the efficiency of Ca and P absorption and retention may be affected by the live weight of the pig. Generally, the capacity of absorption and reten- tion of both Ca and P are considered to decline with increasing live weight (ARC 1981). How- ever, FernAndez (1992) has obtained contrary results with growing pigs. The optimum Ca;P ra- tio reported for maximum P retention is 1.3:1 (Jongbloed 1987), whereas thatof meat and bone meal is generally about 2:1. Other results indi- cate that processing may also affect Ca and P digestibility in meat and bone meal (Jongbloed and Kemme 1990). 453 Agricultural Science in Finland 3 (1994)Research Note References Alaviuhkola, T. 1989. Lihaluurehujauho sikojen rehuna. Lihayhtymän tiedotuslehti 2; 15-16. - 1992. Uusi lisäaine ehdolla sikojen rehuihin. Sika 22, 2: 60-61. Andersen, P.E. & Just, A. 1983. Tabeller over foderstof- fers sammensastning m.m. kvaeg-svin. 102 p. Det kgl. danske Landhusholdningsselskab, Kpbenhavn. AOAC 1984. Official methods of analysis. 1141 p. Asso- ciation of Official Analytical Chemist, Inc., Arlington, Virginia. ARC 1981. The nutrient requirements ofpigs. Agricultur- al Research Council, Commonwealth Agricultural Bu- reaux, Slough, UK. 304 p. Batterham, E.S. 1992.Availability and utilization of ami- no acids for growing pigs. Nutrition Research Reviews 5: 1-18. •, Darnell, R.E., Herbert, L.S. & Major, E.J. 1986. Effect of pressure and temperature on the availability of lysine in meat and bone meal as determined by slope-ratio assays with growing pigs, rats and chicks and by chemical techniques. British Journal of Nutri- tion 55: 441-453. Beers, S., Kemme, P.A., Jongbloed, A.W. & Horsting, V.B.J. 1993. P-digestibility in feed phosphates and prod- ucts of animal origin: results of several trials. Part 1: Apparent digestibility of phosphorus in products of animal origin. 25 p. Rapport - Instituut voor Veevoed- ingsonderzoek No. 249. Bruyer, D.C., Foulon, M. & Vanbelle, M. 1990. The amino acid composition of meat and bone meals and its predictability. Archives of Animal Nutrition. Berlin 40: 259-265. Everts, H., Smits, B. & Jongbloed, A.W. 1986. Effect of crude fibre, feeding level and body weight on apparent digestibility of compound feeds by swine. Netherlands Journal of Agricultural Science 34: 501-503. Fernandez, J.A. 1992. Calcium and phosphorus metabo- lism in growing pigs studied by the balance technique and simultaneous radio-calcium and radio-phosphorus kinetics. Ph.D Thesis, The Royal Veterinary and Agri- cultural University, Frederiksberg, Denmark, 148p. -, Jorgensen, H. & Just, A. 1986. Comparative digesti- bility experiments with growing pigs and adult sows. Animal Production 43: 127-132. Fuller, M.F., Livingstone, R.M., Baird, B.A. & Atkin- son, T. 1979. The optimal amino acid supplementation of barley for the growing pig. 1. Response of nitrogen metabolism to progressive supplementation. British Journal of Nutrition 41: 321-331. Graham, H., Fadel, J.G., Newman, C.W. & Newman, R.K. 1989. Effect of pelleting and (J-glucanase supple- mentation on the ileal and fecal digestibility of a bar- ley-based diet in the pig. Journal of Animal Science 67: 1293-1298. ■, Hesselman, K., Jonsson, E. & Åman, P. 1986. Influ- ence of (3-glucanase supplementation on digestion of a barley-based diet in the pig gastrointestinal tract. Nu- trition Reports International 34: 1089-1096. Haugen, E.W., Pettigrew, J.E., Cornelius, S.G. & Mo- ser, R L. 1985. Effects of meat meal manufacturing variations on amino acid bioavailability in pigs. Jour- nal of Animal Science 61 (Supplement I): 100. Jongbloed,A.W. 1987. Phosphorus in the feeding of pigs; effect of diet on the absorption and retention of phos- phorus by growing pigs. 343 p. Doctoral Thesis, Wage- ningen Agricultural University. - & Kemme, P.A. 1990. Apparent digestible phosphorus in the feeding of pigs in relation to availability, re- quirement and environment. I. Digestible phosphorus in feedstuffs from plant and animal origin. Nether- lands Journal ofAgricultural Science 38: 567-575. Just, A., Fernandez, J.A. & Jorgensen, H. 1982. Kod- benmels vaerdi til svin. 52 p. 525. Beretning fra Sta- tens Husdyrbrugs forspg. Knabe, D.A., Laßue, D.C., Gregg, E.J., Martinez, G.M. & Tanksley, T.D., Jr. 1989. Apparent digestibility of nitrogen and amino acids in protein feedstuffs by grow- ing pigs. Journal of Animal Science 67: 441-458. Low, A.G. & Zebrowska, T. 1989. Digestion in pigs. In: Bock, H.D. et al. (eds.). Protein metabolism in farm animals. Oxford university Press, Berlin, p. 53-121. Miller, E.L. & De Boer, F. 1988. By-products of animal origin. Livestock Production Science 19: 159-196. Noblet, J. & Shi, X.S. 1993. Comparative digestibility of energy and nutrients in growing pigs fed ad libitum and adult sows fed at maintenance. Livestock Produc- tion Science 34: 137-152. Roth, F.X. & Kirchgessner, M. 1984. Verdaulichkeit der Energie und Rohnährstoffe beim Schwein in Abhän- gigkeit von Futterungsniveu und Lebendgewicht. Zeitschrift fur Tierphysiologie, Tierernährung und Fut- termittelkunde 51: 79-87. Salo, M.-L., Tuori, M. & Kiiskinen, T. 1990. Rehutaulu- kot jaruokintanormit. 70 p. Yliopistopaino, Helsinki. Schneider, B.H. & Flatt, P.W. 1975. The evaluation of feeds through digestibility evaluation. 423 p. Univer- sity of Georgia Press, Athens, Georgia. Shi, X.S. & Noblet, J. 1993. Digestible and metaboliza- ble energy values of ten feed ingredients in growing pigs fed ad libitum and sows fed at maintenance level; comparative contribution of the hindgut. Animal Feed Science and Technology 42: 223-236. Skilton, G.A., Smith, W.C. & Moughan, P.J. 1991. The ileal digestibility of nitrogen and amino acids in meat and bone meals determined using a rat assay. Animal Feed Science and Technology 34: 111-126. Snedecor, G.W. & Cochran, W.G. 1989.Statistical meth- ods. 503 p. Bth ed. lowa University Press, Ames, lowa. Tayssky, H.H. & Shorr, E. 1953. A microcolorimetric method for the determination of inorganic phosphorus. Journal of Biological Chemistry 202: 675-685. Wang, T.C, & Fuller, M.F. 1989. The optimum dietary 454 Research NoteAgricultural Science in Finland 3 (1994) Research Note amino acid pattern for growing pigs. 1, Experiments by amino acid deletion. British Journal of Nutrition 62; 77-89. Zebrowska, T., Zebrowska, H. & Buraczewska, L. 1980. The relationship between amount and type of carbohy- drates entering the large intestine and nitrogen excre- tion in faeces and urine of pigs. In: Proceedings of the 3rd EAAP symposium on protein metabolism and nu- trition. EAAP Publication No. 27. p. 222-226. Manuscript received January 1994 SELOSTUS Lihaluurehujauhon ravitsemuksellinen arvo lihasikojen ruokinnassa Kirsi Partanen ja Matti Näsi Helsingin yliopisto Tutkimuksessa selvitettiin lihaluujauhon rehuarvoa lihasi- kojen ruokinnassa. Tutkittavassa lihaluujauhossa oli 322 g tuhkaa ja 478 g raakavalkuaista per kg kuiva-ainetta. Li- haluujauhon ravintoaineiden sulavuutta sekä valkuaisen ja kivennäisaineiden hyväksikäyttöä tutkittiin sulavuus- ja tasekokeessa. Kokessa oli 6 lihasikaa, joiden elopaino oli 88-113 kg. Sioille syötettiin ohrapohjaisia rehuseok- sia, joihin oli lisätty joko 100 tai 200 g lihaluujauhoa per kg. Koeruokintojen orgaanisen aineen sulavuus aleni hiu- kan ja raakarasvan sulavuus parani, kun lihaluujauhon osuus rehuseoksessa kasvoi. Raakavalkuaisen sulavuus parani myös lihaluujauhon saannin kasvaessa, mutta sa- malla virtsassa eritetyn typen määrä kasvoi ja valkuaisen hyväksikäyttö heikkeni. Lihaluujauhon ravintoaineiden reg- ressiona lasketut sulavuuskertoimet olivat korkeita; or- gaanisen aineen sulavuus oli 0,910, raakavalkuaisen 0,909 ja raakarasvan 0,730. Lihaluujauhon energia-arvoksi saa- tiin 0,98 ry/kg ka. Lihaluujauhossa on runsaasti kiven- näisaineita, erityisesti kalsiumia ja fosforia. Rehussa yli- määrin saatu kalsium ja fosfori erittyy sonnan ja virtsan mukana. 455 Agricultural Science in Finland 3 (1994)