Maataloustieteellinen Aikakauskirja Vol. 57: 263—269, 1985 Rapeseed meal of low- and high-glucosinolate type fed to growing-finishing pigs MATTI NÄSI, TIMO ALAVIUHKOLA and KAIJA SUOMI University of Helsinki, Department of Animal Husbandry, SF-00710 HELSINKI Agricultural Research Centre, Swine Research Station, SF-05840 HYVINKÄÄ Abstract. The nutritive value of five lots of rapeseed meal (RSM) from Brassica campestris or B. napus with different levels of glucosinolates (GL) was investigated in a digestibility and balance trial with a 5 x 5 Latin square design and in agrowth trial with 140growing-finishing pigs. The RSM’s were prepared from the cultivars: Span-Torch, Sigga, Gulliver and Topas, and a heat-treated RSM was also studied, their total GL contents (gmol/g defatted meal) being 42, 11, 98, 27 and 8, respectively. Cv. Sigga had yellow hulls and a lower ADF content than the other cultivars. The hat-treated RSM had a reduced lysine content. There were no significant (P > 0.05) differences in organic matter or crude protein digestibilities between the RSM’s with different GL levels or the RSM’s prepared from B. cam- peslris and B. mpus, when RSM was used as the only protein supplement at a level of 20—25 % in a barley-based diet. Heat treatment reduced the organic matter and crude protein digest- ibilities (P < 0.01). Nitrogen retention and protein utilization were lower (P < 0.01) on the diet supplemented with heat-treated RSM than on the diets with the other RSM’s but other- wise there were no significant differences between them (P > 0.05). In the growth trial supplementation with HGL-RSM Gulliver (14 % in diet) caused some palatability problems and this led to reduced performance (P < 0.05), but there were no dif- ferences between the other groups receiving 14—15 % RSM and the SBM control group (P > 0.05). The carcass quality was similar in all the groups. The weight of the thyroid gland was higher in the pigs receiving RSM than in the SBM controls, by 6—57 % (P < 0.05). In the present study a fairly high RSM supplements from cultivars with a moderate high GL content could be used in the diet of growing pigs without impairing their performance, when the diet was formulated on the basis of the digestible nutrients of RSM. Heat-treated RSM, with protein of low rumen degradability, is of poor value in pig feeding due to the low digestibility and availability of its protein. Index words: Rapeseed meal, glucosinolates, protein supplement, pig feeding, digestibility. 263 JOURNAL OF AGRICULTURAL SCIENCE IN FINLAND https://www.c-info.fi/en/info/?token=iGwBgxeqdW4Vc9_j.2_8bWaW04oPmi-glSvkcpw.V0n1C7kIomF42g0QL7fxkJuCYD0PoID-DXXASLAlhbh1-GOynAuvSZXPYs4-Sez2ES13ub-l1Bz7PCUmBDoFlSAKeh3HPPUOhutpOjnZ-_xbvm0D6PxgR97X2g7llsXwJ6RrGqZxEXjwV1lIBEIo0bTHcxmoQf_Kbthl6WiyRDetKPf1yhkIIWvsYAZkV897M6ZvnneOR_l87I5MgOB3 Introduction In Finland, production of rapeseed is one of the most readily available means of increas- ing the domestic supply of protein of high biological value for animal feeding. Rapeseed, both Brassica campestris and B. napus, is the only oil seed suitable for commercial cultiva- tion in the climatic conditions of this country and its production has increased rapidly over the past decade. Rapeseed meal (RSM) con- tains 35—40 ®/o crude protein and RSM pro- teins have a well-balanced amino acid pattern, but their availability is rather low (Sauer et al. 1982). The antinutritional and toxic con- stituents of rapeseed are known greatly to re- strict the utilization of RSM as a feed for monogastrics (Bell 1984). The fibre content of RSM is almost double that of soybean meal (SBM), which lowers the digestibility and feed value (Salo 1982). The most important factor limiting the potential RSM as a protein supplement in pig feeding is the presence of glucosinolates (Rundgren 1983). Some of these are goitro- genic and others are potentially hepatotoxic, whilst the majority are volatile and have a strong bitter taste (Bell 1984). Meals pre- pared from rapeseed varieties with low or medium contents of glucosinolates are finding increased acceptance as a protein source in pig diets and are being used as a replacement for SBM (Alaviuhkola 1981, Salo 1982, Thomke et al. 1983, Thomke 1984). The breeding work directed towards reduction of the hull content may also make RSM more suitable for pig feed. Some studies have shown that RSM maytotally or partially replace SBM in growing-finishing pig diets without adverse effects of performance, while other studies have shown that complete or partial substitu- tion of RSM for SBM affects pig performance adversely (Rundgren 1983). The present study was conducted to com- pare the nutrient digestibility of rapeseed meals with different levels of glucosinolates and their effects on the performance of growing-finishing pigs. One of the RSM’s was heat-treated in order to obtain information on the nutritive value on the RSM with low rumen degradable protein in pig feeding. Materials and methods Experimental feeds Two of the feeds from Brassica campestris were of Finnish origin: a commercial high- glucosinolate rapeseed meal (HGRSM) pre- pared from cv. Span-Torch and a low-gluco- sinolate rapeseed meal (LGRSM) prepared from cv. Sigga. Two lots of B. napus meal were obtained from Sweden: HGRSM cv. Gulliver and LGRSM cv. Topas. One lot of B. napus meal was processed in Denmark to reduce the rumen degradability of the protein. The seeds were flaked, cooked, expelled through a press, extracted with hexane, de- solvetized and toasted. The composition of the glucosinolates was as follows: B. campestris B. napus Span Sigga Gulliver Topas Heat treat. Gluconapin 13.8 3.8 25.9 7.0 3.2 Glucobrassicanapin 11.2 2.2 5.8 2.2 2.1 Progoitrin 15.0 4.6 64.0 17.4 3.1 Napoleiferin 2.2 0.5 2.2 0.5 0 Concentrations expressed as /tmol/g defatted meal Analysis made al University of Technology, Department of Chemistry by courstesy of Dr. Anneli Hase. Digestibility and balance trial The experiment involved five isonitrogen- ous, 16 °7o crude protein diets, in which RSM’s of HG or LG types were used as pro- tein supplements. The diets were enriched with 40 g/d mineral mixture and 15 g/d vitamin mixture and had the following composition; Diet Barley RSM Starch 1. HGRSM Span-Torch 75.0 25.0 0.0 2. LGRSM Sigga 75.0 25.0 0.075.0 25.0 0.0 3. HGSRM Gulliver 75.0 21.9 3.1 4. LGRSM Topas 75.0 20.2 4.875.0 20.2 4.8 5. LGRSM Heat-treat. 75.021.5 3.5 264 Five crossbred barrows, weighing 29 kg ini- tially and 71 kg finally, were rotated through five successive feeding periods in a 5 X 5 Latin square arrangement. One pig was fed on only barley plus minerals, to obtain the basal diet digestibilities. Each period com- prised 6 days of adjustment and 6 days of faecal and urine collection, as described by Nasi (1984). The coefficients of the apparent digestibility of the nutrients and the nitrogen balance were calculated for each diet and, using the difference method, for each RSM, too. The digestibility coefficients were anal- ysed statistically as a Latin square design. Growth trial A hundred and forty cross-bred Landrace and Large White pigs averaging 25 kg live weight were allotted to five experimental groups on the basis of litter origin, sex and initial live weight. Each group consisted of 14 replicates of two pair-fed pigs. The diets were formulated to contain 135 g DCP/FU and minerals and vitamins according to the re- quirements (Salo et al. 1982). The five for- mulas, in which the rapeseed meals replaced soybean meal had the following dietary com- position: B. campestris B. napus Ingredients 0- 00- 0- 00- Control rape rape rape rape SBM 77.5 77.5 78.5 78.5 82.5Barley HGRSM Span- Torch 15.0 LGRSM Sigga 15.0 HGRSM Gulliver LGRSM Topas Soybean meal 14.0 14.0 * 1.0 1.0 1.0 1.0 11.0 3.0 3.0 3.0 3.0 3.0 3.5 3.5 3.5 3.5 3.5 Fish meal Min. vit. mix. FU/kg feed DCP/FU,g 0.926 0.933 0.930 0.931 0.964 137 134 138 140 136 The pigs were fed according to a weight- based restricted feeding scale (Salo et ai. 1982). Individual live weights and feed con- sumption on a pen basis were recorded at weekly intervals. The pigs were sent to slaugh- ter when they reached 95 kg live weight. The carcass evaluation was made by measuring the ratio of lean to fat, the colour of the lean and pH. The thyroid weights were also determined on the recovered portion of 50—67 % of the pigs in the different groups. Results and discussion The total glucosinolate levels (/rmol/g de- fatted meal) of the rapeseed meals investigated in this study were: B. campestris Span- Torch 42.2 (HGRSM) and Sigga (LGRSM) 11.1 and for B. napus Gulliver 97.9 (HGRSM), Topas 27.1 (LGRSM) and heat treated RSM 8.4. The Finnish commercial RSM originates mainly from B. campestris cultivars Span, Torch and Emma, which have much lower total glucosinolate contents less than B. napus HG types. The content of nitrils was 1.7 gmol/g in meal from Sigga and 2.1—2.6 in the other RSM’s. In the RSM’s originating from B. cam- pestris the crude protein content was 7 % units lower and the fat left in solvetizing was 10 °7o, the process thus differing between the various RSM’s (Table 1). Crude fibre was at the same level in all the RSM’s except cv. Topas, in which it was a little lower. Cv. Sigga is a yellow thin-coated type, but had no dif- ference in crude fibre (Table 1). However, the analysis for acid detergent fibre and acid detergent lignin showed that Sigga had one quarter less ADF and only half the ADL value than the others. The hulls from yellow cul- tivars contain less crude fibre than those from the dark cultivars (Stringham et al. 1974, Bell and Shires 1982). The yellow hulls have a higher amount of polysaccharides and less polyphenols than the dark hulls (Theander et al. 1977). The amino acid composition was fairly sim- ilar in the different RSM’s (Table 1). Heat- treated RSM had a reduced lysine content, the available lysine being especially low, 2.6 g/16 g N vs. 4.1—4.2 in the other RSM’s. The rumen degradability of the heat-treated RSM 265 266 Table 1. Chemical composition of rapeseed meals from different cultivars. B. campestris B. napus HGRSM LGRSM HGRSM LGRSM LGRSM Span-Torch Sigga Gulliver Topas Heat treated Dry matter % 88.4 89.6 89.3 89.0 86.3 Ash, % 7.3 7.3 7.4 7.4 7.5 Crude protein, % 35.2 34.0 39.6 43.1 41.9 True protein, % 30.9 31.3 33.2 39.5 38.6 Ether extract, % 7.9 12.3 1.9 3.0 4.6 Crude fibre, % 15.7 16.7 16.1 12.6 15.1 Nitrogen free extract, % 33.9 29.8 35.0 34.0 30.9 Acid detergent fibre, % 21.4 15.1 20.9 18.9 21.7 Neutral detergent fibre, % 24.7 30.0 26.0 24.8 30.5 Acid detergent lignin, % 10.0 4.6 9.4 9.1 11.0 Total glucosinolates/jmol/g 42.2 11. 1 97.9 27.1 8.4 Progoitrin, ftmol/1 15.0 4.6 64.0 17.4 3.1 Tannin, % 1.4 1.7 1.6 1.8 1.5 Amino acids, g/16 g N Alanine 4.3 4.1 4.2 4.2 4.1 Arginine 6.6 6.3 6.9 7.2 6.3 Aspartic acid 6.5 7.8 6.5 6.9 7.9 Cystine 1.3 1.5 1.7 1.4 1.2 Glutamic acid 20.3 20.2 20.0 20.6 18.3 Glycine 5.7 5.4 5.6 5.7 5.4 Histidine 2.6 2.9 2.9 3.3 2.8 Isoleucine 4.2 3.9 3.9 4.2 4.3 Leucine 7.1 6.2 6.4 6.5 7.1 Lysine 6.3 5.5 6.5 6.0 4.6 Methionine 1.1 1,2 1.1 1.2 1.3 Phenylalanine 3,8 3.5 3.5 3.3 3.7 Proline 6.7 5.9 7.0 6.6 6.0 Serine 4.7 4.4 4.5 4.4 4.3 Threonine 4.7 4.5 4.7 4.6 4.5 Tyrosine 2.8 3.0 2.7 2.8 3.0 Valine 5.1 5.0 4.9 5.1 5.1 Available lysine 4.2 4.1 4.4 4.4 2.6 protein was 30 %, as opposed to 50—60 % in the other RSM when measured in sacco for 18 h in the rumen (Näsi 1984). The heat treatment was evidently rather strong, since the degradability of the other RSM protein was already low after the normal meal processing. The content of sulphur amino acids in the RSM’s was rather low in the present study, compared for example, with the results of Bell (1984). The digestibility coefficients of the nutrients of the different RSM’s calculated by the dif- ference method are shown in Table 2. There was no significant (P > 0.05) difference in the organic matter (61 —70 %) or crude protein digestibilities (70 —74 %) between HGRSM’s and LGRSM’s or between B. campestris and B. napus, but the B. napus meal had lower organic matter digestibility due to its lower fat content, whilefat was digested fairly efficient- ly. According to the literature, HGRSM organic matter has a digestibility of 67—69 and that of LGRSM 70—84 %, and the di- gestibility of their crude protein is 67—80 and 72—86, respectively (Rundgren 1983). The heat treatment reduced the digestibility of organic matter and crude protein significant- ly (P < 0.05). The heat treatment was evi- dently rather hard, which decreased the digest- ibility and availability. The RSM’s from B. campestris had higher feed values because of their higher fat content, 0.96—0.87FU/kg DM vs. 0.74—0.70 of RSM from B. napus. Table 2. Digestibility coefficients of nutrients from different rapeseed meals and their calculated feed values. B. campeslris B. napus HGRSM LGRSM HGRSM LGRSM LGRSM Span-Torch Sigga Gulliver Topas Heat treated X s.d. X s.d. X s.d. X s.d. X s.d. Digestibilities Dry matter 65.0“b 9.3 65.5“ 4.2 57.1“ b 6.4 60.9“ b 3.8 54.0» 8.4 Ash 35.4“ 17.3 23.9“ 5.1 25.7“ 11.6 36.3“ 6.9 26.8“ 7.1 Organic matter 68.4«b 8.6 69.8“ 3.9 60.7“ b 5.2 63.9“ b 3.8 57.7» 7.1 Crude protein 73.7“ 5.4 70.9“ 3.1 70.1“ 5.3 73.4“ 4.5 68.7“ 6.9 Ether extract 56.7“ b 17.6 75.1“ 9.6 neg 5.4» 42.4 49.6“» 16.9 Crude fibre 51.7“ bd' 17.3 66.2“d 13.2 40.5“ bd' 15.7 34.8 bd' 10.4 25.0»' 15.5 Nitrogen free extract 72.7“ 10.8 67.7“ 8.8 66.8“ 9.1 67.2“ 9.4 59.3“ 5.8 Feed values FU/kg DM 0.870 0.958 0.724 0.741 0.698 kg/FU 1.30 1.17 1.55 1.52 1.66 DCP % in DM 25.9 24.1 27.8 31.6 28.0 g DCP/FU 298 252 384 427 413 MJ, ME/kg DM (Just) 12.87 14.01 11.06 11.48 10.80 MJ, NE/kg DM » 7.77 8.63 6.42 6.73 6.22 FU, NE/kg DM » 1.01 1.12 0.83 0.87 0.81 MJ, ME/kg DM (Axelsson) 11.97 12.92 10.32 10.70 10.03 Means with different letters were significantly different (a —c P<0.05, d—f PcO.Ol) Table 3. Nitrogen balance and biological value of diets including rapeseed meals from different cultivars and daily gain of pigs. B. campeslris B. napus HGRSM LGRSM HGRSM LGRSM LGRSM Span-Torch Sigga Gulliver Topas Heat treated X s.d, X s.d. X s.d. X s.d. X s.d. N intake, g/d 42.4» 11.141.9“ 10.942.3“ 11.041.8“ 10.842.5“ 11.0 N excreted in faeces, g/d 10.9“b 2.611.4“b 2.511.6“b 2.510.7b 2.111.9“ 2.1 N absorbed, g/d 31.5“ 8.730.6“ 8.530.7“ 8.731.1“ 8.830.7“ 9.1 N excreted in urine, g/d 11.6b 3.411.8 b 3.811.6b 4.012.2“b 4.413.7“ 4.9 N retained, g/d 20.0d 5.418.8 d 4.719.1d 4.818.8d 4.6 16.9' 4.3 % of intake 46.9 d 1.245.0d 0.845.2d 2.745.2d 2.1 39.8' 1.9 % of absorption 63.4 d 2.061.9d 2.162.6d 3.061.l d 3.2 55.8' 2.9 N retained, g/kg W» 7 Vd 1.10“d 0.061.01 bd' 0.081.05“bd 0.101.03bd' 0.090.93“ 0.07 Urea excreted, g/d 19.7b ' 6.419.7 b' 6.818.4b' 7.320.1bd' 8.224.9“d 8.9 Urea excreted, g/kg WO7Vd I.oB' 0.18 1.07' 0.130.99f 0.21 I.oB' 0.241.34d 0.23 Creatinine excreted, g/d 1.71“ 0.511.73“ 0.711.67“ 0.561.66“ 0.531.59“ 0.48 Biological value 71.2“ 2.270.l d 2.370.7d 3.1 69.3d 3.3 64.5' 3.4 Daily gain, g/d 687“ 84 656“ 149 693“ 147 604“ 151 645“ 213 Means with different letters were statistically significant (a —c P<0.05; d-f PcO.Ol) Table 3. presents data on the nitrogen bal- ance and protein utilization. The differences between HG and LG rape types were small and also those between the two Brassica spe- cies (P > 0.05). Heat treatment reduced ni- trogen retention and protein utilization (P < 0.01). N retention calculated as g/kg W075 was lower in RSM from Sigga and Topas than 267 Table 4. Growth rate, feed utilization and carcass quality of pigs on diets in which soybean meal was replaced with different types of rapeseed meal. Diets B. campestris B. napus HGRSM LGRSM HGRSM LGRSM Control Span Sigga Gulliver Topas SBM Initial weight, kg 25.0 25.0 25.0 24.8 25.0 Final weight, kg (corr.) 96.0 96.8 96.6 96.4 97.2 Loss at slaughter, % 28.4 28.3 29.2 28.5 27.4 Daily weight gain, g 771 ab 796b 747 a 777 ab 787 b FU/pig/d 2.13 2.19 2.12 2.17 2.16 FU/kg gain 2.78 2.75 2.85 2.81 2.75 Kg DM/kg gain 2.57ab 2.54ab 2.65a 2.59ab 2.44b Side fat, mm 16.8 16.8 16.7 17.0 17.9 Eye, muscle area, cm2 38.0 38.7 37.5 37.3 39.3 Colour of lean (points I—s) 2.4 2.4 2.5 2.5 2.3 Meat in valuable cuts, % 80.6 80.8 80.7 80.6 80.9 Thyroid gland, g 8.8ab 8.4ab 12.4a 9.4 ab 7.9 b Thyroid gland, rel. (Ill) (106) (157) (119) (100) Means with different letters were significantly different (a —b P<0.05) in RSM from Span-Torch (P < 0.05), and heat-treated RSM had a lower value than all the other RSM’s (P < 0.05, 0.01). The urea excretion, which gives an indication of the amino acid balance in the diet, accorded with the nitrogen retention results; heat treatment of RSM increased urea excretion (P < 0.01). The biological values of the various RSM diets were quite close to each other (69 —71), but in the diet supplemented with heat-treated RSM this value was significantly reduced (P < 0.01). The daily gains recorded after each 12-daybalance trial were 600—690 g and differences between the treatments were small (P > 0.05). In the growth trial palatability problems oc- curred in the groups receiving RSM derived from Gulliver and slight problems in the groups given Span-Torch meal, so that the daily allowances had to be temporarily re- duced. This was partly reason for the lower performance of the HGRSM Gulliver group (P < 0.05). There were no differences in daily gain between the other RSM groups and the control group receiving SBM. The group re- ceiving LGRSM Sigga performed fairly well; the daily gain was 796 g, as against the con- trol value of 787 g, and the feed conversion efficiency was the same for the two groups, 2.75 FU/kg gain. The carcass quality was similar in all the groups (P > 0.05). The weight of the thyroid gland was elevated in pigs receiving RSM com- pared to the control value. HGRSM Gulliver gave an increase of 57 %, while in the others it was 6 to 19 % (P < 0.05). These results are in accordance with the progoitrin content of the RSM’s. Acknowledgements. The authors are indebted to Ms. Eija Lämsä, M.Sc. & Agr., for technical assistance and to Öljynpuristamo Oy for financial support. References Alaviuhkola, T. 1982. Rypsirouheen käyttömahdolli- suudet sikataloudessa. Sika No 2: 10—11. Bell-, J.M. 1984. Nutrients and toxicants in rapeseed meal: a review. J. Anim. Sci. 58: 996—1010. & Shires, A. 1982. Composition and digestibility by pigs of hull fractions from rapeseed cultivars with yellow or brown seed coats. Can. J. Anim. Sci. 62: 557—565. Näsi, M, 1984 a. Nutritive value and metabolic effects 268 of whey proteinconcentrate and hydrolysed lactose for growing pigs. J. Agric. Sci. Finl. 56: 227—238. 1984 b. Eri rypsi- ja rapsilajikkeiden hyväksikäyttö lihasialla. Suomen Maataloustieteellisen Seuran Tiedote No 4: 52—58. Rundoren, M. 1983. Low-glucosinolate rapeseed pro- ducts for growing pigs a review. Anim. Feed Sci. Technol. 9: 239—263. Salo, M-L. 1982. Rapeseed meal as a protein source for growing pigs. J. Scient. Agric. Soc. Finl. 54: 313—320. —, Tuori, M. & Kiiskinen, T. 1982. Rehutaulukot ja ruokintanormit. 70 p. Helsinki. Sauer, W.C., Cichon, R, & Misir, R, 1982. Amino acid availability and protein quality of canola meal and rapeseed meal for pigs and rats. J. Anim. Sci. 54: 292—301. Stringham, G.R., McGregor, D.l. & Pawlowski, S.H. 1974. Chemical and morphological characteristics as- sociated with seed coat color in rapeseed. Proc 4 th Int Rapeseed Conf. Giessen, pp. 99—108. Theander, 0., Ahman, P., Mische, G.E. & Yasuda, S. 1977. Carbohydrates, polyphenols and lignin in seed hulls of different colors from turnip rapeseed. J. Agric. Food Chem. 25: 270—273. Thomke, S. 1984. Further experiments with RSM of Swedish low-glucosinolate type fed to growing-finishing pigs. Swedish J. Agric. Sci. 14: 151—157. —, Elwinoer, K., Rundoren, M. & Ahlström, B. 1983. Rapeseed meal of Swedish low-glucosinolate type fed to broiler chickens, laying hens and growing-finishing pigs. Acta Agric. Scand. 33: 75—96. Ms received September 30, 1985 SELOSTUS Runsaasti ja vähän glukosinolaatteja sisältävät rypsi- ja rapsirouheet lihasikojen valkuaisenlähteenä Matti Näsi, Timo Alaviuhkola ja Kaija Suomi Helsingin yliopisto, kolieläinlieleen laitos, 00710 Helsinki Maatalouden tutkimuskeskus, sikatalouden tutkimusasema, 05840 Hyvinkää Sulavuus- ja tasekokeessa sekä kasvatuskokeessa tut- kittiin kahden rypsirouheen Brassica campeslris ja kol- men rapsirouheen B. napus arvoa lihasikojen valkuais- lähteenä. Rouheista oli kaksi runsaasti glukosinolaatte- ja sisältäviä, lajikkeet Span-Torch (0-rypsi) ja Gulliver (0-rapsi) ja kaksi vähän glukosinolaattejasisältäviä Sig- ga (00-rypsi) ja Topas (00-rapsi) sekä yksi lämpökäsitel- ty rapsirouhe. 00-rypsi Sigga oli keltasiemeninen ohut- kuorinen tyyppi, jonka happodetergentti kuidun pitoisuus oli 3/4 osaa muiden rouheiden arvosta. Sulavuus- ja ta- sekokeessa (5x5 latinalainen neliö) rypsi/rapsirouhe oli yksinomaisena valkuaislisänä, 20,2 —25.0 % dieetistä. 0-rypsin ja 00-rypsin tai -rapsienvälillä ei ollut merkitse- viä eroja eri ravintoaineiden sulavuuksien välillä raaka- kuitua ja -rasvaa lukuunottamatta. Eri rouheiden koos- tumus oli kuitenkin erilainen mm. rypsirouheissa oli ras- vaa n. 10 % kun rapsirouheisiin oli jätetty vain 3 %. Läm- pökäsitelty rapsirouhe oli sulavuudeltaan merkitsevästi muita rouheita huonompaa. Rypsirouheiden ry-arvo oli 0.87—0.96 ja rapsirouheiden00.70.74kg/ry eron joh- tuessa pääasiassa erilaisesta rasvapitoisuudesta. Kasvatuskokeessa rypsi/rapsirouheen osuus dieetissä oli 14—15 % ja vertailuseoksessa oli soijarouhetta. Kai- kissa koeryhmissä oli 28 eläintä, jotka ruokittiin yhdellä seoksella (135 g srv/ry) koko kasvatuskauden, 25—95. 00-rapsia saaneilla eläimillä esiintyi jonkin verran syömät- tömyyttä. Lisäkasvu oli merkitsevästi tällä ryhmällä alem- pi kuin muilla. Rehun hyväksikäytössä (ry/kg lisäkasvua) ei ollut ryhmien välillä tilastollisesti merkitseviä eroja, ei myöskään teuraslaadussa. Kilpirauhasen paino oli kaikilla rypsi/rapsirouhetta saaneilla eläimillä suurempi kuin soi- jaryhmän eläimillä. 269