JOURNAL OF THE SCIENTIFIC AGRICULTURAL SOCIETY OF FINLAND Maataloustieteellinen Aikakauskirja 305 Voi. S4: 303-312, 1982 Nutritive value of rapeseed meals and cakes for pigs and sheep MAIJA-LIISA SALO Department of Animal Husbandry, University of Helsinki, 00710 Helsinki 71, Finland Abstract. Digestibility and nutritive value for growing pigs, liveweight 40-70 kg, were determined for high glucosinolate (HG) Span and Torch (Brassica campestris) rapeseed meals (RSM) and cakes (RSC), and for low glucosinolate (LG) Regent (B. napus) RSM and DF-15 (B. campestris) RSC in barley based diets in one year or two successive years. Some of the feeds were evaluated also for sheep. The level of RSM and RSC was 20 or 30 % of diets for pigs and 32 % for sheep. The observed net energy value of commercial Span-Torch RSM for pigs was in two successive years 0.80 and 0,79 f.u./kg dry matter (DM) ( f.u. = feed unit = 0.7 kg starch equivalent). The protein values were 281 and 291 g digestible crude protein (DCP)/kg DM, respectively. The 8 %-units higher fat content together with a little better digestibility of organic components raised the f.u. value of RSC about 30 % above that of RSM. For pigs there were only slight differences in the digestibility and palatability of the HG Span-Torch and the LG Regent and DF-15 meals and cakes, but there was a clear difference in the palatability in successive years. The nitrogen balances for pigs on the RSM or RSC and barley diets were 20.4-22.2 g N/d, and the biological values of protein of the RSM and RSC were 67-68. The net energy value of Span-Torch rapeseed meal for sheep was 0.91 f.u./kg DM, and the protein value 309 g DCP/kg DM. The digestibility of cakes was nearly equal to meal, but the 8 %-units higher fat content raised the f.u. value of RSC about 20 %. The digestibility of organic matter of LG DF-15 cakes was a little better (P < 0.05) than that of Span-Torch cakes. The sheep willingly ate RSM and RSC at a 32 % level of the diets. Introduction Numerous experiments have indicated that the energy value of rapeseed meal (RSM) is lower than soybean meal for pigs (e.g. McKINNON and BOWLAND 1977, KENNELLY et al. 1978, AHERNE and LEWIS 1978, ALAVIUHKOLA 1979); conflicting results have been found for ruminants (WOOD and STONE 1979, STAKE et al. 1973, SHARMA et al. 1980). The digestibility of RSM protein is poorer for both animal species. The nutritive value of RSM varies with the cultivar, the glucosinolate content, environmen- tal conditions and processing methods (BELL et al. 1976). Most recent studies have been concerned with low glucosinolate (LG) RSM. In Finland, however, climate imposes a preference for the high glucosinolate (HG) Brassica campestris cultivars (cv. Span and Torch). https://www.c-info.fi/en/info/?token=upLlL62THEgMW17i.SfF5GpwQqAiBMdi3Oxu40w.41P2gaEgbJ2W8ajA-HgSPxIDncXApRRm-QwZTqPiZMw3Xcptj81_vv4cPhQoXooHylqQr0yrzyvNaE3HnwEzZ07REW4yzPv0nYpao-dtLSb5JnZLDncj4Utl-31zEt0FHFOLzoWSIz-WFf1L4UtPLVmx6WcIXcAnc6YKapU7 306 The objective of the present study was to evaluate domestic pre-pressed, solvent-extracted rapeseed meals for growing pigs and sheep and compare them with rapeseed cakes (RSC), as well as with meals and cakes prepared from some newer rapeseed varieties. Materials and methods Feeds The chemical compositions of the investigated RSM and RSC are pre- sented in Table 1. Span and Torch varieties are widely cultivated in southern Finland. Since the meals are not marketed separately and are much alike in chemical composition, they are expressed here as ’’Span-Torch”. Samples represented commercial RSM, originating from different processing plants in different years. The Span-Torch cakes were of the same origin as meals, differing only in being pressed. DF-15 (B. campestris ) and Regent (B. napus) are LG varieties, grown at research stations. The former was only pressed, the latter also slightly extracted. According to information supplied by the processor the glucosinolate content of the seeds of Span and Torch is about 3 %, that of DF-15 about 1.5 % and of Regent < 1 %. The most goitrogenic component, oxazolidinethione, comprises about 65 % of the glucosinolate hydrolysis products of Regent, but only about 30 % of those of B. campestris varieties. The tannin content of rapeseed meals is 2-3 %. Experiments with pigs The digestibility and balance trials were performed with growing pigs, which were fed according to the energy standards scale of PARTANEN (1970). Barley meal was used as the basic feed and the diets were supplemented with minerals and vitamins as recommended in standards. The first experiment (1979) was carried out with four barrows, weighing during collecting periods 50-70 kg. The RSM comprised 30 % of the diets. The second experiment (1980) was carried out with three barrows, of liveweight 40-70 kg, using a 3x3 Latin square design. The palatability of RSM was very poor in 1980, and the proportion of RSM in the diets had therefore to be restricted to 20 %. The pigs were kept in metabolic cages allowing a separate collection of faeces and urine. The adaptation period before the first trial was about three weeks, the transition period 3-5 days, and both the standardization and collection periods 7 days. The animals were fed twice daily. The different ingredients were weighed separately and mixed with two volumes of water. Water was given freely after feeding. The faeces and urine were collected in the morning and samples of fixed amount were taken for analysis and stored frozen until analyzed. Sulphuric acid was added to the urine collection pail to keep the acidity under 307 pH 3. Feed spillages were collected and subtracted from the given feed. The pigs were weighed before and after the collection period. Dry matter determinations were made at 103°C, and the samples for analysis dried in vacuum at 50°C. Feeds and faeces were ground through a 0.5 mm screen. The analyses were made according to standard procedures. The digestibility of barley was determined by separate trial in each year and the digestibility of the RSM and RSC calculated by subtraction. The net energy values (f.u. = feed unit = 0.7 kg starch equivalent) were calculated using factors and models of NJF Feed Tables (ANON. 1969). The results were tested by one-way variance analysis and the differences between means by the Tukey-test ( STEELE and TORRIE 1960). Experiments with sheep Sheep trials were performed with three rams, average weight 45 kg, as a 3x3 Latin square design. The trials consisted of transition, standardization and collection periods, each of them lasting 7 days. The animals were kept in cages with a funnel for the collection of urine. During the collection period the sheep were provided with faeces-collecting harnesses. The feeding took place twice daily. Basic feed was 400 g hay and 250 g barley meal/d, plus minerals and vitamins according to standards. Hay and barley were of normal quality and their digestibilities were determined by separate trials. Amounts of RSM and RSC (Table 1) were 300 g/d (32 % of the diet). Water was unrestricted and its consumption was measured. The sheep were weighed before and after the collection period. Otherwise the experimental technique and the calculation of the results were essentially the same as for pigs. Results and discussion Experiments with pigs The commercial RSM has been evaluated for pigs in three successive years, the first study being reported in a earlier paper (SALO 1980). The results show the chemical composition and digestibility and thus the nutritive value of the domestic RSM to be approximately constant (Tables 1, 2 and 3). The observed net energy values for pigs in three successive years were 0.78, 0.80 and 0.79 f.u./kg DM, and the protein values 248, 281 and 291 g DCP/ kg DM, respectively. The digestibility of organic matter was equal to that reported in the Feed Tables of Sweden (ERIKSSON et al. 1972) and Denmark (ANDERSEN and JUST 1979), but a little lower than the corresponding data in Feed Tables of Norway (BREIREM and HOME 1970) and the Netherlands (ANON. 1979). The found digestibility of protein was slightly lower than that of the same feed tables. 308 Table 1. Chemical composition of rapeseed meals and cakes, % of dry matter. Rapeseed meals and cakes Crude Ether Crude Ash N-free protein extract fibre extract Exp. 1: Pigs Span-Torch, meal 37.9 2.8 14.2 8.2 36.9 Regent, meal 38.0 8.3 13.7 7.8 32.2 Exp. 2: Pigs and sheep Span-Torch, meal 37.6 2.4 14.8 8.0 37.2 » cakes 33.6 10.4 15.7 7.4 32.9 DF-15, cakes 35.0 9.6 14.3 8.1 33.0 Table 2. Digestibility coefficients of rapeseed meals and cakes for pigs. Exp. 1 Exp. 2 Span-Torch Regent Span-Torch Span-Torch DF-15 meal meal meal cakes cakes Organic matter 64.5 64.0 66.2 72.5 76.8 Crude protein 74.1 75.0 77.5 83.6 84.5 Ether extract 52.4C 77.9 d 21.8 77.9 81.4 Crude fibre 32.0 26.7 39.7 48.8 58.5 N-free extract 67.2 62.3 71.4 72.7 76.4 In all tables the significance of differences in the same experiment are; P<0.05 = a, b ; P