Vol 5(19961:157-166. Lysine supplementation of barley wet distillers’ solids diets for growing-finishing pigs Jarmo Valaja 1 , Hilkka Siljander-Rasi and Timo Alaviuhkola Agricultural Research Centre ofFinland, Swine Research Station, Tervamäentie 179, FIN-05840 Hyvinkää, Finland Asko Rantanen Primalco Ltd., FIN-05200 Rajamäki, Finland A growth experiment was conducted to study the effect of different lysine supplementation levels of barley wet distillers’ solids (WDS) diets on the performance and the carcass quality of pigs (25.5-95.5 kg live weight). A total of 160pigs were divided into four groups of 40 animals. Four pigs of the same sex were placed in each pen and fed one of the four experimental diets; a barley-soyabean meal (SBM) control diet (167 g crude protein (CP) /kg dry matter (DM) and 7.6 g lysine/feed unit (FU)) or three similar barley-WDS diets (204 g CP/kg DM) which were supplemented with synthetic lysine to contain 7.7, 9.2 or 10.7 g lysine/FU. Lysine supplementation linearly improved the daily weight gain (DG) and feed conversion ratio (FCR) of the pigs during growing (1-5 weeks) (p < 0.001), finishing (6th week onward) (p < 0.001) and the whole experimental period (p < 0.001). However, during the whole growing-finishingperiod the performance of the pigs levelled off at the lysine level of 9.2 g/FU and daily supply of 18.0 g, respectively(quadratic effect: p < 0.05 for DG and p < 0.01 for FCR). The pigs on the SBM diet grew faster and more efficiently than did the pigs on the WDS diets with similar lysine content (p < 0.05). Key words: swine, daily weight gain, feed conversion efficiency, amino acids, soyabean meal 1 Current address: Agricultural Research Centre of Finland, Institute of Animal Production, FIN-31600 Jokioinen, Finland ntroduction The amino acid composition ofgrain protein, and especially lysine content, is insufficient when compared to the requirements of growing pigs. Similarly, many industrial by-products, e.g. bar- ley wet distillers’ solids (WDS), originating from grain contain low amounts of lysine in their pro- tein (Näsi andAimonen 1992,Valaja etal. 1995). In pigs, the protein utilisation of the diets composed solely ofWDS is poor, because a large part of the protein is excreted via urine, where it increases environmental pollution (Valaja and Näsi 1996). However, the lysine supplementa- tion of WDS diets has increased protein utilisa- © Agricultural and Food Science in Finland Manuscript received January 1996 157 AGRICULTURAL AND FOOD SCIENCE IN FINLAND https://www.c-info.fi/en/info/?token=Nmt371DtBU0Rro_B.RgB5VQYhVSLJeidDYzG_Gg.gHQFHws-bJvGCKmgf4fys3PHG0n8iGOsegO_MTgDkEGiQ4ziTdKiHiB_IsX0_SWC-nRkcWlnsOPkd3-VNWf3MC_ay-u0xUuZuf2cNtzo0OCWUiCgNKE1dFkPxYgAz-n1PJoQfPTYlUqnYZ_k20Bqyq-rH5R9u70iWxtvYSkIGLCdVv0wHW7v9qF__ebz1dX8gw8Tb9FeaJ6iszDFUI42vbhEfkWP2p8YQVi81ThZE-U5U0GvsXTKp6geLgdlP4CoolMWFnR5Da5s6Jehpw-DDEsnbsLO_0LbQWi_D7PXJC8e3nEHIKWHHGvzvoshjgCuDMUAEckk12kAb2w Valaja, J. et al: Lysine supplementation ofbarley wetdistillers’ solids dietsfor growing-finishing pigs tion in pigs to the level of soyabean meal (SBM) (Valaja and Näsi 1996). Optimal amino acid bal- ance is needed for the effective utilisation ofdi- etary protein. Recommendations for dietary lysine supply derived from different sources can only be applied in situations similar to those in the experiments (Susenbeth 1995). No studies have been conducted to set the amino acid rec- ommendations for the Finnish pigs of high ge- netic potential fed diets composed of WDS. The performance of the pigs fed convention- al distillers’ feeds has been variable, mainly be- cause of the high fibre content and the differ- ences in the severity of the drying process (Ala- viuhkola 1978, Suomi 1980,Newman and Gras 1983). In the growth experiment with WDS, the performance of the pigs has been only satisfac- tory (Valaja et al. 1995). However, the digesti- bility of amino acids and protein in WDS has been high in the former experiments (Näsi and Aimonen 1992, Valaja and Näsi 1996, Buracze- wska et al. 1996). Because of the conflicting re- sults in the performance and digestibility exper- iments, more information was needed on the suit- ability of wet distillers’ solids for growing-fin- ishing pigs and the optimal lysine supplementa- tion of the diet. The objectives of the present experiment were to determine the effects of increasing lysine supplementation in WDS diets on the perform- ance and carcass quality of growing-finishing pigs and, to set an optimal lysine supply level for WDS. The performance responses of the pigs on the WDS diets were also compared to those of the pigs on the conventional SBM diet. Material and methods The growth trial was conducted with 160 grow- ing pigs mainly of Yorkshire (47.2%), Fl-cross- bred (Finnish landrace x Yorkshire; 14.5%), F- crossbred (Finnish landrace or Yorkshire x FI; 22.0%) or Finnish landrace (13.2%) origin. The pigs were divided into four similar groups of 40 animals each, based on breed, litter-origin, sex and live-weight, and were allotted at random to one of the four experimental treatments. Four pigs of the same sex were placed in each pen. Each treatment was tested with 10 replicates. The mean initial live weight of the animals was 25.5 (SE 0.28) kg. Barley-based experimental diets contained eitherSBM (diet 1) or WDS (diets 2, 3 and 4) as a protein supplement (Table 1). The level of pro- tein supplement in diets 1 and 2 was fixed to contain a similar amount of lysine (7.6 g/feed unit, feed unit calculated according to Tuori et al. 1995). The lysine contents were below the recommendations for growing pigs because die- tary lysine mainly originated from the feed in- gredients. The other WDS diets (3 and 4) were similar to diet 2, but were fortified with synthet- ic L-lysine-hydrocloride (Eurolysine) to provide 9.2 and 10.7 g lysine/FU (2.9 and 5.1 g added lysine/FU), respectively. The experimental diets also contained minerals and vitamins to fulfill the requirements of growing pigs (Tuori et al. 1995). The crude protein (CP) contents of the diets 1,2, 3 and 4 were 167, 202, 204 and 206 g/kg DM, respectively. The WDS was delivered weekly from the Alko Ltd. Koskenkorva plant during the experi- ment. It was the product of an integrated starch- ethanol process, which uses barley as a raw ma- terial (Näsi 1988). In this process, WDS was separated from wet distillers’ solubles by cen- trifugation. It was preserved with sodium benzoate (3 g/kg) and stored at the Swine Re- search Station as in the previous experiment (Valaja et al. 1995). The pigs were housed in partially slattedpens with concrete floors. They were fed twice daily and had free access to water. Feeds were given on a restricted scale in relation to age (1.2-2.8 FU/day/animal); the daily allowance was in- creased by 0.2 FU/week in the beginning, and by 0.1 FU/week after the eighth experimental week. Feed consumption was recorded daily and the pigs were weighed at two week intervals. When the pigs reached 97 kg, they were sent to an abattoir. The carcass dissection of the pigs 158 AGRICULTURAL AND FOOD SCIENCE IN FINLAND Vol. 5 (1996): 157-166. Table 1.Composition of diets containing wetdistillers’ solids supplemented with synthetic lysine for growing pigs and their calculated analysis. Diet 12 3 4 Component, g/kg DM Barley 843 753 751 749 Wet distillers" solids 209 209 209 Soyabean meal 123 - - - L-lysine-HCI 0.7 2.9 5.1 Limestone - 4.2 3.3 3.3 Minerals and vitamins" 34 33.3 33.3 33.3 Calculated analysis Crude protein, g/kg DM 167 202 204 206 Digestible crude protein, g/FU 127 151 153 154 Lysine, g/FU 7.6 7.7 9.2 10.7 Lysine, g/16gN 5.0 4.3 5.0 5.8 Digestible lysine, g/FU 6.0 5.9 7.4 9.0 Digestible lysine, g/16 g N 3.9 3.3 4.0 4.9 Methionine+Cystined , g/FU 4.7 8.7 8.7 8.7 Threonine", g/FU 5.2 6.3 6.3 6.3 Calcium, g/FU 8.0 9.0 8.7 8.7 Phosphorus, g/FU 6.7 7.2 7.2 7.2 NEb , MJ/kgDM 10.2 10.3 10.3 10.3 Feed units', FU/kg DM 1.10 1.11 1.11 1.11 a Supplied per kg of diet DM: Ca 7.6 g; P 3.4 g; Mg 0.3 g; NaCl 3.5 g; Fe 153 mg; Zn 92 mg; Mn 44 mg; Cu 34 mg; Co 1.2 mg; 10.2mg; Se 0.14 mg; vitaminA48601U; vitamin D 3 780 mg; vitamin E24 mg; thiamin 1.9 mg; riboflavin 6.8 mg; pyridoxine 3.9 mg; pantothenic acid 14.6 mg; folic acid 3.9 mg; B 12- vitamin 19 pg; biotin 136 pg. b NE calculated according to Tuon et al. (1995). c Feed unit = NE/9.3. d the contents obtained from Valaja et al. (1995). was performed according to Valaja et al. (1993). The WDS diets were composed of a mixture of dry ingredients (barley, synthetic lysine and min- erals and vitamins) and WDS which were weighed separately and mixed just before feed- ing in a trough. The SBM diet was a meal-type mixture and it was mixed with water (1:2) be- fore feeding. The allowance ofWDS was adjust- ed weekly according to the DM content of each batch. A standard feed analysis was conducted for barley, WDS and SBM (AOAC 1984). Ether ex- tract was analysed after acid hydrolysis. During the experiment, the DM and CP contents ofWDS were determined from every batch (n = 34) and the whole feed analysis of WDS was determined from seven pooled samples. The analyses were performed in duplicate. The amino acids of WDS were determined from seven pooled samples by high-performance liquid chromatography after hydrolysis with 6 N HCI at 110°C for 23 h. The amino acids ofbarley and SBM were determined by gas chromatography after hydrolysis with 6 N HCI at 110°C for 20 h (Näsi and Huida 1982). The data were subjected to analysis of vari- ance using the GLM procedure of SAS (1985). The model used to analyse the data was: y«M=/|+t i+s ) +( t*s )u+e iJk where y ijk| is the dependent variable; is the 159 AGRICULTURAL AND FOOD SCIENCE IN FINLAND Valaja, J. et ai: Lysine supplementation ofbarley wet distillers’ solids diets for growing-finishing pigs Table 2. Chemical composition of wet distillers’ solids, soyabean meal and barley used in the experiment. Wet distillers' solids Soyabean meal Barley Mean SD Min. Max. No of observations 7 Dry matter, g/kg 192" 16.4 162 250 877 861 Crude protein, g/kg DM 537" 25.9 442 575 512 126 Ether extract, g/kg DM 65 3.1 61 71 29 22 Crude fibre, g/kg DM 30 4.2 22 32 65 49 N-free extract, g/kg DM 320 36.0 285 385 331 776 Ash, g/kg DM 62 5.3 56 68 63 27 Amino acids, g/160 g N Lysine 40 3.2 36 45 64 39 Threonine ND 41 29 Methionine ND 10 14 Histidine 19 1.3 17 21 23 18 Leucine 67 3.3 62 71 77 62 Isoleucine 42 2.1 38 44 51 35 Phenylalanine 56 2.7 51 59 53 46 Arginine 51 11.0 41 63 66 45 ND, Not determined. SD, Standard deviation. a Number of observations was 34. overall mean; t, is the effect of the treatment; s, is the effect of the sex; (t*s).. is the effect of the interaction between the treatment and sex.; e...’ ijk is a normally distributed random variable. Ini- tial weight was used as a covariate when testing the growth performance. The mean of the pen was used as an experimental unit in all the anal- yses. The linear and quadratic effects of lysine level were tested with orthogonal polynomials. The SBM diet was tested against each WDS diet with the Dunnett t-test . Results During the experiment 34 batches of WDS were used. The average DM, CP and lysine contents of WDS batches were 192 g/kg, 537 g/kg DM and 40 g/160 g N, respectively (Table 2) and they varied from 162 to 250 g/kg, 442 to 575 g/kg DM and 36 to 45 g/160 g N, respectively. The variation was the highest in DM and lysine con- tent. One animal from treatment 4 was lost due to an intestinal obstruction and four animals were removed from the experiment because of retard- ed growth (two pigs from treatment 4) and tail biting (two pigs from treatment 3). The death and removals were not related to the experimen- tal treatments. Two pens of the excluded pigs were also removed from the feed consumption data set because the feed consumption of the re- maining pen-mates could not be precisely esti- mated. By mistake an uneven number of pens per sex was divided in treatment 1 (4 and 6 pens for gilts and castrated male pigs, respectively). Refusals of the diets were negligible. However, it was noticed that the pigs on WDS diets (2, 3, and 4) tended to eat their daily allowance more slowly than those on SBM diet did. The calculated daily lysine supply was main- 160 AGRICULTURAL AND FOOD SCIENCE IN FINLAND Vol. 5 (1996): 157-166. Table 3. Performance of the pigs between weeks 1 and 5 and from the 6th week onward on diets composed of soyabean meal or wet distillers’ solids supplemented with synthetic lysine (LS-means of the treatments are presented). Treatment 1 2 3 4 SEMb Effect of lysine level Protein suppl. SBM WDS WDS WDS Linear Quadr. Lysine level g/FU 7.6 7.7 9.2 10.7 1-5 weeks Initial weight, kg 24.6 24.8 24.8 24.7 0.28 NS NS Final weight, kg 46.5 43,1“ 47.2 48.0 0.60 *** * Daily weight gain, g 662 557“ 681 708 17.4 *** * Daily lysine intake, g 11.9 10.6“ 12.7* 14.8* 0.14 *** NS FCR, FU/kg gain 2.45 2.84“ 2.34 2.31 0.088 *** * FCR, NE MJ/kg gain 22.7 26.3“ 21.7 21.4 0.81 *** * 6th week onward Initial weight, kg 46.5 43.1“ 47.2 48.0 0.60 *** * Final weight, kg 99.3 99.4 99.3 100.2 0.46 NS NS Experimental days 60.4 68.1“ 57.2 56.5 1.79 *** * Daily weight gain, g 889 847 918 931 13.2 *** o Daily lysine intake, g 19.2 17.9“ 21.0“ 24.5* 0.27 �** NS FCR, FU/kg gain 2.96 3.03 2.79* 2.81* 0.041 *** * FCR, NE MJ/kg gain 27.6 28.1 25.8* 26.0* 0.38 *** * Significance: NS = non-significant, o = p