Maataloustieteellinen Aikakauskirja Vol. 56: 227—238, 1984 Nutritive value and metabolic effects of whey protein concentrate and hydrolysed lactose for growing pigs MATTI NÄSI Department of Animal Husbandry, University of Helsinki, SF-00710 HELSINKI, Finland Abstract. In two digestibility and balance trials with growing pigs, whey protein concen- trate (WPC) was compared as a protein supplement with casein (CAS) and dried skim milk (DSM), and, 30 % lactose (40 % dried whey, DW) was compared as a sugar supplement with the same amounts of hydrolysed lactose (HYLA) and sucrose (SUC). The effects of these supplements on protein and mineral metabolism of the pigs were investigated, WPC contained 42.2 % crude protein and had a high content of lysine, 8.6 g, and sulphur containing amino acids: cystine 2.8 and methionine 2.2 g/16 g N, These exceeded the values for DSM. The hyd- rolysing degree of the enzymatically treated lactose syrup was 73 %. WPC had high crude protein digestibility, 99.1 % as compared to 95.4 for CAS and 95.0 % for DSM. Dried whey had low crude protein digestibility, 72.5 %. The amino acids in the WPC diet were highly digestible, but low values were obtained for the DW diet. On the WPC diet, nitrogen retention was higher than with the other protein supplements (P > 0.05), urinary urea excretion was low and the biological value very high. On a combination ofWPC and HYLA protein utilisa- tion was higher than on dried whole whey. On the diets supplemented with different sugars, none of the blood parameters differed statistically significantly (P > 0.05) and all values lay within the reference range. Water intake was on average 49 °/o greater on diets with sugar supplements than without. Urinary excretion of reducing sugars averaged 40.2, 8.3 and 6.6 g/d on the HYLA, SUC and DW diets, while on the diets without sugar supplements the val- ues were 0.8—1.2 g/d. The following mean daily mineral retention values were obtained: P 4.0 g, Ca 5,9 g. Mg 0,4 g, Na 1.9 g, K 2.9 g, Fe 27 mg, Cu 6.4 mg, Zn 65 mg and Mn 4.0 mg. The surplus Na and K on the DW diet were excreted in the urine and the pigs did not have diarrhoea. Introduction With the expansion of cheese manufactur- ing in Finland, increased amounts of whey are supplied for animal feeding, while minor amounts of whey products are used in the food industry. In 1983, the total production of whey was 650 mill, kg, of which ca. 20 *Vo was used directly in liquid form by farm animals, the remainder being used to prod- uce 26 mill, kg dried whey (Anon. 1983). Li- quid whey contains a high proportion of Index words: whey, whey proteins, dried whey, lactose, hydrolysed lactose, pig feeding, protein supplements. 227 JOURNAL OF AGRICULTURAL SCIENCE IN FINLAND https://www.c-info.fi/en/info/?token=h2-Td4VXV-Yswttb.5_xZHO-LRVitCCoGDufoPg.AcGVOLrsPQyA6Xc1Q_x9c5g2dOZ8tFuaKb0h5zWM2A75GITZpC-f9hzwHDqF8tOrNHSa0MTyu862uyT3erFVK4ylcBkkWOpcLAnu_3tddlozBItGsb3jP-WAyIsE6DdFvutC6sJnTg_oG_WQRYG34hpSDQvssXAXQ5GgiMM water and only 5—7 % dry matter, which makes drying very expensive. Whey solids contain about 75 % lactose, relatively little protein, 13 %, and 9 °/o ash. Whey deterio- rates rapidly and this, together with high transport costs, restricts its extensive use as a liquid feedstuff. Furthermore, large whey supplements, over 30—40 % of energy in- take, cause slow growth and digestional dis- turbances in growing pigs, due to the high lactose and mineral contents of whole whey (Barber et al. 1978, Fevrier 1978). Recent technological developments, such as enzymic hydrolysis of lactose, ultrafiltration and re- verse osmosis, allow concentration of the protein and reduction of the lactose and mineral contents, thus eliminating the prob- lems encountered when large amounts of whey are used in pig diets (Harju 1984). Large amounts of hydrolysed lactose syrup and whey protein concentrate have been given to pigs with good results (Alaviuhko- la et al. 1980, Alaviuhkola 1982, 1984). The present physiological experiments were undertaken to assess the nutritive value and utility of some new whey products in pig diets and theireffects on protein and mineral metabolism. Materials and methods Two digestibility, nitrogen and mineral balance experiments were conducted with three castrated Landrace pigs weighing 38—71 kg in trials of 3 X 3 Latin square de- sign, to determine the nutritive value and metabolic effects of some whey products of the new process technology. In one experi- ment ultrafiltrated spray-dried whey protein concentrate (WPC) was compared as a pro- tein supplement with hydrochloric acid-pre- cipitated spray-dried casein (CAS) and spray- dried skim milk (DSM). In the other experi- ment, spray-dried whole whey (DW) was compared as a lactose supplement with suc- rose (SUC) and Hydrolact L-50 enzyme hy- drolyzed lactose syrup (HYLA), hydrolyzing min. 73 %. The experimental substances were normal products of the firm Kuivamai- to Oy, Lapinlahti. Six isonitrogenous diets were prepared, using barley meal enriched with mineral mixture (Seleeni-Terki, 40 g/d) and vitamin mixture (Vitamiini-Nasu, 15 g/d), the percentages of supplements the in the diets being as follows: The daily rations were 1.8, 2.2 and 2.6 kg, on average 97.3 g DM/kg W 0 75 . The bar- rows were kept in metabolism cages, which allowed separate quantitative collection of urine and faeces. They were fed a slurry of Ikg diet and 1.5 litre water twice daily. Each experiment lasted 16 days, consisting of a 4-day transition period, a 6-day accommon- dation period and a 6-day collection period. Blood samples were taken from the ante- rior vena cava after each collection period before morning feeding. The treatment of samples and the methods used were the same as described by Näsi and Tanhuanpää (1981). The chemical analyses of feeds and faeces were performed according to the offi- cial procedures. Amino acids were deter- Protein supplements Sugar supplements WPC CAS DSM HYLA SUC DW Barley 88 94.5 85 45 45 49 Whey protein cone. 12 —2525 11 Casein 5.5 Skim milk powder Dried whey Hydrol. lactose syrup ——3 O Sucrose 228 229 mined on the diet ingredients and faeces with a Technicon TSM autoanalyzer. Minerals were measured with a Varian Techtron AAIOOO atomabsorption spectrophotometer. Phosphorus was determined by the method of Tayssky and Shorr (1953), sodium and potassium concentrations were determined by flame photometer (Corning 435). The os- molality of the urine was analysed by the freezing point depression method with a Fis- ke osmometer. Results and discussion The chemical composition of the experi- mental feeds is shown in Table 1. The whey protein concentrate had a proximal composi- tion comparable to that of dried skim milk. Whey protein is mostly composed of /3-lacto- globulin and a-lactalbumin, thus differing in its amino acid profile from casein and skim milk, in which casein constitutes approxima- tely 80 % of total protein (Fox 1982). Whey- Table I. Chemical composition of the experimental feeds. In dry matter Barley Dried Casein Dried Whey Hydrol. skim whey prot. lactose milk cone. syrup Dry matter, % 88.0 95.6 88.6 94.1 95.5 56.6 Ash, % 2.8 8.4 3.3 10.4 6.0 2.3 Crude protein, 0.05). Forsum (1975) reported decreased true protein digestibilities when dietary lactose increased. However, Eggum (1973) reported that lactose does not affect the digestibility of proteins. On the WPC, CAS and DSM diets reducing sugars were excreted in urine of the pigs at the rates of 1.1, 0.8 and 1.2 g/d, respectively, and on the HYLA, SUC and DW diets at the rates of 40.2. 8.3 and 6.6 g/d. The excretion on the HYLA diet was remarkably high compa- red with that on the diets with other sugar supplements. The water intakes were increa- sed on the diets supplemented with sugars; on the WPC, CAS, DSM, HYLA, SUC and DW diets they averaged, respectively: 4.35, 4.38, 4.68, 6.81, 5.80 and 7.43 kg/d. The overall amino acid digestibilities were higher on the WPC diet than on the CAS or DSM diets, the CAS diet giving the lowest values. This diet had significantly (P < 0.05, P < 0.01) lower digestibilities than the WPC diet, but not the DSM diet, for aspartic acid, isoleucine, leucine, lysine and threonine. The diet including DW had lower digestibilities for the most essential amino acids than the diets supplemented with other sugars (P > 0.05, P < 0.01). On the DW diet, it is possible that not all the lac- tose can be absorbed in the small intestine and that part is fermented in the large intes- tine, thus lowering the apparent amino acid digestibilities. But the low lysine content of DW indicates thermal denaturation of pro- tein during drying and reduced digestibility and availability. The pigs on the DW diet had slightly loose and foamy excrements, but no diarrhoea was observed and the DM con- tent of the faeces on the various diets was 29.2, 29.5, 31.3, 31.8, 31.8 and 29.7 %. The digestibility of crude protein in WPC, calculated by the difference method, was 99.1 %, compared to 95.4 for CAS and 95.0 % for DSM (Table 3). Dried whey had rather low CP digestibility, 72.5 % com- pared, to the other milk proteins. Just et al. (1983) also received a low value, 78 %, for the crude protein digestibility of DW, while Salo et ai. (1982) reported the higher value of 90 %. However, the digestibility of the organic matter of dried whey in the present study was similar to that reported by Han- kahan (1971) and Just et al. (1983). The whey protein concentrate had a FU value 10.5 % higher than that of dried skim milk, and hydrolysed lactose syrup also had a high value, only 3.5 % lower than sucrose. The high feed values of WPC and HYLA ob- 230 Table 2. Digestibility coefficients of nutrients in diets supplemented with various milk protein sourcesand with various sugars. Per cent Protein supplements Sugar supplements Whey prot. Casein Dried skim Hydrolysed Sucrose Lactose concentrate milk powder lactose (Dried whey) x s.d x s.d x s.d x s.d x s.d x s.d Dry matter 82.8 1.9 81.5 2.0 82.8 2.5 89.2" 0.8 90.3" 1.5 86.0* 1.8 Organic matter 84.5'" 1.7 83.3' 1.9 84.6» 2.2 90.6' 0.6 91.6" 1.3 87.7' 1.7 Ash 48.5 1.9 42.5 2.5 50.9 4.2 61.8 1.8 61.3 3.7 66.3 2.4 Crude protein 83.3 2.7 81.2 4.1 82.6 5.0 85.7 1.4 89.7 2.3 80.7 4.6 True protein 87.6 1.2 86.1 3.1 86.9 3.7 89.9 0.7 92.4 1.1 85.4 3.2 Crude fat 81.9 3.5 78.0 4.7 77.6 5.8 83.6 3.2 88.4 3.3 81.4 9.1 Crude fibre 32. 5b 1.1 30.6' 1.5 31.1' 0.1 28.7 1.6 26.4 5.8 24.4 5.0 NFE 89.3 1.2 88.8 1.1 89.6 1.2 94.4'" 0.5 94.6b " 0.7 92.5' 0.9 Amino acids Alanine 79.3 2.8 70.6 6.4 72.1 11.0 81.0"> 1.2 87.6' 2.6 74.5" 4.8 Arginine 89.2 2.7 87.7 2.9 87.7 4.2 86.2' 3.4 90.3' 1.9 79.3b 2.6 Asparticacid 83.3' 2.2 75.2" 5.0 78.5'" 7.8 87.9'" 1.3 91.6' 2.0 82.8" 3.6 Cystine 95.7 3.7 93.6 5.6 93.9 5.4 96.7 1.8 97.0 1.3 94.4 1.3 Glutamic acid 91.1 0.5 89.4 2.4 90.4 3.6 91.7'" 0.8 94.4' 1.3 88.8" 2.3 Glysine 81.2 1.8 77.2 3.8 77.9 7.7 77.8 1.4 84.8 2.6 70.0 4.7 Histidine 79.2 3.8 74.5 3.0 77.6 5.6 82.2= 0.6 85.6" 1.6 77.4f 1.9 Isoleucine 88.4' 0.8 84.1" 3.6 85.8'b 4.9 90.0»" 1.1 93.6» 1.2 87.4" 2.1 Leucine 89.5» 1.2 86.1 b 2.7 88.4'" 3.9 91.0* 0.8 93.9» 1.1 88. 2b 2.2 Lysine 84.8" 1.8 78.4' 5.0 83.3d 6.0 89.3» b 1.1 93.0» 1.4 83.7" 3.2 Methionine 93.6 1.0 92.4 2.1 93.5 2.0 94.3 1.1 96.0 1.0 91.1 1.5 Phenylalanine 87.9 1.5 87.7 2.5 88.7 3.3 87.7» b 0.8 91.3» 1.4 85.3" 2.4 Serine 88.1 1.0 84.7 3.2 85.2 5.9 90.0» 1.2 93.0» 1.5 86.5' 1.8 Threonine 87.1» 1.8 79.7" 4.8 81.4»" 7.5 90.5'" 0.9 93.7' 1.3 87.3" 2.3 Tyrosine 90.5 1.6 90.7 0.7 90.9 2.6 89.0 0.7 92.5 1.2 85.4 3.2 Valine 86.5 U 83.7 3.2 86.3 5.4 87.9 0.9 92.1 1.5 84.7 2.9 Means with different letters were significantly different: a,b (P < 0.05); c,d (P < 0.01). 231 Table 3. Digestibility coefficients of experimental feeds calculated by the difference and their feed values. Protein supplements Sugar supplements Whey Casein Dried Hydrol. Sucrose Lactose protein skim lactose (Dried concentr. milk whey) Degestibility Dry matter 96.7 93.1 94.0 96.0 99.2 89.8 Ash 99.9 99.9 99.6 72.1 80.6 Organic matter 97.2 93.4 95.0 96.4 98.9 91.1 Crude protein 99.1 95.4 95.0 72.5 True protein 98.1 95.5 95.0 78.5 Crude fat 98.8 99.9 90.0 74.4 NFE 93.7 68.9 95.0 99.9 99.9 96.8 Feed values FU/kg DM 1.36 1.26 1.23 1.38 1.43 1.19 kg/FU 0.77 0.90 0.85 1.28 0.70 0.89 DCP % in DM 41.8 85.4 36.4 12.1 DCP g/FU 307 680 296 102 ME MJ/kg DM (Just) 18.28 19.37 16.56 16.67 17.17 14.89 NE MJ/kg DM (Just) 11.83 12.65 10.54 10.62 11.00 9.29 NE FU/kg DM (Just) 1.53 1.64 1.37 1.38 1.43 1.20 ME MJ/kg DM (Axels.) 17.44 17.59 15.80 16.66 17.17 14.64 tained here are in good agreement with the results of pig growth trials in which soybean fish meal was replaced with WPC, which improved the daily gain by 9 % and also the feed conversion efficiency by 9 % (Alaviuh- kola 1982). Replacement of barley with HYLA at the levels of 30 and 45 % of the feed units improved daily gains by 8 and 4 °7o, while DW inclusion gave a 3 % increase (Alaviuhkola et al. 1980). Good perform- ances were also obtained in pig feeding ex- periments, when WPC was used as a protein supplement and the ration contained 28.5 % and 52.4 % HYLA, but pigs receiving over 70 % whey products in their diets showed 6 % lower daily gain (Alaviuhkola 1984). With diets containing 60 % hydrolysed lac- tose or untreated whey, Fevrier (1980) found that hydrolysed lactose raised the energy and protein digestibilities from 85.4 to 87.5 % and from 74.8 to 80.6 %. Table 4 presents data on the nitrogen bal- ance with the different diets. The WPC diet had the highest nitrogen retention, 25.5 g/d, which exceeded the value for the CAS diet by 7.9 % and for the DSM diet by 2.7 %. A wet carboxy methyl cellulose precipitated (CMC) whey product gave still higher retention of nitrogen and a higher biological value (Nasi et al. 1982) than the WPC product in the present study. Urinary urea excretion on the WPC diet was 14 % and 18 % lower than on the CAS and DSM diets, indicating very good amino acid availability and balance in the WPC diet. The biological value was also high, 73.4 %. Consequently, ultrafiltration of whey gives a protein source which is largerly undenaturalized (Forsum 1975). The DW diet had the lowest values for nitrogen utilization. This was in accordance with the daily gains, which averaged 910 g for the other diets and 750 g for the DW diet. How- ever, Eggum (1973) found that in most cases the biological value was improved by lactose supplements. Thorbek et al. (1961) also ob- tained an higher protein deposition in 30— 65-days-old piglets fed casein + lactose than in animals given casein + glucose or sucrose. Whey powder is produced by evaporation and drying at comparatively high tempera- 232 tures, and lactose is a reducing sugar, which can react with lysine, with a consequent Maillard reaction and other denaturation ef- fects on the amino acids. Whey proteins are among the highest- quality natural proteins available; in experi- ments with rats the protein efficiency ratio (PER) of whey protein was approximately 20 % greater than the PER of casein (De mott 1972, Forsum 1974, 1975), 10 % great- er than the PER of skim milk on wheat diets (Womack and Vaghan 1972). The balance data of the present investigation accord with the improved performance of pigs fed WPC instead of soybean fish meal protein with an equivalent amino acid supply (Alaviuh- kola 1982). They also agree with the meta- bolic performances of piglets on diets with casein to whey protein ratios ranging from 80 :20 to 0 : 100; in that study the CAS : WPS ratio of 40 : 60 gave the highest rate of gain, the urea N in total urinary N was inversely related to the proportion of whey protein in the diet, and the plasma urea was low throughout (Henschel et al. 1983). The pigs on the WPC diet had a signifi- cantly (P < 0.05) higher potassium content in the blood than the pigs on the other diets (Table 5). The alkaline phosphatase of the pigs on the WPS diet was lower than in the pigs on the DSM diet (P < 0.05). In the pigs on the diets supplemented with different sug- ars, none of the blood parameters showed statistically significant differences (P > 0.05). Blood glucose was similar to that in the pigs not receiving sugar supple- ments. Rerat et al. (1984) found that a lac- tose supplement of 400—1600 g/d in the diet, as opposed to sucrose or glucose, re- sulted in only a small and constant amount of reducing sugars in the portal blood and that after the meal the sugar level remained above the initial value longer than with the other sugars. Although the pigs on the DW diet had high intakes of sodium and potas- sium, their blood values did not differ from those of the other pigs. The blood values in Table 4. Nitrogen balance and biological value of diets supplemented with various milk protein supplements or sugar supplements. Protein supplements Sugar supplements Whey Casein Dried Hydrol. Sucrose Lactose protein cone. skim milk lactose (Dried whey) x s.d x s.d x s.d x s.d x s.d x s.d Nitrogen Intake, g/d 46.2 7.7 47.0 8.3 47.8 8.3 50.9 9.0 50.6 8.8 54.2 9.7 Faeces, g/d 7.6 0.4 8.6 0.7 8.6 1.0 7.2 1.3 5.1 0.6 10.3 2.0 Absorbed, g/d 38.6 7.5 38.4 8.7 39.7 8.9 43.6 8.0 45.5 9.1 43.9 9.2 Urine, g/d 13.1 2.9 14.9 5.2 15.0 5.8 19.1 9.9 21.6 11.7 20.4 9.9 Retained, g/d 25.5 4.7 23.5 3.9 24.8 3.2 24.5 3.8 23.9 3.4 23.6 2.4 % of intake 55.1 1.0 50.2 3.5 52.1 2.9 49.7 14.9 48.7 13.0 44.6 9.7 % of absorbed 66.2 1.5 61.9 6.0 63.3 6.4 57.9 17.1 54.6 15.7 55.5 13.4 N retained, g/kg Wo7 ' 1.24 0.02 1.16 0.12 1.21 0.10 1.17 0.35 1.16 0.34 1.14 0.27 Urea excretion, g/d 20.6 3.5 23.5 8.7 24.4 9.6 28.2 17.8 36.1 24.7 34.3 16.7 Urea excretion, g/kg W»- 7S 1.00 0.03 1.13 0.16 1.15 0.26 1.23 0.65 1.59 0.78 1.54 0.50 Creatinine, g/d 2.03 0.45 1.92 0.65 2.15 0.74 2.20 0.58 2.42 0.97 2.60 0.65 Biological value 73.4 1.6 69.4 5.6 70.6 6.3 65.1 16.0 61.8 14.8 62.8 12.7 233 234 Table 5. Blood composition in pigs fed diets supplemented with various milk-based protein sourcesor sugaradditions. Protein supplements Sugar supplements Whey Casein Dried Hydrol. Sucrose Lactose protein cone. skim milk lactose (Dried whey) x s.d x s.d x s.d x s.d x s.d x s.d PCV, % 38.3 2.8 37.1 3.6 39.0 3.2 35.4 3.7 33.6 10.0 35.8 0.4 Hb, g/1 123.9 8.5 121.8 15.3 128.2 14.9 122.5 13.9 116.2 20.1 124.3 14.8 Plasma glucose, mmol/1 6.5 0.6 7.0 2.1 6.6 1.5 6.3 0.4 5.8 0.6 6.0 0.1 Urea, mmol/1 2.3 0.1 2.1 0.2 2.6 0.5 2.7 1.2 2.1 0.4 2.5 1.4 Total protein, g/1 61 3 60 1 62 6 60 3 63 5 59 5 Albumin, g/1 39 2 38 5 38 6 39 4 40 1 39 6 Creatinine, mmol/1 127 6 121 3 119 15 121 13 120 13 115 4 Sodium, mmol/1 147 2 148 1 146 1 147 1 145 3 143 3 Potassium, mmol/1 4.7» 0.6 4.1" 0.4 3.8b 0.5 4.4 0.8 3.9 0.2 4.4 0.7 AP, 6.1" 2.1 6.7»" 0.7 6.8a 2.1 7.7 1.7 5.7 1.9 6.7 2.5 Alat, jikat/1 0.62 0.05 0.61 0.08 0.69 0.26 0.58 0.03 0.47 0.12 0.64 0.07 Asat, /ikat/1 0.93 0.16 0.98 0.15 1.04 0.24 0.70 0.20 0.71 0.13 0.74 0.10 CK, 23.9 14.4 17.0 10.3 21.0 14.2 16.2 2.5 19.4 7.7 15.5 14.6 7GT, 1.18 0.86 0.98 0.47 1.06 0.56 0.78 0.17 0.90 0.52 0.95 0.85 LDH, 21.6 4.4 23.9 8.9 26.0 6.7 17.2 1.6 18.0 7.6 19.7 6.6 Means with different letters were significantly different: a,b (P < 0.05); c,d (P < 0.01). the present study correspond fairly closely to the results obtained in other experiments in which the diets were supplemented with sugar alcohols or whey protein product (Na- si and Tanhuanpää 1981, Näsi et ai. 1982), and all parameters lie within the reference ranges (Schmidt 1979). The mineral metabolism was studied by measuring intake, and faecal and urinary excretion, and using the results to calculate absorption and retention (Table 6). The pigs received the same mineral supplements and the differences in the intakes were due to dif- ferences the mineral composition of the diets. The absorption of P and Ca averaged 50—51 %, that of Mg was very low, 25 %, and the values for Na and K were high, 89—79 %. The overall digestibilities of the trace elements were low, 8—37 %. Urinary excretion of P, Ca and Mg and also that of trace elements was low, while surplus Na and K were voided in the urine. Water intake was about 40 % higher in the pigs on the DW diet than in the pigs on the CAS diet, on the latter diet the pigs received 3.7 g Na/d and 11.3 g K, compared to 11.6 and 32.8 g/d, respectively, on the DW diet. Urinary osmo- lalities on the different diets were 529, 515, 493, 337, 484 and 463 mosm/kg urine and were not higher in the pigs voiding surplus K and Na. The urine excretion was higher on the diets with high mineral supplies, averag- ing 2.31,2.36, 2.82, 5.52, 4.17 and 5.58 kg/d on the WPC, CAS, DSM, HYLA, SUC and DW diets, respectively. High intakes of K and Na did not lead to diarrhoea. The following average daily retention val- ues were obtained for the pigs on the various diets: P 4.0±0.7 g, Ca 5.9±1.2 g, Mg 0.4±0.1 g, Na 1.9 + 0.4 g, K 2.9±0.8 g, Fe 27 ±l4 mg, Cu 6.4 + 2.1 mg, Zn 65 ±24 mg, Mn 4.0 + 2.9 mg. The retention of P, Ca and Mg was a little higher on the diets including lactose, but the differences were not signif- icant (P > 0.05). Na and K retention was al- most independent of the level in the diet. Lactose in the diet generally stimulates the mineral absorption and the minerals in milk products are readily available (Schingoethe 1976). The rates of absorption and retention obtained for the various minerals obtained in the present study are in good agreement with the results presented recently by Jorgensen and Fernandez (1984). Acknowledgements. Thanks are due to Miss Irma Klemetti for technical assistance. References Alaviuhkola, T. 1982. Heravalkuainen sopii sianlihan- tuotantoon. Karjatalous 58 (12); 35—36. 1984. Användning av vassleproducter till slaktsvin. Fodrets koncentrationsgrad till svin ur foder- och avelssynpunkt. NJF Seminarium Nr 57 12: I—6. —, Harju, M., Heikonen, M. & Kreula, M. 1980, The effect of the hydrolysis of lactose in whey on its value in the feeding of growing-finishing pigs. Acta Agric. Scand. 30: 13—16, Anon. 1983. Suomen osuusmeijerien liiketilasto LXXX. Helsinki 75 p. Barber, R.S., Braude, R., Michele, K.G. & Pittman, R.J. 1978. The nutritive value of liquid whey, either sour or sweet, when given in restricted amounts to the growing pig. Anim. Feed Sci. Technol. 3: 163—177. Demott, B.J. 1972. Nutritional value of casein and whey protein. Food Prod. Dev. 6: 88. Erbersdobler, H.F. 1983. Protein utilization and amino acid availability in milk products after treatment. Kie- let Milchwirtsch, Forschungsber. 35: (3) 301—311. Eooum, 8.0. 1973. A study of certain factors influenc- ing protein utilization in rats and pigs. Beretn. 406. National Institute of Animal Science. Fevrier, C. 1978. Use of dried whey in pig diets. I In- teraction with the dietary protein level according to growth stage and sex. Ann. Zootech. 27: 195—210. 1980. Growth and body characteristics of 20—100 kg pigs as affected by the intake of large untreated or hydrolysed whey concentrate. Ann. Nutr. Aliment. 34: 22—23. 235 Table 6. Mineral balance in pigs fed diets supplemented with various milk based protein sources of sugar additions. Protein supplements Sugar supplements Overall WPC CAS DSM HYLA SUC DW mean s.d. Phosphorus Intake, g/d 9.9b 9.8" 11.1' 11.0' 8.4* 13.2' 10.6 1.9 Faeces, g/d 5.1 4.9 5.7 s.o'* 3.8« 7.3' 5.3 1.8 Absorbed, g/d 4.8 4.9 5.4 6.0 4.6 6.0 5.3 1.1 Urine, g/d 1.1 1.6 1.6 1.6 0.5 1.4 1.3 0.7 Retained, g/d 3.8 3.3 3.9 4.5 4.1 4.6 4.0 0.7 % of intake 38 34 34 41 49 35 38 6 % of absorded 88 68 72 75»' 91» 78" 77 9 mg/kg WO7S 184 166 187 207 197 217 193 27 Calcium Intake, g/d 10.8b " 9.7" 12.2" 12.4" 12.2» 16.2» 12.3 2.2 Faeces, g/d 5.2 4.6 6.0 5.7" 5.0" 9.1« 5.9 1.6 Absorded, g/d 5.6 5.1 6.2 6.7 7.2 7.1 6.3 1.3 Urine, g/d 0.2 0.2 0.2 0.4 0.7 0.8 0.4 0.3 Retained, g/d 5.4 4.9 6.0 6.3 6.6 6.2 5.9 1.2 % of intake 50 50 49 51 54 38 49 8 % of absorded 96 96 96 94» 91" 88"' 93 4 mg/kg W° 7! 264 244 287 290 309 291 281 30 Magnesium Intake, g/d 3.3' 3.3* 3.4' 2.8" 2.7" 3.8* 3.2 0.5 Faeces, g/d 2.6 2.6 2.7 1.9 2.0 2.7 2.4 0.4 Absorbed, g/d 0.8 0.7 0.6 0.8 0.8 1.1 0.8 0.2 Urine, g/d 0.4 0.4 0.4 0.5» 0.4 b 0.6" 0.4 0.2 Retained, g/d 0.4 0.3 0.3 0.4 0.4 0.5 0.4 0.1 % of intake 12 9 8 13 13 12 11 4 % of absorded 52 44 45 45 44 43 46 12 mg/kg W075 20.1 14.6 13.9 16.4 16.3 22.5 17.2 6.7 Sodium Intake, g/d 4.6b " 3.7" 5.5»' 5.7* 5.3' 11.6» 6.1 2.7 Faeces, g/d 0.9 0.8 1.0 0.4 0.5 0.5 0.7 0.3 Absorbed, g/d 3.7" 2.9- 4.4» 5.3»' 4.8' 11.1» 5.4 2.8 Urine, g/d 1.8 1.0 2.5 3.4"' 3.2' 8.8" 3.5 2.6 Retained, g/d 1.9 1.9 1.9 1.9 1.6 2.4 1.9 0.4 % of intake 42 51 35 33» 30» 20" 35 10 % of absorded 52 66 43 43 33 21 43 16 mg/kg Wo7 ' 93.7 93.9 93.9 87.3 75.7 111.5 92.7 12.7 Potassium Intake, g/d 13.7"'' 11.3'f 15.4»' 18.3b 12.4» 32.8» 17.3 7.9 Faeces, g/d 3.9 4.8 3.8 3.3» 2.2" 3.6'» 3.6 1.2 Absorbed, g/d 9.7" 6.5b ' 11.6» 15.0b 10.2" 29.2» 13.7 7.9 Urine, g/d 6.4» 3.4b 9.0» 12.6' B.o' 25.6' 10.8 7.6 Retained, g/d 3.3 3.1 2.6 2.4 2.3 3.6 2.9 0.8 % of intake 24 27 17 13 19 11 19 7 % of absorded 34 47 23 16 23 12 26 13 mg/kg W 0 159 150 127 114 111 170 139 33 Iron Intake, mg/d 240b 247» 240b 196b 192" 204» 220 25 Faeces, mg/d 190 207 204 167 165 179 188 22 Absorbed, mg/d 51 40 35 29 27 25 34 14 Urine, mg/d 7 6 8 11 6 10 9 4 Retained, mg/d 44 34 27 18 21 15 27 14 % of intake 18 14 11 9 11 7 12 6 % of absorded 86 83 76 59 71 62 73 10 mg/kg W075 2.7 1.66 1.25 0.81 1.11 0.72 1.27 0.71 236 Protein supplements Sugar supplements Overall WPC CAS DSM HYLA SVC DW mean s.d. Copper Intake, mg/d 30.8' 31.3" 31.7» 27.9»< 24.4»' 28.9» 29.2 2.7 Faeces, mg/d 19.7 21.8 20.8 19.7 17.5 19.7 19.9 1.7 Absorbed, mg/d 11.1 9.5 10.8 8.3 6.9 9.3 9.3 1.8 Urine, mg/d 3.3 4.0 4.5 2.0" 0.6bc 3.3» 3.5 2.4 Retained, mg/d 7.8 5.5 6.3 6.2 6.4 6.0 6.4 2.1 % of intake 25 18 20 22 26 21 22 7 % of absorded 70 61 59 75 93 64 70 23 mg/kg W° 75 0.39 0.26 0.32 0.30 0.31 0.31 0.32 0.13 Zinc Intake, mg/d 202" 215» 211» 154b 154" 159» 182 31 Faeces, mg/d 129 139 120 95 89 111 114 23 Absorbed, mg/d 73 76 91 59 65 47 69 23 Urine, mg/d 3 3 3 6 3 4 4 1 Retained, mg/d 70 73 88 54 62 43 65 24 % of intake 35 34 41 35 40 27 35 9 % of absorded 96 96 97 91 94 91 94 3 mg/kg W° 7! 3.39 3.60 4.24 2.50 2.87 2.01 3.10 0.98 Manganese Intake, mg/d 59.2" 61.9» 58.2b 42.4 b 42.3 b 46.0» 51.7 9.1 Faeces, mg/d 53.7 56.8 54.9 39.4 36.6 44.1 47.9 8.2 Absorbed, mg/d 5.5 5.1 3.4 3.0 5.7 1.9 4.0 2.9 Urine, mg/d 000 000 00 Retained, mg/d 5.5 5.1 3.4 3.0 5.7 1.9 4.0 2.9 % of intake 9 12 6 7 13 4 8 4 % of absorded 100 100 100 100 100 100 100 0 mg/kg W075 0.27 0.35 0.16 0.13 0.26 0.09 0.20 0.11 Means with different letters were significantly different: a,b,c (P < 0.05); e,f,g (p < 0.01). Forsum, E. 1974, Nutritional evaluation of whey pro- tein concentrates and their fractions. J. Dairy Sci. 57: 665—, 1975 a. Whey proteins for food and feed supple- ment. Protein nutritional quality of foods and feeds. (Ed. M. Friedman). Part 2: 433—470. 1975 b. Effect of dietary lactose on nitrogen utiliza- tion of a whey protein concentrate and its corre- sponding amino acid mixture. Nutr. Rep. Internatl. 11 (5): 419—428. Fox, P.F. 1982. Developments in dairy chemistry. 1. Proteins. Appi. Sei. Pubi. London. Hankahan, T.J. 1971. Whey solids in the diet of growing-finishing pigs. I. Dried whey as a feed for pigs. Ir. J. Agric. Res. 10: I—7. Harju, M. 1984. Möjligheter att förbättra vasslens an- vändbarhet som fodermedel. Fodrets koncentrations- grad till svin ur foder- och avelssynpunkt. NJF Semi- narium Nr 57: 3: I—B. Henschel, M.J., Newport, M.J. & Williams, J.A. 1983. 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Ms received September 20, 1984 SELOSTUS Eri heravalmisteiden rehuarvosta ja fysiologisista vaikutuksista lihasialla Matti Näsi Helsingin yliopisto, Kotieläintieteen laitos, 00710 Helsinki Sulavuus- ja tasokokeissa tutkittiin ultrasuodatetun heravalkuaisrikasteen arvoa lihasian valkuaislähteenä vertaamalla sitä kaseiiniin ja rasvattomaan maitojau- heeseen ohrapohjaisella ruokinnalla. Samoin verrattiin entsymaattisesti hydrolysoitua laktoosisiirappia sakka- roosiin ja kuivattuun herajauheeseen (laktoosiin), kun niillä korvattiin 30 % ohrasta. Tutkimuksessa selvitet- tiin näiden lisäysten vaikutusta lihasian valkuais- ja ki- vennäisaineenvaihduntaan. Heravalkuaisrikasteen pro- teiinipitoisuus oli 42,2 % ja siinä oli runsaasti lysiiniä ja rikkipitoisia aminohappoja. Laktoosisiirapin hydrolyy- siaste oli 73 %. Heravalkuaisrikasteen proteiinin sula- vuus oli korkea, 99,1 Vo, kun taas herajauheen proteii- nin sulavuus jäi alhaiseksi, 72,5 %. Valkuaisen hyväksi- käyttö oli heravalkuaista sisältävällä dieetillä muita kor- keampi mitattuna typpitaseella ja urean erityksenä virt- sassa. Valkuaisen hyväksikäyttö oli niinikään heraval- kuaisrikastetta ja hydrolysoitua laktoosisiirappia sisäl- tävällä dieetillä tehokkaampaa kuin herajauhetta sisäl- tävällä dieetillä. Veriparametrien perusteella arvioituna suuret laktoosi- ja/taikivennäismäärät eivät olleet sioil- le haitallisia. Siat joivat vettä keskimäärin 49 % enem- män sokereita sisältävillä dieeteillä. Natriumin jakaliu- min ylimäärät erittyivät virtsassa, eikä sioilla esiintynyt ripulia suurien sokeri- ja/tai kivennäismäärien takia. 238