Sugar beet mash silage as a component of a total-mixed-ration for dairy cows--effects on parameters of digestion and animal performance.

Sugar beet mash silage (BMS) was offered in amounts up to 35% of DM to dairy cows as a component of a total-mixed-ration (TMR). Barley and molasses in the control ration were replaced by BMS half in ration BMS 1/2 and in total in ration BMS 1/1 on the basis of the calculated contents of net energy for lactation. Two trials were carried out. In trial I each ration was tested on parameters of rumen fermentation and digestibility of crude nutrients using 4 Holstein cows with rumen fistula. Chewing activity was tested on 2 Holstein cows for each ration. With the BMS rations the ruminal NH3 concentration was lower and the drop in pH was less than in the control ration. The pattern of volatile fatty acids in the rumen fluid from the BMS groups tended towards more propionic and butyric acid. The feeding of BMS showed no negative impact on chewing and rumination. Energy digestibility raised significantly from 59.8% in the control ration to 72.6% in the BMS 1/1 ration. In trial II the same rations were fed in a change-overdesign to a herd of 24 Holstein cows to test feed intake and animal performance. The results showed no significant effects of BMS rations on DM intake and milk production. The results of both trials indicate that even high amounts of cereals can be replaced by BMS without negative effects on rumen fermentation, milk yield and milk composition with slight drop in fat content. For a better handling of BMS, it is of advantage to include it in a TMR.     

Rumen fermentation and digestibility of nutrients studied by the addition of Ca soaps of palm oil fatty acids and their analogous fatty acids in the sheep model

The ruminally fistulated sheep was used as a model to study the effects of fat supplementation (Ca-soaps and free long chain fatty acids from palm oil) on rumen physiology and digestibility of the nutrients. The animals were fed with a typical ration of hay and concentrate supplying nutrients according to maintenance levels. The following results should be pointed out: The addition of free fatty acids and their Ca-soaps induced a retarded recovery of postprandially decreased pH-values in ruminal fluid. This retardation was more pronounced after addition of free long chain fatty acids than with their Ca-soap-analogous acids. Compared to the control, the concentration of short chain fatty acids was depressed by fat addition in the period 2 hours after feed intake. The release of ammonia in the first period after feed intake was reduced by fat addition. A lack of synchronity could be observed in this post-prandial period in ruminal fluid between concentration of short chain fatty acids and ammonia. This effect was most obvious with supplementation of unprotected fatty acids. This might be one reason for the better tolerance of Ca soaps from palm oil fatty acids. Formation of hydrides, branched chains and transforms proceeds more effectively with free fatty acids than with their analogous forms of Ca-soaps. The well-known effect of depression of digestibility of nutrients due to fat supplementation was--under present conditions--quite low. This might be different in lactating dairy cows with higher levels of feed intake. With high feed intake, passage time is reduced. This will affect digestibility and interactions with fat supplementation.     

The energy requirement of heifers. 4. Comparison of the digestibility and rumen physiologic parameters in heifers and full-grown sheep

In 159 comparative studies with fully grown sheep and heifers of the digestibility and of rumen physiologic values at a variation of the feed ration in the crude fibre content between 112 and 318 g, in the crude protein content between 94 and 194 g and in the content of nitrogen free extractive between 484 and 641 g/kg DM is provided that the digestibility of energy in heifers was, on average, 4 digestibility units lower than in sheep. The corresponding values for the digestibility of crude protein and crude fibre are 12 and 3.5 digestibility units. Due to the lower methane energy excretion of the heifers the difference at the level of metabolizable energy is reduced to 1.5% of the gross energy. The level of the differences in digestibility is influenced by the development of the young cattle and the composition of the rations. In young cattle of the live weight range between 100 and 150 kg the digestibility of the energy is 6-8 units lower than in sheep. A higher crude fibre content in the ration diminishes the difference in the digestibility of energy and the nutrients between the two animal species.     

The influence of various feedstuffs containing fat and protein on the digestibility of crude nutrients in young calves

Digestibility trials were carried out with calves, aged 3, 5, 7, 9, and 11 weeks, which were fed with feedstuffs of various energy and protein levels (various amounts of dried skim milk supplement with 146, 219, 323 g per day of the milk replacer Laktin) plus concentrate and hay. The purpose of the experiment was to find out what effect the amount of milk replacer varying daily had on the digestibility of the nutrients. The experiments confirm that the amount of milk replacer has a great influence on the digestibility of the crude fat. The amount of digestible crude fat consumed with the feed considerably influcenced the digestibility of the energy, it had little influence on the digestibility of the other nutrients, however. With increasing age the calves received more plant protein sources with a lower biologic value. Thus the digestibility of the protein in the complete ration was diminished as well. This shows that the digestibility was influenced by the protein quality, not, however, by the amount of crude protein. The digestibility of the dry matter andthe organic matter as well as of the N-free extractives in the feed ration diminished according to the changed composition with the increasing age of the animals; in constrast to this the digestibility of the crude fibres increased gradually.     

The effect of different high levels of soy extract pellets in the ration on the digestibility of crude nutrients, basic and sulfur-containing amino acids of wheat in colostomized laying hybrids

In two digestibility experiments with 4 colostomized laying hybrids each, the influence of 12.5% (ration 1) and 25% soybean meal (ration 2) on the digestibility of the crude nutrients, the basic and sulphur-containing amino acids in the wheat rations was tested. In ration 1 the digestibility of the crude protein was 84.9%, of the crude fat 56.6% and that of the N-free extractives 87.4%; for ration 2 the values were 83.6%, 47.4% and 82.5%. The digestibility values for wheat acquired with the difference method for ration 1 were 85.7% for crude protein, 57.0% for crude fat and 89.8% for N-free extractives; energy concentration was 766 EFUhens. For wheat supplemented with 25% soybean meal the same digestibility value of the crude protein could be ascertained, the digestibility of the crude fat and the N-free extractives, however, was lower than for ration 1 so that an energy concentration lower by 3.9% was calculated. The possible causes of the influence of the different levels of lysine and thioamino acids on the digestibility of these amino acids of wheat are described.     

饲粮添加包被蛋氨酸和包被叶酸对杜寒杂交二代公羔生长性能、养分消化代谢和瘤胃微生物蛋白质合成的影响

本试验旨在研究饲粮添加包被蛋氨酸（coated methionine,CM）和包被叶酸（coated folic acid,CFA）对杜寒杂交二代公羔生长性能、养分消化代谢及瘤胃微生物蛋白质合成的影响。采用2×2完全随机试验设计,试验因素为按照试验动物体重添加CFA（0 mg,CFA-或4 mg·（kg·d）^-1,CFA+）和CM（0 g,CM-或0.1 g·（kg·d）^-1,CM+）。将40只体重相近（（30.08±1.34）kg）的4月龄杜寒杂交二代公羔随机分为4组,分别饲喂基础日粮（CM-&CFA-）、基础日粮+CFA 4 mg·（kg·d）^-1（CM-&CFA+）、基础日粮+CM 0.1 g·（kg·d）^-1（CM+&CFA-）、基础日粮+CFA 4 mg·（kg·d）^-1+CM 0.1 g·（kg·d）^-1（CM+&CFA+）。试验期85 d,其中预试期15 d,正试期70 d,在试验期结束前10 d开展消化代谢试验。试验结果表明：1）饲粮添加CFA显著提高了1~30 d平均日增重和饲料转化率（P<0.05）,而添加CM仅显著提高了1~30 d饲料转化率（P=0.036）,对1~30 d平均日增重无显著影响（P>0.05）;饲粮中添加CFA、CM显著提高了杜寒杂交二代公羔31~60 d和1~60 d平均日增重及相应阶段饲料转化率（P<0.05）,二者对1~60 d饲料转化率具有显著互作效应（P=0.007）;2）饲粮添加CFA显著提高了干物质、有机物、中性洗涤纤维和酸性洗涤纤维的表观消化率（P<0.05）,饲粮添加CM有提高有机物表观消化率的趋势（P=0.066）及增加干物质消化率的趋势（P=0.095）,二者对养分消化率无显著互作效应（P>0.05）;3）饲粮添加CFA、CM显著降低了尿能排出量,显著提高了能量消化率和代谢率（P<0.05）;通过显著降低粪氮、尿氮及总排泄氮（P<0.05）,从而显著提高了氮的表观消化率和沉积氮水平（P<0.05）,且二者同时添加对减少氮排泄、提高氮消化率有显著互作效应（P<0.05）;4）饲粮添加CM、CFA显著提高嘌呤衍生物的尿排泄量,提高瘤胃微生物蛋白质合成量（P<0.05）。饲粮添加CM、CFA提高干物质和有机物表观消化率,改善总能消化率和代谢率,增加氮表观消化率和氮沉积量,促进杜寒杂交二代公羔的生长。     

Investigations concerning the use of the rumen fermentation regulator monensin in feeding fattening bulls

In two digestion experiments with wethers and seven feeding experiments with 198 fattening bulls with rations rich in (greater than 55% of the dry matter intake from roughage), the influence of the antibiotic monensin on the digestibility of the ration, on rumen-physiologic characteristic values and on fattening and slaughtering results was investigated. The digestibility of the organic matter and the crude nutrients was not significantly influenced by the use of monensin (20 mg/kg dry matter). The administration of 200 mg monensin per fattening bull and day resulted in an increase of the molar concentration of propionate in the rumen fluid by 9.7 mol%, the concentration of acetate and butyrate decreased by 7.3 resp. 2.8 mol %. On an average of the seven experiments the intake of dry matter was diminished by 5.1% through the use of monensin, the live weight increase remained almost unaffected (3.0% additional increase), feed and energy requirement per kg live weight were improved by 7.9%. The fattening results do not always correspond in the various experiments. The results of the dressing of the carcass, the composition of the carcass and the quality of the meat remained unaffected by the administration of monensin.     

Effect of flavomycin on the apparent digestibility of crude nutrients in wethers, parameters of rumen fermentation in cattle and feed intake and weight gain of heifers

Three experiments with five wether each were carried out in order to investigate the influence of various levels of flavomycin (0, 5 and 10 mg per animal and day) on apparent digestibility of artificially dried grass. A short time individual feeding experiment (42 days) with 9 bulls and a long term individual feeding experiment (225 days) with 52 heifers were conducted. Animals consumed 0 or 30 mg flavomycin per day. Parameters of rumen fermentation were investigated. Feed intake and weight gain were measured in the experiment with heifers. Flavomycin did not significantly influence the apparent digestibility of organic matter and crude nutrients as well as parameters of rumen fermentation. Flavomycin did not influence dry matter intake, but increased significantly weight gain (49 g per animal and day, 10.5%) and reduced feed and energy required per kg weight gain (10.6%) in heifers. The reasons of ergotropic effects of flavomycin are mostly unknown at present.     

Usage of feeding yeast "Fermosin" grown on mineral oil distillate in animal nutrition. 2. Digestibility of the nutrients of Fermosin feeding yeast on broilers (chickens) and fattening pigs]

The digestibility of the nutrients of Fermosin was tested on pigs and the following values were ascertained: organic matter=86%, crude protein=89% and N-free extractives=83%. The net energy ascertained on the basis of the content of nutrients and the digestibility of the nutrients of Fermosin amounts to 617 energetic feed units for pigs/kg dry matter. The true digestibility of the amino acids of Fermosin was determined on pigs and chicken. For lysin the true digestibility was ascertained as 95% (pigs) and 73% (Broilers). Due to the different digestion abilities of the two animal species, corresponding differences in the digestibility of the other amino acids were found as well.     

反刍动物日粮中非纤维性碳水化合物营养代谢的研究进展

非纤维性碳水化合物(NFC)是反刍动物日粮中重要的能量组成部分,其在日粮中的含量对反刍动物采食、生产性能、瘤胃发酵、营养物质消化和生理代谢等具有重要影响。本文就NFC对反刍动物采食量和生产性能、瘤胃代谢和营养素利用、机体健康和代谢等方面的影响进行综述,为进一步研究NFC及其科学应用提供参考依据。     

Nutritional values and antioxidative activities of whole peanuts and peanut skins for ruminant feeds

This study was conducted to investigate the nutritive values of two peanut by‐products, nonstandardized whole peanuts and peanut skins, along with their effects on microbial growth and fermentation in the rumen, their roughage values, and their antioxidative activities by a digestion trial using four goats. The experimental rations were alfalfa haycube (basal ration), 85% alfalfa with 15% whole peanuts, and 70% alfalfa with 15% whole peanuts and 15% peanut skins. The ether extracts and crude protein in whole peanuts were 47% and 27% on a dry matter basis (DM) both with over 90% of digestibilities, resulting in total digestive nutrients (TDN) of 140%. Peanut skins also had a high energy value with 91% of TDN. Ruminal concentrations of total volatile fatty acids (VFA) and acetic acid decreased in the rations containing the peanut by‐products, but the NDF digestibility and ruminal microbial protein estimated from urinary purines was not altered by feeding the peanut by‐products. Plasma oxidative stress maker, malondialdehyde, tended to be lower when peanut skins were supplemented. Whole peanuts and peanut skins could be used as high‐energy and high‐protein diets for ruminants, and peanut skins would be expected as a feed having antioxidant functions.     

Dependence of rumen fatty acid production on the composition of rations

In three experiments with two Black-and-White dairy cows the influence of soybean oil and coconut fat as well as that of rations rich in roughage and concentrated feed on the production of fatty acids were determined with the isotope dilution method. A change in the method of sampling from the rumen in the course of the investigations resulted in distinctly different absolute production quotas, which can presumably be traced back to the disproportionate mixing in of the isotope and/or different production quotas in various regions of the rumen. The relative differences between the production quotas dependent on the rations, however were approximately the same with both sampling methods, so that they make the comparison of the rations concerning rumen fermentation possible. The production of acetic acid and the total production of fatty acids (C2--C4) correlated closely both with the intake of digestible energy and the intake of digestible organic matter. There was also a highly significant correlation o that they make the comparison of the rations concerning rumen fermentation possible. The production of acetic acid and the total production of fatty acids (C2--C4) correlated closely both with the intake of digestible energy and the intake of digestible organic matter. There was also a highly significant correlation o that they make the comparison of the rations concerning rumen fermentation possible. The production of acetic acid and the total production of fatty acids (C2--C4) correlated closely both with the intake of digestible energy and the intake of digestible organic matter. There was also a highly significant correlation between the relation of acetic and propionic acid in the rumen fluid and the quotient from acetic and propionic acid produced. In contrast to this, a significant relation between the concentration of fatty acids and the production of fatty acids could not be ascertained. Soybean oil and coconut fat brought about a slightly better utilisation of the fat-free organic matter for the production of fatty acids in the rumen. This could mainly be traced back to the increased production of propionic acid. The production of acetic acid per kg fat-free organic matter was insignificantly reduced. A reduced quota of roughage in the ration as well as the use of feed fats resulted in a decrease in the production of acetic acid and an increase in the production of propionic acid. The influence of the quota of roughage, however, was bigger than that of the use of fats. When rations rich in roughage were given, the share the energy contained in the total fatty acids has in the total of the digested energy was, on an average of both animals, slightly lower in comparison to rations rich in concentrated feed. However, the reason for this is not to be found in a lower share the energy digested in the stomachs has in the total of digested energy but in a higher amount of fermentation losses with a nutrition rich in roughage.     

The effect of copper and cobalt supplementation on the digestibility of fibrous feed in sheep]

The effects of an addition of copper, cobalt, and copper + cobalt on the in vitro digestibility of hay, treated beech sawdust and cellulose by the rumen fluid of sheep fed a complete food ration, complete food ration with 15% treated beech sawdust and a diet consisting of 80% hay and 20% barley were investigated, respectively. The rumen fluid obtained from animals fed a complete food ration showed the significantly higher digestibility of hay (Tab. I) when Cu (P less than 0.05), Co, or Cu + Co (P less than 0.001) had been added into the rumen. The cellulose digestibility increased only after Co application (P less than 0.05). The microelements supplementation in all three forms had a very significant effect on the digestibility of treated beech sawdust by the rumen fluid of sheep fed a diet with 15% sawdust content, although the initial digestibility by the rumen fluid in the control animals (without microelements) was only 44.9%. A similar trend was also observed in the cellulose digestibility, but after Co application this increase was not significant. The rumen fluid of animals fed hay (80%) and barley (20%) showed the highest digestibility. The digestibility of sawdust reached 60% and the of cellulose 95.9% without microelements supplementation (control). In this case the effect of microelement supplementation on the sawdust digestibility was manifested only in the case of cobalt by the digestibility decrease (P less than 0.001). The cellulose digestibility also decreased after administration of Cu (P less than 0.01) and Co (P less than 0.05). The Cu + Co supplementation did not influence its digestibility.(ABSTRACT TRUNCATED AT 250 WORDS)     

The dynamics of the content of ammonia and volatile fatty acids in the rumen fluid during the use of dry feed rations in the cow

The development of the pH-value, the molar quota of volatile fatty acids and of the NH3 content in the change from silage rations to dried rations on the basis of pelleted feed and in dependence on the time after the beginning of feeding was tested in studies of the rumen fluid of four cows in order to explain the causes of the very low NH3 content of the rumen fluid in feeding experiments with rations based on pelleted straw-concentrate mixtures. An influence of the ration type and the time after the beginning of feeding on the molar quota of the individual volatile fatty acids and the NH3 content was ascertained. The ration type tested can cause an NH3 content in the rumen fluid below 1 mmol/l.     

The effect of avoparcin on apparent digestibility, characteristics of rumen fermentation and fattening and slaughter output of growing cattle

Four digestion experiments with 5 wethers each (0, 15, 30 or 60 mg avoparcin per animal and day), three individual feeding experiments (28, 18 or 56 bulls per experiment; 0 and 150/200; 0, 250 and 500 or 0 and 200 mg avoparcin per animal and day in the experiments 1, 2 or 3) and two group feeding experiments (60 bulls and 161 heifers per experiment; salt lick stones without or with 2.5 g avoparcin per kg) were carried out in order to investigate the influence of avoparcin on apparent digestibility, figures of rumen fermentation, fattening and slaughtering results as well as protein, fat and energy retention. Avoparcin supplementation did not significantly influence the apparent digestibility of organic matter and crude nutrients. Concentration of acetate of rumen liquid was decreased (16 or 36) and that of propionate was increased (25 or 50 mmoles per mol) when 200 or 500 mg avoparcin per animal and day were added. Acetate:propionate ratio decreased from 4.2 to 3.5 and 3.1:1. Avoparcin did not influence feed intake, enhanced daily weight gain (37 to 174 g per animal and day) and improved feed efficiency (5 to 26%). Salt lick stones with avoparcin increased weight gain (58 and 96 g per animal and day). Slaughtering results and body composition of bulls were not influenced by avoparcin. Daily retention of protein, fat and energy was significantly increased (16 to 18%; P less than 0.05) when avoparcin was supplemented.     

Feeding value of total mixed ration silage with spent mushroom substrate

Six wethers were used in a digestibility experiment arranged as replicated 3 × 3 Latin square to evaluate the nutritive value of total mixed ration (TMR) silages that were made from ensiling of TMR containing 0, 6.5 and 13.0% (dry matter basis) of spent mushroom substrate (SMS) for 45 days (treatments denoted as CSMS, LSMS and HSMS, respectively). The amount of SMS replaced the same amount of timothy hay in the respective TMR. All TMR were well preserved as indicated by their low pH, low ammonia‐N and high lactic acid contents. Increasing levels of SMS in the TMR silage quadratically reduced (P < 0.05) nutrient digestibility with the exception of ether extract. The difference of total digestible nutrients and digestible energy contents between LSMS and CSMS TMR silage were less than those between LSMS and HSMS. Increasing concentration of SMS in the ration tended to decrease content of total volatile fatty acids in rumen fluid but increased the ratio of acetate to propionate and pH. The study suggests that a SMS level of 6.5% in the diet DM can be recommended for silage based TMR.     

甘蔗品种及收割期对生长期肉牛采食量和瘤胃参数的影响

本试验旨在研究甘蔗青贮饲料的基因型和成熟期对肉牛瘤胃纤维消化率、采食量、瘤胃发酵、瘤胃动力学和瘤胃细菌数量的影响。试验采用2×2因子设计,即两个基因型(高和低中性洗涤纤维消化率)和2个收割期(早熟和晚熟)。试验日粮以40%青贮甘蔗饲料为试验料。结果:饲喂早熟甘蔗青贮饲料时干物质采食量较大,但仅表现在低中性洗涤纤维消化率基因型(P<0.05)。早熟甘蔗日粮较晚熟甘蔗日粮显著提高了中性洗涤纤维摄入量(P<0.05)。饲喂低中性洗涤纤维基因型饲粮时,瘤胃池干物质、中性洗涤纤维和不可消化中性洗涤纤维含量更高(P<0.05)。饲喂高中性洗涤纤维消化率品种的青贮甘蔗时,中性洗涤纤维和不可消化中性洗涤纤维过瘤胃速率更高(P<0.05)。饲喂早熟青贮甘蔗饲料的肉牛瘤胃pH较大,但表现在高中性洗涤纤维消化率品种组(P<0.05)。饲喂早熟青贮甘蔗饲料时,低中性洗涤纤维消化率品种组肉牛瘤胃短链脂肪酸总浓度较高(P<0.05)。晚熟期青贮甘蔗较早熟期显著提高了埃氏巨球型菌相对含量(P<0.05)。综上所述,采用高中性洗涤纤维消化率品种的青贮甘蔗饲喂生长期肉牛,可以通过更快的纤维过瘤胃速率和纤维周转对瘤胃池产生积极影响,这可能有利于提高采食量。     

Effects of the natural sweetener rebaudioside A on intake,nutrient digestion,rumen fermentation,and blood biochemical parameters in adult goats during summer

The effects of dietary rebaudioside A inclusion on feed intake, digestion of nutrients, rumen fermentation, and blood biochemical parameters of goats were evaluated in a replicated 3 × 3 Latin square study. Nine adult goats during summer were fed a basal forage/concentrate-based diet and the forage was chopped rice straw. The three dietary treatments were 0, 350, and 700 mg rebaudioside A per kg chopped rice straw on a DM basis. No significant improvement was observed in dry matter intake (DMI) of forage and diet among treatments. Nutrient digestibility of DM and organic matter (OM) showed a significant trend (p < .10) across groups. Rebaudioside A inclusion significantly (p < .01) increased the concentration of total volatile fatty acids in the rumen, however, there were no differences in concentration of ruminal ammonia, and molar proportions of acetate, propionate, and butyrate. About blood metabolites, increasing rebaudioside A in the diet caused a quadratic response in glucose and total protein, and albumin concentrations. Under the conditions of this study, supplementation with rebaudioside A at 350 and 700 mg/kg forage did not improve consumption of rice straw-based diet in adult goats in summer. However, the responses in digestibility, rumen fermentation, and blood metabolites appear to indicate the potential of rebaudioside A as a bio-active substance in goats.     

Feeding different dietary protein to energy ratios to Holstein heifers: effects on growth performance,blood metabolites and rumen fermentation parameters

Eighteen Chinese Holstein heifers average age 230 ± 14 days were allocated to 1 of 3 dietary crude protein (CP) to metabolizable energy (ME) ratios to examine the effects on growth performance, blood metabolites and rumen fermentation parameters with 90‐days experiment. Three different dietary CP:ME ratios were targeted based on the formulation of dietary CP contents of 10.85%, 12.78% and 14.63% on dry matter (DM) basis with similar ME contents (10.42 MJ/kg DM), which were categorized as low, medium and high dietary CP:ME ratios. The actual CP:ME ratios obtained in this study significantly increased from low to high CP:ME ratio groups with a value of 10.59, 11.83 and 13.38 g/MJ respectively. Elevated CP:ME ratios significantly increased CP intake (kg/day) and feed efficiency (FE) which was defined as dry matter intake as a proportion of average daily gain (ADG), whereas little difference was observed in body weight (kg), ADG (kg/day), DM intake (kg/day) and ME intake (MJ/day) among the three different CP:ME ratio groups. Increasing dietary CP to ME ratios significantly increased CP digestibility, whereas digestibility of DM and gross energy remained constant in the current experiment. Blood urea nitrogen and insulin‐like growth factor‐1 linearly increased with increasing dietary CP:ME ratios. There was significantly dietary treatment effect on rumen fermentation parameters including acetate, propionate, butyrate and total volatile fatty acids. Therefore, this study indicated that increasing dietary CP levels with similar energy content contributed to increased protein intake and its digestibility, as well as FE. Holstein heifers between 200 and 341 kg subjected to 13.38 dietary CP:ME ratio showed improved feed efficiency, nutrient digestibility, some blood metabolites and rumen fermentation characteristics for 0.90 kg/day rate of gain.     

The effect of different levels of soybean extract meal on the apparent digestibility of crude nutrients and amino acids in colostomized laying hens

Four colostomized laying hens per group were given a ration of barley and soya bean oil meal (SBM) with 12.5, 25.0 and 37.5% SBM resp. The crude protein intakes were 14.0, 17.7 and 21.4 g per animal and day. The lysine intake raised from 681 mg (group 1) to 1275 mg (group 3) per animal and day. The digestibility of dry matter and of the N-free extracts of the ration decreased with the rising SBM portion in the ration. The digestibility of crude protein remained constant. The investigated amino acids (Lys, His, Arg, Cys, Met) were higher digested in the 37.5% SBM ration than in the 12.5% SBM ration. The following digestibility values for SBM were found by means of the difference method: Dry matter 52.5%, crude protein 83.1%, crude fat 51.7%, crude fibre 5.5%, N-free extracts 50.6%. The level of the SBM did not influence the digestibility of the crude nutrients. The apparent digestibility of lysine from SBM depended on the level of intake and was found to be 82.3, 83.4 and 89.0%, resp. There were no differences in the digestibility of other amino acids.