Determination of apparent ileal amino acid digestibility in rapeseed meal and cake processed at different temperatures using the direct and difference method with growing pigs.

Studies were conducted with ten barrows, average initial body weight 34.5 +/- 2.1 kg, fitted with a T-cannula at the distal ileum, to study the accuracy of determination of the apparent ileal digestibility (AID) values of crude protein (CP) and amino acids (AA) in rapeseed meal and cake and the effects of processing, using the difference method. Five corn starch-based diets in the studies were formulated to contain 17.7% CP and based on soybean meal, prepress-extraction rapeseed meal, prepress-extraction rapeseed meal plus soybean meal, high-temperature press rapeseed cake plus soybean meal, or low-temperature press rapeseed cake plus soybean meal as the sole source of dietary protein. The design was an incomplete Latin Square involving two three-week periods and five-treatments. It was found that the AID values of CP and most AA determined with the difference or direct method were significantly lower in rapeseed meal or cakes than soybean meal. The AID values of CP and most AA in prepress-extraction rapeseed meal, high-temperature press or low-temperature cakes determined with the difference method were no difference from those in prepress-extraction rapeseed meal determined with the direct method. The AID values of CP and AA in rapeseed meal and cake determined with the difference method were accurate, when the contribution of CP and AA from rapeseed was more than 50%. The AID values of CP and AA (especially lysine) were lower in the high-temperature press rapeseed cake than in the low-temperature press cake or the prepress-extraction meal.     

日粮中紫苏饼、菜籽粕代替豆粕对肉牛养分表观消化率及氮代谢的影响

试验旨在研究日粮中紫苏饼、菜籽粕代替豆粕对肉牛养分表观消化率及氮代谢的影响。选择20头体重相近、健康状况良好的12月龄左右的秦川肉牛（母牛）为试验动物,按照单因素随机区组设计,将20头试验牛分为5组,每组4头牛。不同试验组日粮中分别添加以31%豆粕（对照）、36%菜籽粕、14%紫苏饼+24%菜籽粕、28%紫苏饼+12%菜籽粕和42%紫苏饼为蛋白质原料配制的5种不同的精饲料。试验持续120 d,其中预饲期15 d,正试期105 d。试验期间,测定每头试验牛每天的摄入氮、尿氮及粪氮,测定日粮中干物质（DM）、有机物（OM）、中性洗涤纤维（NDF）和酸性洗涤纤维（ADF）的表观消化率。结果表明：① 42%紫苏饼组摄入氮含量最高,36%菜籽粕组最低,但各组间氮含量差异不显著（P>0.05）;36%菜籽粕组的粪氮显著高于28%和42%紫苏饼组（P<0.05）,且与31%豆粕组和14%紫苏饼组差异不显著（P>0.05）;② 42%紫苏饼组的沉积氮最高,与其他各组均差异显著（P<0.05）,其中31%豆粕组显著高于36%菜籽粕组（P<0.05）;③ 42%紫苏饼组的DM、ADF表观消化率显著高于31%豆粕组和36%菜籽粕组（P<0.05）,14%和28%紫苏饼组的DM、OM和NDF的表观消化率均差异不显著（P>0.05）;④ 14%紫苏饼组尿液中尿素氮含量显著高于31%豆粕组和42%紫苏饼组（P<0.05）,且与36%菜籽粕组和28%紫苏饼组差异不显著（P>0.05）;31%豆粕组尿液中马尿酸氮含量显著高于36%菜籽粕组和42%紫苏饼组（P<0.05）,而这3组均显著高于14%和28%紫苏饼组（P<0.05）;31%豆粕组的尿囊素氮含量显著高于42%紫苏饼组（P<0.05）,与其他3组差异不显著（P>0.05）;各组的肌酸氮、微生物氮预测值、尿素氮/尿氮、肌酸氮/尿氮和嘌呤衍生物氮/尿氮均没有显著差异（P>0.05）。综上,本试验条件下,精料中用42%紫苏饼代替31%豆粕,肉牛氮沉积最高,比对照组高3.65 g/d;DM、OM、NDF、ADF的表观消化率分别比对照组高3.45%、2.22%、6.56%、10.98%。     

Effects of Perilla Cake and Rapeseed Meal Instead of Soybean Meal in Diet on Apparent Digestibility and Nitrogen Metabolism of Beef Cattle

The purpose of this experiment was to study the effect of perilla cake and rapeseed meal instead of soybean meal on the apparent digestibility and nitrogen metabolism of beef cattle.20 Qinchuan beef cattle of about 12 months old with similar weight and good health were selected and divided into 5 groups with 4 cattle in each group according to the univariate randomized block design.Five different protein feeds treatments were 31% soybean meal,36% rapeseed meal,14% perilla cake+24% rapeseed meal,28% perilla cake+12% rapeseed meal and 42% perilla cake,respectively.The experiment lasted 120 days,of which the pre-feeding period was 15 days and the trial period was 105 days.During the test,the daily intake of nitrogen,urine nitrogen and fecal nitrogen,the apparent digestibilities of dry matter (DM),organic matter (OM),neutral detergent fiber (NDF) and acid detergent fiber (ADF) of each test cow were determined.The results showed that:① The 42% perilla cake group had the highest nitrogen intake,and the 36% rapeseed meal group had the lowest nitrogen content,and the differences between the groups were not significant (P>0.05).The manure nitrogen in 36% rapeseed meal group was significantly higher than 28% and 42% perilla cake groups (P<0.05),and there was no significant difference with 31% soybean meal group and 14% perilla cake group (P>0.05).② The 42% perilla cake group had the highest sedimentary nitrogen,which was significantly different from other groups (P<0.05),and the 31% soybean meal group was significantly higher than 36% rapeseed meal group (P<0.05).③ The apparent digestibility of DM and ADF in 42% perilla cake group were significantly higher than those in 31% soybean meal group and 36% rapeseed meal group (P<0.05).There was no significant difference in apparent digestibility of DM,OM and NDF between 14% and 28% perilla cake groups (P>0.05).④ The content of urea nitrogen in 14% perilla cake group was significantly higher than 31% soybean meal group and 42% perilla cake group (P<0.05),and it was not significantly different from the 36% rapeseed meal group and 28% perilla cake group (P>0.05).The 31% soybean meal group had significantly higher nitrosate nitrogen content than 36% rapeseed meal group and 42% perilla cake group (P<0.05),and these three groups were significantly higher than 14% and 28% perilla cake groups (P<0.05).Allantoin nitrogen in 31% soybean meal group was significantly higher than 42% perilla cake group (P<0.05),and there was no significant difference from the other three groups (P>0.05).There was no significant differences in creatine nitrogen,microbial nitrogen predicted value,urea nitrogen/urine nitrogen,creatine nitrogen/urine nitrogen,and purine derivative nitrogen/urine nitrogen among all groups (P>0.05).In summary,in this test,when 42% perilla cake was used instead of 31% soybean meal in the concentrate,the beef cattle had the highest nitrogen deposition,which was 3.65 g/d higher than 31% soybean meal group.The apparent digestibility of DM,OM,NDF and ADF were 3.45%,2.22%,6.56%,and 10.98% higher than 31% soybean meal group,respectively.     

Profile of digested feed amino acids from untreated and expander treated feeds estimated using in situ methods in dairy cows

Guar meal, sunflower meal, rapeseed cake, peas, maize, rye, wheat and barley were subjected to expander treatment at different temperatures (95–150 °C), and effect on amino acid availability was assessed using rumen nylon bag and mobile bagin situ methods. Expander treatment of rapeseed cake at 142 °C decreased feed lysine content, probably due to formation of complex compounds. Effective rumen degradability and total tract digestibility of protein, total amino acids, lysine, methionine, threonine, isoleucine, leucine, valine, and phenylalanine were compared to values for the untreated feeds. Effective rumen degradability seemed to decrease due to expander treatment for all cereals, except maize. Effective rumen degradability for sunflower meal and rapeseed cake was unaffected by expander treatment at 115 °C, whereas expander treatment at 142 °C appeared to decreased effective rumen degradability for rapeseed meal. Total amino acid digestibility was not decreased by expander treatment. Both for untreated and heat treated feeds rumen degradability and total tract digestibility of individual amino acids were generally in agreement with results for crude protein. Observed amino acid profiles supplied by digestible rumen undegraded feed amino acids were compared to a theoretical optimal profile obtained from the literature using a χ²-index. A low index is equivalent to a high biological value. Smallest and largest index for the difference between the observed and theoretical optimal amino acid profile were obtained for peas and maize, respectively. Lysine was the first limiting amino acid for cereals, sunflower meal, expander treated (142 °C) rapeseed cake and untreated guar meal, leucine for untreated and expander treated (115 °C) rapeseed cake, and methionine for peas and expander treated guar meal. It was concluded that based on the assumed ideal amino acid profile, expander treatment only changed the first limiting amino acid for rapeseed cake and guar meal, and that although expander treatment decreased the index, and thereby improved the biological value of the intestinally digested feed amino acids, the ranking of feeds based on the index was unaffected by expander treatment.     

Evaluation of rapeseed meal with low and high glucosinolates as a protein source in calf starters

Inclusion of 20% rapeseed meal in calf starters for rearing male calves in substitution for soybean meal significantly (P < 0.05) decreased the organic matter digestibility as determined with sheep. Calf starter with 10% rapeseed meal had an intermediate, but not significantly different digestibility.Feeding calf starters with 0, 10 or 20% rapeseed meal to rearing calves did not result in a significantly different average daily gain. Growth rate during 20 weeks averaged 0.80, 0.76 and 0.77 kg per day, respectively. When glucosinolate content is considered, the use of high glucosinolate rapeseed meal provoked a lower but not significantly different daily gain in comparison with soybean meal as supplemental protein source. Substitution of soybean meal with rapeseed meal decreased total starter intake from 270.4 to 262.1 and 259.6 kg and increased hay intake from 53.7 to 55.1 and 62.7 kg. However differences were not significant (P > 0.05). Feed conversion was similar and amounted to 2.94, 3.00 and 2.98 kVEM. The utilization of 20% rapeseed meal with high glucosinolate content significantly (P < 0.05) reduced starter intake.The incorporation of rapeseed meal reduced the palatability of the calf starter. When 20% rapeseed meal was included the rate of intake was significantly lower during the 8th and 14th experimental weeks. The mean rates of intake for a calf starter containing 20% rapeseed meal with either a high or a low glucosinolate level were 76.6 and 83.7% of the rate obtained for the calf starter without rapeseed meal.     

Selecting soybean meal characteristics preferred for swine nutrition

As environmental constraints become more important issues for the animal industry, selecting feed ingredients that yield good animal performance but also minimize environmental impact of animal production becomes critical. The objective of this research was to identify which compositional features would be desirable for soybean meal to maximize nutritional value and minimize animal waste. Eight soybean samples were selected from a database of 72, such that maximal variability for CP, NDF, and ADF content was obtained. Samples were subsequently processed into meal using standardized procedures. In Experiment 1, 8 cannulated pigs were used to determine ileal digestibility following a Latin square design. In Experiment 2, 5 of the samples were used in complete feeds and 10 pigs were used in a crossover Latin square design to determine the total tract digestibility, odorants in fresh and 5-d-old manure, and ammonia emission from manure. Differences up to 6% in ileal DM digestibility and 8% in ileal CP digestibility were observed. This difference was reduced to 1.1% for total tract DM digestibility and 4% for total tract CP digestibility. Differences in odorant concentration were 3-fold and for in vitro ammonia emission were 42%. The only compositional variable with a significant effect on digestibility was stachyose, which negatively affected ileal digestibility of DM (r = -0.80, P = 0.02) and energy (r = -0.73, P = 0.04). None of the compositional variables measured affected ileal CP digestibility. Ileal CP digestibility, however, was correlated with estimated CP fermentation in the large intestine (r = -0.86, P = 0.06) and with in vitro ammonia emission after 48 h (r = -0.81, P = 0.09). In conclusion, nutritionally relevant variability exists in soy varieties. Low stachyose content is important for maximizing ileal energy digestibility of soybean meal. Although no compositional variable was identified that explained differences in ileal CP digestibility, maximizing ileal CP digestibility is of interest for maximizing the nutritional value of soybean meal and possibly for reducing ammonia and odor emissions.     

Effect of soybean meal particle size on amino acid and energy digestibility in grower-finisher swine

A study was conducted using the ileal digestibility technique with grower-finisher pigs to evaluate the effects of particle size reduction of soybean meal (SBM) on amino acid and energy digestibility. Soybean meal was processed through a hammer mill to achieve average particle sizes of 900, 600, 300, and 150 microm. The treatments included the use of two soybean meal sources and soy protein concentrate. One source of SBM was ground to four different particle sizes (i.e., 949, 600, 389, 185); a second source was a common SBM source used in other trials (i.e., 800 microm). The soy protein concentrate had an average particle size of 385 microm. A low-protein (5% casein) diet was fed to determine endogenous amino acid losses. This experiment was conducted in a 7 x 7 Latin Square design in two replicates using 14 crossbred barrows ([Landrace x Yorkshire] x Duroc) that averaged 28 kg BW and 60 d of age. Animals were surgically fitted with a T-cannula at the distal ileum. Treatment diets were fed in meal form, initially at 0.09 kg BW(0.75) and at graded increases at each subsequent period. Pigs within replicate were fed a constant quantity of their treatment diet for a 5-d adjustment period followed by a 2-d collection of ileal digesta samples. Apparent and true digestibility of amino acids was calculated by use of chromic oxide (0.5%) as an indigestible marker. Apparent digestibility of isoleucine, methionine, phenylalanine, and valine increased linearly (P < 0.05) as particle size decreased. True digestibility of isoleucine, methionine, phenylalanine, and valine increased linearly (P < 0.05) as particle size decreased. When the essential amino acids were averaged, apparent digestibility increased (P < 0.10) from 83.5% to 84.9% as particle size decreased, whereas, nonessential amino acid digestibility increased only slightly (P > 0.15). Essential amino acid true digestibility increased numerically from 91.0% to 92.4% as particle size decreased. Energy digestibility was not affected by particle size (P > 0.15). These results suggest that a reduction in particle size of soybean meal resulted in a small increase in the digestibility of its amino acids with the essential amino acids being affected more than the nonessential amino acids. The largest improvement in digestibility, however, was obtained when the particle size was reduced to 600 microm.     

Nutritional value of quality protein maize for starter and finisher swine.

Growth trials with starter (n = 120, 6.8 kg initially, 28 d of age, Exp. 1) and finisher (n = 70, 59 kg initially, Exp. 2) pigs were conducted to compare quality protein maize (QPM, .40% lysine) and normal corn (.31% lysine) in simple corn-based diets containing the same levels of soybean meal. In Exp. 1, pig performance was similar (P greater than .10) on all diets, regardless of the level of soybean meal, suggesting that QPM and normal corn have similar feeding value in lysine-adequate (.99 to 1.11%) diets. In Exp. 2, less soybean meal was needed in QPM than in normal corn diets to maximize performance; increasing soybean meal from 10.8 to 13.8% improved rate (P less than .05) and efficiency (P less than .01) of gain of pigs fed normal corn diets but had no effect on performance of pigs fed QPM diets. A QPM-based diet containing 6% soybean meal and supplemental lysine and tryptophan failed to maximize feed efficiency, but growth rate was equal to that obtained on the normal corn diet with 13.8% soybean meal. The apparent fecal digestibility of GE and ileal digestibility of N were similar for QPM and normal corn, but apparent ileal digestibility of most essential amino acids was slightly higher for QPM (Exp. 3). Experiment 4 compared apparent digestibilities of QPM, conventional opaque-2 corn and two high-protein corns. Digestibilities differed (P less than .05) among the corns, but the absolute differences were small and were likely due to differences in amino acid content of the corns.(ABSTRACT TRUNCATED AT 250 WORDS)     

Amino acid profile of escaped feed protein after rumen incubation and their intestinal digestibility.

The crude protein content and amino acid profile of seven feedstuffs (linseed meal, maize gluten meal, rapeseed meal, rapeseed meal protected, soybean meal, fullfat soybean extruded and sunflower meal) were determined before and after ruminal incubation for 16 h in three bulls with large rumen cannulas. The intestinal disappearance of amino acids was measured using mobile bag technique. Ruminal incubation affected amino acid profile of all experimental feedstuffs. Crude protein degradation varied from 29.3% for maize gluten meal to 86.4% for rapeseed meal. A tendency towards increased disappearance was observed for glutamic acid, histidine, lysine and proline and decreased disappearance for branched-chain amino acids. The intestinal crude protein digestibility was higher than > 80%, except rapeseed meal (66.4%) and sunflower meal (77.8%). The least digestible individual amino acids were methionine and isoleucine in rapeseed meal, histidine and methionine in rapeseed meal protected and arginine in sunflower meal. In general, the lowest amino acid digestibilities were found in feedstuffs with the highest fibre content. The feedstuffs show that they have different potential for supplying of limiting amino acids. Of particular value are the feedstuffs with low crude protein degradability in the rumen and high intestinal digestibility of amino acids.     

Digestion of soybean meal and canola meal protein and amino acids in the digestive tract of young ruminants

Eight male Holstein calves (body weight 68 +/- 5 kg; age 75 +/- 6 d), each with a permanent re-entrant pancreatic cannula and T-type ileal and duodenal cannulas, were used in a crossover design with four animals per group to determine amino acid kinetics and digestibilities in the digestive tract of calves fed soybean meal (SBM) and canola meal (CM) protein. The SBM and CM diets were fed twice daily at a level of 900 g at each feeding time (air-dry basis). With the exception of methionine, crude protein and amino acid flows at the proximal duodenum, expressed as a percentage of intake, were not influenced by dietary protein source. Apparent ileal and total tract digestibilities of CP and amino acids were reduced (P less than .05) by feeding CM compared to SBM, but apparent ileal digestibility of methionine was not affected by dietary protein source. Except for methionine, net disappearance of all amino acids in the small intestine, relative to the amount fed, was higher for the SBM diet than for the CM diet. Net disappearance or synthesis of amino acids in the large intestine were not affected by dietary protein source. Similarly, dietary protein source did not affect (P greater than .05) the secretion of pancreatic juice or concentrations of protein, chymotrypsin and trypsin in pancreatic juice. Soybean meal protein has higher ileal and total gastrointestinal tract digestibility than CM protein for young, growing calves.     

Processing conditions affect nutrient digestibility of cold-pressed canola cake for grower pigs

Cold-pressed canola cake is a coproduct of biodiesel production that contains more residual oil than expeller-pressed and solvent-extracted canola meal. Cold-pressed canola cake might be an attractive feedstuff for swine due to local availability from small plants. However, the nutritional quality and content of anti-nutritional factors of cold-pressed canola cake are poorly defined and vary with processing conditions. This experiment evaluated cold-pressed canola cake processed using 4 different conditions: a nonheated and heated barrel at slow and fast screw speed in a 2 × 2 factorial arrangement. Seven ileally cannulated barrows (26 kg of BW) were fed twice daily at 2.8 × maintenance diets containing either 44% of 1 of the 4 cold-pressed canola cake samples, expeller-pressed canola meal, canola seed, or an N-free diet in a 7 × 7 Latin square. The objectives were to measure the energy and AA digestibility and to calculate standardized ileal digestible (SID) AA and NE content. Each 9-d experimental period consisted of a 5-d diet adaptation, followed by 2-d feces and 2-d ileal digesta collections, and 7 observations per diet were obtained. Cold-pressed canola cake contained 41% CP, 16% ether extract, and 5 μmol of total glucosinolates/g (DM basis). Both apparent ileal digestibility (AID) and total tract energy digestibility of energy in cold-pressed canola cake was 36% greater (P < 0.05) in heated vs. nonheated conditions and 8% greater (P < 0.05) in fast vs. slow screw speed without interaction, indicating that heat enhanced energy digestibility. The AID of energy of cold-pressed canola cake was 13 and 118% greater (P < 0.01) than expeller-pressed canola meal and canola seed, respectively. Heat and speed interacted (P < 0.05) for SID of AA of test ingredients, but effects were not consistent among AA. The DE and calculated NE content of cold-pressed canola cake was 0.73 and 0.52 Mcal/kg greater (P=0.001; DM basis), respectively, than expeller-pressed canola meal and did not differ from canola seed. Cold-pressed canola cake averaged 4.17 Mcal of DE/kg, 2.84 Mcal of NE/kg, 0.87% SID Lys, 0.46% SID Met, and 0.79% SID Thr (DM basis). In conclusion, processing conditions greatly affected the digestible nutrient content of cold-pressed canola cake. Content of residual ether extract was an important determinant of the energy value of cold-press canola cake, whereas residual glucosinolates did not seem to hamper nutrient digestibility.     

肉牛常见饲料干物质和蛋白质瘤胃降解特性和小肠消化率研究

[方法]选用装有瘤胃瘘管和小肠瘘管的肉牛作为试验动物,尼龙袋法测定肉牛常见饲料干物质(DM)和粗蛋白(CP)的瘤胃降解特性和小肠消化率。[结果]结果表明,DM瘤胃有效降解率由高到低为玉米粉、麦麸、苜蓿干草、豆粕、菜籽粕、玉米青贮、醋糟、白酒糟;CP瘤胃有效降解率由高到低为苜蓿干草、麦麸、豆粕、醋糟、玉米粉、玉米青贮、菜籽粕、白酒糟;DM小肠消化率由高到低为豆粕、菜籽粕、玉米粉、白酒糟、醋糟、麦麸、苜蓿干草、玉米青贮;CP小肠消化率由高到低为豆粕、菜籽粕、玉米粉、苜蓿干草、麦麸、白酒糟、玉米青贮、醋糟。[结论]试验表明,不同饲料瘤胃降解特性不同,为小肠提供过瘤胃可消化蛋白的能力不同,且饲料的DM小肠消化率小于CP小肠消化率。     

不同方法测定瘤胃非降解蛋白质小肠消化率及相关性分析

本试验分别采用移动尼龙袋法、改进三步体外法、原始三步体外法和酸性洗涤不溶氮(ADIN)估测法测定13种精料的瘤胃非降解蛋白质(RUP)小肠消化率,并对移动尼龙袋法与其他方法的测定结果进行相关性分析,同时对常规营养成分和RUP小肠消化率作回归分析,旨在寻找替代移动尼龙袋法测定RUP小肠消化率更简单快速的方法.试验采用单因素试验设计,选取3头装有永久瘤胃瘘管和十二指肠T型瘘管的奶牛.结果表明:移动尼龙袋法测得的豆粕、棉籽粕、菜籽粕、葵花粕、芝麻粕、玉米胚芽粕、玉米、米糠、米糠粕、米糠饼、大麦、麦麸和玉米麸质饲料的RUP小肠消化率分别为98.13％、87.37％、88.47％、82.60％、85.73％、75.40％、93.23％、69.27％、77.83％、92.10％、91.27％、72.37％和79.03％.改进三步体外法测定结果与移动尼龙袋法测定结果的相关系数为0.8383;原始三步体外法测定结果与移动尼龙袋法测定结果的相关系数为0.7899;ADIN估测法预测结果与移动尼龙袋法测定结果无显著相关(P＞0.05);饲料RUP小肠消化率与饲料常规营养成分含量显著相关(P＜0.05).改进三步体外法比原始三步体外法替代移动尼龙袋法测定饲料RUP小肠消化率效果更好.应用体外法替代移动尼龙袋法测定蛋白质饲料RUP小肠消化率比测定能量饲料RUP小肠消化率效果更好.用饲料的常规营养成分含量可较好地预测RUP小肠消化率.     

Effect of ileum segment and protein sources on net disappearance of crude protein and amino acids in laying hens

1. This study investigated the net disappearance of crude protein (CP) and amino acids (AA) from soybean meal and rapeseed meal in different sub-sections of the ileum of hens. A basal diet was used and in another 4 diets, maize starch contained in the basal diet was replaced with soybean meal or rapeseed meal at 140 and 280 g/kg so that changes in dietary AA concentrations resulted from the oilseed meals only. 2. A total of 250 Lohmann Brown pullets were used for this experiment at 20 weeks old and given one of the 5 diets for 7 d. The section between Meckel's diverticulum and 2 cm anterior to the ileo-caecal-colonic junction was taken after slaughtering the hens and cut into three sub-sections of equal length. Digesta were taken separately from each sub-section and then frozen. Net disappearance of AA and CP for the diets and the two protein sources was calculated based on standard equations and using a multiple linear regression approach. 3. Net disappearances of CP and all AA were significantly lower in the proximal sub-section than in the central and terminal sub-sections. Also, the net disappearance of CP and all AA from rapeseed meal was significantly lower in the proximal sub-section than in the central or terminal sub-sections. For soybean meal, only the net disappearances of arginine, aspartic acid, glutamic acid and phenylalanine were significantly lower in the proximal than in the terminal sub-section. No significant differences in the net disappearance of CP and AA were detected between protein sources within the central and terminal sub-sections or between the central and terminal sub-section within each protein source. Soybean meal had a significantly higher net disappearance of CP and AA (with the exception of cystine and methionine) than rapeseed meal in the proximal sub-section but these differences were not statistically significant in the central and terminal sub-sections. 4. Amino acids disappeared from the proximal region of the ileum. This needs consideration in standard approaches that are used for measuring AA digestibility. There is a variation in AA digestibility between soybean meal and rapeseed meal. The ranking of individual AA regarding their digestibility is different between the two oilseed meals.     

Effects of level of supplemental phytase on ileal digestibility of amino acids, calcium, and phosphorus in dehulled soybean meal for growing pigs.

Ileally cannulated pigs were used to assess the effects of four dietary levels of microbial phytase (Natuphos) on the apparent and true digestibility of Ca, P, CP, and AA in dehulled soybean meal. Fourteen pigs (25 kg initial BW) were surgically fitted with T-cannulas at the terminal ileum and assigned to diets in a replicated 7 x 7 Latin square design. Following a 14-d recovery, four diets consisting of 30.5% soybean meal with 0, 500, 1,000, or 1,500 units of phytase/kg of diet were fed. Diets 5 (1.05% lysine, 0.90% Ca, and 0.75% P) and 6 (1.05% lysine, 0.90% Ca, and 0.75% P) contained 35.25% soybean meal and 27.0% soy protein concentrate, respectively. Diet 7 (0.37% lysine, 0.03% Ca, and 0.05% P) was a low-CP, casein-based diet used to estimate the nonspecific endogenous losses of Ca, P, CP, and AA in order to estimate the true digestibility of these nutrients. All diets contained cornstarch and dextrose and were fortified with vitamins and minerals. Chromic oxide was used as an indigestible indicator. The diets were fed daily at 9% of metabolic BW (BW0.75). Apparent and true ileal digestibility of P increased quadratically (P < 0.01) and true digestibility of Ca increased linearly (P < 0.07) with increasing levels of phytase. Apparent digestibility of Ca was unaffected (P = 0.15) by phytase level. Apparent and true ileal digestibility of CP and most AA increased slightly with the addition of 500 units of phytase/kg of diet, but not at higher levels of phytase supplementation (in most cases, cubic effect, P < 0.05). Apparent and true ileal nutrient digestibility coefficients were unaffected by soybean meal source (Diet 1 vs Diet 5), except for arginine and Ca. The apparent and true digestibility coefficients for most of the AA tended (P < 0.10) to be lower in diets containing soy protein concentrate vs the common source of soybean meal used in Diet 5, but ileal digestibilities of Ca and P were unaffected (P = 0.15). In this study, supplemental microbial phytase did not improve the utilization of AA provided by soybean meal but was an effective means of improving Ca and P utilization by growing swine fed soybean meal-based diets.     

Effect of protein source and fumaric acid supplementation on apparent ileal digestibility of nutrients by young pigs

Two experiments were conducted to determine the apparent ileal digestibility of DM and N by young pigs fed diets supplemented with different protein sources or organic acids. Pigs were surgically fitted with silicone cannulas at 2 wk of age. Following surgery, pigs were allowed to recuperate with their dams while suckling normally. After weaning at 24 d, pigs were assigned to treatment diets at 28 d of age. A 3-d adjustment and 4-d collection sequence was followed for the duration of the 4-wk experiment. Four treatment diets were fed in each experiment in a weekly rotation until each diet had been fed to each pig. Diet samples and digesta collected through the ileal cannulas were analyzed for chromic oxide (used as an indigestible marker), DM, and N. Pigs in Exp. 1 were fed isolysinic (1.0%) corn-based diets supplemented with casein, soybean meal, soy protein concentrate, or isolated soy protein. Casein addition resulted in improved DM (P less than .001) and N (P less than .05) digestibility but reduced gain (P less than .05) compared with the average of the soy protein sources. Nitrogen from diets formulated with soybean meal was digested more completely (P less than .05) than N from diets based on soy protein concentrate and isolated soy protein. Experiment 2 was an evaluation of the effect of dried skim milk (25%) and fumaric acid (2%) addition on apparent ileal digestibility of N and DM in corn-soybean meal diets. Addition of dried skim milk improved DM (P less than .01) and N (P less than .05) digestibility and daily gain (P less than .001). Fumaric acid supplementation did not affect nutrient digestibility or gain (P greater than .10).     

Nutrients and toxicants in rapeseed meal: a review

The composition of rapeseed meal and hulls is reviewed with emphasis on components of nutritional interest. Carbohydrates in rapeseed meal are mainly pectins, pentosans and cellulose and comprise nearly one-half the gross energy. The digestibility of energy is lower for rapeseed than for soybean meal. Protein is well digested, but the protein digestion coefficient and the availability of amino acids are lower than for soybean meal. Data on digestible and metabolizable energy are summarized. The kinds of glucosinolates present in high (HG) and low (LG) glucosinolate rapeseed meal and the nature of their hydrolytic products are discussed. The toxic effects of oxazolidinethione , isothiocyanates, thiocyanates and nitriles, and their relationship to their parent glucosinolates , to myrosinase action and to conditions during rapeseed processing are reviewed briefly. The effects of glucosinolates in animal tissues and products and the effects of converting to LG rapeseed meal are presented. Finally, a brief review is given of the responses of swine and cattle to the feeding of HG and LG rapeseed meal. The nutritional advantages of LG rapeseed meal, over the older type HG meal, are clearly evident from the feeding trials.     

不同粉碎粒度的豆粕对断奶仔猪生长性能和养分消化率的影响

本试验研究不同粉碎粒度的豆粕对断奶仔猪生长性能和养分消化率的影响,选用26～28日龄断奶(7.9±0.7)kg杜×长×大健康仔猪80头,按体重、性别相同原则随机分为4个处理,每处理设5个重复,每个重复4头猪。各个处理组采用相同的日粮组成,对照组饲喂含常规粉碎豆粕(目标粒径为750μm)的日粮,处理1、2、3分别饲喂含目标粒径为150、30、6μm豆粕的日粮。结果表明:使用粉碎粒度低于30μm豆粕的日粮提高了断奶仔猪日增重(P<0.05),明显提高采食量(P>0.05),降低饲料增重比(P<0.05),显著降低断奶仔猪的腹泻频率;使用粉碎粒度低于30μm豆粕的日粮提高断奶仔猪日粮氮、磷表观消化率(P<0.05),改善能量消化率(P=0.063)和有机物表观消化率(P=0.082),显著提高必需氨基酸的表观消化率(P<0.05)。粉碎粒度低于30μm的超微粉碎豆粕可显著提高断奶仔猪日粮蛋白质的消化效率,提高断奶仔猪的生长性能,改善了豆粕作为蛋白质营养源的生物适应性。     

Apparent digestibility of nitrogen and amino acids in protein feedstuffs by growing pigs

Eight digestion trials were conducted with pigs fitted with ileal T-cannulas to determine the apparent digestibilities of N and amino acids in common protein feedstuffs. Trial-to-trial variation was minimal as determined by the variation in digestibilities for soybean meal, which was evaluated in each trial. Apparent digestibilities varied widely; ileal N digestibility ranged from 88 to 63%, and ileal lysine digestibility ranged from 93 to 40%. In general, ring-dried blood meal, corn gluten meal, Menhaden fish meal, poultry-by-product meal and extruded whole soybeans were the most digestible, followed by canola meal, sunflower meal, peanut meal and meat and bone meal. Cottonseed meal and feather meal were the least digestible. Mean values for each feedstuff agree well with published data. Variation in digestibilities among samples of the same feedstuff was greater for the meat and bone meals. Regression of ileal essential amino acid digestibilities on ileal and fecal N digestibility indicated that amino acid digestibilities can be predicted more precisely from ileal N digestibility than from fecal N digestibility. However, neither ileal nor fecal N digestibility could be used with a high degree of certainty to predict ileal amino acid digestibilities.     

热处理对大豆制品在生长猪回肠表观和真可消化氨基酸消化率的影响

试验比较了不同热处理时间大豆片、普通豆粕和去皮豆粕在生长猪回肠表观和真消化率的影响。试验采用12头回肠末端安装简单T型瘘管的生长猪,6×6有重复拉丁方设计。采用玉米淀粉-豆粕半纯合型日粮,配制酪蛋白日粮用以测定内源氮和氨基酸的损失量。结果表明:随着大豆片热处理时间的延长(0～18min),粗蛋白质和氨基酸的回肠表观和真消化率均显著提高(线性效应,P<0.01)。生大豆片的粗蛋白质和氨基酸的消化率显著低于普通豆粕和去皮豆粕(P<0.01),但普通豆粕与去皮豆粕间差异不显著(P>0.05)。