Standardized ileal digestibility of amino acids in soybean meal fed to non-pregnant and pregnant sows

Background Two studies were designed to determine standard ileal crude protein(CP)and amino acid(AA)digestibility of soybean meal(SBM)from different origins fed to non-pregnant and pregnant sows.Seven solvent-extracted SBMs from soybeans produced in the USA,Brazil,and China were selected.In Exp.1,eight different diets were created:a nitrogen(N)-free diet and 7 experimental diets containing SBM from different origins as the only N source.Eight non-pregnant,multiparous sows were arranged in an 8×8 Latin square design(8 periods and 8 diets).In Exp.2,the diet formula was the same as in Exp.1.Eight gestating sows(parity 3)were assigned to 4 different diets in a replicated 4×3 Youden square design(three periods and four diets)in mid-gestation and again in late-gestation stages.Results When fed to non-pregnant and late-gestating sows,the standardized ileal digestibility(SID)of CP and most AAs from different SBM were not significantly different(P>0.05).When fed to mid-gestating sows,the SID values for Arg,His,Lys,Phe,Cys,Gly,Ser,and Tyr in SBM 1 were lower than in SBM 4 and 5(P<0.05),whereas SID for Leu from SBM 5 was higher than in SBM 1 and 4(P<0.05).SID values for Ile,Ala,and Asp from SBM 4 were lower than in SBM 1 and 5(P<0.05).Sows had significantly greater SID values for Lys,Ala,and Asp during mid-gestation when compared with late-gestation stages(P<0.05).Mid-gestating sows had greater SID value for Val and lower SID value for Tyr when compared with non-pregnant and late-gestating sows(P<0.01),whereas non-pregnant sows had significantly greater SID value for Met when compared with gestating sows(P<0.01).Conclusions When fed to mid-gestating sows,the SID values for most AAs varied among SBM samples.The SID values for Lys,Met,Val,Ala,Asp,and Tyr in SBM were affected by sow gestation stages.Our findings provide a cornerstone for accurate SBM use in sow diets.

Determination of basal ileal endogenous losses and standardized ileal digestibility of amino acids in barley fed to growing pigs

Background： Basal ileal endogenous amino acid（AA） losses（IAAend） and standardized ileal digestibility（SID） values of cereal grains, such as barley, are apparently underestimated when determined according to the nitrogen（N）-free method. Regression analysis between the dietary apparent ileal digestible content（c AID） and total crude protein（CP） and AA can be considered as alternative approach to obtain more accurate values for IAAendand SID of AA in cereal grains.Methods： Eight hulled barley genotypes were used, with barley being the only source of CP and AA in the assay diets. The diets contained 95 % as-fed of these eight barley genotypes each, ranging in CP content between 109.1 and 123.8 g/kg dry matter（DM）. Nine ileally T-cannulated barrows, average body weight（BW） 30 ± 2 kg, were allotted to a row-column design comprising eight periods with 6 d each and nine pigs. On d 5 and the night of d 6 of every period, ileal digesta were collected for a total of 12 h. The IAAend and the SID were determined by linear regression analysis between c AID and total dietary CP and AA.Results： There exist linear relationships between cA ID and total CP and AA（P 〈 0.001）. The IAAend of CP, Lys, Met, Thr and Trp amounted to 35.34, 1.08, 0.25, 1.02 and 0.38 g/kg DM intake（DMI）, respectively, which are greater compared to average IAAend determined previously under N-free feeding conditions. The SID of CP, Lys, Met, Thr and Trp was 90,79, 85, 79 and 86 %, respectively, and was greater when compared to tabulated values. Moreover, these SID values were greater than those reported in literature, based on correction of apparent ileal digestibility（AID） of CP and AA for their IAAendvalues. Summarized, the results of the present regression analysis indicate greater IAAendin barley-based diets compared to those obtained by N-free feeding.Conclusions： For low-protein feed ingredients like barley the regression method may be preferred over correction of AID values for their IAAenddetermined under N-free feeding conditions, as intercepts and slopes of the linear regression equations between cA ID and total dietary CP and AA provide direct estimates of IAAendand SID of CP and AA in the presence of the assay feed ingredient.

Oils with different degree of saturation:effects on ileal digestibility of fat and corresponding additivity and bacterial community in growing pigs

Background Oils are important sources of energy in pig diets.The combination of oils with different degree of saturation contributes to improve the utilization efficiency of the mixed oils and may reduce the cost of oil supplemented.An experiment was conducted to evaluate the effects of oils with different degree of saturation on the fat digestibility and corresponding additivity and bacterial community in growing pigs.Methods Eighteen crossbred(Duroc×Landrace×Yorkshire)barrows(initial body weight:29.3±2.8 kg)were surgically fitted with a T-cannula in the distal ileum.The experimental diets included a fat-free basal diet and 5 oil-added diets.The 5 oil-added diets were formulated by adding 6%oil with different ratio of unsaturated to saturated fatty acids(U:S)to the basal diet.The 5 oils were palm oil(U:S=1.2),canola oil(U:S=12.0),and palm oil and canola oil were mixed in different proportions to prepare a combination of U:S of 2.5,3.5 and 4.5,respectively.Results The apparent and standardized ileal digestibility(AID and SID)of fat and fatty acids increased linearly(P<0.05)as the U:S of dietary oils increased except for SID of fat and C18:2.The AID and SID of fat and fatty acids differed among the dietary treatments(P<0.05)except for SID of unsaturated fatty acids(UFA)and C18:2.Fitted one-slope broken-line analyses for the SID of fat,saturated fatty acids(SFA)and UFA indicated that the breakpoint for U:S of oil was 4.14(R^(2)=0.89,P<0.01),2.91(R^(2)=0.98,P<0.01)and 3.84(R^(2)=0.85,P<0.01),respectively.The determined SID of fat,C18:1,C18:2 and UFA in the mixtures was not different from the calculated SID of fat,C18:1,C18:2 and UFA.However,the determined SID of C16:0,C18:0 and SFA in the mixtures were greater than the calculated SID values(P<0.05).The abundance of Romboutsia and Turicibacter in pigs fed diet containing palm oil was greater than that in rapeseed oil treatment group,and the two bacteria were negatively correlated with SID of C16:0,C18:0 and SFA(P<0.05).Conclusions The optimal U:S for improving the utilization efficiency of mixed oil was 4.14.The SID of fat and UFA for palm oil and canola oil were additive in growing pigs,whereas the SID of SFA in the mixture of two oils was greater than the sum of the values of pure oils.Differences in fat digestibility caused by oils differing in degree of saturation has a significant impact on bacterial community in the foregut.

Estimation of endogenous protein and amino acid ileal losses in weaned piglets by regression analysis using diets with graded levels of casein

Background： Many studies have investigated endogenous loss of proteins and amino acids （AAs） at the ileal level in growing pigs. However, only a few studies have researched this subject in piglets. Knowledge regarding AA ileal digestibility in piglets would be helpful during the formulation of diets for weaning piglets, rather than just using coefficients obtained in growing pigs. Therefore, in this study, we sought to estimate endogenous protein and AA ileal losses in piglets. Furthermore, apparent and true ileal digestibility （AID and TID） of protein and AAs from casein were measured. Results： The average flow of protein was 20.8 g/kg of dry matter intake （DMI）. Basal protein loss, as estimated by regression, was 16.9 g/kg DMI. Glutamic acid, arginine, and aspartic acid （2.2, 1.4, and 1.2 g/kg DMI, respectively） were the AAs for which greater losses were seen. The AID of protein and AAs increased as the protein level in the diet increased. A higher increment in AID was observed between diets with 80 and160 g CP/kg of feed; this finding was mainly attributable to increases in glycine and arginine （46.1% and 18%, respectively）. The TID of protein was 97.8, and the TID of AAs varied from 93.9 for histidine to 100.2 for phenylalanine. Conclusions： The basal endogenous protein loss in piglets was 16.9 g/kg DMI. Endogenous protein was rich in glutamic acid, aspartic acid, and arginine, which represented 32.7% of endogenous protein loss in weaning piglets. The TID of casein was high and varied from 93.0 for histidine to 100.2 for phenylalanine.

Effect of protease supplementation on apparent ileal crude protein and amino acid digestibility of over-processed soybean meals in broilers

Background: Nutritional value of proteins in feed ingredients can be negatively affected by hydrothermal processing, which causes large variation in the bioavailability of amino acids(AA) and negatively affects animal productive performance. Supplementation of exogenous proteases could increase the rate of digestion of damaged proteins, thereby increasing overall AA digestibility and bioavailability. The aim was to determine the effect of exogenous protease supplementation on the apparent ileal digestibility(AID) of crude protein(CP) and AA of soybean meals(SBM) with different degrees of hydrothermal processing in broilers.Methods: The experiment involved a 3 × 2 factorial arrangement, with SBM processing time(commercial SBM or autoclaved for 30 or 60 min at 120 ℃) and protease supplementation(not supplemented and supplemented) as factors. Protease was included at three times the recommended dose(0.06%) and the experimental diets were fed from 15 to 21 d.Results: The interaction between the effects of SBM processing and protease supplementation was significant for the AID of CP(P = 0.01), Trp(P = 0.01), Gly(P = 0.03) and Pro(P = 0.03), and also for the average daily gain(P = 0.01)and feed conversion ratio(P = 0.04). Increasing the processing time of SBM decreased(P < 0.0001) the AID of all amino acids, whilst the effect of protease supplementation was only significant for the AID of Phe(P = 0.02) and Tyr(P = 0.01).Conclusions: Exogenous protease supplementation at three times the commercial dose does not seem to offset the negative effects of hydrothermal processing of SBM on the apparent ileal digestibility of CP and amino acids or performance of broilers. Whilst positive numerical improvements of digestibility and performance(ADG and FCR)were noticed with protease supplementation at relatively mild processing levels, negative results were obtained with the harsh-processed meals.

Chemical composition,energy and amino acid digestibility in double-low rapeseed meal fed to growing pigs

Background： The nutritional value of rapeseed meal may be variable due to the variation of its chemical composition. And a precise understandin9 of the nutritional value of an ingredient is beneficial for the accurate diet formulation and reduction of feed costs. This study was conducted to determine the chemical composition, dicjestible energy （DE） and metabolizable enercjy （ME） content, and apparent ileal digestibility （AID） and standardized ileal dicjestibility （SID） of amino acids （AA） for growincj pigs. Thirteen solvent-extracted double-low rapeseed meal （DLIRSM） samples were obtained from the main double-low rapeseed producing areas in China. Methods： The DE and ME contents of the 13 DLRSM samples were measured in cjrowin9 pigs （six pigs per DLRSM sample, average initial body weicjht （BW） =48.3 kg）. The AID and SID of AA of 10 DLRSM samples were determined in 12 crossbred barrows （average initial BW = 35.3 kcj） by using two 6 x 6 Latin square designs. Each Latin square comprised one N-flee diet and 5 DLRSM test diets. Results： The chemical composition of DLRSM varied among samples, and the coefficient of variation was greater than ]0 % for ether extract （EE）, neutral detergent fiber （NDF）, acid detergent fiber （ADF）, calcium （Ca）, and total 91ucosinolates. The AA content of DLRSM varied among samples especially for lysine （Lys） and methionine （Met）. On a dry matter （DM） basis, the apparent total tract digestibility （ATFD） of gross energy （GE）, the DE and ME and the ME：DE ratio of DLRSM averaged 62.39 %, 2862 kcal/k9 and 2723 kcal/kcj, and 94.95 %, respectively. The mean value of S1D of Lys was 70.52 % which varied from 66.54-76.54 %. The SID of crude protein （CP）, Met, and threonine （Thr） averaged 72.81%, 82.41%, and 69.76 %, respectively. Conclusions： There was great variability in chemical composition especially in the concentration of EE, NDF and ADF, but no significant differences in energy content of the DLIRSM samples were observed. In addition, the AID and SID of all AA were relatively similar amoncj DLRSM samples except for that of Lys.

以可消化蛋白质为基础的水产低蛋白质饲料发展方向与技术分析

依据动物营养学理论,水产动物对饲料蛋白质和氨基酸的营养需要量就是在满足动物生长性能和生理健康条件下的饲料蛋白质和氨基酸的最低需要量。水产饲料中过高的粗蛋白含量既违背动物营养理论,又造成饲料资源的严重浪费,同时显著增加了对养殖水体中的氮输入量。因此,发展低蛋白质含量、高质量的水产饲料是必需的。这类饲料可以称之为实现了理想蛋白质模型的低蛋白质水产饲料。水产动物理想蛋白质模型是以饲料中可消化蛋白质的量、可消化氨基酸的量为基础计算和配制的,同时也要保持很好的氨基酸平衡性。构建饲料原料中蛋白质和氨基酸消化率数据库是发展理想蛋白质模型水产饲料的技术核心。采用工业化酶解技术和微生物发酵技术,可以显著提高饲料原料中蛋白质和氨基酸的消化利用率,或者开发出蛋白质、氨基酸消化率很高的新的饲料原料,这类原料在饲料中的应用,是发展低蛋白质含量、高质量水产饲料的重要保障。水产饲料产品质量标准是水产饲料工业和水产养殖业发展的重要技术保障。因此,水产饲料产品质量标准也要增加饲料中可消化蛋白质和氨基酸含量的技术指标和含量。

Comparative standardized ileal amino acid digestibility and metabolizable energy contents of main feed ingredients for growing pigs when adding dietary β-mannanase

The present study was conducted to test whether the dietary supplementation of β-mannanase affects amino acids(AA) digestibility,metabolizable energy(ME) contents of corn,wheat,soybean meal,distillers dried grains with solubles,and palm kernel meal(PKM),nutrient digestibility,and growth performance of pigs.In Exp.1,22 cannulated pigs were used for 10 dietary treatments including 5 feed ingredients and 2 β-mannanase concentrations(0 and 0.5 g/kg of the diet) in 6 periods in an incomplete Latin square design to determine the AA and energy digestibility.In Exp.2,200 growing pigs were randomly allotted to 4 treatments with 2 nutrient levels(high and low) and 2 concentrations of β-mannanase(2×2 factorial arrangement) in 2 phases(phase 1,d 0 to 21;and phase 2,d 22 to 42).In Exp.1,β-mannanase increased the mean standardized ileal digestibility(SID) of AA in all feed ingredients.The amount of digestible energy was increased(P <0.05) in β-mannanase-treated PKM.Pigs fed β-mannanase showed a greater(P <0.05) digestibility of gross energy(GE).The feed-to-gain(F:G) ratio was improved(P <0.01) in pigs fed high-nutrient diets.Pigs fed β-mannanase in the diets had greater(P <0.05) average daily gain and F:G.In phase 2,the concentration of fecal ammonia was decreased(P <0.05) in pigs fed β-mannanase.Considering the 2 experiments,it can be concluded that β-mannanase increases the SID of AA,which has to be considered in balancing the rations.

快速型黄羽肉鸡玉米代谢能值及氨基酸标准回肠消化率评定

本试验旨在评估快速型黄羽肉鸡玉米代谢能值和氨基酸标准回肠消化率(SID),并基于玉米有效化学成分构建其表观代谢能(AME)预测方程。试验1:评估快速型黄羽肉鸡玉米的AME和氮校正表观代谢能(AMEn)。选取396羽湘佳黄鸡2号肉公鸡(属快速型黄羽肉鸡),随机分成11个组,每组6个重复,每个重复6羽。随机选择1组饲喂基础饲粮,其余10组饲喂试验饲粮,试验饲粮用不同来源的玉米替换40%的基础饲粮配制。试验分2个阶段进行,12~18日龄为阶段1,33~39日龄为阶段2。试验2:评估快速型黄羽肉鸡玉米的氨基酸SID。选取396羽湘佳黄鸡2号肉公鸡,随机分成11组,每组6个重复,每个重复6羽。随机选择1组饲喂无氮饲粮,另外10组饲喂以不同来源玉米为主要原料的试验饲粮。试验分2个阶段进行,14~18日龄为阶段1,35~39日龄为阶段2。结果显示:1)10种不同来源玉米中干物质(DM)、粗蛋白质(CP)、粗脂肪(EE)、粗纤维(CF)、粗灰分(Ash)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)含量的平均值分别为85.67%(84.95%~86.15%)、7.40%(6.73%~8.24%)、2.87%(2.43%~3.04%)、3.43%(1.12%~6.18%)、0.90%(0.67%~1.12%)、14.00%(12.49%~16.09%)、2.74%(2.40%~3.07%),总能(GE)的平均值为18.55 MJ/kg(18.25~18.74 MJ/kg)。2)在干物质基础上,快速型黄羽肉鸡对10种玉米的AME和AMEn的平均值在12~18日龄分别为12.96和12.62 MJ/kg,在33~39日龄分别为13.06和12.73 MJ/kg。3)14~18日龄快速型黄羽肉鸡对玉米必需氨基酸中SID最高的是组氨酸,平均值为82.53%。35~39日龄快速型黄羽肉鸡对玉米必需氨基酸中SID最高的是蛋氨酸,平均值为86.97%。4)12~18日龄快速型黄羽肉鸡对玉米AME的最佳预测方程为:AME(MJ/kg)=41.26-0.10DM+1.00EE-0.94CP-0.49CF-7.46Ash-0.16NDF-1.88ADF(R^(2)=0.78,P=0.593);33~39日龄快速型黄羽肉鸡对玉米AME的最佳预测方程为:AME(MJ/kg)=15.28-2.37Ash(R^(2)=0.47,P=0.029)和AME(MJ/kg)=-25.19+0.52DM+1.56EE-0.43CP-0.12CF-5.23Ash+0.02NDF-0.84ADF(R^(2)=0.94,P=0.195)。综上所述,快速型黄羽肉鸡对不同来源玉米的AME、AMEn和氨基酸SID均存在较大差异,Ash是快速型黄羽肉鸡玉米AME的最佳预测因子。

发酵花生粕的营养价值评定及其对仔猪生长性能的影响

研究旨在评定发酵花生粕(FPM)的营养价值并研究其对断奶仔猪生长性能影响。试验分为3个部分。试验1:将12头初重为(10.0±2.0) kg的“杜×长×大”三元去势公猪随机分为2组,分别饲喂基础饲粮和FPM饲粮,每组6个重复,每个重复1头猪。利用全收粪法测定两种饲粮的有效能值,并通过套算法计算FPM的猪消化能与代谢能。试验2:选取12头回肠末端安装T型瘘管的初重为(15.0±2.0) kg的“杜×长×大”三元去势公猪随机分为2组,分别饲喂无氮饲粮和以30%FPM为唯一氮源的半纯合饲粮,每组6个重复,每个重复1头猪。试验期7 d,于最后2 d收集回肠末端食糜以测定FPM的表观回肠消化率(AID)和标准回肠消化率(SID)。试验3:将50头初重为(8.0±1.0) kg的断奶仔猪(公、母各半)随机分为5组,每组10个重复,每个重复1头猪。对照组饲喂玉米-豆粕型基础饲粮,试验组分别饲喂添加2%、4%、6%、8%的FPM试验饲粮,试验期21 d。结果显示:FPM (风干基础)的消化能和代谢能分别为15.17和13.83 MJ/kg,其赖氨酸、蛋氨酸、苏氨酸、色氨酸的SID分别为85.85%、92.44%、87.80%、84.09%。与对照组相比,饲粮中添加FPM对断奶仔猪的平均日采食量和腹泻率无显著影响(P>0.05);添加2%~8%FPM可显著增加平均日增重(P<0.05),降低料重比(P<0.05)。研究表明,FPM的有效能值和氨基酸利用率较高,在断奶仔猪饲粮中添加2%~8%FPM可降低仔猪料重比,其中6%添加比例的饲喂效果较好。

肉鸭对糖渣和酱油渣养分利用率评定

【目的】试验旨在对糖渣和酱油渣进行营养价值评定,测定其在肉鸭中的营养物质消化率、代谢能和回肠氨基酸消化率。【方法】代谢能及养分消化率采用排空-强饲法测定,共选取24只肉鸭,随机分为糖渣组和酱油渣组,每组12个重复,每重复1只鸭,强饲量为60 g,排空和集粪时间均为48 h,收集肉鸭粪便样品,测定干物质、粗蛋白质、粗脂肪、粗纤维、中性洗涤纤维、酸性洗涤纤维含量和总能。使用无氮饲粮法和回肠末端法测定回肠氨基酸消化率,选取60只肉鸭,随机分为糖渣组、糖渣无氮饲粮组、酱油渣组和酱油渣无氮饲粮组,每组5个重复,每重复3只鸭,适应期3 d后分别饲喂试验饲料,4 h后统一屠宰取回肠内容物,测定氨基酸含量。【结果】糖渣中干物质含量为89.70%、粗蛋白质为21.98%、总能为26.47 MJ/kg;酱油渣中干物质含量为89.53%,粗蛋白质含量为26.65%,总能为24.06 MJ/kg。代谢试验结果表明,糖渣和酱油渣在肉鸭中的表观代谢能分别为18.09和8.59 MJ/kg,干物质消化率分别为57.46%和44.61%,粗脂肪消化率分别为84.88%和84.43%。回肠氨基酸消化率结果显示,糖渣和酱油渣试验中表观回肠消化率最高的是赖氨酸,分别为92.75%和55.60%。【结论】糖渣和酱油渣粗蛋白质含量高,氨基酸含量和组成丰富,肉鸭对粗脂肪和粗蛋白质利用率较高,可以开发作为肉鸭饲料原料应用在生产中。

杂粕饲粮中添加水解鱼蛋白肽对肉鸡生长性能、屠宰性能、肉品质及氨基酸表观回肠消化率的影响

本试验旨在研究杂粕饲粮中添加不同水平的水解鱼蛋白肽对肉鸡生长性能、屠宰性能、肉品质及氨基酸表观回肠消化率的影响。选用300只体重相近、体况良好的1日龄爱拔益加(AA)肉仔鸡,随机分为5组,每组6个重复,每个重复10只鸡。对照组饲喂玉米-杂粕型基础饲粮(4%菜籽粕+5%棉籽粕),试验组分别在杂粕饲粮中添加1%、2%、3%和4%水解鱼蛋白肽,并配制成等能等氮的全价饲料。试验期42 d。结果表明:1)与对照组相比,添加1%水解鱼蛋白肽显著提高肉鸡42日龄体重、22~42日龄平均日采食量以及1~42日龄平均日增重和平均日采食量(P<0.05)。2)与对照组相比,添加4%水解鱼蛋白肽显著提高肉鸡半净膛率和全净膛率(P<0.05),添加2%水解鱼蛋白肽显著提高全净膛率(P<0.05)。3)与对照组相比,添加1%水解鱼蛋白肽显著提高肉鸡胸肌红度(a)和黄度(b)值(P<0.05),显著降低胸肌pH 45 min和剪切力(P<0.05),显著降低腿肌pH 45 min和pH_(2)4 h(P<0.05)。4)与对照组相比,1%水解鱼蛋白肽组蛋氨酸、苏氨酸、缬氨酸、谷氨酸、甘氨酸、天冬氨酸和脯氨酸表观回肠消化率显著提高(P<0.05)。综上所述,肉鸡杂粕饲粮中添加1%水解鱼蛋白肽可提高其生长性能,改善肉品质,同时促进氨基酸的消化吸收。

肉鸡标准回肠氨基酸消化率测定研究进展及存在的问题

低蛋白日粮是畜禽营养发展的重要方向。基于标准回肠氨基酸消化率(Standard ileal amino acid digestibility, SIAAD)计算的肉鸡饲料配方能够更加准确合理的反映家禽对饲料蛋白质的消化能力、减少氮的排泄。因而采用标准回肠氨基酸消化率设计日粮配方是实现低蛋白营养的前提。文章综述了家禽标准回肠氨基酸消化率测定研究进展及存在的问题,以期为建立原料标准回肠氨基酸消化率参数数据库提供参考。

发酵大米蛋白、酶解鱼蛋白肽和鱼粉对生长猪有效能和回肠末端氨基酸消化率的影响

试验旨在研究发酵大米蛋白(FRP)、酶解鱼蛋白肽(EHFP)和鱼粉(FM)对生长猪消化能(DE)、代谢能(ME)和回肠末端氨基酸消化率的影响。试验1:选用24头健康的“杜×长×大”三元杂交去势公猪,平均体重(15.27±1.12)kg,随机分为对照组(基础饲粮)、FRP组(20%FRP)、EHFP组(20%EHFP)和FM组(20%FM),每组6个重复,每个重复1头猪,采用全收粪法测定其消化能、代谢能和总能的全肠道表观消化率。试验2:选用12头平均体重为(18.36±1.35)kg的装有T型瘘管的“杜×长×大”三元杂交去势公猪,采用4×2尤登方设计,随机分为对照组(无氮饲粮)、FRP组(25%FRP)、EHFP组(30%EHFP)和FM组(20%FM),每组3个重复,每个重复1头猪,采用指示剂法计算氨基酸在表观回肠末端的消化率(AID)在和标准回肠末端的消化率(SID)。结果显示:FPR组生长猪的DE、ME(饲喂基础)分别为19.28、17.64 MJ/kg,EHFP组生长猪的DE、ME(饲喂基础)分别为21.93、19.92 MJ/kg,FM组生长猪的DE、ME(饲喂基础)分别为15.12、13.48 MJ/kg。FRP组、EHFP组的氨基酸SID分别为73.06%~88.66%、87.98%~94.92%。FRP组、EHFP组的DE、ME均显著高于FM组(P<0.05)。除蛋氨酸、丙氨酸、天冬氨酸和脯氨酸外,EHFP组其他氨基酸的SID均显著高于FM组(P<0.05);FRP组的蛋氨酸SID显著低于FM组(P<0.05),苏氨酸、脯氨酸和酪氨酸的SID显著低于FM组(P<0.05)。研究表明,根据有效能和氨基酸SID结果判断,FPR和EHFP可作为新型的优质蛋白饲料应用于猪生产中。

Effects of corn gluten feed inclusion at graded levels in a corn-soybean diet on the ileal and fecal digestibility of growing pigs

Background： This study aimed to determine the effect of the inclusion of corn gluten feed （CGF） on the apparent and standardized ileal digestibility of protein and amino acids and the apparent ileal and total tract digestibility of energy in growing pigs. The study was performed using 16 barrows （weight, 45.3 ±4.5 kg） that were fitted with a T cannula at the terminal ileum. There were four treatments： a corn-soybean diet without CGF and three corn-soybean diets containing increasing levels of CGF （65, 130, and 195 g/kg）. Data were analyzed according to a randomized complete block design, four blocks with four pigs each （one pig per treatment）. The trend of the response （linear or quadratic） was determined using orthogonal contrasts, and when a linear effect was determined, a linear equation was obtained. Results： The results showed that the inclusion up to 195 g/kg of CGF in the corn-soybean diet did not diminish the ileal digestibility （apparent and standardized） of protein and amino acids （P 〉 0.05）, except that of phenylalanine, cystine, and proline. A linear decrease （P 〈 0.05） per gram of CGF added to the diet in the apparent and standardized ileal digestibility of phenylalanine （0.011 and 0.015 percentage units, respectively）, cystine （0.048 and 0.043 percentage units, respectively）, and proline （0.045 and 0.047 percentage units, respectively） was noted. Similarly, ileal digestibility of dry matter and energy were adversely affected （reduced by 0.028 and 0.025 percentage units, respectively, per gram of CGF increment in the diet）. A significant （P 〈 0.05） linear reduction in total tract digestibility with increase in CGF amount in the diet was observed for energy （0.027 percentage units）, dry matter （0.027 percentage units）, crude protein （0.020 percentage units）, and neutral detergent fiber （0.041 percentage units） per gram of CGF added to the diet. Conclusion： CGF did not affect the ileal digestibility of protein and most amino acids but reduced the ileal and total tract digestibility of energy.

复合酶制剂对肉鸭稻谷表观代谢能和标准回肠氨基酸消化率的影响

本试验旨在研究复合酶制剂对肉鸭稻谷表观代谢能(AME)和标准回肠氨基酸消化率(SIDAA)的影响。试验采用2×5+2设计,设5种不同来源的稻谷样品,复合酶制剂添加与否,1个饥饿组(后续用作无氮饲粮组),1个基础饲粮组,共12个组。在所有试验饲粮和无氮饲粮均添加0.5%二氧化钛(TiO2)作为外源指示剂,试验饲粮稻谷替代比例为30%,复合酶制剂添加量为300 mg/kg。结果表明:1)5种不同来源稻谷的粗纤维、酸性洗涤纤维、总磷、支链淀粉、直链淀粉和17种氨基酸含量的变异系数均超过15%。2)稻谷来源对饲粮和稻谷AME均存在显著影响(P<0.05)。添加复合酶制剂后,稻谷AME提高了1.22 MJ/kg(P>0.05),饲粮AME提高了0.36 MJ/kg(P>0.05)。3)除了蛋氨酸(Met)、精氨酸(Arg)和半胱氨酸(Cys)外,稻谷来源对SIDAA均存在显著影响(P<0.05)。添加复合酶制剂后,必需氨基酸赖氨酸(Lys)的SIDAA显著提高了11.80%(P<0.05),非必需氨基酸天冬氨酸(Asp)的SIDAA显著提高了7.75%(P<0.05)。由此可见,不同来源稻谷的化学成分含量、AME和SIDAA均存在较大差异,添加复合酶制剂可提高稻谷的营养价值。

食品中蛋白质质量评价方法的研究进展

不同食物中蛋白质的种类和含量不同,其氨基酸组成及比例也不同,因而对满足人体营养需求的贡献不同。蛋白质作为食物最基本的营养成分,其质量直接影响着人体健康。在全球人口激增、资源有限的情况下,科学合理的蛋白质质量评价方法对于人类合理膳食、获取充足营养、有效开发新型蛋白质资源等是非常重要的。因此,本文综合分析了食品中蛋白质质量评价方法的发展,并对蛋白质消化率校正氨基酸评分(protein digestibility corrected amino acid score,PDCAAS)和可消化氨基酸评分(digestibility indispensable amino acid score,DIAAS)展开详细讨论,重点阐述这两种评价方法的应用状况、优势及局限性,以期为探索优质蛋白质来源、研究蛋白质互补和开发高质量蛋白食品提供理论依据。

西洋参中氨基酸含量影响因素研究

目的:测定不同生长年限、不同产地、不同部位西洋参中氨基酸组成及含量,探究影响西洋参氨基酸含量的因素。方法:选用威海不同生长年限西洋参的主根、茎叶、果实,新疆、莱芜、黑龙江、辽宁、加拿大、美国等地4年生西洋参主根以及陕西4年生的主根、须根、侧根、芦头为研究对象,利用微波消解仪和氨基酸分析仪测定氨基酸组成及含量,并通过计算氨基酸比值和氨基酸比值系数进行营养学评价。结果:随着生长年限的增加,西洋参根部多数氨基酸含量呈“V”字型变化,在生长的第3年氨基酸含量达到最低值,之后明显上升;西洋参茎叶中多数氨基酸含量呈逐年递减的趋势;西洋参果实中多数氨基酸含量随生长年限呈现先增长后下降的趋势。威海和辽宁的西洋参总氨基酸含量较高。不同部位西洋参氨基酸含量积累规律为果实>根部>茎叶;西洋参根部多数氨基酸含量的不同部分积累规律为须根>芦头>侧根>主根。结论:生长年限、产地以及部位均可影响西洋参氨基酸含量,为今后西洋参的道地产区种植、采收期选择及各部位的开发利用提供了研究基础。

湿态发酵豆粕在快大型黄羽肉鸡上代谢能和氨基酸回肠消化率研究

本研究旨在评价湿态发酵豆粕在快大型黄羽肉鸡上代谢能和氨基酸回肠消化率。试验1:评估湿态发酵豆粕表观代谢能(AME)和氮校正表观代谢能(AME n)。选取48只30日龄快大型黄羽肉公鸡,随机分2组,每组6个重复,每个重复4只鸡。2组分别饲喂基础饲粮和试验饲粮。预试期3 d,全收粪期4 d。试验2:评估湿态发酵豆粕的氨基酸回肠消化率。选取72只30日龄快大型黄羽肉公鸡,随机分为2组,每组6个重复,每个重复6只鸡。2组分别饲喂无氮饲粮和试验饲粮。试验期3 d。试验1结果表明:饲喂基础下,湿态发酵豆粕的AME和AME n均显著低于普通豆粕(P<0.05);干物质基础下,湿态发酵豆粕的AME和AME n均显著高于普通豆粕(P<0.05)。试验2结果表明,必需氨基酸表观回肠消化率(AID)前4位分别为蛋氨酸(82.55%)、精氨酸(81.66%)、酪氨酸(80.64%)、色氨酸(80.50%),必需氨基酸标准回肠消化率(SID)前4位分别为色氨酸(97.89%)、蛋氨酸(91.26%)、精氨酸(88.20%)、异亮氨酸(87.52%)。非必需氨基酸AID前3位分别为谷氨酸(80.75%)、天冬氨酸(74.17%)、脯氨酸(72.95%),非必需氨基酸SID前3位由高到低分别为脯氨酸(86.56%)、谷氨酸(84.79%)、丝氨酸(83.17%)。由于湿态发酵豆粕水分含量较高,饲喂基础下,氨基酸含量均明显低于普通豆粕。干物质基础下,湿态发酵豆粕氨基酸含量(除色氨酸外)均略低于普通豆粕。必需氨基酸中,湿态发酵豆粕蛋氨酸、苏氨酸和色氨酸SID高于普通豆粕。由此可见,湿态发酵豆粕干物质基础的AME和AME n分别为14.38和13.20 MJ/kg,分别比普通豆粕高25.3%和27.3%,表明豆粕发酵后能提升代谢能。豆粕发酵后,蛋氨酸、苏氨酸和色氨酸SID有所提升。

Is the kafirin profile capable of modulating the ileal digestibility of amino acids in a soybean meal-sorghum diet fed to pigs?

The effects of kafirins on protein and amino acid ileal digestibility have not been evaluated in vivo in pigs.The aim of this study was to determine the effects of protein profile on apparent ileal digestibility(AID)of amino acids. We used a sorghum hybrid with low tannin content(<0.5%). The same hybrid was harvested from 2 different plots with different kafirin profile. Sorghum with greater content of total kafirins had less content of y-and al-kafirins and higher content of β-and a2-kafirins than that with lower content of total kafirins. Two sorghum-soybean meal(SBM) diets were formulated: 1) low kafirin(LK) content(32.2 g/kg) and 2) high kafirin(HK) content(48.1 g/kg). A control diet(maize-SBM) and a reference SBM-diet were also prepared. The reference diet was fed to all pigs following the experimental period and was used to estimate the AID of cereals by the difference method. 'T' cannulas were fixed in the distal ileum of 18 barrows(6 by treatment), divided into 2 groups of 9 pigs. The pigs were fed 2.5 times their maintenance requirement of digestible energy(110 kcal/kg BW00.75). The AID of dry matter,protein, amino acids, and energy of the experimental diets was measured;the AID of cereals(maize, LK sorghum and HK sorghum) was estimated by the difference method. The maize-SBM diet was more digestible than the sorghum-SBM diets, only with respect to valine(P < 0.05). The AID of valine in the maize-SBM diet was higher than that in sorghum-SBM diets. The changes in kafirin profile between the diets only affected the AID of threonine(P < 0.01), which decreased by 9.5 percentage units in LK diet compared with HK diet. Regarding the AID of cereals, maize exhibited greater AID than sorghum, with respect to valine(P < 0.01) and serine(P < 0.10). A comparison of sorghum with LK and HK content showed that the AID of threonine and serine increased by 50.5(P < 0.001) and 19.2 percentage units(P < 0.05) in the latter, respec:tively. The higher content of γ-kafirins in LK sorghum negatively affected threonine and serine digestibility, implying that the AID of amino acids is affected more by the profile than the content of kafirins.