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.

Nutritional value of a partially defatted and a highly defatted black soldier fly larvae (Hermetia illucens L.) meal for broiler chickens: apparent nutrient digestibility,apparent metabolizable energy and apparent ileal amino acid digestibility

Background: The study aimed to determine the apparent total tract digestibility coefficients(ATTDC) of nutrients, the apparent metabolizable energy(AME and AMEn) and the amino acid(AA) apparent ileal digestibility coefficients(AIDC)of a partially defatted(BSFp) and a highly defatted(BSFh) black soldier fly larvae meal. The experimental diets were: a basal diet and two diets prepared by substituting 250 g/kg(w/w) of the basal diet with BSFp or BSFh, respectively.Results: Significant differences were found between BSFp and BSFh meals for ATTDC of the nutrients: BSFp resulted more digestible than BSFh, except for ATTDC of CP which did not differed between meals, while a statistical trend was observed for ATTDC of DM and EE. The AME and AMEn values were significantly(P < 0.05) different between the two BSF meals, with higher levels for BSFp(16.25 and 14.87 MJ/kg DM, respectively). The AIDC of the AA in BSFp ranged from 0.44 to 0.92, while in BSFh they ranged from 0.45 to 0.99. No significant differences were observed for the AA digestibility(0.77 and 0.80 for BSFp and BSFh, respectively), except for glutamic acid, proline and serine that were more digestible in the BSFh meal(P < 0.05).Conclusions: Defatted BSF meals can be considered as an excellent source of AME and digestible AA for broilers with a better efficient nutrient digestion. These considerations suggested the effective utilization of defatted BSF larvae meal in poultry feed formulation.

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.

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.

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.

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.

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.

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.

全收粪法与回肠食糜法测定鸭饲粮氨基酸消化率的比较研究

本试验旨在研究全收粪法与回肠食糜法测定肉鸭内源氨基酸损失、饲粮标准氨基酸消化率的差异及其可加性,为选择更合适的肉鸭饲粮氨基酸效价评定方法提供参考。试验选用48只20周龄雄性北京鸭,随机分为2组:全收粪组和取回肠食糜组,每组采用单因素完全随机区组设计,包括4个饲粮处理:以玉米和豆粕分别为唯一蛋白质源配制的玉米饲粮和豆粕饲粮、玉米-豆粕型全价饲粮以及1种无氮饲粮,饲粮中均添加0.5%二氧化钛(TiO_(2))作为指示剂,每个处理6个重复,每个重复1只鸭。采集经肉鸭消化后的粪便或食糜样品,全收粪组通过差量法和指示剂法2种方式、取回肠食糜组通过指示剂法计算得到饲粮标准氨基酸消化率。结果表明:1)通过全收粪-指示剂法测定的无氮饲粮下肉鸭苯丙氨酸、苏氨酸、缬氨酸及总氨基酸的内源损失均显著低于回肠食糜法(P<0.05)。2)全收粪-差量法、全收粪-指示剂法和回肠食糜法测定的玉米饲粮标准氨基酸消化率均有超过100%的氨基酸,3种方法测定的标准氨基酸消化率在玉米饲粮中除蛋氨酸、玉米-豆粕型饲粮中除天冬氨酸和谷氨酸外均无显著差异(P>0.05)。3)单样本t检验表明,回肠食糜法测定的玉米-豆粕型饲粮的可消化氨基酸含量的实测值与计算值间均无显著差异(P>0.05),全收粪-差量法和全收粪-指示剂法测定的玉米-豆粕型饲粮的总可消化氨基酸含量的实测值均显著小于计算值(P<0.05)。由此可见,全收粪法和回肠食糜法测定的饲粮标准氨基酸消化率具有可比性,但回肠食糜法测得的饲粮标准氨基酸消化率的可加性更好。

肉鸡常规与低蛋白质饲粮净能效率和氨基酸标准回肠消化率比较研究

本试验旨在比较不同日龄肉鸡对常规与低蛋白质饲粮净能利用效率和氨基酸标准回肠消化率的差异。试验分2个试验进行,试验1:分别选择7日龄爱拔益加(AA)肉鸡48只、17日龄AA肉鸡48只和30日龄AA肉鸡24只,每个日龄阶段分为2组[分别饲喂常规饲粮(饲粮粗蛋白质水平为23%)和低蛋白质饲粮(饲粮粗蛋白质水平为21%)],每组6个重复,每个重复4或2只鸡。每期试验7 d,其中预试期4 d,正试期3 d。采用家禽12室联排开路式呼吸测热装置分别测定肉鸡11~14日龄、21~24日龄和35~38日龄呼吸数据。试验2:分别选择7、17和30日龄AA肉鸡各108只,每个日龄阶段分为3组,每组6个重复,每个重复6只鸡。3组肉鸡分别饲喂常规饲粮、低蛋白质饲粮和无氮饲粮,并分别于10、20和33日龄时开展屠宰试验,测定氨基酸标准回肠消化率。结果表明:1)与常规饲粮相比,低蛋白质饲粮对3个日龄阶段肉鸡生长性能均无显著影响(P>0.05),显著降低肉鸡21~24日龄氧气消耗量(P<0.05)。2)与常规饲粮相比,低蛋白质饲粮显著提高肉鸡11~14日龄代谢能/总能值(P<0.05);显著降低21~24日龄总产热、热增耗和蛋白质沉积能(P<0.05),显著提高净能/代谢能值(P<0.05);显著提高35~38日龄净能(P<0.05)。3)与常规饲粮相比,低蛋白质饲粮显著降低肉鸡7~10日龄丙氨酸和酪氨酸标准回肠消化率(P<0.05),显著提高组氨酸标准回肠消化率(P<0.05);显著提高17~20日龄甘氨酸、胱氨酸、酪氨酸、丝氨酸、苏氨酸、天冬氨酸和缬氨酸标准回肠消化率(P<0.05);对30~33日龄氨基酸标准回肠消化率无显著影响(P>0.05)。综上所述,与常规饲粮相比,低蛋白质饲粮会显著降低肉鸡21日龄后产热量,提高净能利用率;净能体系可以更有效判断饲粮蛋白质水平对肉鸡的影响,有利于精准测定肉鸡对低蛋白质饲粮的能量代谢参数并分析体内能量调控方向;在肠道发育完善后,肉鸡对低蛋白质饲粮的氨基酸标准回肠消化率低于常规饲粮。

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。

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。

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。

不同水平胍基乙酸对育成期母貂生长性能及营养物质表观消化率的影响

试验旨在研究胍基乙酸(GAA)对育成期短毛黑母貂生长性能、脏器指数、营养物质和氨基酸表观消化率的影响。选用65日龄体重相近的育成期短毛黑母貂60只,随机分为6组,每组10个重复,每个重复1只貂,单笼饲养。对照组饲喂基础日粮,试验组饲喂在基础日粮中分别添加200、400、600、800、1000 mg/kg GAA的日粮。预试期1周,正试期分Ⅰ期(1~5周)和Ⅱ期(6~10周)。结果表明:与对照组相比,①育成期母貂基础饲粮中添加600 mg/kg GAA可显著提高Ⅰ、Ⅱ期和全期平均日增重(ADG)(P<0.05),极显著降低Ⅰ、Ⅱ期和全期料重比(F/G)(P<0.01),极显著提高全期平均日采食量(ADFI)(P<0.01),添加1000 mg/kg GAA可极显著提高Ⅱ期ADFI(P<0.01);②添加200 mg/kg GAA可显著提高心脏指数(P<0.05),1000 mg/kg组全肠长度极显著提高(P<0.01);③添加400 mg/kg GAA可极显著提高Ⅰ期粗蛋白(CP)表观消化率(P<0.01),添加600 mg/kg GAA可显著提高Ⅱ期粗脂肪(EE)表观消化率(P<0.05),极显著提高Ⅱ期粗灰分(Ash)、钙(Ca)和磷(P)表观消化率(P<0.01),添加1000 mg/kg GAA可显著提高Ⅱ期CP表观消化率(P<0.05);④添加600 mg/kg GAA可显著提高Ⅰ期总氨基酸(TAA)、Ⅱ期谷氨酸(Glu)表观消化率(P<0.05),极显著提高Ⅰ期赖氨酸(Lys)、Ⅱ期TAA表观消化率(P<0.01),添加800 mg/kg GAA可显著提高Ⅰ期胱氨酸(Cys)、蛋氨酸(Met)和精氨酸(Arg),Ⅱ期Met和组氨酸(His)表观消化率(P<0.05),极显著提高Ⅰ期缬氨酸(Val)和His、Ⅱ期Lys和Arg表观消化率(P<0.01)。综合生长性能、脏器指数、营养物质和氨基酸表观消化率等指标,建议育成期Ⅰ期、Ⅱ期母貂基础饲粮中GAA的最适添加量为600~800 mg/kg。

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。

鱼类对乙醇梭菌蛋白中营养物质的表观消化率

试验旨在评价黑鲷(Acanthopagrus schlegelii)和建鲤(Cyprinus carpio var. Jian)对乙醇梭菌蛋白中干物质、粗蛋白、氨基酸、粗脂肪和总磷的表观消化率。试验饲料由70%的基础饲料和30%的乙醇梭菌蛋白组成,并添加0.1%的三氧化二钇(Y_(2)O_(3))作为指示剂。选取平均体重为(6.03±0.09) g的黑鲷360尾,分为两组,每组6个重复,每个重复30尾,两组分别饲喂基础饲料和试验饲料;选取平均体重为(45.00±0.50) g的建鲤180尾,分为两组,每组3个重复,每个重复30尾,两组分别饲喂基础饲料和试验饲料。结果表明,黑鲷对乙醇梭菌蛋白中干物质、粗蛋白、氨基酸、粗脂肪和总磷的表观消化率分为99.89%、100%、95.16%~100%、88.60%和100%;建鲤对乙醇梭菌蛋白中干物质、粗蛋白、氨基酸、粗脂肪和总磷的表观消化率分为78.68%、95.00%、96.12%~100%、52.26%和100%。总体而言,乙醇梭菌蛋白的粗蛋白和氨基酸的表观消化率均处在较高水平。由此可知,对黑鲷和建鲤而言,乙醇梭菌蛋白是较好的单细胞蛋白原料。

Prediction of protein and amino acid composition and digestibility in individual feedstuffs and mixed diets for pigs using near-infrared spectroscopy

Knowledge of the amounts and digestibility of amino acids in pig feedstuffs is essential for calculating the appropriate inclusion level in a complete diet.Wet chemical analysis and in vivo digestibility trials are time-consuming and costly and cannot be used for routine assessment.Near-infrared spectroscopy(NIRS)offers a rapid,cost effective and environmentally friendly method for evaluating feedstuffs.Calibrations models were developed using NIRS to predict the content of crude protein and 18 amino acids from a wide range of feedstuffs used in pig production(n=607).The samples ranged from single feed ingredients(containing amino acids from 0.3 to 129.8 g/kg of dry matter)to feed mixtures(containing amino acids from 1.2 to 53.2 g/kg of dry matter).The predictive ability of the calibrations was tested with an independent dataset(n=150)and with cross-validation.Furthermore,we compare these calibrations with calibrations developed on more narrowly defined groups of samples and with predictions from regression analysis of crude protein.The models were able to predict the concentrations of crude protein and 18 amino acids with good levels of precision and high coefficients of determination for calibration(RSQ^(CAL))from 0.91 to 0.99 and validation(RSQ^(VAL))from 0.87 to 0.97.Calibration models were able to predict all amino acids except tryptophan and valine with greater accuracy than those from protein regression.We also developed calibration models to predict the apparent ileal and total tract digestibility of protein and amino acids.With the exception of tryptophan,RSQ values(>0.7)and standard error of cross validation(SECV)values(<5%)were obtained for the digestibility of most of the amino acids.In conclusion,NIRS can be used to predict crude protein and amino acid concentrations from a wide range of single ingredients and feed mixtures used for pig diets without separate models for each feedstuff.The digestibility of protein and amino acids can be predicted with an acceptable accuracy to be useful in formulating pig diets.

Effects of dietary cellulose levels on the estimation of endogenous amino acid losses and amino acid digestibility for growing pigs

Two experiments were conducted to investigate the effects of dietary cellulose levels on the determination of the ileal endogenous losses(IEL) of amino acids(AA), apparent ileal digestibility(AID) and standardized ileal digestibility(SID) of AA in corn-soybean meal diets for growing pigs. In the first experiment, 28 pigs(BW, 45.1 ± 2.0 kg) that were fitted with simple T-cannulas at the distal ileum were fed 4 nitrogen-free diets consisting of 4 dietary cellulose levels(0, 3%, 6% and 9%) in a randomized complete block design. In the second experiment, 28 pigs(BW, 45.6 ± 2.0 kg) fitted with simple Tcannulas at the distal ileum were fed 4 corn-soybean meal diets consisting of 4 dietary cellulose levels(0,3%, 6% and 9%) in a randomized complete block design. There were 7 replicates per diet with 1 pig as a replicate in each treatment. Both experiments consisted of a 7-d adjustment period and a 2-d ileal digesta collection period on d 8 and 9. Chromic oxide was used as an indigestible marker to calculate IEL and digestibility of AA. The results showed that the IEL of AA for growing pigs was not influenced by dietary cellulose supplementation(P > 0.05). The AID of Thr, Ser, Glu, Cys, Ile, Tyr, Phe, Lys and His decreased with increasing cellulose supplementation levels for pigs fed corn-soybean meal diets(P < 0.05). The SID of Thr, Ser, Cys, Val, Ile, Tyr, Phe, Lys and His decreased with increasing cellulose supplementation levels in corn-soybean meal diets(P < 0.05). In summary, dietary cellulose levels had no effect on the estimation of IEL of AA for growing pigs. The AID and SID of most AA in corn-soybean meal diets decreased with increasing levels of dietary cellulose supplementation.

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。