Inositol hexaphosphate increases mucin loss from the digestive tract of ducks

The effects of different forms of inositol hexaphosphate (IP6, phytate) on mucin excretion from the digestive tract of ducks were investigated. Forty-eight ten-wk-old male ducks were grouped by weight into eight blocks of six cages with one bird per cage. On the first day of experimentation, birds received by intubation six dextrose-based diets arranged in a 2 × 3 factorial consisting of phytase (0 or 1000 units) and a form of IP6 (no IP6, free phytic acid or magnesium-potassium phytate). During the 54 h following feeding, excreta were continuously collected and frozen until analysed. The amount of mucin and amino acids, threonine, valine and tyrosine, in excreta increased in ducks fed with either magnesium-potassium phytate or free phytic acid. The increase in mucin excretion was more in birds fed with magnesium-potassium phytate than those fed with free phytic acid. The loss of arginine, isoleucine, leucine, lysine and phenylyalanine in excreta was reduced by the presence of microbial phytase. It is concluded that the form of IP6 fed to ducks affects the extent of mucin excretion and also the extent and nature of endogenous amino acid losses in the excreta. Supplementation with exogenous microbial phytase reduced some of the IP6 feeding-induced endogenous intestinal amino acid losses.     

Effect of dietary phytate and phytase on metabolic change of blood and intestinal mucosa in chickens

The objective of this study was to investigate the effect of dietary phytate and phytase on the metabolic parameters of lipid, protein, enzyme, electrolyte in the blood or intestinal mucosa of broiler chickens. Diets containing phytate phosphorus (0.22% or 0.44%) with phytase supplementation (0, 500 or 1000 U/kg) were administrated to 504 Cobb chicks for 4 weeks. Results showed that the serum concentrations of total cholesterol (T‐CHO), albumin, albumin/globulin, total superoxide dismutase (T‐SOD), total antioxidant capacity (T‐AOC) and glutamic pyruvic transaminase (GPT) were decreased by 9–41% in high phytate diets (p < 0.05) and the concentrations of blood P, K, Fe, Cu, Zn and Mg were decreased by 4–14% for birds fed high phytate diets (p < 0.05), whereas inclusion of phytase compensated these adverse influences. In the duodenum, phytate decreased the level of T‐AOC by 13% (p < 0.05), whereas phytase increased the levels of T‐SOD, T‐AOC and alkaline phosphatase (ALP) by 9–16% (p < 0.05). Also, in the jejunum, diets with high phytate showed lower activity of T‐SOD, T‐AOC and glutamic oxaloacetic transaminase (GOT) (p < 0.05), and phytase increased T‐SOD, T‐AOC and ALP (p < 0.05). However, phytase decreased transaminase activity in the low phytate basal diets (p < 0.05). This study suggests that dietary phytate can adversely interfere with the metabolisms of lipid and protein, as well as the antioxidation of blood and intestinal cells, while phytase supplementation may compensate these effects for broiler chickens.     

麦类籽实中植酸酶的活性及体外降解植酸盐效果的研究

为评价不同麦类籽实中内源植酸酶的活性及其对外源植酸盐的降解能力,以植酸钠为底物,测定5种10个不同品种麦类籽实中植酸酶的活性;在37℃、pH 5.50的条件下,以300 U/kg的浓度加入从麦类籽实中提取的植酸酶,检测了对玉米、豆粕中植酸磷的释放效果。结果表明,燕麦、大麦(垦啤2号)、小麦(东农123)、小麦(东农973821)、小黑麦(5305)、小黑麦(92021)、小黑麦(96026)、小黑麦(8809)、胜利黑麦和黑麦(2号)籽实中植酸酶的活性分别为57.50、143.25、1048.06、725.22、1978.67、2201.65、1713.46、1406.49、5310.89 U/kg和3446.53 U/kg(风干基础);在上述条件下,反应8h,玉米、豆粕中的植酸磷分别释放71.92%和38.94%。     

Influence of phytate level on broiler performance and the efficacy of 2 microbial phytases from 0 to 21 days of age

Phytate is an antinutrient in animal feeds, reducing the availability and increasing the excretion of nutrients. Phytases are widely used to mitigate the negative influences of phytate. This trial was designed to compare the efficacy of 2 Escherichia coli-derived phytases on broiler performance and bone ash as influenced by dietary phytate level. A total of 1,024 Arbor Acres male broilers were used with 8 replicate pens of 16 birds/pen. Experimental diets were based on low available phosphorus (avP; 1.8 g/kg) with low (6.40 g/kg) or high (10.65 g/kg) phytate. The low-avP diets were then supplemented with mono-dicalcium phosphate to increase the avP level to 4.5 g/kg, 500 phytase units/kg of phytase A, or 500 phytase units/kg of phytase B to create 8 experimental diets. Feed intake, BW gain, FCR, and livability were influenced by a P source × phytase interaction. Feed intake, BW gain, and livability were reduced and FCR was higher in broilers fed low-avP diets, particularly in the presence of high phytate. Phytase A or phytase B improved feed intake, BW gain, and FCR, particularly in the high-phytate diet. However, broilers fed phytase A ate more and were heavier than broilers fed phytase B. Tibia ash was lowest in broilers fed the low-avP diet and highest in broilers fed the diet supplemented with mono-dicalcium phosphate. Phytase increased tibia ash, and broilers fed phytase A had an increase in tibia ash compared with broilers fed phytase B. In conclusion, high dietary phytate reduced broiler performance. Phytase A and phytase B improved bone ash and growth performance, especially in the high-phytate diets. However, phytase A was more efficacious than phytase B, regardless of the level of phytate.     

Non‐phytate phosphorus requirements and efficacy of a genetically engineered yeast phytase in male lingnan yellow broilers from 1 to 21 days of age

This experiment was conducted to investigate the requirement of non‐phytate phosphorus (nPP) and efficacy of a genetically engineered yeast phytase in performance and tibia characteristics by male Lingnan Yellow broilers from 1 to 21 days of age. A total of 2640 1‐day‐old male chicks were randomly allotted to one of 11 dietary treatments, which consisted of six replicate floor pens with 40 birds per pen. All treatments had the same levels of all nutrients except for phosphorus and phytase. The control group (treatment 1) was fed the basal diet without dicalcium phosphate or phytase supplementation. Dietary concentrations of nPP were 0.11%, 0.19%, 0.27%, 0.35%, 0.43%, 0.51% and 0.59% respectively for treatments 1, 2, 3, 4, 5, 6 and 7, through addition of dicalcium phosphate (chemistry grade) to the basal diet. Diets 8–11 were supplemented with a genetically engineered yeast phytase 250, 500, 750 U/kg and a commercial phytase product 500 U/kg in basal diet respectively. The results showed that 0.46% and 0.51% nPP were required for maximum body‐weight gain and optimum tibia development indicators respectively. However, 0.59% nPP had a negative effect on bird growth. The equivalency value of the genetically engineered yeast phytase was estimated to be 874 U/kg to liberate 0.1% nPP.     

Effects of supplementation of high-dosing Trichoderma reesei phytase in the corn-wheat-soybean meal-based diets on growth performance,nutrient digestibility,carcass traits,faecal gas emission,and meat quality in growing-finishing pigs

We conduct this study to investigate the effects of corn-wheat-soybean meal (SBM)-based diet supplemented with high-dosing Trichoderma reesei phytase on the growth performance, nutrient digestibility, carcass traits, faecal gas emission and meat quality in growing-finishing pigs (29.71–110.58 kg live weight; 70-day-old to 166-day-old). A total of 56 crossbred pigs [(Landrace × Yorkshire) × Duroc] were used in 96-day experiment with a completely randomized block design. The growing period was from day 0 to 42, and the finishing period was from day 43 to 96. Pigs were randomly allocated to one of two treatments with seven replicate pens and four pigs (two barrows and two gilts) per pen and fed corn-wheat-SBM-based nutrient adequate basal diet or the basal diet supplemented with 1500 FTU/kg diet Trichoderma reesei phytase. One phytase unit (FTU) was defined as the amount of enzyme that catalyses the release of one micromole phosphate from phytate per minute at 37°C and pH 5.5. Dietary supplement with Trichoderma reesei phytase had increased body weight on day 96 and average daily gain in days 0–96. Moreover, high apparent total tract digestibility (ATTD) of phosphorus (P) was observed in pigs fed with Trichoderma reesei phytase. However, the carcass traits, faecal gas emission and meat quality of pigs were unaffected by Trichoderma reesei phytase supplementation. In conclusion, supplementation of high-dosing Trichoderma reesei phytase (1500 FTU/kg diet) in the corn-wheat-SBM-based nutrient adequate basal diet increased body weight and the ATTD of P, while no adverse effects were observed on the production characteristics.     

Intrinsic phytase in hybrid rye increases the digestibility of phosphorus in corn and soybean meal in diets fed to growing pigs

An experiment was conducted to test the hypothesis that inclusion of hybrid rye in diets containing corn and soybean meal (SBM) without or with microbial phytase improves the apparent total tract digestibility (ATTD) and the standardized total tract digestibility (STTD) of P because of the intrinsic phytase activity in hybrid rye. Forty-eight growing barrows (initial body weight: 39.5 ± 7.7 kg) were allotted to six diets. A basal diet containing corn and SBM; a rye-based diet; and a diet containing corn, SBM, and rye were formulated. Each diet was formulated without and with microbial phytase (500 units/kg of diet) for a total of six diets. Fecal samples were collected for 4 d following a 5-d adaptation period according to the marker-to-marker procedure. Results indicated that no interactions between diets and concentration of phytase were observed for any of the response criteria measured. The ATTD and STTD of P and the ATTD of Ca differed (P < 0.05) among diets, but regardless of diet, the concentration of P in feces was reduced (P < 0.05) by adding microbial phytase to the diets. As a consequence, microbial phytase increased (P < 0.05) ATTD and STTD of P, and the ATTD of Ca was also increased (P < 0.05) by the use of microbial phytase. Measured values for the ATTD and STTD of P in the diets containing corn, SBM, and hybrid rye without or with phytase were greater (P < 0.05) than values that were predicted based on the ATTD and STTD of P for the corn–SBM and the hybrid rye diet. The observation that STTD predicted from the individual ingredients underestimated the STTD of P in the mixed diet indicates that the intrinsic phytase in hybrid rye resulted in increased digestibility of the P in the corn and SBM included in the corn–SBM–hybrid rye diet. In conclusion, microbial phytase increased the ATTD and STTD of P and the ATTD of Ca regardless of feed ingredients used in diets fed to pigs. In addition, the intrinsic phytase from hybrid rye increased the ATTD and STTD of P in corn and SBM.     

Effects of supplementing freeze-dried Mitsuokella jalaludinii phytase on the growth performance and gut microbial diversity of broiler chickens

Inclusion of phytase in animal feedstuff is a common practice to enhance nutrients availability. However, little is known about the effects of phytase supplementation on the microbial ecology of the gastrointestinal tract. In this study, freeze-dried Mitsuokella jalaludinii phytase (MJ) was evaluated in a feeding trial with broilers fed a low available phosphorus (aP) diet. A total of 180 male broiler chicks (day-old Cobb) were assigned into three dietary treatments: Control fed with 0.4% (w/w) of available phosphorus (aP); Group T1 fed low aP [0.2% (w/w)] supplemented with MJ; and T2 fed low aP and deactivated MJ. The source of readily available P, dicalcium phosphate (DCP), was removed from low aP diet, whereby additional limestone was provided to replace the amount of Ca normally found in DCP. For each treatment, 4 replicate pens were used, where each pen consisted of 15 animals. The animals' energy intake and caecal bacterial community were monitored weekly for up to 3 weeks. The apparent metabolizable energy (AME) and apparent digestibility of dry matter (ADDM) of broilers fed with different diets were determined. In addition, the caecal microbial diversities of broilers were assessed using high-throughput next-generation sequencing targeting the V3-V4 region of bacterial 16S rRNA. The results showed that broilers fed with T1 diet have better feed conversion ratio (FCR) when compared to the Control (p < .05) and T2 diets (p < .05), demonstrating the efficiency of MJ as a supplement to low aP diet. Nevertheless, MJ did not significantly affect the microbial population and diversity in broilers' caeca, which mainly consists of members from Bacteroidetes, Firmicutes, and Proteobacteria. Regardless, significant variations in the caecal bacterial composition were observed over time, probably due to succession as the broilers aged. This is the first reported study on the effect of MJ on the microbial diversity of broiler's caeca.     

Effect of an organic acid blend and phytase added to a rapeseed cake‐containing diet on performance,intestinal morphology,caecal microflora activity and thyroid status of broiler chickens

The experiment was carried out on 96 female broilers, allocated to eight groups of 12 birds kept in individual cages. Two basal wheat‐ and soyabean meal‐based diets containing 150 g/kg of rapeseed expeller cake were formulated, differing in the level of P: 7.1 g/kg in diet H or 5.9 g/kg in diet L. Rapeseed cake supplied 3.15 μmol alkenyl glucosinolates per gram of diet. The eight treatments were: basal diets only, basal diets + phytase (1000 U/kg), basal diets + organic acid blend (OA, 6 g/kg), or basal diets + both additives. Diets were fed from day 8 to 28 of life. The results showed that the lower dietary P content and OA supplementation did not significantly affect feed intake or BWG, while both increased (p < 0.001) after phytase supplementation. Tibia ash content as well as tibia ultimate strength were lower (p < 0.001) in birds fed diets L compared with diets H, and increased (p < 0.01) with phytase supplementation of diet L, while OA had no influence on either parameter. Dietary P levels and OA supplementation had no influence on the pH of gut digesta, but the pH of jejunal digesta increased following phytase supplementation (p < 0.01). Morphological measurements of the small intestinal mucosa of chicks indicated that OA added to diet L depressed villi height (p < 0.001) and crypt depth (p < 0.001); both parameters increased after phytase supplementation (p < 0.01). The lower total SCFA as well as acetic, propionic and butyric acid concentrations in caecal digesta indicated lower activity of caecal microflora in birds fed diets L compared with H. OA supplementation had no influence, while phytase supplementation increased the concentration of acetic acid in caecal digesta. Supplementation of diets with either phytase or OA increased thyroid weight by 16% (p < 0.01) and 11% (p < 0.05) respectively. The increase in thyroid weight because of phytase supplementation was greater at the lower dietary P level, and the greatest when both phytase and OA were added to the diet.     

纳米载铜蒙脱石对断奶仔猪生长、肠道菌群及其肠黏膜形态的影响

选用128头健康“杜长大”三元杂交断奶仔猪,随机分为对照组、CuSO4组、纳米蒙脱石(MMT)组和MMT-Cu组,分别饲喂基础日粮(对照组)、基础日粮+78 mg/kg Cu2+(CuSO4.5H2O,相当于MMT-Cu中Cu2+的量)、基础日粮+2.0 g/kgMMT、基础日粮+2.0 g/kgMMT-Cu。结果表明,与对照组相比,MMT-Cu组能显著提高(P<0.05)断奶仔猪的平均日增重、饲料转化效率及小肠绒毛高度、绒毛高度与隐窝深度的比值,显著降低(P<0.05)腹泻率及小肠、结肠内容物中大肠杆菌和沙门氏菌的数量;而MMT组也显著降低(P<0.05)仔猪腹泻率,提高(P<0.05)小肠绒毛高度和绒毛高度与隐窝深度的比值。与MMT组或CuSO4组相比,MMT-Cu组能显著(P<0.05)提高断奶仔猪的平均日增重和饲料转化效率(P<0.05),显著降低了(P<0.05)小肠和结肠内容物中大肠杆菌和沙门氏菌的数量。     

旋转磁场对饲用植酸酶活性影响的试验研究

试验采用来自国内外不同企业生产的4种植酸酶试剂,常规条件下分别在旋转磁场中处理0、5、10、15、20、25min,用钒钼磷显色法检测酶活性,试验结果表明:其中3种酶活性受到旋转磁场影响不显著,而另一种酶活性却降低到原活性的50%左右,其原因可能是由于磁场改变了植酸酶的空间结构,从而影响其活性。     

早期断奶仔猪肠黏膜的营养调控

肠黏膜的发育与成熟状况是制约幼畜快速生长的关键因素。早期断奶仔猪肠黏膜免疫力较低,容易遭受饲粮抗原的刺激而引起肠黏膜过敏性损伤,诱发仔猪断奶后腹泻。通过肠黏膜营养调控技术,补充肠黏膜能量营养, 促进肠黏膜的发育与成熟,修补断奶引起的肠黏膜损伤,可以从根本上减轻仔猪断奶后腹泻的发生。本文对早期断奶引起的肠黏膜形态变化以及有利于修复受损伤肠黏膜的营养物和调控因子进行了综述。     

Dietary phytase increases the true absorption and endogenous fecal excretion of zinc in growing pigs given a corn-soybean meal based diet

We investigated the effect of dietary phytase on the true absorption and endogenous fecal excretion of zinc (Zn) using ⁶⁷Zn in growing pigs given a corn-soybean meal based diet. Ten crossbred barrows were fed the control diet containing 90-mg/kg Zn, 2.3-g/kg phytate-phosphorus and 3.7-g/kg non-phytate-phosphorus or the phytase diet containing similar amounts of Zn and phytate-phosphorus, and 1.4-g/kg non-phytate-phosphorus with 750-PU/kg phytase for 12 h/day. On day 6, the pigs were given 200 g of the corresponding diet labeled by ⁶⁷Zn for 2 h. We measured feed intake, fecal Zn concentration and ⁶⁷Zn abundance for the determination of apparent absorption, true absorption and endogenous fecal excretion of Zn. Although the apparent absorption of Zn did not significantly differ between the dietary groups, the phytase group had significantly more ( P  < 0.05) true absorption of Zn than the control group. The endogenous fecal excretion of Zn tended to be more ( P  = 0.07) in the phytase group than in the control group. These results suggest that dietary phytase improves Zn bioavailability through increasing the true absorption of Zn in growing pigs, which results in stimulating the endogenous fecal excretion of Zn when dietary Zn satisfies its requirement.     

猪小肠黏膜加工下脚料酶解工艺的研究

以猪小肠黏膜提取肝素后的下脚料为原料,利用木瓜蛋白酶对肠黏膜蛋白质进行水解。在单因素分析的基础上采用正交实验对水解条件进行优化,得出最适酶解条件为:酶加量3000 U/g底物蛋白,底物浓度6%,pH值7.5,温度45℃,水解时间3h。在此条件下的水解度为20.63%。     

一种新型肠粘膜保护剂——载铜蒙脱石对肠粘膜屏障功能影响的研究

以蒙脱石（MMT）为原料，通过阳离子交换反应合成载铜蒙脱石（MMT-Cu）。为探讨载铜蒙脱石对肠粘膜屏障功能的影响，采用体外培养的单层Caco-2细胞模型为研究对象，以细菌易位数量和肠绒毛损伤程度做为指标进行研究。结果表明：MMT-Cu可明显减少（P〈0．01）E．coilK88、S．choleraesuis侵入到Caco-2细胞内的数量，与对照组相比，下降了2logCFU／mL～3log CFU／mL；并能显著降低（P〈0．01）LDH的释放量。扫描电子显微镜下观察可见，加入MMT-Cu一段时间后，当E．coil K88和S．choleraesuis粘附Caco-2细胞时，微绒毛依旧排列整齐、致密，可见肠上皮细胞保持完好。结果表明，MMT-Cu对肠粘膜具有屏障作用，可作为一种消化道粘膜保护剂。     

6-羟多巴胺对小鼠体重及其小肠黏膜结构的影响

采用组织学和图像分析技术，研究了小鼠经腹腔注射交感神经损毁剂6-羟多巴胺后小鼠体重和小肠绒毛长度、V／C比值、绒毛宽度以及黏膜厚度的变化。结果表明，注射6-羟多巴胺组与对照组小鼠相比，体重下降（约3．4％）；小肠绒毛变短（5．6％～19．4％），V／C比值减少（0．88％～24．1％），绒毛变窄（8．8％～24．7％）、黏膜厚度变薄（4．4％～16．9％），其中空肠的绒毛长度和黏膜厚度减少较明显，而十二指肠和回肠的V／C比值和绒毛宽度减少较明显。提示交感神经的活动可影响小肠的黏膜结构，从而影响肠道的消化吸收功能。     

一株牦牛源屎肠球菌对小鼠肠道微生物、形态和免疫功能的影响

为研究牦牛肠黏膜源屎肠球菌G2对健康小鼠肠道微生物、形态和免疫功能的影响,试验设置对照组(CON)、热灭活菌组(EHK)、活菌组(ENT)3个处理组,每组8只C57BL/6小鼠,共计24只。CON组、EHK组、ENT组于正式试验期第1、2、4、6天按0.1 mL/只分别灌胃M17培养基、热灭活菌液和活菌菌液,灌胃前无菌收集小鼠粪便进行乳酸菌总菌计数,第8天处死小鼠取样。结果表明:ENT组乳酸菌总菌数量在第3、5天显著大于CON组与EHK组(P <0.05);各组小鼠结肠病理学评分无显著差异,但ENT组隐窝深度显著高于CON组与EHK组(P <0.05);各组间肠黏膜免疫因子Reg3β、Reg3γ和MUC2基因mRNA表达量差异不显著,TNF-α表达量ENT组显著低于CON组(P <0.05)。综上可知,牦牛源屎肠球菌G2可能为一种肠道过路菌,能在短时间内提高肠道乳酸菌的总数,一定程度上具有改善肠道形态和促进肠道健康的作用。     

肠道微生物影响单胃动物免疫的分子机理研究进展

动物胃肠道中分布着复杂而庞大的微生物,被称为动物机体的另一个器官,在诸多方面影响着宿主机体的健康和发育,尤其在宿主免疫调节过程中发挥着至关重要的作用.不同的肠道微生物如厚壁菌门、拟杆菌门、变形菌门等通过多种机制调控着宿主免疫功能.肠道微生物代谢产物,如短链脂肪酸(SCFAs)、多胺类、芳香烃受体(AHR)配体等及其自身...     

Dietary shifts affect the gastrointestinal microflora of the giant panda (Ailuropoda melanoleuca)

Giant pandas exhibit seasonal changes in bamboo plant part preference. The influences on the gastrointestinal tracts (GIT) microbial populations were evaluated during a 14‐month period for a pair of adult male and female giant pandas housed at the Memphis Zoo using traditional culturing methods to enumerate eight bacterial groups (total anaerobes, total aerobes (TAR), streptococci (STR), total enterics, Escherichia coli, Bacteroides spp., lactobacilli and Clostridium spp.). Both the male and female pandas altered bamboo consumption behaviours, with a sharp decrease in leaf preference in April 2010 and returning to high levels of leaf preference from June to October, corresponding to significant shifts in the densities of TAR, STR, and lactobacilli and Bacteroides spp. These findings indicate seasonal changes in food preference affect the assemblages of microbial populations within the GIT of the giant panda and contribute to a better understanding of the importance of bamboo in this species’ foraging strategy.