Amino acid and mineral digestibility,bone ash,and plasma inositol is increased by including microbial phytase in diets for growing pigs

Background The effect of microbial phytase on amino acid and energy digestibility is not consistent in pigs,which may be related to the phytase dosage or the adaptation length to the diet.Therefore,an experiment was conducted to test the hypotheses that increasing dietary phytase after an 18-day adaptation period:1)increases nutrient and energy digestibility;2)increases plasma P,plasma inositol,and bone ash of young pigs;and 3)demonstrates that maximum phytate degradation requires more phytase than maximum P digestibility.Results Data indicated that increasing inclusion of phytase[0,250,500,1,000,2,000,and 4,000 phytase units(FTU)/kg feed]in corn-soybean meal-based diets increased apparent ileal digestibility(AID)of Trp(quadratic;P<0.05),and of Lys and Thr(linear;P<0.05),and tended to increase AID of Met(linear;P<0.10).Increasing dietary phytase also increased AID and apparent total tract digestibility(ATTD)of Ca and P(quadratic;P<0.05)and increased ATTD of K and Na(linear;P<0.05),but phytase did not influence the ATTD of Mg or gross energy.Concentrations of plasma P and bone ash increased(quadratic;P<0.05),and plasma inositol also increased(linear;P<0.05)with increasing inclusion of phytase.Reduced concentrations of inositol phosphate(IP)6 and IP5(quadratic;P<0.05),reduced IP4 and IP3(linear;P<0.05),but increased inositol concentrations(linear;P<0.05)were observed in ileal digesta as dietary phytase increased.The ATTD of P was maximized if at least 1,200 FTU/kg were used,whereas more than 4,000 FTU/kg were needed to maximize inositol release.Conclusions Increasing dietary levels of phytase after an 18-day adaptation period increased phytate and IP ester degradation and inositol release in the small intestine.Consequently,increasing dietary phytase resulted in improved digestibility of Ca,P,K,Na,and the first 4 limiting amino acids,and in increased concentrations of bone ash and plasma P and inositol.In a corn-soybean meal diet,maximum inositol release requires approximately 3,200 FTU/kg more phytase than that required for maximum P digestibility.

Effects of supplemental xylanase and xylooligosaccharides on production performance and gut health variables of broiler chickens

Background:This study evaluated the effects of supplemental xylanase and xylooligosaccharides(XOS)in a cornsoybean meal(SBM)-based diet on growth performance and intestinal health of broilers.A total of 288 day-old chicks(Cobb 500)were allocated to 36 floor pens(8 birds/pen)equally in 9 dietary treatments in a 3×3 factorial arrangement.The treatments were combinations of 3 levels of xylanase(0,0.005% and 0.01% Econase XT)and 3 levels of prebiotics(0,0.005% and 0.01% XOS)added to basal mash diets formulated in three phases(starter,d 0-14;grower,d 15-28;finisher,d 29-42).The feed intake and body weights were recorded weekly.On d 42,ileal sections were collected for histomorphometric and gene expression analysis,and cecal content was collected for determining short-chain fatty acids(SCFA)and microbiota.Results:Xylanase linearly(P<0.01)increased the average daily gain(ADG)in both the finisher and total period and the final body weight gain(FBWG,2940&2932 vs.2760 g)of broilers.XOS did not significantly increase either ADG or FBWG(P>0.05).Supplemental xylanase and XOS did not affect average daily feed intake and feed conversion ratio(P>0.05).Xylanase and XOS did not change villus height(VH)or crypt depth(CD)ratio(P>0.05).However,xylanase exhibited a trend(P=0.097)on VH:CD ratio.The inclusion of 0.01%XOS without xylanase increased the level of IL-10(a marker of anti-inflammatory cytokine)and IL-4(a T-cell differentiation cytokine)genes compared with control(P<0.05).The acetate production was increased by xylanase(P<0.01)and XOS(P<0.05)without an additive effect.Xylanase increased total SCFA(P<0.01)while XOS had a tendency to increase(P=0.052).Alpha and beta diversity of microbiota among treatments were not different(P>0.05).However,the mean proportion of family Ruminococcaceae was increased by the supplemental 0.01% xylanase(P<0.01).Conclusion:It can be concluded that XOS can enhance cecal fermentation,while xylanase can increase the body weight gain along with the fermentation metabolites in the ceca of broilers fed the corn-SBM-based diet but the effects may not always translate into an improved mucosal absorptive capacity and a better feed efficiency.

Influence of the concentration of dietary digestible calcium on growth performance,bone mineralization, plasma calcium, and abundance of genes involved in intestinal absorption of calcium in pigs from 11 to 22 kg fed diets with different concentrations of

Background: A 21-day experiment was conducted to test the hypothesis that Ca requirements to maximize growth performance expressed as the standardized total tract digestible(STTD) Ca to STTD P ratio is less than 1.40:1. The second hypothesis was that increasing dietary Ca increases plasma Ca concentration and downregulates abundance of genes related to Ca absorption(TRPV6, S100 G, and ATP2 B1) in the duodenum, and tight junction proteins(OCLN, CLDN1, and ZO1) in the duodenum and ileum.Methods: Twenty corn-soybean meal diets were formulated using a 4 × 5 factorial design with diets containing 0.16%, 0.33%, 0.42%, or 0.50% STTD P, and 0.14%, 0.29%, 0.44%, 0.59%, or 0.74% STTD Ca. Six hundred and forty pigs(initial weight: 11.1 ± 1.4 kg) were allotted to 20 diets and 5 blocks in a randomized complete block design. On day21, weights of pigs and feed left in feeders were recorded and blood, duodenal tissue, ileal mucosa, and the right femur were collected from 1 pig per pen. Abundance of m RNA was determined in duodenal and ileal tissue via quantitative RT-PCR. Data were analyzed using a response surface model.Results: The predicted maximum ADG(614 g), G:F(0.65), and bone ash(11.68 g) was obtained at STTD Ca:STTD P ratios of 1.39:1, 1.25:1, and 1.66:1, respectively, when STTD P was provided at the requirement(0.33%). If dietary STTD P was below the requirement, increasing dietary Ca resulted in reduced(P < 0.05) ADG and G:F. However, if dietary STTD P was above the requirement, negative effects(P < 0.05) on ADG and G:F of increasing STTD Ca were observed only if dietary STTD Ca exceeded 0.6%. Plasma Ca concentration was positively affected by STTD Ca over the range studied(quadratic, P < 0.01) and negatively affected by increasing STTD P(linear, P < 0.01). There was a linear negative effect(P < 0.05) of STTD Ca on the abundance of S100 G, TRPV6, OCLN, and ZO1 in duodenum, and CLDN and ZO1 in ileum.Conclusions: The STTD Ca:STTD P ratio needed to maximize growth performance of 11-to 25-kg pigs is less than1.40:1, if P is at the estimated requirement. Increasing dietary Ca reduces transcellular absorption of Ca and increases paracellular absorption of Ca.

Stimbiotic supplementation modulated intestinal inflammatory response and improved broilers performance in an experimentally-induced necrotic enteritis infection model

Background:Two experiments were conducted to establish an optimal NE challenge model and evaluate the efficacy of stimbiotic(STB)supplementation in necrotic enteritis(NE)challenged broilers.In Exp.1,a total of 120 Arbor Acres(AA)broilers(45.0±0.21 g)were randomly assigned to 6 treatments in a 3×2 factorial arrangement.Vaccine treatments included non-challenge(0),×10 the recommended dose(×10)or×20 the recommended dose(×20)by the manufacturer.Clostridium perfringens(CP)treatments were non-challenge(No)or 3 mL of 2.2×10^(7)CFU CP challenge(Yes).In Exp.2,a total of 72 AA broilers(40.17±0.27 g)were randomly assigned to 6 treatments in a 3×2 factorial arrangement.Dietary treatments included non-additive(CON),100 mg/kg STB(STB)and 100 mg/kg STB on top of a typical commercial blend including an essential oil,probiotics,and enzyme(CB).Challenge treatments included non-NE challenge(No)and NE challenge(Yes)as established in Exp.1.Results:In Exp.1,CP and vaccine challenge decreased(P<0.05)body weight(BW),body weight gain(BWG)and feed intake(FI),and increased(P<0.05)the number of broilers with diarrhea and intestinal lesions.The oral administration of×20 recommended dose of vaccines coupled with 3 mL of 2.2×10^(7)CFU CP resulted in(P<0.01)a significantly increased incidence of wet litter and intestinal lesions.Thus,this treatment was chosen as the challenge model for the successful inducement of NE in Exp.2.In Exp.2,the NE challenge negatively affected(P<0.01)growth performance,ileal morphology,immunoglobulin contents in blood,caecal microbiota in the caecum,footpad dermatitis,intestinal lesion scores,tumour necrosis factor(TNF-α)and endotoxin in the serum compared with the non-NE challenged birds.The supplementation of STB and CB in diets enhanced(P<0.05)growth performance,intestinal microbiota,and blood profiles by stimulating ileal morphology(VH and VH:CD)and propionate production in the cecum,and there were no differences in measured variables between STB and CB supplemented birds.Conclusion:Overall,these results indicate that STB supplementation was able to reduce the inflammatory response and improve the performance of NE challenged birds,and the supplementation of STB alone was as effective as a typical commercial blend containing a number of other additives.

木聚糖酶和寡糖复合物对蛋鸡生产性能、蛋品质和血清免疫指标的影响

试验旨在研究饲粮中添加木聚糖酶和寡糖复合物对蛋鸡生产性能、蛋品质、食糜黏度和血清免疫指标的影响。试验选取42周龄的海兰褐蛋鸡450只,随机分为5组,每组6个重复,每个重复15只鸡,分别饲喂基础饲粮(对照组)、在基础饲粮中分别添加25(Ⅰ组)、50(Ⅱ组)、75 g/t(Ⅲ组)和100 g/t(Ⅳ组)木聚糖酶和寡糖复合物的试验饲粮。预试期7 d,正试期56 d。结果表明:①与对照组相比,饲粮添加木聚糖酶和寡糖复合物对蛋鸡的生产性能和蛋品质无显著影响(P>0.05);②Ⅳ组能显著降低蛋鸡十二指肠的pH(P<0.05),Ⅱ、Ⅲ组和Ⅳ组能显著降低蛋鸡十二指肠和空肠食糜的黏度(P<0.05);③饲粮添加木聚糖酶和寡糖复合物能提高蛋鸡血清中免疫球蛋白A(IgA)、免疫球蛋白G(IgG)和免疫球蛋白M(IgM)的含量。综上所述,饲粮添加100 g/t的木聚糖酶和寡糖复合物能降低蛋鸡小肠食糜的黏度和pH,增强机体的免疫机能。

高剂量植酸酶的关键特性

随着市面上饲用植酸酶类酶制剂数量的不断增多,这些植酸酶的特性多样性也在不断扩大。尽管植酸酶在正在研究与开发的产品中表现出了积极的作用,但是上述特性上的多样性使得直接进行性能的比较变得非常困难。这一挑战在对超剂量使用植酸酶的效果进行评估时将变得更加艰难,

饲用木聚糖酶制剂的体外评价技术研究

试验旨在研究木聚糖酶对蛋白酶的耐受性、对饲料还原糖含量及饲料能量和粗蛋白消化率的影响,以期建立木聚糖酶体外评价的方法。采集不同厂家的5种木聚糖酶制剂,经胃蛋白酶和胰蛋白酶两步反应后,测定木聚糖酶的酶活留存率,以一定的比例在猪配合饲料中添加木聚糖酶,保证饲料中酶活性相同,采用仿生消化系统测定粗蛋白和能量的消化率,同时模拟胃肠道p H值测定饲料中还原糖含量。结果表明:通过胃蛋白酶和胰蛋白酶的孵育后,5种木聚糖酶留存率差异显著(P<0.05),说明不同木聚糖酶对蛋白酶的耐受性不同。但饲料中添加5种不同的木聚糖酶制剂,对饲料能量和粗蛋白消化率及还原糖含量均没有显著影响(P>0.05)。因此,在试验条件下,两步酶解法对木聚糖酶留存率影响显著,可以作为木聚糖酶质量评价的参考;但是采用仿生消化系统测定饲料中能量和粗蛋白的消化率以及还原糖的含量,来评价木聚糖酶的生物学效应,还需要进一步通过动物试验进行验证。

如何评价酶制剂在饲料行业中的应用效果

饲用酶制剂的应用在畜牧行业中已非常普遍,但由于市场上酶制剂产品种类繁多,在选择和应用过程中,给使用者带来很多困扰。本文旨在探讨酶制剂在饲料应用中的几种评估方法的特点(包括常规酶活检测、酶制剂的基本特性、酶制剂的稳定性、应用效果试验等),以及如何构建评价体系,望对使用者具有一定的借鉴性。

电解质平衡对热应激状态下鸡生产性能的改善

现代肉鸡的高生长速率使得它们对多种代谢问题如酸碱平衡等的敏感性和易感性增加。其中引发酸碱失衡的一个主要原因是热应激,当相对空气湿度以及环境温度超过了舒适范围就会引起热应激,热应激会阻碍热量的散失,使鸡的体温上升,并影响其生产性能。

Sow performance in response to natural betaine fed during lactation and post-weaning during summer and non-summer months

Background: Two studies were conducted to evaluate the effects of dietary natural betaine on sow reproductive performance during summer(Exp. 1) and non-summer months(Exp. 2). Treatments were designed as a 2 × 2 factorial arrangement with factors including dietary betaine(0 or 0.2%) and period of supplementation(lactation or post-weaning until 35 days post-insemination). In Exp. 1, 322 and 327 sows and in Exp. 2, 300 and 327 sows representing young(parity 1 and 2) and mature(parity 3 to 6) sows, respectively, were used.Results: In Exp. 1, supplementation of betaine during lactation increased sow body weight losses(-11.95 vs.-14.63 kg;P = 0.024), reduced feed intake(4.12 vs. 4.28 kg/d;P = 0.052), and tended to reduce percentage of no-value pigs(P = 0.071). Betaine fed post-weaning reduced weaning-to-estrus interval(5.75 vs. 6.68 days;P = 0.054) and farrowing rate(86.74% vs. 91.36%;P = 0.060), regardless of parity group. Post-hoc analysis with sows clustered into 3 parity groups(1, 2 and 3, and 4+) indicated that betaine fed in lactation to parity 4+ sows(P = 0.026) and betaine fed post-weaning to parity 1 sows increased the number of pigs born in the subsequent cycle(P ≤ 0.05). In Exp. 2, betaine fed during lactation tended to reduce the weaning-to-estrus interval(6.64 vs. 7.50 days;P = 0.077) and farrowing rate(88.23% vs.83.54%;P = 0.089), regardless of parity group. Feeding betaine post-weaning reduced number of pigs born(13.00 vs.13.64;P = 0.04) and pigs born alive(12.30 vs. 12.82;P = 0.075), regardless of parity group.Conclusions: Using 0.2% betaine during the non-summer months did not benefit sow performance. During the summer, betaine supplementation in lactation increased subsequent litter size in parity 4+ sows. Betaine fed during the post-weaning period reduced the wean-to-estrus interval and farrowing rate, increased total number of pigs born for parity 1 sows and reduced total number of pigs born to parity 4+ sows. Further research is needed to determine if the detrimental effects on feed intake and farrowing rate may be correlated and depend on dietary betaine level.

重新审视饲料生产过程中蛋白质原料的评价方法

蛋白质原料是动物饲料的重要组成部分,有效评价蛋白质原料质量的优劣具有重要意义。活性赖氨酸是热损伤蛋白质原料质量最有效的评价指标,通过近红外光谱技术构建定标模型能够快速地测定活性赖氨酸含量,从而实现蛋白质原料优劣的快速评价。

重新认识酶制剂在家禽生产中的作用

过去25年来,大量研究报道了外源酶在单胃动物饲料中的应用。人们发现商品化植酸酶的使用效果与实验室结果并非完全一致。其中,很多研究认为植酸酶的应用与肉鸡垫料潮湿有关。解决的重点是通过改变日粮的成分,添加植酸酶来减少肉鸡垫料潮湿的发生。早期文献中提及的非淀粉多糖酶在体内的作用机制随着实践的检验，很多内容逐渐被证明不正确。尽管这些新的认识在商业化应用中取得的效果并非很明显，但随着新的产品的开发和应用，人们会慢慢接受。本文主要针对植酸酶和非淀粉多糖酶的应用进行阐述。

金霉素对肉鸡生产性能及腹脂沉积的影响研究

抗生素的使用提高了畜禽生产性能,同时也存在食品药物残留、耐药性产生、动物免疫功能下降等问题,甚至威胁人类的身体健康。国家法规对使用抗生素的限制性与规范性逐步开展,抗生素的替代品研究逐渐成为研究和应用热点。试验中旨在分析金霉素对肉鸡生产性能和屠宰性能的影响。试验选用1日龄AA雏公鸡进行肉鸡饲养试验,饲粮中添加金霉素,以未添加组为对照。结果表明,饲粮中添加金霉素有效含量为50 mg/kg时,可以显著提高肉鸡的活体重(P<0.05);日均采食量、屠体重、半净膛重、全净膛重、腿肌重、胸肌重和腹脂重等绝对重量指标也有所提高,但均差异不显著(P>0.05)。同时,添加组的屠体率显著降低(P<0.05),而腹脂率显著升高(P<0.05);其他相对重量指标降低或相等,差异不显著(P>0.05)。进一步的研究发现,金霉素(有效含量为50 mg/kg)添加组个体的血液中甘油三酯和胆固醇的含量显著升高,并且腹脂脂肪组织中的相关脂肪合成的相关基因表达显著上调(P<0.05或P<0.01)。结论,饲料中添加金霉素可以促进肉鸡生长,显著提高活体重,但是增加了肉鸡的腹脂沉积,导致了成鸡屠体率显著下降及其他屠宰性状的降低。

甜菜碱对猪生产性能的积极作用

甜菜碱是一种饲料添加剂,具有渗透调节能力和甲基供体的特性。在仔猪和肥育猪日粮中添加甜菜碱,不仅可以提高猪的生长性能,改善胴体特性,还可以降低日粮成本,提高养猪生产的经济效益。甜菜碱是存在于动物、细菌和植物原料中的一种天然成分。由于其具有渗透能力(能够保持水分子),通过累积可以调控盐的浓度和/或温度的变化。

低聚木糖和木聚糖酶可提高猪的生产性能

鉴于木聚糖酶能够间接提高仔猪的存活率和饲料转化率,美国许多养猪生产者正在饲料中添加该酶制剂。本文详细介绍了木聚糖酶的作用方式。

肠道微生物菌群管理--猪营养学发展的下一个大跨越

在过去12个月的各种会议中，肠道健康及其微生物菌群是最热门的议题。有机会可以更好地理解肠道健康、微生物菌群和猪健康之间的关系是非常令人兴奋的，且可以为未来进一步精心调控猪营养提供了巨大的潜力。

外源酶制剂的潜在营养价值及其在实际生产中的应用

在实际应用中,酶制剂的使用通常与潜在营养价值的应用密切相关,以实现预期效果这些潜在营养价值可采用不同的方法进行测定,但在多数情况下采用消化率和性能试验来测定。然而,每一种方法都有其局限性,特别是进行独立消化试验时,这种方法容易忽视摄食和吸收后的效应。同时,饲用酶的效果在很大程度上受环境、日粮以及养殖等相关因素的影响。因此,商业营养师应考虑生成营养潜在营养价值的分析条件与酶的使用条件之间的差异。在应用中,如果因为原料限制(如最低脂肪浓度)而无法减少昂贵、营养丰富的原料的使用,那么应用酶制剂的潜在营养价值不一定会如预期那样降低成本。此外,大多数酶都以固定添加量进行配制,这限制了其应用价值,因为大多数酶倾向于以对数剂量;线性营养释放关系来释放营养物质。有些方法会考虑到这一效应,并且能够使用酶制剂实现真正的最低配方成本最后,通常一种商业饲料可使用3种酶制剂,每种酶都有相应的能量潜在营养价值。虽然它们体现潜在营养价值的机制可能有所不同,但在实际应用之前我们需确保其潜在营养价值是真实可叠加的。

Reduced-particle size wheat bran and endoxylanase supplementation in broiler feed affect arabinoxylan hydrolysis and fermentation with broiler age differently

Since the caecal microbiota of young broilers are not yet able to ferment the dietary fibre(DF)fraction of the feed to a large extent,increasing the accessibility of DF substrates along the gastrointestinal tract is crucial to benefit from the health stimulating metabolic end-products(e.g.butyric acid)generated upon microbial DF fermentation.Therefore,the present study aimed to evaluate the potential of reduced-particle size wheat bran(RPS-WB)and endoxylanases as feed additives to stimulate arabinoxylan(AX)hydrolysis and fermentation along the hindgut of young broilers.To this end,RPS-WB and endoxylanase supplementation were evaluated in a 2×2 factorial design using a total of 256 male 1-d-old chicks(Ross 308).Broilers were assigned to 4 dietary treatments:a basal wheat-based diet with(1)no feed additives(control,CTRL),(2)an endoxylanase(XYL;Econase XT 25 at 0.10 g/kg diet),(3)1%wheat bran with an average reduced particle size of 297μm(RPS-WB)and(4)an endoxylanase and 1%RPS-WB(RPS-WB+XYL).Each dietary treatment was replicated 8 times and on d 10 and 28,respectively,24 and 16 broilers per treatment group were euthanised to analyse AX degradation,short-chain fatty acid production and digesta viscosity in the ileum and caecum.Broilers receiving XYL in their diet showed increased AX solubilisation and fermentation at both d 10 and 28 compared to the CTRL group(P<0.05).Adding RPS-WB to the diet stimulated wheat AX utilisation by the primary AX degraders in the caecum at 10 d of age compared to the CTRL group,as observed by the high AX digestibility coefficient for the RPS-WB supplemented group at this young age(P<0.05).At 28 d,RPS-WB supplementation lowered body-weight gains but increased butyric acid concentrations compared to the XYL and CTRL group(P<0.05).Although no synergistic effect for RPS-WB+XYL broilers was observed for AX hydrolysis and fermentation,these findings suggest that both additives can raise a dual benefit to the broiler as a butyrogenic effect and improved AX fermentation along the ileum and caecum were observed throughout the broiler's life.

木聚糖酶和玉米对肉仔鸡生长性能和表观代谢能的影响

研究旨在探讨5种不同玉米样品日粮中,添加木聚糖酶(0和16 000 BXU/kg)对肉鸡生长性能和表观代谢能(AME)的影响。试验对不同的玉米指标进行了检测分析,以判断是否可通过某些指标预估生长性能或AME。试验共采用720羽肉鸡,每处理6个重复,每重复12只鸡,饲喂阶段0～18日龄。玉米样品通过近红外反射光谱法(NIR)进行淀粉、蛋白、粗纤维、脂肪、蛋白溶解度指数(PSI)和角质率分析。结果表明:不同收获区域对18日龄肉鸡的采食量(FI)、体增质量(BWG)和饲料转化率(FCR)没有显著影响。而添加木聚糖酶可显著改善肉鸡的生长性能。并显著提高AME。虽然统计学上不同玉米来源对肉鸡生长性能没有显著的影响,但是其对于AME有很强的影响趋势。任何一个营养近似值指标或理化指标与生长性能或AME都没有显著的相关性。可能表明这些单一的指标并不适合来预估生长性能或AME。

Effect of mucin 4 allele on susceptibility to experimental infection with enterotoxigenic F4 Escherichia coli in pigs fed experimental diets

Background: This study investigated the validity of the DNA-marker based test to determine susceptibility to ETECF4 diarrhoea by comparing the results of two DNA sequencing techniques in weaner pigs following experimental infection with F4 enterotoxigenic Escherichia coli(ETEC-F4). The effects of diet and genetic susceptibility were assessed by measuring the incidence of piglet post-weaning diarrhoea(PWD), faecal E. coli shedding and the diarrhoea index.Results: A DNA marker-based test targeting the mucin 4 gene(MUC4) that encodes F4 fimbria receptor identified pigs as either fully susceptible(SS), partially or mildly susceptible(SR), and resistant(RR) to developing ETEC-F4 diarrhoea. To further analyse this, DNA sequencing was undertaken, and a significantly higher proportion of C nucleotides was observed for RR and SR at the Xba I cleavage site genotypes when compared to SS. However, no significant difference was found between SR and RR genotypes. Therefore, results obtained from Sanger sequencing retrospectively allocated pigs into a resistant genotype(MUC4–), in the case of a C nucleotide, and a susceptible genotype(MUC4+), in the case of a G nucleotide, at the single nucleotide polymorphism site. A total of 72 weaner pigs(age ~ 21 days), weighing 6.1 ± 1.2 kg(mean ± SEM), were fed 3 different diets:(i) positive control(PC) group supplemented with 3 g/kg zinc oxide(Zn O),(ii) negative control(NC) group(no Zn O or HAMSA),and(iii) a diet containing a 50 g/kg high-amylose maize starch product(HAMSA) esterified with acetate. At days five and six after weaning, all pigs were orally infected with ETEC(serotype O149:F4;toxins LT1, ST1, ST2 and EAST). The percentage of pigs that developed diarrhoea following infection was higher(P = 0.05) in MUC4+ pigs compared to MUC4– pigs(50% vs. 26.8%, respectively). Furthermore, pigs fed Zn O had less ETEC-F4 diarrhoea(P = 0.009) than pigs fed other diets, however faecal shedding of ETEC was similar(P > 0.05) between diets.Conclusion: These results confirm that MUC4+ pigs have a higher prevalence of ETEC-F4 diarrhoea following exposure, and that pigs fed Zn O, irrespective of MUC4 status, have reduced ETEC-F4 diarrhoea. Additionally,sequencing or quantifying the single nucleotide polymorphism distribution at the Xba I cleavage site may be more reliable in identifying genotypic susceptibility when compared to traditional methods.