Effects of dietary Hermetia illucens meal inclusion on cecal microbiota and small intestinal mucin dynamics and infiltration with immune cells of weaned piglets

Background: The constant interaction between diet and intestinal barrier has a crucial role in determining gut health in pigs. Hermetia illucens(HI) meal(that represents a promising, alternative feed ingredient for production animals) has recently been demonstrated to influence colonic microbiota, bacterial metabolite profile and mucosal immune status of pigs, but no data about modulation of gut mucin dynamics are currently available. The present study evaluated the effects of dietary HI meal inclusion on the small intestinal mucin composition of piglets, as well as providing insights into the cecal microbiota and the mucosal infiltration with immune cells.Results: A total of 48 weaned piglets were randomly allotted to 3 dietary treatments(control diet [C] and 5% or10% HI meal inclusion [HI5 and HI10], with 4 replicate boxes/treatment and 4 animals/box) and slaughtered after61 days of trial(3 animals/box, 12 piglets/diet). The cecal microbiota assessment by 16 S r RNA amplicon based sequencing showed higher beta diversity in the piglets fed the HI-based diets than the C(P < 0.001). Furthermore,the HI-fed animals showed increased abundance of Blautia, Chlamydia, Coprococcus, Eubacterium, Prevotella,Roseburia, unclassified members of Ruminococcaceae, Ruminococcus and Staphylococcus when compared to the C group(FDR < 0.05). The gut of the piglets fed the HI-based diets showed greater neutral mucin percentage than the C(P < 0.05), with the intestinal neutral mucins of the HI-fed animals being also higher than the sialomucins and the sulfomucins found in the gut of the C group(P < 0.05). Furthermore, the piglets fed the HI-based diets displayed lower histological scores in the jejunum than the other gut segments(ileum [HI5] or ileum and duodenum [HI10], P < 0.05).Conclusions: Dietary HI meal utilization positively influenced the cecal microbiota and the small intestinal mucin dynamics of the piglets in terms of selection of potentially beneficial bacteria and preservation of mature mucin secretory architecture, without determining the development of gut inflammation. These findings further confirm the suitability of including insect meal in swine diets.

不同比例麸皮和豆腐渣混合饲料对黑水虻幼虫生长特性的影响

随机选取4日龄黑水虻(Hermetia illucens L.)幼虫1 500头,均匀分为5个处理,分别为G1组(100%麸皮)、G2组(75%麸皮+25%豆腐渣)、G3组(50%麸皮+50%豆腐渣)、G4组(25%麸皮+75%豆腐渣)、G5组(100%豆腐渣),每天测定体重、体长和投影面积。结果表明,G2组黑水虻幼虫体重最高,且与其他组差异显著(P<0.05);G1组、G2组黑水虻幼虫体长较长,且体长明显大于其他组;G3组黑水虻幼虫投影面积最大,其次为G2组、G1组;G2组、G3组饲料利用率最高。由生长曲线可知,各组黑水虻幼虫大多经历缓慢生长、快速生长和平缓生长3个时期;从体重、体长及投影面积3项指标看,G2组具有延滞期短、快速增长期长的特点,收获时整体表现较好,而G5组整体表现较差。综上,使用75%麸皮+25%豆腐渣作为饲料有利于黑水虻幼虫的生长发育,且该组饲料转化率最高。

Black soldier fly and gut health in broiler chickens:insights into the relationship between cecal microbiota and intestinal mucin composition

Background:The relationship between diet and intestinal microbiota and mucin composition appears to be fundamental for poultry gut health.The effects of insect meal(whose role as alternative feed ingredient is now well recognized)on gut microbiota and mucin composition have recently been reported in Tenebrio molitor-fed free-range and broiler chickens,but no data are currently available for Hermetia illucens(HI)-fed broilers.The present study evaluated the effects of dietary HI meal inclusion on cecal microbiota and intestinal mucin composition of broiler chickens.Results:A total of 256 male broiler chickens were allotted to 4 dietary treatments(control diet[C]and 5%,10%and 15%HI meal inclusion,with 8 replicate pens/treatment and 8 birds/pen)and slaughtered at 35 d of age(2 animals/pen,16 birds/diet).The cecal microbiota assessment by 16S rRNA amplicon based sequencing showed lower alpha diversity in HI15 chickens(Shannon,P<0.05)and higher beta diversity(Adonis and ANOSIM,P<0.001)in birds fed HI diets than C.Furthermore,HI15 birds displayed significant increase of the relative abundance of Proteobacteria phylum(False Discovery Rate[FDR]<0.05)when compared to HI10.L-Ruminococcus(Ruminococcus from Lachnospiraceae family),Faecalibacterium,Blautia and Clostridium genera were found to be characteristic of HI5 cecal microbiota(FDR<0.05),while broiler chickens fed HI10 and HI15 diets were characterized(FDR<0.05)by Lactobacillus and Ruminococcus(HI10)and Bacteroides,Roseburia and Helicobacter genera(HI15).Periodic-acid Schiff,Alcian Blue pH 2.5 and high iron diamine staining on small and large intestine also demonstrated lower mucin staining intensity in the intestinal villi of HI10 and HI15 birds than C(P<0.05).Conclusions:Dietary HI meal utilization at low inclusion levels(i.e.,5%)positively influenced either the cecal microbiota or the gut mucin dynamics in terms of selection of potentially beneficial bacteria and increase in villi mucins.However,high inclusion levels(in particular the 15%)may have a negative influence in terms of partial reduction of microbial complexity,reduction of potentially beneficial bacteria,selection of bacteria with mucolytic activity and decrease in villi mucins.

Preparation and efficacy evaluation of Paenibacillus polymyxa KM2501-1 microbial organic fertilizer against root-knot nematodes

Root-knot nematodes(RKNs) cause huge yield losses to agricultural crops worldwide. Meanwhile, livestock manure is often improperly managed by farmers, which leads to serious environmental pollution. To resolve these two problems, this study developed a procedure for the conversion of chicken manure to organic fertilizer by larvae of Hermetia illucens L. and Bacillus subtilis BSF-CL. Chicken manure organic fertilizer was then mixed thoroughly with Paenibacillus polymyxa KM2501-1 to a final concentration of 1.5×10^(8)CFU g^(-1). The efficacy of KM2501-1 microbial organic fertilizer in controlling root-knot nematodes was evaluated in pot and field experiments. In pot experiments, applying KM2501-1 microbial organic fertilizer either as a base fertilizer or as a fumigant at the dose of 40 g/pot suppressed root-knot disease by 61.76 and 69.05% compared to the corresponding control treatments, respectively. When applied as a fumigant at the dose of 1 kg m;in field experiments, KM2501-1 microbial organic fertilizer enhanced the growth of tomato plants, suppressed root-knot disease by 49.97%, and reduced second stage juveniles of RKN in soil by 88.68%. KM2501-1 microbial organic fertilizer controlled RKNs better than commercial bio-organic fertilizer in both pot and field experiments. These results demonstrate that this co-conversion process efficiently transforms chicken manure into high value-added larvae biomass and KM2501-1 microbial organic fertilizer with potential application as a novel nematode control agent.

黑水虻虫粉对南美白对虾生长发育的影响

为探究黑水虻(Hermetia illucens L.)虫粉替代鱼粉对南美白对虾(Penaeus vannamei)生长发育的影响,寻求更加优质实惠的蛋白替代品,将基础饲料、黑水虻虫粉、鱼粉按不同比例混合配成饲料对南美白对虾进行饲喂试验,对南美白对虾的体长、体重、饲料系数、蛋白质含量以及酶活性等指标进行测定。结果显示,添加15%黑水虻虫粉的试验组对虾体长、体重、蛋白质含量与对照组相比没有显著性影响(P>0.05)。添加15%黑水虻虫粉的试验组对虾SOD酶活性显著高于对照组(P<0.05)。添加15%黑水虻虫粉的试验组对虾存活率、POD酶活性、CAT酶活性极显著高于对照组(P<0.01)。添加15%黑水虻虫粉的试验组饲料系数极显著低于对照组(P<0.01)。得出结论:在南美白对虾饲料中添加15%黑水虻虫粉对南美白对虾生长发育较为适宜。