日粮中添加蛋白酶对断奶仔猪生长性能、肠道形态和消化酶的影响

为研究日粮中添加蛋白酶对断奶仔猪生长性能、肠道形态和消化酶活性的影响,试验采用单因子完全随机试验设计,将50头28日龄断奶仔猪随机分为两组,对照组饲喂基础日粮,试验组在基础日粮中添加0.1%复合蛋白酶制剂。结果表明:与对照组相比,试验组断奶仔猪的平均日增重提高5.1%,料重比降低4.67%;试验组空肠的绒毛高度(VH)显著提高40.66μm(P<0.05),且绒毛隐窝比值提高了9.94%(P<0.05);试验组空肠的蛋白酶活性、淀粉酶活性均极显著升高,分别提高了2.89U/mL和23.25U/mL(P<0.01)。综上所述,在饲料中添加蛋白酶明显提高了仔猪的日增重,降低了料重比和成本,且促进了肠道绒毛和隐窝结构的发育和肠道消化酶的活性,改善了仔猪的生长性能。     

Effects of graded levels of xylo-oligosaccharides on growth performance,serum parameters,intestinal morphology,and intestinal barrier function in weaned piglets

The objective of this study was to investigate the effects of xylo-oligosaccharides (XOSs) supplementation on growth performance, serum parameters, small intestinal morphology, intestinal mucosal integrity, and immune function in weaned piglets. A total of 240 weaned piglets with an average body weight (BW) of 8.82 ± 0.05 kg (28 d of age) were assigned randomly to four dietary treatments in a 28-d trial, including a control (CON) diet and three diets with XOS supplementation at the concentration of 100 (XOS100), 500 (XOS500), and 1,000 (XOS1000) mg/kg. There were four replicates per treatment with 15 pigs per pen. From day 1 to 14, there were no differences (P > 0.05) in average daily gain (ADG), average daily feed intake, and gain to feed ratio (G:F) during the different treatments. The different doses of XOSs showed a quadratic effect on BW on day 28, ADG, and G:F on day 1 to 28 of piglets (P < 0.05). From day 15 to 28, ADG of pigs fed the XOS500 diet was higher (P < 0.05) than pigs fed the CON diet. During the overall period (day 1 to 28), pigs fed the XOS500 diet had a higher BW, ADG, and G:F than pigs fed the CON diet (P < 0.05). In addition, compared with the CON group, the XOS500 group had significantly higher serum total antioxidant capacity, total superoxide dismutase and catalase levels, and lower malondialdehyde levels on days 14 and 28 (P < 0.05). The serum immunoglobulin G (IgG) concentration in the XOS500 group was also significantly higher compared with the CON group on days 14 and 28 (P < 0.05). However, serum immunoglobulin A and immunoglobulin M were not affected by the dietary treatments. Supplementation of XOS500 to the feed significantly increased the villus height (VH) and VH to crypt depth ratio in the jejunum and ileum in comparison with the CON and XOS1000 groups. Moreover, the XOS500 group significantly elevated the expression levels of occludin and zonula occludens protein-1 in the ileum compared with the CON group. The ileal interleukin (IL)-1β, IL-8, and interferon (IFN)-γ mRNA expression levels in the XOS100 and XOS500 groups were markedly lower than in the CON group. In contrast, the ileal IL-10 mRNA expression levels were remarkably higher in the XOS500 than in the CON group. In conclusion, XOSs have a beneficial effect on growth performance by improving serum antioxidant defense system, serum IgG, small intestinal structure, and intestinal barrier function in weaned piglets.     

共轭亚油酸对断奶仔猪生产性能及免疫的影响

试验选择30日龄、体重相近的杜×长×大三元杂交断奶仔猪40头,按体重和性别随机分为4个组,公母各半。各组在相同基础日粮中分别添加0%、0.5%、1.0%和2.0%共轭亚油酸(CLA),研究日粮中添加CLA对断奶仔猪生产性能与免疫的影响。结果表明,当日粮中CLA的添加量为1.0%和2.0%时,可以显著提高断奶仔猪试验末重、日增重、饲料利用率、IgM水平、T淋巴细胞转化率、CD4 及CD4 /CD8 比例,降低仔猪采食量及腹泻率(P<0.05)。而对IgG、IgA水平及CD8 无显著影响(P>0.05)。     

凝结芽孢杆菌BC66对断奶仔猪生长性能、养分表观消化率及肠道形态结构的影响

为研究凝结芽孢杆菌BC66对断奶仔猪生长性能、养分表现消化率及肠道形态结构的影响,试验选取同批次体况相近的21日龄[杜×长×大,(6.39±0.36)kg]断奶仔猪180头,随机分为3组,每组3个重复,每个重复20头.对照组饲喂基础日粮,试验Ⅰ、Ⅱ组分别在基础日粮中添加1.0×106、1.0×107 cfu/g凝结芽孢...     

不同来源单宁酸替代氧化锌对断奶仔猪生长性能、腹泻率和肠道形态的影响

试验旨在研究2种不同来源的水解单宁酸,栗木水解单宁酸(HCT)和五倍子水解单宁酸(HGT)对断奶仔猪的生长性能、腹泻率和肠道发育的影响。试验选用平均体重10 kg左右的"杜×长×大"三元杂交猪117头,随机分为3组,每组3个重复,每个重复13头猪。对照组仔猪饲喂基础日粮+高锌(1600 g/t,以ZnO计),2个处理组在基础日粮中添加同一水平不同来源的HCT和HGT(以单宁酸计,折算后添加),试验期25 d。结果显示,HCT组和HGT组仔猪的平均日增重显著高于对照组(P<0.05)。饲养1~2周,HCT组和HGT组仔猪的腹泻率极显著高于对照组(P<0.01),第3周后,各组仔猪腹泻率差异不显著(P>0.05)。HCT组和HGT组仔猪的空肠黏膜厚度显著高于对照组(P<0.05)。结果表明,添加HCT和HGT均能改善仔猪的生长性能,对采食量的影响不大,HCT对仔猪腹泻率的控制效果优于HGT,且可改善仔猪肠道发育和肠黏膜功能。     

紫花苜蓿多糖对仔猪生长性能及小肠形态的影响

文章旨在评价饲粮中添加紫花苜蓿多糖对仔猪生长性能及小肠形态的影响。试验选取100头体重接近的28日龄断奶仔猪,随机分为对照组和试验1、2、3组,适应期7d,期间饲喂基础饲粮,正式试验时试验组分别在对照组基础饲粮中添加0.025%、0.05%、0.075%的紫花苜蓿多糖,处理42d。结果发现,紫花苜蓿多糖处理组仔猪平均末重、ADG显著提高(P<0.05),FCR降低(P<0.05),而ADFI无显著变化(P>0.05)。相比于对照组,试验1、2、3组仔猪平均末重分别增加7.8%、11.6%、10.2%(P<0.05),ADG分别增加12.4%、18.2%、15.9%(P<0.05),FCR显著降低10.1%、12.5%、10.2%(P<0.05)。同时,饲粮中添加紫花苜蓿多糖显著改变小肠肠道形态,相比对照组,试验2、3组仔猪十二指肠V/C分别降低8.9%、7.7%(P<0.05);试验2、3组仔猪空肠VH分别增加8.3%、7.0%(P<0.05),CD分别降低8.8%、7.7%(P<0.05),试验1、2、3组V/C分别增加7.6%、18.8%、15.9%(P<0.05)。除此之外,试验2、3组仔猪回肠VH较对照组分别增加9.4%、6.2%(P<0.05),CD分别降低10.0%、9.6%(P<0.05),试验1、2、3组V/C分别增加10.4%、21.5%、17.5%(P<0.05)。结果表明,饲粮中添加紫花苜蓿多糖显著改善仔猪小肠形态,促进其生长发育,添加量为0.05%时效果最佳。     

Effects of crude protein and lactose levels in diets on growth performance,intestinal morphology,and expression of genes related to intestinal integrity and immune system in weaned piglets

To evaluate the effects of crude protein (CP) and lactose (LAC) for weaned piglets on performance, intestinal morphology, and expression of genes related to intestinal integrity and immune system, 144 piglets with initial weight 7.17 ± 0.97 kg were allotted in a randomized design, in a 2 × 3 factorial arrangement (20.0% and 24.0% CP and 8.0%, 12.0%, and 16.0% LAC) with eight replicates. Piglets fed 20.0% CP had greater weight gain and feed intake. Including 12.0% LAC in the 20.0% CP diet provided higher villous height in the duodenum than 8.0% LAC, and 12.0% or 16.0% LAC in the 24.0% CP diet resulted in higher villous height in the jejunum and ileum, and higher villi/crypt ratio in the ileum than 8.0% LAC. No effects of CP and LAC on interleukin‐1β and tumor necrosis factor‐α mRNA were observed. The 16.0% LAC diet provided higher gene expression of transforming‐β1 growth factor. Feeding 20.0% CP resulted in better performance than 24.0% CP. The 12.0% LAC diet promoted greater genetic expression of occludin and zonula occludens. Including 12.0% LAC in the diet may improve intestinal epithelial morphology and integrity, and these improvements are more evident when piglets are fed diets with 24.0% CP.     

刺五加提取物对断奶仔猪生长性能、免疫功能和肠道菌群的影响

文章旨在研究刺五加提取物对断奶仔猪生长性能、免疫功能和肠道菌群的影响,并探讨其替代抗生素的效果。试验选取150头健康、体重相近的21日龄杜×长×大断奶仔猪,随机分为3组,每组5个重复,每个重复单独一栏饲养,每栏10头仔猪。3个处理组分别为:只饲喂基础日粮的对照组,在基础日粮中添加20 mg/kg硫酸粘杆菌素的抗生素组,以及在基础日粮中添加0.1%刺五加提取物的刺五加组。试验开始前预饲3 d,正式试验28 d。结果表明:与饲喂基础日粮相比,日粮添加抗生素和刺五加提取物显著提高了断奶仔猪的平均日增重(P <0.05),降低了料重比和腹泻率(P <0.05),且日粮添加刺五加提取物的效果优于添加硫酸粘杆菌素;与对照组相比,抗生素组和刺五加组均显著提高了断奶仔猪血清中IgG和IgM水平(P <0.05),且日粮添加抗生素有提高血清中IgA水平的趋势,但差异不显著(P> 0.05);此外,抗生素和刺五加提取物的添加还显著降低了断奶仔猪盲肠中大肠杆菌和沙门氏菌的数量(P <0.05),添加抗生素显著降低了盲肠中双歧杆菌和乳酸杆菌的数量(P <0.05),添加刺五加提取物反而显著提高了盲肠中双歧杆菌的数量(P <0.05)。综上所述,刺五加提取物在提高断奶仔猪生长性能、免疫功能和调节肠道菌群方面均具有一定的优势,是一类潜力较大的抗生素替代品。     

The effects of dietary supplementation with porous zinc oxide on growth performance,intestinal microbiota,morphology, and permeability in weaned piglets

The objective of this experiment was to evaluate the effects of dietary supplementation with porous zinc oxide (HiZox) on growth performance, intestinal microbiota, morphology, and permeability in weaned piglets. A total of 128 weaned piglets [(Landrace × Yorkshire) × Duroc] with an average body weight (BW) of (6.55 ± 0.25 kg; 21 d of age) were randomly assigned to four dietary treatments: (1) a corn‐soybean basal diet; (2) basal diet + 3,000 mg/kg conventional ZnO; (3) basal diet + 200 mg/kg HiZox; (4) basal diet + 500 mg/kg HiZox. The experiments lasted for 28 days. Incremental HiZox in the diet increased ADG (linear p = 0.015; quadratic p = 0.043) and ADFI (linear p = 0.027; quadratic p = 0.038), and the diarrhea index decreased linearly and quadratically (p < 0.01) as HiZox supplemented increased. Furthermore, supplementation with HiZox increased the amounts of Lactobacillus spp. (p < 0.05) in the ileum and cecum in comparison with that of control treatment or 3,000 mg/kg ZnO treatment, while decreased the populations of Escherichia coli, Clostridium coccoides, and Clostridium. leptum subgroup (p < 0.05) in the ileum and cecum relative to those in control treatment. The addition of HiZox increased the villus height and villus‐to‐crypt ratio (VC) of duodenum, jejunum, and ileum (p < 0.05), while decreased the crypt depth of jejunum (p < 0.05) and tended to reduce the crypt depth of duodenum (p < 0.10) compared with the control treatment. Piglets fed with 500 mg/kg HiZox had lower serum D‐lactate and diamine oxidase (DAO) than those fed with basal control diet or 3,000 mg/kg ZnO diet (p < 0.01). The results suggested that supplementation with HiZox modulated intestinal microbial composition and improved intestinal morphology, which may exert protective effects on the integrity of the mucosal barrier function of weaned piglets, was as efficacious as pharmaceutical doses of ZnO in enhancing growth performance, indicating that the HiZox may be a promising alternative to pharmaceutical doses of ZnO.     

山楂提取物对断奶仔猪生长性能、免疫功能、抗氧化能力及肠道微生物的影响研究

为探讨不同添加量山楂提取物(CF)对断奶仔猪生长性能、免疫功能、抗氧化能力和肠道微生物的影响,试验选择体重为(8.85±0.73)kg左右、健康状况良好的28日龄"杜×长×大"断奶仔猪30头,按体重相近的原则随机分为5组,每组6个重复,每个重复1头仔猪.对照组(CON组)饲喂基础日粮,抗生素组(CTC组)是在基础日粮中...     

微生态制剂对断奶仔猪生长性能、器官重及其胃肠道发育的影响

通过给苏淮断奶仔猪饲喂微生态制剂(植物乳杆菌为主)研究其对断奶仔猪生长性能、器官重及其胃肠道发育的影响,分析仔猪生长性能与器官重、小肠形态、肠道pH的相关性,探讨微生态制剂缓解仔猪断奶应激的可能机制。选取健康、胎次和体重相近[(9.34±0.33)kg]的144头28日龄苏淮断奶仔猪,随机分为对照组(基础日粮)、抗生素组(基础日粮+抗生素)、微生态制剂组(基础日粮+微生态制剂),每组6个重复,每个重复8头仔猪。预试期为3d,试验于32日龄开始,59日龄结束时屠宰采样。结果表明,与对照组相比,微生态制剂可显著提高断奶仔猪平均日增重(ADG)和平均日采食量(ADFI)(P0.05),降低料重比(F/G)和腹泻率(P0.05);显著提高(P0.05)断奶仔猪脾脏相对重量;显著增加断奶仔猪十二指肠绒毛高度(P0.05),显著降低十二指肠、空肠、回肠绒隐比(P0.05),十二指肠、空肠、回肠隐窝深度有下降趋势,但差异不显著(P0.05);显著降低(P0.05)断奶仔猪盲肠、结肠pH。与抗生素组相比,微生态制剂组对各指标无显著影响(P0.05)。相关性分析显示,ADG增加与肝脏相对重量增加显著相关(P0.05);ADFI增加与十二指肠和脾脏相对重量、回肠绒隐比增加显著相关(P0.05),与结肠和盲肠pH、回肠隐窝深度降低显著相关(P0.05);F/G降低与结肠相对重量增加呈显著相关(P0.05);腹泻率下降与十二指肠相对重、脾脏相对重量、十二指肠和空肠绒隐比增加呈显著相关(P0.05)。由此看出,微生态制剂可通过增加器官重,改善肠道形态,降低胃肠道pH,提高断奶仔猪生长性能、降低腹泻率,缓解断奶应激对仔猪的影响,该微生态制剂具有替代抗生素的潜力。     

Effects of rumen‐protected folic acid and dietary protein level on growth performance,ruminal fermentation,nutrient digestibility and hepatic gene expression of dairy calves

This study evaluated the effects of rumen‐protected folic acid (RPFA) supplementation and dietary protein level on growth performance, ruminal fermentation, nutrient digestibility and hepatic gene expression in calves. Forty Holstein male calves (161 ± 5.7 days of age and 192 ± 5.4 kg of body weight) were assigned to one of four groups in a randomized experimental design with a 2 × 2 factorial arrangement. Moderate crude protein (130.1 g CP/kg [MCP] or high crude protein (150.2 g CP/kg [HCP]) diets were fed without (RPFA?) or with 3.6 mg FA (RPFA+) as RPFA per kg dietary dry matter (DM). Calves were fed a total mixed ration with a corn silage to concentrate ratio of 50:50 on a DM basis. The CP×RPFA interaction was not significant for any of the studied variables. The unchanged DM intake, higher average daily gain and lower feed conversion ratio were observed for HCP or RPFA+. Ruminal pH was lower, and total volatile fatty acids (VFA) concentration was higher for HCP or RPFA+. Acetate proportion was higher, and propionate proportion was lower for HCP or RPFA+. As a result, the higher acetate to propionate ratio was observed. Ruminal ammonia N was higher for HCP, but was lower with RPFA supplementation. The higher digestibility of DM, OM, CP and NDF was observed. Blood glucose and insulin were unchanged, but albumin, total protein, GH and IGF‐1 were higher. Similarly, the higher hepatic expression of GH, IGF‐1, GHR, IGF‐1R, PI3K, mTOR and P70S6K was observed for HCP or RPFA+. The results indicated that increasing dietary CP content or supplementation with RPFA promoted growth performance of calves by improving nutrient utilization and up‐regulating hepatic expression of gene related to protein synthesis.     

Effects of dietary supplementation with epidermal growth factor on nutrient digestibility,intestinal development and expression of nutrient transporters in early‐weaned piglets

The abnormalities in intestinal morphology and digestive function during weaning are associated with the loss of milk‐borne growth factors. Epidermal growth factor (EGF) has been shown to stimulate the growth of animals. This study was to determine the effect of dietary EGF on nutrient digestibility, intestinal development and the expression of genes encoding nutrient transporters in weaned piglets. Forty‐two piglets were weaned at 21 days and assigned to one of three treatment groups: (1) basal diet (control), (2) basal diet + 200 µg/kg EGF or (3) basal diet + 400 µg/kg EGF. Each treatment consisted of 14 replicates, and seven piglets from each treatment were sampled on day 7 and 14. The EGF supplementation significantly elevated (p < 0.05) the coefficients of total tract apparent digestibility of crude protein, calcium and phosphorus, but tended to decrease sucrase activity (p < 0.10) than the control group. At day 7 post‐weaning, animals receiving EGF diets showed a tendency (p < 0.10) towards greater ileal villus height (VH), jejunal crypt depth (CD) and duodenal VH:CD when compared with the control group. Moreover, the mRNA levels of glucose transporter 2 (Slc2a2), neutral amino acid transporter (Slc6a19) and calbindin D9k (S100G) tended to be higher (p < 0.10) for EGF groups than the control group. By day 14, EGF supplementation markedly enhanced (p < 0.05) the VH, CD and VH:CD in the jejunum compared to the control group. This addition also up‐regulated (p < 0.05) the mRNA level and the protein abundance of peptide transporter 1 than the control group. These findings demonstrated that dietary EGF beneficially enhanced nutrient digestibility, improved intestinal development and increased the mRNA expression of nutrient transporters in weaned piglets.     

Functional amino acid supplementation,regardless of dietary protein content,improves growth performance and immune status of weaned pigs challenged with Salmonella Typhimurium

High dietary protein may increase susceptibility of weaned pigs to enteric pathogens. Dietary supplementation with functional amino acids (FAA) may improve growth performance of pigs during disease challenge. The objective of this study was to evaluate the interactive effects of dietary protein content and FAA supplementation above requirements for growth on performance and immune response of weaned pigs challenged with Salmonella. Sixty-four mixed-sex weanling pigs (13.9 ± 0.82 kg) were randomly assigned to dietary treatments in a 2 × 2 factorial arrangement with low (LP) or high protein (HP) content and basal (AA–) or FAA profile (AA+; Thr, Met, and Trp at 120% of requirements) as factors. After a 7-d adaptation period, pigs were inoculated with either a sterile saline solution (CT) or saline solution containing Salmonella Typhimurium (ST; 3.3 × 10⁹ CFU/mL). Growth performance, body temperature, fecal score, acute-phase proteins, oxidant/antioxidant balance, ST shedding score in feces and intestinal colonization, fecal and digesta myeloperoxidase (MPO), and plasma urea nitrogen (PUN) were measured pre- and postinoculation. There were no dietary effects on any measures pre-inoculation or post-CT inoculation (P > 0.05). Inoculation with ST increased body temperature and fecal score (P < 0.05), serum haptoglobin, plasma superoxide dismutase (SOD), malondialdehyde (MDA), PUN, and fecal MPO, and decreased serum albumin and plasma reduced glutathione (GSH):oxidized glutathione (GSSG) compared with CT pigs (P < 0.05). ST-inoculation reduced average daily gain (ADG) and feed intake (ADFI) vs. CT pigs (P < 0.05) but was increased by AA+ vs. AA– in ST pigs (P < 0.05). Serum albumin and GSH:GSSG were increased while haptoglobin and SOD were decreased in ST-inoculated pigs fed AA+ vs. AA– (P < 0.05). PUN was higher in HP vs. LP-fed pigs postinoculation (P < 0.05). Fecal ST score was increased in ST-inoculated pigs on days 1 and 2 postinoculation and declined by day 6 (P < 0.05) in all pigs while the overall score was reduced in AA+ vs. AA– pigs (P < 0.05). Cecal digesta ST score was higher in HP vs. LP-fed pigs and were lower in AA+ compared with AA– fed pigs in the colon (P < 0.05). Fecal and digesta MPO were reduced in ST pigs fed AA+ vs. AA– (P < 0.05). These results demonstrate a positive effect of FAA supplementation, with minimal effects of dietary protein, on performance and immune status in weaned pigs challenged with Salmonella.     

宫内发育迟缓仔猪小肠形态和屏障功能相关基因的表达特征

为了研究宫内发育迟缓(IUGR)仔猪小肠形态和屏障功能相关基因的表达特征,选取24窝"长白×大白"杂交新生仔猪,每窝选取1头IUGR仔猪和1头正常出生体重(NBW)仔猪,分别于7、21和28日龄屠宰8头IUGR仔猪和8头NBW仔猪,采集小肠样品进行分析.结果表明:1)与NBW仔猪相比,IUGR仔猪7日龄时空肠绒毛高度、...     

花椰菜尾菜发酵饲料对保育猪生长性能、血清生化指标、小肠组织形态及经济效益的影响

为研究花椰菜尾菜发酵饲料对保育猪生长性能、血清生化指标、小肠组织形态及经济效益的影响.选取42头体重相近(11.40±1.36)kg、体况良好的40日龄保育猪,随机分为两组,每组3个重复,每个重复7头.对照组饲喂基础饲粮,试验组饲喂由80％基础饲粮和20％花椰菜尾菜发酵饲料组成的试验饲粮.试验共30 d,其中预试期8 ...     

Effects of dietary Bacillus coagulans and yeast hydrolysate supplementation on growth performance,immune response and intestinal barrier function in weaned piglets

The present study investigated the effects of Bacillus coagulans and yeast hydrolysate supplementation on growth performance, immune response and intestinal barrier function of weaned piglets. Twenty-four weaned piglets with an average body weight (BW) of 6.89 ± 0.15 kg were divided into four diets for 28 days. The treatments were basal diet (control), basal diet supplemented with antibiotic (20 mg/kg colistin sulphate and 40 mg/kg bacitracin zinc, AT), probiotics (400 mg/kg Bacillus coagulans ≥5 × 109 CFU/g, BC) or yeast hydrolysate (5000 mg/kg yeast hydrolysate, YH). Average daily gain (ADG) and average daily feed intake (ADFI) were improved by AT and YH diets (p < 0.05), while BC diet only increased ADG (p < 0.05). The complement 3 (C3), lysozyme (LZM) and tumour necrosis factor-α (TNF-α) concentrations in serum were increased in BC diet (p < 0.05). Feeding AT and YH caused the increase of jejunal villus height (p < 0.05), and a higher ratio of villus height/crypt depth was observed in AT, BC and YH groups (p < 0.05). The mRNA expression of zonula occludens-1 (ZO-1) in jejunal mucosa was up-regulated by AT, BC and YH diets (p < 0.05). Dietary AT, BC or YH inclusion decreased the interleukin-1β (IL-1β) concentration and TNF-α mRNA expression (p < 0.05), and YH supplementation even down-regulated toll-like receptor 4 (TLR4) and CD14 expressions (p < 0.05). In summary, the dietary administration of BC or YH both improves growth performance through promoting the intestinal barrier function, indicating both of them can serve as potential alternatives to antibiotics growth promoters for the piglet production.     

Effects of dietary iron level on growth performance,hematological status,and intestinal function in growing-finishing pigs

This study investigated the different addition levels of iron (Fe) in growing-finishing pigs and the effect of different Fe levels on growth performance, hematological status, intestinal barrier function, and intestinal digestion. A total of 1,200 barrows and gilts ([Large White × Landrace] × Duroc) with average initial body weight (BW; 27.74 ± 0.28 kg) were housed in 40 pens of 30 pigs per pen (gilts and barrows in half), blocked by BW and gender, and fed five experimental diets (eight replicate pens per diet). The five experimental diets were control diet (basal diet with no FeSO₄ supplementation), and the basal diet being supplemented with 150, 300, 450, or 600 mg/kg Fe as FeSO₄ diets. The trial lasted for 100 d and was divided into the growing phase (27 to 60 kg of BW) for the first 50 d and the finishing phase (61 to 100 kg of BW) for the last 50 d. The basal diet was formulated with an Fe-free trace mineral premix and contained 203.36 mg/kg total dietary Fe in the growing phase and 216.71 mg/kg in the finishing phase based on ingredient contributions. And at the end of the experiment, eight pigs (four barrows and four gilts) were randomly selected from each treatment (selected one pig per pen) for digesta, blood, and intestinal samples collection. The results showed that the average daily feed intake (P = 0.025), average daily gain (P = 0.020), and BW (P = 0.019) increased linearly in the finishing phase of pigs fed with the diets containing Fe. On the other hand, supplementation with different Fe levels in the diet significantly increased serum iron and transferrin saturation concentrations (P < 0.05), goblet cell numbers of duodenal villous (P < 0.001), and MUC4 mRNA expression (P < 0.05). The apparent ileal digestibility (AID) of amino acids (AA) for pigs in the 450 and 600 mg/kg Fe groups was greater (P < 0.05) than for pigs in the control group. In conclusion, dietary supplementation with 450 to 600 mg/kg Fe improved the growth performance of pigs by changing hematological status and by enhancing intestinal goblet cell differentiation and AID of AA.     

Gene expression and morphological changes in the intestinal mucosa associated with increased permeability induced by short‐term fasting in chickens

Short‐term fasting for 4.5 and 9 hr has been demonstrated to increase intestinal permeability (IP) in chickens. This study aimed to investigate the effects of 0, 4.5, 9 and 19.5 hr fasting on intestinal gene expression and villus‐crypt architecture of enterocytes in jejunal and ileal samples. On day 38, Ross‐308 male birds were fasted according to their group and then euthanised. Two separate intestinal sections (each 2 cm long, jejunum and ileum) were collected. One section was utilised for villus height and crypt depth measurements. The second section was snap‐frozen in liquid nitrogen for quantitative polymerase chain reaction (qPCR) analysis of tight junction proteins (TJP) including claudin‐1, claudin‐3, occludin, zonula occludens (ZO‐1, ZO‐2), junctional adhesion molecules (JAM) and E‐cadherin. Additionally genes involved in enterocyte protection including glucagon‐like peptide (GLP‐2), heat‐shock protein (HSP‐70), intestinal alkaline phosphatase (IAP), mammalian target of rapamycin (mTOR), toll‐like receptors (TLR‐4), mucin (MUC‐2), cluster differentiation (CD‐36) and fatty acid‐binding protein (FABP‐6) were also analysed. Normally distributed data were analysed using one‐way analysis of variance ANOVA. Other data were analysed by non‐parametric one‐way ANOVA. Villus height and crypt depth were increased (p < .05) only in the ileum after fasting for 4.5 and 9 hr compared with non‐fasting group. mRNA expression of claudin‐3 was significantly reduced in the ileum of birds fasted for 9 and 19.5 hr, suggesting a role in IP modulation. However, all other TJP genes examined were not statistically different from control. Nevertheless, ileal FABP‐6 of all fasted groups was significantly reduced, which could possibly be due to reduced bile acid production during fasting.     

日粮ADF水平对断奶肉兔肠道健康、营养物质消化及生产性能的影响

选用100只体重相近的35日龄断奶新西兰肉兔,随机分为5组,分别饲喂不同水平酸性洗涤纤维(ADF,13%、16%、19%、22%和25%)的日粮,探讨我国生长肉兔适宜的ADF需要量。结果表明:试兔肠道健康状况受日粮ADF水平影响较大,13%和16%ADF组肉兔腹泻发生率和健康风险指数明显高于其他各处理组;平均腹泻时间随ADF水平的提高逐渐下降,其中,25%组显著低于13%组(P<0.05)。13%、16%ADF组的空肠、盲肠和结肠pH均显著低于19%、22%和25%ADF组(P<0.05)。随日粮ADF水平升高,粗纤维消化率逐渐下降(P<0.05),粗蛋白质、粗脂肪和能量消化率先增加后降低(P<0.05),分别以19%和16%ADF组最高。随日粮ADF水平升高,平均日采食量逐渐增加;日增重先增加后降低,以19%ADF组最高,为31.43 g/d。综合分析,断奶至2月龄肉兔适宜的ADF水平为19%。