饲粮铁添加水平对60～90日龄新西兰肉兔生长性能、屠宰性能及血液指标的影响

本试验旨在研究饲粮铁添加水平对60~90日龄新西兰肉兔生长性能、屠宰性能及血液指标的影响。试验选取104只53日龄体重相近新西兰肉兔,随机分成4个组,每组26个重复,每个重复1只兔。对照组饲喂基础饲粮,试验组分别在基础饲粮中添加50、100、200 mg/kg铁,铁添加形式为七水硫酸亚铁(FeSO4·7H2O),纯度为98%。预试期7 d,正试期30 d。结果表明:1)饲粮铁添加水平对60~90日龄新西兰肉兔平均日增重(ADG)和料重比(F/G)有影响显著(P0.05),对平均日采食量(ADFI)无显著影响(P0.05)。随着饲粮铁添加水平的增加,ADG先增加后降低,F/G先降低后增加;当饲粮铁添加水平为100 mg/kg时,ADG最高,F/G最低。2)饲粮铁添加水平对60~90日龄新西兰肉兔全净膛屠宰率和半净膛屠宰率有显著影响(P0.05),随着饲粮铁添加水平的增加,全净膛屠宰率和半净膛屠宰率先增加后降低,当饲粮铁添加水平为50 mg/kg时最高。3)饲粮铁添加水平对60~90日龄新西兰肉兔肝脏指数无显著影响(P0.05),对肾脏指数和脾脏指数有显著影响(P0.05)。饲粮铁添加水平为50、100、200 mg/kg时,肾脏指数显著高于对照组(P0.05);饲粮铁添加水平为100、200 mg/kg时,脾脏指数显著高于对照组(P0.05)。4)饲粮铁添加水平对60~90日龄新西兰肉兔血液中铁、铜、钙、锌、镁含量无显著影响(P0.05);饲粮铁添加水平对血小板分布宽度(PDW)、平均血小板体积(MPV)、血小板大细胞比率(P-LCR)有显著影响(P0.05)。综合本试验测定指标,60~90日龄新西兰肉兔饲粮中适宜的铁添加水平为50~100 mg/kg。     

富马酸亚铁对肉兔生产性能和肉品质的影响

试验旨在研究饲粮中添加富马酸亚铁对断奶肉兔生产性能和肉品质的影响。选择600只体重相近的28日龄断奶新西兰兔，随机分为5组，每组12个重复，每个重复10只，公母各半。对照组基础饲粮不添加铁，试验组分别添加100 mg/kg硫酸亚铁和25、50、100 mg/kg富马酸亚铁。预试期7 d，正试期42 d。结果表明：与对照组相比，25 mg/kg富马酸亚铁提高了肉兔日增重（P<0.05），降低了耗料增重比（P<0.05），但与100 mg/kg硫酸亚铁组及50、100 mg/kg富马酸亚铁组差异不显著；各试验组胴体重和屠宰率高于对照组（P<0.05），但试验组间差异不显著；25 mg/kg富马酸亚铁组粪便、肝脏和肾脏中铁含量均低于100 mg/kg硫酸亚铁组（P<0.05），心脏和背肌中铁含量与各试验组差异不显著。由此可见，富马酸亚铁可提高肉兔日增重，降低耗料增重比，粪便、肝脏和肾脏中残留铁显著低于硫酸亚铁，可以显著改善肉品质、降低环境污染和节约矿物质资源，本试验条件下富马酸亚铁的适宜添加量为25 mg/kg。     

断奶仔猪缺铁模型的建立及酵母铁对断奶仔猪生长及血液生化指标的影响

本试验旨在探讨缺铁性仔猪模型建立及补充酵母铁或硫酸亚铁后仔猪生长发育、血液指标变化情况和内脏器官铁含量的影响.本试验选择21日龄、初始体重(5.57±0.83)kg的D×L×Y断奶仔猪35头,分为7个处理,每个处理5个重复,每个重复1头猪.仔猪单栏饲养.用铁含量为22.43 mg/kg的基础日粮饲喂4周以耗竭体内储备铁.耗竭期结束后,试验期对照组继续饲喂基础日粮,6个试验组日粮分别在基础日粮中添加铁含量为80、120和180 mg/kg的酵母铁或硫酸亚铁,饲喂10 d.结果表明:仔猪经28 d耗竭后形成缺铁模型.当酵母铁组铁含量为120 mg/kg时,仔猪ADG和ADFI最高,日粮铁的来源和水平的交互作用对ADG和F/G影响显著(P<0.05).铁的来源和水平对仔猪各项血常规和生理生化指标影响不显著(P>0.05).120 mg/kg酵母铁或硫酸亚铁组脾脏、肝脏、肾脏和心脏铁含量均极显著高于对照组(P<0.01),且120 mg/kg硫酸亚铁组在脾脏、肝脏和心脏中的铁含量均极显著高于酵母铁组(P<0.01).酵母铁组的ADG、ADFl、铁蛋白和转铁蛋白较硫酸亚铁组高.由结果可知,补充酵母铁和硫酸亚铁可以改善缺铁情况,且酵母铁的效果优于硫酸亚铁.     

日粮中添加不同水平的β-葡聚糖对肉兔生长性能及腹泻率的影响

为研究肉兔日粮中添加不同水平的β-葡聚糖对其生长性能及腹泻率的影响。试验选择30日龄、体重接近、健康的断奶肉兔80只,按照随机分组原则分成4组,每组20只兔。各组试验肉兔依次饲喂含有0%（对照组）、0.04%（试验1组）、0.06%（试验2组）、0.08%（试验3组）β-葡聚糖的日粮。试验预试期7 d,正式试验期30 d。试验结果表明：试验2组和试验3组的新西兰肉兔的试验末重和平均日增重显著提高（P<0.05）,试验1组的新西兰肉兔试验末重略高于对照组,但差异不显著;试验2组和试验3组的新西兰肉兔料重比比对照组显著降低13.25%和11.04%(P<0.05),试验1组肉兔料重比有降低趋势,但与对照组比差异不显著;β-葡聚糖对新西兰肉兔的平均日采食量未产生显著影响。试验2组和试验3组新西兰肉兔的腹泻率比对照组显著降低了31.91%、47.52(P<0.05);试验1组新西兰肉兔的腹泻率有降低趋势,但未达到显著水平。综上所述,在肉兔日粮中添加β-葡聚糖可以显著提高肉兔的生长性能,并降低腹泻率,考虑生产成本,最适添加量为0.06%。     

噬菌体、益生菌、抗菌肽对肉兔生长性能、肠道菌群及屠宰性能的影响

试验旨在研究基础日粮中添加噬菌体、益生菌、抗菌肽对肉兔的生长性能、肠道菌群及屠宰性能的影响.选取体重相近、30日龄断奶、健康的新西兰肉兔350只,随机分成7组,每组5个重复,每个重复10只兔.对照组肉兔饲喂基础日粮,试验1组、2组、3组、4组、5组和6组分别在基础日粮中加入噬菌体、益生菌、抗菌肽、噬菌体+益生菌、噬菌体...     

黄秋葵对肉兔屠宰性能、免疫性能和抗氧化性能的影响

为研究肉兔基础日粮中添加不同比例黄秋葵粉对肉兔屠宰性能、免疫性能和抗氧化性能的影响,试验选用35日龄健康新西兰肉兔120只,随机分成5组,每组3个重复,每个重复8只,预试期7 d,正试期28 d,试验Ⅰ、Ⅱ、Ⅲ、Ⅳ组分别在基础日粮中添加1％、2％、3％及4％黄秋葵粉.结果表明:与对照组相比,试验Ⅱ、Ⅲ组屠宰体重提高6....     

合生素对断奶肉兔生产性能、免疫指标及肠道生理健康的影响

试验旨在探究合生素应用于断奶肉兔生产中的可行性及使用剂量,选取160只35日龄新西兰肉兔,随机分为4组,每组5个重复,每个重复8只兔.合生素组试验兔分别饲喂添加0.02％、0.04％、0.06％合生素的日粮,对照组饲喂基础日粮.正式试验期42 d.结果 显示,与对照组相比,合生素中剂量组和高剂量组肉兔的平均日增重、平均...     

氨基酸络合铁对生长猪生长性能及有关指标的影响

为了比较评估氨基酸络合铁对生长猪生长性能、铁表观消化率、肤色和血液指标的影响,试验选择70日龄初始体重(27.34±2.55)kg的杜×长×大生长猪108头,分为6个处理,每个处理6个重复,每个重复3头猪。试验用玉米-豆粕型基础日粮。在基础日粮中添加100 mg/kg无机铁(一水硫酸亚铁)构成对照组。在对照组基础上分别添加40、80、120、160 mg/kg氨基酸络合铁构成4个试验组,在对照组基础上添加160 mg/kg无机铁(一水硫酸亚铁)构成正对照组,试验期5周。结果表明:试验0~2周、3~5周及全期,随着日粮中氨基酸铁添加量由40 mg/kg增加到160 mg/kg,生长猪日增重和饲料转化效率均得到改善,并呈极显著的线性关系(P<0.01)。与无机铁日粮组相比,添加160 mg/kg氨基酸络合铁试验组极显著地改善了平均日增重(P<0.01)和饲料转化效率(P<0.05);试验第14天和第35天,随着日粮中氨基酸络合铁添加水平的增加,生长猪对日粮中铁元素的表观消化率均呈显著的线性增加关系(P<0.05),添加160 mg/kg氨基酸络合铁试验组铁元素的表观消化率极显著高于对照组和正对照组(P<0.01);试验第14天和第35天,随着日粮中氨基酸络合铁添加水平的提高,红细胞压积、血红蛋白浓度、血清铁和血清铁与总铁结合力之比都呈显著的线性增加关系(P<0.05),并高于无机铁日粮组(P<0.01),而血清总铁结合力呈显著的线性降低关系(P<0.05);在试验期末,160 mg/kg氨基酸络合铁日粮组显著改善生长猪的肤色状况(P<0.05)。与添加硫酸亚铁相比,在生长猪日粮中添加氨基酸铁络合物可提高生长猪的生长性能和铁表观消化率,改善皮肤红度及血液生化指标。     

合生素对新西兰断奶肉兔屠宰性能、器官指数及血液指标的影响

为了研究合生素对新西兰断奶肉兔屠宰性能、器官指数及血液指标的影响，试验选取160只35日龄，平均体重为1200±25 g新西兰肉兔，随机分为4组，每组 5个重复，每个重复8只兔（公、母各半）。合生素组试验兔分别饲喂添加0.02%、0.04%、0.06%合生素（由芽孢杆菌与低聚木糖复合而成）的日粮，对照组饲喂基础日粮，连续饲喂42天。结果显示：饲料中添加0.04%～0.06%的合生素，可显著提高新西兰断奶肉兔活体重、胴体重、部分脏器（脾脏、胸腺和肝脏）重及脾脏指数、胸腺指数和肝脏指数，血清总蛋白、白蛋白、免疫球蛋白IgA和IgG水平及血清胆固醇含量也显著升高（P＜0.05），血清谷氨酰基转肽酶和碱性磷酸酶水平显著降低（P＜0.05）。可见，由芽孢杆菌与低聚木糖复合而成的合生素在促进新西兰断奶肉兔器官发育、增强免疫机能等方面效果显著，推荐添加剂量为0.04%。 [关键词]合生素|肉兔|屠宰性能|器官指数|血液指标     

湿热条件下非淀粉多糖酶对肉兔生长性能和养分消化率的影响

高温高湿条件下,48只断奶新西兰肉兔随机分为4组,每组12个重复,每个重复1只。研究非淀粉多糖酶对其生长性能、养分消化率的影响。对照组为基础日粮组,试验Ⅰ、Ⅱ、Ⅲ组分别在基础日粮基础上添加0.01%、0.02%、0.03%非淀粉多糖酶。结果表明,试验Ⅱ、Ⅲ组肉兔净增重和日增重明显高于对照组和试验Ⅰ组(P<0.05),饲料效率得到显著改善(P<0.05);试验Ⅱ、Ⅲ组能量、粗纤维、中性洗涤纤维和磷的养分消化率显著高于对照组(P<0.05)。综合考虑,肉兔日粮非淀粉多糖酶适宜添加水平为0.02%。     

Mucosal uptake,mucosal transfer and retention of iron in veal calves

A method for studying iron absorption in humans was adapted to veal calves. Three 10-week-old calves with moderate (calves 1 and 2) or severe (calf 3) iron deficiency were given an abomasal injection of⁵⁹Fe and⁵¹Cr and all their faeces were collected over 15 days in order to measure mucosal uptake, mucosal transfer and retention of iron. The mucosal uptake was 62.2, 53.4 and 71.8% in calves 1, 2 and 3, respectively. The iron retention measured 14 days after administration of the test dose was 57.4, 52.3 and 56.4% in calves 1, 2 and 3, respectively. Maximal plasma activity was found in all three calves between 1 1/2 and 2 h after injection of the test dose. The plasma activity decreased rapidly, with a slight increase between the 5th and the 10th hour. After 21 h, less than 0.25% of the injected dose was still present in 1 litre of plasma. Not all the⁵¹Cr was recovered in the faeces. No⁵⁹Fe was found in the urine but some⁵¹Cr could be detected. The results of this study show that the method described is useful for measuring the different steps of iron absorption in iron-deficient veal calves.Abbreviations Hb haemoglobin concentration - MCV mean corpuscular volume - PCV packed cell volume - PI plasma iron - RBC red blood cell count - R iron retention - TIBC total iron-binding capacity - TIBC-SAT saturation of the total iron-binding capacity - U mucosal uptake     

Comparison effects of dietary iron dextran and bacterial‐iron supplementation on growth performance,fecal microbial flora,and blood profiles in sows and their litters

This study was conducted to compare effects of dietary administration of iron dextran and bacterial‐iron on growth performance, fecal microbial flora, and blood profiles in sows and their litters. A total of 20 multiparous sows (Landrace × Yorkshire) were randomly allotted into two treatments: (i) ID (basal diet, piglets were injected with iron dextran); (ii) BR (basal diet + bacterial‐iron; bacterial‐iron was given to sows, piglets were not injected with iron dextran). There were five replicates per treatment with two sows per replicate. No differences were observed on sow and piglet growth performance, fecal microbial flora as well as sow blood profiles between ID and BR treatments. In piglets, blood iron, red blood cell and hemoglobin concentrations in ID treatment were higher (P < 0.05) on days 12 and 24. Furthermore, concentration of white blood cells in BR treatment was lower (P < 0.05) on day 12. However, the percentage of lymphocytes on day 12 was increased (P < 0.05) in BR treatment. In conclusion, effect of iron dextran and bacterial‐iron has no difference on growth performance in lactating sows and piglets, but iron dextran injection has higher blood iron, white blood cell, red blood cell and hemoglobin concentrations in piglets.     

Investigations on iron bioavailability of different sources and supply levels in piglets

Two experiments were conducted to investigate the iron bioavailability of different sources and supply levels in piglets. In experiment 1, the influence of feeding an iron deficient basal diet or the basal diet supplemented with 28 ppm Fe either in form of Fe-chelate, crystalline Fe-glycinate, or Fe-sulphate on apparent iron digestibility and on blood parameters was determined. In experiment 2, a dose-response approach was used to determine the effects of supplementing an iron-deficient basal diet with 30, 60, or 90 ppm of Fe either in form of crystalline Fe-glycinate or Fe-sulphate on digestibility of Fe, growth and blood parameters. In experiment 1, comparison of iron sources revealed a tendency (0.05 < p < 0.1) for a higher Fe digestibility from Fe-glycinate (40.9%) compared with Fe-chelate (30.8%) or Fe-sulphate (30.7%). Fe-balance was higher (p < 0.05) for Fe-glycinate compared with Fe-sulphate but iron balance was similar for iron sulphate and iron chelate. Those results, however, were not reflected in data of blood parameters. In experiment 2, iron digestibility, blood parameters and performance were significantly (p < 0.05) influenced by iron supply. Effects of iron source on digestibility of iron were lower than observed in the first experiment.     

Effects of iron glycine chelate on laying performance,antioxidant activities,serum biochemical indices,iron concentrations and transferrin mRNA expression in laying hens

This study was conducted to evaluate the effects of iron glycine chelate (Fe‐Gly) on laying performance, antioxidant enzyme activities, serum biochemical indices and iron concentrations in laying hens. A total of 810 laying hens (Hy‐Line Variety White, 26 weeks old) were randomly assigned to six groups with five replicates of 27 layers. Hens in the control group received diet supplemented with 60 mg Fe/kg as FeSO₄, while hens in other five groups received the diet supplemented with 0, 20, 40, 60 and 80 mg Fe/kg from Fe‐Gly respectively. The results showed that dietary Fe‐Gly treatments significantly influenced (p < 0.01) the laying rate and egg weight of layers, compared with the control group. Concerning to CuZn‐superoxide dismutase (CuZn‐SOD) and total superoxide dismutase (T‐SOD) activity, Fe‐Gly groups (60, 80 mg Fe/kg) were promoted significantly (p < 0.01) compared with 0 mg Fe/kg group. The concentrations of Fe in serum, liver, kidney, spleen and ovary were increased significantly with the level dietary Fe‐Gly raised where Fe‐Gly groups (60, 80 mg Fe/kg) had observably higher Fe concentration than the control (p < 0.01) in serum, kidney and spleen. There was a trend that transferrin mRNA expression was decreased with the increase of Fe as Fe‐Gly in diets, and compared with the control, the expression was lower in the group fed diet with 60 mg/kg Fe as Fe‐Gly. In conclusion, Fe‐Gly (60 mg Fe/kg) had improved laying rate, egg weight, SOD enzyme activity, Fe absorption and protein synthesis in body and promoted iron metabolism in laying hens. Moreover, Fe‐Gly (40 mg/kg Fe) had the similar effect with control group. It revealed that FeSO₄ could be substituted by lower concentration of Fe‐Gly and Fe‐Gly may be superior to FeSO₄ for iron fortification to laying hens.     

Expression of iron regulatory proteins in full-term swine placenta

In swine, even though the pregnant sows were with iron abundance, the inborn iron reserve of piglets was compromised. This indicates the insufficiency of molecular machinery involved in local placental iron flux. Here, we investigated the expression of iron regulatory proteins like hepcidin and ferroportin and also their association with iron reserve, inflammation and oxidative stress in placenta of full-term pregnant sows (n = 6). Amplification and sequencing of placental DNA confirmed the presence of hepcidin (MN579557) and ferroportin (MN565887) sequences and their 100% identity with existing GenBank data. Real-time amplification of placental mRNA revealed significant higher expression of hepcidin (p < .05) than ferroportin. Western blot analysis of placental tissues revealed specific bands for both hepcidin (~8 kDa) and ferroportin (~62 kDa) molecules. Immunohistochemistry revealed the immunoreactivity for both proteins in the cytoplasm and membrane of trophoblastic cells of the placenta. Hepcidin and ferroportin expressions were positively associated with placental non-haem iron reserve (p < .0001; p = .033), lipid peroxidation (p = .0060; p < .0001) and reactive oxygen species level (p = .0092; p = .0292). Hepcidin expression was positively associated with interleukin – 6 (p = .0002) and interferon gamma (p < .0001) expressions but ferroportin expression was negatively associated with interleukin-6 (p = .0005), interleukin-1β (p = .0226) and interferon gamma (p = .0059) expressions. This indicates hepcidin and ferroportin may have a role in controlling the local placental iron flux by acting as a molecular bridge between iron trafficking and inflammation.     

铁代谢的研究进展

本文综述了机体对铁的吸收、转运、储藏及其对铁代谢的调节。     

Spontaneous iron accumulation in hepatocytes of a 7-week-old female rat

Spontaneous iron accumulation in hepatocytes was observed in a 7-week-old female Han Wistar GALAS rat. Very fine yellowish brown pigments, which showed a positive reaction with Berlin Blue stain, were apparent in the cytoplasm close to the bile canaliculi, with a diminishing periportal-to-centrilobular gradient. There were also differences in distribution between and within lobes. Transmission electron microscopy revealed cytosolic ferritin and pericanalicular siderosomes in hepatocytes. No degeneration or necrotic changes were observed, and non-hepatocyte cells did not demonstrate any obvious accumulation of iron. There were no abnormalities in the animal other than this finding in the liver.     

The effect of parenteral iron supply on hematology, health, growth and meat classification in veal calves.

Twenty veal calves were fed milk substitute containing 19 mg Fe/kg; ten calves were supplemented with iron in accordance with their requirements and the other 10 were unsupplemented controls. Serum iron (SI), hemoglobin (Hb) and packed cell volume (PCV) were determined at the start of the experiment and then every third week. From 3 weeks after the start to the end of the experiment there were significant differences between SI mean values between treated and untreated calves. In the treated group the Hb mean values were unchanged during the experiment while the untreated group had a significant decrease. The mean PCV values were also decreased. The daily gain was 1.36 g higher per calf in the treated group. The feed consumption per kg gain was 18 g lower and the carcass weight was 4.2 kg higher per calf in the treated group. The points for color and structure of carcass were 2.5 units higher per calf in the untreated group. The incidence of enteritis was less in the treated calves than in the untreated ones.