一种复合植物提取物对罗氏沼虾免疫功能及生长性能的影响

试验旨在研究复合植物提取物对罗氏沼虾免疫功能及生长性能的影响。将地势光照相近的6个池塘随机分成2组(对照组、试验组),每组3个重复,试验组在基础饲料中添加0.20%的复合植物提取物,试验期为84 d。试验结果表明:试验组血液和肝胰腺中的LZM、SOD、CAT、AKP活性及血液吞噬率和吞噬指数在各个时间点均显著高于对照组(P0.05);血液和肝胰腺中的LZM、SOD活性及吞噬率和吞噬指数均在7 d达到峰值,CAT活性在14 d达到峰值;血液中的AKP活性在14 d达到峰值,肝胰腺中AKP活性在28 d达到峰值;试验组注射鳗弧菌的死亡率为56.7%,对照组注射鳗弧菌死亡率为90.0%,复合植物提取物对罗氏沼虾注射鳗弧菌保护率37.04%;试验组罗氏沼虾体重和增重率显著高于对照组(P0.05)。试验表明,投喂0.02%复合植物提取物7 d或14 d,能够提高罗氏沼虾的免疫功能和生长性能。     

复方中药添加剂对罗氏沼虾免疫功能的增强作用

将黄芪、党参、大黄、板蓝根等十余味中草药粉碎过筛后制成复方添加剂按1%、2%、3%的比例添加于基础饲料中制成颗粒药饵投喂罗氏沼虾,对该添加剂对罗氏沼虾免疫功能的影响进行了研究。结果表明,罗氏沼虾血细胞吞噬百分比和吞噬指数、血清溶菌酶活力及酚氧化酶活力均显著提高。经嗜水气单胞菌攻毒后,各试验组的免疫保护率也明显提高。在各试验组中以2%组效果最好。试验证明,该添加剂可显著地提高罗氏沼虾的免疫功能,有效地预防嗜水气单胞菌的感染。     

小球藻对南美白对虾生长性能及免疫功能的影响

基础饲料中添加0.5%、1%和2%的小球藻,饲喂南美白对虾幼虾[体质量(4.26±1.71)g],养殖周期4周,测定各处理组对虾体质量,统计各组存活率,计算对虾特定生长率;利用试剂盒测定了对虾血淋巴和肝胰腺组织中的超氧化物歧化酶(SOD)、一氧化氮合酶(NOS)、酚氧化酶(PO)、溶菌酶(LZM)、酸性磷酸酶(ACP)、碱性磷酸酶(ALP)及总抗氧化能力(T-AOC);副溶血弧菌对剩余对虾进行攻毒,统计对虾死亡率。结果表明:小球藻能够明显促进南美白对虾的生长,显著提高对虾血淋巴和肝胰腺中的SOD、NOS、PO、LZM、ACP、ALP酶活和T-AOC能力,明显降低对虾的攻毒死亡率,从而明显提高南美白对虾的存活率。小球藻的适宜添加量为1%。     

中药益生元微胶囊饲料添加剂对斜带石斑鱼生长和免疫性能的影响

以优化的中药配方与相应的肠道益生菌群进行合理配比形成益生元产品,采用喷雾干燥工艺制备中药复合益生元微胶囊制剂,扫描电镜显示其具有完整的微结构和产品成型率。选择斜带石斑鱼为研究对象,探讨中药复合益生元微胶囊制剂对斜带石斑鱼生长和非特异性免疫的影响。试验结果表明,饲料中添加中药复合益生元微胶囊制剂能极显著提高鱼体生长性能和饲料利用率(P0.01)。攻毒试验结果表明,中药复合益生元微胶囊制剂能显著提高免疫器官脾指数(P0.05),但中药制剂自身存在双向性,在饲喂过程中会出现鱼体免疫器官肝指数和头肾指数下降的现象(P0.05)。与对照组相比,极显著提高机体免疫性细胞吞噬率、超氧化物歧化酶(SOD)活性和溶菌酶(LZM)活性(P0.01),血清(F=9.481,P=0.005)和肝胰(F=9.540,P=0.004)总体抗氧化活力显著提高(P0.05),对于酚氧化还原酶活性的提高不显著(P0.05),HE染色组织病理切片可观察到中药复合益生元微胶囊对于鳗弧菌感染的鱼体受损肝器官具有明显疗效,试验中斜带石斑鱼存活率随饲料中中药益生元微胶囊制剂含量的升高而升高(P0.05)。综上所述,饲料中添加黄连复合益生菌群微胶囊制剂可显著提高斜带石斑鱼非特异性免疫功能和疾病抵抗力(P0.05)。     

黑水虻幼虫粉对罗氏沼虾生长、免疫和抗氧化性能的影响

试验旨在探究饲料中不同比例的黑水虻幼虫粉替代鱼粉对罗氏沼虾（Macrobrachium rosenbergii）生长和免疫功能的影响。选取900尾健康、体重（1.22±0.02） g的罗氏沼虾幼虾,随机分为6组,每组3个重复,每个重复50尾虾,对照组（FM组）饲喂基础饲料,T10组、T20组、T30组、T40组、T50组分别使用黑水虻幼虫粉替代基础饲料中10%、20%、30%、40%和50%的鱼粉。试验期56 d。结果显示,FM组和T10组的饲料系数显著低于其他组（P<0.05）,FM组蛋白质效率显著高于其他组（P<0.05）。FM组、T10组、T20组的血淋巴丙二醛（MDA）含量显著低于T40组、T50组（P<0.05）,T10组的血淋巴溶菌酶（LZM）活性显著高于T30组、T40组、T50组（P<0.05）,T30组、T40组肝胰脏碱性磷酸酶（AKP）及酸性磷酸酶（ACP）活性低于其他试验组。研究表明,使用黑水虻幼虫粉替代10%～20%的鱼粉饲喂罗氏沼虾是可行的。     

中草药制剂对凡纳滨对虾生长及血淋巴中免疫因子的影响

在基础饲料中分别添加3个水平(0.5%、1%、2%)的中草药制剂煎液制成3种试验饲料,同时以基础饲料为对照。采用连续投喂的方法,饲喂对虾30d,分别测定了第5,10,15,20,25,30d血淋巴中的酚氧化酶、过氧化物酶、抗菌活力等免疫因子活性,并对血清中蛋白进行定量。试验结束后,试验组及对照组存活率都很高(95%￣98%),各试验组间无差异(P>0.05)。饲喂1%、2%中草药组增重率、增长率都显著高于(P<0.01)对照组。试验组酚氧化酶活力、过氧化物酶活力、抗菌活力都显著高于对照组(P<0.01)。试验结果表明,中草药制剂能有效促进对虾的生长及提高免疫因子的活性。饲养试验结束7d后,腹腔注射副溶血弧菌进行攻毒试验,在8d内,对照组的死亡率显著高于试验组(P<0.05),试验组免疫保护率为50%￣65%,以2%中草药组最为显著。本试验结果表明:中草药制剂可以促进凡纳滨对虾的生长,增强免疫力和抗病力;从免疫水平和生长水平综合考虑,添加量为1%￣2%为宜。     

芬母多肽对弧菌的杀菌效果及其对罗氏沼虾的安全性测定

为检测芬母多肽的杀菌效果并研究其在罗氏沼虾养殖中的应用,测定了芬母多肽对多种致病性弧菌的杀菌率和最小抑菌浓度(MIC),以及不同浓度芬母多肽对罗氏沼虾幼体、成虾安全性和水质的影响。结果显示:芬母多肽对河流弧菌、霍乱弧菌和溶藻弧菌的杀菌效果较好,对副溶血弧菌的杀菌效果较差;对梅氏弧菌、副溶血弧菌、拟态弧菌的最小抑菌浓度分别为1、0.25和0.25 mg/mL;将芬母多肽投放到养殖用人工海水中,当浓度为0.004 mg/mL时能够杀灭0 d养殖用人工海水中50%左右的细菌,幼体的死亡数显著降低(P<0.05),随着浓度不断增高,养殖用人工海水亚硝酸盐氮和氨氮的含量显著增高(P<0.05),使幼体的死亡数显著增高(P<0.05);芬母多肽对罗氏沼虾成虾的安全浓度为0.05 mg/mL。研究表明,芬母多肽在水产养殖中有广阔的应用前景。     

饲料中添加活性酵母制剂对刺参生长、免疫力和抗病力的影响

本试验旨在研究饲料中添加活性酵母制剂对刺参生长、免疫力和抗病力的影响。采用单因素试验设计,通过在商品配合饲料中分别添加0(对照)、0.025%、0.050%、0.100%、0.200%和0.400%的活性酵母制剂,配制6种试验饲料,饲喂平均初始体重为(4.0±0.1)g的刺参6周。每种饲料设3个重复,每个重复放养15头刺参。6周的养殖试验结束后,每个重复选取10头刺参,每头刺参通过体壁注射灿烂弧菌(Vibrio splendidus)菌悬液0.1 m L(菌悬液浓度为1.5×109CFU/m L),观察记录灿烂弧菌攻毒14 d内的累计死亡率。结果表明:饲料中添加活性酵母制剂能显著提高刺参的特定生长率(P0.05),刺参特定生长率在添加量为0.200%时最高。饲料中添加活性酵母制剂后,刺参体腔液中过氧化氢酶(CAT)活性显著增加(P0.05);活性酵母制剂添加量为0.050%~0.400%时,刺参体腔液中溶菌酶(LZM)活性显著高于对照组(P0.05);活性酵母制剂添加量为0.200%~0.400%时,刺参体腔液中酸性磷酸酶(ACP)活性显著高于对照组(P0.05);活性酵母制剂添加量为0.400%时,刺参体腔液中超氧化物歧化酶(SOD)活性显著高于对照组(P0.05)。饲料中添加活性酵母制剂可降低攻毒14 d后刺参的累计死亡率,活性酵母制剂添加量为0.200%时,累计死亡率最低。由此可知,在本试验条件下,饲料中添加活性酵母制剂可促进刺参生长,提高免疫力和抗病力。综合分析刺参的生长、免疫力和抗病力以及实际生产情况,刺参饲料中活性酵母制剂的适宜添加量为0.200%~0.400%。     

饲料中添加柴胡及其提取物对锦鲤幼鱼生长、生理生化、肝脏抗氧化及抗菌能力的影响

试验旨在研究饲料中添加柴胡及其提取物对锦鲤幼鱼生长、生理生化、肝脏抗氧化及抗菌能力的影响。选取初始体重（21.0±0.5） g的锦鲤幼鱼360尾,随机分为3组,每组3个重复,每个重复40尾锦鲤幼鱼。K组、C组和T组锦鲤幼鱼分别饲喂基础饲料、基础饲料+5‰柴胡生粉和基础饲料+5‰柴胡提取物。试验期14 d。结果显示,锦鲤幼鱼血清中,14 d时,C组的溶菌酶（LZM）和C组、T组的碱性磷酸酶（AKP）活性显著高于0 d,并显著高于K组（P<0.05）。锦鲤幼鱼肝脏中,14 d时C组的LZM、酸性磷酸酶（ACP）和T组的AKP活性显著高于0 d (P<0.05)。14 d时,C组的超氧化物歧化酶（SOD）活性及总抗氧化能力（T-AOC）显著高于0 d (P<0.05),丙二醛（MDA）含量低于0、7 d。攻毒试验中,24 h内K组锦鲤幼鱼的死亡率为41.7%;C组死亡率为18.3%,保护率为56%;T组死亡率为21.7%,保护率为48%。C组锦鲤幼鱼血清中48 h的白细胞介素-13(IL-13)含量显著高于24、96 h (P<0.05);C组、T组48 h的免疫球蛋...     

不同比例的生物饲料对罗氏沼虾生长、消化酶和免疫酶活性的影响

研究旨在观察生物饲料(biological feed)对罗氏沼虾(Macrobrachium rosenbergii)生长、消化酶和免疫酶活性的影响。选用平均体重(0.02±0.01)g的罗氏沼虾28 800尾作为试验对象,随机分成4组,每组设3个重复,每个重复2 400尾虾。分别投喂100%基础饲料(A组)、90%基础饲料+10%生物饲料(B组)、80%基础饲料+20%生物饲料(C组)、70%基础饲料+30%生物饲料(D组),饲养周期为42 d。结果表明:与A组比较,C、D组罗氏沼虾增重率差异显著(P0.05),各组罗氏沼虾的增长率、特定生长率、饲料系数、存活率、肌肉营养指标和氨基酸含量无显著差异(P0.05);B、C、D组罗氏沼虾胰蛋白酶的活性极显著提高(P0.01),C、D组罗氏沼虾淀粉酶、纤维素酶和超氧化物歧化酶的活性显著提高(P0.05),C组罗氏沼虾谷草转氨酶的活性显著提高(P0.05);各组罗氏沼虾脂肪酶、过氧化氢酶、碱性磷酸酶、酸性磷酸酶和谷丙转氨酶的活性无显著差异(P0.05)。结果提示,基础饲料中添加生物饲料能显著提高罗氏沼虾的增重率,增强胰蛋白酶、淀粉酶、纤维素酶、超氧化物歧化酶和谷草转氨酶的活性。     

Effects of the ruminal comminution rate and microbial contamination of particles on accuracy of in situ estimates of ruminal degradability and intestinal digestibility of feedstuffs

Effects of considering the comminution rate (k_c) and the correction of microbial contamination (using ¹⁵N techniques) of particles in the rumen on estimates of ruminally undegraded fractions and their intestinal digestibility were examined generating composite samples (from rumen‐incubated residues) representative of the undegraded feed rumen outflow. The study used sunflower meal (SFM) and Italian ryegrass hay (RGH) and three rumen and duodenum cannulated wethers fed with a 40:60 RGH to concentrate diet (75 g DM/kgBW^0.75). Transit studies up to the duodenum with Yb‐SFM and Eu‐RGH marked samples showed higher k_c values (/h) in SFM than in RGH (0.577 vs. 0.0892, p = 0.034), whereas similar values occurred for the rumen passage rate (k_p). Estimates of ruminally undegraded and intestinal digestibility of all tested fractions decreased when k_c was considered and also applying microbial correction. Thus, microbial uncorrected k_p‐based proportions of intestinal digested undegraded crude protein overestimated those corrected and k_c?k_p‐based by 39% in SFM (0.146 vs. 0.105) and 761% in RGH (0.373 vs. 0.0433). Results show that both k_c and microbial contamination correction should be considered to obtain accurate in situ estimates in grasses, whereas in protein concentrates not considering k_c is an important source of error.     

Evaluation of the safety of daily administration of capromorelin in cats

Capromorelin is a ghrelin receptor agonist that is FDA approved for appetite stimulation in dogs. The objective of this study was to evaluate the safety of daily oral administration of capromorelin to cats over a range of doses and for an extended period. Two randomized, controlled studies were conducted: in Study 1, cats (n = 6 per group) received placebo or capromorelin at a dose of 9, 15, 30 or 60 mg/kg once daily for 14 days; and in Study 2, cats received capromorelin at 6 mg/kg (n = 8) or placebo (n = 4) once daily for 91 days. Cats were evaluated using clinical observations and clinical pathology test results for both studies, with the addition of postmortem examination in Study 1 and measurements of growth hormone and insulin‐like growth factor 1 in Study 2. Abnormal clinical observations were limited to emesis, hypersalivation, lethargy/depression, head shaking and lip smacking, which occurred more frequently in the capromorelin‐treated groups than in the placebo group. There were no clinically relevant differences in clinical pathology test results between the capromorelin and placebo groups in either study.     

Top Dressing of Feed with Desiccated Chlamydospores of Duddingtonia flagrans for Biological Control of the Pre-Parasitic Stages of Ovine Haemonchus contortus

Feeding trials were conducted with stall-fed sheep parasitized with Haemonchus contortus. For 10 days they were offered 250 g of a concentrate feed that had been top-dressed with desiccated chlamydospores of Duddingtonia flagrans at 1×10⁵, 5×10⁵, 1×10⁶ or 2×10⁶ chlamydospores/kg body weight. Pooled faeces from each group on day 7 of spore feeding were spread on different pasture plots. On day 28 after the start of spore feeding, further pooled faeces from each group were spread on the same plots. The larval burdens on the plots were monitored for 2 months and the larval harvest from in vitro faecal cultures were monitored regularly. The application of 1×10⁶ or more spores/kg body weight virtually eliminated larvae from both the pasture and the faecal cultures. The application of as few as 1×10⁵ spores/kg body weight had a profound impact on larval recovery. The effect persisted while the spores were being fed but not for more than 4 days following discontinuation of spore feeding. Top dressing supplementary feed with dried chlamydospores offers a potential way of using D. flagrans for biological control of the pre-parasitic stages of H. contortus.     

氮对千日红试管苗生长和开花诱导的影响

本文以千日红组培苗为试验材料,研究培养基中氮形态及含量对千日红试管苗生长和开花诱导的影响。结果表明,1)相对于铵态氮(NH₄⁺),硝态氮(No₃^-)作为唯一氮源更有利于千日红试管苗生长和开花诱导,但千日红在NH₄⁺和NO₃^-同时存在的培养基中表现最佳。2)在20 mmol/LNH₄⁺(NO₃^-)和5 mg/L PP₃₃₃存在的条件下,试管苗生长基本随着培养基中NO₃^-(NH₄⁺)含量的增加而增加,并在含40 mmol/L NO₃^-+20 mmol/L NH₄⁺(即MS培养基中氮含量)的培养基中株高达到最大值5.91 cm;而叶片数和开花率则随着培养基中NH₄⁺和NO₃^-含量的增加呈现先增加后下降的趋势,并在20 mmol/L NO₃^-+5 mmol/LNH₄⁺培养基中达到最大值,分别为10.7片/株和38.89%。3)氮含量及形态配比结果表明,千日红试管苗开花率在培养基中氮总量为5 mmol/L、NO₃^-/NH₄⁺为4/1时达到最大值39.95%,而株高和叶片数在氮总量为35 mmol/L,NO₃^-/NH₄⁺为4/1时达到最大值8.52 cm和13.38片/株。千日红试管苗开花率与培养基中NO₃^-/NH₄⁺显著正相关,而与氮总量及株高之间显著负相关。此外,培养基中氮含量及形态配比还显著影响无菌苗根系生长。     

Prediction of Energy Digestibility of Hays in Horses

Difficulties in applying in vivo methods encourage the prediction of energy values of feeds in horses from alternative methods. Previous attempts to predict energy values from chemical composition have ignored differences among experiments. The current evaluation aimed to find the most reliable predictors (chemical composition and nutrient digestibilities) of apparent total tract energy digestibility of hays. Prediction was done with treatment means from a diverse collection of studies conducted worldwide. Experiment was included as a random effect in models to control for differences among experiments, and treatments means were weighted to account for unequal variances of the means across experiments. Organic matter digestibility (OMD; %) proved to be the most reliable (root mean square error [RMSE] = 1.6486; R² = 0.8871) predictor of gross energy digestibility (GED; %) when calculated from 44 treatment means (n) obtained from 28 experiments conducted in 16 different studies (GED = 5.527 + 0.8124 OMD). Neutral detergent fiber (NDF; g/kg dry matter) presented a single chemical entity that was preferred over any multipredictor equation (GED = 70.4638−0.0360 NDF; RMSE = 2.9462; R² = 0.6309; n = 58). However, the obtained equations should be validated against observed values, whereas alternative methods should be explored to predict OMD.     

Evaluation of Oxygen-dependent Immunodefences of the Polymorphonuclear Cells of Some Tropical Ruminants

Activation of polymorphonuclear cells (PMNs) leads to the formation of superoxide, which is in turn dismutated to H₂O₂ by superoxide dismutase (SOD) and is partly responsible for oxygen-dependent microbicidal activity. However, no comparative information is available on the effect of SOD inhibition before PMN activation to allow simulation of the SOD defects that are known to occur in some ruminants. This paper attempts to examine the degranulative and phagocytic responses in buffalo, cattle and goat PMNs exposed to diethyldithiocarbamate, a known SOD inhibitor. The activity of glutathione peroxidase and reductase was increased in the presence of SOD inhibitor. On activation, H₂O₂ production increased significantly (p<0.01), while SOD inhibition before the activation of PMNs caused a significant decline in the production of H₂O₂ (p<0.05) in all the species studied. There was a significant increase (p<0.05) in the phagocytosis of Candida albicans spores by buffalo PMNs activated with opsonized zymosan. Activation of bovine PMNs after exposure to the SOD inhibitor resulted in a significant decline (p<0.05) in phagocytic activity; in the other species, the two values only approached significance. Among the activators, opsonized zymosan caused a significant increase in phagocytic activity as compared to lipopolysaccharide, particularly in the PMNs of buffaloes (p<0.05). Increased fungicidal activity (p<0.05) occurred with opsonized zymosan-activated PMNs of all the species studied. The fungicidal activity was found to decline in PMNs exposed to SOD inhibitor before activation (p<0.05). Interestingly, the phagocytic activity of caprine PMNs was found to be lower than that of PMNs from cattle (p<0.05).     

In Vitro Evaluation of the Effects of Selected Plants on the Growth of the Mycelial Form of Histoplasma capsulatum Variety farciminosum in Ethiopia

Epizootic lymphangitis is prevalent in equines in Ethiopia, causing remarkable economic and welfare impacts but often neglected. Lack of effective treatment contributed to its continued occurrence, and hence, search for an effective treatment should be considered a priority area to minimize its impacts. Previous ethnobotanical studies have reported that Curcuma longa, Phytolacca dodecandra, and Datura stramonium were used to treat cutaneous fungal infections and reduce their incidence. The treatment effects of these plants against epizootic lymphangitis should be studied. The in vitro growth inhibitory effects of methanol extracts of the root of C. longa, berry of P. dodecandra, and leaf of D. stramonium were evaluated. Histoplasma capsulatum var farciminosum was isolated from clinical cases of epizootic lymphangitis in carthorses in central Ethiopia. The nested polymerase chain reaction was used to confirm the identity of the isolates. Serial twofold dilutions of the extract of berries of P. dodecandra and leaves of D. stramonium were done in sterile water, whereas dilution of the extract of roots of C. longa was done in dimethylsulphoxide. The effects of the plants on the growth of Histoplasma capsulatum var farciminosum were assessed by agar dilution assay. Culture media with no antifungal agent and media containing ketoconazole served as negative and positive control, respectively. The methanol extract of C. longa showed inhibitory effects at concentrations ranging from 0.07 to 5 mg/mL. Similarly, the methanol extract of P. dodecandra showed growth inhibitory effects at concentrations ranging from 0.156 to 5 mg/mL. That is, the growth inhibitory concentration of C. longa was 0.07 mg/mL, whereas that of P. dodecandra was 0.156 mg/mL. In contrast, D. stramonium showed no inhibitory effect. This preliminary observation showed that methanol extracts of C. longa and P. dodecandra showed inhibitory effects on the growth of Histoplasma capsulatum var farciminosum requiring further repeated in vitro evaluation so as to generate adequate evidence, which would justify in vivo trials.     

Effect of dietary stable isotopic ratios of carbon and nitrogen on the extent of their incorporation into tissues of rats

This study was conducted to investigate the effect of different dietary ratios of ¹³ C to ¹² C or ¹⁵ N to ¹⁴ N on their relative incorporation into tissues. Eighty male rats were used in two 21-day feeding trials in which they were fed diets with either high δ¹³C levels (δ¹³C = −13.89‰ and δ¹⁵N = 2.37‰ in experiment 1 and δ¹³C = −19.34‰ and δ¹⁵N = 4.73‰ in experiment 2) or low δ¹³C levels (δ¹³C = −17.90‰ and δ¹⁵N = 3.08‰ in experiment 1 and δ¹³C = −21.76‰ and δ¹⁵N = 0.53‰ in experiment 2), meanwhile, the dietary δ¹⁵N levels were designed to two ranks. Blood, liver, adipose and muscle tissues were collected on day 0, 3, 7, 14, and 21 for determination of ¹³ C, ¹² C, ¹⁵ N and ¹⁴ N isotopes. Rat growth rate, antioxidant capacity and metabolic parameters were also assessed. The results indicate that adipose tissue tend to deplete ¹³ C before the stable isotopic ratios achieved final equilibrium. Therefore, feeds with different isotopic signatures had different incorporation rates into tissues. Low dietary ¹³ C levels decreased tissue δ¹³C values whereas high dietary ¹³ C levels did not alter tissue δ¹³C values during the 21-d experiment. Blood δ¹⁵N values were a reliable parameter in assessing the relative contribution of dietary nitrogen to tissues. This study revealed a relationship between dietary isotopic signatures and their incorporation rates into rat tissues. However, more studies are needed to illustrate the mechanism through which dietary isotopic ratios influence the extent of isotopic incorporation into the tissues.     

The effect of low levels of dietary cobalt on the chemiluminescence response of polymorphonuclear leukocytes of goats

Twenty ten-week-old newly weaned male Batinah goats were randomly assigned to a control (n = 10) and a treated (n = 10) group and were fed a diet containing 0.1 mg/kg DM cobalt (Co). Goats in the treated group received bi-monthly subcutaneous injections of 2000 μg of hydroxycobalamin. The phagocytic function of the polymorphonuclear leukocytes (PMN) were tested using a luminol-dependent chemiluminescence assay with opsonized zymosan as the phagocytic target. One month after the onset of the experiment PMN from the control group exhibited a significantly (p < 0.05) lower CL response, which continued for the second month. The results of the present study demonstrated that low levels of dietary cobalt leads to an early impairment of phagocytic function. This may at least in part, be an explanation as to why at the field level in Oman young goats fed diets containing low levels of Co appear to be more susceptible to infections.     

海南岛红毛丹种质资源DNA指纹图谱构建

分别利用筛选出的多态性高、谱带清晰的8条ISSR标记和18对SRAP标记对海南岛69份红毛丹种质资源进行PCR扩增,8条ISSR引物共检测到425个多态性条带,其中品种(系)特异条带47个,平均位点多态性信息含量(PIC)值为0.928,可鉴别的种质资源数25～67份;18对SRAP引物共检测到894个多态性条带,其中品种(系)特异条带69个,平均位点多态性信息含量(PIC)值为0.936,可区分的种质资源数为17～63份。综合各项指标利用ISSR16和ISSR5引物21个条带用于构建红毛丹种质DNA指纹图谱,该图谱可有效区分69份红毛丹种质资源。同时该DNA指纹图谱还可为下一步红毛丹种质资源鉴定、利用、品种权保护和分子育种等提供了理论依据。