首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 312 毫秒
1.
我国粮食安全主要压力在饲料粮,破解粮食安全的重要潜力也在饲料粮。饲料资源短缺、人畜争粮矛盾日益加剧。开发非粮饲料资源和提高饲料养分利用率是缓解我国粮食安全矛盾的重大战略需求。自1864年Henneberg与Stohmann首倡的概略成分分析方法以来,饲料养分的测试方法已沿用一个半世纪,基本保持原体系未变。而针对饲料原料碳水化合物组分的复杂性和多样性,其分析方法和分析层次从Weende proximate粗纤维(概略养分分析)——van Soest洗涤纤维(范式洗涤纤维法)——总饲粮纤维法不断地演进。饲粮纤维黏性、溶解性和持水力等理化特性限制了本身以及饲粮中其它养分被单胃动物消化、吸收和利用,其抗营养作用受到饲粮结构、畜禽品种、生理阶段、环境条件等种种复杂因素的影响,同时饲粮纤维的分解产物具有重要的营养健康功能。因此,剖析饲粮碳水化合物组分和解析饲粮纤维对养分消化、吸收、利用规律至关重要。本文从饲粮纤维的定义和内涵入手,剖析饲粮碳水化合物组分的分析方法和层次的演进,分析饲粮纤维的物理化学特性及其抗营养机制,总结饲粮纤维在猪消化道利用特点,其中侧重分析了饲粮纤维水平和类型对猪饲粮能量、蛋白...  相似文献   

2.
反刍动物瘤胃产生的甲烷不仅是造成温室效应的主要原因,也造成饲粮能量的损失并降低饲粮的利用率。反刍动物瘤胃内甲烷产量与饲粮纤维组分高度相关。论文综述了反刍动物瘤胃内甲烷生成的机理,饲粮纤维组分与甲烷生成量间所建立的模型,以及饲粮纤维组分和纤维组分消化率对甲烷排放的影响,旨在揭示甲烷排放与饲粮纤维组分间关系,为甲烷减排及动物生产提供理论依据。  相似文献   

3.
鸡对纤维饲料的应用潜力   总被引:3,自引:0,他引:3  
一般认为,家禽饲粮中的纤维素和其他纤维是有害处的,尤其是对肉用仔鸡.例如,曾报道将肉用仔鸡饲粮(非颗粒状)的纤维素从0增加到20%,导致体重和饲料转化率降低,而且肉用仔鸡的所有品系对饲粮纤维素的反应几乎相同.纤维素在肉用仔鸡饲粮中差不多没有什么能量价值,而其他纤维物质的能量价值也甚低.因此,除非该种饲料给鸡提供经济的可消化养分,否则就没有什么理由在饲粮中加入纤维物质.  相似文献   

4.
李宗付  陈代文  余冰 《饲料工业》2006,27(24):24-27
试验选用324只1日龄AA肉鸡(公鸡),采用3×2因子设计,研究在不同能量水平的饲粮中添加植酸酶对肉鸡生长性能和养分利用率的影响。试验设3个能量水平(12.33、12.13、12.03MJ/kg)和2个酶水平(0、500FTU/kg),共计6个处理组,每个处理组6个重复,每个重复9只鸡,试验期42d。结果表明:饲粮添加植酸酶显著(P<0.05)或极显著(P<0.01)提高了肉鸡日增重、采食量,改善了饲料利用率,提高了干物质、粗蛋白、钙、磷的利用率,但对能量利用率没有明显影响(P>0.05);降低饲粮能量水平极显著降低了肉鸡对干物质、能量、钙的利用率(P<0.01),显著降低了其对磷的利用率(P<0.05),但对生产性能和粗蛋白利用率没有显著影响(P>0.05);植酸酶和能量对肉鸡饲料利用率、干物质和钙的利用率存在显著的交互作用(P<0.05),表现为处理2组能量水平条件下添加植酸酶在生长性能和养分利用率上改善幅度最大,表明植酸酶在适宜降低能量水平的饲粮中的作用效果更好。试验中,以能量水平为12.13MJ/kg的肉公鸡饲粮中添加500FTU/kg植酸酶(处理5组)为最佳组合。  相似文献   

5.
近几十年来,人们通过改进饲料的加工方式以及使用外源性饲料添加剂,提高了猪对植物性饲料的利用率。本文阐述了纤维的特征及其对猪日粮纤维利用率的影响、日粮纤维对猪胃肠道生理状态、能量及营养利用率的影响、机械加工对饲料纤维、能量利用率的影响以及日粮中添加外源性酶类对育肥猪的影响,以期为研发降低纤维含量、提高能量利用率或采食量的加工技术,探索相关酶类,提高猪养殖行业的经济效益提供借鉴和参考。  相似文献   

6.
植酸酶可解除植酸对饲料Ca、P、Mg、Fe、Mn、Zn、淀粉、蛋白质、胃肠道蛋白酶、淀粉酶等的螯合作用,提高养分利用率,但植酸酶对猪饲粮能量利用率的影响目前结论还不明确,笔者就该问题进行了综述。  相似文献   

7.
本试验研究了0~6周龄贵州黄鸡的能量需要,旨在为贵州黄鸡的科学养殖和制定其饲养标准提供理论依据和数据参考。采用单因素完全随机试验设计,选取健康1日龄贵州黄鸡雏鸡400只,随机分为4组,每组5个重复,每个重复20只鸡。4组试验鸡饲粮能量水平分别为10.03、11.71、12.54和13.16 MJ/kg,试验期为6周。通过饲养试验,测定每周的体重和采食量,计算平均日增重、平均日采食量和料重比;通过代谢试验,测定表观代谢能及养分表观代谢率;通过比较屠宰试验,测定鸡体能量、粗蛋白质和粗脂肪含量,计算鸡体能量、粗蛋白质和粗脂肪沉积率,确定饲粮适宜能量水平。结果显示:饲粮能量水平对0~6周龄贵州黄鸡的平均日增重、平均日采食量和料重比均有显著影响(P<0.05),对平均日增重进行二元回归分析得到最适饲粮能量水平为11.17 MJ/kg。饲粮能量水平对0~6周龄贵州黄鸡的各养分表观代谢率均有显著影响(P<0.05),适当提高饲粮能量水平可以提高各养分的表观代谢率,进而提高饲料利用率。以此为判定指标,推荐0~6周龄贵州黄鸡饲粮能量水平为12.54 MJ/kg。饲粮能量水平对0~6周龄贵州黄...  相似文献   

8.
日粮纤维对猪饲料能值评定的影响   总被引:1,自引:0,他引:1  
日粮纤维为结构性与非结构性多糖和木质素的总称。猪对日粮纤维的消化随日粮纤维来源和组分不同而存在差异。随体重和年龄的增加,猪对日粮纤维消化能力提高,成年母猪对日粮纤维利用率最高。对高日粮纤维饲料至少要提供2个能量值:一个对生长猪,一个对成年母猪。日粮纤维对猪能量供应的实际效果受到环境温度或动物行为变化的影响。  相似文献   

9.
自配饲粮是广大农村养殖场(户)降低饲料生产成本,增加效益的一条有效途径。在自配饲粮中,除了要求日粮的能量、粗蛋白、钙、磷等养分平衡外,还应考虑日粮中的氨基酸的平衡,否则将会影响饲料中蛋白质的利用率,造成生产成本提高、生产性能下降、效益降低等后果。在没...  相似文献   

10.
本试验旨在研究粗饲料组合对奶牛饲粮养分消化率、能量和氮的利用的影响.试验采用单因素随机区组设计,将16头体重、年龄、胎次相近的,处于干奶期的健康荷斯坦奶牛分为4组,每组4头.以常用的粗饲料设计A(玉米青贮+玉米秸秆)、B(玉米青贮+羊草)、C(玉米青贮+玉米秸秆+羊草)、D(玉米青贮+苜蓿草+羊草)4种粗饲料组合的饲粮.结果表明:饲粮D干物质、有机物和中性洗涤纤维的消化率最高,显著高于其他各饲粮(P<0.05),其次为饲粮B和饲粮C,饲粮A最低,显著低于其他各饲粮(P<0.05),各饲粮的酸性洗涤纤维消化率差异不显著(P>0.05).粗饲料组合显著影响饲粮摄入总能、能量消化率和能量代谢率(P<0.05),饲粮D甲烷能占摄入总能比显著低于其他3种饲粮(P<0.05).各饲粮的粪氮、尿氮占摄入总氮比差异不显著(P>0.05),饲粮D的氮消化率显著高于饲粮B与饲粮C(P <0.05),且饲粮B显著高于饲粮A(P <0.05);饲粮B、饲粮D的氮利用率显著高于饲粮A(P <0.05).由此可见,玉米青贮+苜蓿草+羊草型饲粮的养分消化率、能量和氮的利用均优于其他各饲粮,羊草与玉米秸秆之间存在正组合效应,两者搭配使用可提高玉米秸秆的消化率,优化能量和氮的利用.  相似文献   

11.
Sanguinarine (SA) is a benzo[c] phenanthridine alkaloid which has a variety of pharmacological properties. However, very little was known about the pharmacokinetics of SA and its metabolite dihydrosanguinarine (DHSA) in pigs. The purpose of this work was to study the intestinal metabolism of SA in vitro and in vivo. Reductive metabolite DHSA was detected during incubation of SA with intestinal mucosa microsomes, cytosol, and gut flora. After oral (p.o.) administration of SA, the result showed SA might be reduced to DHSA in pig intestine. After i.m. administration, SA and DHSA rapidly increased to reach their peak concentrations (Cmax, 30.16 ± 5.85, 5.61 ± 0.73 ng/ml, respectively) at 0.25 hr. Both compounds were completely eliminated from the plasma after 24 hr. After single oral administration, SA and DHSA rapidly increased to reach their Cmax (3.41 ± 0.36, 2.41 ± 0.24 ng/ml, respectively) at 2.75 ± 0.27 hr. The half-life (T1/2) values were 2.33 ± 0.11 hr and 2.20 ± 0.12 hr for SA and DHSA, respectively. After multiple oral administration, the average steady-state concentrations (Css) of SA and DHSA were 3.03 ± 0.39 and 1.42 ± 0.20 ng/ml. The accumulation indexes for SA and DHSA were 1.21 and 1.11. The work reported here provides important information on the metabolism sites and pharmacokinetic character of SA. It explains the reasons for low toxicity of SA, which is useful for the evaluation of its performance.  相似文献   

12.
13.
14.
The prevalence of Salmonella in fresh pork cuttings in Denmark in the years 2002 and 2006 was investigated at retail and compared with the retail supply pattern. A total of 1025 and 3473 samples were taken in 2002 from butcher's shops and supermarkets, respectively. The corresponding numbers in 2006 were 259 from butchers' shops and 628 from supermarkets. In 2002, 1.2% of all samples were positive for Salmonella; butchers' shops and supermarkets had 1.8% and 1.0% positive samples, respectively. The overall prevalence in 2006 was 4.2%, with prevalence of 8.1% and 2.6% for butchers' shops and supermarkets, respectively. Hence, increases around 3- to 5-fold were found. There was neither observed any parallel increase in Salmonella positive carcasses in Danish slaughterhouses during the study period, nor were any changes in supply routes towards slaughterhouses with higher prevalence observed, which could explain the apparent increase. We hypothesize that hygiene levels and ability to avoid cross-contamination and prevent growth of the organism, in the meat processing chain after slaughter were the most likely responsible factors. Results from this study indicate that the hygiene performance, particularly at retail, has a significant impact on the occurrence of Salmonella. This implies that there is no direct link between slaughterhouse Salmonella surveillance data and the level of Salmonella contamination at retail. To improve risk assessment of Salmonella in fresh pork meat, this study underlines the need for comprehensive retail data.  相似文献   

15.
Bartonella and Babesia infections and the association with cattle breed and age as well as tick species infesting selected cattle herds in Taiwan were investigated. Blood samples were collected from 518 dairy cows and 59 beef cattle on 14 farms and 415 ticks were collected from these animals or in a field. Bartonella and Babesia species were isolated and/or detected in the cattle blood samples and from a selected subset (n = 254) of the ticks either by culture or DNA extraction, PCR testing and DNA sequence analysis. Bartonella bovis was isolated from a dairy cow and was detected in 25 (42.4%) beef cattle and 40 (15.7%) tick DNA samples. This is the first isolation of B. bovis from cattle in Asia and detection of a wide variety of Bartonella species in Rhipicephalus microplus. Babesia spp. were detected only on one farm from dairy cows either infected by Babesia bovis (n = 10, 1.9%) or B. bigemina (n = 3, 0.6%).  相似文献   

16.
17.
Commercial feedstuffs are a basic element in modern pet husbandry in the world. In dogs, the effect of mycotoxins is severe and can lead to death. Few reports on the influence of dietary mycotoxins were found in the scientific literature. The aims of this work were to isolate and identify the mycoflora and to determine the aflatoxins (AFs) natural occurrence in raw materials and ready dry pet food. Therefore, the aflatoxigenic capacity of Aspergillus flavus species was investigated. Aspergillus was the prevalent genera (65-89%) followed by Penicillium and Fusarium spp. Aspergillus flavus was the most prevalent species, followed by Aspergillus sydowii, Aspergillus fumigatus and Aspergillus versicolor. Aspergillus flavus frequencies ranged from 58% to 86% except in sorghum meal. All samples assayed (except corn grains and ready pet food) showed Fusarium spp. contamination. Corn meal and corn meal and gluten samples had 100% Fusarium verticillioides. Fusarium graminearum was isolated from sorghum meal. Aspergillus flavus strains (75%) isolated from raw materials and 57% from pet food were able to produce AFs. All samples showed AFs contamination percentages over 70%; corn and sorghum meal obtained the highest AFs levels. Ready pet food did not show quantitative levels of the tested toxins. This is the first report of the aflatoxigenic capacity by A. flavus from Brazilian pet food.  相似文献   

18.
Rectal swabs were collected from 437 household and 491 stray dogs in northern Taiwan from May 2003 to June 2005 to investigate the prevalence and antimicrobial susceptibilities of salmonellae and campylobacters. The results revealed that 2.1% of household dogs and 6.3% of stray dogs were positive for salmonellae, with Salmonella Duesseldorf being the most dominant serotype in both. Additionally, 2.7% of the household dogs and 23.8% of the stray dogs were positive for campylobacters. Campylobacter jejuni was the most prevalent species (86.8%), followed by C. upsaliensis (9.3%) and C. coli (3.9%). Both salmonella and campylobacter isolation rates from the stray dogs were significantly higher than those from the household dogs (p < 0.01). The susceptibility of 33 C. jejuni isolates to eight antimicrobials was studied by the E-test. A high rate of resistance was observed to azithromycin (93.9%), clindamycin (87.9%), erythromycin (81.8%), tetracycline (78.8%), chloramphenicol (69.7%), nalidixic acid (51.5%), gentamicin (33.3%), and ciprofloxacin (18.2%). The susceptibility of 40 Salmonella isolates to 15 antimicrobials was also studied by the disc-diffusion method. All the Salmonella isolates were susceptible to ciprofloxacin and ceftriaxone. Resistance was observed most frequently to tetracycline (77.5%), chloramphenicol (52.5%), and ampicillin (50%).  相似文献   

19.
Helminth and protozoan parasites in dogs and cats in Belgium   总被引:1,自引:0,他引:1  
This study investigates the level of helminthic and protozoal infestation over the last 10 years in strays, well-cared-for dogs and cats. Determination of the prevalence of infections was based either on faecal examination or on worm counts at necropsy. Of 2324 faecal flotations (NaCl sp.gr. 1.20) of stray dogs, 34.2% had eggs or proglottids of one or more worm species consisting of Toxocara canis (17.4%), Toxascaris leonina (10.1%), Uncinaria stenocephala (11.4%), Trichuris vulpis (7.0%) and cestodes (2.1%). Isospora oocysts were observed in 5.2% of the dogs. The data on the distribution of the various worm species in the positive dogs indicate that T. canis eggs were by far the most common (50.9%). Necropsy data from 212 infected dogs indicate that 38.9% were infected with T. canis and 33.7% with T. leonina. The overall prevalence of worm infestation of 246 well-cared-for kennel dogs, based on worm egg counts by the McMaster technique, was 36.1%. Of 30 feline faecal samples examined by flotation, 83.3% were positive for parasites, including Toxocara cati (60%), Ancylostoma tubaeformae (36.6%), Taenia (Hydatigera) taeniaeformis (20%) and coccidia (30%). Toxocara cati was the most frequently found worm species at the necropsy of 25 cats (52%). Toxoplasma was not observed.  相似文献   

20.
Chlortetracycline hydrochloride was administered intra-arterially (11 mg/kg) and as an oral drench (33 mg/kg) to ten 21.0-31.5-kg pigs. Five of the pigs were fasted 18 h prior to dosing and five of the pigs were fed ad libitum prior to dosing. The mean volume of distribution determined by area-under-the-curve calculations for the fasted pigs (0.967 +/- 0.210 l/kg) was significantly less (P less than 0.05) than the mean volume of distribution for the fed pigs (1.39 +/- 0.31 l/kg). Mean total body clearance of the drug was also significantly less (P less than 0.05) in the fasted pigs (0.165 +/- 0.055 l/kg/h) as compared to the fed pigs (0.307 +/- 0.053 l/kg/h). The elimination constants (beta) were not found to be statistically different (P less than 0.05): 0.1811 +/- 0.0057 for the fasted pigs; 0.2260 +/- 0.0461 for the fed pigs. The bioavailability for both groups was similar; 19.12 +/- 8.3% for the fasted pigs and 17.88 +/- 5.3% for the fed pigs. In a second experiment three groups of six pigs which weighed 34.5-44.1 kg were fed a corn-soy diet ad libitum. The rations were fortified with chlortetracycline at 100, 400 or 1000 mg chlortetracycline hydrochloride/kg feed. Chlortetracycline concentrations were determined in plasma samples collected over a 6-day period. Plasma chlortetracycline concentrations reach a plateau within 24 h after initial access to the trial diets and were highly correlated with the dose of the drug consumed (r2 = 0.97).  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号