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41.
A study was conducted to characterize the cattle production systems in Nyagatare District, Eastern Province of Rwanda using pre-tested questionnaires, interviews with key informants as well as focus group discussions in a period of 2 months. The respondents were selected by multi-stage sampling at sector and cell levels. Based on the procedure of Krejcie and Morgan (Educational and Psychological Measurement 30:607–610, 1970) to determine the overall sample size, the result indicated that the majority (98.3%) of farms were privately owned by large families of five to seven members, and most farmers (53.9%) had only primary education. Most respondents (52.6%) were in the age bracket of 41–50 years and were mainly (48.3%) located within 3 km from trading centers. The farm size averaged 6.5 ± 0.8 ha and most farms (64.7%) were fenced except in Rukomo Sector (50%) where zero grazing prevailed. Natural pastures (savanna grass land) were the main feed resource; tethering (9%) and communal grazing had diminished. Napier grass was the main planted forage (93.2%), followed by Chloris guyana (3.1%) and Brachiara (1.2%). Leguminous forages were rarely (2.5%) reported. Vita-mineral and salt block supplements, hay, and crop residues were the predominant supplementary feed stuffs used except in Karangazi and Rwemiyaga Sectors where only vita-mineral block predominated. However, maize and rice brans were reported to be the main feed stuffs used in supplementary feeding of lactating cows. Most farmers (89.7%) reported shortage of water as most of the farmers trekked their cattle to the nearest valley dams (59.2%), rivers (21.1%), and a few 6% had water on farms. Indigenous cattle were predominant (67.03%) followed by cross-breeds (28.37%) and exotics (4.6%) while all farmers kept small ruminants. Natural breeding predominated (74.9%) and most farms (60.6%) had animal houses most of which were temporary (52.8%). The reported mean age at first calving (AFC) was highest (40.2 ± .33) for Ankole and the lowest (29.1 ± .50) months for exotic cattle. Calving interval was shorter in local breeds than 65.7 ± 3.0 in exotic. The mean dairy milk yield was lowest for Ankole cattle 2.4 ± .08 as compared to the exotics (10.42 ± .36) and their crosses (7.2 ± .34). The main challenges were diseases, shortage of water, feeds, and inadequate extension services. Same observation was reported by Okello (African Journal of Range and Forage Science 22(3), 2005) in Uganda.  相似文献   
42.
Mesenchymal stem cells are undifferentiated cells that have the ability to divide continuously and tissue regeneration potential during the transplantation. Aging and loss of cell survival, is one of the main problems in cell therapy. Since the production of free radicals in the aging process is effective, the use of antioxidant compounds can help in scavenging free radicals and prevent the aging of cells. The aim of this study is evaluate the effects of L-carnitine (LC) on proliferation and aging of rat adipose tissue-derived mesenchymal stem cells (rADSC). rADSCs were isolated from inguinal region of 5 male Rattus rats. Oil red-O, alizarin red-S and toluidine blue staining were performed to evaluate the adipogenic, osteogenic and chondrogenic differentiation of rADSCs, respectively. Flow cytometric analysis was done for investigating the cell surface markers. The methyl thiazol tetrazolium (MTT) method was used to determine the cell proliferation of rADSCs following exposure to different concentrations of LC. rADSCs aging was evaluated by beta-galactosidase staining. The results showed significant proliferation of rADSCs 48 h after treatment with concentrations of 0.2 mM LC. In addition, in the presence of 0.2 mM LC, rADSCs appeared to be growing faster than control group and 0.2 mM LC supplementation could significantly decrease the population doubling time and aging of rADSCs. It seems that LC would be a good antioxidant to improve lifespan of rADSCs due to the decrease in aging.  相似文献   
43.
应用灰色系统理论评价草地质量初探   总被引:14,自引:3,他引:14  
以草地优良牧草产量、可食牧草产量、载畜量、牧草利用率和覆盖度为主要指标,应用灰色系统理论中关联工分析的方法,对武威地区32个类型草地质量进行了评价。结果表明,质量最好的草地是山地草甸,质量最关的是干荒漠和荒漠摹。根据分析结果,提出了武威地区草地质量分级的方案。  相似文献   
44.
Livestock production is an integral part of the rain-fed and irrigated agriculture system in Pakistan. Animal production is closely interlinked with the cropping systems and play a crucial role in the rural economy. Participatory rural appraisals and economic opportunity surveys were conducted in two ecological zones (irrigated and rain-fed) and two dairy production systems (peri-urban and mixed livestock). Major constraints in animal health, nutrition and reproduction were identified and interventions were suggested to overcome these difficulties. The economic opportunity survey revealed that maximum opportunity to enhance farmers’ income is to increase milk production per day per animal, which can be accomplished through coordinated improvements in nutrition, reproduction and genetics.  相似文献   
45.
粮草兼顾型畜牧业饲草料发展现状及展望   总被引:1,自引:0,他引:1  
随着我国人口数量的持续增长,居民生活水平不断提高,粮食需求随之剧增,肉、蛋、奶等畜禽产品的消费也不断增长,人们对畜产品的需求决定着农业发展的方向。本文介绍了我国粮草兼顾型畜牧业发展的主要背景,简述了传统畜牧业和粮草兼顾型畜牧业对饲草料需求的异同,并分析了新形势下我国畜牧业发展的方向:1)针对我国居民膳食结构改变对农业结构发展模式的影响,提出现阶段发展草地农业,进行广泛的系统耦合是促进农业可持续发展的技术保障,是我国农业结构调整的必然之路;2)结合我国现阶段畜牧业发展现状,指出将牧草或其他饲料作物的生产利用纳入到农业生产体系当中,通过粮―草―畜有机结合,建立起土地―植物―动物产品完整的产业链条来满足消费者食物需求;3)建议通过增加优质牧草日粮比例、发展草食家畜、建设信息自动化等具体措施,来促进、引领和保证粮草兼顾型畜牧业的可持续发展。  相似文献   
46.
紫花苜蓿人工草地施肥试验   总被引:1,自引:0,他引:1  
在辽宁西部坡地上进行紫花苜蓿不同施肥处理试验,经过1年的研究结果表明,在苜蓿人工草地上无论是单一施用氮肥还是复合肥,均可有效地提高牧草产量并取得较为明显的经济效益,其中以每亩施用尿素15 kg和25 kg效果最好,效益最高,每亩可增经济效益分别是40.74元和40.63元。  相似文献   
47.
48.
The objective of this study was to analyse the effects of different levels of rumen-degradable protein (RDP) on intake, digestibility and microbial protein synthesis by supplementing mustard oil cake (MOC) on rice straw-based diet of cattle (Bos indicus) in Bangladesh. A 4 × 4 Latin square design was applied. Four diets having constant energy (7.0 MJ/kg of dry matter (DM)) with varying levels of RDP (M 0 = 4.1 g/MJ (control), M 1 = 6.3 g/MJ, M 2 = 8.3 g/MJ and M 3 = 12.4 g/MJ of metabolizable energy (ME)) were received by each animal for a period of 28 days. A metabolism trial was conducted for 7 days. Results indicate that with increasing levels of RDP, crude protein (CP) and RDP intake increased significantly (P < 0.01). The significant (P < 0.01) increase in digestibility values are obtained for DM, organic matter, CP and digestible organic matter in the rumen. The digestibility of neutral detergent fibre and acid detergent fibre was also increased significantly (P < 0.05). The total nitrogen (N), ammonia-N and total volatile fatty acids increase significantly (P < 0.01) while the rumen pH increased from M 0 to M 2 and decreased thereafter. The efficiency microbial N intake increased significantly (P < 0.01) but showed a curvilinear response with higher RDP level (12.40 g/RDP/MJ ME). This study concludes that supplementation of RDP from MOC enhances the intake, digestibility and microbial protein synthesis which ultimately increases utilization of low-quality feed resources that can be used for developing cost-effective feeding systems on a straw-based diet in tropical regions.  相似文献   
49.
Indigenous chicken (IC) and their production systems were characterized to understand how the whole system operates for purposes of identifying threats and opportunities for holistic improvement. A survey involving 594 households was conducted in six counties with the highest population of IC in Kenya using structured questionnaires. Data on IC farmers’ management practices were collected and analysed and inbreeding levels calculated based on the effective population size. Indigenous chicken were ranked highest as a source of livestock income by households in medium- to high-potential agricultural areas, but trailed goats in arid and semi-arid areas. The production system practised was mainly low-input and small-scale free range, with mean flock size of 22.40 chickens per household. The mean effective population size was 16.02, translating to high levels of inbreeding (3.12%). Provision for food and cash income were the main reasons for raising IC, whilst high mortality due to diseases, poor nutrition, housing and marketing channels were the major constraints faced by farmers. Management strategies targeting improved healthcare, nutrition and housing require urgent mitigation measures, whilst rural access road network needs to be developed for ease of market accessibility. Sustainable genetic improvement programmes that account for farmers’ multiple objectives, market requirements and the production circumstances should be developed for a full realization of IC productivity.  相似文献   
50.
A study was undertaken from October 2006 to March 2007 to determine the prevalence and antimicrobial resistance patterns of Salmonella serovars. Liver, mesenteric lymph nodes, intestinal content, and carcass swab samples (each n?=?186) were collected from 186 apparently healthy slaughtered cattle at Bahir Dar abattoir. Bacteriological analysis was done according to the International Organization for Standardization (ISO 6579 2002). Isolates were serotyped at Agence Française de Securite Sanitaire des Aliments, Cedex, France. Twenty-eight isolates consisting of Salmonella Typhimurium, Salmonella Newport, Salmonella Haifa, Salmonella Heidelberg, Salmonella Infantis, and Salmonella Mishmarhaemek were identified. Salmonella Typhimurium and Salmonella Newport were most frequently isolated while Salmonella Heidelberg and Salmonella Mishmarhaemek were isolated least. Eleven of the 28 (39.3%) were resistant to one or more of the antimicrobials tested. Resistance was shown to ampicillin, chloramphenicol, gentamycin, norfloxacin, polymyxin-B, streptomycin, tetracycline, and trimethoprim. Four of 11 (36.4%) were multiple antimicrobial resistant. All the isolates tested were susceptible to the antimicrobial effects of gentamycin, norfloxacin, and trimethoprim. Eleven, four, and two isolates of the 28 were resistant to streptomycin, tetracycline, and ampicillin, respectively. All isolates of Salmonella Infantis, Salmonella Typhimurium (except one), and Salmonella Mishmarhaemek were susceptible to the tested antimicrobials. One Typhimurium isolate was resistant to chloramphenicol, streptomycin, and tetracycline. Salmonella Haifa was multiply antimicrobial resistant to ampicillin, tetracycline, and streptomycin. All isolates of Salmonella Heidelberg were resistant to streptomycin. Results of this study indicated high level of carcass contamination with antimicrobial-resistant Salmonella serovars which could pose public health risk; suggests need for hygienic slaughtering operations and proper cooking of meat before consumption. Further detailed studies involving different abattoirs, animal products, food items, and animals on different settings were recommended in the study area.  相似文献   
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