Effects of a meal feeding regimen and the availability of fresh alfalfa on growth performance and meat and bone quality of broiler genotypes

1. The aim of this study was to identify a feeding regimen that encourages good pasture use in slow (SG) and fast (FG) growing broiler genotypes under free-range management.

2. SG and FG birds fed on either an ad libitum (ADB) or a meal feeding (MEF) programme were given free outdoor access with or without fresh alfalfa from day 22 to 72 and from day 22 to 45, respectively. In two consecutive trials, 800 birds of each genotype were included in a factorial design using groups of 40 birds replicated 5 times.

3. Fresh alfalfa consumption did not improve growth performance and meat quality attributes, whereas the feeding regimen had significant implications. When compared with their ad libitum-fed counterparts, meal-fed birds showed a significantly lower body weight at a considerably lower feed consumption rate, leading to a more favourable feed conversion ratio (FCR) during the course of the experiment.

4. The MEF regimen with a strong feed limitation significantly increased crop and gizzard weight in both genotypes. In FG birds, water holding capacity, drip loss, cooking loss and pH 45 in the breast and thigh meat were adversely affected by MEF; however, feed restriction demonstrated benefits with significant decreases in muscle fat accumulation. In SG birds, decreases in protein and dry matter content of the breast and thigh muscle with meal feeding were conclusive.

5. In both genotypes, there was no treatment-related effect on meat yield, mineral composition of the meat or bone mechanical properties.

6. In conclusion, MEF, irrespective of alfalfa intake, may provide a viable method to decrease FCR; it may be able to contribute to the production of chickens with lean carcasses but it was not capable of improving overall meat quality.     

河北省原奶质量安全现状、问题和对策

奶制品是人们的日常消费品,其质量安全,尤其是原奶的质量关系亿万民众的生命和健康。通过对河北省奶牛养殖小区的实际调查走访,发现河北省原奶质量安全控制中存在饲养环境差,奶牛饲养规模小,饲养管理水平低,养殖小区管理秩序混乱,原奶的收购检测落后等问题。文章立足实际调研,提出改善饲养环境,发展养殖小区,加强技术指导,加强养殖小区管理,加快原奶收购标准的修订等对策。     

乡村振兴战略与共享经济模式探析——以海南共享农庄为例

农业共享经济是共享经济在农业领域的重要探索。海南共享农庄建设,以乡村振兴战略为背景,以农业共享发展为思路,将城乡生产要素有机结合,推动农业产业链的延伸和农业经济发展质量的提高。在总体规划的基础上,为了适应不同地区发展的需要,海南共享农庄设计出了个人定制式、综合开发式和体验式等多种微观模式。这些模式将地区农业发展优势融入农庄建设过程,激发了农业共享经济的发展潜力。研究表明,共享农庄的建设对海南经济社会发展具有重大现实意义。共享农庄建设加快了美丽乡村建设,促进了城乡融合发展、优化了乡村治理模式、创新了精准扶贫模式,是实现乡村振兴的重要推手。     

The short- and long-term impacts of the COVID-19 pandemic on family farms in China – Evidence from a survey of 2 324 farms

Family farms are considered the most desirable form of Chinese agriculture. Studies on the risk management of family farms are rare, while the COVID-19 pandemic provides an opportunity to explore how family farms respond to risks. Based on an online survey of 2 324 family crop farms, we examine for the first time the short-term impact (immediate impact or short-term fluctuation, and farms' instantaneous response) and long-term impact (on farms' future or long-term production) of the COVID-19 pandemic on family farms' production and operation in rural China. By using factor analysis and dummy variable regression, we find that the severity of the pandemic, the lockdown of the village, and farmers' knowledge of the pandemic contribute significantly to the short-term impact, but not on the long-term impact. Farmers' characteristics such as gender, age, and education are not related to the short-term impact, but family farms with male owners or owners with high school education or below are more likely to be diversified and large-scale. The number of years the farm has existed for and agricultural insurance affect both short-term and long-term impacts. We suggest that the government needs to pay more attention to stability-enhancing policies, the market environment, vocational training and the agricultural insurance market.     

养猪废水处理工艺对耐药基因迁移影响研究进展

生猪养殖是环境中抗生素耐药基因（antibiotic resistance genes,ARGs）的重要来源之一,而养猪废水的排放是ARGs进入环境的主要渠道。目前,养猪废水中ARGs排放所导致的环境效应尚不明晰,同时,不同养猪废水处理工艺对于ARGs去除的相关研究尚处于起始阶段,需要进行更加深入、细致的研究,以及探索减少养猪废水中ARGs丰度的养殖废水处理方法。本文综述了养猪场内ARGs从产生到进入环境的过程以及当前ARGs污染情况和研究现状,从不同的污水处理法（厌氧生物处理法、好氧生物处理法、物理化学法、人工湿地法）出发,重点介绍养猪场污水处理工艺中ARGs的分布和去除效果,认为物理化学法是消减养猪废水中ARGs污染问题最具前景的处理方式。最后,基于目前养猪废水处理工艺在去除ARGs存在的不足,提出了优化处理工艺措施并强化各工艺间ARGs监测的可行性建议。     

农垦植胶企业的经济外部性分析

以经济外部性理论为依据,从天然橡胶生产成本角度出发,通过对云南和海南的国有与民营橡胶的成本比较,探讨了农垦植胶企业的经济外部性,认为衣垦企业对于当地农村经济的发展具有较强的经济外部性,有利于解决当地"三农"问题。     

Milk production systems in Central Uganda: a farm economic analysis

The Ugandan dairy sector is developing rapidly over recent years and is dominated by small-scale farmers owning more than 90 percent of the national cattle population. Due to market forces and higher competition for production factors, milk production systems are intensifying, necessitating proper understanding of the new production tendencies. Three intensive and four extensive production systems were identified and analysed, using TIPI-CAL (Technology Impact Policy Impact Calculations model). The results show that the production systems are very different in many respects but share similar development trends. Whereas intensive systems use graded animals and invest heavily into feeding, buildings and machinery, extensive systems use local breeds and invest minimally. Total cost of milk production falls with increasing herd size, while dairy returns vary among farms from 18 to 35 USD/100 Kg of milk. All systems make an economic profit, except the intensive one-cow farm, which heavily employs family resources in dairying. Due to better management of resources and access to inputs and markets, dairy farming closer to urban areas and using improved breeds is highly profitable, especially with larger herd sizes. Stakeholders should favour such practices as well as others which can improve productivity, especially in African countries where traditional systems dominate dairying.     

新疆玛纳斯河流域绿洲耕地扩张差异与驱动力研究

新疆现代绿洲是两种不同经营模式(兵团农场耕作和地方家庭承包)下团镇绿洲耕地长期扩张的真实写照。本文以玛纳斯河流域石河子垦区144团与玛纳斯县兰州湾镇为例,首先基于1958—2018年的6期影像数据,采用土地利用动态变化度,分析了团镇耕地的扩张过程;进而采用多元逐步回归等方法,分析了兵团与地方绿洲扩张的驱动力;最后从全流域绿洲扩张的角度出发,结合绿洲扩张模型,测算了绿洲耕地的适宜规模。结果表明:144团与兰州湾镇的耕地面积均大幅增加,扩张的耕地主是由草地、林地转化而来;兵团耕地扩张的核心驱动因子为节水灌溉面积、水资源径流量、农牧业平均收入;地方则为人均GDP、农牧业平均收入、农业生产总值。流域的耕地面积远超适宜规模,生态安全隐患已经凸显。建议流域的各级政府遵循"山水林田湖草生命共同体"的理念和建设要求,统筹推进流域的综合开发;加快构建现代土地资源管理制度体系,科学划定生态红线,严格限定绿洲的扩张规模,促进兵团与地方的土地利用结构优化;坚持最严格水资源管理制度,"以水定地",实现水资源高效利用,防控沙漠化对绿洲的威胁;推行土壤退化治理与土地整治相结合,提高土地利用效率和潜力,从而实现绿洲耕地的数量、质量、生态三位一体保护。