The determinants of detecting veterinary drug residues: Evidence from shrimp farmers in southern Viet Nam

While export-oriented shrimp farming has become an important source of income for many small-scale farmers in developing countries, the rate at which products are rejected at the ports of developed countries has remained high mainly due to the overuse of antibiotics. To reveal what determines the overuse of antibiotics, we interviewed 201 shrimp farmers in Viet Nam in 2015 and collected shrimp samples from each household’s pond for the screening of residual drugs. These tests revealed that residual drugs exceeding acceptable limits by Japanese standards were found in the samples of 40 farmers. We conducted cross-sectional Logit and Tobit regressions to examine whether results of the residue tests are significantly associated with farmers’ characteristics and management practices. This study finds that: (1) receiving BMP training has a significant and positive effect on reducing residual drugs; (2) if farmers know multiple extension officers, these relationships have significant and positive effects on reducing residual drugs; and (3) farmers with experience of shrimp disease outbreaks reduce use of antibiotics. Overall, this study contributes to revealing the determinants of detecting veterinary drug residues in shrimp farming in multiple (social, economic and psychological) dimensions.     

食用稻米米饭质地及适口性的研究

 通过对米饭压缩及拉伸应力曲线的测定及研究,确定了米饭硬性、松弛性、凝聚性、粘附性、粘度等5个质地指标的表达式,并对籼（36份）、粳（30份）的米饭质地指标与感官评分作了相关分析和回归分析。结果表明,籼、粳稻的米饭适口性与用Instron测得的米饭的硬性、凝聚性呈极显著负相关,与松弛性、粘附性、粘度呈极显著正相关,籼、粳米饭质地5项指标对适口性的回归方程的决定系数分别为0.673和0.630,达极显著水平;运用所建立的回归方程对籼（6份）、粳（14份）的适口性得分进行预测,预测得分与感官评分的相关性分别达显著、极显著水平。多重比较分析结果表明在区别米饭适口性优劣时,米饭质地指标较直链淀粉含量、胶稠度更具有参考价值。     

Mapping Quantitative Trait Loci for Palatability of Milled Rice

Quantitative trait loci (QTLs) controlling palatability in rice were identified using a set of 98 backcross inbred lines (BILs) population derived from a cross between a japonica variety Nipponbare and an indica variety Kasalath. The palatability scores of the population measured by RQ1/Plus Rice Analyzer, showed a continuous and transgressive segregative distribution with a range from 66 to 92. Four putative QTLs for palatability, qPAL-5, qPAL-7, qPAL-8a and qPAL-8b, were detected on chromosome 5, 7 and 8, and they accounted 7.83, 7.03, 11.58 and 7.19% of the total phenotypic variation, respectively. Three alleles qPAL-5, qPAL-7 and qPAL-8b from Kasalath increased the palatability score, whereas only one Nipponbare allele qPAL-8a increased the score. Eight transgressive lines in palatability were selected to make a comparison between phenotypic and genotypic classes. The result explained the possibility of positive QTLs pyramiding through marker-assisted selection of highly palatable rice.     

煮饭水质结合加水量和浸泡时间对粳稻食味的影响

以津川1号和津原E28为材料,采用自来水和纯净水煮饭,通过米饭感官评价和质地测定,明确水质对其食味的影响,同时研究这种影响是否与煮饭时的加水量和浸泡时间有关。结果表明,随加水量的增加,米饭外观、饭香、味道和综合评价感官得分先增大后减小,米水质量比为1:1.50时上述指标得分最高,食味最好;米水质量比在1:1.25~1.50范围内,用纯净水蒸煮的米饭的味道和粘度感官得分要高于用自来水蒸煮的米饭。随煮饭加水量的增加,米饭的硬度下降、粘度增加,与感官评价结果一致。随大米浸泡时间延长,米饭外观、味道、粘度和综合评价感官得分先增加后减小,浸泡1.0 h,上述指标得分最高,食味最好。浸泡时间延长会降低米饭的饭香。在浸泡时间15.0 h内,与用自来水浸泡后蒸煮相比,用纯净水浸泡后蒸煮的米饭食味感官综合评价更高。综上,对津川1号和津原E28而言,米水质量比为1:1.50,浸泡1.0 h,使用纯净水煮饭可以获得更好的食味。     

第七届粳稻发展论坛之09'全国优良食味粳稻品评结果报告

2009年8月8日,北方稻作科技协会组织专家对全国20个优良食味粳稻品种进行品评。水稻食味育种专家、品评专家17人及列席品评代表10人进行品评标准的讨论、制定及品评。品评方法参考日本食味品评标准,结合中国食味品评经验制定。品评结果收到比较满意效果,并引发众多思考:我国优良食味粳稻研究已经达到较高的水平;应制定更加完善的评价体系,提升品评高度;充分发挥优良食味粳稻品种的市场价值;进一步发展协会,提升协会价值。     

自制棉酚饵料对小白鼠的抗生育作用

为了探讨棉酚对小白鼠生殖功能的影响,本试验将30只健康小白鼠(雌、雄各半),随机分为3组,每组10只(雌雄各半),对照组饲喂基础饵料,试验1组饲喂添加1.0%的棉酚的基础饵料,试验2组饲喂添加0.5%溴敌隆的基础饵料,试验结束后计算适口性,睾丸、卵巢脏器系数,制作睾丸、卵巢组织学切片,统计合笼后的产仔情况。结果表明,在适口性方面,添加1.0%棉酚的混合饵料比添加0.5%溴敌隆的混合饵料要好;试验1组,小鼠的生精小管的管壁厚度比对照组薄(P0.01),管腔直径大。试验2组小鼠的生精小管管壁管,管腔直径与对照组相比显著变小(P0.05)。配对以后试验1组小鼠的幼仔个数少于对照组。结果表明,棉酚对小鼠精巢有影响,影响生精小管管壁直径,精子数量,并且降低了雌鼠所怀幼仔个数。说明棉酚能起到降低了雄性小鼠的生育能力的作用。     

不同类型玉米杂交种产量潜力及配套栽培措施的研究

采用L_9(3~4)正交设计,研究了中长穗、耐密植型和平展叶、大穗型两类玉米杂交种的产量潜力和配套栽培措施。结果表明:中长穗、耐密植型杂交种(掖单6号、掖单13号等)具有较高的产量潜力。表现在适于密植(4500—6000/亩)且个体生产能力强,对肥料反应敏感。而平展叶、大穗型杂交种不仅不耐密植(2800—3800/亩)而且对肥料反应迟钝,增产潜力不大。本研究提出了两类杂交种的最优处理组合以及不同杂交种的优化配套栽培措施,并对我省玉米杂交种的选用,不同杂交种的适宜密度以及配方施肥等问题进行了讨论。     

褐家鼠对诱鼠剂1号和不同基饵的喜食性

为控制褐家鼠对配制毒饵所用的基饵及工具捕捉用诱饵进行了筛选,在实验室内用经诱鼠剂1号处理的大米、未处理的大米、鸡饲料、玉米和经诱鼠剂1号处理的大米、碎玉米、大碴子、未经处理的玉米分2组进行有选择性摄食试验。结果表明:第一组试验经诱鼠剂1号处理的大米摄食率最高达69%以上,其次为玉米和鸡饲料分别为9%和6.9%,大米最少,还未达到1%,表明诱鼠剂1号明显提高了褐家鼠对大米的适口性。第二组试验经诱鼠剂1号处理的大米和碎玉米最高分别达到45%和42%,其次是未处理的玉米为10%,经诱鼠剂1号处理的大碴子最少为0.18%,经诱鼠剂1号处理的大米比碎玉米略高,但未达到显著差异,二者作基饵效果都是较好的,但从成本角度考虑碎玉米可以替代大米作为配制毒饵的基料。     

两种不育剂药饵对黄毛鼠的适口性比较

鼠药的适口性是决定鼠害控制效果的关键因素之一。采用单只饲喂法,以稻谷为基饵,分别测定了0.005%炔雌醚和米非司酮药饵对黄毛鼠的适口性。结果表明,黄毛鼠对炔雌醚药饵平均摄食系数显著低于米非司酮;雌雄鼠对炔雌醚和米非司酮药饵的摄食差异显著。炔雌醚显著降低了雌雄鼠对药饵的摄食量,且雄鼠摄食量少于雌鼠。米非司酮提高药饵对雌鼠的适口性,但不影响对雄鼠的适口性;黄毛鼠在处理时间内对药饵的摄食量存在显著变化,雌雄鼠第1 d对炔雌醚药饵和基饵摄食量无显著差异,第2、3 d对炔雌醚药饵摄食量显著少于基饵;雌鼠第1 d对米非司酮药饵和基饵摄食无显著差异,第2、3 d取食药饵显著多于基饵,雄鼠在用药第1 d即表现出对米非司酮药饵的偏好,但随后2 d对基饵和药饵摄食量差异不显著。0.005%米非司酮的稻谷对黄毛鼠具有很好的适口性,而炔雌醚药饵配制有待改善,如增加香味剂、甜味剂等提高其适口性。     

Early insulin and glucagon response associated with food intake in a teleost, the striped bass (Morone saxatilis)

To determine the existence of preabsorptive reflex responses in fish, plasma glucose, insulin and glucagon were measured in striped bass (Morone saxatilis) pre-feeding (baseline: 0 min) and at five times post-feeding (5, 10, 20 and 40 min) following a 15 h fast. Two diets were fed, a basal agar-gel diet, and the agar-gel diet supplemented with a previously identified feeding stimulant mixture comprised of L-alanine, L-serine, betaine and inosine-5-monophosphate at equimolar concentrations (0.1 mol l). After 11 days, blood samples were obtained from the caudal vein. In fish fed the stimulant diet, plasma insulin increased at 5 and 10 min post-feeding but fish fed the basal diet had lower levels than baseline after 5, 10 and 20 min. Glucagon levels were increased in fish fed the stimulant diet at 0–10 min post-feeding, then decreased to levels similar to fish fed the basal diet. Glucose levels were elevated in both treatments post-feeding and were similar in both treatments. These results indicate that there is an early phase of reflex insulin and glucagon secretion in fish, shortly after the beginning of a meal, as has been described in mammals and birds. Furthermore, feed palatability may play an important role in insulin and glucagon secretion.