饲料中不同蛋白和钙对鸡肾脏影响的研究

通过饲喂不同蛋白,人工试验出鸡尿酸盐沉积模型,并观察鸡肾脏临床病理变化。采用高蛋白高钙饲料造模,将动物分健康对照组、高蛋白组、高钙组、高蛋白高钙组,通过鸡的死亡率、采食饮水量的变化、体重变化率、血液中尿酸盐含量等指标,考察肾肿模型,其中用磷钨酸显色法测定鸡血液中尿酸的含量。高蛋白高钙能使鸡增重率降低,鸡的饮水量、采食量降低,死亡率升高,血清中尿酸盐含量升高,尿酸盐在肾脏沉积形成花斑肾。用44%高蛋白高钙(0.5%钙)可以人工试验出鸡尿酸盐沉积模型。     

沙棘优良品种选择试验初报

通过对不同引种区域的沙棘优良品种的栽培对比试验,选育出适合阜新地区栽培的优良沙棘品种。根据3a的调查结果,按照幼林的生长量、结实量和百粒果重等指标的综合分析,获得"丘杂F1代"、"白丘杂交"、"森淼"、"亚中杂交"等4个品种优于"辽阜1号"、"辽阜2号"对照品种,也优于引种的其它品种。     

高蛋白专用稻特优K91高产栽培技术研究

通过对高蛋白专用稻特优K91秧龄、种植密度、施肥水平(以N为代表)3个栽培因子的研究,明确了特优K91在三明市低海拔地区作连晚栽培的较佳技术组合是:肥力中等田段30 d,30万丛/hm2,195 kg/hm2;肥力中上田段30～35 d,21～25.5万丛/hm2,135～195 kg/hm2.     

Heterosis in crisphead lettuce (Lactuca sativa L.) hybrids

Summary Six of 16 F₁ hybrids from diverse crosses of crisphead lettuce with butterhead, cos or other crispheads significantly outyielded their respective better parent. Four were crosses between crisphead and cos parents, one was a butterhead × crisphead cross and one, a winter crisphead × winter crisphead cross. This latter hybrid plus one other also proved heterotic in a subsequent trial of ten crosses involving five winter crisphead parents, with yield excesses over better parent of 16 and 19%. It appeared significant that the heterotic crosses were given by parents of dissimilar origin. Trials of F₂ segregants from one of these heterotic hybrids enabled predictions to be made for 10.2 to 24.1% yield increases over better parent by the retention and clonal multiplication of the 10% highest yielding selections. Heterosis demonstrated in these trials may constitute the first reported cases in lettuce.     

Pesticides

Abstract

The anticoagulant chlorophacinone was evaluated in the laboratory for the control of the gerbils Tatera indica Hardwicke and Meriones hurrianae (Jerdon), which are major pests of agricultural crops, grassland and reforestation projects in the arid zone of India. Millet and sorghum grain treated with chlorophacinone was offered in no‐choice feeding tests. The results showed that 100% mortality occurred after seven and five days with 0.0075% chlorophacinone and after three and four days with 0.01% chlorophacinone in T. indica and M. hurrianae respectively. The anticoagulant‐treated bait was significantly less palatable than untreated bait, except bait containing 0.0075% chlorophacinone to T. indica. It is concluded that 0.0075% chlorophacinone can be effectively used to control the gerbils, especially bait‐shy populations previously exposed to zinc phosphide bait. Chlorophacinone appears to give more effective control than warfarin and fumarin, and slightly less effective control than brodifacoum.