Genetic and phenotypic parameter estimates for body weights and egg production in Horro chicken of Ethiopia

A breeding program has been established in 2008 to improve productivity of Horro chicken, an indigenous population in the western highlands of Ethiopia. The pedigree descended from 26 sires and 260 dams. Body weights were measured every 2 weeks from hatch to 8 weeks then every 4 weeks for the next 8 weeks. Egg production was recorded to 44 weeks of age for one generation. Genetic parameters were estimated using animal model fitted with common environmental effects for growth traits and ignoring common environment for egg production traits. Direct heritabilities ranged from low (0.15 ± 0.08), for body weight at 6 weeks, to moderate (0.40 ± 0.23), for hatch weight. Heritabilities of common environmental effects on growth were high at hatch (0.39 ± 0.10) and remained low afterwards. Age at first egg showed a very low heritability (0.06 ± 0.15). Heritabilities of egg numbers in the first, second, third, and fourth months of laying were 0.32 (±0.13), 0.20 (±0.16), 0.56 (±0.15), and 0.25 (±0.14), respectively. Heritabilities of cumulative of monthly records of egg numbers were from 0.24 ± 0.16 (for the first 2 months, EP12) to 0.35 ± 0.16 (over the 6 months, EP16). Body weight at 16 weeks of age (BW16) has a strong genetic correlation with the cumulative of monthly records: 0.92 (with EP12), 0.69 (with EP36), and 0.73 (with EP16). Besides their strong association, BW16 and EP16 showed higher heritability, relative to their respective trait categories. These two traits seemed to have common genes and utilizing them as selection traits would be expected to improve both egg production and growth performance of local chicken. However, the standard errors of estimates in this study were mostly high indicating that the estimates have low precision. Parameter estimations based on more data are needed before applying the current results in breeding programs.     

硝酸银诱导的大豆子叶中大豆Kunitz胰蛋白酶抑制剂的研究

采用二维电泳技术对硝酸银诱导的大豆子叶微粒体膜蛋白进行分离,利用四极杆-飞行时间串联质谱,对仅存在于诱导样品而不存在于对照样品中的蛋白质点进行氨基酸序列测定和分析,以期研究硝酸银处理对大豆子叶微粒体蛋白质的影响。结果显示:硝酸银可以诱导大豆Kunitz胰蛋白酶抑制剂(SKTI)的产生,在诱导处理的子叶中大量存在其成熟形式,也存在其5 kDa小亚基,小亚基含有“GIGTIISSPER”和“FIAEGNPLR”氨基酸序列。该研究结果为SKTI的深入研究提供了实践依据,并为其分离纯化提供了简便途径,从而有利于对其更多性质的进一步研究。     

荷兰高达公司的马铃薯蒸汽去皮系统

在马铃薯加工过程中,蒸汽去皮是关系到降低成本和提高产品质量的关键环节。荷兰高达公司30年来致力于去皮技术的研究。他们把目标定位于降低生产成本,特别是降低水污染的研究,所研制的马铃薯蒸汽去皮系统生产设备及生产线,经过不断的改进和发展,取得了成功。早在20世纪60年代,荷兰最大的马铃薯加工企业(其中多数是法式薯条生产企业),开始了生产线的运营。随着生产线能力的迅速扩大,废水问题成了荷兰社会的焦点。马铃薯加工过程中的水污染主要产生于去皮工序。于是,马铃薯加工设备制造商开始寻找降低水污染的途径。在荷兰和美国,生产商不断地推出具有世界先进水平的去皮机。高达公司最新研制的分离—定子式去皮机、刷加带式清皮机及其去皮生产线已经投放市场。目前,在许多欧洲国家,以及美国、加拿大、澳大利亚、日本、中国等国家的大型马铃薯和蔬菜加工企业都在使用高达公司的机器。