Studies on the in vitro fertilization in cattle

The in vitro maturation,fertilization and development of bovine ovary oocytes in two different cultural systems A and B were studied under the conditions of 38.5℃,5%CO2,95%air and 100% humidity.The maturation rates were 94.5% and 91.3%,respectively,and the difference was extremely significant.Frozen semen were thawed and sperm wrer capacitated with three kinds of capacitation agents for fertilization.The pronucleus rates were 76%,65%-68%and 62%respectively.The rates of embryos developed to morula and blastocyst were 19%,16%and 17% espectively.The developmental rates of embryos cocultured with bovine oviductal epithelium cells and bovine granulosa cells were 25%and 23.4% respectively,with no significant difference.Fresh embryos were transplanted into 15 recipiens,and three of them were pregnant and calves were born in 1990 and 1991,The pregnant rate was 20%,The emryos developod faster before 8-cell stage and slower after 8-cell stage ,in vitro than in vivo.     

Studies on the in vitro fertilizaion in cattle

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Hot cognition in agricultural policy preferences in Norway?

The paper tests the hypothesis that cultural and social background is far more influential to form preferences about policy than the level of fact-based knowledge a person possesses. The data for the case study stem from a web-based survey among a representative sample of the adult population in Norway. The degree of knowledge of agriculture in this paper is operationalized through questions on five key characteristics of Norwegian agriculture that frequently arise in the public discussion. The results show that the amount of fact-based knowledge of agriculture to a very little extent explains differences within the sample. The cultural background of respondents is much more suited to explain agricultural policy preferences. Knowledge, however, shifts the attention from food price issues towards the delivery of public goods. The results allow us to hint at hot cognition as a possible explanation for such findings.     

Role of gelatinous layer in growth stress generation in tension wood

Role of gelatinous layer in growth stress generation in tension wood@Bruno Clair$Laboratoire de Mécanique et Génie Civil,Université Montpellier 2,France @Joseph Gril$Laboratoire de Mécanique et Génie Civil,Université Montpellier 2,France     

Agricultural Sciences in China

Instruction to Authors Aims and Scope Agricultural Sciences in China （ASC） is an official publication of the Chinese Academy of Agricultural Sciences （CAAS）. Agricultural Sciences in China seeks review and original contributions from all areas of agriculture and animal husbandry under the headings of： Crop Genetics ＆ Breeding, Germplasm Resources, Molecular Genetics, Tillage ＆ Cultivation, Physiology ＆ Biochemistry, Ecology ＆ Environment, Soil ＆ Fertilization, Irrigation, Plant Protection, Horticulture, Storage, Fresh-keeping, Processing, Animal Science, Veterinary Science, Resource Insect, Review, Monograph and Short Communication.     

Agricultural Sciences in China

Instructions to Authors Agricultural Sciences in China （ASC） is an official publication of the Chinese Academy of Agricultural Sciences （CAAS）. ASC seeks review and orgiinal contributions from all areas of agriculture and animal husbandry under the headings of： Crop Genetics ＆ Breeding, Germplasm Resources, Molecular Genetics, Tillage ＆ Cultivation, Physiology ＆ Biochemistry, Ecology ＆ Environment, Soil ＆ Fertilization, Irrigation, Plant Protection, Horticulture, Storage, Fresh-keeping, Processing, Animal Science, Veterinary Science, Resource Insect, Review, Monograph and Research Notes.     

Phosphorus Deficiency in Ducklings

20 one-day-old Tianfu ducklings were fed on a natural diet deficient in phosphorus (Ca 0.80%, P 0.366%) for three weeks and examined for signs and lesions. Signs began to appear at the age of one week, and became serious at two weeks. 13 ducklings died during the experiment. Morbidity was 100% and mortality was 65%. The affected ducklings mainly showed leg weakness, severe lameness, depression, lack of appetite and stunted growth. The serum alkaline phosphatasc activities increased markedly. The scrum phosphorus concentration, tibial ash, ash calcium and phosphorus content decreased obviously. At necropsy, maxillae and ribs were soft, and the latter was crooked. Long bones were soft and broke easily. The hypcrtrophic zone of the growth- plate in the epiphysis of long bones was lengthened and ostcoid tissue increased in the mctaphyseal spongiosa histopathologically. The above mentioned symptoms and lesions could be prevented by adding phosphorus to the natural deficient diet (up to 0.65%). The relationship be