大棚西瓜放蜂栽培配套技术

西瓜是平湖市的传统优势产业，随着经济的发展和人民生活水平的不断提高，西瓜消费逐渐向高档化、礼品化发展。近年来，平湖市的小型西瓜发展较快，年栽培面积在700hm^2以上，种植方式以大棚设施栽培为主。由于大棚相对密闭的环境，昆虫等授粉媒介活动少，影响西瓜正常结果，生产上常采用人工授粉或喷(涂)激素提高坐果率，费工又费力，且     

无公害饲养肉牛的技术探讨

×西本 )、西夏本 (西门塔尔×夏本 )等。4 .2　品种的来源　按照ＧＢ/Ｔ184 0 7.3的标准从无特定病源区内或无公害标准牛场内引进 ,引进时要按照ＧＢ16 5 4 9《畜禽产地检疫规范》进行产地检疫。引进后要在观察舍观察 15～ 2 0天 ,确定为健康合格后方可进入饲养舍进行饲养。5　饲养标准与饲养5 .1　饲养标准饲养标准是无公害饲养肉牛的基本条件。根据情况选择一个好的饲养标准 ,对提高肉牛品质与经济效益十分有利。 1992年 ,我国颁布了ＳＢ/Ｔ10 0 79《肉牛精料补充料》行业标准 ;1993年 ,又制定了《中国肉牛饲养标准》(报批稿 ) ,为肉牛饲…     

鸡传染性法氏囊病的诊断与综合防治

本病不受季节限制和影响，四季均可发生，以3—8月份流行较为严重，尤其春夏、夏秋季节交替时更为严重。     

Breed differences and intra-breed genetic variability of dermatoglyphic pattern of cattle

SUMMARY: Muzzle dermatoglyphics - n. ridges, granula and vibrissae - were analysed in various breeds. Differences among these in most traits were significant. Herd effects accounted for about 1/10 of the variance and heritability, estimated by combining sib, halfsib and dam-daughter correlations corrected for herd differences was above 50% for ridges and vibrissae and about 30% for granula. Genetic correlations between ridge counts and n. vibrissae in different nose fields, respectively, were high as they were between the former and n. granula but they were negative or very low between vibrissae and the other two traits. Asymmetry among the counts in the two muzzle sides was significant for nearly all traits, Heritabilities were low, around 10 to 20%, and the crossbreds had less asymmetry than their parental breeds. The correlations among asymmetry measures were low. ZUSAMMENFASSUNG: Rassenunterschiede und genetische Variabilit?t von Flotzmaulmustern Flotzmaulmerkmale - Zahl von Leisten, Warzen und Haaren - wurden in verschiedenen Rassen untersucht. Unterschiede zwischen diesen waren für alle Merkmale signifikant. Herdeneinflüsse verursachten etwa 1/10 der Varianz und Heritabilit?tswerte, gesch?tzt aus Korrelationen zwischen Zwillingen, Halbgeschwistern und T?chter-Müttern, korrigien für Herdeneinflüsse, variierten zwischen 36 und mehr als 50%. Genetische Korrelationen zwischen Leistenzahl und Zahl von Haaren in verschiedenen Flotzmaulfeldern waren hoch, ebenso wie die zwischen ersteren und Zahl von Warzen, aber sie waren negativ oder sehr gering zwischen Haaren und den andern beiden Merkmalen. Asymmetrie zwischen Zahlen in beiden Flotzmaulh?lften war signifikant für fast alle Merkmale. Heritabilit?tswerte waren niedrig, etwa 10-20% und Kreuzungstiere zeigten weniger Asymmetrie als ihre Herkunftsrassen. Die Korrelationen zwischen Asymmetriema?en waren niedrig.     

Crop scientists break down barriers at ames meeting

For years, crop science has been balkanized, with specialists in rice, corn, and soybeans, for example, working on their own commodities and attending their own meetings. But at the First International Crop Science Congress, held in July in Ames, Iowa-an 8-day event 3 years in the making-the discipline displayed a newfound hybrid vigor. More than 1000 researchers of various persuasions, including plant molecular biology, classical plant breeding, agronomy, and soil science, representing 85 countries, shared their expertise in basic and applied studies. Here are a couple of proposals for expanding world food production and another that shows the diverse roles crops can play.