在集约化养鱼中,常常实行多次收获制,因此,需要终年提供鱼苗。许多鱼类的养殖都是依靠采捕天然鱼苗。蓄养中的亲鱼很少能够自然繁殖,因此很多养殖场用激素进行人工催产。在自然界中,鱼类的产卵受到气候条件的刺激,如光照、水温、水位的突然上升、水化学的变化。养殖人员通过激素刺激产卵的生理过程以代替气候条件刺激所导致的自然产卵。通常采用垂体促性腺激素(GTH)进行催产。有各种 GTH 含量的丙酮干燥垂体可用于这一目的。在家畜中(如牛、猪),常常用激素刺激,使其成熟并同时排卵。为达此目的,使 In intensive fish farming, multiple harvesting schemes are often practiced, and therefore, there is a need to provide fry throughout the year. Many fish farming relies on harvesting natural fry. Feeding broodstock rarely secrete naturally, so many farms use artificial hormones to artificially produce. In nature, the spawning of fish is stimulated by climatic conditions, such as light, water temperature, a sudden rise in water level, and changes in water chemistry. Farmers spawn through physiological processes to stimulate the physiological processes to replace the climatic conditions to stimulate the resulting natural spawning. Pituitary gonadotropin (GTH) is commonly used for oxytocin. Acetone-dried pituitary with various GTH contents can be used for this purpose. In livestock (such as cattle, pigs), they are often stimulated with hormones to mature and ovulate at the same time. For this purpose, make