منابع مشابه
Synchronization of Estrus in Cattle
Numbers of estrus synchronization programmes are available in cattle based on the use of various hormones like progesterone, prostaglandin F2a and their various combinations with other hormones like estrogen and Gonadotrophin Releasing hormone (GnRH). Selection of appropriate estrus synchronization protocol should be made on the basis of management capabilities and expectations of the farmer. S...
متن کاملA review of synchronization of estrus in postpartum cattle.
Estrus has been synchronized in cattle with progestogens, prostaglandins (prostaglandin F2 alpha and its analogues), progestogen-estrogen combinations and progestogen-prostaglandin combinations. Progestogens administered for 14 to 20 d are effective in synchronizing estrus; however, fertility at the synchronized estrus is subnormal. Duration of progestogen treatment can be reduced by combining ...
متن کاملPhysiology and Endocrinology: Synchronization of Estrus in Cattle
McKenzie’s laboratory (U. MO; 1930s) described the estrous cycle of domestic animals. Brownell (Cornell; 1936) reported AI and bull bred pregnancy rates were similar. Between 1938 (first, EJ Perry, NJ) and 1940, 54 AI organizations in 21 states were formed. Ulberg, Christian and Casida (1951) controlled time of ovulation in cows with progesterone (P) injected daily. Trimberger and Hansel (1955)...
متن کاملSynchronization of estrus in swine
Production calendars for most swine farms are based upon the reproductive cycle of sows and gilts. The key reproductive event that determines when females begin their reproductive cycles is the onset of estrus. Estrus normally occurs spontaneously in gilts and mature females that are not pregnant or lactating. Once estrous cycles have begun, they normally occur every 18 to 21 days. From a produ...
متن کاملESTRUS SYNCHRONIZATION SYSTEMS: GnRH
Development of methods to manipulate the estrous cycle so that all cows are in estrus during a short, predefined period (synchronized estrus) while maintaining normal fertility has been a difficult goal to achieve, but has resulted in the creation of valuable synchronization protocols that are available to producers today. Although implementation of estrus synchronization and AI will improve th...
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ژورنال
عنوان ژورنال: Kansas Agricultural Experiment Station Research Reports
سال: 1982
ISSN: 2378-5977
DOI: 10.4148/2378-5977.2558