postpartum anestrous is one of the most important problems in the dairy industry in the world and especially in iran. the objective of present study was to compare the efficacy of two hormonal programs for recycling of postpartum anestrous cows. for this reason, 230 holstein cows from 4 similar dairy herds (with totally 2560 cow and unique management and feeding system) located on the suburb of...

BACKGROUND AND AIM Suboestrus constitutes the largest factor responsible for poor reproductive efficiency in buffaloes. Therefore, oestrus synchronization (OS) and fixed-time artificial insemination (AI) is considered an alternative approach to enhance reproductive efficiency in buffaloes. Thus, the present study was carried out to study the efficacy of modified Ovsynch protocol with fixed time...

Three experiments were conducted to evaluate factors affecting number of surface ovarian follicles and oocytes yield and quality in buffalo. In Experiment 1, ovaries (n = 126) were collected in pairs from slaughtered anoestrus, early pregnant and cyclic buffaloes. Ovarian follicles (1-3, 4-9 and > or = 10 mm diameter) were counted, aspirated and oocytes were recovered and evaluated. In Experime...

The male effect refers to the effect of the introduction of the male on the oestrus cycle of the seasonally anoestrus female. This effect is a neuro-hormonal response that is utilised by flock managers to improve the ovulation rate in females and shorten the breeding season. The introduction of males to the female flock will elicit this response but the use of vasectomised males is a common pra...

About 30% of the total number of gilts selected for reproduction at the large breeding farm units in Vojvodina (Republic of Serbia) are culled due to prolonged pre-insemination anoestrus (estrus not detected until 8 mo of age). The aim of this study was to provide the answer to the following question: do the culling gilts reach cyclic ovarian activity at all? One hundred seventy five culled gil...

The seasonality of reproductive activity in the ewe in temperate latitudes is controlled by photoperiod. Its annual variations control the temporal organization of the sexual cycle by changing the activity of the gonadotrophic axis. Cyclic oestrous behaviour usually appears in the ewe at the end of summer or the beginning of autumn and finishes in winter or at the very beginning of spring. Seas...

Six priming doses of 40 mg progesterone at two day intervals followed by 1,000 I.U. P.M.S. were superior to two priming doses plus P.M.S. in inducing oestrus. At the first insemination after induction of oestrus, fertility was normal in animals which received two doses, but depressed in those which received six doses of progesterone. An injection of 40 mg of progesterone after the injection of ...

One experiment was conducted to determine whether the treatment with artificial long days and exogenous melatonin can induce reproductive activity during spring (seasonal anoestrus) in Mediterranean goats that are in daily contact with bucks and whether this treatment causes a variation in the reactivation of the reproductive activity in the normal breeding season. The experiment started on 4 N...