Refractoriness of Cows Repeatedly Superovulated with Gonadotrophins

Effect of age and norgestomet on endocrine parameters and production of embryos in superovulated beef cows.

Effects of age of cow and a norgestomet (N) implant on number of embryos and endocrine responses to induction of superovulation were studied in old (greater than 12 yr) and young (5 to 7 yr) lactating beef cows. Seventeen cows (8 old and 9 young) received a 6-mg N ear implant on d 4 or 5 of the cycle (d 0 = estrus); the remaining 17 cows (9 old and 8 young) served as untreated controls (C). All...

The effect of time of artificial insemination on fertilization status and embryo quality in superovulated cows.

Thirty nonlactating Holstein cows were superovulated to determine the effect of artificial insemination time on fertilization status and embryo quality. During the luteal phase of the estrous cycle, cows were administered 38 mg FSH-P in a 4-d descending dose regimen. Luteolysis was induced with two injections of prostaglandin on the last day of FSH-P treatment. All cows were continuously monito...

Circulating levels of gonadotrophins in immature mice treated neonatally with antisera to gonadotrophins.

Nonequilibrium Dynamics of Stochastic Point Processes with Refractoriness Nonequilibrium Dynamics of Stochastic Point Processes with Refractoriness

Stochastic point processes with refractoriness appear frequently in the quantitative analysis of physical and biological systems, such as the generation of action potentials by nerve cells, the release and reuptake of vesicles at a synapse, and the counting of particles by detector devices. Here we present an extension of renewal theory to describe ensembles of point processes with time varying...

Relationship between serum total cholesterol level and the number of transferable embryos in relation to milk yield in superovulated cows.