in 1909, several years before the famous `organizer’ experiments of spemann and mangold, ethel browne demonstrated induction of a secondary axis in hydra by grafting a hypostome. based on this and subsequent work, in the late sixties, lewis wolpert proposed the theory of morphogen gradients and positional information. we have studied secondary axis induction by hypostome and foot tissue using t...

Ultrasound has relatively low use in the veterinary practice of cattle, especially diagnosis respiratory diseases. There is little information on imaging patterns and occurrence these diseases calves from dystocic parturition, ability to diagnose subclinical The correct clinical aims support efficient growth expression genetic potential for replacer calves. Eighteen Holstein calves, five which ...

The aim of this study was to evaluate the effect of replacing progesterone injections by progesterone vaginal inserts on productive and reproductive parameters of lactating cows with reproductive problems after prolonged periods of heat stress. Fifteen Holstein cows were randomly assigned to one of three treatments: 1) treated with two progesterone vaginal inserts (P4-INS); 2) treated with prog...

Darturition is believed to be initiated when adrenocorticotropic hormone (ACTH) from the fetal pituitary gland causes a release of cortisol from the fetal adrenal cortex (1). The fetal cortisol reduces placental progesterone production and increases placental estrogen production, resulting in release of prostaglandin F2, (PGF) from the uterus (1). Consequently, uterine activity increases, the c...

Coxiella burnetii is an intracellular bacterial pathogen that causes Q fever. Infected pregnant goats are a major source of human infection. However, the tissue dissemination and excretion pathway of the pathogen in goats are still poorly understood. To better understand Q fever pathogenesis, we inoculated groups of pregnant goats via the intranasal route with a recent Dutch outbreak C. burneti...