Glossary

ADG: Average Daily Gain: zootechnical criteria for assessing the growth of animals in grams per day.
Abortion: Premature termination of gestation.
Adenohypophysis: Anterior part of the pituitary gland which regulates several physiological processes achieved through the secretion of various hormones.
Anoestrus: State characterised by the absence of cyclicity and therefore the absence of heat. It is frequently observed after parturition for a longer or shorter period depending on the breed and physiological status.
Atresia: Particular form of aplasia: refers to an ovarian follicle that has not completed its final phase of growth and maturation, thus evolving to regression.
Calving: Giving birth to a calf.
Cervix: Narrowed portion of hollow organs such as the uterus.
Corpus luteum: Organelle formed after ovulation of a dominant follicle. Its thick wall is formed from progesterone-secreting cells. It is the sign of the cyclical activity being maintained in the event of pregnancy.
Culling: Process of removing an animal from the breeding stock, on most occasions sending it to be slaughtered.
Cyclicity: Characterizes what is cyclical: returns to regular intervals and is repeated in a cycle. Return to cyclicity is highly important in the post-partum phase.
Deficiency: Absence, lack of an adequate quantity: e.g. deficiency of vitamins.
Dinoprost: Molecule belonging to the family of natural F2alpha prostaglandins. It is the active ingredient of Enzaprost T.
Dioestrus: Phase of the oestrous cycle which corresponds to the luteal phase during which the corpus luteum is present. From day 5 to 18-20.
Dominance: Phase of the follicular wave in which the largest follicle takes over the rest and becomes the dominant follicle maturing completely.
Dystocia: Essentially mechanical difficulty which may occur during parturition.
Echographic image: Technique used to visualize internal organs or a foetus through the use of ultrasounds.
Endometritis: Inflammation of the endometrium (inner uterine lining) caused by infection.
Epiphysis: Also called pineal gland, is sensitive to certain environmental factors such as photoperiod, and is responsible for the secretion of melatonin.
Estrogen: Hormone secreted by the ovary which plays a role in ovulation when its level in blood increases.
FSH: Follicle Stimulating Hormone: responsible for the growth of ovarian follicles.
Fertilisation: Union of a male gamete (sperm) with a female gamete (ovum) to give an egg, or zygote.
Fertility: Ability to procreate. From a zootechnical point of view: capacity of being fertilized.
Fertility: Ability of a living organism to reproduce. From a zootechnical point of view: ability to give birth to a calf, a lamb, a goat or a piglet.
Follicle: Small secretory or excretory cavity. Ovarian follicles grow until ovulation or female gamete emission.
GPG: Acronym for GnRH-prostaglandin-GnRH. Synchronization protocol based on injections of GnRH and prostaglandins on certain days.
Gamete: Male or female reproductive cell which contains only one chromosome of each pair in its nucleus and joins the gamete of the opposite sex (fertilization) to give an egg (zygote).
Gestation: State between implantation and parturition of female viviparous pregnant species.
Glycemia: Levels of glucose in blood.
GnRH: Gonadotropin Releasing Hormone is secreted by the hypothalamus causing the release of FSH and LH.
Gonadoreline: Also known as GnRH. Active ingredient of Cystoreline.
Granulosa: Inner membrane of the ovarian follicle. 10% of it is formed by large cells called luteal cells.
Heat: Also “oestrus”. Physiological and behavioural phenomena that precedes and accompanies ovulation in female mammals.
Hypothalamus: The part of the brain that lies below the thalamus, forming the major portion of the ventral region of the diencephalon and controls autonomic nervous activities and part of the hormonal system.
Inhibin: Hormone secreted by the follicles (or Sertoli cells in the male) that selectively inhibits FSH secretion.
Involution: Spontaneous or induced decrease of a tissue, organ or tumor. Particular method of evolution of an organ in which its inicial appearance is restored e.g. involution of the uterus after parturition.
Ketosis: State characterized by the presence of ketone bodies (including acetone) in the blood.
LH: Luteinising hormone: responsible for the final maturation of the follicle and ovulation.
Lochia: Vaginal discharge containing especially blood which lasts a few weeks after parturition as a result of uterine involution.
Luteinisation: All the changes undergone by an organ under the influence of progesterone, especially by the follicle after ovulation which becomes the corpus luteum, by the endometrium, which evolves to ensure the implantation of the fertilized egg, or by follicular cysts which become luteal.
Luteolysis: Rapid degeneration of the corpus luteum in the late luteal phase under the action of prostaglandins F2alpha secreted by the uterus when fertilization does not occur.
Meiosis: Double cell division that results in halving the number of chromosomes, which occurs during the formation of reproductive cells, or gametes.
Melatonin: Hormone secreted by the pineal gland directly under the influence of the photoperiod, it is secreted only at night.
Metoestrus: Phase of the oestrus cycle, which occurs in the period after ovulation. It lasts from day 1 to day 4.
Metritis: Inflammation of various tissues of the uterus, mainly of the uterine lining (endometritis), but also of the uterine muscle (myometritis or cervicitis).
Myometrium: Layer of smooth muscle cells that form the wall of the uterus.
Oestradiol: Steroid hormone (derived from sterols, polycyclic alcohols complex) mainly secreted by the female ovary. Its increase is involved with ovulation.
Oestrus: Also known as heat, is the physiological and behavioral phenomena which precedes and accompanies ovulation in female mammals.
Oocyte: Ovarian cell, the precursor of the ovum.
Oogenesis: Female form of gemetogenesis. Creation of the ovum.
Ovary: Female reproductive glands, located symmetrical on either side of the uterus, which produce the female gametes.
Ovulation: Expulsion of an ovum from the ovary in female animals.
Oxytocin: Polypeptide hormone (consisting of a chain of amino acids) synthesized by the hypothalamus and secreted and stored by the posterior pituitary gland. Its function is to stimulate uterine muscle contraction and promote breastfeeding.
PGF2alpha: Prostaglandin secreted by the uterus under the influence of oxytocin, that causes luteolysis.
PMSG: Pregnant mare’s serum gonadotrophin: also called eCG. Gonadotropin extracted from pregnant mare’s serum which causes the final maturation of the dominant follicle and ovulation.
PRID: Progesterone Releasing Intra-vaginal device: intra-vaginal device impregnated with progesterone.
Pituitary: Gland located at the base of the brain just below the hypothalamus. It is divided into an anterior lobe and a posterior lobe. The anterior lobe or adenohypophysis secretes FSH and LH, prolactin, growth hormone (GH), TSH and ACTH. The posterior lobe secretes oxytocin and vasopressin.
Post-partum: Period between parturition and the return to cyclicity (and therefore appearance of heat).
Pro-oestrus: Period of the oestrous cycle that precedes oestrus. It lasts 18 to 22 days.
Progesterone: Steroid hormone secreted by the corpus luteum of the ovary which has the property of making the endometrium suitable for implantation, maintenance and development of the fertilized egg. (Progesterone also results in multiple activities for the endometrium, myometrium, cervix, vagina and udder.). It inhibits GnRH secretion by feedback action on the pituitary.
Prostaglandin: Substance derived from a fatty acid, present in many body tissues and involved in numerous biological processes (contraction of the uterus, inflammation, blood clotting, etc.).
Puberty: Transition between youth and adulthood, characterized by the development of sexual characteristics, accelerated linear growth and acquisition of reproductive functions.
Puerperium: Period following parturition
Pulse: Characterises the rate of pulsatile secretion of certain hormones such as GnRH and LH.
Pyometra: Infection of the uterus lining (metritis) characterised by the accumulation of pus in its lumen.
Recruitment: Phase of follicular wave during which a cohort of twenty follicles resumes its growth under the influence of FSH.
Repeat breeding: Syndrome in which there is a return to regular heat despite inseminations and non-successive fertilizing, characterised by the absence of clinically detectable disease or disorder.
Seasonality: Refers to species that breed in specific seasons depending on the photoperiod such as sheep and goats.
Selection: Stage of the Follicular wave in which 3 or 4 previously recruited follicles move from an FSH-dependent phase to an LH-dependent phase.
Spermatozoon: Fertilising male cell or male gamete, small and capable of active swimming. The distinctive element of the sperm.
Suboestrus: State in which there is a silent oestrus behaviour. The animal’s cyclic activity is normal, but no heat is observed.
Suckler cow: Nursing cow used for feeding suckling calves.
Synchronisation: Two or more events that occur at the same time or in a precise coordinate succession: oestrus synchronization allows an organised and grouped artificial insemination.
Theca: Outer membrane of the ovarian follicle, divided into two layers: an external fibrous layer (tunica externa) and an internal cellular vascular layer (tunica interna).
Uremia: The presence of excessive amounts of urea and other urinary waste products in the blood. Also called azotemia.
Uterus: Genital organ of female mammals, located between the fallopian tubes and the vagina, which hosts the fertilized egg until its full development takes place and it is expelled at the end of gestation.
Vagina: Internal genitalia of female placental mammals which attaches on one end to the cervix of the uterus and opens at the other end forming the vulva.
Vulva: External genitalia in female placental mammals.
ECG: Equine chorionic gonadotropin, formerly known as PMSG (pregnant mare serum gonadotrophins). Gonadotropin extracted from pregnant mare serum. Causes the final maturation of the dominant follicle and ovulation.
Oviduct: Duct through which female gametes are expelled from the ovary in animals.