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Advanced Reproduction Physiology (Part 6). Prepared by: A. Riasi http://riasi.iut.ac.ir. Isfahan University of Technology College of Agriculture, Department of Animal Science. Reference: Pathways to Pregnancy and Parturition (Second revised edition) By: P. L. Senger, 2005. Puerperium period.
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Advanced Reproduction Physiology(Part 6) Prepared by: A. Riasi http://riasi.iut.ac.ir Isfahan University of Technology College of Agriculture, Department of Animal Science
Reference: Pathways to Pregnancy and Parturition (Second revised edition) By: P. L. Senger, 2005 Puerperium period
Puerperium • Puerperium period: • Immediately after parurition until the ovarian activity restored. • The time required for complete uterine involution and ovarian activity to resume varies among species.
Puerperium • The four major events of the puerperium are: • Myometrial contraction and expulsion of luchia • Endometrial repair • Resumption of ovarian function • Elimination of bacterial contamination of the reproductive tract
Puerperium • The purpose for myometrial contraction are: • Facilitate discharge of fluid and tissue debris • Compress the uterine vasculature and help minimize the possibility of hemorhage • Reduce the overall size of the uterus
Puerperium • Some condition may cause uterine infection: • Retained fetal membranes • Dystocia • Delay in lochial expulsion
Puerperium • Regardless of the cause, failure to eliminate bacterial contamination will: • Prolong uterine involution • Prolong the puerperium • Delay subsequent pregnancies
Physiological changes in postpartum • There are two phases in postpartum reproduction recovery: • Resumption of FSH and LH pulsatility and reestablishment of LH surge mechanism • Uterine involution
Physiological changes in postpartum • Follicular development begins shortly after calving with a transient increase inFSH. • The first postpartum dominant follicle undergoes one of three fates: • Ovulation • Atresia and turnover • Cyst formation
Physiological changes in postpartum • Some endocrine hormones can influence GnRH secretion. • The actions may be on: • GnRH neurons • The neuronal pathways that impinge upon GnRH neurons • The pituitary gonadotroph
Physiological changes in postpartum • The hormonal control arises from tissues that respond to the metabolic or nutritional status: • Pancreas with secretion insulin • Liver with secretion IGF-I • Adipose tissue with secretion leptin
Physiological changes in postpartum • The metabolites and hormones that influence on GnRH may act directly on sensitivity of the ovary to LH and FSH. • Insulin and IGF-1 may affect the ovaries independent of LH and FSH
Physiological changes in postpartum • Lower metabolic hormone concentrations may contribute to a decrease in ovarian LH responsiveness. • Lactating cows had larger preovulatory follicles than heifers but lower preovulatory concentrations of estradiol in blood. Why?
Nutrition and reproduction interaction • The early embryonic loss is affected by: • Nutritional factors • Reproductive management
Nutrition and reproduction interaction (Mapletoft et al. 1986)
Nutrition and reproduction interaction • Energy deficiency should be considered as a problem in herds, in this condition: • Cows lose excessive amounts of body condition during early lactation. • Cows are not cycling normally by 30-40 days after calving.
Nutrition and reproduction interaction • Cows in better energy balance: • Had greater intrafollicular IGF-I • Had plasma progesterone levels • Produce more oocytes graded as good.
Nutrition and reproduction interaction • NEB not only delays resumption of ovulatory cyclesbut it might also influence the quality of occytes once cows are inseminated.
Nutrition and reproduction interaction • When heifers are fed inadequate amounts of energy, they reach sexual maturity later. • If energy deficient rations are fed to heifers that have begun to have normal estrous cycles, they may stop cycling.
Nutrition and reproduction interaction • The first key is to understand the nutrient needs of cattle at different phases of production and reproduction. • The second key is to know the nutrition content of the predominate feedstuff and supplement as needed.
Nutrition and reproduction interaction • The primary nutrients that should be considered in providing for good reproduction are: • Energy (NEB) • Protein (RDP/RUP) • Minerals (Ca, Se, Cu, Cr) • Vitamins (A, E) • Fiber (chewing and rumination)
Nutrition and reproduction interaction • Energy intake may be the most important nutritional factor affecting reproduction. • Excessive energy intake during late lactation and the dry period can cause “fat cow” problems
Nutrition and reproduction interaction • In cows with NEB: • Blood concentration of NEFA increase • Blood concentration of BHBA increase • At the same time IGF-I, glucose and insulin are low.
Nutrition and reproduction interaction • It has shown cyclic cattle that are underfed have progressively smaller and less estrogenic dominant follicles (Bossis et al., 1999). • The reduction in fertility associated with NEB is, at least in part, mediated by the damaging effects on immunity and postpartum health.
Nutrition and reproduction interaction • In addition to the changes in energy balance, circulating concentrations of antioxidants also decrease around parturition.
Nutrition and reproduction interaction Poor nutrition Lower metabolic hormones: • Somatotropin • Insulin • IGF-I Low energy intake Smaller and less estrogenic dominant follicle Lower sroidogenic capacity of corpora lutea Smaller corpora lutea Lower progesterone concentration in blood Lower reproduction performance
Nutrition and reproduction interaction • Expression of hepatic growth hormone receptor (GHR-1A) is thought to be responsible for the concentrations of IGF-I in plasma of cows.
Nutrition and reproduction interaction • IGF-I is an important hormonal signal that influences reproductive events: • Stimulation of cell mitogenesis • Hormonal production • Embryo development
Nutrition and reproduction interaction • Feeding diets that promote greaterinsulin concentrations are benefit for fertility.
Some research papers associated to this lecture Mateus, L. et al., 2002. Influence of puerperal uterine infection on uterine involution and postpartum ovarian activity in dairy cows. Reprod. Dom. Anim. 37: 31-35. Crowe, M. A. 2008. Resumption of ovarian cyclicity in post-partum beef and dairy cows. Reprod. Dom. Anim. 43: 20–28. McNamara, S. et al., 2008. Effect of milking frequency in early lactation on energy metabolism, milk production and reproductive performance of dairy cows. Livestock Science 117: 70–78. Bisinotto, R. S. et al. 2012. Influences of nutrition and metabolism on fertility of dairy cows. Anim. Reprod. 9: 260-272.