ADSC 2010 Lecture 23 Outline of Last Lecture I Two Breed Rota Terminal Cross A Advantages B Disadvantages II Endocrine System A Hormones B Specific Endocrine Glands 1 Pituitary 2 Hypothalamus 3 Gonads 4 Thyroid 5 Adrenal Cortex 6 Pancreas 7 Uterus 8 Placenta III Pituitary A Anterior Hormones 1 Growth Hormone 2 Thyroid Stimulating Hormone 3 Adrenocorticotrophic Hormone 4 Follicle Stimulating Hormone a Male b Female 5 Luteinizing Hormone a Male b Female 6 Prolactin a Female B Posterior Hormones 1 Oxytocin IV Hypothalamus A Gonadotropin Releasing Hormone B PIF and PRF V C GHRH and GHIH D Corticotrophin RH Gonads A Gonadal Hormones 1 Testosterone Outline of Current Lecture I Gonads Continued A Estrogen B Progesterone C Relaxin II Uterus A Prostaglandin III Thyroid Gland A Triodothyronine and Thyroxin IV Adrenal Gland A Glucocorticoids B Mineralocorticoids C Adrenaline Noradrenaline V Pancreas A Insulin and Glucagon VI The Estrous Cycle in Cattle VII Chart REPRODUCTION MALE ANATOMY VIII Testes A Sperm production B Androgen production IX Scrotum Current Lecture I Gonads Continued A Estrogen E2 produced in follicles on the ovary and placenta Stimulates estrus behavior standing heat receptive to mating Maintenance of female secondary sex characteristics Needed for normal growth of uterus and female reproduction tract Stimulates duct development in the mammary gland Interacts with oxytocin and prostaglandin to increase uterine contractibility Increases nitrogen retention anabolic effect II III IV V VI B Progesterone P4 produced by the corpus Luteum and placenta Maintenance of pregnancy Promotes uterine contractions Acts synergistically with estrogen to stimulate estrus behavior Promotes alveolar growth in the mammary gland Inhibits LH ovulation C Relaxin produced by ovary Relaxation and dilation of cervix during parturition Relaxation of the pubic symphasis during parturition Uterus A Prostaglandin PGF2 causes regression of corpus Luteum and restarts estrous cycle Thyroid Gland A Triodothyronine T3 and Thyroxin T4 needs iodine for normal function Accelerates all aspects of carb lipids and protein metabolism Increase basal metabolic rate and body temperature Adrenal Gland A Glucocorticoids stimulate gluconeogenesis protein CHO B Mineralocorticoids regulate Na Ca and H2O balance C Adrenaline epinephrine Noradrenaline norepinephrine regulate fight or flight mechanism Stress energy Pancreas A Insulin and Glucagon Regulate the passage of glucose in out of the bloodstream Diabetes lack of insulin The Estrous Cycle in Cattle VII VIII IX Ovulation occurs during estrus Progesterone blocks estrus cycles in future if pregnant Dominant follicle grows mid way through estrus cycle because of FSH peak Chart Puberty mo Estrous cycle length d Duration of Estrus Time of ovulation Cow 6 18 21 18 hr 18 48 hr Ewe 6 12 17 30 hr 24 27 hr Mare 20 22 7 days 24 48 hrs Sow 5 10 21 60 hr 38 42 hr prior to end of estrus Cow ovulates after estrus everyone else during estrus REPRODUCTION MALE ANATOMY Testes two main functions A Sperm production occurs in seminiferous sertoli cells tubules FSH and T 2 regulate B Androgen T2 production occurs in leydig cells LH regulates Scrotum houses and protects testes and regulate temperature Maintains testicle temperature 3 7 F in bull and 9 13 F lower in ram 99 95 for sperm production Tunicadartos thin muscle of scrotum and Cremaster spermatic cord muscle regulates testes distance
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