ADSC 2010 Lecture 22 Outline of Last Lecture I Mating Systems 1 Radom Mating 2 Inbreeding 3 Outbreeding a Relationship of heritability and heterosis for different traits b How do we combine selection and mating systems II Crossbreeding Systems 1 Two Breed Terminal Cross 2 Two Breed Rotational Cross 3 Three Breed Rotational Cross Outline of Current 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 IV V 4 Follicle Stimulating Hormone a Male b Female 5 Luteinizing Hormone a Male b Female 6 Prolactin a Female B Posterior Hormones 1 Oxytocin Hypothalamus A Gonadotropin Releasing Hormone B PIF and PRF C GHRH and GHIH D Corticotrophin RH Gonads A Gonadal Hormones 1 Testosterone Current Lecture I Two Breed Rota Terminal Cross 1 3 A 2 3 B 2 3 A 1 3 B Replacement females Herd 1 Bull breed A Herd 2 Bull breed B Older cows Cull cows Replacement females Herd 3 Bull breed C 1 A rd ed He bre ll Bu Steers Cull heifers Steers Cull heifers Market5 100 of progeny II III A Advantages Produce replacement females Heterosis in females Maximum heterosis in terminal cross calves Can utilize complementary in terminal cross calves B Disadvantages Only 67 heterosis in females and rotational calves Requires greater number of animals to implement Requires greater management input Endocrine System endocrine glands secrete hormones carried to other parts of the body target organ tissues through the blood stream A Hormones chemical substances that are carried by the blood stream to a target organ and elicit a consistent response B Specific Endocrine Glands 1 Pituitary anterior posterior base of brain 2 Hypothalamus above pituitary 3 Gonads testes ovaries 4 Thyroid lobes on sides of larynx 5 Adrenal Cortex close to kidneys 6 Pancreas near duodenum 7 Uterus 8 Placenta Pituitary A Anterior Hormones 1 Growth Hormone GH protein RBST bovine somatrotropin stimulates growth of bone and muscle 2 Thyroid Stimulating Hormone TSH glycoprotein stimulates thyroid gland 3 Adrenocorticotrophic Hormone ACTH protein stimulates adrenal cortex to secrete corticosteroids glucorticoids involved in energy metabolism 4 Follicle Stimulating Hormone FSH glycoprotein a Male stimulates sertoli cells in testes to initiate spermatogenesis up to secondary spermatocytes IV V b Female stimulates granulose cells in ovary to enlarge and develop the follicle on ovary acts synergistically with luteinizing hormone to stimulate estrogen production 5 Luteinizing Hormone LH glycoprotein a Male stimulates interstitial cells leydig cells of testes to produce testosterone ICSH b Female stimulates luteal cells on ovary Ovulation Formation of corpus Luteum CL Stimulates progesterone production and secretion Acts with FSH to produce estrogen 6 Prolactin PRL Protein a Female Initiation and maintenance of lactation mammary tissue Induces maternal behavior B Posterior Hormones 1 Oxytocin protein stimulates contraction of smooth muscle of uterus and oviduct and thus Stimulates transport of sperm and ova Expulsion of fetus at parturition Myoepithelial cells in mammary gland to contract and release milk milk letdown Hypothalamus mainly produces releasing and inhibiting hormones A Gonadotropin Releasing Hormone GnRH FSHRH LHRH stimulates release of FSH and LH from anterior pituitary B PIF and PRF prolactin inhibiting releasing hormones C GHRH and GHIH somatostatin stimulates release inhibition of release of growth hormones D Corticotrophin RH stimulates release of ACTH from anterior Pituitary Gonads A Gonadal Hormones steroid derived from cholesterol 1 Testosterone T2 produced in leydig cells of testes interstitial cells Stimulates spermatogenesis in the seminiferous tubules Develops maintains secondary accessory sex glands Develops secondary sex characteristics Increases libido sexual desire Increase nitrogen retention protein synthesis and muscle growth
View Full Document
Unlocking...