ADSC 2010 Lecture 26 Outline of Last Lecture I Uterus A Uterine Horns B Uterine Body C Cervix II Vagina A Capacitation III Vulva IV Clitoris V Reproduction Ovarian Cycle A Follicles 1 Primary 2 Secondary 3 Tertiary 4 Gratian B Ovulation C Corpus Luteum D Fertile Life of Ova and Sperm 1 Ova 2 Sperm E Fertilization VI Reproduction Embryonic Development A Blastocyst 1 Inner cell mass a Endoderm b Mesoderm c Ectoderm 2 Trophoblast 3 Blastocyst Cavity VII Reproduction Implantation A Implantation B Implantation Times VIII Reproduction Placenta IX A Placenta 1 Chorion 2 Allantois 3 Amnion B Placental Attachment C Functions of the Placenta 1 Respiration 2 Nutrition 3 Waste Removal 4 Protection 5 Hormone Production Reproduction Pregnancy A Hormonal Changes During Pregnancy Outline of Current Lecture I Reproduction Gestation Length II Reproduction Parturition A Preparatory Stage B Expulsion of Fetus C Expulsion of Placenta III Factors Influencing Fetal Size 1 Genetics 2 Age and Size of Dam 3 Nutrition 4 Litter Size 5 Ambient Temperature 6 Fetal Hormones Current Lecture I Reproduction Gestation Length Cow 275 days or 9 months Ewe Dow 147 Days or 5 months Sow 114 days or 3months 3 weeks and 3 days Mare 336 days or 11 months II Reproduction Parturition A Preparatory Stage Dilation of cervix relaxin Increased uterine contraction oxytocin III Rupture of chorio all antois Cow 2 6 hours Sow 2 4 hours Mare 2 3 hours B Expulsion of Fetus Passage of fetus through cervix into vagina Rupture of fluid sacs Reflex contractions push fetus through birth canal Cow and Ewe 5 1 hours Sow 1 4 hours Mare 10 20 minutes C Expulsion of Placenta Cow and Ewe 4 5 hours Sow 1 4 hours Mare 5 3 hours Factors Influencing Fetal Size 1 Genetics Heritability for birth weight is about 40 2 Age and Size of Dam Older larger dams produce a larger fetus 3 Nutrition Majority of fetal growth occurs in the last trimester 1 3 of pregnancy Nutrition during this time is important 4 Litter Size Larger litters smaller fetuses 5 Ambient Temperature High temperatures result in smaller fetuses Lower temperatures result in larger fetuses 6 Fetal Hormones Insulin and growth hormones
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