For: ADVS 1110 Introduction to Animal Science ANIMAL REPRODUCTION For: ADVS 1110 Introduction to Animal Science
Farm Animal Reproduction is About a Full Understanding of the Roles and Missions of:
Farm Animal Reproduction – Major Topics: General Reproduction Hormones & Endocrinology Female Reproduction Male Reproduction Conception Pregnancy & Parturition Artificial Insemination Embryo Transfer
Reproduction - Hormones Hormones are chemical mediators produced by the endocrine glands that regulate the function of target organs in another part of the body.
‘Negative Feed-Back’ Mechanism Between the Target Hormone and the Parent Secretory Units
Reproduction - Hormones Endocrine Feedback with CL Present.
Reproduction - Hormones Reproductive Hormones are Produced by the: Pineal Gland (photoperiod) Seasonal Breeders Hypothalmus Pituitary Gland Ovaries Testes Placenta
Reproduction - Hormones Hormones regulate all of the critical steps in successful reproduction in both sexes, including: Puberty Ovulation Transport of Sperm and Ova
Reproduction - Hormones In the female reproductive tract hormones regulate: Maintenance of Pregnancy Parturition
Reproduction - Hormones In the male, hormones regulate: Puberty Sperm Production Development and Maintenance of Accessory Sex Glands Secondary Sex Characteristics Libido
Reproduction - Hormones Glands & Hormones Affecting Reproductive Processes – Summary: Gland Secreting Hormone Name of Hormone Function of Hormone Anterior Pituitary FSH (follicle stimulating hormone) 1. Initiates follicular growth (oogenesis) 2. Influence spermatogenesis 3.Synthetic products (Ovagen, Folltropin) LH (luteinizing hormone) 1. Stimulates growth of tissues in gonads which secrete hormones 2. Acts with FSH to cause ovulation. 3. Causes corpus luteum formation
Reproduction - Hormones Glands & Hormones Affecting Reproductive Processes – Summary: Gland Secreting Hormone Name of Hormone Function of Hormone Anterior Pituitary Prolactin 1. Ovary: maintains functional capacity of the corpus luteum 2. Mammary gland: stimulates formation of milk in alveoli 3. Causes broodiness in birds
Reproduction - Hormones Glands & Hormones Affecting Reproductive Processes – Summary: Gland Secreting Hormone Name of Hormone Function of Hormone Posterior Pituitary Oxytocin 1. Uterus: stimulates contraction (birth, avian egg laying) 2. Mammary gland: initiates let-down of milk into ducts and cisterns
Reproduction - Hormones Glands & Hormones Affecting Reproductive Processes – Summary: Gland Secreting Hormone Name of Hormone Function of Hormone Ovary (Follicle) Estrogen 1. Stimulates growth of accessory reproductive organs and secondary sex characteristics 2. Induces estrus (heat) 3. Mammary gland: stimulates development of the duct system
Reproduction - Hormones Glands & Hormones Affecting Reproductive Processes – Summary: Gland Secreting Hormone Name of Hormone Function of Hormone Ovary (Corpus Luteum) Placenta Progesterone 1. Inhibits release of FSH & LH 2. Prepares uterus for implantation 3. Maintains pregnancy 4. Mammary gland: develops alveolar system 5.Synthetic product (CIDR and Regumate)
Reproduction - Hormones Glands & Hormones Affecting Reproductive Processes – Summary: Gland Secreting Hormone Name of Hormone Function of Hormone Cervix Relaxin 1. Relaxes pubic bones and cervix (birth) Testes Androgen (Testerone) 1. Stimulates sexual desire 2. Stimulates growth of accessory reproductive organs and secondary sex characteristics
Reproduction - Hormones Glands & Hormones Affecting Reproductive Processes – Summary: Gland Secreting Hormone Name of Hormone Function of Hormone Hypothalmus Gonadotrophin-Releasing Hormone (GnRH) Causes release of FSH and LH from anterior pituitary Synthetic products (Cystorelin, Fertagyl, Factrel, OvaCyst) Uterus Prostaglandin F2 alpha Causes regression of corpus luteum in sheep, cattle and swine Synthetic products (Lutalyse, ProstaMate, Estrumate, In-Synch, estroPLAN)
The Reproductive Cycle of Farm Animals
Farm Animal: Female Reproduction
Reproduction - Female Successful livestock production depends upon obtaining the optimum number of viable offspring per year from each producing female:
Reproduction - Female Beef & Dairy Cattle Giving birth to one offspring per pregnancy Efficient reproduction means obtaining a calf each year from as many cows as possible.
Reproduction - Female Sheep & Goats: Obtaining more than one lambing/kidding per year, if possible, or At least two lambs/kids per ewe per year.
Reproduction - Female Swine: Two litters per year, Having at least 8-9 piglets weaned per farrowing
Reproduction - Female Poultry (laying hens): The highest number of eggs per hen per year, Or minimally 285 eggs per year.
Reproduction - Female For high reproductive efficiency, farm animals should: Reach puberty at an early age. Possess high levels of fertility and/or fecundity. Raise a high proportion of their offspring.
Reproduction - Female CURRENT ESTIMATES OF REPRODUCTIVE EFFICIENCY IN FARM ANIMALS ANIMAL STANDARD OF PERFORMANCE* ESTIMATE OF CURRENT PERFORMANCE ATTAINABLE PERFORMANCE Dairy Cattle Calving Interval 14-14.5 months 12-13 months Beef Cattle Calf Crop/Cow/Year 75-82% 90%+ Sheep Lambs Weaned/Ewe/Year 1.01 3.0+ Swine Pigs Marketed/Sow/Year 13.5 20+ Chickens Eggs Laid/Year 235 285+ Turkeys 97 130+ *Commonly used standards of reproductive performance.
Reproduction - Female GESTATION LENGTH AND NUMBER OF OFFSPRING BORN: Gestation Length in Days Usual Number of Offspring Born Cow (cattle) 283 1 Ewe (sheep) 150 1 – 3 Mare (horse) 346 Sow (swine) 115 6 – 14 Doe (goat) 2 – 3 Doe (rabbit) 31 4 – 8 Jill (mink) 50 4 Queen (cat) 52 Bitch (dog) 60 7
Reproduction - Female Anatomy: Cow Tract Side View
Reproduction - Female
Reproduction - Female Anatomy: Cow Reproductive Tract.
Reproduction - Female Cow Reproductive Tract
Reproduction - Female Reproductive Tracts of Ewe, Sow & Mare:
Reproduction - Female Anatomy: Side view of the sow reproductive tract.
Reproduction - Female Anatomy: Side View of the Sow Reproductive Tract: Ovary Follicles Oviduct Body of Uterus Cervix Os Cervix & Fornix Vagina Sub-urethral Diverticulum Bladder
Reproduction - Female
Reproduction - Female Gilt Reproductive Tract
Reproduction - Female Anatomy: Ewe Tract
Reproduction - Female Anatomy: Mare Reproductive Tract
Reproduction - Female Anatomy: Mare Reproductive Tract
Reproduction - Female Anatomy: Avian (hen) Reproductive Tract
Reproduction - Female
Reproduction - Female Avian Reproductive Tract:
Reproduction - Female Avian Reproductive Tract:
Reproduction - Female Avian Reproductive Tract:
Reproduction - Female Avian Reproductive Tract:
Reproduction - Female Ovary Diagram: Not all present at once
Reproduction - Female Ovary - Cow Ovary - Sow
Reproduction - Female Estrous Cycle = Anestrus + Estrus Seasonally Polyestrous: Ewe Doe Mare Polyestrous: Cow Sow
Reproduction - Female
Reproduction - Female Endocrine Control of Female Mammalian Reproductive Cycle:
Reproduction - Endocrinology
Reproduction - Female Hormonal Control of the Estrous Cycle
Reproduction - Female Ovary Through Estrous Cycle:
Reproduction - Female Estrous Cycle:
Cow: Rise & decline of reproductive hormones during a typical 21-day estrous cycle
Reproduction - Hormones
Reproduction - Hormones
Reproduction - Female Cow in Estrus (Heat).
Reproduction - Female Ewe in Estrus (Heat):
Reproduction - Female Sow in Estrus (Heat):
Reproduction - Female Mare in Estrus (Heat):
Length of Estrous Cycle; Duration of Heat; and Time of Ovulation Species Average Days in Cycle Duration of Heat (hr) Time of Ovulation Suggested Time of Mating Cow 21 12–18 12–15 hr after estrus 4–8 hr before end of estrus Sow 48–72 18–40 hr after start of estrus 24 hr after start of estrus Ewe 17 24–36 18–26 hr after start of estrus 12–18 hr after start of estrus Doe 34–39 9–19 hr after start of estrus Mare 22 4–8 (days) 24-48 hrs prior to end of estrus Alternate days during estrus
Characteristics of Estrus & Estrous Cycles of Farm Animals Trait Dairy Cattle Beef Cattle Sheep Goats Swine Horses Average age at puberty, males (days) 275 (225-325) 300 (250-350) 150 (120-185) (120-180) 200 (150-240) 455 (300-730) Average age at puberty, females (days) 330 (300-360) 390 (320-460) (140-240) 180 (120-210) 210 (115-250) 540 Estrous cycle type Polyestrous Seasonal Polyestrous Average length of estrous cycle (days) 21 (17-24) 17 (14-19) (18-23) (19-23) 22 (18-24) Average length of estrus (hrs) 15 (12-20) 20 (12-30) 30 (18-40) 34 (26-42) 56 (40-70) 7 days (2-11 days) Time of ovulation after onset of estrus 28 hr 30 hr 24 hr 36 hr 40 hr 5 days Usual no. of follicles ovulated 1 1-6 1-4 13-22