ADSC 2010 Lecture 27 Outline of Last 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 Outline of Current Lecture I Reproduction Post Partum Estrus A Cattle B Ewe C Sow D Mare II Management of the Reproductive Tract III Estrus in the Female IV Estrus Detection Current Lecture I Reproduction Post Partum Estrus A Cattle a Dairy 30 70 days b Beef 45 105 days Suckling or increased frequency of milking will delay the first estrus after calving Take calf away from cow for a day to stimulate estrus Anestrus not cycling II III Estrus time ovulating receptive B Ewe Seasonal breeders Shorter days stimulate estrus fall winter Considerable variation C Sow Anovulatory estrus 1 3 days not ovulating Don t usually cycle during lactation Wean pigs functional ovulatory estrus o 5 7 days post weaning to first ovulatory estrus D Mare Seasonal breeders Foal heat 5 15 days after birth Functional because long gestation period ovulation To maintain annual production can breed o Requires more care Longer days stimulates estrus spring May show signs all year Seasonal breeding target production of offspring before growth flush of food Management of the Reproductive Tract A Estrus Synchronization B Artificial insemination AI Utilize superior genetics increases quality cheaper rate C Embryo Transfer Female produces large numbers of fertilized embryos put into another female D Pregnancy Detection Estrus in the Female A Signs of Estrus a Cow o Swelling redness of vulva o Restlessness vocalization o Rides herdmates typical Bos cow o Stands to be mounted o Clear mucous discharge b Ewe o Few signs except standing to be ridden by mate c Sow o o o o o IV Swelling redness of vulva Restless vocalization Mounting other sows Stands to be mounted Stands to hand pressure pressure on back responds accordingly if in heat o Erect ears d Mare o Nervousness o Frequent urination squatting o Winking of vulva o Stands for male Estrus Detection A Cow o Visual observation am pm o Marker animal chin ball marker o Female Androgen treated o Male vasectomized penectomized penile deviated o Heat detection patches KMAR Patch o Heat Watch electronic detection system B Ewe o Vasectomized ram with breast marker marking harness C Sow o Boar exposure hand pressure D Mare o Teasing with a stallion note acceptance or rejection not always safe stallion can get aggressive Sometimes use pony stud easier to manage try to have some kind of separation If not in estrus female may try to kill
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