AN_SCI 1001 Lecture Notes - Lecture 6: Heritability, Debt Management Plan, Nipple
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= estrous cycle control: pgf2a, gnrh, progesterones. Prostaglandin f2a commonly used to bring a cow into estrous. causes the cl to regress heat in heifers 2-3 days after treatment, 3-5 in cows. Number of pregnant animals / number seen in heat and ai. Typically about 50-60% for dairy heifers after one ai. # of pregnant animals / total # that you were trying the breed. Typically lower than cr bc some animals are never seen in heat. 3 reasons you wont see a heifer in heat: prepubertal (no cl, freemartin ( born twin to a bull so she is sterile, pregnant (treating with pgf2a will cause abortion) Why are cows harder to get pregnant that heifers (1 in 3 vs. 1 in 2) low progesterone irregular estrous cycles: poor estrous expression, disease to uterus from previous calving, size and metabolism. The longer a cow is in heat, the ____ kg of milk will be produced per day.
