- Slim Maverick Ace S Brother Runs Commercial Cattle Just South Of Ace S Place Slim Wants To Improve The Probability Of 1 (92.18 KiB) Viewed 30 times
Slim Maverick, Ace's brother, runs commercial cattle just south of Ace's place. Slim wants to improve the probability of
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Slim Maverick, Ace's brother, runs commercial cattle just south of Ace's place. Slim wants to improve the probability of
Slim Maverick, Ace's brother, runs commercial cattle just south of Ace's place. Slim wants to improve the probability of conception (PC) in his year- ling heifers. But conception is an all-or-none threshold trait for which Slim can achieve little selection intensity. The bulls that Slim buys have EPDS for scrotal circumference (SC), a trait known to be related to heifer conception rate. Slim is contemplating two strategies: (1) practicing phenotypic selection for probability of conception by retaining only those heifers that conceive in their first season, and (2) selecting bulls for scrotal EPD. The following ge- netic parameters have been estimated for these traits: hpc = .10 hc=.5 PPC = 46 PSC = 2.0 cm BVSC BV PC Assume: Slim breeds all his heifers and keeps 40% for replacements. Typical heifer conception rate is 70%. = .25 The bulls that Slim buys represent the equivalent of the top 5% of his herd for scrotal circumference. Accuracy values for scrotal circumference EPDs average .9. Lm = L = 5 years a. Calculate annual selection response in probability of heifer conception us- ing strategy 1. b. Calculate annual selection response in probability of heifer conception us- ing strategy 2. c. Which strategy works better? Why?