Department - Author 1

Dairy Science Department

Degree Name - Author 1

BS in Dairy Science



Primary Advisor

Stan Henderson


As dairy herd sizes increase, dairymen often initiate systematic breeding programs on their dairy in order to improve their reproduction efficiency. The objective of this study, compares systematic breeding program by comparing reproductive efficiency between two systematic breeding programs Target Breeding (January 1, 2008 to May 31,2009) and Presynchronization (Presynch) Program (January 1, 2010 to May 31, 2011) at a large central valley dairy. The traditional Target Breeding program is a systematic breeding program that is solely prostaglandin (PGF) based. The more modern Presynch programs includes both Gonadotropin Releasing Hormone (GnRH) and PGF, that allows for both superovulation and estrus synchronization. The dairy’s herd size is 1500 milking cows. Data was collected from DHI-Plus management software for both two systematic breeding programs. The data compared was the 21 d pregnancy rate, conception rates, and 1st service conception rates. The results of this study state that the Presynch Program was more efficient in all the areas observed during this study. The Presynch Program showed higher averages in 21 d pregnancy rate, conception rates and 1st service conception rates.

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Dairy Science Commons