Department - Author 1

Dairy Science Department

Degree Name - Author 1

BS in Dairy Science



Primary Advisor

Leanne Berning


As the Dairy industry evolves year by year it is becoming ever more important to be reproductively efficient. The implementation of various timed artificial insemination (TAI) programs has become very common in order to maintain reproductive stability throughout the herd. This can be harder than ever with the increase of herd sizes and hot summer temperature in the central valley. The objective of this study compares two ovsynch breeding programs during summer months on a large central valley dairy. The change in protocol was a delayed 100% timed artificial insemination at approximately 70 dim for the 5-month period from June to October 2012 when cows are most susceptible to heat stress. The delayed ovsynch protocol was implemented to observe the effect upon maintaining the 21-day pregnancy rate, conception rate, and 1st service conception rates throughout the summer months. The dairy’s herd size is 3,500 milking cows and all data was collected from Dairy Comp 305 for both breeding programs. The results of this study show that the delayed 100% TAI breeding program during the summer months was more efficient in all of the areas observed. The herd maintained a higher 21-day pregnancy rate throughout the 5-month period and recorded a 3% rise in conception and 1st service conception.

Included in

Dairy Science Commons