Bovine pregnancy rates have been decreasing, causing economic hardship in the dairy industry. A simple, quick and inexpensive diagnostic method to determine ovarian follicular phase and optimal breeding times is needed. The hypothesis of this randomized controlled study was that the XXH-IIA Acupoint Diagnosis and Therapeutic Instrument (developed by the Lanzhou Institute of Husbandry and Pharmaceutics Science) would be useful to diagnose phases of follicular development and treat acupoints, altering hormone levels and improving pregnancy rates in cows. The resistance was measured bilaterally at acupoints Shen-pang and Yan-pang (new bovine acupoints described by the authors) and the classical acupoint Luan-chao. Very significant unbalanced resistance between left and right acupoints (p<0.01) were found for Yang-pang during phase 2, Luan-chao during phase 3 and Shen-pang during phase 4, but not in cows with inactive ovaries. Electro-stimulation of Shen-pang and Yan-pang produced a significant increase in serum 17β- estradiol levels (p<0.05) 20 minutes after electro-stimulation in 14/25 cows (56%) and 13/42 cows (31%) respectively. Electro-stimulation of Shen-pang and Luan-chao produced a significant increase in serum progesterone levels (p<0.05) in 7/20 cows (35%) and 9/13 cows (69.2%), 20 minutes after electro-stimulation, with a trend to develop peak levels in 3-7 hours. Unilateral electro-stimulation of Shen-pang or Yan-pang (cows in phase 2 or 4 respectively) very significant increased the pregnancy rate (p=0.001) in 200 cows compared to 130 controls. Evaluation of bilateral low resistance characteristics and electro-stimulation of Shen-pang, Luan-chao or Yan-pang may be an effective diagnostic and treatment method to improve fertility in cows.