پردیس کشاورزی و منابع طبیعی دانشگاه تهران Iranian Journal of animal Science 2008-4773 51 4 2021 02 19 Effect of high dietary zinc, copper and manganese concentration and source on ‎plasma progesterone and reproductive performance in repeat breeder cows Effect of high dietary zinc, copper and manganese concentration and source on ‎plasma progesterone and reproductive performance in repeat breeder cows 263 273 80520 10.22059/ijas.2020.305609.653786 FA Vahid Gholami Ph.D. Candidate, Faculty of Agriculture, University of Zanjan, Zanjan, ‎Iran Hamid Amanlou Professor, Faculty of Agriculture, University of Zanjan, Zanjan, Iran 0000-0002-5631-125X Davood Zahmatkesh Associate Professor, Faculty of Agriculture, University of Zanjan, Zanjan, Iran Nima Sadeghi DVM, PhD in FKA Animal Husbandry and Agriculture Co., Irsfahan, Iran‎ Journal Article 2020 07 07 We used 263 Holstein repeat breeder dairy cows (193±58 DIM) based on randomized complete design. Animals in control group (no supplementation), groups 2 and 3 supplemented with 2,244 mg of zinc, 295.5 mg copper and 480 mg manganese either inorganic trace minerals (ITM) and chelated (glycinates) trace minerals (CTM) sources, respectively. Supplemental minerals were fed daily as a top dress. All cows were inseminated according to Double-Ovsynch protocol. Super oxide dismutase concentration tended to have higher in CTM and ITM treatments than in control group (<em>P</em>=0.09). Progesterone concentration at day 11 after artificial insemination was higher in CTM and ITM treatments than in control group (<em>P</em><0.05). Cows in CTM and ITM treatments tended to have greater odds of becoming pregnant at first and cumulative (first and second service) than cows in control group (P=0.1 and P=0.13 respectively). According to the results of this study, diets supplemented above National Research Council (NRC, 2001) requirments for zinc, copper and manganese in repeat breeding cows, improved fertility. We used 263 Holstein repeat breeder dairy cows (193±58 DIM) based on randomized complete design. Animals in control group (no supplementation), groups 2 and 3 supplemented with 2,244 mg of zinc, 295.5 mg copper and 480 mg manganese either inorganic trace minerals (ITM) and chelated (glycinates) trace minerals (CTM) sources, respectively. Supplemental minerals were fed daily as a top dress. All cows were inseminated according to Double-Ovsynch protocol. Super oxide dismutase concentration tended to have higher in CTM and ITM treatments than in control group (<em>P</em>=0.09). Progesterone concentration at day 11 after artificial insemination was higher in CTM and ITM treatments than in control group (<em>P</em><0.05). Cows in CTM and ITM treatments tended to have greater odds of becoming pregnant at first and cumulative (first and second service) than cows in control group (P=0.1 and P=0.13 respectively). According to the results of this study, diets supplemented above National Research Council (NRC, 2001) requirments for zinc, copper and manganese in repeat breeding cows, improved fertility. https://ijas.ut.ac.ir/article_80520_9ca3ed1fb34e550227803abc3241875f.pdf