02888naa a2200301 a 450000100080000000500110000800800410001902200140006002400360007410000180011024502000012826000090032850004570033752014410079465300190223565300150225465300290226965300110229865300270230970000160233670000190235270000180237170000170238970000140240670000190242070000170243977301300245610635852022-09-27       2022    bl uuuu     u00u1 u    #d  a0049-47477 a10.1007/s11250-022-03308-22DOI1 aSINCHI, F. I.  aAddition of clinoptilolite in the diet reduces uterine PMN leukocytes and open days in multiparous lactating dairy cows managed in a mountain tropical pasture-based system.h[electronic resource]  c2022  aArticle history: Received 17 June 2021; Accepted 31 August 2022; Published online 08 September 2022. Corresponding author: Perea, F.P.; Carrera de Medicina Veterinaria y Zootecnia, Facultad de Ciencias Agropecuarias, Universidad de Cuenca, Cuenca, Ecuador; email:fernando.perea@ucuenca.edu.ec  --  Funding: This study was supported by the Vice-Rectorate for Research of the University of Cuenca (VIUC), Ecuador, throughout project DIUC-XIV-2016?022. --  aABSTRACT.- This study aimed to assess the effect of adding clinoptilolite in the diet on uterine health and reproductive performance in multiparous lactating dairy cows managed in a tropical pasture-based system above 2500 m of altitude. Seventy-seven multiparous Holstein crossbred cows from two farms were allocated randomly into two groups: clinoptilolite supplemented cows (CLG, n = 42) and non-supplemented cows as control (CG, n = 35). Cows from CLG were supplemented with clinoptilolite from 30 days (50 g/cow/day) before to 60 days after calving (200 g/cow/day). In CLG cows, percentages of uterine PMN leukocytes (P < 0.0001) and proportion of subclinical endometritis (P = 0.0187) were lower than in CG. The interval calving to first corpus luteum was shorter (P = 0.0759) in CLG than CG, and calving to first service interval was similar between treatments. Cows from CLG became pregnant 35 days earlier than CG cows (P = 0.0224). On farm A, calving to conception interval was 18.1 days longer in CLG than in CG (P = 0.3750); in farm B, this interval was 86.2 days shorter in CLG than in CG (P = 0.0002). In conclusion, daily addition of clinoptilolite in the diet decreased the percentage of uterine PMN leukocytes, the proportion of cows with subclinical endometritis, and shortened the calving-conception interval in multiparous lactating dairy cows. © 2022, The Author(s), under exclusive licence to Springer Nature B.V.  aClinoptilolite  aDairy cows  aReproductive performance  aTropic  aUterine PMN leukocytes1 aZUIN, J. F.1 aGARZÓN, J. P.1 aLÓPEZ, G. E.1 aCALLE, G. R.1 aQUITO, F.1 aGALARZA, D. A.1 aPEREA, F. P.  tTropical Animal Health and Production, 2022, Volume 54, Issue 5, Article 281. doi: https://doi.org/10.1007/s11250-022-03308-2