02572naa a2200361 a 450000100080000000500110000800800410001910000210006024501700008126000090025150001930026052012920045365000210174565000240176665000100179065000110180065300150181165300320182665300220185865300170188065300190189765300150191665300180193165300200194970000180196970000160198770000250200370000160202870000280204470000210207270000220209377300950211520979472018-10-23       2018    bl uuuu     u00u1 u    #d1 aRAVAGNANI, G. M.  aCryopreservation of boar semen in 0.5mL straws at low spermatozoa concentration is better than high concentration to maintain sperm viability.h[electronic resource]  c2018  aTítulo em português: A manutenção da viabilidade do sêmen suíno criopreservado em palhetas de 0,5mL em baixas concentrações espermáticas é melhor do que em altas concentrações.  aTo date, no studies have been performed evaluating the effect of boar spermatozoa concentration in 0.5mL freezing straws, leading us to examine this question. Each sperm‑rich fraction of the ejaculate (n=25) was diluted at five different sperm concentrations (100, 200, 300, 600 and 800 x 106 spermatozoa/mL), packaged in 0.5mL straws, and subsequently frozen. After thawing, the sperm from all of treatment groups were analyzed to determine motility characteristics using a sperm class analyzer (SCA-CASA), and their plasma and acrosomal membrane integrity, mitochondrial membrane potential, sperm membrane lipid peroxidation and fluidity were analyzed by flow cytometry. An increase in spermatozoa concentration above 300x106 spermatozoa/mL in a 0.5mL straw impaired (p&lt0.05) the total and progressive motility, curvilinear velocity, straight-line velocity, linearity and beat cross frequency. However, the plasma and acrosomal membrane integrity, mitochondrial membrane potential, membrane lipid peroxidation and fluidity were not influenced (p&gt0.05) by high spermatozoa concentrations at freezing. Therefore, to increase spermatozoa survival and total and progressive motility after thawing, boar spermatozoa should be frozen at concentrations up to 300x106 spermatozoa/mL.  aCryopreservation  aSperm concentration  aSwine  aSuíno  aBoar semen  aConcentração espermática  aCriocapacitação  aCrioinjúria  aCriopreservão  aCryoinjury  aSêmen suíno  aSperm viability1 aTORRES, M. A.1 aLEAL, D. F.1 aMARTINS, S. M. M. K.1 aPAPA, F. O.1 aDELL'AQUA JUNIOR, J. A.1 aALVARENGA, M. A.1 aANDRADE, A. F. C.  tPesquisa Veterinária Brasileira, Rio de Janeirogv. 38, n. 9, p. 1726-1730, setembro 2018