145 Effect of Dietary Organic Zinc Levels on Boar (Sus scrofa domesticus) Sperm DNA Fragmentation Dynamics
A. Martínez A , J. Gosálvez B , C. López-Fernández B , J. A. G. González C , C. G. Artiga D , Y. D. L. Ortega D , M. E. Kjelland E and A. García-Contreras AA Laboratorio de Imagenología Lic. MVZ, Universidad Autónoma Metropolitana-Unidad Xochimilco, Xochimilco, México DF, México;
B Área de Genética, del Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain;
C Medicina Veterinaria y Zootecnia, Facultad de Estudios Superiores-Cuautitlán, Cuautitlán, Estado de México, México;
D Facultad de Veterinaria, Departamento de Fisiología (Fisiología Animal), Universidad Complutense de Madrid, Madrid, Spain;
E Conservation, Genetics & Biotech LLC, Vicksburg, MS, USA
Reproduction, Fertility and Development 30(1) 212-212 https://doi.org/10.1071/RDv30n1Ab145
Published: 4 December 2017
Abstract
Zinc (Zn) is essential for the development and activity of sperm, although its cytotoxic effect on sperm has been little studied. This study evaluated the effect of organic Zn; that is, Zn-methionate (Zn-Met), on the DNA fragmentation of boar sperm. Domestic boars (York × Landrace, Sus scrofa domesticus; n = 15) were randomly allocated into 3 levels of Zn dietary concentrations: 25 (Control), 150, or 200 ppm. Sperm DNA fragmentation dynamics were evaluated over an 8-wk period after Zn-Met supplementation. The Sperm-Sus-Halomax® Kit (Halosperm SL, Madrid, Spain), a 1:1 mixture of SYBR I (10×; Invitrogen Molecular Probes, Thermo Fisher Scientific, Waltham, MA, USA) in Vectashield Mounting Medium (Vector Laboratories Inc., Burlingame, CA, USA) for DNA staining, and fluorescence microscopy (Nikon Eclipse 80i; Nikon, Tokyo, Japan) were used to analyse DNA fragmentation dynamics; that is, sperm chromatin dispersion (SCD) test, of the boar sperm. Samples were diluted 2:10 (v:v) in either (a) Beltsville Thawing Solution (BTS) extender, or (b) PBS, to determine the effects, if any, of extender. Extended sperm were stored at 15°C for 8 days for daily SCD testing. Data were analysed as a completely randomised design with repeated-measures serially in time (SAS Institute Inc., Cary, NC, USA). Main effects of the variables (i.e. dietary Zn and extender) and their interaction were studied. Means were compared using Tukey´s test, with significance set at the <0.05 α-level. Supplementation of the diet with 200 ppm of Zn-Met had an adverse effect on the integrity of pig sperm DNA from the beginning of supplementation to the last day of the experiment (i.e. fresh ejaculate 0 h = 9.44% fragmented, motility = 79.6%). However, Control and 150 ppm Zn-Met dietary levels did not significantly affect sperm DNA integrity (i.e. fresh ejaculate 0 h = 1.43% and 1.73% fragmented and motility = 84.1% and 84.5%, respectively). With regard to the semen extenders BTS and PBS, there was no difference (P > 0.05) in sperm DNA fragmentation dynamics for the first 3 days in extender: Day 3 = 4.09 and 6.45%, respectively. However, the sperm DNA fragmentation index was different (P < 0.05) between extenders BTS and PBS based on extended sperm for Day 4: 4.28 and 7.28%, respectively, through Day 8 (5.52 and 10.02%). These results demonstrated the importance of providing the correct amount of organic Zn in boar diets and potential impacts on reproduction.
