ISI Impact Factor (2004): 1.096

Editor-in-Chief
Prof. Yi-Fei WANG,

Seminal concentrations of trace elements in various animals and their correlations

P. Massányi¹, J. Trandzik², P. Nad³, R. Toman¹, M. Skalická³, B. Koréneková³

¹Department of Animal Morphology, Slovak University of Agriculture, SK-94976 Nitra, Slovak Republic
²State Breeding Institute, SK-94992 Nitra, Slovak Republic
³Research Institute of Veterinary Medicine, University of Veterinary Medicine,SK-040 01 Košice, Slovak Republic

Asian J Androl 2003 Jun; 5:  101-104             

Keywords: semen; copper; zinc; iron; cadmium; lead; nickel

Abstract

Aim: To determine the seminal concentrations of copper, zinc, iron, cadmium, lead and nickel in bulls, rams, boars, stallions and foxes and study their correlations. Methods: Semen samples were obtained, digested and analyzed by means of the atomic absorption spectrophotometer. Data were analyzed statistically with the Student's t-test and Scheffe's test using PC programs SAS and Excel. Results: The seminal copper concentration was significantly higher in ram [(2.49±0.18) mg/kg] and fox [(2.16±0.53) mg/kg] than that in bull [(1.64±0.21) mg/kg], boar [(1.64±0.28) mg/kg] and stallion (0.86 mg/kg). In boar a significantly higher seminal zinc concentration (171.74±65.72) mg/kg] was found in comparison with stallion [(86.20±45.88) mg/kg], bull [(83.15±61.61) mg/kg], ram [(60.46±35.37) mg/kg] and fox (13.09±5.22) mg/kg]. The iron concentration in semen was significantly higher in ram [(40.32±10.81) mg/kg), bull [(38.04±22.07) mg/kg] and fox [(33.16±24.36) mg/kg] than that in boar [(16.14±010.35) mg/kg] and stallion (12.68 mg/kg). The seminal cadmium concentration was relatively low [(0.05~0.12) mg/kg] in all studied species. The seminal lead concentration was the highest in ram [(0.35±0.68) mg/kg], which was much higher than in fox [(0.08±0.06) mg/kg], bull [(0.06±0.04) mg/kg], stallion [(0.05±0.05) mg/kg] and boar [0.02±0.03) mg/kg]. The level of seminal nickel was significantly higher in fox [(0.35±0.24) mg/kg] and ram [(0.31±0.19) mg/kg] in comparison with bull [(0.12±0.07) mg/kg] and boar [(0.06±0.08) mg/kg]. The concentration of nickel in the semen of stallion was (0.20±0.24) mg/kg. There was a high positive correlation between seminal iron and zinc in bull (r=0.723) and stallion (r=0.723), between cadmium and lead in ram (r=0.976) and boar (r=0.973) and between iron and cadmium (r=0.783) and iron and lead (r=0.791) in boar. A high negative correlation between seminal nickel and copper in ram (r=-0.709) and between seminal copper and lead in fox (r=-0.854) was found. Conclusion: There are significant differences in the concentrations of seminal elements in different animals. There is a high concentration of seminal copper in ram and fox, a high zinc level in boar, a high iron level in bull, ram and fox and a high nickel level in ram and fox.

1 Introduction

Essential trace elements, zinc and copper, are involved in carbohydrate and lipid metabolism and in immune function [1]. Copper has a　multple function, as iron absorbtion, haemopoiesis, various enzyme activities and in the oxidation-reduction process [2]. Zinc deficiency results in disorders of testicular development and spermatogenic failure [3, 4]. The biological role of lead is not clear, but its accumulation in tissues may cause health hazards [5]. Though abnormal sperm chromatin structure is not related to blood lead concentration, some indications of deterioration of sperm chromatin was found in men with high concentrations of lead within sperma-tozoa, however, long term effects of lead on semen quantity or sperm chromatin was obscure [6]. Exposure to cadmium may lead to harmful effects on the kidney and reproduction, causing ovarian follicular atresia [7], uterine edema [8] and testicular degeneration [9]. Nickel damages the testicular, seminal vesicular and prostatic functions [10-12].

In goats, copper, calcium, nickel, iron, magnesium, chromium, titanium and zinc were present in the epididymal lumen, with fluctuating levels at different sites along the length of the epididymis, while cadmium, cobalt, lead and manganese were not found [13].

The purpose of this study was to determinate the seminal copper, zinc, iron, cadmium, lead and nickel concentrations in bulls, rams, boars, stallions and foxes and to explore the correlation among these elements.

2 Materials and methods

2.1 Animals and semen samples

Semen samples were obtained from adult bulls (n=200), rams (n=100), boars (n=20), stallions (n=10) and foxes (n=10). Semen was processed at the animal breeding station (State Breeding Institute, Nitra, Slovak Republic) to frozen-thawed pellets (bulls, rams, foxes), frozen-thawed insemination tubes (stallions) and in natural status (boars).

2.2 Semen analysis

Semen samples were digested in a microwave oven (MLS-1200 MEGA, Milestone, USA) using 5 mL HNO₃ and 1 mL HCl/g sample. The digested samples were analyzed for copper, zinc iron, cadmium, lead and nickel by means of an atomic absorption spectrophotometer (Unicam Solar 939, USA). The flame conditions were those recommended by the instrument manufacturer for copper, zinc iron, cadmium, lead and nickel (wavelength 324.8 nm, 213.0 nm, 248.3 nm, 228.8 nm, 283.3 nm and 232.0 nm, respectively, band pass 0.5 nm). The quantification limit for copper, zinc and iron were 0.096 mg/L, 0.13 mg/L and 0.12 mg/L, respectively, and the detection limits, 0.29 mg/L, 0.0036 mg/L and 0.039 mg/L, respectively. The quantification limits for cadmium, lead and nickel were 0.03 mg/L, 0.27 mg/L and 0.22 mg/L, respectively, and the detection limits, 0.01 mg/L, 0.08 mg/L and 0.065 mg/L, respectively.

Analyzing reference materials (MBH Anal. Ltd., UK) were employed to test the reproducibility of the method. The graphite furnaces were optimized for maximum absorbancy and linear response while aspirating known standards. The standards were prepared from the individual 1,000 mg/kg standard (Merck, Germany) and 100 mL of five combined standards were prepared in 0.1 mol/L HNO3. The lamp current used was 75 %. The signal type was transient for copper, zinc and iron. The measurement time was 3 sec. The recovery of the methods was 96 %~98 % and reproducibility was higher than 1.0 %. All metal concentrations were expressed in mg/kg wet weight of the tissue.

2.3 Statistical analysis

Data were expressed in mean±SD and analyzed statistically with Student's t-test, Scheffe's test and Pearson's rank using PC programs SAS and Excel. P<0.05 was considered significant.

3 Results

The seminal copper concentration was significantly higher (P<0.01) in rams than that in bulls, boars and stallions, in bulls and boars than that in stallions, in foxes than in stallions, and in bulls than that in boars. The seminal zinc concentration was significantly higher (P<0.01) in boars than that in other 4 animals. The lowest level of zinc was found in fox. The seminal iron concentration was significantly higher (P<0.05) in bulls than that in stallions, in rams than that in boars and stallions, and significantly higher (P<0.01) in bulls than that in boars. The seminal nickel concentration was significantly higher (P<0.05) in foxes than that in bulls, and significantly higher (P<0.01) in rams and foxes than that in boars. The concentration of seminal cadmium was low in all the animals and without any significant difference between them. The highest seminal concentration of lead was found in rams and low in foxes, bulls, stallions and boars (Table 1).

Table 1. Seminal concentrations (mg/kg) of trace elements in different animals. Copper: P<0.01 (ram vs bull, boar and stallion; bull vs stallion; boar vs stallion; fox vs stallion, bull and boar). Zinc: P<0.01 (boar vs fox; boar vs bull and ram; boar vs stallion). Iron: P<0.05 (bull vs stallion; ram vs boar and stallion); P<0.01 (bull vs boar). Nickel: P<0.05 (fox vs bull); P<0.01 (ram vs boar; fox vs boar).

Correlation analysis (Table 2) indicated a high positive correlation between seminal iron and zinc in bull (r= 0.723) and stallion (r=0.723), between seminal cadmium and lead in ram (r=0.976) and boar (r=0.973) and between seminal iron and cadmium (r=0.783) as well as between seminal iron and lead (r=0.791) in boar. A high negative correlation was found between seminal nickel and copper in ram (r=-0.709) and between seminal copper and lead in fox (r=-0.854).

Table 2. Correlation analysis of trace elements in studied species. ^bP<0.05, ^cP<0.01.