The content of chosen chemical elements in wool of sheep of different origins and breeds

The following chemical elements in sheep wool originating from Poland (Polish Mountain Sheep), Greece (Karagounico breed), and Syria (Awassi breed) were analysed: macroelements (Ca, P, Na, K, Mg, S), trace elements (Al, Ba, Co, Cu, Fe, Mn, Mo, Sr, Ti, Zn) and heavy metals (As, Cd Hg, Pb). Some statistically significant differences were observed between the content of the examined elements in sheep wool collected in the above countries. Sulphur, calcium, sodium and potassium were found in the highest amounts, while arsenic, cadmium and mercury occurred in the lowest quantity.


Introduction
Sheep fleece, similar to other animals' coats, presents a specific chemical indicator, and a concentration of the elements it contains reflects both feed and nutrition quality, as well as climate and the state of the environment.It is obvious that many other factors, such as

Material and methods
The research material was obtained from 3-year-old sheep mothers of a similar performance type (meat-milk) and the same type of coat (mixed wool).The samples were collected in the late summer period when the sheep were in pastures.Sheep were typical for their region of origin.
The Polish material (W-Pl) involved sheep of the Polish Mountain Sheep breed.Those animals can be found across the whole Polish Carpathian region; however, most commonly in Podhale in the region of Nowy Sącz where the collection of samples took place.In Greece, samples (W-Gr) were obtained from the Karagounico sheep breed from the Thessaloniki region.Those sheep are the most characteristic for the lowlands of western Thessaly.The material from Syria (W-Sy) was wool samples from the Awassi sheep breed, commonly occurring in that country, collected in Syria central province of Homs.
Wool samples weighing 12-20 g were collected by cutting them out from the left and right sides of 10 animals representing each of three countries.Then the samples were subjected to cleaning and degreasing processes.Foreign substances and plant parts were separated prior to washing in warm water (50 °C) with detergent.Samples were rinsed twice in distilled water, and then left for natural drying.Samples thus prepared were then subjected to chemical analysis after they had been mineralized using the MARS-5 (CEM, USA) microwave system.100-fold diluted nitric acid (MERCK, Germany) solution was applied.The weight of analytical samples was 0.5 g.A VARIAN LIBERTY type 220 (USA) spectrophotometer was used for analysis.Mercury concentration was determined by a direct method using an analyzer of MA 200 type (NIC Japan).The weight of analytical samples ranged from 100 to 200 mg.In wool samples 6 macroelements (Ca, P, Na, K, Mg, S), 10 trace elements (Al, Ba, Co, Cu, Fe, Mn, Mo, Sr, Ti, Zn ) and 4 heavy metals (As, Cd, Hg, Pb) were analysed.
Analytical analyses were conducted in the Analytical Laboratory of Wrocław University of Environmental and Life Sciences.The results obtained were statistically analysed using the Duncan test to calculate mean values, standard deviations, significance of differences between the groups on Statistica 7.1 software.

Results and discussion
The results of the analyses were presented in tabular format taking into account the division into macroelements, trace elements and heavy metals.All of them, regarding percentage weight, provided for 2.736 % in the wool from Greece (W-Gr), 2.649 % from Poland (W-Pl), and 2.522 % from Syria (W-Sy).

Macroelements
Table 1 shows the results of the analysis of the main macroelements.Calcium (Ca) content ranged from 1 790 to 2 900 mg/kg.The highest amount of Ca was found in the case of W-Gr, while the lowest one in W-Pl (differences significant statistically, P<0.05).Some authors (KROŚNICKA-BOMBAŁA 1996, GABRYSZUK et al. 2000) report the range of this basic macroelement in sheep wool from 645.6 to 1 720.6 mg/ kg, although in the case of ill sheep even an amount of 0.44 % (4 400 mg/kg) (HUANG and CHEN 2001) was detected.Amount of Ca determined by AYDIN (2008) in wool from male lambs collected in Turkey was on a level of 0.41-0.57%.
Phosphorus (P) concentration ranged from 148 to 284 mg/kg.Its highest values were recorded in W-Sy and the lowest content in the case of W-Pl (P<0.05).Some authors (HUANG and CHEN 2001) determine a similar range of this important bioelement concentration, i.e. from 163 to 300 mg/kg.The concentration of sodium (Na) ranged from 1 486.7 to 2 165 mg/kg.The highest amount of this element was observed in the case of W-Gr, while the lowest in W-Pl (P<0.05).Some authors (KROŚNICKA-BOMBAŁA 1996, PATKOWSKA-SOKOŁA et al. 2003) report a very wide range of Na concentrations, i.e. 172.2-1 463.5 mg/kg, while AYDIN ( 2008) reports a content of that element on a level of 0.28-0.36%.Potassium (K) concentration ranged from 643 to 755 mg/kg.Its highest amount was observed in the case of W-Sy, while the lowest one in W-Gr, although the differences were not significant statistically.Certain authors (KROŚNICKA-BOMBAŁA 1996, GABRYSZUK et al. 2000, PATKOWSKA-SOKOŁA et al. 2003, AYDIN 2008) report a relatively wide range of potassium concentrations, i.e. from 204 to 2 499.2 mg/kg.
The determined magnesium (Mg) content was within the range of 120.8 to 590.8 mg/kg.The highest values were noted in the case of W-Sy, and the lowest ones in W-Pl (P<0.05).Some authors (KROŚNICKA-BOMBAŁA 1996, GABRYSZUK et al. 2000) report quite a wide Mg concentration range in sheep hair, i.e. 47.8-263.4mg/kg, while AYDIN (2008) found a content of that element ranged from 0.09-0.13% in wool from male lambs.Sulphur (S) concentration varied within the range of 18 733.4 to 22 038.3 mg/ kg.It was the highest in the case of W-PL, and the lowest in W-Sy (P<0.05).PATKOWSKA-SOKOŁA (1990) determined sulphur concentration in Merino sheep wool at a level of 2.90-3.28%, depending on its supply in animal diet and the season of the year, while other authors (GEORGIEVSKI et al. 1982, HUANG andCHEN 2001) generally report its values from 2.61 % to as much as 4 % (4 000 ppm).

Trace elements
Table 2 presents the results of the analysis of the main microelements.Aluminium (Al) concentration in sheep wool collected in the three countries varied within a wide range of 53.65 to 620.83 mg/kg.The highest amount was found in W-Sy, and the lowest one in W-Pl (P<0.05).
The observed concentration of barium (Ba) ranged from 1.56 to 9.42 mg/kg.The highest amount of this element was found in the case of W-Sy, while the lowest in W-Pl (p<0.05).Some authors (KOŁACZ et al. 1999, PATKOWSKA-SOKOŁA et al. 2003) give a short range of barium content in wool from sheep from different habitats, i.e. 2.146-4.687mg/kg.Generally, in the case of terrestrial animals the concentration of this toxic element is quite low, in soft tissues it is 0.1-2.5 and in bones 5-30 ppm of dry matter (KABATA-PENDIAS and PENDIAS 1999).(HUANG and CHEN 2001), while AYDIN (2008) reports the content of Co in the case of male lambs in Turkey on a level of 0.59-1.36mg/kg.Copper (Cu) concentration ranged from 5.30 to 10.30 mg/ kg.The highest values were found for W-Sy, while the lowest ones for W-Pl (P<0.05).Research by numerous authors (ENNE et al. 1989, SCOTT 1991, KOŁACZ et al. 1999, PATKOWSKA-SOKOŁA et al. 2003, AYDIN, 2008) prove that copper concentration in sheep wool covers a wide range from 1.70 to 25 mg/kg.RAMIREZ-PEREZ et al. (2000) report that, to a large degree, it depends on its concentration in animal diet.Low Cu level in blood can affect its diminished content in wool.
Iron (Fe) concentration varied within the range of 22.03 to 513.17 mg/kg.The highest content of this element was observed in the case of W-Sy, while the lowest in W-Pl (P<0.05).Numerous authors (WÓJCIKOWSKA and SZTYCH 1994, KOŁACZ et al. 1999, RAMIREZ-PEREZ et al. 2000, PATKOWSKA-SOKOŁA et al. 2003) report a wide range of this element concentration, from 2.56 to 52.6 mg/kg.To a large degree it depends on this element's content in soil as well as in the feed that sheep intake while grazing.Very high values in sheep wool in China (365.4-788.5 mg/kg) were reported by HUANG and CHEN (2001), and in wool from lamb in Turkey (106.07-120.52 mg/ kg) as reported by AYDIN (2008).
The observed manganese (Mn) concentration ranged from 3.37 to 22.93 mg/kg.The highest values were noted in the case of W-Sy, while the lowest ones in W-Pl (P<0.05).Some authors (GEORGIEVSKI et al. 1982, KROŚNICKA-BOMBAŁA 1996, HUANG and CHEN 2001, PATKOWSKA-SOKOŁA et al. 2003, AYDIN, 2008) report Mn content ranged from 0.35 to 20 mg/kg, depending on the state of the environment and the animal's origin.
Molybdenum (Mo) concentration ranged from 0.77 to 1.02 mg/kg.Its highest content was observed in W-Pl, while the lowest in W-Sy (P<0.05).Some authors (KOŁACZ et al. 1999, HUANG and CHEN 2001, PATKOWSKA-SOKOŁA et al. 2003) determined the molybdenum concentration at a level from 0.048 to 0.372 mg/kg.In terrestrial animal muscles this in low concentrations ranging from 0.02 to 0.05 ppm, and in bones from 0.5 to 1 ppm in dry matter.Its availability in ruminants depends on Cu/Mo ratio in feed (KABATA-PENDIAS and PENDIAS 1999).
Strontium (Sr) content ranged from 2.83 to 14.07 mg/kg.The highest content of this element was noted in the case of W-Sy, while the lowest in W-Pl (P<0.05).The authors (KOŁACZ et al. 1999, PATKOWSKA-SOKOŁA et al. 2003) report similar values of this element (8.044-9.303mg/kg) for sheep originating from different environments.Strontium accumulates mainly in hard tissues (30-100 ppm DM [dry matter]) and it takes part in Ca metabolism (PORS NIELSEN 2004).
Titanium (Ti) content ranged from 0.54 to 40.47 mg/kg.The highest values were noted for W-Sy, and the lowest ones for W-Pl.The authors (KOŁACZ et al. 1999, PATKOWSKA-SOKOŁA et al. 2003) determined Ti concentration at a level from 0.64 to 2.35 mg/kg.There is not much published literature concerning this element.It is known that titanium accumulates in animal muscles in the amount of 0.5-2.0ppm DM, and in bones at a level of 1.5 ppm DM; however, its role has not been sufficiently recognized so far (KABATA-PENDIAS and PENDIAS 1999).
Zinc (Zn) content ranged from 73.62 to 88.80 mg/ kg.The highest values were observed in the case of W-Pl, while the lowest in W-Sy (P<0.05).Authors (GEORGIEVSKI et al. 1982, ENNE et al. 1989, KOŁACZ et al. 1999, HUANG and CHEN 2001, PATKOWSKA-SOKOŁA et al. 2003, AYDIN 2008) reported a wide range of this bioelement concentration, ranged from 18.3 to 336.9 mg/kg.According to SCOTT (1991), a normal Zn content in sheep wool ranges from 35 to 195 mg/kg, depending mainly on its supply in animal diet and the physiological state of sheep.RAMIREZ-PEREZ et al. (2000) proved significant differences in this element content between the Rambouillet and Suffolk ewes' wool.

Heavy metals
Table 3 shows the results of the main heavy metals analysis.The observed arsenic (As) content was within the range of 0.206 to 0.765 mg/kg.The highest values were found in the case of W-Sy, while the lowest ones in W-Gr (P<0.05).Some authors (KOŁACZ et al. 1999, BODKOWSKI et al. 2006) report a concentration range from 0.029 to 0.23 mg/kg.That value may increase up to 1.505 mg/ kg in urbanized areas (GEBEL et al. 1996), while sheep receiving seaweed (containing arsenosugar) cumulate even 13.03μg/g of this element (7.08 on average) in fibre, and only 1.86 μg/g in lanolin (RAAB et al. 2002).Cadmium (Cd) concentration ranged from 0.134 to 0.342 mg/ kg.The highest amount of this element was found in W-Gr, while the lowest one in W-Pl (differences insignificant Some authors (ENNE et al. 1989, KOŁACZ et al. 1999, PATKOWSKA-SOKOŁA et al. 2003, AYDIN 2008) report a relatively wide range of Cd concentration, i.e. from 0.0186 to 1.8 mg/kg.Mercury (Hg) concentration ranged from 0.010 to 0.081 mg/kg.The highest amount of this element was noted in the case of W-Sy, and the lowest one in W-Pl (P<0.05).BODKOWSKI et al. (2006) observed an average concentration of Hg in the region of copper industry at the level of 0.19 ppm, GEBEL et al. (1996) reported an average Hg content in sheep wool of only 0.107 mg/kg in the area affected by mercury mines in Germany.It is known that mercury is available mainly in an organic form (KABATA-PENDIAS and PENDIAS 1999).
The results obtained from this research are difficult to interpret unequivocally.Except for K, other bioelements (Ca, P, Na, Mg and S) did significantly differ between the groups (countries).Special attention should be paid to the 5-fold higher Mg concentration in W-Sy as to compare to W-Pl.It seems that such a high variability of macroelements content in the analysed samples may be due to nutritional and biogeochemical background.Only detailed analysis of the mineral composition of soil, water and feed could provide the answer, e.g. for the reason of especially high concentration of Al, Fe, Ti or As in the wool from Syria as compared to W-Pl or W-Gr.The different values of the proportional content of the main elements, i.e.Ca/P, Na/K, Cu/Zn, Fe/Mn, Cu/Mo in particular groups (Table 4) is noteworthy.Except for S, Ca, Na and K, the order of descending values is different, and at the end of this sequence there are three heavy metals, As, Cd and Hg, in all groups (W-Sy, W-Pl and W-Gr) (Table 5).In the case of As and Hg the highest concentration in W-Sy was observed, which is also difficult to explain without a biomonitoring investigation on their habitat.Cd and Pb, however, did not differ significantly between the analysed wool samples.

Table 1
Content of marcoelements in sheep wool from Poland, Greece and Syria (mg/kg) Gehalt an Makroelementen in Schafwollen ausPolen, Griechenland und Syrien (mg/kg)

2
(KOŁACZ et al. 1999, PATKOWSKA- SOKOŁA et al. 2003), Greece and Syria (mg/ kg) Gehalt an Spurenelementen in Schafwollen (mg/kg) Cobalt (Co) content ranged from 0.65 to 2.31 mg/kg.The highest amount was in the case of W-Sy, and the lowest in W-Gr (P<0.05).The authors(KOŁACZ et al. 1999, PATKOWSKA- SOKOŁA et al. 2003)report Co range from 0.0186 to 0.1873 mg/kg, depending on the degree of environmental pollution or the country of origin.However, in the case of healthy sheep and goats in China quite low Co content values, i.e. 0.054 ppm on average, were recorded

Table 3
Content of heavy metals in sheep wool from Poland, Greece and Syria (mg/kg) Gehalt an Schwermetallen inSchafwollen (mg/kg)

Table 4
Accumulation coefficients of main chemical elements in sheep wool from Poland, Greece and Syria Kumulationskoeffizient der wichtigsten chemischen Elemente in Schafwollen Concentration of analysed elements in the wool from Poland, Greece and Syria in a descending order of values Konzentration untersuchter chemischer Elemente in Wollen in absteigender Reihenfolge der Gehaltswerte