VETERINARSKI ARHIV 69 (6), 349-355, 1999

ISSN 1331-8055 Published in Croatia

Lead concentration in mineral salt mixtures used in beef cattle food supplementation in Brazil

Wilmar Sachetin Marçal¹*, Laurenil Gaste¹, Márcio Liboni¹, Paulo Eduardo Pardo², Marcos Roberto Do Nascimento³, and Cesar Souza Hisasi¹

¹Londrina State University, Londrina, Paraná, Brazil

²São Paulo Western University, Presidente Prudente, São Paulo, Brazil

³National Center of Nuclear Energy, Poços de Caldas, Minas Gerais, Brazil

* Contact address:
Prof. Dr. Wilmar Sachetin Marçal,
Department of Veterinary Clinic, Londrina State University; CP nº 6001, Londrina - Parana, Brazil, CEP: 86051-970;
Phone 55 43 371 4717; Fax 55 43 371 4063; E-mail: wilmar@uel.br

Marçal, W. S., L. Gaste, M. Liboni, P. E. Pardo, M. R. D. Nascimento, C. S. Hisasi: Lead concentration in mineral salt mixtures used in beef cattle food supplementation in Brazil. Vet. arhiv 69, 349-355, 1999.

ABSTRACT

We measured lead concentrations in some salt formulations collected from the states of Mato Grosso and Mato Grosso do Sul, in Brazil. Lead concentration was determined by spectrophotometric technique of atomic plasma induction. Of the 30 analysed samples, 12 had values above 30 ppm, the maximum concentration recommended by the National Research Council (1980). Lead concentrations varied from 1.6 and 460.0 ppm, the highest result found in a sample from Mato Grosso do Sul State, which has the largest bovine herd in Brazil. These results show the necessity for monitoring in the industry, due to the fact that some mineral mixtures can be dangerous, resulting in bovine toxicity.

Key words: mineral salt, lead, cattle, Brazil

Introduction

The increasing commercialisation of mineral salt mixtures for animal ingestion in Brazil is the main reason why the mixture industry has to reduce costs, with the aim of winning a market and thereby guaranteeing its future business. Even with the concept of total quality, some aspects have been relegated to second place, such as the sources of raw materials that comprise mineral salt mixtures, in order that they are chosen at the most accessible price, exclusive of imports.

This facet has become a concern among nutritionists, clinical veterinarians and technicians oriented towards health and animal production, because it is believed that some new mineral formulations can be contaminated by toxic elements, above all by heavy metals and radioactive substances. For that reason, an investigation research project was launched to evaluate the level of pollutants in mineral formulations used in Brazilian cattle feed supplement. Based on certain information received from the National Agriculture Department there are currently approximately 5,500 different mineral mixtures being sold throughout the Brazilian national market.

Accordingly, the aim of the present research is to investigate the xenobiotic presence in some different mineral supplements produced in Brazil, employing laboratory analysis to quantify those pollutants that can be connected with the macro and micro mineral elements of the formulations prepared for animal feed.

The first element chosen for investigative study was lead, considered by many specialists to be an inorganic element of greater risk to animal husbandry, particularly in the bovine species (ANONYMOUS, 1980a; KANEKO, 1989; VILLEGAS-NAVARRO et al., 1993; MARÇAL and TRUNKL, 1994), its transmission to animals being possible through the ingestion of contaminated mineral formulations.

Material and methods

Small portions of the same form of mineral salt were collected at each of the selected rural properties, forming a "pool" of a representative sample, amounting to approximately 200 grams of the stock of mineral salt maintained at the farm. The samples were conditioned in transparent plastic containers, previously identified and which were then analysed at the National Commission of Nuclear Energy (CNEN) Laboratory of Poços de Caldas, Minas Gerais, Brazil.

The analytic methodology used for lead determination in the mineral salt was that the samples were dried previously to 110 °C for approximately two hours. The solubilization made by nitric acid was that the lead was separated from the sample for extraction with pyrrolidine ammonia ditiocarbonate (APDC) p. a. in pH 2.3±0.1.

Determination was executed by spectrometry of atomic emission by induction plasma coupled in 220.3 nm, using a JARREL-ASH, model 975 spectrometer.

Analysis methodology was made based on CLESCERI et al. (1975) and in ANONYMOUS (1980). Limit of determination of the method is 0.05 ppm.

To calculate the values of central tendency (average and medium), percentage for the quantitative variables and variability values (deviate pattern and variation coefficient), the program SAS/BASIC was used, as described in SAS Procedures Guide (ANONYMOUS, 1990).

Results

The results obtained from the present research, whose inorganic lead element was quantified in 30 mineral formulations produced in the two states, are presented in Table 1 and Fig. 1.

Table 1. Lead concentrations in individual samples of mineral salt in Brazil

Fig. 1. Average values (N=30) for lead concentrations in mineral salt from two states in Brazil, correlated with reference values from MALETTO (1986) and ANONYMOUS (1980)

Discussion

Concern about mineral formulations contaminated by metallic elements and/or radioactive substances has been a preoccupation for technicians and farmers, generating debates among researchers in several countries around the world, gaining more followers in the early nineties.

The subject of sanitary control in animal feeding has been developing greatly in Brazil also, and it seems to be increasingly strengthened by specialists' participation in practical objectives.

In that respect, the main proposal in this study is to investigate the lead element presence in mineral, mixed supplements produced in Brazil. Up until now, there has been no research of this kind anywhere in the country.

Taking into account the high number of mineral formulations on the market in this country, we proceeded to select samples in only some of the manufacturing states. One approach is work in some federation states holding a significant number of bovines in its effective animal population. The states chosen were Mato Grosso and Mato Grosso do Sul, which together hold approximately 30% of the bovine herds in Brazil.

Based on this important aspect, the ease of contact with our collaborators in those selected states provided us with the necessary confidence to commence and conclude the tasks, since the previous rise in both states demonstrated that there were more than fifteen different marks in each mineral mixture.

In several samples, the values extrapolate the acceptable maximum limit of 10 ppm attributed by MALETTO (1986) and the maximum value of 30 ppm attributed by ANONYMOUS (1980a), as well as for the Association of American Feed Control Officials Incorporated (ANONYMOUS, 1993).

In the analytic detection of lead in the mineral formulations, it was not possible to separate the raw material components, so in order to proceed with the investigation the authors worked with readily industrialized formulations.

The greater suspicion is that lead presence in the mineral mixture is traceable to phosphorus sources, where these represent the highest cost in the mineral salt composition (SOUSA, 1981; ROSA, 1989), thereby inducing industries to find it in cheaper, alternatives sources.

The connotation of lead being connected with sources of phosphate can be exemplified by the natural rock, phosphatus (AMMERMAN et al., 1977; VIANA, 1985; ROSA, 1989; CAMPOS NETO, 1992) or with foreign phosphoric acid (BRITO, 1993). It is extremely important to remember that xenobiotics can originate from raw materials of micro elements (CAMPOS NETO, 1992; CAMPOS NETO and MARÇAL, 1996).

It is necessary to emphasise that the purpose of the next stage in this work will be to investigate the sub-clinical aspects in bovines which have consumed mineral salt with toxicant considered levels, since bovine saturnism toxicity clinical symptoms are known classically, and this hypothesis indicates that such research would be of no interest. The main aim is to verify changes in the bovine reproductive system, investigating possible interferences in the reproductive cycles of cows and changes in performance, as referred to by STUART and OEHME (1982) and McDOWELL (1985).

This seems to be an opportune and important moment for such a cause, as today, at the beginning of the third millennium, Brazil has one of the largest commercial bovine herds anywhere in the world, as highlighted by MARTIN (1993). The country is still developing its conquests of new horizons, attempting to increase its bovine population of 154,440,803 (ANON, 1994) and keen to expand its business with partners in the South American Economic Community.

Conclusions

Analysis of results observed in researches conducted to date permits the following conclusions:

1^st) sixteen of the thirty analysed samples presented results below 10 ppm, considered the maximum limit for MALLETO (1986), representing 53.3% of the analysed mineral supplements;

2^nd) in the range of 10 to 30 ppm, two samples were detected, which represents 6.7% of the analysed samples;

3^rd) twelve samples were found with a lead concentration above 30 ppm, the maximum limit attributed by NATIONAL RESEARCH COUNCIL (ANON, 1980a), representing 40% of the analysed mineral formulations;

4^th) the largest value found, 460 ppm, refers to a mineral formulation sold in the state of Mato Grosso do Sul, which has the largest bovine herd in Brazil.

Reference

ALLEN, J. D. (1992): Minerals in animal feed. Industrial Minerals 292, 35-39.

AMMERMAN, C. B., S. M. MILLER, K. R. FICK, S. L. HANSARD (1977): Contaminating elements in mineral supplements and their potential toxicity: a review. J. Ani. Sci. 44, 485-508.

ANDRIGUETO, J. M., L. PERLY, I. MINARDI, A. GEMAEL, J. S. FLEMMING, G. A. SOUZA, A. BONA FILHO (1990): Os princípios nutritivos e suas finalidades. In: Nutrição Animal. 4a. ed. Nobel. São Paulo. pp. 189-255.

ANONYMOUS (1980): Annual book of ASTM Standards. American society for testing and materials. Water. Philadelphia. pp. 450-464.

ANONYMOUS (1980): Mineral tolerance of domestic animals. National Research Council. Subcommitte on Mineral Toxicity in Animals. National Academy of Science. Washington D. C. pp. 256-76.

ANONYMOUS (1990): SAS procedures guide: version 6. 3^rd ed cary, SAS Institute. p. 705.

ANONYMOUS (1993): Official guidelines for contaminant levels permited in mineral feed ingredients. Association of american feed control officials incorporated. Indiana. 19. 172-176.

ANONYMOUS (1994): Anuário estatístico do Brasil. IBGE. Efetivo pecuário, Rio de Janeiro 54, 3-62.

BRITO, J. de (1993): Fosfato bicálcio feed grade. Cajati. Serrana 17. Apostila.

CAMPOS NETO, O. (1992): Pesquisa esclarece dúvidas sobre déficit na nutrição animal. O Corte, São Paulo 24, 14.

CAMPOS NETO, O., W. S. MARÇAL (1996): Os fosfatos na nutrição mineral de ruminantes. Rev. Criad., São Paulo 793, 8-10.

CLESCERI, L. S., A. E. GREENBERG, R. R. TRUSSELL (Eds) (1975): Standard methods for the examination of water and wastewater. Washington. APHA 151-152.

MALETTO, S. (1986): Correlação da nutrição mineral e a sanidade. Seminário sobre nutrição mineral, São Paulo. Anais. São Paulo. p. 38.

MARÇAL, W. S., TRUNKL, I. (1994): Poluição industrial na zona rural: implicações na saúde pública. Congresso brasileiro de medicina veterinária, ed. 23. Olinda. p. 656.

MARTIN, L. C. T. (1993): Nutrição mineral de bovinos de corte, 2^nd ed. Nobel. São Paulo. p. 173.

McDOWELL, L. R. (1985): Nutrition of grazing ruminants in warm climates. Academic Press. Orlando. pp. 182-186.

ROSA, I. V. (1989): Fosfato natural como suplemento de fósforo para bovinos. In: Coletânia de seminários técnicos 1986/88 (Valle, E. R., M. R. Soares, M. A. M. Schenck, Eds.). Campo Grande. Embrapa. 59.

ROSA, I. V., J. L. A. CARDOSO (1987): Fósforo, fosfato de rocha e fluorose em bovinos. Campo Grande. Embrapa 33. Boletim de pesquisa 4.

SOUSA, J. C. (1981): Aspectos da suplementação mineral de bovinos de corte. Circ. Téc., cent. Nac. Pesqui. Gado Corte 5, 1-50.

STUART, L. D., F. V. OEHME (1982): Environmental factors bovine and porcine abortion. Vet. Hum. Toxicol. 24, 435-41.

VIANA, J. A. C. (1985): Fontes de sais minerais para bovinos e o desafio de suplementos de fósforo no Brasil. Simpósio sobre nutrição de bovinos 3. Piracicaba. Anais Piracicaba. FEALQ.

VILLEGAS-NAVARRO, O. D. M. ELENA BUSTOS, A. REYES RAYMOND, T. A. DIECK, J. L. REYES (1993): Determination of lead in paired samples of blood and synovial fluid of bovines. Exp. Toxicol. Pathol. 45, 47-49.

Received: 23 August 1999
Accepted: 15 Decembar 1999

Marçal, W. S., L. Gaste, M. Liboni, P. E. Pardo, M. R. D. Nascimento, C. S. Hisasi: Koncentracija olova u mjesavinama mineralnih soli koje se dodaju u hranu goveda u Brazilu. Vet. arhiv 69, 349-355, 1999.

SAZETAK

Mjerena je koncentracija olova u nekim mineralnim pripravcima koji se dodaju u hranu goveda u saveznim drzavama Mato Grosso i Mato Grosso do Sul u Brazilu. Koncentracija olova je odredivana spektrofotometrijskom metodom atomske plazmalne indukcije. Od 30 pretrazenih uzoraka, 12 je sadrzavalo vise od 30 ppm olova, sto je najveca dozvoljena koncentracija koju preporucuje National Research Council (1980). Koncentracija olova kretala se od 1,6 do 460,0 ppm, a najvisa koncentracija je nadena u uzorku mjesavine mineralnih dodataka za hranu goveda iz savezne drzave Mato Grosso do Sul, koja ima najveci broj goveda u Brazilu. Ti rezultati upozoruju na prijeku potrebu kontole u industriji, jer je utvrdeno da neke mineralne mjesavine mogu biti vrlo otrovne za goveda.

Kljucne rijeci: mineralne soli, olovo, govedo, Brazil