Qualidade extrínseca de peles de caprinos e ovinos abatidos no município de São Luís - MA: proposição de um modelo de avaliação técnica e operacional fundamentado em defeitos na perspectiva do desenvolvimento local

Abstract

The low extrinsic quality of goat and sheep skins available in Brazil has limited the more expressive performance of the leather sector, hampering the country's ability to add value to the product. Therefore, quality must be addressed comprehensively, with procedures that ensure progressive gains in the production chain, from rural producers to industrial entrepreneurs. In this context, the objective of this study was to propose a technical and operational evaluation model based on defects to determine the extrinsic quality of goat and sheep skins slaughtered in the municipality of São Luís, MA, and to promote local development. To this end, the study was divided into three stages: (i) bibliographic survey on the subject under study; (ii) evaluation of goat and sheep skins slaughtered in the municipality of São Luís, state of Maranhão. In this stage of the study, whole skins were randomly selected and the assessment was carried out on site, after the skinning stage, with the evaluation of the dorsal lateral region of the skins, neck and belly. The defects considered in the study were: ticks; botfly; open scratch; healed scratch; hot iron brand; photosensitization; dermatitis; and holes. The length, area, mass and thickness of the skins were also evaluated; and, (iii) development of a technical and operational evaluation model based on defects visible to the naked eye, organized into the following topics: objective, reference documents, glossary, definitions, field of application, responsibilities and description. At this stage, a guide was also prepared for rural producers with important points for improving the quality of small ruminant skins. As a result, 116 goat skins and 31 sheep skins were evaluated, totaling 147 skins, in which it was found that the goat and sheep skins were classified in the categories small (7.1 to 8 dm) and very small (21 to 27 dm2) for the parameters length and area, respectively. Regarding mass, goat skins were classified in the light category (1.3 to 2.0 kg) and sheep skins in the very light category (0.9 to 1.2 kg), for natural skins. Regarding thickness, sheep skins ranged from 1 to 3 mm and goat skins from 1 to 2 mm. The majority of skins classified as “A” were in the study (n = 109; 74.15%); 38 skins (25.85%) were classified in class B, and in this category ticks on the belly and healed scratch outside the lateral dorsum region were evidenced. Considering in decreasing order the frequency of defects capable of discriminating skins in categories “A” and “B”, the following are cited: open scratch (25.85%), presence of ticks (5.44%), healed scratch (2.72%) and hot iron mark (2.72%). The skins of caprinas and sheep are of good extrinsic quality, and can be classified into categories according to length, area and mass, according to international regulatory frameworks, national scientific publications and requirements of Brazilian tanneries. Although present in small quantities, ectoparasites, open and healed scratches and hot iron marks can negatively affect the quality of the skins of both species if preventive management measures are not implemented on rural properties and in slaughterhouses. The proposed technical and operational model is simple to implement and concatenated with the local reality of Maranhão, allows the segregation of skins into classes (A, B, C, D and E) and represents an initial milestone towards better remuneration for rural producers, with market gains and promotion of local development. The guide aims to bring knowledge on the subject to rural producers as a way of valuing goat and sheep skin, and also to highlight the role of postgraduate studies in producing knowledge both intra and extra muros