Marcadores inflamatórios e de estresse em ovinos submetidos a diferentes manejos reprodutivos

Abstract

Meeting market demands is necessary to add value to animal products. In this regard, there is an increased concern about animal health and welfare during all the production steps until slaughter, stimulating the research of feasible alternatives to avoid or minimize animal discomfort during procedures such as artificial insemination (AI), castration, dehorning, vaccination, among others. Sheep production is on the rise in Brazil, but still requires improvements in productive technologies to increase the quality of the products in several aspects. Thus, the objective of the present study was to evaluate how reproductive procedures affect animal welfare in the ovine species. Initially, we conducted a literature review about the main parameters to assess inflammation, pain and discomfort in ruminants and how these parameters are modulated by the reproductive management. Then, to evaluate a potential contraception technique, 11 lambs were allocated in two groups to investigate the feasibility and the impact of intratesticular injection (ITI) of a solution containing NaCl combined with anesthetic and analgesic compared to control (non-castrated) animals. No significant effects of procedure were observed on red blood cells (hematocrit and number of red blood cells), total plasma protein levels, cortisol levels and leucogram (number of white blood cells, lymphocytes, segmented neutrophils and neutrophil-to-lymphocyte ratio). Increased fibrinogen levels were observed in animals from ITI group on D3 after procedure. No significant differences in daily weight gain were observed. Clinical evaluation of the lambs from ITI group revealed that only one (out of 8) testicle regressed, whereas in the histological evaluation it was observed that ITI induced only focal inflammation, alterations in basement membrane integrity and necrosis. In conclusion, the assessment of several markers of inflammation, pain and stress should be considered to provide consistent results on the effect of different procedures on the welfare of ruminants. Furthermore, ITI was not efficient in inducing contraception in lambs, despite focal alterations were observed in testicular histological sections. The potential contraceptive method did not significantly alter most of the blood parameters evaluated.