Chemical castration in cattle with intratesticular injection of sodium chloride: Effects on stress and inflammatory markers

摘要

Intratesticular injection (ITI) of sodium chloride (NaCl) is efficient for chemical castration of young calves, but its effects on calves welfare are unknown. Two experiments were conducted to evaluate the effects of ITI of 20% NaCl on stress and inflammatory markers in calves less than 20 days old and to assess the efficiency of ITI of 30% NaCI in 5 months old calves. In Experiment 1, control calves were only restrained and compared to calves submitted to castration through surgery (SC) and III with 20% NaCI (n = 9/group). No differences were observed for the eye corner temperature measured by thermography from 60 s before to 60 s after the procedures (P > 0.05). In the SC group, acute serum cortisol levels increased at 30 and 60 min after the procedure, but increased levels in the ITI group occurred only at 30 min (P 0.05). Chronic discomfort markers were measured at 0, 24, 48, 72 and 96 h after the procedures (DO, D1, D2, D3 and D4, respectively). The serum levels of the paraoxonase 1 (PON1) enzyme and cortisol did not differ among groups (P > 0.05). Scrotal temperature was higher at D1 in the SC group than for the other groups, but lowest at D4 compared to the control (both P 0.05). In Experiment 2, histological sections of testes were compared after ITI with either 30% NaCI or 30% calcium chloride (CaCl2), to intact calves (control). After 60 days, intact seminiferous tubules and mediastinum were observed after ITI with 30% NaCI, whereas coagulative necrosis, inflammatory infiltration and calcification occurred after ITI with 30% CaC12. Efficient chemical castration through IT! of 20% NaCI in young calves was followed by slight stress and inflammatory responses compared to surgical castration. However, ITI of 30% NaCI was ineffective for chemical castration of 5 months old calves. (C) 2016 Elsevier Inc. All rights reserved.