Injeção intratesticular de solução hipertônica de cloreto de sódio como método de castração química em bovinos

• Autor(a) principal: Andrade Neto, Olmiro Adair Silveira de
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Manancial - Repositório Digital da UFSM
• Texto Completo: http://repositorio.ufsm.br/handle/1/10175
• topic: Castração química; Injeção intratesticular; Bezerros; Esterilidade; Dosagem de testosterona; Chemical castration; Intratesticular injection; Calves; Steritility; Testosterone dosage; CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA

The main objective of Brazilian cattle industry and other economic activities is to increase profitability. Reducing animal losses is important to maximize productive efficiency. In this way, castration of male calves is necessary for trading, to facilitate handling and prevent reproduction. Some methods of castration are traumatic and cause economic losses due to infection and myiasis. The objective of the present study was to evaluate the viability of an alternative method to traditional surgical castration performed under field conditions, developing a solution easy to administrate and minimally invasive. It was evaluated the effects of intratesticular injection of hypertonic sodium chloride solution (NaCL; 20%), aiming to complete castrate male calves during the first weeks of life through denaturation of testicular cells, minimizing losses caused by infections and deaths. Forty male calves were allocated into one of the experimental groups: NC (negative control) - surgically castrated immediately after birth; PC (positive control) - intact males; G1 - intratesticular injection (ITI) from 1 to 5 days after birth; G2 - ITI from 15 to 20 days after birth and G3 - ITI from 25 to 30 days after birth;. Intratesticular injection induced coagulative necrosis of Leydig cells and seminiferous tubules. Testosterone secretion and testicular development were severely impaired in animals from G1 and G2 groups (P<0.05). Rectal and scrotal temperatures were not affected by the different procedures (P>0.05) when compared to control group. Preliminary results suggest that intratesticular injection causes less discomfort to animals when compared to orchiectomy during the first weeks of life. It is concluded that intratesticular injection of NaCl hypertonic solution induces sterility and completely suppresses testosterone secretion when performed before 20 days old. The main advantages in comparison to previous studies are the fact that NaCl is atoxic, has a low cost, the technique is a safe and viable alternative to use under field conditions, avoiding the exposure of scrotal and abdominal cavities to environmental contaminants and ectoparasites.