Two experiments were conducted to evaluate the effect of formaldehyde vaporization of a hatcher on the tracheal epithelium of chick embryos, and on the production performance and behaviour of commercial broiler chicks. In experiment 1, chick embryos were exposed to 23.5 ppm of formaldehyde vapour during the last 3 days of incubation. Tracheal samples were taken at 0, 6, 30 and 54 h after exposure to formaldehyde and examined by scanning electron microscopy for pathological changes. Observable lesions included excessive accumulation of mucus, matted cilia, loss of cilia and sloughing of the epithelium. The lesions were more severe in chicks exposed for 54 h as compared to those exposed for 6 or 30 h. In experiment 2, 60 chicks that had been exposed to formaldehyde vapour as above and 60 control chicks were used to investigate the effect of formaldehyde fumigation on production performance and behaviour. Formaldehyde vaporization resulted in higher weekly (days 0-6 and 21-27) and total (days 0-41) feed intake and poorer weekly (days 0-6, 7-13, 21-27 and 28-34) and overall (days 0-41) feed conversion ratios. Body weight, mortality and behaviour (eating, drinking, sitting and standing activities) were not affected by formaldehyde fumigation.
Mucuna pruriens has been used by native Nigerians as a prophylactic for snakebite. The protective effects of M. pruriens seed extract (MPE) were investigated against the pharmacological actions of N. sputatrix (Javan spitting cobra) venom in rats. The results showed that MPE-pretreatment protected against cardiorespiratory and, to a lesser extent, neuromuscular depressant effects of N. sputatrix venom. These may be explained at least in part by the neutralisation of the cobra venom toxins by anti-MPE antibodies elicited by the MPE pretreatment.
The protective effects of Mucuna pruriens seed extract (MPE) against the cardio-respiratory depressant and neuromuscular paralytic effects induced by injection of Calloselasma rhodostoma (Malayan pit viper) venom in anaesthetized rats were investigated. While MPE pretreatment did not reverse the inhibitory effect of the venom on the gastrocnemius muscle excitability, it significantly attenuated the venom-induced cardio-respiratory depressant effects (p < 0.05). The protection effects may have an immunological mechanism, as indicated by the presence of several proteins in the venom that are immunoreactive against anti-MPE. However, we cannot rule out the possibility that the pretreatment may exert a direct, non-immunological protective action against the venom.