RESUMO
Toxicants on fish may induce genetic alterations that can be used as genotoxic markers. We evaluated DNA damage using alkaline comet assay applied on erythrocytes after in vivo exposure of Prochilodus lineatus to different concentrations of Cypermethrin (0.300, 0.150, 0.075 and 0.000 microg/L) as a probable chemical mutagen. The results revealed a significantly higher level of DNA damage at all concentrations of Cypermethrin tested compared to control and background level (p < 0.05). We have standardized the technique for one of the most common native fish species that will be useful for biomonitoring genotoxicity in polluted waters of the region.
Assuntos
Ensaio Cometa/métodos , Peixes/genética , Inseticidas/toxicidade , Piretrinas/toxicidade , Poluentes Químicos da Água/toxicidade , Álcalis , Animais , Dano ao DNA , Monitoramento AmbientalRESUMO
The experiment tested the hypothesis that short-term feeding of barley just before lambing would be as effective as maize in stimulating early production of colostrum. Both grains are high in starch, and should provide a substrate for lactose which, in turn, promotes lactogenesis. Thirty-five Corriedale ewes bearing single foetuses and 25 bearing twin-foetuses from a synchronised mating were fed on pasture during most of gestation. Fourteen days before the expected time of lambing the single- and twin-bearing ewes were allocated to three treatments and fed (1) a basal diet of lucerne hay to meet their nutrient requirements, (2) the basal diet plus a supplement of whole barley; or (3) the basal diet plus a supplement of cracked maize. The twin-bearing control ewes accumulated more colostrum than the single-bearing control ewes at birth (292 v. 190 g). However, supplementation with barley or maize increased the colostrum at birth to 360 and 541 g in singles and 648 and 623 g in twins. We conclude that barley is a good alternative to maize to stimulate production of colostrum especially in twin-bearing ewes whose lambs are the most likely to benefit from the supplement.