Comparative studies of cadmium-induced single strand breaks in female and male rats and the ameliorative effect of selenium.

Cadmium (Cd2+) is an environmental pollutant. In humans and animals it has no known biological benefit, but rather has genotoxic and carcinogenic effects. Comparative studies of cadmium-induced DNA single strand breaks in kidney and liver cells of female and male Harlan Sprague-Dawley rats were conducted, and the role of selenium in mitigating cadmium toxicity in male and female rats was also evaluated. Analysis of the results showed differences in organ and sex susceptibility to cadmium-induced DNA damage. There were more single strand breaks in DNA from liver and kidney cells of male rats than in those of the females. Concurrent administration of selenium with cadmium significantly (P<0.001) reduced DNA damage in male rats more than in female rats. However, administration of selenium alone induced DNA strand breaks in female rats at a rate which was significantly greater (P<0.001) than in male rats. These findings demonstrate differences in sex susceptibility to cadmium, and some variance in the ameliorative effects of selenium in male and female rats.

Digestibility, nitrogen utilization, and voluntary intake of ensiled crab waste-wheat straw mixtures fed to sheep.

Crab waste and wheat (Triticum aestivum L.) straw mixtures, ensiled with different additives, were evaluated in metabolism and palatability trials. Crab waste and straw were mixed in proportions of 1:1, wet basis, with 20% water and different additives, and ensiled in 210-L metal drums double-lined with polyethylene bags. Thirty crossbred wethers (40 kg initial BW) were fed a 1) basal diet consisting of 75% orchardgrass (Dactylis glomerata L.) hay and 25% concentrate, 2) ensiled crab waste-wheat straw, with 16% (vol/wt) added glacial acetic acid, 3) crab waste-wheat straw ensiled with 20% dry molasses, 4) crab waste-wheat straw ensiled with 20% dry molasses and a microbial inoculant, and 5) ensiled wheat straw supplemented with urea. Apparent digestibility of DM and CP was lower (P < .05) for acetic acid-treated silages than for silages containing molasses. Nitrogen retention was higher (P < .05) for molasses-inoculant-treated silage than for the molasses-treated silage (5.4 vs 3.9 g/d). Ruminal NH3 N and blood urea N were higher (P < .05) for lambs fed the molasses-treated silages than for those receiving the acetic acid-treated crab waste mixture. Among the wethers fed crab waste silages, intake was lower (P < .01) for wethers receiving the acetic acid-treated silage than for those fed the molasses-treated mixtures. Treatment of crab waste-straw mixtures with molasses produced a palatable silage that was efficiently utilized by wethers.