Implications of low fiber levels in finishing lambs on performance, health, rumen, and carcass parameters.

The objective of this study was to evaluate the effects of different levels of NDF in high-concentrate diets on performance and aspects ruminal, blood, and carcass parameters of finishing lambs. Twenty-four lambs, with initial BW of 24 ± 3 kg, were randomly divided into individual pens, in a completely randomized design, comprising three treatments with eight repetitions each. The treatments consisted of dietary levels of 15%, 20%, and 25% of NDF, based on DM. The diets were composed of corn, soybean meal, minerals, and corn silage and were offered twice a day, with daily control of what was offered and refused, to determine dry matter intake (DMI). The animals were weighed weekly and slaughtered after 50 days of confinement. Performance evaluations, blood parameters, carcass, and ruminal parameters were evaluated. Lambs fed with lower dietary fiber had better carcass yield (P < 0.005). Blood count, blood biochemical parameters, rumen short-chain fatty acid production and protozoan population were not affected by the dietary NDF level. It was concluded that in high-concentrate diets with 15% NDF resulting in better weight gain of the animals in the confinement, good carcass yields without the animal having altered health and ruminal parameters.

Subchronic toxicity evaluation of a treated urban sewage sludge.

Disposal of tons of sludge produced daily by sewage treatment plants in large cities is a serious problem. Because recycling and application in agriculture have been proposed, the Brazilian National Environmental Council (CONAMA, 2006) issued a legal norm that regulates the use of the sewage sludge (SS) in crops. Due to the complex chemical nature of such products, characterization by analytical methods for health and environmental risk assessment has severe limitations. To overcome such limitations, it is necessary to (1) assess the toxicological potential of SS and (2) identify possible adverse effects in vivo in order to provide critical information for future environmental regulations. The present study was conducted to determine the potential toxicity of SS obtained from a representative urban treatment plant located in the Sao Paulo State, Brazil. Male and female Wistar rats were fed ad libitum a pelleted diet containing varying amounts of SS. No relevant clinical, hematological, urinary, or gross organ morphological alterations were observed in both genders of rats orally exposed to SS at up to 3.8 g/kg/d for 90 d. Sewage slude produced increased incidence of centrilobular hepatocyte hyperplasia at the high dose and significantly increased aspartate aminotransferease (AST) activities at all doses in both genders. Although the present data indicate some liver involvement, these alterations were considered adaptative and not toxicologically relevant, as the responses were relatively mild, not dose dependent, and no other parameters were markedly affected. The present results may contribute to the establishment of protocols for potential usage in SS agricultural soil application.