Effects of crude protein and lactose levels in diets on growth performance, intestinal morphology, and expression of genes related to intestinal integrity and immune system in weaned piglets.

To evaluate the effects of crude protein (CP) and lactose (LAC) for weaned piglets on performance, intestinal morphology, and expression of genes related to intestinal integrity and immune system, 144 piglets with initial weight 7.17 ± 0.97 kg were allotted in a randomized design, in a 2 × 3 factorial arrangement (20.0% and 24.0% CP and 8.0%, 12.0%, and 16.0% LAC) with eight replicates. Piglets fed 20.0% CP had greater weight gain and feed intake. Including 12.0% LAC in the 20.0% CP diet provided higher villous height in the duodenum than 8.0% LAC, and 12.0% or 16.0% LAC in the 24.0% CP diet resulted in higher villous height in the jejunum and ileum, and higher villi/crypt ratio in the ileum than 8.0% LAC. No effects of CP and LAC on interleukin-1ß and tumor necrosis factor-α mRNA were observed. The 16.0% LAC diet provided higher gene expression of transforming-ß1 growth factor. Feeding 20.0% CP resulted in better performance than 24.0% CP. The 12.0% LAC diet promoted greater genetic expression of occludin and zonula occludens. Including 12.0% LAC in the diet may improve intestinal epithelial morphology and integrity, and these improvements are more evident when piglets are fed diets with 24.0% CP.

Freshwater parameters in the state of Rio Grande do Sul, southern Brazil, and their influence on fish distribution and aquaculture

This study analyzed the relationship between several water quality parameters (pH, hardness, alkalinity, turbidity, iron and manganese) levels measured over a 16 year period with fish distribution and aquaculture in the state of Rio Grande do Sul, Southern Brazil. The mean pH values were within a neutral range (6.5-7.5), but the maximum and minimum values reached inappropriate levels for fish farming in some cities. Alkalinity levels were very low (except in the southwest region of the state), which may have contributed to pH variation. Hardness, turbidity, iron (except the region near Caçapava do Sul City) and manganese were within safe ranges for fish farming; however, turbidity levels occasionally increased to levels outside the safe range. In conclusion, the water quality in the Rio Grande do Sul, in general, can be considered adequate for aquaculture, but the fish farmers must be aware of the methods to reduce turbidity, such as the use of calcium sulfate.(AU)

Este estudo analisou a relação entre vários parâmetros de qualidade da água (pH, dureza, alcalinidade, turbidez, ferro e manganês durante 16 anos) com a distribuição de peixes e piscicultura no estado do Rio Grande do Sul, Brasil. O pH ficou em média em uma faixa neutra (6,5-7,5), mas valores máximos e mínimos atingiram níveis não apropriados para a piscicultura em algumas cidades. Os valores de alcalinidade foram baixos (exceto na região sudoeste do estado), o que poderia contribuir para oscilações no pH. Dureza, turbidez, ferro (exceto na região próxima à cidade de Caçapava do Sul) e manganês ficaram dentro de níveis aceitáveis para a piscicultura, mas a turbidez ocasionalmente elevou-se a níveis fora dessa faixa aceitável e os piscicultores devem ter algum mecanismo para reduzi-los. Em conclusão, de forma geral a qualidade da água do Rio Grande do Sul pode ser considerada adequada para a aquicultura, mas os piscicultores devem conhecer métodos para corrigir a turbidez, como a utilização de sulfato de cálcio.(AU)