1. Three experiments were conducted to investigate the diurnal variation of blood viscosity in broilers. In experiment 1 food and water were supplied freely at 20 degrees C (20-FW). In experiment 2 food and water were withdrawn at 20 degrees C (20-NFW), while in experiment 3 food and water withdrawn at 30 degrees C (30-NFW). 2. Blood sampling time points were 09.00 h, 15.00 h, 21.00 h, 03.00 h and 09.00 h the next day in each experiment. 3. In all experiments, whole blood viscosity (WBV), red blood cell count (RBC) and haematocrit (HCT) were greater during the dark (21.00 h and 03.00 h) than during the light period. During the dark period, there were no differences in WBV, RBC and HCT between 20-FW and 20-NFW, or between 20-NFW and 30-NFW. At 09.00 h, WBV and HCT were higher in 20-FW than in 20-NFW. At 15.00 h and 09.00 h (day 2), WBV and HCT were greater in 20-NFW than in 30-NFW. 4. There were no light-dark differences in plasma viscosity (PV), plasma protein concentration (PPC) or mean corpuscular volume (MCV) in any experiment. However, 20-NFW birds had a lower PPC and higher MCV compared with 20-FW, and a higher PPC and lower MCV compared with 30-NFW, while no difference was found in PV. 5. WBV increased linearly with RBC and HCT. PV increased with PPC, while MCV decreased. 6. These results indicate that there is diurnal variation in whole blood viscosity, which is greater during the dark than during the light period. During the light period it is strongly influenced by high environmental temperature and food and water withdrawal.

Pós-Larvas do camarão Litopenaeus vannamei, na fase de PL9-10 e PL25-26 foram aclimatadas à água doce (0,0 ‰), objetivando promover cultivos em regiões interioranas. Para isso, foram realizados dois experimentos conduzidos em aquários com capacidade útil de 44 litros e densidade de estocagem de 11,36 pós-larvas/L. No experimento 1, foram testadas diferentes concentrações de cal hidratada (0,018 g a 0,031 g) e 2 dietas, formuladas à base de ração comercial para camarão e biomassa de artêmia. No experimento 2, foram testadas 5dietas com diferentes concentrações de biomassa de artêmia (0% a 100%), inseridas em rações de peixes e camarões. No final do processo de aclimatação, a sobrevivência das póslarvas variou de 40,44% a 98,04%. Concluiu-se que pós-larvas do Litopenaeus vannamei podem ser aclimatadas à água doce e que o aumento da concentração de cal e de artêmia na ração melhoraram significativamente (p<0,05) os parâmetros zootécnicos da espécie.<br><br>Litopenaeus vannamei postlarvae with 9-10 (PL9-10), 25-26 days old (PL25-26) were acclimated to freshwater (0 ppt) for the purpose of attending the inland cultures. Two experiments were conducted in 44 liter aquariums with stocking density of 11.36 postlarvae/L. In experiment 01, different concentrations of hydrated lime (0.018 g a 0.031 g) and two diets, formulated with commercial shrimp ration and artemia biomass, were tested. In experiment 02, five diets, withdifferent concentrations of artemia biomass (0 to 100%) inserted in fish and shrimp rations, were tested. At the end of the acclimatization process, the postlarvae survival varied from40.44 to 98.04%. Results showed that Litopenaeus vannamei postlarvae can be acclimated to freshwater. Also, the increase of lime concentration and the artemia biomass in the ration improved (p<0.05) the zootechnic parameters of the species in a significant way.