Effects of chromium picolinate supplementation on growth performance, small intestine morphology and antioxidant status in ducks under heat stress conditions / Efectos de la suplementación con picolinato de cromo en el rendimiento de crecimiento, morfología del intestino delgado y estado antioxidante en patos bajo condiciones de estrés calórico

SUMMARY: The experiment was conducted to evaluate the effects of dietary supplemental chromium (Cr) on growth performance, meat quality, intestinal morphology, mucosa Hsp70 mRNA expression and antioxidant status of ducks reared under heat stress conditions. All ducks were randomly divided into three treatment groups, respectively, control group (Control, 23 ± 2 °C), heat stress group (HS, 32 ±2 °C), Cr picolinate group (CrPic, 32 ± 2 °C, 0.2 mg Cr/kg). Feed and distilled-deionized water were available ad libitum for an experimental phase of 35 days. Samples were collected on the day 14, 21 and 35 to determine biological and hematological values. Results showed that heat stress or dietary supplemental Cr both didn't have distinct influence on growth performance (P>0.05), compared to controls. Ducks fed 0.2 mg Cr/kg diet had greater ultimate pH (pHu)(P<0.05) than HS group. At day 14, the ratio of villus height to crypt depth (V/C) in CrPic group significantly increased (P<0.05) than that of HS group in jejunum. Heat stress remarkably increased Hsp70 mRNA expression in jejunum compared with controls (P<0.05). While the expression of Hsp70 mRNA in CrPic group was significantly decreased compared with HS (P<0.05). At day 21, the V/C of ileum in CrPic group significantly increased compared with HS group (P<0.05). Serum SOD levels in CrPic group were significantly higher than those in HS group (P<0.05). At day 35, Hsp70 mRNA expression and serum T-SOD levels in CrPic group significantly increased compared with controls (P<0.05). T-AOC in HS group significantly decreased compared with controls (P<0.05). Results indicate that dietary Cr supplementation doesn't influence ducks' growth performance, but has a positive effect on meat quality, small intestine morphology, also regulates Hsp70 mRNA expression under heat stress conditions, and enhances the antioxidant status.

RESUMEN: Se evaluó los efectos del cromo (Cr) dietético suplementario sobre el rendimiento del crecimiento, la calidad de la carne, la morfología intestinal, la expresión del ARNm Hsp70 en la mucosa y el estado antioxidante de los patos criados bajo condiciones de estrés por calor. Todos los patos se dividieron aleatoriamente en tres grupos: grupo control (control, 23 ± 2 °C), grupo de estrés térmico (HS, 32 ± 2 °C) y grupo de picolinato de Cr (CrPic, 32 ± 2 °C, 0,2 mg Cr / kg). El alimento y el agua desionizada destilada estuvieron disponibles ad libitum durante la fase experimental de 35 días. Las muestras se recogieron los días 14, 21 y 35 para determinar los valores biológicos y hematológicos. Los resultados mostraron que el estrés térmico o la suplementación dietética de Cr no tuvieron una influencia distinta en el rendimiento del crecimiento (P> 0,05), en comparación con los controles. Los patos alimentados con 0,2 mg de Cr / kg de dieta tuvieron un mayor pH final (pHu) (P <0,05) que el grupo HS. En el día 14, la relación de la altura de las vellosidades a la profundidad de la cripta (V / C) en el grupo CrPic aumentó significativamente (P <0,05) en relación a la del grupo de HS en el yeyuno. El estrés por calor incrementó notablemente la expresión del ARNm de Hsp70 en el yeyuno en comparación con los controles (P <0,05). Mientras que la expresión del ARNm de Hsp70 en el grupo CrPic se redujo significativamente en comparación con HS (P <0,05). En el día 21, la relación V / C del íleon en el grupo CrPic aumentó significativamente en comparación con el grupo HS (p <0,05). Los niveles séricos de SOD en el grupo CrPic fueron significativamente más altos que los del grupo HS (P <0,05). En el día 35, la expresión de ARNm de Hsp70 y los niveles séricos de T-SOD en el grupo CrPic aumentaron significativamente en comparación con los controles (P <0,05). T-AOC en el grupo HS disminuyó significativamente en comparación con los controles (P <0,05). Los resultados indican que la suplementación dietética de Cr no influye en el rendimiento de crecimiento de los patos, pero tiene un efecto positivo en la calidad de la carne, en la morfología del intestino delgado, y también regula la expresión de ARNm de Hsp70 en condiciones de estrés calórico y mejora el estado antioxidante.

Effect of pretreatment with chromium picolinate on haematological parameters during dengue virus infection in mice.

BACKGROUND & OBJECTIVE: Dengue virus (DV) has caused severe epidemics of dengue fever (DF) and dengue haemorrhagic fever (DHF) and is endemic all over India. We have earlier reported that exposure of mice to hexavalent chromium [Cr(VI)] compounds increased the severity of dengue virus infection. Trivalent chromium picolinate (CrP) is used worldwide as micronutrient and nutritional supplement. The present study was therefore, carried out to investigate the effects of CrP on various haematological parameters during DV infection of mice. METHODS: The Swiss Albino smice were inoculated with dengue virus (1000 LD50, intracerebrally) and fed with chromium picolinate (CrP) in drinking water (100 and 250 mg/l) for 24 wk. Peripheral blood leucocytes and other haematological parameters, and spleens were studied on days 4 and 8 after virus inoculations and the findings were compared with those given only CrP and the normal control age matched mice. RESULTS: CrP in drinking water for 24 wk had no significant effects on peripheral blood cells of mice. On the other hand, there was significant decrease in different haematological parameters following inoculation of normal mice with DV. In CrP fed mice the effects of DV infection were abolished on most of the haematological parameters. INTERPRETATION & CONCLUSION: The findings of present study showed that the adverse effects of DV infection, specially on platelets and leucocytes, were abrogated by pretreatment of mice with CrP. The therapeutic utility of CrP in viral infections including dengue needs to be studied in depth.