Effects of 25-hydroxycholecalciferol with two D3 vitamin levels on production and immunity parameters in broiler chickens.

This study was performed in Ross 308 chickens aged 1-21 days and aimed to evaluate whether the addition of 25-hydroxycholecalciferol (25(OH)D3 ) to broiler chicken diets affects their growth performance and immunity. A completely random 2 × 2 factorial arrangement was used with two levels of vitamin D3 and the absence or presence of 25(OH)D3 , corresponding to four treatments based on sorghum + soya bean diets: (i) 200 IU of vitamin D3 /kg of feed (Diet 1) (NRC, ), (ii) Diet 1 + 69 µg of 25(OH)D3 /kg of feed (Diet 2), (iii) 5,000 IU of vitamin D3 /kg of feed (Diet 3) and (iv) Diet 3 + 69 µg of 25(OH)D3 /kg of feed (Diet 4). Each treatment was conducted with six replicates of 10 chickens each. Water and feed was supplied ad libitum. The results showed significantly increased growth and tibia ash (p < .05) in the birds fed 5,000, IU of vitamin D3 /kg + 25(OH)D3 . Additionally, the cellular immune response increased significantly (p < .05) in both treatments with added 25(OH)D3. Based on the results obtained under the current test conditions, the addition of 25(OH)D3 at a rate of 69 µg/kg to diets containing vitamin D3 improved the cellular immune response and mineral deposition in the bones of broilers aged 1-21 days. Because these parameters are very important in modern poultry farming, these results indicate that supplementation with 25(OH)D3 should improve broiler production.

Interrupted resistance training and BMD in growing rats.

A resistance training program, where the exercise was uninterrupted (UT, i.e. continuous repetitions) was compared against another resistance training program where the exercise was interrupted (IT, i.e. 2 exercise sessions during a training day) for enhancing bone modeling and bone mineral density (BMD) in maturating animals. The total volume of work performed between the two resistance training programs was equivalent by design. Young male rats (approximately 8 weeks old) were randomly divided into Control (Con, n=8), UT (n=8) and IT (n=7) resistance trained groups. The UT and IT groups were conditioned to climb a vertical ladder with weights appended to their tail 3 days/week for 6 weeks. After the 6 week training regimen (Mean+/-SD), tibial BMD (assessed via DXA) was significantly greater for UT (0.237+/-0.008 g/cm(2)) and IT (0.238+/-0.005 g/cm(2)) compared to Con (0.223+/-0.004 g/cm(2)). Further, serum osteocalcin (OC) was significantly greater for UT (45.65+/-2.83 ng/ml) and IT (46.33+/-4.60 ng/ml) compared to Con (37.86+/-4.04 ng/ml). There was no significant difference in BMD or serum OC between UT and IT groups. The results indicate that both resistance training programs were equally effective in elevating BMD in growing animals.

Interrupted vs. uninterrupted training on BMD during growth.

This study compared a resistance training program where the exercise was uninterrupted (UT, i.e., continuous repetitions) against a resistance training program where the exercise was interrupted (IT, i.e., 3 exercise sessions during a training day) for enhancing bone modeling and bone mineral density (BMD) in maturating animals. The total volume of work performed between the two resistance training programs was equivalent by design. 24 young male rats were randomly divided into Control (Con, n = 8), UT (n = 8) and IT (n = 8) resistance trained groups. The UT and IT groups were conditioned to climb a vertical ladder with weights appended to their tail 3 days/wk for 6 wks. After the 6-wk program, serum osteocalcin was not significantly different between groups, whereas the adjusted urinary deoxypyridinoline (DPD) was significantly lower for both UT (81.03 +/- 5.53) and IT (88.30 +/- 7.29) compared to Con (128.13 +/- 9.99). Tibial BMD (assessed via DXA) was significantly greater for UT (0.222 +/- 0.005 g/cm (2)) and IT (0.219 +/- 0.003 g/cm (2)) when compared to Con (0.205 +/- 0.004 g/cm (2)). There was no significant difference in DPD or BMD between UT and IT groups. The results indicate that both interrupted and continuous, uninterrupted resistance training programs were equally effective in stimulating bone modeling.