Dietary mannitol increased the absorption of calcium and magnesium in rats

The effect of mannitol on bone‐related mineral absorption and retention and the mechanism was investigated in this study. Fourteen 8‐week‐old male Wistar rats in experiment 1 and same number and age cecectomized Wistar male rats in experiment 2 were divided into two subgroups of seven animals, respectively, fed diets containing 0 or 4% mannitol for 28 days. Mineral balance tests were determined twice during days 8–12 and days 22–26, and the rats were slaughtered on day 28 both in experiment 1 and experiment 2. The whole caecum and colon were collected with the content to analyse tissue weight, content weight, content's pH and moisture, organic acids' concentration and mineral levels. In experiment 1, Ca absorption and retention and Mg absorption were significantly increased by mannitol feeding during days 8–12. Caecal total weight, tissue weight and content weight were increased, the pH of caecum and colon was reduced, and the concentrations of caecal short‐chain fatty acids (SCFAs) were modified by mannitol feeding. In experiment 2, during days 8–12 and days 22–26, Ca absorption and retention were significantly lowered by mannitol feeding in cecectomized rats; however, mannitol feeding decreased Mg absorption during days 8–12, but did not impact Mg retention. Colonic total weight, tissue weight and content weight were significantly increased, and colonic pH was reduced by mannitol feeding. In conclusion, dietary mannitol increased the absorption of Ca and Mg and the caecum markedly contributed to this promoting effect of mannitol.     

Dietary phytase increases the true absorption and endogenous fecal excretion of zinc in growing pigs given a corn-soybean meal based diet

We investigated the effect of dietary phytase on the true absorption and endogenous fecal excretion of zinc (Zn) using ⁶⁷Zn in growing pigs given a corn-soybean meal based diet. Ten crossbred barrows were fed the control diet containing 90-mg/kg Zn, 2.3-g/kg phytate-phosphorus and 3.7-g/kg non-phytate-phosphorus or the phytase diet containing similar amounts of Zn and phytate-phosphorus, and 1.4-g/kg non-phytate-phosphorus with 750-PU/kg phytase for 12 h/day. On day 6, the pigs were given 200 g of the corresponding diet labeled by ⁶⁷Zn for 2 h. We measured feed intake, fecal Zn concentration and ⁶⁷Zn abundance for the determination of apparent absorption, true absorption and endogenous fecal excretion of Zn. Although the apparent absorption of Zn did not significantly differ between the dietary groups, the phytase group had significantly more ( P  < 0.05) true absorption of Zn than the control group. The endogenous fecal excretion of Zn tended to be more ( P  = 0.07) in the phytase group than in the control group. These results suggest that dietary phytase improves Zn bioavailability through increasing the true absorption of Zn in growing pigs, which results in stimulating the endogenous fecal excretion of Zn when dietary Zn satisfies its requirement.     

Dietary supplementation of potassium sorbate,hydrated sodium calcium almuniosilicate and methionine enhances growth,antioxidant status and immunity in growing rabbits exposed to aflatoxin B1 in the diet

The present experiment was conducted to evaluate the effect of dietary supplementation with some feed additives (potassium sorbate; Sor, hydrated sodium calcium almuniosilicate; Hsc and L-methionine; L-M) against aflatoxin B1 (AF) toxicity in rabbits. A total of 72 growing rabbits (5-week-old) were distributed into six equal groups (4 replicates with 3 rabbits each). The experimental groups are as follows: control group, AF group (supplemented with AF 0.3 mg/kg diet), AF + Sor group (AF 0.3 mg/kg diet + Sor 2 g/kg diet), AF + Hsc group (AF 0.3 mg/kg diet + Hsc 5 g/kg diet), AF + L-M group (AF 0.3 mg/kg diet + L-M 8 g/kg diet) and AF + Mix group (AF 0.3 mg/kg diet + 2 Sor + 5 Hsc + 8 L-M g/kg diet). Live body weight and weight gain at 13 weeks of age were significantly reduced by AF. Feed intake at 13 weeks of age was decreased in AF, AF + Hsc and AF + Mix compared to the control. AF, AF + Hsc and AF + Mix showed the lowest total antioxidant capacity compared to the control. The highest level of reactive oxygen species and 8-Hydroxy-2-desoxyguanosine was observed in AF group. Using of other supplements with AF increased immunoglobulinM than AF alone. In conclusion, dietary supplementation of Sor, L-M, Hsc or their mixture was effective in reducing the adverse effects of AF on performance, antioxidant and immune status of rabbits with more better improvement obtained by Sor or L-M separately.