EFFECT OF DIETARY ADDITION OF ZINC ENRICHED SPIRULINA ON GROWTH AND PHYSIOLOGICAL PERFORMANCE IN GROWING RABBITS.

Document Type : Original Article

Authors

Animal Production Research Institute, Agricultural Research Center, El-Dokki, Giza,, Egypt.

Abstract

The present experiment was carried out to evaluate the effects of Zinc-enriched Spirulina (Zn-Sp) supplementation as an organic Zn source on the growth performance, nutrients digestibility, carcass characteristics, blood parameters and economic efficiency of growing rabbits. A total of forty eight male NZW rabbits (35 days old) were allotted to four groups (12 rabbits for each), 4 replicates (3 rabbits for each). Three levels of Zn-Sp (50, 75 and 100 mg Zn-Sp/kg diet) were compared to a control group without Zn-Sp addition.The results have shown that dietary Zn-Sp supplementation caused an increase (P<0.05) in final live body weight at 13 weeks. Supplementation of 75 and 100 mg Zn-Sp improved (P<0.05) body weight gain compared to the control group during the whole experiment period. The increases in body weight gain were 10.93 and 10.63% for 75 and 100 mg Zn-Sp, respectively compared to the control group. On the other hand, at all experimental periods, rabbits fed diets supplemented with 75 and 100 mg Zn-Sp consumed less (P<0.05) feed intake than those fed control diet or 50 mg Zn-Sp. As well as, diets supplemented with Zn at 50, 75 and 100 mg Zn-Sp improved (P<0.05) FCR throughout the experimental period (8weeks). Dietary Zn-Sp supplementation at 100 mg led to a significant increase in all nutrients digestibility In addition; Zn-Sp supplementation had insignificant effect on the CF digestibility. Feeding rabbits on diets supplemented with Zn-Sp at a level of 100 mg/kg DM increased (P<0.05) DCP%, TDN and DE (kcal/kg) compared to the control group. The obtained results also showed that supplementing rabbit diets with Zn-Sp at each tested level increased (P<0.05) hot carcass weight, dressing percentage, total edible parts (%), serum total protein and HDL, serum Zn concentrations, total antioxidant capacity (T-AOC) levels in comparison to the control group. Conversely, a significant decrease (P<0.05) was observed in serum total cholesterol and LDL concentrations compared with the rabbits fed the control diet. The economical efficiency of diets supplanted with 50, 75 and 100 mg Zn-Sp increased by 14.94, 33.0 and 33.48% over the control group.
In conclusion, the present results indicated that supplementation of Zn-Sp could be used as an organic source of Zinc for rabbits. It has more bioavailability and caused an improvement in growth performance and digestibility without any adverse effects on the health status of rabbits.     

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