نوع مقاله : علمی پژوهشی- تغذیه طیور
1 دانشگاه تربیت مدرس، تهران
2 دانشجوی کارشناسی ارشد و استادیار دانشگاه تربیت مدرس، تهران
عنوان مقاله [English]
Introduction: The poultry industry has a crucial role in production of nutritious food for human consumption. Good quality feeds and rational nutrition are essential preconditions for obtain high producing healthy animals and economic prosperity in a flock. Antibiotics are worldwide used so far in animal husbandry to improve animal products, but nowadays the application of antibiotics as feed additives has been restricted. Therefore researchers have looked for new feed additives that are not harmful to human health. Previous studies related to humates have focused mainly on the growth of germinal tissue in seed. Humic acid based mixtures have the potential to be an alternative to antibiotic growth promoters in animal diets. The idea of using humates as feed additives in animal nutrition is new; in this research we investigated the effects of vermi-humus as an Iranian source of humic acid. Vermi-humus is final product of organic matter degradation by earth worms (Eisenia fotida). There are no information about nutritional effects of vermin-humus in poultry nutrition. The aim of the present study was to evaluate the effects of different levels of vermi-humus and virginiamycin on Japanese quail.
Materials and Methods: The treatments were considered as 6 levels of vermi-humus (0.2, 0.4, 0.6, 0.8, 1 and 2 %) and 0.15 % virginiamycin and a control diet in a randomized complete block design with 4 replicates and 10 birds in each cage. Therefore, 8 experimental dietary treatments were studied during 4 weeks. Water and feed were provided ad libitum, and lighting was continuous throughout the experimental period. The effects of these treatments were evaluated by general health indices such as growing performance, feed conversion ratio, viability, production efficiency factor, carcass percentage, relative organ weights, ileal microbial count, some serum biochemical indexes, and some meat quality parameters. The data were subjected to analysis using a General Linear Model procedure of SAS for the randomized complete block design. Differences between means were determined by Duncan’s multiple range test.
Results and Discussion: The lowest and the highest feed conversion ratio were related to 0.6 % vermi-humus and 2 % vermi-humus respectively. Dietary supplemention of different levels of vermi-humus did not influenced the viability percentage. There was no significant difference among birds that fed with supplemented diets with different levels of vermi-humus in compared with control group. in terms of Production efficiency factor. The lactic acid bacteria and streptococci counts in the 0.8 % vermi-humus were increased compared with other groups, moreover the Gram-negative bacteria count in this group showed a significantly reduction compared to other groups. The highest and the lowest concentration of serum cholesterol were observed in virginiamycin and 0.6 % vermi-humus, respectively. Serum triglyceride in the 0.8 % vermi-humus group showed a significantly decrease. The highest concentration of uric acid was observed in serum of birds that received virginiamycin. There was no significant difference among groups in terms of relative weights of heart, liver, proventriculus, and gizzard due to feeding vermin-humus. Also hematocrit, hemoglobin, High density lipoprotein, total protein, albumin, phosphorus, percentage of tibia ash and meat ash were not affected by experimental treatments. The highest concentration of calcium was observed in serum of birds that fed with 0.6 % vermi-humus. The highest meat fat contents were related to of 0.6 % and 0.8 % vermi-humus, also the highest water holding capacity was observed in these groups and treatments with 1 % vermi-humus had a minimum malondialdehyde concentration. The positive effects of humic acid as a feed additive in this study were supported by the other studies, although some others do not demonstrated any beneficial effect of humate substances. Performance differences due to humate supplementation observed in the literature might result from the compositional differences among the commercially available humate products.
Conclusion: Overall, these results show that supplementing Japanese quail diets with vermi-humus at a level of 0.6-0.8 % can be used to improve quality of bird’s products along with beneficial effects to birds and humans. Therefore vermi-humus might be promising alternatives for antibiotic growth promoters as pressure to eliminate antibiotic growth promoters in animal feed increases. The vermi-humus offers a good alternative to improve quails production. These results show that vermi-humus at level of 0.6-0.8 % can be used to improve quality of bird’s products along with beneficial effects to birds and humans.
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