1. INTRODUCTIONAntibiotics were used world wide in poultry industry, to prevent poultry pathogens and disease so as to improve meat and egg production. However, dietary supplementations of antibiotics resulted in common problems such as development of drug-resistant bacteria, drug residues in the birds tissues [1], and imbalance of normal micro flora [2] As consequences, it has become necessary to develop an alternative using beneficial live microorganisms that enhance microbial growth in the host digestive tract. In recent years, the use of probiotic and prebiotic in poultry diet has become popular as an alternative substances to antibiotic for animal production which is concerned to human health [3,4]. In case of probiotics, lactic acid bacteria such as lactobacilli streptococci and bifido bacteria are the most common organisms used. The mechanism of action of probiotics is not known precisely although there are several hypotheses. The mechanism of actions has not been fully explained. Shams et al. [5] reported that the reductions of blood cholesterol level were due to dietary inclusions of using symbiotic in meat chickens. Liong and Shah [6] achieved the results by dietary supplementations of symbiotic will cause regulation the concentration of organic acids and reduction of blood cholesterol level broiler. Shahin et al. [7] reported that symbiotic in quail ration will meaningfully affect blood cholesterol and total protein. Dibaji et al. [8] reported that dietary inclusions of probiotics (Biomin IMBO) also did not interfere on blood cholesterol, total protein, blood albumin, HDL and VLDLI, triglyceride, uric acid and glucose levels significantly. Sharifi et al. [9] in their experiment by using probiotics in bird’s diet, feed efficiency, blood cholesterol and total protein of japans quails were not shown any significant differences. Awaad et al. [10] reported that, improvement of feed efficiency was observed by inclusions of probiotics in broiler chick. Hence, due to antibiotic resistance bacteria in poultry product, which will be health hazardous to the human, substitution of antibiotic with use of probiotic as a safe product, to improve laying bird’s performance through dietary supplementations of said probiotics. Probiotic Biomin Imbo, is one of beneficial substances with colony numbers such as (cfu/kg media, 5 × 1011) and it contains, 1-Enterococcus faecium (keeps away pathogens—a beneficial gut microflora is established and maintained), 2-Prebiotic (fructo-oligosaccharides selectively stimulate the growth of beneficial Bifidobacteria in the large intestine (bifidogeniceffect) and thus defeat pathogens, 3-Cell wall fragments strengthen the innate immune system. They modulate important cells of the immune system and therby improve resistance to infections. Cell wall fragments also block specific receptor-binding sites for pathogens and help to prevent pathogen adherence, 4-Phycophytic substances are derived from sea algae. Together with phytogenic matters, they strengthen the anatomic barrier against the invasion of pathogenic bacteria. The objective of this study was to determine if experimental supplementation of different level of probiotic (Biomin IMBO) in laying hen diet may improve the performance and other economic characteristics of studied birds.
3. RESULTS AND DISCUSSIONAll birds Feed ingredients and its chemicals compositions and the effect of different levels of probiotic on egg production, feed efficiency and egg mass during the experimental period is shown in Table 1. A significant increase in egg production was recorded in laying birds which was fed diets supplemented with probiotics (p < 0.01). As result was revealed, birds fed with probiotics at different levels performed well at the commencement of the experiment. While, with advancing age of birds, probiotics had an increasing trend on overall performance of birds. The highest and the lowest egg production was observed in diets supplemented with probiotics at the levels of 750 g/t feed and control groups respectively and
Table 1. Feed stuff and chemical composition of experimental base ration.
*Each kg of this premix contains the following amounts: Vitamin A 3,520,000 IU, Vitamin D3 1,000,000 IU, Vitamin E 4400 IU, K3 800 mg, B1 591 mg, B2 3136 mg, B5 13,860 mg, B6 985 mg, B9 200 mg, B12 4 mg, H2 60 mg, Colin Chloride 120,000 mg, and Antioxidant 400 mg. **Each kg of this Premix contains the following amounts: magnesium 29,760 ppm, Zinc 25,870 ppm, Iron 30,000 ppm, Copper 2400 ppm, Iodine 351 ppm, Selenium 80 ppm, and Colin Chloride 60,000 mg.
differences were significant (p < 0.01). Whereas, different levels of dietary inclusions of probiotics did not show any significant differences among them in egg productions. This result was in accordance to the finding of Shivani et al. [13] and Chen and Nakthong [14]. It is assumed that, lactobacillus in probiotics will enhance nutrient availability and absorptions in the bird’s digestive tract which will increase egg production. The increased egg productions will be assumed by influence of lactobacillus in probiotics Whereas, this findings were in contrast to the reports of Zarei and Ehsani [15]. Feed intake was considered as constant (at the levels of 110 g/hen/day) through out the experimental period. Egg mass was affected by dietary inclusions of probiotics within on set of 2nd phase production (i.e. 6th week onwards). Probiotics at 750 g/t feed increased egg mass drastically as compare to control and other experimental groups (p < 0.01). These findings were in accordance with Haddadin et al. [16]. In which they assumed more number of lactobacillus in probiotics will boost and improve the digestibilities of nutrients which finally interfere in enhancing egg mass significantly. Nevertheless, some results were in contrast with the present reports. Zareei, et al. [15] reported that, dietary probiotics did not influence on egg mass. As Table 2 indicated that, feed efficiency of the laying hens in different treatment groups were significantly different with the presence of probiotics (p < 0.01). According to the results presented in Table 2, the highly improved feed efficiency (1.93) was observed in diets containing probiotics at levels of 750 g/t feed, as compare to other experimental groups (p < 0.01). These findings were in accordance with the reports of Awad et al. (2009). Nevertheless, Zareei et al. [15], reported that, probiotics did not show any influence on improvement of feed efficiency of the chickens. Overall results indicated that, birds fed diets with different levels of probiotics had 11.40%, 13.16% and 13.13% had higher mean feed efficiency, mean egg production and mean egg mass respectively. In case of egg quality, during 30 d of egg productions, yolk color and hugh unit were affected significantly by dietary inclusions of probiotics at the levels of 750 g/t feed as compare to other experimental groups (p < 0.05). Though, on set of experiment, probiotics did not show any significant differences. Other criteria such as, egg shell thickness, egg yolk and blood serum cholesterol, did not alter by dietary inclusions of probiotic at various levels significantly, but as numerically egg yolk cholesterol were reduced by dietary probiotics at 500 g/t feed as compare to control groups. The results of this experiment were in contrast with the findings of previous studied works [5-7], but it was in agreement with the findings of other studies [8,9,15].
Even though, dietary probiotics did not effect significantly on It is assumed the hygiene and ideal environmental conditions of farm influenced on effects on multiplications of lactobacillus present in probiotic in birds digestive tracts, caused uncertainty of disease conditions to be occur in the farms. As Table 3 indicates, data were observed in concerned parameters such as WBC, Monocyt, Aozenophyl, lymphocyt and Heterophyl which are related to immune responses and also blood cholesterol of laying birds did not show significant differences by feeding diets supplemented with probiotics. Results of this experiment were in agreement of other scientist’s reports [8,9,15]. They reported that, the ideal conditions of productions, beneficial bacteria in probiotic will not interfere in immune responses of birds. Nevertheless, some of reports are in contrast with these findings, which have been delighted significant effect of probiotics on reducing levels of cholesterol in bird’s blood [5-7], whereas, other reports were in agreement of this result [15].
As shown in Table 3, the levels of blood total proteins were increased numerically as levels of probiotics in diets were increased. The higher and lower blood total proteins were owed to diets containing probiotics at the levels of 750 g/t feed and control groups respectively and differences were not significant. These results were in
Table 2. Effects of experimental diets on performance of laying hen.
**Mean bears not common superscript are different significantly (p < 0.01).
Table 3. Effects of experimental diets on blood parameters of laying hen.
ns = Mean bears not common superscript are not different significantly (p < 0.05).
contrast with the findings of Shahin et al. [7], whereas, it was in agreement with the reports of other Iranian research observations [8,9].
