Document Type : Research Paper

• Animal Nutrition and poultry

Extended Abstract

Introduction

Global population growth, particularly in the present century, underscores an escalating demand for high-quality protein, notably of animal origin. The Food and Agriculture Organization (FAO) has reported rising poultry meat consumption in developing countries, a trend that has increased both demand for and the cost of feed ingredients. In 2006, the European Union prohibited the use of growth-promoting antibiotics in livestock and poultry diets to mitigate the emergence of antimicrobial resistance in humans. However, the removal of antibiotics can adversely affect poultry health and elevate production costs. Protein sources constitute a substantial fraction of poultry rations and represent a major contributor to the cost per kilogram of feed. Optimizing performance by minimizing protein wastage can therefore reduce production expenses. Conversely, excess dietary protein may increase water intake and litter moisture, thereby predisposing flocks to problems such as breast blisters, footpad dermatitis, dysbiosis, and coccidiosis. The use of feed additives in poultry nutrition has been proposed to enhance feed utilization and sustain gut health. In recent years, postbiotics and paraprobiotics—derivatives of probiotic cultures—have been applied in humans, livestock, and poultry to support the intestinal microbiome and inhibit the adhesion of pathogenic organisms, particularly during early life stages.

Materials and Methods

A total of 200 one-day-old male broiler chicks (Ross 308) were used in a 42-day trial arranged as a completely randomized design with five dietary treatments, four replicates per treatment, and 10 birds per replicate. The treatments were: (1) balanced crude protein diet; (2) low-protein diet (95% of requirements) without additives; (3) low-protein diet (95% of requirements) plus postbiotic; (4) low-protein diet plus 0.02% probiotic; and (5) low-protein diet plus 0.03% multhiomycin. Postbiotic was included at 0.15% in the starter diet, 0.10% in the grower diet, and 0.05% in the finisher diet. The probiotic (Lactofeed) was provided at 0.02% throughout the entire period, and multhiomycin at 0.03% of the diet.

Results

In the starter period, chickens fed with the treatment containing 0.03% multhiomycin had lower feed consumption than other treatments. Chickens fed a balanced protein diet had the highest conversion ratio and chickens fed a low protein diet + 0.03% multhiomycin had the lowest conversion ratio during the growth period. In the final period, each of the performance traits, average weight gain, feed intake, and feed conversion ratio, was not affected by the experimental treatments. Throughout the total period, chickens fed the low protein diet + 0.03% multhiomycin had significantly lower average weight gain and feed consumption than the other groups. The treatment fed with low protein diet + 0.03% multhiomycin had a lower carcass weight percentage than the other groups, and the treatment fed with low protein diet + 0.02% probiotic had a higher carcass weight percentage than the other groups. Chickens fed a low protein diet + postbiotic had the highest thymus percentage, and the control treatment (with balanced crude protein) had the lowest percentage of thymus weight compared to other groups. The second treatment (low protein diet without additives) had the highest percentage of spleen weight and the fifth treatment (low protein diet + multhiomycin) had the lowest percentage of spleen weight. No significant differences were observed between the experimental treatments in terms of total population traits of aerobic bacteria, Lactobacillus, and Escherichia coli.

Conclusions

The results of the present experiment showed that, use of low protein diet without and with adding postbiotic and probiotics had not significant effect on performance of broiler chicks   compared to the control group and due to reducing of soybean mea in such diet, it reduces the cost of broiler chicks diet.

Author Contributions

All  authors  contributed  equally  to  the  conceptualization  of  the  article  and  writing  of  the original and subsequent drafts.

Data Availability Statement

Data available on request from the authors.

Acknowledgements

The authors would like to thank the Knowledge-Based Company of Bahan Kimia Enzyme and all those who helped us in conducting this research.

Ethical considerations

The study was approved by the Ethics Committee of the Sari Agricultural Sciences and Natural resources University (Ethical code: IR.UT.RES.2024.500). The authors avoided data fabrication falsification, plagiarism, and misconduct.

Conflict of interest

   The author declares no conflict of interest.