Impact of Dietary Supplementation on Growth Performance of Free-Range Chickens

Thesis Abstract

The rising demand for sustainable poultry production coupled with consumer preferences for free-range chicken products necessitates optimization strategies to enhance growth performance while maintaining animal welfare. Despite the increasing popularity of free-range systems, concerns persist regarding suboptimal growth rates attributed to nutritional limitations inherent in extensive rearing practices. This study aims to evaluate the impact of dietary supplementation on growth performance parameters in free-range chickens, with specific objectives to determine the effect of probiotic and mineral supplementations on body weight gain, feed intake efficiency, and carcass quality, as well as to assess potential interactions between different supplementation regimes. Employing a randomized complete block design, the research was conducted over a 16-week period at a commercial free-range poultry farm, involving a total of 180 indigenous broiler chickens aged 4 weeks. The birds were randomly assigned to three treatment groups a control group receiving standard scavenging diet, a probiotic supplementation group receiving 1?g/day of Bacillus subtilis-based probiotic in addition to scavenging, and a mineral supplementation group receiving 2?g/day of a mineral premix containing zinc, manganese, and selenium. Data were collected through weekly body weight measurements, feed intake records, and post-slaughter carcass evaluations. The validity and reliability of data collection instruments, including weighing scales and carcass assessment protocols, were ensured through calibration and standardization. Data analysis utilized ANOVA for comparing treatment effects, followed by Tukey’s HSD post-hoc tests for pairwise comparisons at a significance level of p < 0.05. Regression analysis was employed to explore relationships between feed intake and weight gain, while thematic analysis was considered for qualitative aspects of farmer perceptions obtained via structured interviews. Expected findings indicate that dietary supplementation, particularly with probiotics and minerals, will significantly improve growth performance metrics over the control, as evidenced by higher average daily gain, enhanced feed conversion efficiency, and superior carcass yield. It is anticipated that probiotic supplementation will stimulate gut microbial balance, leading to improved nutrient absorption, whereas mineral supplementation will optimize metabolic functions vital for growth. The study further expects to identify synergistic effects when combining supplementation strategies, offering insights into integrated nutritional practices for free-range systems. This research contributes to the existing body of knowledge by providing empirical evidence on the efficacy of specific dietary supplements in enhancing the growth performance of free-range chickens under tropical agro-ecological conditions. It advances understanding of nutritional interventions that align with sustainable poultry practices and addresses the gap concerning the combined effects of probiotics and mineral supplements within free-range management systems. Theoretically, the study supports the application of the Biological Enhancement Theory and the Nutrient Utilization Model to explain observed improvements in growth metrics. In conclusion, the study advocates for the integration of targeted dietary supplementation strategies into free-range poultry management to improve productivity and economic returns for smallholder farmers. Based on findings, practical recommendations include adopting probiotic and mineral supplementation protocols, optimizing supplementation doses, and training farmers on supplement administration. Future research directions suggest exploring longer-term impacts on reproductive performance and disease resistance, as well as evaluating the cost-benefit ratio of supplementation strategies in diverse ecological zones. This investigation underscores the potential of nutrition-based innovations to enhance growth efficiency in free-range poultry systems, contributing to food security and sustainable livestock production paradigms.