Probiotics as a Promising Additive in Broiler Feed: Advances and Limitations

Feed additives have a strong influence on the production cost of broilers as growth-promoter’s to cover variations in profits due to fluctuation in feed costs. Antibiotics as additives were fundamental and indispensable, however, studies have shown their connection with the emergence of resistant strains of pathogens in animals and humans, therefore in recent years they have been less encouraged. Research is in progress concerning additives that can replace antibiotics as growth promotors and also as prophylactics. It was demonstrated that probiotics, which are living microorganisms and without residual effect’s have a potential to be used as microbials. However, they are not always guaranteed as growth promoters, as there are mechanisms of action regarding their interaction with the host that cannot yet be properly understood. The main advances in the use of probiotics in broilers in recent years, as well as the gaps, challenges, and future perspectives were carefully discussed and analyzed in this study. It was considered as a future premise, the possibility of reviewing the traditional methodologies used to test the hypotheses related to the effect of probiotics in broilers, which may also be extended to other animal species.

The Effects of Heat Stress on Production, Reproduction, Health in Chicken and Its Dietary Amelioration

Farm profitability is the key driver of most livestock enterprises. The productivity and profitability are driven by genetic potential of the animals and the ability to express the superiority in the production environment. In an ideal situation, an animal should produce maximally as dictated by the genetic potential. It is noteworthy that the environment in which an animal lives in impacts on its ability to expose its genetic potential. Studies have shown that it is rarely feasible to provide animals with ideal conditions to express their full genetic potential. The environment in which animals are reared is characterised by many factors that interact in ways that result in different performance even in animals of similar genetic makeup. For instance, thermal environment is critical in poultry production as it affects both the production and reproduction in different ways. The thermal environment affects chicken differently depending on the stage of growth or production phase. This environment has been impacted by the climate change and subsequent increase in climatic variability resulting in thermal challenges in naturally produced chicken thus altering production and reproduction. This implies that there is need to consider thermal resource in the routine poultry management practices. This would result to design of poultry production systems responsive to the thermal environments more so in the light of climate change and the subsequent increase in climatic variability. This chapter explores the impact of heat stress on chicken production, reproduction, health and its dietary amelioration.