Previously, fermentation has been associated with methods that improve the nutritional value of unconventional feed ingredients for broilers. In recent decades, the fermentation process has been employed to produce functional feeds that have the potential to improve broiler gastrointestinal tract microecology, health and production performance. Some of the functional ingredients found in fermented feed include lactic acid bacteria (LAB), lactic acid and other organic acids, and appear to play major roles in determining the beneficial effects of fermented feed on broiler gut health and performance. Unlike the pig, the available literature on broiler fermented feed is still rather limited. This review describes recent advances in the use of fermented feed (on the basis of conventional and unconventional feed ingredients) in broilers. Similarly, this review also shows that additional research is necessary to exploit fermented feed as a viable food source in broiler nutrition.

Heat-related stress has become a serious problem in poultry industry along with the global temperatures rise. Heat stress causes detrimental effects on physiology, immunology and microbiology resulting in abnormalities and impaired performances of birds. Several nutritional strategies have been conducted to counteract the detrimental effects of heat stress in poultry, including dietary supplementation of probiotics. This strategy has been proposed to ameliorate the intestinal ecosystem, physiological conditions and immune system, leading to the improved performance and health of birds subjected to heat stress. This review presents the potential benefits of probiotics against heat stress in poultry from the viewpoint of intestinal microbial ecology, morphology and structure, physiological conditions, immune system and production performances. The possible mechanisms through which probiotics may give beneficial impacts on heat-stressed birds are also discussed along with the data reporting the possible drawbacks of using probiotics in heat-stressed poultry.

Stocking broilers at a high density has been a strategy to optimize the area of the cage and hence increase the efficiency of broiler production. If the environmental (microclimate) conditions and rearing management are not properly managed, stocking broilers at a high density may, however, result in stressful conditions that are harmful for the production, health and welfare of broilers. To ameliorate these unfavorable effects of overcrowding stress, dietary interventions have been conducted. Probiotics, prebiotics, synbiotics, plant-derived products, vitamins, propolis, amino acids, fatty acids, etc. have been supplemented in diets to deal with the harmful impact of stress induced by a high stocking density of broilers. This review covers the detrimental effects of overcrowding-induced stress on broiler development and attempts to ameliorate those negative effects by dietary interventions.

The antioxidant capacity and antioxidant constituents of two filamentous fungi (Acremonium charticola and Rhizopus oryzae) isolated from the Indonesian fermented dried cassava (gathot) were evaluated in the present study. The antioxidant capacity of the fungal crude extracts was assessed based on the 2,2′-azino-bis(3-ethyl-benzthiazolin-6-sulfonicacid) (ABTS) method. Total phenolics were determined based on the Folin-Ciocalteu method, while the flavonoids content in the fungal extracts was determined by the spectrophotometric method with aluminum chloride. Total tannins were estimated by the Folin-Denis method. The ABTS⁺ radical scavenging activity was higher (p < 0.01) in A. charticola compared to that in R. oryzae and ascorbic acid (as a control). A higher (p < 0.01) content of total phenolics was detected in A. charticola than that in R. oryzae. Total flavonoids were higher (p < 0.01) in R. oryzae as compared with that in A. charticola. The fungus A. charticola had a higher (p < 0.01) level of total tannins than R. oryzae. In conclusion, both filamentous fungi isolated from the Indonesian fermented dried cassava exhibited antioxidant potentials as indicated by their capabilities to scavenge ABTS⁺. A. charticola had a higher antioxidant capacity than R. oryzae. The antioxidant capacity of A. charticola was attributed mainly to its phenolics and tannins contents.

The steady increase in the price of protein feed ingredients and the retraction of antibiotics from diets has encouraged nutritionists to search the alternatives for protein source and functional feedstuffs that can substitute the role of antibiotic growth promoters in poultry production. With crude protein of 24-30%, in vitro protein digestibility of 80% and proportion of essential amino acids of 47%, seed from ripe papaya may be exploited as the alternative protein feed ingredient for poultry. Moreover, the growth promoting effect, antimicrobial and antiparasitic activities, and immunomodulatory and antioxidative activities may confirm the potential of papaya seed as a functional feedstuff that could replace the role of antibiotic growth promoters for poultry. The in-depth study is needed to further elucidate the functionalities of papaya seed on poultry. This review provides the updates on the nutritional contents of papaya seed, the potential of papaya seed as an alternative to conventional protein-rich ingredient, the growth-promoting effect of feeding papaya seed, the antimicrobial and antiparasitic activities of papaya seed, antioxidative activities of papaya seed, and the immunomodulatory activity of papaya seed on poultry.

Effect of supplementation of multistrain probiotic preparation in combination with vitamins and minerals to the broiler chicken diets on their growth performance, hematological parameters, and carcass traits