The disposal of red grape pomace (GP) in landfills and by incineration has negative impacts on the environment. It is, therefore, imperative that alternative and sustainable ways of managing this waste product are identified. Using GP as a source of nutrients and beneficial bioactive compounds in avian diets is a potential waste-reduction and valorization strategy that promotes sustainable agriculture. However, there is limited information on the valorization of GP for this purpose. This study, therefore, investigated the effect of dietary inclusion of GP on growth performance, blood parameters, carcass characteristics, and breast meat quality traits of broilers. Four hundred, two-week old Cobb 500 broilers (279.2 ± 18.87 g) were allocated to 40 pens. Five isonitrogenous and isoenergetic diets were formulated by including GP in commercial broiler diets at 0 (GP0), 2.5 (GP25), 4.5 (GP45); 5.5% (GP55); and 7.5% (GP75). Feed intake, weight gain, feed utilization efficiency, hematology, serum biochemistry, carcass characteristics, and breast meat quality traits were measured. Chickens on GP75 had the least feed intake (p < 0.05) but there were no dietary effects on weight gain. Birds on GP0 had the highest (p < 0.05) feed conversion ratio (1.79) while those fed GP75 had the lowest (p < 0.05) ratio (1.45). Breast meat from broilers offered GP75 had the highest (p < 0.05) redness value (0.75) while the GP0 diet promoted the least (p < 0.05) redness value (0.49). Broilers fed GP55 and GP75 diets had higher (p < 0.05) feed conversion efficiency compared to GP0 birds. Inclusion of GP in broiler diets has the potential to reduce feed costs, thus making this valorization strategy a sustainable alternative to current pomace disposal methods. Adoption of this waste-reduction and valorization strategy promotes sustainable agriculture by contributing to food security and environmental stewardship.

The use of antibiotic growth promoters (AGP) in poultry production not only promotes the emergence of pathogenic multi-drug resistant bacteria, but it also compromises product quality, threatens animal and human health, and pollutes the environment. However, the complete withdrawal of AGP without alternatives could result in uncontrollable disease outbreaks that would jeopardize large-scale poultry intensification. Thus, the use of phytogenic products as potential alternatives to in-feed AGP has attracted worldwide research interest. These phytogenic products contain numerous biologically active substances with antioxidant and antimicrobial activities that can enhance poultry health, growth performance, and meat quality characteristics. In addition, the incorporation of phytogenic products as feed additives in poultry diets could result in the production of high-quality, drug-free, and organic poultry products that are safe for human consumption. Thus, this review examines the current evidence on the antioxidant and antimicrobial properties of a selection of phytogenic products, their effects on nutrient utilization, and physiological and meat quality parameters in poultry. The paper also reviews the factors that could limit the utilization of phytogenic products in poultry nutrition and proposes solutions that can deliver efficient and sustainable poultry production systems for global food and nutrition security.

In sub-Saharan Africa, the use of maize (Zea mays L.) grain as an energy source in poultry feeds has become unsustainable due to competing demands and suboptimal growing conditions for the maize crop. Sorghum (Sorghum bicolor Moench L.) and pearl millet (Pennisetum glaucum) grains are potential sustainable alternatives, given their tolerance to local growing conditions. Therefore, this study evaluated the effect of total replacement of maize grain with whole or crushed sorghum and pearl millet grains on feed intake, and physiological and meat quality parameters of Jumbo quail. Five experimental diets were formulated by completely replacing crushed maize grain in a commercial grower diet (CON) with whole sorghum (WSG), crushed sorghum (CSG), whole millet (WMG), or crushed millet (CMG). Three hundred and fifty, two-week-old Jumbo quail chicks (74.7 ± 8.81 g live-weight) were evenly distributed into 35 replicate pens to which the experimental diets were allotted. Statistically similar (P > 0.05) weight gain and FCE values were observed between birds reared on the control and pearl millet-based diets. However, birds fed with sorghum-based diets had the lowest FCE and weight gain. Blood parameters fell within the normal ranges reported for healthy quail. Birds fed the whole sorghum grain diet had the least (P < 0.05) serum calcium and higher monocytes, cholesterol, and alkaline phosphatase (ALP) concentrations compared to those reared on the control diet. Compared to the control, the whole sorghum-containing diet reduced (P < 0.05) carcass, breast, wing, thigh, drumstick, liver, gizzard, and large intestine weights of the birds. Complete replacement of maize grain with pearl millet grain (whole or crushed) did not compromise feed intake, growth performance, and meat quality traits of the Jumbo quail birds. However, whole sorghum grain reduced growth performance of the birds.