Feed physical form (mash vs . pellets) in layer and breeder chickens: implications for performance, gut function, and practical feeding strategies

SUMMARYThis review synthesizes experimental and field data on pelleted versus mash diets in layers, breeders, and grandparent flocks. Pellets may improve early growth and FCR (by 5–10% in pullets), but they may also result in underdeveloped gizzards and reduced fertility. Mash diets could promote gizzard development, hatchability (by up to 8% in breeders), and flock uniformity across production phases. A novel synthesis suggests that stage-specific feeding strategies (such as chick pellets followed by grower mash) may optimize performance, gut health, and economics. Field cases indicate that mash may be superior for reproduction under heat stress. Chicks may thrive on crumbles or pellets for accelerated early growth, whereas growers and pre-layers may respond better to coarse mash, which promotes skeletal development and flock uniformity. Feeding mash to laying hens has been shown to improve egg quality and maintain high productivity over time. In breeder and grandparent stocks, mash diets are associated with improved fertility and hatchability. This review combines experimental data with detailed field case studies to reconcile differing opinions and provide useful, age-appropriate recommendations. Feed form should be viewed not as a fixed decision but as a dynamic strategy tailored to bird age, production goals, and prevailing farm conditions.