AGRONOMIC AND GENETIC STRATEGIES FOR ZINC BIOFORTIFICATION OF MAIZE FODDER: IMPLICATIONS FOR DAIRY COW NUTRITION AND HEALTH

Abstract

Maize (Zea mays L) is a multi-purpose cereal used for both food and fodder purposes. Its fodder has many beneficial characteristics, such as palatability, silage quality, digestibility, and high energy density, making it a suitable option for dairy cows, but it has one major issue: low Zn content. Zn is one of the most essential micronutrients nutritionally for dairy animals as it is required for proper growth, development, and enzymatic activities. Current maize cultivars have very low Zn content; lower Zn content negatively affects dairy animals, causing diseases like parakeratosis and lameness, which also affect the animal's everyday life. To uplift Zn contents in maize fodder, biofortification is the most feasible option. The efficiency of Zn fortification is influenced by some factors, such as the technique used, genotype responses, soil properties, geographical parameters, and the requirements of farmers. Biofortification techniques, such as genetic and agronomic fortification, can be very helpful in enhancing the nutritional value of the fodder. Through these techniques, the Zn concentration in maize can be elevated according to the daily requirement of dairy cows. Future work should focus on the development of superior maize fodder varieties with increased Zn contents, along with their integration with proper agronomic practices specific to agro-ecological conditions. This review deals with the dietary importance of zinc in dairy cows, diseases caused by Zn deficiency in dairy cows, biofortification of maize with Zn, and methods used for biofortification of maize.