IMPACT OF FOLIAR ZINC BIOFORTIFICATION ON SORGHUM FODDER: A STRATEGY FOR IMPROVED LIVESTOCK NUTRITION

Abstract

Sorghum (Sorghum bicolor L.), a critical dual-purpose crop, faces micronutrient limitations that undermine its viability as livestock feed. Zinc deficiency is pronounced in sorghum-based feed. Hence, to increase the zinc contents of sorghum fodder, the present study investigated zinc sulphate foliar application (0, 0.5, 1.0%) across four cultivars (Sorghum-263, JS-2002, Hegari, Sorghum-2011). The experiment was conducted at the University of Agriculture, Faisalabad, Pakistan, using a completely randomized design (factorial) with three replications. Results depicted that the 0.5% zinc treatment consistently outperformed other concentrations, irrespective of cultivar. Agronomically, it maximizes plant height (+18% vs. control), leaf production (+24%), and fodder yield (green and dry matter by 31% and 28%, respectively), alongside boosting chlorophyll synthesis. Nutritionally, it elevated crude protein (10.75% vs. 8.2% in control) and zinc concentration (153.13 vs. 89.4 mg kg⁻¹) while reducing fiber fractions (26.03% fiber, 61.91% NDF, 32.18% ADF), enhancing overall digestibility. These results establish 0.5% zinc sulphate as a cost-effective foliar strategy to concurrently elevate sorghum's biomass productivity and nutritional value, addressing micronutrient gaps in livestock diets. The study promotes targeted zinc management to fortify fodder systems against nutrient deficiencies in livestock