10th U6+ Consortium of African Universities International Conference

Bone meal is valuable by product of the livestock industry widely used as a source of essential minerals in animal feed and organic fertilizers. However, the mechanical properties and nutritional composition of bone meal is significantly influenced by the type of bone tissue, processing conditions (heat treatment and duration), particularly in low-resource settings where temperature regulation is usually lacking. This study evaluated the effect of heat treatment temperatures and duration on mechanical strength, nutrient composition and nutrient retention in bone meal derived from three bovine tissues of ribs, femur and hooves. A two-factor factorial experiment was conducted under a completely randomized design (CRD) with bone tissues subjected to controlled temperatures 100oC, 200oC, 300oC and duration (30min and 60min). Mechanical properties evaluated included mechanical strength, and sieving properties. While nutritional parameters studied were moisture, total ash, crude protein, crude lipids as well as acid insoluble ash (AIA) and minerals calcium, phosphorus. Data were analyzed using one – way and three-way ANOVA with Tukey’s HSD test. Results showed that heat treatment temperature (p< 0.001), tissue type (p< 0.001), and their interaction (p< 0.001), significantly affected the mechanical properties, nutrient composition and nutrient retention. There was a progressive reduction in moisture and crude lipid content across all bone types with increasing temperature, with nearly complete lipid degradation at 300oC. Ash and AIA content increased significantly with temperature (p< 0.001), indicating organic matter loss. Calcium and phosphorous were stable up to 300oC but declined significantly at, especially in ribs (p< 0.001). Femurs retained the highest mineral content across treatments, while hooves showed the greatest resistance to lipid loss. The conclusion is that heat treatment and tissue type significantly affect nutrient retention. Moderate processing (100oC and 200oC) optimize nutrient preservation while higher temperatures (300oC), lead to substantial losses especially of the vital minerals (calcium and phosphorous) and lipids. These findings support the development of tissue-specific, temperature-controlled processing protocols to improve the nutritional quality and safety of bone meal, thereby informing feed standards and agro-industrial policy in resource-constrained countries like Uganda.