Association of Residual Feed Intake to Metrics of Tanganyika Shorthorn Zebu Cattle in Maswa and Misungwi Districts, Tanzania

Abstract

Increasing competition for feed resources and greenhouse gases pollution have been compelling beef production systems to operate at higher feed utilization. These challenges imply the need to breed cattle for Residual Feed Intake (RFI) to lower feeding costs and enteric methane production per output. To explore relevant indicator traits of RFI, this study investigated the association of RFI to Tanganyika Shorthorn Zebu (TSZ) cattle metrics from the Misungwi and Maswa Districts of Tanzania, where Tarime and Sukuma ecotypes are common. A correlation study involving the fattening of twenty-eight TSZ bulls was conducted at Tanzania Livestock Research Institute -Mabuki. From the animals' body weight and feeding data, regression of daily feed intake on average daily gain and metabolic body weight was analyzed to estimate the animals' RFI. Subsequently, the correlation of RFI to metrics of belly, horn, hip, dewlap and body length was investigated. Residual Feed Intake and Belly Length (BeL) were highly positively correlated, while RFI and Dewlap Depth (DD) were moderately positively correlated. The results indicated prospects for using BeL and DD as indicator traits for RFI. Extensive studies are recommended to analyze the correlation of RFI to hump depth, ear length, muzzle circumference and kidney fat.