Effects of Animal Drinking Water Mineral Content on the Estimation of Magnesium, Copper, Iron and Manganese Digestibility and their Endogenous Losses in Growing Pigs by the Difference Method

Abstract

12 Yorkshire barrows with initial BW of 23.9 ± 1.1 kg were assigned to two dietary treatments with six replications per treatment. The two diets were formulated in accordance with the principles of the difference method. The minerals’ apparent and true digestibility (AD and TD) values as well as their endogenous fecal losses (EFL) were to be investigated. The pigs were randomly allotted to their individual feeder pens which enabled individual pig fresh fecal sample collections. The experiment was designed as a completely randomized design (CRD) and lasted for 15d consisting of 10d adaptation to diets and 5d of spot fecal collections. Results showed negative AD values for all the minerals studied, namely Mg, Cu, Fe and Mn. Therefore, their TD values and their EFL could not be estimated because of their negative AD values. Further investigations revealed that the negative AD values of the minerals were due to high levels of calcium (Ca) in the animals’ drinking water during the study period. It was concluded that determination of apparent and true digestibility values of Mg/trace minerals and their endogenous losses also require measurement of drinking water mineral sources and intakes as to avoid excess mineral intakes in order to avoid mineral antagonisms and digestibility.