Effects of Iron Supplementation on Metabolism in Calves Receiving Whole Milk

SIMPLE SUMMARY: Young animals in the early stages of life are most susceptible to iron deficiency; however, neonates do possess a certain degree of iron reserves in their body. Moreover, in the case of feeding calves with cow’s milk, which has a low iron concentration, rapid growth rates can lead to the development of temporary iron deficiency. This condition may be exacerbated by the immaturity of molecular mechanisms in relation to iron absorption. Further, iron supplementation is based primarily on inorganic compounds. However, these compounds can undergo oxidation and transform into insoluble forms. For the purposes of animal nutrition and to increase the bioavailability of this element, this research focuses on the use of chelates or proteinaceous iron preparations. Casein proteins possess excellent iron-binding properties, thereby decreasing their susceptibility to oxidation and therefore possessing high bioavailability. ABSTRACT: The objective of this study was to determine the effects of feeding a protein–iron complex (PIC) to calves. Specifically, the aim was to understand how it influences productive performance and indicators of iron metabolism, hematology and biochemical and parameters during feeding with whole milk before weaning. The study was carried out on 20 Polish Holstein Friesian calves. The calves were then divided into a control group (CON), fed with full milk (n = 10), and an experimental group (MFe), who received a PIC additive in milk at 16 g/day (n = 10). In order to determine the production parameters, the calves were weighed at the beginning (i.e., on the 7th day of life) and at the end of the experiment (42nd day of life) using an electronic platform scale. Production parameters such as average weight gain (AWG), feed conversion ratio (FCR), and growth rate (GR) were assessed. Blood was collected from an external jugular vein (vena jugularis externa) on the 7th, 14th, 28th, and 42nd days of life. The mean daily gains in body weight (ADG), growth rate (GR), and the feed conversion ratio were highest in the experimental group, MFe. Therefore, it can be concluded that the addition of a protein–iron complex entailed a significant impact on the iron metabolism indicators in the MFe experimental group.