Experimental immunology
Influence of iron and immunomodulators on growth performance and immunohematological status of piglets

Introduction
Maintaining a good immune status helps animals to protect itself against pathogens [1, 2]. Low immune status may causes problems in animal production with high influence on production efficiency [2]. It is especially important in young animals, when passive immunity is lowered and adaptive immunity has not yet fully developed [3]. Nutritional means, including dietary supplementation with glutamine [4, 5] zinc [6], probiotics [7] or herbs [8] have been used to improve immunity of piglets. However, due to low feed intake in the first weeks of life, these approaches could be difficult to obtain [5, 9]. In modern intensive pork production system, pigs are weaned between 15 and 28 days of age [8, 10]. Weaning is associated with growth retardation as well as an increase in both, morbidity and mortality in piglets [8, 11]. This has led to the development of feed additives with high efficiency and low toxicity, in order to boost nonspecific the immune systems and improve the host defenses of young pigs during weaning [12].
Additionally, iron deficiency anemia (hypochromic, microcytic anemia) is well-known in piglets in early life [13, 14]. Anemia occurs because piglets are born with unusually small iron stores, milk contains low levels of iron, and pigs have a very rapid growth rate. During the first 4 weeks of life, the body weights of the piglets increase by about 4-fold. The dietary requirement for iron during this period is 7 mg per day, and only 1 mg per day can be supplied by the sow’s milk [13, 15-17]. The need to provide the piglets with an adequate amount of iron before weaning, is therefore essential because sow’s milk alone will not meet the iron requirements of rapid growth and expanding blood volume [15]. Anemia interferes with growth, and anemic pigs are lethargic and more susceptible to infection than healthy ones [11]. For that reason, beside iron supplementation, lots of products intended for pigs to prevent anemia contain also immuno-modulating agents.
Several different methods can be used to offer iron to young piglets. The most common administration method, is through an intramuscular or subcutaneous injection of iron. However, this method is very stressful to the piglets. Furthermore, it may cause trauma to the muscles [15]. That is why, an alternative methods need to be considered i.e. supply iron orally [15, 16].
This study was conducted to determine the efficacy of new commercial product...


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