Oorsig/Review
in a study conducted by Ferguson et al. (2004)
where feeding complexed organic trace minerals
to cows that experienced a transition health
disorder, improved reproductive performance
(i.e., pregnancy rates) to a level similar to that
of cows that never experienced a transition
disorder. The same results did not occur when
only inorganic trace minerals sources were fed
(Figure 9; Ferguson et al., 2004).
Inflammation and the Mammary Gland
In the mammary gland, the keratin plug of the teat
is one of the first lines of defense to protect the
animal from a mammary infection (i.e., mastitis).
Feeding zinc from complexed organic trace
minerals has been shown to increase teat keratin
production in cows, which may protect the
cow from a mammary infection (Jones, 1995).
Furthermore, elevated somatic cell counts (SCC)
in milk are a key indicator of mammary gland
inflammation (Pyörälä, 2003), and numerous
studies have confirmed that feeding complexed
organic trace minerals decreases SCC in lactating
dairy cattle (Kellogg et al., 2003, 2004; Sobhanirad
et al., 2010; Nayeri et al., 2014). A 12-trial
tetrabasic chloride (ZnCl). In both the thermal-
neutral and heat-stress phases, plasma lactose
increased in cows receiving only zinc from ZnCl
but remained unchanged in cows consuming zinc
from complexed organic trace minerals. These
results indicate that feeding zinc from complexed
organic trace minerals in place of ZnCl better
maintains mammary tight junction integrity,
which is crucial for milk secretion and avoiding
milk leakage from the lumen of alveoli (Weng et
al., 2016).
INFLAMMATION AND THE
ADAPTIVE IMMUNE SYSTEM
The adaptive immune system differs from the
innate immune system in the sense that it has
the ability to recognize specific antigens and
has a memory function. In contrast, the innate
immune system does not have memory, includes
anatomical features that prevent bacterial entry
into the body and binds to general classes of
bacterial or viral antigens. Components of the
innate immune system include epithelial barriers,
Figure 10 - The impact of complexed organic trace minerals on Somatic Cell Count
summary indicated that feeding cows zinc from
complexed organic trace minerals reduced SCC
on average by nearly 100 (1000/mL; Kellogg et
al., 2004; Figure 10).
Although SCC is a reliable indicator of
inflammation within the mammary gland,
integrity of the mammary epithelium is also of
paramount importance. Recent data indicates
that zinc from complexed organic trace minerals
may impact mammary gland epithelial integrity.
In this study, mid-lactation cows subjected to
either thermal-neutral environments or heat-
stress conditions were fed 40 ppm zinc from
either complexed organic trace minerals or zinc
8
macrophages, granulocytes, mast cells and
natural killer cells. Binding to specific peptide
sequences would be reserved for the adaptive
(acquired) immune system components and
their memory-like function. Components of the
adaptive immune system include B-lymphocytes
(10 percent to 20 percent of circulating
lymphocyte population) and T- lymphocytes (60
percent to 70 percent of circulating lymphocyte
population). For simplicity sake, data from
multiple cell classes will be discussed herein,
although they may not be specific to the adaptive
immune system, as many of these cell types work
in concert to mount an inflammatory event and
successful immune response.