Abomasal infusion of essential fatty acids and conjugated linoleic acid during late pregnancy and early lactation affects immunohematological and oxidative stress markers in dairy cows
Author(s)
Date Issued
2023
Type
article
Volume
106
Journal
Abstract
Oxidative stress and inflammation, as natural parts
of metabolic adaptations during the transition from
late gestation to early lactation, are critical indicators
of dairy cows’ metabolic health. This study was designed to investigate the effects of abomasal infusion
of essential fatty acids (EFA), particularly α-linolenic
acid, and conjugated linoleic acid (CLA) on plasma,
erythrocyte, and liver markers of oxidative stress
in dairy cows during the transition period. Rumencannulated German Holstein cows (n = 38) in their
second lactation (11,101 ± 1,118 kg milk/305 d, mean
± standard deviation) were abomasally infused with
one of the following treatments from d −63 antepartum until d 63 postpartum (PP): CTRL (n = 9; 76
g/d coconut oil); EFA (n = 9; 78 g/d linseed plus 4
g/d safflower oil); CLA (n = 10; isomers cis-9,trans-11
and trans-10,cis-12 CLA; 38 g/d); and EFA+CLA (n
= 10; 120 g/d). Hematological parameters as well as
markers of oxidative status were measured in plasma,
erythrocytes, and liver before and after calving. Immunohematological parameters, including erythrocyte
number, hematocrit, hemoglobin, mean corpuscular
hemoglobin, leukocytes, and basophils, were affected
by time, and their peak levels were observed on the day
after calving. The oxidative stress markers glutathione
peroxidase 1 and reactive oxygen metabolites in plasma
and erythrocytes were both affected by time, exhibiting the highest levels on d 1 PP, whereas β-carotene,
retinol, and tocopherol were at their lowest levels at
the same time. Immunohematological parameters were
only marginally affected by fatty acid treatment in a time-dependent manner. As such, lymphocyte and
atypical lymphocyte counts were both significantly
highest in the groups that received EFA at d 1 PP.
Moreover, EFA supplementation increased the mean
corpuscular volume and showed a trend for induction
of mean corpuscular hemoglobin compared with the
CLA group during the transition period. The PP mean
thrombocyte volume was higher in the EFA than in
the CLA group (except for d 28) and both EFA and
CLA reduced number of thrombocytes and thrombocrit
at distinct time points. Hepatic mRNA abundance of
markers related to oxidative status, including glutathione peroxidase (GPX-1) and catalase (CAT), was
lower (P < 0.05) in EFA-treated than non-EFA-treated
cows at d 28 PP. Dairy cows at the onset of lactation
were characterized by induced markers of both oxidative stress and inflammation. Supplementing EFA and
CLA had minor and time-dependent effects on markers
of oxidative stress in plasma, erythrocytes, and liver.
A comparison of EFA supplementation with CLA or
CTRL showed higher immunohematological response
at d 1 PP and lower hepatic antioxidant levels by d 28
PP. Supplementation with EFA+CLA had only a minor
effect on oxidative markers, which were more similar to
those with the EFA treatment. Altogether, despite the
time-dependent differences, the current findings show
only minor effects of EFA and CLA supplementation
in the prevention of early lactation-induced oxidative
stress.