High-Concentrate Feeding to Dairy Cows Induces Apoptosis via the NOD1/Caspase-8 Pathway in Mammary Epithelial Cells.

(1) Background: The effects of a high-concentrate (HC) diet in inducing mammary epithelial cell apoptosis in dairy cows via the NOD1/Caspase-8 pathway have never been investigated before the current study. (2) Methods: Twelve Holstein Frisian cows at mid-lactation were selected to conduct this research. The animals were randomly allocated to two groups (n = 6), and both groups received one of two diets: a low-concentrate (LC) (forage: concentrate 6:4) or a high-concentrate (HC) (forage: concentrate 4:6) diet. Furthermore, an enzyme activity assay, tunnel cell assay, RT-qPCR, western blotting, and an immunofluorescence antibody (IFA) assay were performed to elucidate the effect of an HC diet in the mammary gland of dairy cows. (3) Results: The tunnel cell assay revealed a significant number of apoptotic cells in HC group, and the concentration of Caspase-3, and Caspase-8 was higher in the HC group than in the LC group. NOD1, Rip-2, Caspase-3, Caspase-8, Caspase-9, and Bax mRNA expressions, and NOD1, Caspase-3, Caspase-8, and Bax protein expressions, in the HC group were markedly higher than those in the LC group. Furthermore, Bcl-2 mRNA and protein expressions were markedly decreased in the HC compared to those in the LC group. (4) Conclusions: A HC diet fed to dairy cows incites subacute ruminal acidosis (SARA), which increases the iE-DAP concentration and induces apoptosis in the mammary gland via the NOD1/Caspase-8 pathway.

Efficacy of sodium butyrate in alleviating mammary oxidative stress induced by sub-acute ruminal acidosis in lactating goats.

Sub-acute ruminal acidosis (SARA) [1] is one of the most common problems of dairy animals causing great economical loss due to decreased milk production. Here we determined the antioxidant effect of sodium butyrate (NaB) [2] in experimentally induced SARA and its effects on mammary epithelial tissues of goat. Goats (n = 12) were equally divided into two groups: high-concentrate (HC) as control group fed with HC diet (concentrate: forage = 6:4) whereas HC + NaB as treatment group fed HC diet with NaB at 1% by weight for 24 weeks. Mammary epithelial tissue samples were analyzed for the expression of genes and proteins responsible for oxidative stress as well as biochemical markers of antioxidant activity in the form of Reactive Oxygen Species (ROS). The total antioxidant capacity (T-AOC) of antioxidant enzymes was also calculated. Butyrate induced antioxidant effect by increasing mRNA and protein abundance of antioxidants in mammary gland of HC + NaB group compared to HC group. Likewise, the total antioxidant capacity (T-AOC) was significantly increased and Malondialdehyde (MDA) concentration was decreased in HC + NaB group compared to HC group. It is concluded that oxidative stress in mammary gland of goats induced by high concentrate diet was alleviated by NaB supplementation.

Lipopolysaccharide induces oxidative stress by triggering MAPK and Nrf2 signalling pathways in mammary glands of dairy cows fed a high-concentrate diet.

The goal of current investigations was to reveal the molecular mechanism triggered through feeding a diet with high-concentrate to dairy cows for subacute ruminal acidosis (SARA) induction and to examine the oxidative stress parameters in their mammary epithelial tissue. In an eighteen-weeks feeding trial, 12 Holstein Friesian cows with a standard weight of 455 ±â€¯28 kg were evenly divided into two groups and given either a low-concentrate (LC, forage to concentrate ratio = 6:4) or a high-concentrate (HC, forage to concentrate ratio = 4:6) diet. A remarkable reduction in ruminal pH also increased ruminal lipopolysaccharide (LPS) concentration that was observed in the high-concentrate group of cows at 4 h post-feeding in the morning. Moreover, reduced milk yield was observed in the HC group. The relative mRNA abundance of glutathione peroxidase (GPX) 1 and 3 and superoxide dismutase (SOD) 1 and 2 were down-regulated in high-concentrate fed animals than in the LC, while mRNA was expressed with no change in the of SOD3 among groups. In addition, genes responsible for oxidative stress e.g., ERK, JNK, and p38 were also showed dramatically high mRNA intensity in HC group. The protein concentration of ERK, pERK, pJNK, with pp38, were up-regulated significantly as JNK & p38 showed no big difference. While Nrf2 and pNrf2 were down-regulated considerably in HC group. The total antioxidant capacity (T-AOC) was significantly decreased but of Malondialdehyde (MDA) concentration was raised in HC group than in LC. We thus proposed that higher levels of endogenous LPS may affect the Mitogen-activated protein kinases (MAPK) and nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent antioxidant response.