Effect Of High Concentrate Diet On Inducing Oxidative Stress In Mammary Glands Of Ruminants And Manipulation By Sodium Butyrate

The mammary gland of dairy cows and goats are the main organ that has directly concerns with the economic status of dairy business.Besides it helps in milk production which is the basic need of young one’s nourishment,human consumption and formation of byproducts used by human being.Mastitis is the inflammation of mammary gland and it is serious issue for the dairy sector globally due to direct losses in terms of expenses on disease control and milk loss.Increased level of ruminal short chain fatty acids(SCFA)after prolong feeding of high concentrate diet lowers the ruminal pH that induces sub-acute ruminal acidosis(SARA).Acidic ruminal pH triggers release of massive amount of endotoxins(lipopolysaccharide,LPS)from gram-negative bacteria in rumen of cow and goat can enter into blood circulation via rumen epithelium.In response,high level of ROS produced and creates oxidative stress that affects mammary gland.The aims of this study were to explore the molecular mechanism of oxidative stress activated by induced SARA in the mammary gland epithelium of lactating cows and goats.Besides,the effect of Sodium butyrate against high concentrate diet SARA induced oxidative stress in lactating goats was evaluated.We also examine the efficacy of Sodium butyrate in the related molecular mechanism.Additionally,the LPS induced oxidative stress in cow’s primary epithelial cells was observed.1.Prolonged Feeding of Concentrate-Rich Rations Provokes Oxidative Stress in mammary Glands of Dairy CowsThe goal of current investigations were to reveal the molecular mechanism triggered through feeding high-concentrate diet in mid-lactation cows for SARA induction and to examine the oxidative stress parameters in their mammary epithelial tissue.In an 18th-week feeding trial,12 Holstein Friesian cows with standard weight of 455 ± 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 was observed in the high-concentrate group of cows at 4 h post-feeding in the morning.The relative mRNA abundance of glutathione peroxidase(GPX)1 and 3 and super oxide dismutase(SOD)1 and 2 were significantly down regulated in high-concentrate fed ration animals than in the LC,while mRNA was expressed with no change in the SOD3 among the groups.In addition,the mRNA expression of genes responsible for oxidative stress like ERK,JNK and p38 were also dramatically increased in HC group.The protein expression of pJNK along with pp38 were dramatically enhanced ERK,pERK,JNK and p38 were significantly up-regulated while Nrf2 and pNrf2 were significantly down-regulated in HC group.The total antioxidant capacity(T-AOC)was significantly decreased while Malondialdehyde(MDA)concentration was significantly increased in HC group than in LC.We thus proposed that higher levels of translocated LPS may affect the MAPK and Nrf2-dependent antioxidant response.2.Lipopolysaccharides Provokes Inflammation and Oxidative Stress in Bovine Mammary Epithelial Cells by Activating MAPK and Nrf2 Signalling PathwaysThis research aims to study the effect of LPS on the oxidative stress in the bovine mammary epithelial cells(BMEC).Improvement in growth and dairy production from milking animals has remained main task for dairy industry.With the aim of getting high yield,the dairy farmers adopt intensive dairy production system in which animals are fed high concentrate diet to boost energy that may lead to SARA and acidosis which ultimately produces LPS.As LPS are the endotoxins a major component of gram negative bacteria produces various conditions such as heat stress,oxidative stress,affects the animal health,performance along with loss of production.For this purpose of study we used BMEC and made two groups,control versus LPS.Cells were exposed to LPS(4000ng/ml)for 6 hrs.The results showed that in LPS group up regulation of pro-inflammatory genes and down regulation of antioxidant genes were significantly found.Collectively,the data demonstrated that LPS group shows effective pro oxidative activity that increased generation of ROS in BMEC and found up regulation of pro inflammatory genes and down regulation of anti-oxidant enzymes by triggering MAPK and Nrf2 signaling Pathways.Finally our research proved that LPS can provokes oxidative stress in BMEC.3.Efficacy of Sodium Butyrate in Alleviating Mammary Oxidative Stress Induced by Subacute Ruminal Acidosis in Lactating GoatsSubacute ruminal acidosis(SARA)is one of the most acute problems of ruminants.It may cause oxidative stress in mammary epithelium of lactating goats,reduce milk production and producing a great economical loss.We first time studied the use of Sodium butyrate(NaB)as an antioxidant in goats exposed to experimentally induced SARA and its effects on mammary epithelial tissues.In current study twelve multiparous mid-lactating Saanen goats were used.And were ruminal cannulated,grouped into two,each consisting six goat.HC(high concentrate)a control group fed with high-concentrate diet(concentrate:forage=6:4)whereas HC+NaB(treatment group)fed high concentrate diet with NaB by weight in a treatment group.Antioxidant activity of NaB,genes responsible for oxidative stress e.g.ERK,JNK and p3 8 and biochemical markers of antioxidant activity in the form of ROS were measured.The total antioxidant capacity(T-AOC)of anti-oxidant enzymes were also were also calculated.The results showed increased anti-oxidant effect in mammary gland of treatment group.The gene expression of p38,ERK and JNK reduced remarkably while SOD1,SOD2,SOD3 and GPX2 were significantly enhanced in treatment group.The protein abundance of ERK,pERK,JNK,pJNK,p38 with pp38 downregulated dramatically while Nrf2 and pNrf2 considerably were upregulated in treatment group.The total antioxidant capacity(T-AOC)was significantly increased and of Malondialdehyde(MDA)concentration was declined extensively in treatment group.Our research determined that oxidative stress in mammary gland induced by high concentrate diet was alleviated by NaB supplementation.