Mammary gene expressions and oxidative indicators in ruminal fluid, blood, milk, and mammary tissue of dairy goats fed a total mixed ration containing piper meal (Piper betle L.)

Abstract

The study evaluated the effect of piper meal which contains flavonoids, essential oils, and phenolic acids on the activity of antioxidant enzymes such as superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT), and as well as oxidative stress indicators such as 1,1-diphenyl-2-picrylhydrazyl-scavenging activity and thiobarbituric acid-reactive substances (TBARS) in the ruminal fluid, mammary tissue, milk, and blood of lactating goats. Fourteen early lactating Saanen goats (body weight, 44 ± 2.51 kg; 14 ± 3 days in milk) were allotted in equal number to two experimental groups, each received one of the two total mixed rations: control (CON) diet (containing 0% piper meal) and CPM diet (CON diet containing 1.3% piper meal per kg dry matter). Compared with goats fed the CON diet, those fed CPM diet had similar 1,1-diphenyl-2-picrylhydrazyl-scavenging, GPx and CAT activity in ruminal fluid, mammary tissue, milk, and blood; however, those samples had increased SOD activity. Dietary CPM diet had a tendency to decrease TBARS production in ruminal fluid, mammary tissue, milk, and plasma by about 2.4, 1.2, 1.1, and 1.4 folds, respectively. Furthermore, alleviated values of TBARS were associated with dwindling mRNA expression of κ light polypeptide gene enhancer in nuclear factor kappa B subunit 1 (NFKB1) but greater expression of SOD1, SOD2, SOD3, and nuclear factor (erythroid-derived 2)-like 2 (NFE2L2) in mammary tissue. Our findings showed that the inclusion of 13.0 g piper meal in per kg diet (CPM) can improve the oxidative status of Saanen goats in early lactation.