Effects of source on bioavailability of selenium, antioxidant status, and performance in lactating dairy cows during oxidative stress-inducing conditions

Abstract

In the current study, we used heat stress (HS) as an oxidative stress model to examine the effects of hydroxy-selenomethionine (HMSeBA), an organic selenium source, on selenium's bioavailability, antioxidant status, and performance when fed to dairy cows. Eight mid-lactation Holstein dairy cows (141 ± 27 d in milk, 35.3 ± 2.8 kg of milk/d, parity 2 or 3) were individually housed in environmental chambers and randomly assigned to 1 of 2 treatments: inorganic Se supplementation (sodium selenite; SS; 0.3 mg of Se/kg of dry matter; n = 4) or HMSeBA supplementation (0.3 mg of Se/ kg of dry matter; n = 4). The trial was divided into 3 continuous periods: a covariate period (9 d), a thermal neutral (TN) period (28 d), and a HS period (9 d). During the covariate and TN periods, all cows were housed in TN conditions (20°C, 55% humidity). During HS, all cows were exposed to cyclical HS conditions (32-36°C, 40% humidity). All cows were fed SS during the covariate period, and dietary treatments were implemented during the TN and HS periods. During HS, cows fed HMSeBA had increased Se concentrations in serum and milk, and total Se milk-to-serum concentration ratio compared with SS controls. Superoxide dismutase activity did not differ between Se sources, but we noted a treatment by day interaction in glutathione peroxidase activity as HS progressively reduced it in SS controls, whereas it was maintained in HMSeBA cows. Supplementation with HMSeBA increased total antioxidant capacity and decreased malondialdehyde, hydrogen peroxide, and nitric oxide serum concentrations compared with SS-fed controls. We found no treatment effects on rectal temperature, respiratory rate, or dry matter intake. Supplementing HMSeBA tended to increase milk yield and decrease milk fat percentage. No other milk composition parameters differed between treatments. We observed no treatment effects detected on blood biochemistry, except for a lower alanine aminotransferase activity in HMSeBA-fed cows. These results demonstrate that HMSeBA supplementation decreases some parameters of HS-induced oxidative stress.

Nano-selenium Supplementation Increases Selenoprotein (Sel) Gene Expression Profiles and Milk Selenium Concentration in Lactating Dairy Cows

“…Se exists in the form of selenoproteins (Sels) that play important biological function in dairy cows [13]. The upregulated GPX mRNA expression and GSH-PX activity that we detected indicated that Sel expression of mammary regulated the activities of milk Se-containing enzyme.…”

“…Several studies found that dietary Se has no significant effect on milk yields and components [25,26]. On the contrary, other studies found that Se may result in lower milk protein [27], decreased milk fat [13] and higher milk yields [28]. These results could be due to differences in Se forms and doses/or the composition of the diet.…”

“…Early studies found that after feeding inorganic forms of Se, such as sodium selenite, small amounts of Se were transferred to milk [9]. Dietary organic Se (Se yeast) have also resulted in increased Se concentrations in blood and milk, associated with a reduction in oxidative stress status in cows [10][11][12][13].…”

Supplementation with sodium butyrate improves growth and antioxidant function in dairy calves before weaning

“…Activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and concentration of maleic dialdehyde (MDA) were analyzed using respective commercial kits (Nanjing Jian Cheng Bioengineering Institute, Nanjing, China) as described previously [28]. The inter-assay CVs of SOD, MDA, and GSH-Px were 1.57, 3.28, and 3.21, respectively, and the intraassay CVs of SOD, MDA, and GSH-Px were 3.64 Samples of MR and starter were collected once per week, and the content of DM, crude protein (CP), ash, ether extract (EE), acid detergent ber (ADF), neutral detergent ber (NDF), calcium (Ca), and phosphorus (P) were determined as described in a previous study [29]. The content of protein, fat, lactose, total solids, and non-fat solids of the milk was determined with the mid-infrared procedures using a Milk Oscan Minor machine (MilkoScan Type 78110; Foss Electric, Hillerød, Denmark).…”

Revisiting Oxidative Stress and the Use of Organic Selenium in Dairy Cow Nutrition

“…In ruminant species the assimilation of Se from the diet can be dependent upon rumen conditions that can substantially decrease the availability of mineral forms of Se, in particular sodium selenite [10]. Organic forms of Se do not appear to suffer the same ruminal fate as mineral forms, and as such, would be more available for utilization by dairy cows [11,12]. Therefore, the aim of the current review is to critically analyze existing knowledge on the role of organic Se in dairy cow nutrition with specific emphasis on commercially relevant stresses.…”