Effect of soya bean and fish oil inclusion in diets on milk and plasma enzymes from sheep and goat related to oxidation

Abstract

This study investigated the effects of dietary inclusion of soya bean oil combined with fish oil (SFO) on the activities of a) superoxide dismutase (SOD), glutathione reductase (GR), catalase (CAT) and glutathione transferase (GST) in blood plasma and b) SOD, GR, CAT and lactoperoxidase (LPO) in the milk of sheep and goats. Furthermore, the oxidative stress indicators for measuring total antioxidant activity and free radical scavenging activity [ferric reducing ability of plasma (FRAP) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays] and oxidative stress biomarkers [malondialdehyde (MDA) and protein carbonyl (PC)] were also determined in the blood plasma and milk of the animals. For this purpose, twelve dairy sheep and twelve dairy goats were assigned each to two homogenous subgroups. Treatments in both animal species involved a control diet without added oil and a diet supplemented with 5% soya bean oil and 1% fish oil. The results showed that the inclusion of SFO in the diets of sheep and goats increased significantly the activities of CAT and GR in their blood plasma. The same effect was observed for the activities of GST and FRAP in the blood plasma of goats. Moreover, the fact that the goats had significantly higher average daily PUFA intake (3.62 g/kg BW ) compared to sheep (2.51 g/kg BW ) resulted in an enhancement in the MDA content in their plasma. A significant increase in CAT activity in the milk in both animal species fed with SFO diets was also found. Finally, due to the higher apparent transfer rate of n-3 FA from the diet to the milk in sheep, the PC concentrations were found to be enhanced in their plasma and milk. In conclusion, the impact of dietary SFO supplementation on the oxidative status of body and/or on the milk of small ruminants depends not only on the daily PUFA intake, but also on the amount of n-3 FA that reach their milk.

Assessing the Optimum Level of Supplementation with Camelina Seeds in Ewes’ Diets to Improve Milk Quality

“…In a previous study, supplementing whole sesame seeds also boosted the antioxidant capacity that was measured with ABTS and FRAP assays in goats’ milk [ 47 ]. Moreover, supplementing both ewes and goats with PUFA also resulted in increased levels of CAT and FRAP [ 52 ]. In contrast, an infusion with high linolenic fatty acid in dairy cows, despite resulting in enhanced content of ω3 PUFA in milk, also negatively affected its oxidative stability [ 53 ], while supplementing ALA in vitro, was linked with increased free radical production in prostate cells compared with the supplementation with linoleic acid [ 54 ].…”

Dietary Supplementation of a Live Yeast Product on Dairy Sheep Milk Performance, Oxidative and Immune Status in Peripartum Period

“…Optimizing nutrition requirements by improving rumen efficiency may suppress the concentration of such trigger metabolites and improve the oxidative status. Glutathione reductase (GR) has a central role in the antioxidant defense system since it catalyzes the conversion of oxidized glutathione disulfide to the reduced form of glutathione, which is a critical molecule in resting oxidative stress [56]. It is known that glutathione is extremely important since it acts as substrate or co-substrate in enzymatic reactions (e.g., the glutathione-S-transferase or glutathione-shuttle enzymes), reacts directly with free radicals and lipid peroxides, and protects cells [57].…”

Recent research of feeding practices and the nutrition of lactating dairy goats

“…The dietary level and type of oil added can have effects apart from milk fat concentration and FA composition. One aspect addressed by Tsiplakou et al (2017a) is the effect on conditions relating to oxidation. Alpine crossbred dairy goats at 90 DIM were fed a 50% concentrate diet with or without 2.5% soybean oil and 0.5% fish oil, although it appeared that intake was not ad libitum.…”