Scientists who conducted a dietary study in horses found that supplementation with flaxseed oil is a healthier option than soybean oil.
The researchers who carried out the study in Poland noted that, in horse nutrition, particular focus is placed on the quality of the fat used.
Soybean, rapeseed or maize oil are commonly used, while others opt for fish oil or flaxseed oil.
Iwona Sembratowicz and her colleagues at the University of Life Sciences said flaxseed oil has long been used in animal feeding and human nutrition because of its beneficial biologically active substances. It has high levels of omega-3 polyunsaturated fatty acids. It also has a highly favourable ratio of omega-6 to omega-3.
Despite the advantages of flaxseed oil in the diet of humans and animals, excess intake of polyunsaturated fatty acids, especially omega-3 acids, which are particularly susceptible to oxidation, may risk increasing oxidation reactions in the body. This, they said, can result in antioxidant imbalance and the onset of oxidative stress.
That said, numerous experiments have confirmed the benefits of flaxseed oil in reducing oxidative stress
In the work published in the journal Animals, Sembratowicz and her colleagues postulated that the inclusion of flaxseed oil in the diet of horses may enhance antioxidant defence mechanisms and positively influence blood biomarkers.
They devised a dietary experiment in horses to assess the effect of replacing soybean oil with flaxseed oil on the haematological and biochemical parameters of their blood, including the redox status (the balance between oxidants and antioxidants).
The study involved 40 healthy horses, comprising 20 mares and 20 stallions of the Malopolski breed.
They were divided equally into two groups that were similar in terms of age, sex, and body weight, which averaged about 530kg.
They were housed individually and did only light work daily.
All received standard rations twice a day comprising meadow hay and crushed oats. They also received a mineral and vitamin supplement with their morning feed.
The only factor differentiating the groups was the kind of oil added to their base diet. The control group received soybean oil at the daily rate of 25 millilitres per 100kg of bodyweight, while the horses in the experimental group received flaxseed oil at the same rate.
The oil was given after the horses’ morning feed, orally with a syringe by an individual who cared for the horses on a daily basis.
After 60 days of oil supplementation, a blood sample for analysis was collected from each horse before their morning feed.
The study team found that the horses fed flaxseed oil, when compared to the soybean group, had better lipid profiles, improved haematological parameters and enhanced antioxidant defence mechanisms, thus reducing the severity of oxidative stress.
The flaxseed group had significantly lower plasma levels of glucose, low-density lipoprotein cholesterol, total cholesterol/high-density lipoprotein (HDL) ratio and triacylglycerols, as well as the activities of alanine aminotransferase and alkaline phosphatase.
The inclusion of flaxseed oil also contributed to an increase in antioxidant indices: creatinine, vitamin C, copper, and zinc contents, and also superoxide dismutase and catalase activities.
Flaxseed oil also caused an elevation in red blood cell indicators, lymphocyte count and lysozymes.
The results suggest that substituting soybean oil with flaxseed oil in the diet of horses is beneficial for their health status, they said.
Discussing their findings, the researchers said most of the blood and biochemical parameters determined in the study were within the wide range of reference values specified for horses, which indicated that the horses used in the study were in good health and condition.
The beneficial effect of flaxseed oil on lipid metabolism is linked to the presence of alpha-linolenic acid, which belongs to the family of omega-3 polyunsaturated fatty acids, they said.
The study team comprised Sembratowicz, Grzegorz Zięba Ewelina Cholewinska and Anna Czech.
Sembratowicz, I.; Zięba, G.; Cholewinska, E.; Czech, A. Effect of Dietary Flaxseed Oil Supplementation on the Redox Status, Haematological and Biochemical Parameters of Horses’ Blood. Animals 2020, 10, 2244.