Inclusion of soybean and linseed oils in the diet of lactating dairy cows makes the milk fatty acid profile nutritionally healthier for the human diet

Abstract

Fluid milk and its derivatives are important dietary ingredients that contribute to daily nutrient intake of the modern Homo sapiens. To produce milk that is healthier for human consumption, the present study evaluated the effect of adding soybean oil and linseed oil in the diet of lactating cows. The fatty acid profile of milk, milk composition, and the blood parameters of cows were evaluated. Eighteen Holstein cows were distributed in a replicated Latin square design and distributed according to the following treatments: 1) Control (CC): traditional dairy cow diet, without addition of oil; 2) Soybean oil (SO): 2.5% addition of soybean oil to the traditional diet, as a source of omega-6; 3) Linseed oil (LO): 2.5% addition of linseed oil in the diet as a source of omega-3. Milk production was not affected, but oil supplementation decreased feed intake by 1.93 kg/cow/day. The milk fat percentage was significantly lower when cows were supplemented with vegetable oil (3.37, 2.75 and 2.89% for CC, SO and LO, respectively). However, both soybean and linseed oils decreased the concentration of saturated fatty acids (66.89, 56.52 and 56.60 g/100g for CC, SO and LO respectively), increased the amount of unsaturated fatty acids in milk (33.05, 43.39, and 43.35 g/100g for CC, SO and LO respectively) and decreased the ratio between saturated/unsaturated fatty acids (2.12, 1.34, and 1.36 for CC, SO and LO respectively). Furthermore, SO and LO increased significantly the concentration of monounsaturated fatty acids (29.58, 39.55 and 39.47 g/100g for CC, SO and LO respectively), though it did not significantly alter the level of polyunsaturated fatty acids in milk fat (3.57, 3.93 and 3.98 g/100g for CC, SO and LO respectively). Supplementation with LO enhanced the concentration of omega-3 fatty acids on milk (0.32, 0.36, and 1.02 for CC, SO and LO respectively). Blood variables aspartate aminotransferase, gamma glutamyl transferase, urea, albumin, creatinine and total proteins were not altered. On the other hand, total cholesterol, HDL and LDL were greater in the group supplemented with vegetable oils. Supplementation with vegetable oils reduced the dry matter intake of cows, the fat content of milk, and improved saturated/unsaturated fatty acid ratio of milk fat. Compared to the SO treatment, animals fed LO produced milk with greater content of omega-3, and a more desirable omega-6/omega-3 ratio on a human nutrition perspective. Thus, the inclusion of SO and LO in the diet of lactating dairy cows makes the milk fatty acid profile nutritionally healthier for the human consumption.

Effect of cow’s milk with different PUFA n-6: n-3 ratios on performance, serum lipid profile, and blood parameters of grower gilts

“…PUFA content and low n-6/n-3 PUFA ratio are more beneficial to human health, which n-3 and n-6 polyunsaturated fatty acids and their proportions are correlated with human diseases [11].According to [12], the inclusion of canola oil in dairy cow diets can reduce milk SFA and improved omega-3. Results similar were obtained by [13] showed alteration on milk fatty acids profile after supplementing dairy cows with linseed and soybean oil, resulting in improved saturated/unsaturated fatty acid ratio and higher content of omega-3, and a more desirable omega-6/omega-3 ratio.Milk enriched with PUFA showed a reduction in the concentration of LDL in the blood of rats [14], and in gilts supplemented with cow's milk naturally enriched with n-3 and n-6 from 34 days of age until the end of lactation also showed a reduction in LDL for the n-3 and n-6 treatments and improve the performance of weaned piglets [15]. However, we did not find studies evaluating the effects of providing PUFA-enriched milk on the development of pigs, considering the pig as an animal model for humans.…”

“…The linoleic acid and EPA can directly regulate SCD activity at the level of transcription via sterol regulatory element-binding protein 1c (SREBP-1c), but the same does not occur with α-linolenic acid (ALA) [39]. Therefore, the difference in stearic acid found between n-3 and n-6 groups may have been influenced by all these factors, since cow's milk enriched with soy oil had a higher concentration of linoleic acid (2.13, 2.62 and 2.03, control, soybean, and linseed, respectively [13].…”

Histórico, Usos E Importância Econômica Da Linhaça

“…Em estudo recente, OLIVEIRA et al (2021), analisaram a produção e a composição do leite (Tabela 8) e o perfil de AG (Tabela 9) do leite de vacas tratadas com três tipos de ração, sendo elas: ração controle (CC); ração com óleo de soja (OS) com fonte de ômega-6 (adição de 2,5% de óleo à ração controle); e ração com óleo de linhaça (OL) como fonte de ômega-3 (adição de 2,5% de óleo à ração controle).…”

“…Em relação a composição leiteira, percebe-se que os tratamentos OS e OL tiveram diminuição no teor e rendimento de gordura do leite assim como no teor de sólidos totais em comparação ao controle. Segundo os autores este resultado foi em decorrência da silagem utilizada, pois esta continha grande quantidade de grãos o que resultou em menor quantidade de fibras necessárias, já que estas são precursoras da gordura do leite (OLIVEIRA et al, 2021). Apesar da diminuição da gordura e dos sólidos totais, os autores relatam que essa diminuição tem seus prós e contras.…”

Beneficial Effects of High Intensity Interval Training and/or Linseed Oil Supplementation to Limit Obesity-Induced Oxidative Stress in High Fat Diet-Fed Rats

“…Moreover, to counteract the deleterious effects of the Western diet, dietary oils with modified fatty acid profiles have been manufactured to improve fatty acid intake and limit the risk of chronic diseases [26]. LO inclusion in human diets improves the fatty acid profile [27].…”