Transport of fatty acids within plasma lipoproteins in lactating and non-lactating cows fed on fish oil and hydrogenated palm oil.

The aim of this study was to elucidate the effect of dietary fish oil (FO) and a blend of FO and hydrogenated palm oil (FOPO) on transport of fatty acids (FA) within plasma lipoproteins in lactating and non-lactating cows. Two trials were conducted (one with lactating and another with non-lactating dairy cows) in two 3 × 3 Latin squares that included three periods of 21 days. Dietary treatments for lactating cows consisted of a basal diet (Control; no fat supplement), and fat-supplemented diets containing FO (500 g/day/cow) and FOPO (250 FO + 250 g/day/cow hydrogenated palm oil). For non-lactating cows, dietary treatments consisted of a basal diet (Control; no fat supplement), and fat-supplemented diets containing FO (170 g/day/cow) and FOPO (85 FO + 85 hydrogenated palm oil g/day/cow). In lactating cows, compared with control and FOPO, FO increased C16:0, C18:3 cis-9, 12, 15, C18:2 cis-9, trans-11 and total saturated and polyunsaturated FA in plasma and increased C16:0, C18:2 cis-9, trans-11, total polyunsaturated and total polyunsaturated n-6 in high-density lipoprotein (HDL), whereas in non-lactating cows, compared with control and FOPO, FO increased C16:0, C18:1 trans-11, C18:2 trans-9, 12, C18:2 cis-9, trans-11, C20:5 n-3 and total saturated and polyunsaturated FA in plasma; C16:0, C18:1 trans-11, C18:1 cis-9, C18:2 trans-9, 12, C20:5 n-3 and total monounsaturated FA in HDL; and C18:1 trans-6-8, C18:1 trans-9, C18:1 trans-10, C18:1 trans-11, C18:3 cis-9, 12, 15 and C20:5 n-3 in low-density lipoprotein (LDL). FO increased C20:5 n-3 in plasma and lipoproteins in non-lactating cows and increased C18:3 cis-9, 12, 15 in plasma (in lactating cows) and LDL (in non-lactating cows). We concluded from results of this study that in bovine plasma, the LDL fraction appears to be the main lipoprotein transporting C18:1 trans isomers and is more responsive than other lipoprotein fractions to variation in supply of dietary lipids.

Short communication: Chemical composition, fatty acid composition, and sensory characteristics of Chanco cheese from dairy cows supplemented with soybean and hydrogenated vegetable oils.

Lipid supplements can be used to alter fatty acid (FA) profiles of dairy products. For Chanco cheese, however, little information is available concerning effects of lipid supplements on sensorial properties. The objective of this study was to examine effects of supplementation of dairy cow diets with soybean (SO) and hydrogenated vegetable (HVO) oils on chemical and FA composition of milk and cheese and sensory characteristics of cheese. Nine multiparous Holstein cows averaging 169±24d in milk at the beginning of the study were used in a replicated (n=3) 3×3 Latin square design that included 3 periods of 21d. All cows received a basal diet formulated with a 56:44 forage:concentrate ratio. Dietary treatments consisted of the basal diet (control; no fat supplement), and the basal diet supplemented with SO (unrefined oil; 500g/d per cow) and HVO (manufactured from palm oil; 500g/d per cow). Milk fat yield was lower with HVO compared with control and SO. Cheese chemical composition and sensory profile were not affected by dietary treatment. Vaccenic (C18:1 trans-11) and oleic (C18:1 cis-9) acids were higher for SO than for control and HVO. Compared with control and HVO, SO decreased saturated FA and increased monounsaturated FA. The thrombogenic index of milk and cheese produced when cows were fed SO was lower than when cows were fed on control and HVO. The outcome of this study showed that, compared with control and HVO, supplementing dairy cow diets with SO improves milk and cheese FA profile without detrimental effects on the chemical composition of milk and cheese and the sensory characteristics of cheese.