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The objective of the study was to investigate the effects of oil sources in the diet on milk yield, milk composition, and fatty acid (FA) profiles in mid-lactating dairy cows. Forty-eight Chinese Holstein dairy cows averaging 150 days in milk (DIM) at the start of the experiment (body weight = 596±19 kg; milk yield = 29.7±3.00 kg/d) were used in a completely randomized block design. The animals were assigned into four dietary treatments according to DIM and milk yield, and supplemented with no oil (control), 2% flaxseed oil (FSO), 2% soybean oil (SBO), and 2% oil from extruded soybeans (ESB). The experiment lasted nine weeks including the first week for adaptation. Milk yields, milk compositions (fat, protein, and lactose), and milk FA profiles were measured. Daily milk yield from cows fed with FSO, SBO, and ESB were higher than milk yield of the control cows (27.0, 27.0, and 26.5 vs. 25.4 kg/d). Milk fat percentage of the control cows was greater than those cows fed with oil-supplemented diets. However, increasing dietary fat content resulted with no change in fat-corrected milk yield. The FA profile of milk was changed by fat supplementation. Feeding oil reduced the proportion of both short-chain (C8:0 to C12:0) and medium-chain (C14:0 to C16:1) FAs, and increased the proportion of long-chain (≥C18:0) FAs in milk fat. Cis-9, trans-11 conjugated linoleic acid (CLA) in milk fat was increased from 0.38% for the control to 0.79, 1.51, and 1.56% of fat for the cows supplemented with FSO, SBO, and ESB, respectively. Feeding oils rich in linoleic acid (SBO and ESB) was more effective in enhancing cis-9, trans-11 CLA in milk fat than oils containing linolenic acid (FSO). There was a linear relationship between transvaccenic acid and cis-9, trans-11 CLA content in milk. Overall, feeding the FSO, SBO, and ESB diets increased monounsaturated and polyunsaturated fatty acids and decreased the saturated fatty acid in milk fat. [ABSTRACT FROM AUTHOR]

Yellow horn ( Xanthoceras sorbifolia ) is a woody deciduous shrub or small tree native to northwest China that has been widely planted for bioactive oil production and ecological restoration. Ten years of field experiments indicate that yellow horn is well adapted to desert and xeric habitats of Liaoning, Inner Mongolia, and Xinjiang, China, and is an excellent prospect for alternative agricultural production and revegetation of arid regions as well as production of bioactive oils. In Horqin Sandy Lands, 7–11 year old unselected mixed lines averaged 152.30 kg/ha seeds, and selected pure lines averaged 1944.89 kg/ha, with average seed oil content of 25% and 34%, respectively. Seeds contain about 90% unsaturated fatty acids (C18:1, C18:2, C18:3, C20:1, C20:2, C20:5, C22:1 and C24:1) and 10% fatty acids comprised primarily of C16:0 and C18:0. Yellow horn seed oils are very high quality with low acid levels of 0.52 mg KOH/g (73% of which is unsaturated C18). Interestingly, the concentration of C24:1, an important bioactive compound is over 2%. Yellow horn is a unique plant species with potentially strong value for both ecological restoration of arid habitats and control of desertification, as well as an important and sustainable producer of high quality bioactive oils, which are used for food, healthy diets, and medical products. [ABSTRACT FROM AUTHOR]