Influence of lipid supplementation on milk components and fatty acid profile

Abstract

-The objective of this study was to evaluate the effects of different lipid sources in diets for lactating cows on milk yield and composition, conjugated linoleic acid (CLA) content, and fatty acid profile in the milk fat. Five primiparous Holstein cows were distributed in a 5 × 5 Latin square design. Treatments were: control (no lipid addition) and four other diets containing different lipids sources -ground raw soybean, cottonseed, soybean oil, and calcium salts of soybean fatty acids (CSSFA). The greater milk yield (kg/day) and milk lactose (g/kg) and solids non-fat (g/kg) contents were obtained with the animals fed diets with CSSFA. Regarding the fatty acid profile in the milk fat, the diets with CSSFA and ground raw soybeans produced the greatest concentrations of polyunsaturated fatty acids and C 18:2 . Supplementation with CSSFA provided a greater production (g/day) of CLA, resulting in almost twice the values shown by the other treatments. The use of different lipid sources does not affect the milk total solids (protein, fat, and lactose) and CSSFA has a positive influence on the fatty acid profile of the milk fat and amount of CLA produced. Additionally, milk yield is not affected by this supplement.Key Words: biohydrogenation, dairy production, fatty acids, supplementation Revista Brasileira de Zootecnia

Association of housing and management practices with milk yield, milk composition, and fatty acid profile, predicted using Fourier transform mid-infrared spectroscopy, in farms with automated milking systems

“…This indicates a dilution effect, because as milk yield increases, the concentrations, on a milk basis (g/100 g of milk), of fat, mixed FA, and de novo FA decrease. The opposite occurs when milk production decreases (Harvatine and Allen, 2005;Machado et al, 2017). Strong positive correlations were also detected among yield (kg/d) of milk, fat, de novo FA, mixed FA, and preformed FA (Table 4).…”

“…Strong positive correlations were also detected among yield (kg/d) of milk, fat, de novo FA, mixed FA, and preformed FA (Table 4). Thus, when milk yield increases, the yield (kg/d) of all these milk components also increases (Harvatine and Allen, 2005;Machado et al, 2017). This emphasizes that we must be careful when evaluating only the bulk tank milk FA concentration (g/100 g of milk) because variations in FA content may be related to other factors that lead to changes in milk yield, and consequently change FA concentration.…”