Potential to Alter the Content and Composition of Milk Fat Through Nutrition

Abstract

Nutritional manipulation of the rumen ecosystem provides a strategy to alter the content and composition of milk fat. Dietary fat supplements affect the content and composition of milk fat. The magnitude of changes is influenced by the degree of protection; as protection increases, the deleterious effects fatty acids on microbial activity decreases, and biohydrogenation of C18 unsaturated fatty acids is reduced. In addition, change is influenced by the transfer of dietary fat into milk, which is related to fatty acid composition, degree of ruminal metabolism, and efficiency of digestion. A cascade of metabolic events involving specific nutrients (e.g., trans fatty acids and cyclopropene acids) occurs that regulates the activity of key enzymes in pathways of endogenous fat synthesis within the mammary gland. When cattle are fed oilseeds (e.g., canola and cotton) with > 75% protection from biohydrogenation, the proportion of saturated to unsaturated fatty acids is changed, and the fat content of milk is increased. Human consumption of dairy products containing elevated proportions of C18 mono- and polyunsaturated fatty acids reduces the content of cholesterol in plasma low density lipoproteins. These fat-modified dairy products are more susceptible to autoxidation, which can be controlled by including vitamin E in the diet of lactating cow. These products also have much less solid fat, which improves spreadability of butter. By protecting different oilseeds from ruminal metabolism, demands for energy can be satisfied while producing milk fat that can be designed for consumer and manufacturing requirements.

Mitigation strategies to reduce enteric methane emissions from dairy cows: Update review

“…Fats are added to dairy cattle diets to increase the energy density of diets, enhance milk yield and modify the fatty acid composition of milk fat (Murphy et al 1995;Ashes et al 1997). Fats have also been shown to depress CH 4 production (Dong et al 1997a;Machmuller and Kreuzer 1999;Dohme et al 2000).…”

“…The major problem associated with excessive fat addition (more than 5-6% of the ration) is that it depresses fiber degradation in the rumen (Dong et al 1997a;Mathison et al 1998), and reduces acetate production and milk fat content (Jenkins et al 1996;Ashes et al 1997). Mathison (1997) observed that digestibility of fiber was reduced with the addition of canola oil, such that the metabolizable energy content of the diet was not different from that of the control barley-based diet.…”

The effect of feeding diets markedly differing in the proportion of grass and maize silages on bovine milk fat composition

“…Diet composition and nutrition of dairy cows have been regarded as the most important factors that have often been utilised. The aim of the optimisation of milk fat composition has been the production of fat with more appropriate technological and/or health properties (Perdrix et al, 1996;Ashes et al, 1997).…”

In vitro Biohydrogenation of Linolenic and Linoleic Acids by Microorganisms of Rumen Fluid

“…All tubes were gassed with CO2, tightly fitted with rubber stopper equipped with a gas release valve, and incubated at 39 ℃ for 0, 3, 6, 9, 24, or 36h. The rotating platform of the incubator (Lab-line, Environ-Melrose Park, IL) was adjusted at 175 turns min 1 -. At the end of each incubation period, tubes were withdrawn and immediately frozen.…”

“…Whereas, only 6.0% DM was lost during the ensilage of wilted silages, distributed as 4.8% DM loss during fermentation and oxidation, 0% in effluent and 1.2% in surface waste (Mayne and Gordon, 1986). Losses of either DM during S fermentation, or soluble components in S effluent, which contains soluble carbohydrates and soluble nitrogenous compounds (McDonald et al, 1991) could have contributed to an increase in the C18:2 and C18:3 concentration of S. The DM content of typical silage effluent varies between 20 and 100 g kg 1 -DM and contains organic N, potassium, 1) The hydrogenation of C18:2 and C18:3 was described according to the equation Pt = x + y e zt -, The appearance of C18:0 was described according to the equation Pt = a + b (1 e -ct -). 2) Means within a row followed by the same letter are not different at a 0.05 level of significance by LSD multiple range test.…”