Synthesis of milk fat from β-hydroxybutyrate and acetate by ruminant mammary tissue in vitro

McCarthy, S.; Smith, Graham

doi:10.1016/0005-2760(72)90031-8

Cited by 23 publications

(9 citation statements)

References 27 publications

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“…The increase in the concentrations of long-chain fatty acids with over 18 carbons can be attributed to the increase in the fatty acid intake of cows fed the CS and SO diets when compared with diet C. However, according McCarthy et al (1972), butyric acid is a short-chain fatty acid that undergoes few alterations in its concentrations in milk due to dietary changes.…”

Section: Discussionmentioning

confidence: 99%

Fatty acid profile and composition of milk protein fraction in dairy cows fed long-chain unsaturated fatty acids during the transition period

et al. 2013

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-The objective of this study was to evaluate the utilization of different sources of unsaturated long-chain fatty acids in diets for dairy cows during the transition period and early lactation on the milk fatty acid profile and composition of the protein fraction. Thirty-six Holstein cows were divided into three groups, fed the following diets: control (C); soybean oil (SO); and calcium salts of long-chain unsaturated fatty acids (CS). The milk samples utilized for analysis were obtained weekly from parturition to twelve weeks of lactation; each one of the samples originated from two daily milkings. Milk composition and total nitrogen, non-protein nitrogen and non-casein nitrogen levels were analyzed. The cows receiving the diet with calcium salts had lower concentrations of non-protein nitrogen (%CP) in milk compared with the animals fed the diet with soybean oil. There was a decrease in concentration of medium-chain fatty acids C12-C16, and a concomitant increase in concentrations of long-chain fatty acids >C18 in milk fat for the animals fed the diets CS and SO when compared with diet C. Soybean oil and CS diets increased milk-fat concentrations of the acids C18: 1 trans-11, C18: 2 cis-9, trans-11 and C18: 2 trans-10 cis-12 in relation to diet C. The utilization of sources of long-chain fatty acids in the diet of dairy cows increases the biological value of milk in early lactation due to higher concentrations of specific fatty acids such as CLA C18: 2 cis-9, trans-11.

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Section: Discussionmentioning

confidence: 99%

Fatty acid profile and composition of milk protein fraction in dairy cows fed long-chain unsaturated fatty acids during the transition period

et al. 2013

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“…Our models showed that the effects of C2 on milk fat secretion were lower than those of C4. This finding could be explained by the specific role of b-hydroxybutyrate (synthesized from C4) as a precursor to initiate de novo FA elongation (Palmquist et al, 1969;McCarthy and Smith, 1972). However, the effect of C2 on MFC could be slightly underestimated because C2 significantly increased MY (dilution effect), unlike C4.…”

Section: Discussionmentioning

confidence: 99%

Response of milk fat concentration and yield to nutrient supply in dairy cows

Maxin

Rulquin

Glasser

2011

Animal

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Dietary changes alter dairy cow milk fat concentration (MFC) and yield (MFY) through modifications in the supply of nutrients, which act as precursors or inhibitors of mammary fat synthesis. The current models used to formulate dairy cow diets cannot predict changes in milk fat. The knowledge of the effects of the nutrients on milk fat would help to progress toward this prediction. To this end, we quantified and compared the milk fat responses to variations in the supply of seven nutrients derived from digestion: volatile fatty acids, glucose, proteins, long-chain fatty acids (LCFA) and t10,c12-conjugated linoleic acid (CLA). A database was compiled from studies involving digestive infusions of these nutrients in dairy cows. It included 147 comparisons between a nutrient infusion and a control treatment. The nutrient infusions were limited to the range of physiological variations to mimic nutrient changes after dietary modifications. We established models for the response of MFC, MFY and milk fatty acid (FA) composition to the supply of each nutrient. MFC and MFY responses to the nutrients were significant and linear, except for the MFC response to glucose that was curvilinear. The nutrients differed in their effects on MFC and MFY: acetate, butyrate and LCFA increased MFC and MFY, whereas propionate, glucose and t10,c12-CLA decreased them. Protein infusions increased MFY and decreased MFC because of an increase in milk yield. The effects of numerous interfering factors related to animals, diets or experimental conditions were tested on the residuals of the response models. The responses of milk FA percentages are also provided. When adjusted to the in vivo variations in the nutrients observed after dietary changes, the effects of the different nutrients were moderate. Finally, this study showed that several of these nutrients could contribute to the changes in milk fat production and composition observed after dietary changes. This is a first step toward predicting milk fat response to changes in nutrient supply.Keywords: milk fat, dairy cow, meta-analysis, nutrients ImplicationsFluctuations in the milk fat market are driving demands from farmers for ways to control milk fat production and composition in dairy cows. The current models used to estimate dairy cow requirements and formulate diets cannot predict changes in milk fat. These models are based on energy and protein intake and do not consider the pattern of individual nutrients derived from digestion. Using published infusion studies, this meta-analysis quantifies and compares the effects on milk fat secretion of several nutrients derived from digestion. It is a first step toward a model to estimate variations in milk fat based on variations in nutrient supply.

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“…The composition and content of ruminant milk fat is strongly influenced by physiological, seasonal and nutritional factors (Palmquist et al 1993). Acetate has been identified as the major precursor of lipogenesis and can be incorporated into fatty acids (McCarthy & Smith 1972). Butyrate can also be incorporated into milk fatty acids after being converted to D-3-hydroxybutyrate during absorption through the rumen epithelium (McCarthy & Smith 1972;Månsson 2008).…”

Section: Introductionmentioning

confidence: 99%

“…Acetate has been identified as the major precursor of lipogenesis and can be incorporated into fatty acids (McCarthy & Smith 1972). Butyrate can also be incorporated into milk fatty acids after being converted to D-3-hydroxybutyrate during absorption through the rumen epithelium (McCarthy & Smith 1972;Månsson 2008). Some studies provided evidence that SCFAs may play an important role in the regulation of milk fat metabolism in mammary epithelial cells (MECs) (Yonezawa et al 2004;Jacobs et al 2013).…”

Section: Introductionmentioning

confidence: 99%

Effect of short‐chain fatty acids on triacylglycerol accumulation, lipid droplet formation and lipogenic gene expression in goat mammary epithelial cells

Sun

Luo

Zhu

et al. 2015

Animal Science Journal

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Short-chain fatty acids (SCFAs) are the major energy sources for ruminants and are known to regulate various physiological functions in other species. However, their roles in ruminant milk fat metabolism are still unclear. In this study, goat mammary gland epithelial cells (GMECs) were treated with 3 mmol/L acetate, propionate or butyrate for 24 h to assess their effects on lipogenesis. Data revealed that the content of triacylglycerol (TAG) and lipid droplet formation were significantly stimulated by propionate and butyrate. The expression of FABP3, SCD1, PPARG, SREBP1, DGAT1, AGPAT6 and ADRP were upregulated by propionate and butyrate treatment. In contrast, the messenger RNA (mRNA) expression of FASN and LXRα was not affected by propionate, but reduced by butyrate. Acetate had no obvious effect on the content of TAG and lipid droplets but increased the mRNA expression of SCD1 and FABP3 in GMECs. Additionally, it was observed that propionate significantly increased the relative content of mono-unsaturated fatty acids (C18:1 and C16:1) at the expense of decreased saturated fatty acids (C16:0 and C18:0). Butyrate and acetate had no significant effect on fatty acid composition. Overall, the results from this work help enhance our understanding of the regulatory role of SCFAs on goat mammary cell lipid metabolism.

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Synthesis of milk fat from β-hydroxybutyrate and acetate by ruminant mammary tissue in vitro

Cited by 23 publications

References 27 publications

Fatty acid profile and composition of milk protein fraction in dairy cows fed long-chain unsaturated fatty acids during the transition period

Fatty acid profile and composition of milk protein fraction in dairy cows fed long-chain unsaturated fatty acids during the transition period

Response of milk fat concentration and yield to nutrient supply in dairy cows

Effect of short‐chain fatty acids on triacylglycerol accumulation, lipid droplet formation and lipogenic gene expression in goat mammary epithelial cells

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