Foods of Ruminant Origin with Elevated Content of Polyunsaturated Fatty Acids

McDonald, Ian W.; Scott, T. W.

doi:10.1159/000428538

Cited by 77 publications

(41 citation statements)

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“…Feeding encapsulated rapeseed, sunflower, soyabean or cotton seed oil resulted in the proportion of linoleic acid in total fat being between 15 and 20% [72,98,109]. Besides these changes in the proportions of FA, the structure of milk triglycerides can be modified with a decrease in the proportion of C16:0 and an increase in C18:1 esterified unprotected oils increases both cis and trans C18:1 isomers [8] which arise from ruminal metabolism (trans C18:1) and from mammary desaturation of C18:0 produced in the rumen.…”

Section: Linoleic Acidmentioning

confidence: 99%

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Ruminant milk fat plasticity: nutritional control of saturated, polyunsaturated, trans and conjugated fatty acids

et al. 2000

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-After a brief survey of metabolic pathways and nutrient fluxes involved in mammary lipogenesis, this review summarises the known effects of diet on ruminant milk fat composition. Special attention is given to fatty acids that could play a positive role for human health, such as butyric acid, oleic acid, C18 to C22 polyunsaturated fatty acids and conjugated linoleic acid (CLA). The efficiency of the transfer of C18:2, C18:3, C20:5, C22:5 and C22:6, from the duodenum to the milk, is reviewed. The main dietary factors taken into account are the nature of forages, including pasture, and the supplementation of dairy rations with protected or unprotected vegetable or fish oils. Dose-response curves of milk CLA are reviewed for different fat supplements, as well as the non-linear relationship between milk CLA and trans C18:1. The potential of dietary factors to increase the mean CLA content in cow milk fat is about 300% above basal values. There is, however, a need to evaluate how the different feeding strategies could change the other aspects of milk fat quality. ruminant / nutrition / milk / fatty acids / human healthRésumé -Plasticité de la matière grasse du lait de ruminant : contrôle nutritionnel des acides gras saturés, polyinsaturés, trans et conjugués. Après un bref rappel des voies métaboliques et des flux de nutriments qui concourrent à la lipogenèse mammaire, cette revue est consacrée aux principaux effets des facteurs alimentaires sur la composition des lipides du lait de ruminant. Un intérêt particulier est porté aux acides gras qui peuvent avoir des effets positifs sur la santé humaine, tels que les acides butyrique, oléique, linoléique conjugué (CLA) et les acides gras polyinsaturés, de 18 à 22 atomes de carbone. L'efficacité du transfert des C18:2, C18:3, C20:5, C22:5 et C22:6, du duodénum au lait est estimée à partir des données de la bibliographie. Les principaux facteurs alimentaires considérés sont la nature des fourrages, dont l'herbe pâturée, et la supplémentation des rations pour vaches laitières avec des huiles végétales ou de poisson, protégées ou non. L'augmentation potentielle

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Section: Linoleic Acidmentioning

confidence: 99%

“…This occurs when unusual amounts (20% of the diet) of linseed oil coated with formaldehyde-treated proteins are fed [109]. [93] in two experiments and Mansbridge et al [106] increased the proportion of linolenic acid by up to 1.5% of total FA.…”

Section: Linolenic Acidmentioning

confidence: 99%

Ruminant milk fat plasticity: nutritional control of saturated, polyunsaturated, trans and conjugated fatty acids

et al. 2000

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“…The addition to feeds of liquid formalin, a commercial 40% solution of formaldehyde, at a rate of 2% formaldehyde by weight of protein (McDonald and Scott 1977) has been used to protect fat supplements rich in polyunsaturated fatty acids against biohydrogenation by rumen microbes. Feeding ruminally inert fat sources such as calcium salts of fatty acids has been reported to improve fibre digestion (Schauff and Clark 1992), which in turn could increase feed intake.…”

Section: Feed Intake and Digestibilitymentioning

confidence: 99%

“…Compared with cows fed a control diet, cows fed diets of flaxseed oil treated with formaldehyde and resistant to microbial attack produced milk fat containing, as a percentage of total fatty acids, 20% a-linolenic acid (McDonald and Scott 1977) and cows infused with flaxseed oil in the abomasum produced milk fat with 14% a-linolenic acid (Petit et al 2002). In contrast, milk from cows fed no flaxseed product contained usually less than 1% a-linolenic acid (Glasser et al 2008).…”

Section: Milk Fatty Acid Profilementioning

confidence: 99%

Review: Feed intake, milk production and milk composition of dairy cows fed flaxseed

Petit¹

2010

Can. J. Anim. Sci.

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, milk production and milk composition of dairy cows fed flaxseed. Can. J. Anim. Sci. 90: 115Á127. Flaxseed contains approximately 55% of total fatty acids of the oil as a-linolenic acid and is rich in lignans, which are strong antioxidants. Diets rich in omega-3 fatty acids and antioxidants are known to have beneficial effects on human health such as a decrease in the incidence of cancer, cardiovascular diseases, hypertension, and arthritis. Flaxseed could then be an interesting natural feed to consider for changing milk composition. Cyanogenic glycosides (linustatin and neolinustatin) are present in flaxseed, but the concentration of hydrocyanic acid is very low in milk and ruminal fluid of cows fed flaxseed products. In general, feeding up to 15% of the total dry matter as whole flaxseed has a limited effect on dry matter intake. Heat treatments such as micronization and extrusion have no effect on dry matter intake and the effect of formaldehyde treatment on feed intake is unclear. The effects of flaxseed supplementation on milk production of dairy cows in the early stage of lactation have been neutral. Diet supplementation with whole flaxseed has had no effect on milk yield and composition of dairy cows in the mid or late stages of lactation. Physical processing of flaxseed increased milk production although heat treatment did not. Results on the effect of flaxseed processing on overall milk fat concentration have been controversial, but heat and formaldehyde treatments had no effect. Flaxseed supplementation had no effect on milk fat and protein concentrations, and processing of flaxseed had little effect. The extent of change in the concentration of fatty acids in milk is generally proportional to the level of inclusion of flaxseed in the diet. In conclusion, feeding flaxseed does not affect milk production or composition in the large majority of studies, but its long-term effects on health of cows and productivity still need to be determined.

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“…Processing of feed for fat protection may not be acceptable to consumers or governments, as illustrated by the refusal to accept formaldehyde treatment, in spite of extensive experimentation (McDonald & Scott, 1977). The same argument may hold for newer technologies involving the preparation of fatty acyl amides.…”

Section: Limits To Modification Of Ruminant Fatmentioning

confidence: 99%

Targets and procedures for altering ruminant meat and milk lipids

Demeyer

Doreau²

1999

Proc. Nutr. Soc.

217

132

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Beef and dairy products suffer from a negative health image, related to the nature of their lipid fraction. Rumen lipid metabolism involves the presence of saturated lipids in ruminant tissues. Lipolysis, fatty acid biohydrogenation and formation of microbial fatty acids in the rumen and their effects on rumen outflow of fatty acids are discussed. Special emphasis is given to the formation of trans-fatty acids and the possibilities of decreasing biohydrogenation. Small differences in intestinal digestibilities of fatty acids are mentioned, followed by a discussion on transfer of absorbed fatty acids into milk and adipose tissue lipids. The preferential retention of polyunsaturated fatty acids as well as the balance between synthesis and incorporation of fatty acids in tissues is described. Dietary means for the modification of milk fat are listed, with special emphasis on the possibilities for enrichment in polyunsaturated fatty acids and the presence of conjugated linoleic acids. A description of the nature and development of fat depots in beef cattle is followed by a discussion of breed, conformation and feed effects on adipose tissue distribution and fatty acid composition. Special emphasis is given to the very lean Belgian Blue double-muscled breed. The review ends with a consideration of the limits to the modification of ruminant fats, involving considerations of consumer acceptance as well as animal welfare and environmental effects.

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Foods of Ruminant Origin with Elevated Content of Polyunsaturated Fatty Acids

Cited by 77 publications

References 0 publications

Ruminant milk fat plasticity: nutritional control of saturated, polyunsaturated, trans and conjugated fatty acids

Ruminant milk fat plasticity: nutritional control of saturated, polyunsaturated, trans and conjugated fatty acids

Review: Feed intake, milk production and milk composition of dairy cows fed flaxseed

Targets and procedures for altering ruminant meat and milk lipids

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