Trans and conjugated fatty acids in milk from cows and goats consuming pasture or receiving vegetable oils or seeds (original) (raw)
Related papers
Animal Science, 2006
It is well established that plant oils reduce milk saturated fatty acid content and enhance concentrations of conjugated linoleic acid (CLA) and trans C 18:1 in milk fat, but there is increasing evidence to suggest that milk fat CLA responses are often transient and decline over time. It is probable that time dependent adaptations in ruminal biohydrogenation and changes in milk fatty acid composition to lipid supplements are, at least in part, related to the composition of the basal diet. To test this hypothesis, 18 Holstein cows were used in a continuous randomized block design to examine changes in milk fatty acid composition over time in response to plant oils included in diets of variable composition. Cows were randomly allocated to one of three basal diets containing (g/kg dry matter (DM)) maize silage (267) and concentrates (733) (diet C); maize silage (332), grass hay (148) and concentrates (520) (diet M), or grass hay (642) and concentrates (358) (diet H). Basal rations were offered for 21 days, after which diets were supplemented with 50 g sunflower per kg DM (diets C-S and M-S) or 50 g linseed oil per kg DM (diet H-L). Oils were included in all rations incrementally over a five day period (days 0 -4), and responses to 50 g/kg DM of the respective oils were evaluated for 17 days (days 4 to 20). Milk fatty acid composition was intensively monitored from days 2 2 to 20. In contrast to the H-L diet, both C-S and M-S treatments decreased ( P , 0·05) DM intake, milk fat content and yield, while the C-S diet also reduced ( P , 0·05) milk yield. Milk fat cis-9, trans-11 CLA and trans-11 C 18:1 contents were enhanced on the C-S and M-S treatments but the increases were transient reaching the highest concentrations between days 4 and 6 (cis-9, trans-11 CLA: 1·94 and 2·18 g per 100 g total fatty acids; trans-11 C 18:1 : 4·88 and 6·23 g per 100 g total fatty acids, respectively) but declined thereafter. In marked contrast, concentrations of cis-9, trans-11 CLA and trans-11 C 18:1 in milk from the H-L diet increased gradually over time, responses that were maintained until the end of the experiment (2·89 and 7·49 g per 100 g total fatty acids, respectively). Decreases in milk fat cis-9, trans-11 CLA and trans-11 C 18:1 after day 6 on the M-S and C-S diets were associated with concomitant increases in milk fat trans-10 C 18:1 content reaching 7·22 and 18·62 g per 100 g total fatty acids on day 18, respectively, whereas concentrations of trans-10 C 18:1 in milk on the H-L diet remained low throughout the experiment (0·70 g per 100 g total fatty acids on day 18). Furthermore, milk fat trans-11, cis-13 CLA, trans-11, trans-13 CLA and trans-12, trans-14 CLA contents were all enhanced on the H-L diet, while the M-S and C-S diets increased trans-8, cis-10 CLA, trans-10, cis-12 CLA and trans-9, cis-11 CLA concentrations. Across all diets, decreases in milk fat content were associated with increases in milk trans-10 C 18:1 , trans-10, cis-12 and trans-9, cis-11 CLA concentrations (r 2 ¼ 0·93, 0·88 and 0·89, respectively). In conclusion, the relative abundance of trans C 18:1 and CLA isomers in milk fat were dependent on the composition of the basal diet, type of plant oil and duration of lipid supplementation, highlighting the challenges in developing nutritional strategies for the production of milk highly enriched with CLA over an extended period of time.
Italian Journal of Animal Science, 2010
The recent literature dealing with the effect of the diet on the quality of milk and meat fat is reviewed. Some aspects of the rumen metabolism of lipids are dealt with: lipolysis, bio-hydrogenation, synthesis of microbial fatty acids and inhibition mechanisms on fermentation. Firstly, the influence of forage is considered. Pasture is the best forage, better if high hill pasture, as compared to hay and silage: short chain fatty acids (SCFA) (shorter than C10) are increased, medium chain fatty acids (MCFA) (C12 through C16) are decreased, oleic (OA), linoleic (LA) and linolenic (LNA) acids are increased and so are the conjugated linoleic acid pool of isomers (CLA) and n-3 polyunsaturated fatty acids (n-3 PUFA). Secondly, the energy supplementation of diets with fats is looked at. Animal fats depress milk yield and SCFA, while OA is increased because of the enhanced activity of mammary ∆ 9 desaturase. Fish oil depresses milk yield as well, but promotes CLA and n-3 PUFA. If animal fats are protected against rumen bacteria, milk yield and milk fat depression are avoided. Vegetable fats are richer in unsaturated fatty acids (UFA), thus more susceptible to the rumen bio-hydrogenation. As calcium soaps or inside whole seeds, plant fats are protected and CLA is increased. CLA is an important component of fat. In ruminants it comes from the desaturation of vaccenic acid (VA) both in rumen and udder; and the yield of VA depends on the diet quality. In conclusion, simple directions are given on how to improve the quality of animal fat by dietary means, without affecting yield.
Animal Feed Science and Technology, 2005
Milk fat secretion and profiles of conjugated linoleic acids (CLA) and trans-18:1 isomers in milk fat due to a ruminal or duodenal supply of fish oil (FO; EPA = 22% of total fatty acids, DHA = 7%) were evaluated using six lactating Holstein cows with cannulas in their rumen and duodenum. Cows were fed a control diet based on corn silage (66% of DM), or the control plus 300 mL FO/d into the rumen (FO-R) or duodenum (FO-D) for 4 weeks in a replicated 3 × 3 Latin square design. Dry matter intake was higher with the control (19.8 kg/d), intermediate with FO-D (18.0 kg/d), and lower with FO-R (16.2 kg/d). Yield of milk (22.7 kg/d), lactose (1.09 kg/d), or crude protein (0.70 kg/d) was not affected by treatments. Content of crude protein, true protein, and casein was lower in response to FO-R compared with the control. Despite similar jugular concentration compared with the control, jugular-mammary venous difference for -OH-butyrate was 54% lower with FO-R or FO-D. Milk fat content and yield were lowest with FO-R (25 g/kg, 567 g/d) compared with FO-D (32 g/kg, 737 g/d) or the control (35 g/kg, 783 g/d). Percentage of trans5-, trans6 + 7 + 8-, trans9-, trans10-, trans11-, Abbreviations: CLA, conjugated linoleic acid; EPA, eicosapentaenoic acid, 20:5n-3; DPA, docosapentaenoic acid, 22:5n-3; DHA, docosahexaenoic acid, 22:6n-3; VA, vaccenic acid (trans11-18:1); 9/11CLA, cis9,trans11isomer of CLA; 10/12CLA, trans10,cis12-isomer of CLA , and trans13 + 14-18:1 in milk fat was greater due to FO-R (0.05, 0.44, 0.48, 1.8, 9.2, 0.70, and 0.82%, respectively) compared with the control or FO-D (0.02, 0.22, 0.19, 0.27, 1.1, 0.35, and 0.40%). Although 18:0 and cis9-18:1 percentage was markedly lower in response to FO-R, percentage of cis11-, cis13-, and cis15-18:1 was greater compared with the control or FO-D. Cis9,trans11-CLA (87-95% of total CLA) averaged 3.2% in response to FO-R compared with 0.51% for control or FO-D. Trans10,cis12-18:2 was not detected. Among non-conjugated 18:2 isomers, cis9,cis12-18:2 was lower but cis9,trans13-, trans9,cis12-, and trans11,cis15-18:2 greater when FO-R was compared with the control or FO-D. There was high correlation (r = 0.94-0.99) among data obtained by GLC versus HPLC for most trans-18:1 isomers and cis9,trans11-18:2, suggesting GLC alone with our chromatographic conditions provided adequate separation of isomers. Milk 20:5n-3 (EPA) and 22:6n-3 (DHA) were 0.08 and 0.04% with the control, increased to 0.36 and 0.17% with FO-R, and were 1.47 and 0.47% with FO-D. Data indicate, ruminal supply of FO led to hydrogenation of EPA and DHA and enhanced percentage of various trans-18:1, cis-18:1, non-conjugated 18:2, and cis9,trans11-18:2 in milk fat. Combined increases in trans-18:1 along with reduced availability of 18:0 for endogenous synthesis of cis9-18:1 may play a key role in reduced milk fat synthesis in cows fed fish oil.
Dietary Influences on Bovine Milk cis-9,trans-11Conjugated Linoleic Acid Content
Journal of Food Science, 1997
The effects of grass dry matter (DM) allowance and dietary supplements of full fat rapeseeds on levels of cis-9,trans-11 octadecadienoic (CLA) acid in bovine milk were investigated. Grass allowance of 16 kg/(cow*day) resulted in reduced (p<0.05) milk fat CLA levels (3.91 mg CLA/g fat) compared to 20 kg/(cow*day) after 19 wk treatment. CLA levels increased in milk fat from cows on a high-rapeseed-supplemented diet (p<0.001) (1650 g/(cow*day) full fat rapeseed) compared to the control (pasture) and low rapeseed (p<0.01) (825 g/(cow*day) full fat rapeseed) supplemented diets. The variation in milk fat CLA levels among individual cows over both trials was 1.5–16 mg/g.
Journal of Animal and Feed Sciences
Sixteen lactating Sarda ewes were fed 4 diets differing in the forage/concentrate ratio (2 diets 75/25, 2 diets 60/40, DM) and in soyabean oil supplementation (2 diets with 100 g/head/d oil, 2 diets with no oil), in a 4x4 Latin square design. The inclusion of soyabean oil in the diet resulted in a signifi cant increase of both rumenic acid (cis 9 trans, 11 CLA) and vaccenic acid (trans 11 C 18:1) in milk fat, with higher increases with the 2 high forage diets. The 2 low forage diets allowed increases of trans 10 C 18:1 and of trans 10, cis 12 CLA, probably due to a shift of rumen biohydrogenation of linoleic acid.
Influence of breed on bovine milk cis-9, trans-11-conjugated linoleic acid content
Livestock Production Science, 1999
The influence of animal breed on the profile of fatty acids in milk and particularly on the concentration of cis-9, trans-11 octadecadienoic acid, a conjugated lineoleic acid (CLA) was investigated using four breeds of cows, Irish Holstein / Friesian (IH, n 5 23), Dutch Holstein / Friesian (DH, n 5 22), Montbeliardes (MB, n 5 29) and Normandes (NM, n 5 27), on pasture. All cows were grazed together in one group. Milk fat CLA concentration from MB were significantly higher (P , 0.05) than from DH at one of the two sampling times, while the CLA content of milk fat from NM, IH and DH was not significantly different at either sampling time. Milk fat CLA concentrations between the four breeds ranged from 14.7 to 18.6 mg / g fat, while the variation in milk fat CLA between individual cows within the four breeds ranged from 4.8 to 35.6 mg / g fat. There were significant correlations between milk fat CLA concentrations of individual cows within NM (P , 0.001), MB (P , 0.001) and IH (P , 0.001) and the correlation was close to being significant for DH cows (P 5 0.076) at two sampling dates. In terms of total fatty acid profiles, DH had higher (P , 0.05) C concentrations than the other breeds. The IH had a 16:0 16:0 18:0 18:1 Elsevier Science B. V. All rights reserved.
Distribution of conjugated linoleic acid (CLA) isomers and other fatty acids in polar and neutral fractions of milk from cows fed different lipid supplements ¤ Distribución de isómeros de ácido linoléico conjugado (CLA) y ácidos grasos en las fracciones neutra y polar de la leche de vacas alimentadas con diferentes suplementos lipídicos Distribuição de isômeros do acido linoleico conjugado (CLA) e outros ácidos graxos nas frações polares e neutras no leite de vacas alimentadas com diferentes suplementos lipídicos Summary Background: milk fatty acid composition has become very important for consumers due to the positive relationship that has been found between some fatty acids and human health. In recent years, content and fatty acid composition in the different fractions of milk lipids has also become important due to reported potential technological and sensory implications. Objective: the aim of this study was to evaluate the effect of dietary supplementation with several lipid supplements on the proportion of neutral (triglycerides) and polar lipids (phospholipids) of milk fat, alterations of the fatty acid composition and Conjugated Linolenic Acid isomers (CLA) of total milk lipids. Methods: 18 first lactation German Holstein cows were assigned to three dietary treatments for 10 weeks as follows: Rumen-stable fractionated palm fat, linseed oil plus algae, and sunflower oil plus algae. Results: dietary polyunsaturated fat supplements increased the proportion of phospholipids and decreased triglycerides in milk fat compared to Rumen-stable fractionated palm fat. Long chain polyunsaturated fatty acids were preferentially deposited into phospholipids. Diet effect was more pronounced in triglycerides than in phospholipids. Plant oil/algae supplemented diets induced lower proportions of total saturated fatty acids and higher proportions of total unsaturated fatty acids in triglycerides. Conclusions: linseed oil plus algae feeding generated the best results in reference to fatty acids related to human health. Sunflower oil plus algae caused accumulation of CLAtrans-10,