scholarly journals Fatty acids profile of milk from cows fed different maize silage levels and extruded soybeans

2012 ◽  
Vol 13 (1) ◽  
pp. 192-203 ◽  
Author(s):  
Marcelli Antenor Oliveira ◽  
Ronaldo Braga Reis ◽  
Márcio Machado Ladeira ◽  
Cláudio Vaz Di Mambro Ribeiro ◽  
Leandro Sâmia Lopes ◽  
...  

The objective of this study was to evaluate the effects of two levels of maize silage and extruded soybeans supplementation on fatty acid profile in milk fat of dairy cows. Eight Holstein cows were distributed in a double 4x4 Latin Square design with a factorial arrangement. The treatment groups were: high maize silage and low lipid, high maize silage and high lipid, low maize silage and low lipid and low maize silage and high lipid. The experimental periods lasted 21 days. Milk samples were collected on days 18 and 19 of each experimental period. The increase of lipid contents in high and low maize silage diets decreased short chain fatty acids concentrations (C4:0 - C12:0). The conjugated linoleic acid content (cis-9 trans-11 C18:2) increased from 3.72 to 4.85, and 4.6 to 5.89mg/g, when extruded soybeans was used in high and low level of corn silage, respectively. The increase in dietary lipids content resulted in higher trans-11 C18:1 fatty acid concentration. Fatty acid trans-10 C18:1 tended to increase with the elevation of the lipids content in the diet. There was significant correlation between trans-10, cis-12 C18:2 and milk fat percentage. The extruded soybeans supplementation decreased shortchain fatty acids and palmitic acid in milk. In addition, this oilseed enhanced the concentration of conjugated linoleic acid (C18:2 cis-9 trans-11) and vaccenic acid, which improved the milk quality for the human health.

2009 ◽  
Vol 89 (3) ◽  
pp. 315-329 ◽  
Author(s):  
N. Aldai ◽  
M E.R. Dugan ◽  
D C Rolland ◽  
J K.G. Kramer

A survey of Canadian retail beef was undertaken with emphasis on the trans fatty acid (TFA) and conjugated linoleic acid (CLA) isomers, and compared with current health recommendations. Thirty striploin steaks were collected in the winter and summer from major grocery stores in Calgary (Alberta, Canada). Steak fatty acid compositions (backfat and longissimus lumborum muscle analysed separately) showed minor seasonal differences with lower total saturates (P < 0.05) and higher total monounsaturates (P < 0.01) in winter, but no differences in total polyunsaturated fatty acids. The ratio of n-6 and n-3 polyunsaturated fatty acid in longissimus lumborum averaged 5.8. The average TFA content in longissimus lumborum was 0.128 g 100 g-1 serving size, and 10t-18:1 was found to be the predominant isomer (32% of total trans), while vaccenic acid was second most abundant (15% of total trans). The CLA content in longissimus lumborum was similar to that of backfat, ranging from 0.43 to 0.60% and rumenic acid represented 60% of total isomers. Overall, there is still room for improvement in the saturated, mono- and polyunsaturated fatty acid composition of Canadian beef to meet general dietary guidelines for human consumption and additional targets should include reducing 10t-18:1 while increasing both rumenic and vaccenic acids.Key words: Survey, beef, conjugated linoleic acid, survey, trans fatty acids, vaccenic acid


2000 ◽  
Vol 83 (11) ◽  
pp. 2620-2628 ◽  
Author(s):  
D.C. Donovan ◽  
D.J. Schingoethe ◽  
R.J. Baer ◽  
J. Ryali ◽  
A.R. Hippen ◽  
...  

2008 ◽  
Vol 75 (3) ◽  
pp. 354-356 ◽  
Author(s):  
Michael R F Lee ◽  
John K S Tweed

This study investigated the evolution of trans-9 trans-11 conjugated linoleic acid (CLA) from cis-9 trans-11 CLA during methylation and its avoidance through a rapid base methylation of milk fat. The study examined three conditions shown to result in loss of cis-9 trans-11 CLA during methylation namely: temperature, methylation time, water contamination in old reagents and acidic conditions. Three techniques currently used for the conversion of milk fat into fatty acid methyl esters for analysis of CLA content by gas liquid chromatography and a fourth procedure designed to eliminate acidic conditions and to limit methylation temperature and time were used. The four methods were: (i) acidic methylation (AM); (ii) acidic and basic bimethylation with fresh reagents (FBM); (iii) acidic and basic bimethylation with pre-prepared reagents (PBM) and (iv) basic methylation (BM). Each regime was carried out on six milk samples over two periods and methylated 1 ml freeze-dried milk (n=12 per regime). Total CLA was not different across methylation regimes (0·30 mg/ml). Isomer cis-9 trans-11 was higher (P<0·01) with BM than the other regimes and lowest with AM: 21·2, 17·8, 18·8 and 14·7 mg/100 ml for BM, FBM, PBM and AM, respectively. The inverse relationship was shown for trans-9 trans-11 with higher (P<0·001) amounts with AM than the other regimes and lowest with BM: 0·57, 2·55, 2·36 and 3·69 mg/100 ml for BM, FBM, PBM and AM, respectively. The trans-10 cis-12 isomer was also shown to alter with methylation procedure being higher (P<0·001) with AM than the other regimes: 0·43, 0·47, 0·29 and 1·20 mg/100 ml for BM, FBM, PBM and AM, respectively. Validation with known CLA free fatty acid and triacylglycerol standards confirmed that AM resulted in conversion of cis-9 trans-11 to trans-9 trans-11, and also elevated trans-10 cis-12 whilst BM of triacylglycerol CLA did not isomerise cis-9 trans-11 and was comparable to FBM.


2002 ◽  
Vol 74 (1) ◽  
pp. 163-176 ◽  
Author(s):  
A.L. Lock ◽  
P.C. Garnsworthy

AbstractIt may be desirable to increase the level of conjugated linoleic acid (CLA) in milk as a health benefit in human nutrition. The purpose of this work was to separate the effects of linoleic and linolenic acids on CLA production in dairy cows and to determine to what extent endogenous synthesis contributes to cis-9, trans-11 CLA concentration in milk fat. Eight lactating cows and four non-lactating duodenal fistulated cows were used in a 4 ✕ 4 Latin-square design. All cows received a basal diet of grass silage that was supplemented with one of four concentrates, which were designed to differ in their linoleic and linolenic acid contents. The oil components of the concentrates were produced from mixtures of olive, linseed, rape, soya and sunflower oils to produce the four treatments: low linoleic/ low linolenic acid (LL), low linoleic/high linolenic acid (LH), high linoleic/low linolenic acid (HL) and high linoleic/ high linolenic acid (HH). Milk cis-9, trans-11 CLA contents were 0·8, 0·9, 0·9 and 1·1 g/100 g fatty acid methyl esters (P < 0·05) and yields were 5, 7, 7 and 8 g/day (P < 0·05) for the LL, LH, HL and HH treatments, respectively. The yields of trans-C18:1 fatty acids in milk were 19, 22, 21 and 23 g/day (P < 0·05), respectively. Taking the data for the cis-9, trans-11 CLA content and flow of duodenal fluid from the fistulated cows and representing this in terms of dietary intake by the lactating animals, the amounts of cis-9, trans-11 CLA produced in the rumen were calculated to be 0·8, 0·9, 1·2 and 1·1 g/day (P < 0·05) and for trans-C18:1 fatty acids 58, 58, 66 and 69 g/day (P < 0·05). Increasing linoleic and/or linolenic acids in the diet can increase the cis-9, trans-11 CLA content of cows’ milk. Only diets high in linoleic acid increased cis-9, trans-11 CLA production in the rumen. On all four diets, more than 80% of cis-9, trans-11 CLA in milk was produced endogenously by Δ9-desaturase from trans-11 C18:1 in the mammary gland. Cows on the same diet have different milk fat cis-9, trans-11 CLA concentrations that may be partially explained by differences in Δ9-desaturase activity between cows. Increasing the activity of Δ9-desaturase in the mammary gland may offer greater potential for enhancing the cis-9, trans-11 CLA content of milk fat than increasing cis-9, trans-11 CLA production in the rumen.


2000 ◽  
Vol 25 ◽  
pp. 283-293
Author(s):  
F. Lawless ◽  
J.J. Murphy ◽  
S. Fitzgerald ◽  
B. O’Brien ◽  
R. Devery ◽  
...  

AbstractConjugated linoleic acid (cis-9, trans-11-C18:2; CLA) in milk arises as a result of microbial biohydrogenation of dietary linoleic and linolenic acids in the rumen (Kepler and Tove, 1967). Milk fat CLA concentrations were significantly (P<0.05) higher when cows were fed silage supplemented with pulp’n brew (a mixture of brewers grains, a by-product of the brewing industry, and sugar beet pulp in dry matter proportions of 0.65:0.35), compared with silage alone (Trial 1). Intake of spring grass resulted in a 2.1–fold increase in milk fat CLA concentrations over cows receiving autumn grass. Throughout lactation in Trial 2, spring calving cows produced higher milk fat CLA concentrations (from 0.5-2.7 g/100 g fatty acid methyl esters (FAME)) than autumn calving cows (0.3-1.7 g/100 g FAME); the former having spent 80% and the latter 50% of lactation on pasture. The CLA content was higher in late lactation milk compared with early lactation milk in both herds. There were no significant differences in milk yields or milk constituent yields between the herds. Manufacturing milk obtained between March and September was analyzed for milk fatty acid composition and the data correlated with grass growth throughout the season. Significant positive correlations were obtained between grass growth rates and concentrations of CLA and linolenic acid in milk fat. The data indicate that seasonal variation in milk fat CLA concentrations may be attributed to variation in pasture growth rates.


2011 ◽  
Vol 51 (2) ◽  
pp. 95 ◽  
Author(s):  
O. Dayani ◽  
G. R. Ghorbani ◽  
A. K. Esmailizadeh

Eight multiparous Holstein cows in mid lactation (average days in milking of 160 ± 40) were used in a replicated 4 by 4 Latin square design, each experimental period lasting 3 weeks, to determine the effects of whole cottonseed (WCS) treatment and dietary crude protein (CP) concentration on the profile of milk fatty acids. Each 3-week experimental period consisted of 2 weeks for ration adaptation followed by 1 week for data collection. The experimental diets consisted of: (1) Control (without WCS), 16% CP; (2) 20% WCS, 16% CP; (3) 20% WCS, 13% CP; and (4) 20% crushed WCS, 13% CP. Minerals and vitamin supplements were the same in all experimental diets. The WCS treatment led to increased DM intake, fat-corrected milk yield, fat concentration, proportion of long-chain fatty acids, unsaturated fatty acids and ratio of unsaturated to saturated fatty acids (P < 0.05). Decreased concentration of dietary CP from 16 to 13% (diet 2 compared with diet 3) led to a decrease in both milk yield and milk composition (P < 0.05). WCS crushed in diets with 13% CP (diet 4 compared with diet 3) increased (P < 0.05) the concentration of conjugated linoleic acid in milk fat. The results demonstrated that adding WCS to the diet of lactating cows improves both milk yield and milk fatty acid profile, particularly the proportion of conjugated linoleic acid.


Sign in / Sign up

Export Citation Format

Share Document