scholarly journals The effect of restricted grazing on the fatty acid composition of ovine rnilk fat during early lactation

1980 ◽  
Vol 44 (1) ◽  
pp. 47-52 ◽  
Author(s):  
E. Payne ◽  
P. V. Rattray

1. The fatty acid composition of milk fat of Coopworth sheep offered varying pasture allowances has been determined after 1, 14 and 35 d of lactation. Differences in fatty acids occurred, particularly between 1 and 14 d, with a major increase in C18:0 whilst C16:0, C14:0 and C18:3 showed decreases.2. When pasture allowances were restricted there were decreases in the short-chain fatty acids from C6 to C14 and an increase in C18:1 as has been observed previously for cattle. The C18:1:C10 value is a convenient measure of these changes and can be determined more rapidly than determining all the lower fatty acids.3. The increased demand for milk resulting from suckling twin lambs caused an increase in C18:1 and decreases in C10 and C12 due to an increased utilization of body reserves.4. The level of linoleic acid was much greater than has been previously observed in sheep given hay and contributes to the rapid rise in linoleic acid levels in lambs born under grazing conditions.

2003 ◽  
Vol 70 (3) ◽  
pp. 257-265 ◽  
Author(s):  
Chakra Wijesundera ◽  
Zhiping Shen ◽  
William J Wales ◽  
Dawn E Dalley

Two experiments were undertaken to determine the effects of cereal grain and fibre (hay or straw) supplements on the fatty acid composition of milk fat of grazing dairy cows in early lactation. In both experiments, grain supplements significantly increased (P<0·05) the proportion of the endogenously synthesized 10[ratio ]0–16[ratio ]0 fatty acids. Of the C18 acids, the proportion of 18[ratio ]0 and 18[ratio ]3 was significantly decreased (P<0·05) by grain supplementation, while that of 18[ratio ]2 was significantly increased (P<0·05). Irrespective of diet, 18[ratio ]1 trans-11 was the most dominant trans 18[ratio ]1 isomer in milk fat. In the first experiment, the proportions of the 18[ratio ]1 trans-11 isomer and conjugated linoleic acid (CLA, 18[ratio ]2 cis-9, trans-11) were highest for the pasture-only diets, and significantly (P<0·05) decreased with grain supplementation. The opposite result was observed in the second experiment, conducted in a different dairy region, suggesting that factors such as the quality of pasture on offer and the physiological state of the cow could affect the content of CLA and trans fatty acids in milk fat. In both experiments, there was a significant positive linear relationship between CLA and 18[ratio ]1 trans-11. Fibre supplements had little effect on the fatty acid composition of the milk.


2015 ◽  
Vol 31 (1) ◽  
pp. 45-53
Author(s):  
G. Gerchev ◽  
N. Naydenova ◽  
S. Slavkova ◽  
G. Mihaylova

The study was conducted on aggregate milk samples, which were taken every month during the milking period from Tzigay sheep and their F2 cross-breeds of Chios, raised in the conditions of the Central Balkan Mountain. The fat extraction of milk samples was done by the Rose-Gottlieb method. Fatty acid composition was determined on a gas chromatograph with flame ionization detector and capillary column. The aim of the study was to follow the changes in the composition of fatty acids in the milk fat of milk of Tzigay sheep and their F2 cross-breeds. The saturated fatty acids in milk of the two groups had high values during both consecutive years, as they varied from 67.05% in milk of Tzigay sheep in the second lactation up to 70.87% at their F2 cross-breeds. The content of myristic acid was correspondingly 8.22-8.88% at Tzigay sheep and 8.45-8.74% at their F2 cross-breeds. The total amount of polyunsaturated fatty acids in the examined milk for the two types of sheep was comparatively low with near concentrations (4.39-5.20%) in the period of the two years. The milk of the two groups had high values of the correlation SFA/PUSFA (15.71 and 13.17) and low values of PUSFA/SFA (0.06-0.08). Mon?unsaturated fatty acids, represented mainly by the oleic acid (C18:1) varied during both periods from 21.92% to 25.32% and appeared as a substratum in the synthesis of CLA. The short-chain fatty acids (C4:0-C11:0) had higher values in Tzigay sheep in comparison with F2 cross-breeds of Chios. The long-chain fatty acids (C17iso-C25:0) maintained close concentration in the milk of Tzigay breed, while their content in the milk of F2 cross-breeds was increased.


1972 ◽  
Vol 71 (1) ◽  
pp. 62-72 ◽  
Author(s):  
Knut Kirkeby

ABSTRACT The fatty acid composition of cholesterol esters, phospholipids, and triglycerides of the serum has been studied in groups of hyperthyroid and hypothyroid women and also in control material matched for age. In hyperthyroidism, a decrease in the proportions of linoleic acid and an increase in the proportions of some saturated and mono-unsaturated fatty acids were observed. When absolute concentrations were considered, it appeared that the decrease in linoleic acid was almost equivalent to the entire decrease in total fatty acids in the serum of the hyperthyroid patients. In hypothyroidism no changes were noted in the proportions of linoleic, saturated and mono-unsaturated fatty acids, and the absolute concentrations reflected the general increase in serum lipids. It is believed that these findings may be explained by the changes in lipid turnover which are known to occur in disturbances of thyroid function. In hyperthyroidism, they lead to a linoleic acid deficiency, while a sparing effect must be operating in hypothyroidism. The finding of relatively high linoleic acid values combined with hyperlipaemia in hypothyroidism seems to be characteristic of the condition, since other types of hyperlipaemia are almost invariably combined with low percentages of linoleic acid. Results regarding arachidonic and eicosatrienoic acid are consistent with increased synthesis in hyperthyroidism, and decreased synthesis in hypothyroidism.


2009 ◽  
Vol 92 (10) ◽  
pp. 4865-4875 ◽  
Author(s):  
M. Carriquiry ◽  
W.J. Weber ◽  
C.R. Dahlen ◽  
G.C. Lamb ◽  
L.H. Baumgard ◽  
...  

Nutrients ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1972 ◽  
Author(s):  
Wesolowska ◽  
Brys ◽  
Barbarska ◽  
Strom ◽  
Szymanska-Majchrzak ◽  
...  

Human milk fat plays an essential role as the source of energy and cell function regulator; therefore, the preservation of unique human milk donors’ lipid composition is of fundamental importance. To compare the effects of high pressure processing (HPP) and holder pasteurization on lipidome, human milk was processed at 62.5 °C for 30 min and at five variants of HPP from 450 MPa to 600 MPa, respectively. Lipase activity was estimated with QuantiChrom™ assay. Fatty acid composition was determined with the gas chromatographic technique, and free fatty acids content by titration with 0.1 M KOH. The positional distribution of fatty acid in triacylglycerols was performed. The oxidative induction time was obtained from the pressure differential scanning calorimetry. Carotenoids in human milk were measured by liquid chromatography. Bile salt stimulated lipase was completely eliminated by holder pasteurization, decreased at 600 MPa, and remained intact at 200 + 400 MPa; 450 MPa. The fatty acid composition and structure of human milk fat triacylglycerols were unchanged. The lipids of human milk after holder pasteurization had the lowest content of free fatty acids and the shortest induction time compared with samples after HPP. HPP slightly changed the β-carotene and lycopene levels, whereas the lutein level was decreased by 40.0% up to 60.2%, compared with 15.8% after the holder pasteurization.


Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1667 ◽  
Author(s):  
Beata Paszczyk ◽  
Joanna Łuczyńska

This study aimed to evaluate the fatty acid composition, including the contents, of conjugated linoleic acid cis9trans11 C18:2 (CLA) and trans C18:1 and C18:2 isomers in hard cow, sheep, and goat cheeses found on the Polish market and to compare lipid quality indices in these cheeses. The gas chromatography method was used to determine the fatty acid profile. The study demonstrated various contents of cis9trans 11 C18:2 (CLA), trans C18:1, and C18:2 isomers and the values of lipid quality indices in the cheeses. Sheep and goat cheeses were richer sources of short-chain fatty acids (SCFA) (14.73 ± 2.55% and 14.80 ± 2.80%, respectively) than the cow cheeses (9.38 ± 0.87%). The cow cheeses had a significantly higher (p < 0.05) content of monounsaturated fatty acids (MUFA), the lowest n-6/n-3 ratio, and the highest content of fatty acids, inducing a desirable dietary effect in humans (DFA) compared to the sheep and goat cheeses. Significantly higher (p < 0.05) contents of polyunsaturated fatty acids (PUFA) were found in sheep cheeses. Goat cheeses had the highest n-3 PUFA content and the lowest values of the thrombogenicity index (TI) (2.67 ± 0.44) compared to the sheep and cow cheeses (3.14 ± 0.29 and 3.13 ± 0.13, respectively). The cow, sheep, and goat cheeses were characterized by similar values of the hypocholesterolemic/hypercholesterolemic (H/H) ratio. Sheep cheeses had the highest levels of cis9trans11 C18:2 (CLA) and the highest total content of trans C18:1 and trans C18:2 isomers. The research showed that sheep, cow, and goat cheeses offered various health benefits. The differences in fatty acid composition and the different values of the lipid quality indices found in the cheeses may be due to differences in both the composition of milk used to produce them and the cheese-making technology. Studies conducted by many authors have indicated that the feeding system of the ruminants has a significant impact on the quality and chemical composition of milk, as well as its applicability for cheese production.


2005 ◽  
Vol 72 (3) ◽  
pp. 349-361 ◽  
Author(s):  
Kevin J Shingfield ◽  
Pirjo Salo-Väänänen ◽  
Eero Pahkala ◽  
Vesa Toivonen ◽  
Seija Jaakkola ◽  
...  

Based on potential health benefits, there is a need to develop effective strategies for enhancing milk fat concentrations of cis-9 18[ratio ]1, 18[ratio ]3 n-3 and conjugated linoleic (CLA) content in milk without compromising the sensory or storage characteristics of processed milk or dairy products. Sixteen Finnish Ayrshire dairy cows were used in a cyclic change-over experiment with four 21-d experimental periods and a 4×2×2 factorial arrangement of treatments to evaluate the effects of forage conservation method, concentrate level and supplements of propylene glycol (PG), and their interactions on milk fatty acid composition and vitamin content. Experimental treatments consisted of four conserved forages offered ad libitum, supplemented with two levels of a standard concentrate (7 or 10 kg/d) and PG (0 and 210 g/d) fed as three equal meals. Primary growths of timothy and meadow fescue sward were conserved by ensiling with none (NA), an inoculant enzyme preparation (IE) or a formic acid based (FORM) additive or as hay 1 week later. Conservation of grass by drying rather than ensiling resulted in lower forage 18[ratio ]2n-6, 18[ratio ]3n-3, total fatty acid and fat-soluble vitamin concentrations. In spite of lower intakes, milk fat 18[ratio ]2n-6 and 18[ratio ]3n-3 content was higher (P<0·05) for hay than for silage diets (12·1, 9·6, 9·6 and 9·3 and 5·00, 3·51, 4·27 and 2·93 g/kg total fatty acids, for hay, NA, IE and FORM silages, respectively). Forage conservation method had no clear effects on milk trans 18[ratio ]1 or CLA content. Compared with silage, hay diets resulted in milk containing lower (P<0·001) riboflavin, α-tocopherol and β-carotene concentrations, but had no effect on ascorbic acid, thiamine, pyridoxine or retinol content. Feeding more concentrates had no effect on milk fatty acid composition or milk vitamin content, other than lowering (P<0·001) 16[ratio ]0 concentrations from 348 to 338 g/kg fatty acids. Supplements of PG led to small (P<0·05) increases in milk 13[ratio ]0 anteiso and 15[ratio ]0 content from 1·06 and 11·3 to 1·22 and 12·6 g/kg fatty acids and reduced (P<0·05) the concentrations of ascorbic acid (16·1 v. 15·1 g/kg milk).


1970 ◽  
Vol 48 (3) ◽  
pp. 264-268 ◽  
Author(s):  
E. Y. Lipsitz ◽  
J. E. McFarlane ◽  
G. O. Henneberry

The fatty acid composition of larvae of Acheta domesticus (L.) at two distinct ages (12 days and 30 days) was determined. No appreciable age differences were observed in the composition of fatty acids from lipid extracts; palmitic, stearic, oleic, and linoleic acids were found to be the major fatty acids, together accounting for about 90% of the total. However, distinct age differences were found in the fatty acid composition of neutral lipid components. The most marked developmental change was a reduction from 34.5% to 10.9% in the myristic acid content of the monoglyceride. High concentrations of short-chain fatty acids were found in at least three neutral lipid components, and considerable alterations in the concentration of these fatty acids occurred during development.


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