Total Conjugated Linoleic Acid Content Research Articles

Impact of safflower oil derived conjugated linoleic acid supplementation on fatty acids profile, lipolysis and sensory properties of cheddar cheese

ABSTRACT Nutritionists recommend to consume 3 g Conjugated linoleic acid (CLA) to prevent cancers, cardiovascular diseases, diabetes, obesity and other lifestyle-related disorders. To fulfill the daily requirements of CLA, large proportions of dairy and meat products have to be included in the dietary plan that may have negative impacts such as excessive intake of fat, cholesterol, and lactose. Current investigation was aimed to determine the effect of safflower oil derived CLA on fatty acids composition, lipolysis and sensory properties of cheddar cheese. Safflower oil-derived conjugated linoleic acid (CLA) was added to cheddar cheese at four levels i.e. 1%, 2%, 3% and 4% concentrations (T1, T2, T3 & T4), cheese without CLA supplement was used as control, vacuum packaged samples were ripened at 6–8°C for 90 days. Analysis of CLA supplement revealed that concentrations of ∆9c,11 t-18:2, ∆10 t,12c-18:2, ∆9c,11c-18:2, ∆9 t, 11c-18:2 were 52.16, 44.37, 0.27 and 0.55 mg/100 g. In control, concentrations of ∆9c,11 t-18:2 and ∆10 t,12c-18:2 was 0.24% and 0.07% with a total CLA content of 0.31%. In T3, concentrations of ∆9c,11 t-18:2, ∆10 t,12c-18:2, ∆9c,11c-18:2 and ∆9 t, 11c-18:2 were 1.12, 3.82, 1.63, 2.77 (total CLA 8.34mg100g). In T4, concentrations of ∆9c,11 t-18:2, ∆10 t,12c-18:2, ∆9c,11c-18:2 and ∆9 t, 11c-18:2, were 1.47, 3.50, 3.25 and 3.44% (total CLA 11.67 mg/100 g). Supplementation of cheddar cheese at all four levels significantly increased the concentrations of lactic acid, citric acid, propionic and acetic acids. After 90 days of ripening, free fatty acids in control, T1, T2, T3 and T4 were 0.14, 0.19, 0.23, 0.29 and 0.37% with no difference in composition and sensory properties. These results suggested that CLA content of cheddar cheese can be successfully increased with safflower oil-derived CLA supplement.

Physicochemical property optimization and nutrient redistribution in the muscle of sub-adult grass carp (Ctenopharyngodon idella) by conjugated linoleic acid.

We studied the effects of conjugated linoleic acid (CLA) on the amount of nutrients, flavour substances, and healthcare fatty acids, the physicochemical properties, and the potential molecular mechanisms in the muscles of sub-adult grass carp (Ctenopharyngodon idella). Fish were fed graded levels of CLA (0.0, 3.1, 6.4, 9.6, 12.7, and 15.9g/kg diets) for 60days. Protein, glutamic acid, alanine, inosine monophosphate (IMP), eicosapentaenoic acid (EPA; 20:5n-3), docosahexaenoic acid (DHA; 22:6n-3), and total CLA contents (p<0.05) increased in CLA 3.1∼12.7, 6.4∼9.6, 6.4∼9.6, 6.4∼15.9, 3.1∼9.6, 3.1∼9.6, and 3.1∼15.9g/kg diet, respectively (p<0.05). In addition, optimal CLA significantly increased pH24, shear force, collagen content, and myofibre density in the muscle (P<0.05); however, it decreased myofibre diameter (p<0.05). We concluded that 6-9g/kg CLA in the diet could improve the flesh quality of sub-adult grass carp.

Catalyst activation by cold plasma technology and its effect on isomerization of safflower seed oil

High voltage atmospheric cold plasma (HVACP) is a novel catalyst modification technology. In this study, a ruthenium/multi-walled carbon nanotubes (Ru/MWCNTs) catalyst was activated by HVACP instead of the thermal reduction method. The results showed that HVACP activation under the conditions of 180 s discharge time, 150 W discharge power, and 2.5 cm electrode spacing at 25 °C could effectively decrease the activation temperature and time. At this time, the Ru dispersion was 20.1% and the conjugated linoleic acid (CLA) yield was 43.0%. Catalyst characterization proved that the HVACP-treated catalyst did not aggregate and had a good activation effect. The catalyst was applied to the isomerization reaction of safflower seed oil to obtain CLA-rich safflower seed oil. The total CLA content was 43.02%, the trans-oleic acid content was 1.34%, the iodine value (IV) was 133.50 gI2/100 g, and after reusing five times, the relative activity of the catalyst remained at 77%, which provided the conditions for the preparation of functional oil.

Milk Fat Depression and Trans-11 to Trans-10 C18:1 Shift in Milk of Two Cattle Farming Systems

Milk fat depression (MFD) syndrome, a consistent decrease in milk fat content, is related to important changes in fatty acid composition due to feed imbalances and the consequent ruminal metabolism alteration. Milk produced in two different farming systems was compared: Holstein Friesian fed with unified in intensive production and Podolica raised on a pasture in an extensive system. Milk chemical characteristics and fatty acid composition were determined comparing milk with a normal fat level (&gt;3.8%) to milk with a low fat level (&lt;3.2%) in each breeding system. Holstein Friesian milk showed the decrease in trans-11 and increase in trans-10 C18:1 (shift from trans-11 to trans-10 C18:1) in low fat with respect to normal fat milk with a consequent decrease in the trans-11/trans-10 C18:1 ratio. Even conjugated linoleic acid (CLA), C18:2 cis-9, trans-11, was lower while CLA trans-10, cis-12 was higher in low fat milk than in normal fat milk from Holstein Friesian. These changes, that are indicators of MFD syndrome, were not found in Podolica milk between fat levels. Holstein Friesian milk showed less short-chain fatty acids (9.48 % vs. 11.05%, p &lt; 0.001), trans vaccenic acid (C18:1 trans-11, 0.51% vs. 3.39%, p &lt; 0.001), rumenic acid (CLA C18:2 cis-9, trans-11, 0.32% vs. 1.45%, p &lt; 0.001) and total CLA (0.53% vs. 1.91%, p &lt; 0.001) contents than Podolica milk. Further losses of these human healthy nutrients in low fat Friesian milk reduced the nutritional quality of the milk, while the milk from animals raised on the pasture was of better quality even when the level of fat was low.

Efficient conversion of conjugated linoleic acid c9,t11 by Lactobacillus fermentation from vegetable oil to generate fermented milk with high CLA content

The purpose of this study was to develop a functional and valuable dairy product with high conjugated linoleic acid (CLA) content through a fermentation method utilizing vegetable oil and probiotic lactic acid bacteria. Bifidobacterium breve KCTC 3419 was selected as a standard strain for high efficiency conversion of the CLA c9,t11. This standard strain was mixed in a definite ratio of 4:3:3 with Lactobacillus sakei LJ011 isolated from kimchi and the commercially available YF-L812 culture to generate a high-efficiency CLA conversion starter stock for use in fermented milk production. CLA conversion by safflower seed oil fermentation by the starter stock yielded the highest CLA containing fermented milk. The pH level, titratable acidity, and number of lactic acid bacteria in the fermented milk were altered to suitable levels during the fermented milk production process. The CLA content of CLA-fermented milk was maintained at 0.1% of the total CLA content during the storage period of 2 weeks.

Fatty acid profile of goat milk in diets supplemented with chia seed (Salvia hispanica L.).

Chia seed (Salvia hispanica L.) is the greatest known plant source of n-3 α-linolenic acid. The present study evaluated the effects of 3 inclusion levels of chia seed [zero (control); low, 2.7% (CLow); and high, 5.5% (CHigh)] in diets of dairy goats on milk yield and fatty acid profile. Nine Saanen dairy goats in the last third of lactation period, live weight 38 ± 8.7 kg, housed in metabolic cages, were fed iso-proteic and iso-energetic (160 g of crude protein/d and 11 MJ of metabolizable energy/d) diets. Gas chromatography was used to analyze fatty acid profile and total conjugated linoleic acid (CLA). Silver ion HPLC was used to analyze the isomeric profile of CLA. The results were subjected to variance analysis using a Latin square design repeated 3 × 3. The CHigh treatment was higher for dry matter, neutral detergent fiber, and acid detergent fiber intake compared with CLow and control diets. Digestibility was not affected by the inclusion of chia seeds. The CHigh diet improved N intake with respect to the control and CLow diet. Milk yield and chemical composition were not affected by the treatment. The milk fatty acid profile of C18:0, C18:1, C18:2, and C:20 was higher for CHigh than the other treatments. The in vitro gas production (mL of gas/g of dry matter) was lower in CHigh than the control diet. In conclusion, the addition of chia seeds at the CHigh level in dairy goat diets negatively affected in vitro rumen fermentation, but increased the milk fatty acid profile of C18:0, C18:1n-9 cis, and C:20, monounsaturated fatty acids, and polyunsaturated fatty acids. The total CLA content increased from 0.33 to 0.73% with the supplementation of chia to the diet, as well as the isomers cis-9,trans-11, trans-7,cis-9, trans-11,cis-13, and trans-12,trans-14.

Dietary supplementation of Butyrivibrio fibrisolvens alters fatty acids of milk and rumen fluid in lactating goats.

Conjugated linoleic acid (CLA) isomers have high health amelioration potential and hence it is of great interest to increase the CLA content in dairy products. The present study was conducted to investigate the effect of administration of high CLA producing Butyrivibrio fibrisolvens In-1 on fatty acid composition of milk and rumen fluid in lactating goats. Four groups (n = 5) of lactating goats were assigned the following treatments: Control (C) (basal diet); T1 (basal diet + linoleic acid source), T2 (basal diet + suspension of Butyrivibrio fibrisolvens In-1, 10(9) CFU head(-1)) and T3 (basal diet + linoleic acid source + suspension of Butyrivibrio fibrisolvens In-1, 10(9) CFU head(-1)). Rumen liquor and milk samples were collected on days 0, 15, 30, 60 and 90 of the experiment and linoleic isomerase enzyme (LA-I) activity and fatty acid profiles were elucidated. Major effects of treatments were seen on day 30 of the experiment. Total CLA content of rumen fluid increased (P < 0.05) by 218.72, 182.26 and 304% whereas total saturated fatty acid (SFA) content was lowered (P < 0.05) by 6.1, 4.44 and 9.55% in T1, T2 and T3, respectively, as compared to control. Vaccenic acid in groups T2 and T3 increased (P < 0.05) by 66.67% and 105.7% as compared to control. In milk, total CLA increased by 2.03, 1.61 and 0.61 folds in T3, T2 and T1, respectively. Total monounsaturated fatty acid and polyunsaturated fatty acid content increased (P < 0.05) in group T3 by 14.15 and 37.44%, respectively. Results of the present study indicated that administration of B. fibrisolvens In-1 along with a linoleic acid (LA) source is a useful strategy to alter the biohydrogenation pattern in the rumen that subsequently decreased SFA content while increased CLA and unsaturated fatty acids in ruminant's milk.

Rapid determination of total conjugated linoleic acid concentrations in beef by 1H NMR spectroscopy

Nuclear magnetic resonance (NMR) spectroscopy was employed to determine the conjugated linoleic acid (CLA) content in beef muscle tissue. NMR is an inviting and greener alternative to traditional methods such as gas chromatography (GC), which can require time-consuming sample derivatization and use of large quantities of solvents. In this work, a new rapid and reliable lipid extraction protocol was combined with simple, non-destructive 1H NMR spectroscopic analysis to measure the total CLA content in 41 Canadian beef ribeye steaks purchased in western Canada. The total CLA concentrations (mg/100g meat) obtained using the new extraction and analysis methods were consistent with amounts found using the traditional lipid extraction and GC analysis (correlation coefficient of 0.961).

Stability of fatty acid composition after thermal, high pressure, and microwave processing of cow milk as affected by polyunsaturated fatty acid concentration

Interest has been increasing to enhance the contents of healthy polyunsaturated fatty acid (PUFA) in milk. However, trans fatty acids and conjugated linoleic acid (CLA) can be altered after thermal processing and high pressures disrupt the milk fat globule membrane, exposing the lipid core and helping its oxidation. The objective of the present research was to study whether processing can alter the fatty acid composition of milk and if these changes are affected by PUFA concentration as previous studies suggest. Two cow milk batches (500L each), one naturally enriched in PUFA, were processed to obtain pasteurized; high temperature, short time; UHT; high pressure; and microwave pasteurized samples. The detailed fatty acid composition was analyzed with special attention to trans fatty acids and CLA isomers. Results showed that after high temperature, short time processing, total CLA content increased in both milk batches, whereas sterilization resulted in a sigmatropic rearrangement of C18:2 cis-9,trans-11 to C18:2 trans-9,trans-11. The extent of these effects was greater in milks naturally enriched in PUFA.

Rapid Determination of Total Conjugated Linoleic Acid Content in Select Canadian Cheeses by1H NMR Spectroscopy

The application of (1)H nuclear magnetic resonance (NMR) spectroscopy to the measurement of conjugated linoleic acid (CLA) content in the lipid fraction of dairy products is both a novel and inviting alternative to traditional methods such as gas chromatography (GC), which can require time-consuming sample derivatization. In this work, a newly developed, rapid, and reliable lipid extraction protocol was combined with simple, nondestructive (1)H NMR spectroscopic analysis to measure the total CLA content in CLA standards and in various Canadian cheeses from conventional, organic, and grass-fed dairy sources. The total CLA concentrations (mg/g cheese) obtained using these new extraction and analysis methods were consistent with amounts found using the modified Folch extraction and GC analysis (correlation coefficient of 0.948). Results showed that cheeses from exclusively grass-fed dairy cows were significantly higher in total CLA content than either conventional or organic cheese.

Starter cultures and cattle feed manipulation enhance conjugated linoleic acid concentrations in Cheddar cheese

Conjugated linoleic acid (CLA) is a fatty acid (FA) that provides several health benefits to humans. The feeding of fish oil-supplemented diets to dairy cows has been extensively studied as a means to improve the CLA content in milk. Several studies have also been conducted on the ability of many microorganisms to produce CLA by utilizing substrates containing linoleic acid. In the present study, the dietary manipulated milk was used in combination with the CLA-producing culture to manufacture Cheddar cheese. The two diets fed to cattle were control and treatment diets to obtain control and treatment milk, respectively. The treatment diet containing fish oil (0.75% of dry matter) was fed to 32 dairy cows grouped in a pen for 18 d to increase the total CLA content in milk. Treatment milk had a CLA content of 1.60g/100g of FA compared with 0.58g/100g of FA in control milk obtained by feeding the control diet. A 2 × 2 factorial design with 3 replicates was used to test the combined effect of the CLA-producing starter culture of Lactococcus lactis (CI4b) versus a commercial CLA nonproducing cheese starter as the control culture, and type of milk (control vs. treatment milk) on CLA content in Cheddar cheese. Chemical composition (moisture, salt, fat, and protein) was not affected by the type of culture used. However, the age of the cheese affected the sensory properties and microbiological counts in the different treatments. Ripening with the CI4b culture was found to be effective in further enhancing the CLA content. The CI4b cheeses made from control milk and treatment milk contained 1.09 and 2.41 (±0.18) g of total CLA/100g of FA after 1 mo of ripening, which increased to 1.44 and 2.61 (±0.18) g of total CLA/100g of FA after 6 mo of ripening, respectively. The use of treatment milk resulted in an increase in the CLA isomers (trans-7,cis-9+cis-9,trans-11, trans-9,cis-11+cis-10,trans-12, trans-10,cis-12, cis-9,cis-11, trans-11,cis-13, cis-11,cis-13, trans-11,trans-13, and trans-9,trans-11). The CI4b culture specifically increased cis-11,cis-13 and trans-10,cis-12 isomers in cheese. The total CLA content in cheese was significantly higher when the CI4b culture was used compared with CLA nonproducing culture cheeses made from control milk and treatment milk after 1 mo [1.09 and 2.14 (±0.18) g of total CLA/100g of FA] and 6 mo [0.99 and 2.05 (±0.18) g of total CLA/100g of FA] of ripening, respectively. The results indicated that the combination of a CLA-producing starter culture and milk from cattle fed fish oil-supplemented diets (0.99g of CLA/100g of FA) could enhance levels of total CLA in Cheddar cheese by up to 2.6 times compared with cheese made from control milk with CLA nonproducing starter culture (2.61g of CLA/100g of FA) after 6 mo.

Conjugated linoleic acid content in milk of Chilean Black Friesian cows under pasture conditions and supplemented with canola seed (Brassica napus) concentrate

At present, there is limited and contradictory information about the effects of the use of canola (Brassica napus) seed as supplement on the contents of conjugated linoleic acid (CLA) in milk of grazing cows. The objective of this study was to evaluate the effect of a dietary supplement with canola seed on the production and composition of milk, and CLA concentration in Chilean Black Friesian cows under pasture conditions. Three experiments were done. Experiment 1: control group was fed 5 kg d-1 of commercial concentrate without canola (0-TC1) and treatment group that was fed 3.75 kg of commercial concentrate plus 1.16 kg of whole canola seed (1.16-TC1). Experiment 2: Control group was fed 8 kg d-1 commercial concentrate without canola (0-TC2) and treatment group that was fed 6.2 kg of commercial concentrate plus 1.2 kg of ground canola seed (1.2-TC2). Experiment 3: control group was fed 6 kg d-1 commercial concentrate without canola (0-TC3) and treatment group was fed 6 kg of commercial concentrate with 20% of whole canola seed (1.2 kg d-1, 1.2-TC3). The duration of each experiment was 60 days. No differences in milk production and quality were observed among the experimental groups in every assay. The CLA isomers trans-10, cis-12 and cis-10, cis-12 were higher than those normally found in the scientific literature. There was no effect of the inclusion of canola seed on total CLA content or the content of cis-9, trans-11, trans-10, cis-12 and cis-10, cis-12 isomers.

Influence of season and pasture feeding on the content of CLA isomers in milk from three different farming systems in Sicily

It has been shown that several factors such as pasture feeding, farming system and season might influence the content of conjugated linoleic acid (CLA) isomers in milk. Four Sicilian traditional dairy farms were selected, two had both Holstein and Brown Swiss cows, which were both at low pasture intake regimen and the other two farms had exclusively Modicana local-breed cows fed at higher pasture intake regimen. Pasture was available during spring and autumn but not during summer. Additional hay and concentrate was supplemented during all periods. The objective of this study was to assess the season effect (spring, summer and autumn) and farming system effect on CLA isomers and total CLA contents in cows’ milk. Autumn compared to summer milk had higher levels of total CLA (3,991.4 vs. 2,804.9 μg.g−1 of fat, respectively). Higher CLA levels in autumn compared to spring milk (3,991.4 vs. 2,662.7 μg.g−1 of fat, respectively) may be explained by different plant phenological stage. Spring compared to summer milk had surprisingly similar levels of total CLA (2,662.7 vs. 2,805.0 μg.g−1 of fat, respectively) this might be explained by higher diet content of concentrate in summer compared to the two grazing seasons (44.5 vs. 36.3% of DM). Milk total CLA levels did not differ significantly among farming systems. A significant variation of cis,trans (c,t) 11–13 and c,t 9–11 levels was only detected in milk from farms with higher pasture intake.

Effect of extruded whole soybean dietary concentrate on conjugated linoleic acid concentration in milk in Jersey cows under pasture conditions

Contradictory results has been found on the effects of soybean supplementation and conjugated linoleic acid (CLA) content in milk on feeding systems based on fresh forage The objective of the study was to evaluate the effect of a dietary supplement with different quantities of extruded whole soybean on the production and composition of milk, and CLA concentration or their isomers in Jersey cows under pasture conditions. Twenty-one Jersey cows were randomly assigned into 3 groups of 7 animals each. The cows were supplemented with a dietary concentrate (5 kg d-1), and each group received one of the three next treatments: control without soybean (0-SB), with extruded whole soybean at 0.5 kg d-1 (0.5-SB) or at 1 kg d-1 (1-SB). The basic diet was a pasture composed of Lolium perenne (70%), Trifolium repens (25%) and other species. The duration of the study was 75 d. Milk production (p = 0.706) and protein production (p = 0.926) were not affected by treatments. Fat (p = 0.015) and protein (p = 0.045) content as well as fat production (p = 0.010) were lower in the 1-SB group. There was no effect of the inclusion of extruded soybean on total CLA content (p = 0.290) or the content of cis-9, trans-11 (p = 0.582), trans-10, cis-12 (p = 0.136) and cis-10, cis-12 (p = 0.288) isomers. However, concentrations of all isomers were affected by the nutritional quality of the pasture, with low values observed at greater maturity stages of pasture.

Effects of different levels of roasted soybeans in high forage-based rations on conjugated linoleic acid of longissimus dorsi muscle, subcutaneous fat and liver of beef cattle

Twelve 24-month-old crossbred beef cattle with initial live weight of 532.6±20.9 kg were used to study the effect of feeding different levels of roasted soybeans on conjugated linoleic acid (CLA) and other fatty acids of longissimus dorsi muscle, subcutaneous fat and liver. The cattle were randomly divided into three groups with 4 cattle in each group and were fed rations containing 3.6, 10.1 and 15.7% of roasted soybeans as Treatments I, II and III, respectively. The cattle were slaughtered after feeding for 28 days and the samples of longissimus dorsi muscle, subcutaneous fat and liver were obtained. The fatty acid composition of the samples was analysed and statistically compared. In longissimus dorsi muscle, it was found that c9t11-CLA content was significantly increased with soybean level (P 0.05). In subcutaneous fat, both c9t11-CLA (P=0.056) and total CLA (P = 0.067) tended to increase with soybean level while all other fatty acids were unchanged (P > 0.05). In liver, content of C18:1 was significantly decreased while contents of C18:2n-6 and C18:3 were significantly increased with soybean level (P < 0.01). Significant correlations were found between intake and contents of fatty acids C18:0, C18:1, C18:2n-6 and C18:3 in liver. This study concludes that feeding beef cattle with soybeans up to 15.7% in high forage-based ration is not an effective way to increase total CLA content of tissues. Key words: Soybeans, conjugated linoleic acid, longissimus dorsi muscle, subcutaneous fat, liver, beef cattle.

Fatty acid and CLA composition of Brazilian dairy products, and contribution to daily intake of CLA

In the present study, the conjugated linoleic acid (CLA) contents of dairy products most consumed by the population living in the southeast region of Brazil (whole milk, “Prato” cheese and butter) were determined. In addition, the contribution of these dairy foods to the daily intake of CLA isomers was estimated. Fatty acid composition was determined by gas chromatography. Quantitative analysis of CLA isomers was done by silver-ion high-performance liquid chromatography (HPLC) and their identification was achieved by gas chromatography–mass spectrometry (GC–MS) of dimethyloxazoline (DMOX) derivatives. Eleven CLA isomers were identified and the predominant were cis-9, trans-11 and trans-7, cis-9. The total CLA contents in whole milk, “Prato” cheese and butter ranged from 4.0 to 8.4 mg/g fat and were similar to those reported for dairy products from other countries. Whole milk samples had significantly higher contents of total CLA, when compared to “Prato” cheese and butter, and the total CLA contents were significantly different between the commercial brands of each dairy product. The estimated average daily intake of total CLA in southeastern Brazil was 36 mg/day, which was lower than those of European and North American countries, and milk was the main food source of CLA in the diet.

Determination by Fourier Transform Raman Spectroscopy of Conjugated Linoleic Acid in I2-Photoisomerized Soybean Oil

The potential of Fourier transform (FT)-Raman spectroscopy to quantify the total conjugated linoleic acid (CLA) content was evaluated to find a technique for the routine control of CLA synthesis by chemical procedures. The calibration and validation samples were obtained by photoisomerization of linoleic acid contained in soybean oil. The catalyst was iodine (I(2)), and the light source was the green line (514.5 nm) of an argon ion laser. The criteria to select the best partial least-squares (PLS) calibration model were a low standard error of prediction (SEP), a high correlation coefficient (R), and the selection of relevant variables of the Raman spectrum to reduce spectral interferences. The total CLA content of the 22 samples ranged from 0.05 to 3.28% of total lipids. The best PLS calibration model was obtained with three optimal factors, a SEP of 0.22, and a R of 0.97. This calibration model was obtained after baseline correction of the CC stretching region (1642-1680 cm(-1)), which contained sufficient spectral information for reliable CLA quantification.

Conjugated linoleic acid content of milk from buffaloes fed a mustard oil‐based diet

Fifteen Murrah buffaloes were distributed in groups I, II and III. The group I animals were fed with groundnut cake‐based concentrate, group II animals with mustard cake‐based concentrate and group III with 2% of mustard oil added to the group II feed. Conjugated linoleic acid (CLA) estimation in milk was done by using GC. The average total CLA contents (mg/g milk fat) in the three groups were 6.84, 12.12 and 19.50 mg/g of fat respectively. Hence it was concluded that addition of 2% mustard oil resulted in a 185% increase in milk fat total CLA content.

Enhancement of the conjugated linoleic acid and vitamin A and E contents in goat milk through green fodder feeding

Twelve lactating crossbred goats (Sanan × Beetal) in early lactation were divided into two groups of six each. Group I was fed on fresh berseem fodder (Trifolium alexandrinum), whereas group II was fed on berseem fodder and concentrate mixture in 1 : 1 ratio to fulfil their nutritional requirements as per National Research Council (1981). Feed intake and milk yield were recorded daily, and milk samples were collected on 0, 30, 45 and 60 days of experimental feeding for the estimation of fat, vaccenic acid, conjugated linoleic acid (CLA), vitamins A and E, and total antioxidant activity. There was no effect (P &gt; 0.05) of dietary treatments on daily as well as total milk yield and milk fat, solids‐not‐fat and total solids, although average total CLA (mg/g fat) content in milk during the trial was higher(P &lt; 0.01) in group I (18.92) in comparison to group II (10.94). Vitamin A content averaged 0.46 and 0.27 µg/mL and vitamin E, 1.20 and 1.38 µg/mL in milk of groups I and II, respectively, were higher in the berseem‐fed group (P &lt; 0.01) and total antioxidant activity of milk was also higher (P &lt; 0.01) in group I than in group II.

Conjugated Linoleic Acid (CLA) content of meat from three muscles of Massese suckling lambs slaughtered at different weights

Eighteen Massese male lambs, fed mainly maternal milk were slaughtered at 11, 14 and 17 kg. Samples of Longissimus Dorsi (LD), Triceps Brachii (TB) and Semimembranosus (Sm) muscles were collected. Milk from the lamb’s dams was sampled weekly. Fatty acid composition of milk and meat was determined. TB was the fattest muscle, Sm the leanest one and LD showed an intermediate value of total lipids, while the weight at slaughter did not influence total intramuscular fat content in any muscle. Although slaughter weight slightly affected overall fatty acid composition of muscles, rumenic acid and total CLA content in TB and Sm, but not in LD, significantly increased with slaughter weight. As regard milk fatty acid composition, the contents of total CLA, RA and others minor CLA isomers decreased during the first four weeks after lambing and then increased at the last control (five weeks). The animals slaughtered at a live weight of 14 and 17 kg showed a greater SCD enzyme activity (estimated by product/substrate ratio) and a higher rumen activity (estimated by means of branched chain and odd chain fatty acid content in meat) than animals slaughtered at 11 kg. Cis-7, trans-9 CLA content significantly increased with the slaughter age in TB and SM, while trans-7, trans-9 CLA, only increased in TB, and cis-8, cis-10 CLA, only increased in SM. Further studies are needed in order to verify weather the different behaviour of RA in LD muscle may be due to differences in muscle metabolism or fatty acid utilisation.