Fatty Acid Composition Of Lamb Research Articles

Effects of oregano essential oil and capsicum extract supplementation on slaughter characteristics, meat quality, and fatty acid composition of lambs

The aim of this study was to evaluate the effect of oregano essential oil (OEO) and capsicum oleoresin extract (CAO) supplementation on lamb slaughter characteristics, meat quality, and fatty acid composition. In the study, 18 male and 18 female lambs were divided into three equal groups for a 56- day feeding period. The first group was fed the control diet, while the other groups were fed a control diet containing either 300 mg OEO/kg or 300 mg CAO/kg of diet. Feeding OEO or CAO had no effect on the slaughter and carcass quality of the fattening lambs. However, when compared to the female lambs, the male lambs were found to have higher slaughter weights, hot and cold carcass weights, and dressing percentage, while having lower back fat thickness. In addition, OEO substantially increased the intramuscular fat. Dry matter, protein, pH24, meat colour (L*, a*, and b*), drip loss, and cooking loss were not affected by dietary treatment or sex. The addition of OEO or CAO to the diets did not change the meat lipid oxidation or sensory quality characteristics at different storage times. However, meat from the female lambs was found to have thiobarbituric acid reactive substances (TBARS) values lower than that of the meat from the male lambs after 2 d and 4 d of storage. However, the female lamb meat was more preferred in terms of flavour and general acceptance. The ΣMUFA, ΣPUFA, ΣUFA, Σn-6, Σn-3, and Σn-6/Σn-3 contents of the lamb meat were not affected by the dietary treatment. As a result, the inclusion of 300 mg of oregano essential oil/kg of DM in lamb diets is considered appropriate because of its significant contributions to the fat composition of lamb meat.

Effects of supplementing sweet sorghum with grapeseeds on carcass parameters, and meat quality, amino acid, and fatty acid composition of lambs.

Sweet sorghum is an important forage crop for ruminants, especially in low rainfall areas. Grapeseeds are an abundant by-product of wine-making and contain bioactive substances that can improve the antioxidant capacity of meat. We examined the effect of sweet sorghum forage with supplementary grapeseeds on carcass and meat quality in lambs. Twenty-eight Small-tailed Han lambs (body weight = 19.1±1.20 kg), aged 3 to 4 months, were penned, and fed individually. The lambs were divided into four groups (n = 7 each) and were offered one of four diets: i) sweet sorghum silage; ii) sweet sorghum silage + grapeseeds; iii) sweet sorghum hay; and iv) sweet sorghum hay + grapeseeds. The grapeseeds were added to the concentrate at 6% DM and the diets were fed for 100 d. Sweet sorghum silage tended (p = 0.068) to increase hot carcass weight, while grapeseeds tended (p = 0.081) to decrease dressing percentage without affecting other carcass parameters. Lambs consuming supplementary grapeseeds increased (p<0.05) meat redness and tended to decrease (p = 0.075) concentration of methionine in meat. Lambs consuming sweet sorghum silage increased (p<0.001) water content of the meat and had a lower (p<0.05) concentration of n-6 polyunsaturated fatty acids (PUFA) and n-6:n-3 PUFA ratio than lambs consuming sweet sorghum hay. Saturated fatty acids content in meat was lowest (p<0.05) in lambs consuming sweet sorghum silage with grapeseeds. Lambs with supplementary grapeseeds tended (p<0.10) to increase eicosapentaenoic acid and docosahexaenoic acid and have a lower thrombogenic index than lambs not consuming grapeseeds. It was concluded that sweet sorghum with supplementary grapeseeds fed to lambs; i) improved the color of the meat to be more appetizing to the consumer; ii) tended to improve the fatty acids composition of the meat; and iii) lowered thrombogenic index of the meat.

Effect of Dietary Inclusion of Azadirachta indica and Moringa oleifera Leaf Extracts on the Carcass Quality and Fatty Acid Composition of Lambs Fed High Forage Total Mixed Rations.

Simple SummaryFeed additives based on medicinal plants, such as neem and moringa plant extracts, are used to mitigate rumen methane emissions, but data regarding their effects on lamb meat quality are scarce. This study investigated the effects of oral supplementation of neem and moringa leaf extracts on the carcass quality and meat fatty acid composition of lambs. Neem leaf extracts had no effect on carcass fat and meat fatty acid composition. Whereas, Moringa leaf extract improved the meat fatty acid composition of lambs compared to the monensin treatment. There is an increased interest in the use of medicinal plants as alternatives to antibiotic growth promoters and as agents for methane production mitigation. This study investigated the effects of Azadirachta indica and Moringa oleifera feed additives on the carcass and meat quality of lambs. Forty South African Mutton Merino lambs, weighing between 29 and 43 kg, were randomly assigned to four treatment groups (n = 10 lambs/treatment) and fed a basal total mixed ration (TMR) containing soybean meal (17%), yellow maize (28%), Alfalfa hay (20%), Eragrostis curvula hay (22.2%), molasses (6.0%), wheat offal (5%), urea (0.8%) and vitamin premix (0.5%) on a DM basis. The dietary treatments: TMR diet (control); TMR diet with A. indica leaf extract (A. indica leaf extract at a dosage of 50 mg per kg of feed: neem); TMR diet with M. oleifera leaf extract (M. oleifera leaf extract at a dosage of 50 mg per kg DM of feed: moringa); TMR diet with monensin (at a dosage of 50 mg monensin sodium per kg of feed: positive control). After an adaptation period of 10 days to the experimental conditions, the lambs from all treatment groups were fed ad libitum with the experimental diets. The lambs were slaughtered at a live weight of 60–65 kg after a 23 week trial period. The plant extract dietary additives had no significant effects on the carcass characteristics of the lambs. In comparison to monensin, supplementing with moringa leaf extracts resulted in a higher proportion of C18:1n9c (45.0% ± 0.57 vs. 40.5% ± 0.80; p < 0.05), total MUFAs (47.3% ± 0.66 vs. 42.6% ± 0.87; p < 0.05), and UFA:SFA ratio (1.01 ± 0.03 vs. 0.85 ± 0.03; p < 0.05), which may be beneficial for human health. Our results suggest that natural feed additives, such as A. indica and M. oleifera leaf extracts, can be included in lamb diets without compromising meat fatty acid composition. The negative economic impacts of such technologies on animal production and farm profitability should not be expected.

Effects of palm oil supplementation and fibrolytic enzymes in high forage diets on growth, carcass characteristics and fatty acid profiles of lambs

This study investigated the effects of palm oil and fibrolytic enzyme supplementation in high forage diets on growth, carcass characteristics and fatty acid composition of lambs. Forty South African Mutton Merino ram lambs were randomly assigned to four treatment groups (n = 10 lambs/ treatment) and fed a basal total mixed ration (TMR). The treatments were: TMR diet with Megalac as bypass oil (control); TMR diet supplemented with 3% palm oil; TMR diet with cellulase and xylanase enzymes and TMR diet supplemented with 3% palm oil and cellulase and xylanase enzymes. The lambs were slaughtered at a target weight of about 42 kg. Palm oil supplementation resulted in a longer feeding period (P < 0.05) and lower dressing percentage (P < 0.01), but the carcasses had higher meat yield (P < 0.01) and lower fat content (P < 0.05) compared to the other treatment groups. Additionally, palm oil supplementation increased the proportion of C18:0 (P < 0.05) while decreasing (P < 0.05) the proportion of C14:0 (P < 0.05) and C16:0 (P < 0.05) in fat depots, which may be beneficial for human health. The fibrolytic enzyme treatment had minimal effects on growth, carcass characteristics, meat quality and fatty acid composition of lambs. The interaction effect of palm oil and fibrolytic enzymes had positive effects on the UFA: SFA ratio due to an increase (P < 0.05) in C20:3n6 and C20:4n6 and a reduction (P < 0.05) in saturated fatty acids. The results suggest that methane mitigation strategies through palm oil and enzyme supplementation can be used in lamb diets without adverse effects on product quality.

PSXIV-17 Meat quality and fatty acid composition of lambs reared under thermal stress in grazing conditions and slaughtered at two body weights

Abstract Interest in meat quality and its fatty acid composition stems mainly from the need to find ways to produce healthier meat. In Puerto Rico, no documented information is available on the nutritional profile in the meat of lambs raised under local conditions (crossbred animals raised in heat stress and grazing naturalized pastures, NP). The quality of meat and fatty acid composition was evaluated, of 12 lambs grazed NP &amp;gt; 8h, tropical grass hay and water ad libitum, 150g of concentrate (12% CP), and mineral blocks. Six animals were slaughtered at two live weight of 22 (SW1) or 35 (SW2) kg to determine the meat quality given by pH, color, nutrient content, and the fatty acid composition in the Longissimus dorsi muscle. The data was analyzed using a completely randomized design with two treatments and six repetitions. SW1 and SW2 had similar pH (5.57 vs. 5.73), but lambs at SW1 displayed lower (P &amp;lt; 0.01) a* value than those slaughtered at SW2 (11.18 vs 13.57), but L* (38.91 vs 37.56) and b* (10.72 vs 10.67) values were similar. On both slaughter weight moisture (75.63 vs 74.51), ash (4.10 vs 3.34), crude protein (24.36 vs 25.12), and crude fat (2.30 vs 2.01) percentage of the meat was similar. The total lipid content (0.953 vs 2.25), saturated fatty acids (34.68 vs 42.98), and monounsaturated fatty acid (28.36 vs 37.28) of lambs at SW1 was lower than those at SW2, but n-6 and n-3 polyunsaturated fatty acids (18.74 vs 8.57and 6.61 vs 2.88, respectively) were higher (P &amp;lt; 0.05). The n-6/n-3 ratio was similar for both SW groups (2.84 vs 2.96). Differences in individual fatty acid content due to the slaughter weight were observed. In conclusion, the meat quality and the fatty acid composition of the Longissimus dorsi were affected by slaughter weight of lambs grazing naturalized pastures.

Polymorphism and Expression of HSD17β13 Gene and Its Association with Lamb Quality of Indonesian Sheep

HSD17β13 (17beta 13-Hydroxysteroid dehydrogenases) are important enzymes in steroid metabolism. This study investigated the polymorphisms and expression of the HSD17β13 gene in lamb quality traits in Indonesian sheep. A total of 200 of rams of seven breeds administered in the study were Javanese fat-tailed (JFT), Javanese thin-tailed (JTT), Garut sheep (GS), Jonggol sheep (JS), Garut composite sheep (GCS), Compass agrinac sheep (CAS), Barbados cross sheep (BCS) aged 10-12 months and weighed 20-30 kg. The Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) and MspI enzyme restriction were performed to identify the polymorphism of the HSD17β13 gene. The lamb quality traits were measured for physical quality, flavor, odor, and fatty acid composition. The results showed that the HSD17β13 gene was polymorphic and had three genotypes i.e., CC, CT, and TT. The highest genotype frequency was the CC when compared to the other genotypes. The allele frequency of HSD17β13 gene was not in Hardy Weinberg Equilibrium. The polymorphism of HSD17β13 gene was significantly (P&lt;0.05) associated with the fatty acid composition and Saturated Fatty Acid (SFA), i.e., tridecanoic acid (C13:0), arachidic acid (C20:0), henecosanoic acid (C21:0), and tricosanoic acid (C23:0). The polymorphism was also significantly associated with the Monounsaturated Fatty Acid (MUFA) i.e. ginkgoleic acid (C17:1) and nervonoic acid (C24:1), and Polyunsaturated Fatty Acid (PUFA) i.e. eicosedienoic acid (C20:2). The level of expression of the HSD17β13 gene based on quantitative real time-PCR analysis results was not significantly different (P&gt;0.05) among genotypes for lamb quality traits. It can be concluded that the polymorphism of HSD17β13 gene was associated with the fatty acid composition of lamb in Indonesian sheep.

The effect of using diet supplementation based on argane (Argania spinosa) on fattening performance, carcass characteristics and fatty acid composition of lambs

The current study was performed in order to evaluate the effect of using argane by-products (oil cake and pulp) as fattening diet of lambs. This was achieved through an experimental lamb fattening investigation using argan by-product as feeding source and the exploration of the fattened lamb performance, carcass characteristics and the chemical fatty acid composition of the quality produced meat.Twenty fattening Sardi lambs (26 ± 0.5 kg body weight and six months old) were divided into two (n = 10) homogenous experimental and control groups. Argane by-products (ABP) and traditional (CF) diets have been used for feeding the experimental and control groups respectively during a period of 75 days. The results obtained for both groups were used to determine the effect of feeding argane by-products on animal weight, average daily gain (ADG), carcass weight, muscle pH values, dressing %, dry matter, ash, ether extract, crude fiber, crude protein, and fatty acid composition.The obtained results showed that the experimental ABP group lambs had higher average daily gain and meat chemical, crude protein and ash and proportion of C18:0 than the control CF group lambs, while the control CF group had a higher feed conversion ratio, ether extract, mesenteric and perirenal fat. The results obtained for pH0 and pH24 were similar for both explored groups. The obtained results showed thus that the use of ABP as a diet to fattening lambs increased their performance and lean meat yield.

Effect of weaning and sex on meat fatty acid profile of grazing lambs

Article Details: Received: 2020-10-20 | Accepted: 2020-11-27 | Available online: 2021-01-31 https://doi.org/10.15414/afz.2021.24.mi-prap.25-28 Twenty Tsigai and Suffolk crossbreed lambs in grazing conditions were used to investigate the effect of weaning status (weaned vs. unweaned) and sex on fatty acid composition of meat. Six males and four females were included in both groups, the weaned lambs group (WL) and the unweaned lambs group (UL). The fatty acid profile of Musculus longissimus lumborum et thoracis intramuscular fat (IMF) were determined by gas chromatography and analysed by analysis of variance. WL displayed higher proportion of t 11-C18:1 (P < 0.001), n-6 polyunsaturated fatty acid (PUFA) C18:2 (P < 0.01) and C20:4 (P < 0.05), n-3 PUFA C18:3 (P < 0.05), C20:5 (P < 0.01), C22:5 (P < 0.05), C22:6 (P < 0.05) and the total PUFA (P < 0.01) in IMF than UL. On the contrary, IMF of UL had higher proportion of the medium-chain saturated fatty acids (SFA) such as C12:0 (P < 0.01), C14:0 (P < 0.01) and C16:0 (P < 0.01), the total SFA (P < 0.05) and the total monounsaturated fatty acids (MUFA) (P < 0.05). The weaning status had no significant effect on n-6/n-3 ratio, however the ratio was satisfactory low in both groups. The sex had no effect on a profile of essential and health beneficial fatty acids in meat of lamb. In conclusion, meat of weaned lambs in grazing system might be considered to obtain a higher proportion of healthy n-3 fatty acids compared to unweaned lambs. Keywords: fatty acids, intramuscular fat, lamb meat, weaned lambs, unweaned lambs References Belanche, A. et al. (2019). Amulti-kingdom study reveals the plasticity of the rumen microbiota in response to a shift from non-grazing to grazing diets in sheep. Frontiers in Microbiology , 10, 1-17. Doi: https://doi.org/10.3389/fmicb.2019.00122 Caneque, V. et al. (2001). Effect of weaning age and slaughter weight on carcass and meat quality of Talaverana breed lambs raised at pasture. Animal Science , 73, 85-95. Cividini, A. et al. (2014). Fatty acid composition of lamb meat from the autochthonous Jezersko-Solcava breed reared in different production systems. Meat Science , 97(4), 480-485. Doi: https://doi.org/10.1016/j.meatsci.2013.12.012 Cividini, A. et al. (2008). Fatty acid composition of lamb meat as affected by production system, weaning and sex. Acta Agriculturae Slovenica , Suplement 2, 47-52. De Brito, G. F. et al. (2017). TheEfect of Extensive Feeding Systems on Growth Rate, Carcass Traits, and Meat Quality of Finishing Lambs. Comprehensive Reviews. Food Science and Food Safety . 16(1), 23-38. Doi: https://doi.org/10.1111/1541-4337.12230 Enser, M. et al. (1998). Fatty acid content and composition of UK beef and lamb muscle in relation to production systemand implications for human nutrition. Meat Science ., 49, 329–341. French, P. et al. (2000). Fatty acid composition, including conjugated linoleic acid, of intramuscular fat from steers offered grazed grass, grass silage, or concentrate-based diets. Journal of Animal Science , 78, 2849-2855. Howes, N. L. (2015). Opportunities and Implications of Pasture-Based Lamb Fattening to Enhance the Long-Chain Fatty Acid Composition in Meat. Comprehensive Reviews in Food Science and Food Safety , 14(1), 22-36. Doi: https://doi.org/10.1111/1541-4337.12118 Jacques, J. et al. (2016). Meat quality, organoleptic characteristics, and fatty acid composition of Dorset lambs fed different forage to concentrate ratios or fresh grass. Canadian Journal of Animal Science , 97, 290-301.Doi: https://doi.org/10.1139/cjas-2016-0104 Kosulwat, S. et al. (2003). Lipid composition of Australian retail lamb cuts with differing carcass classification characteristics. Meat Science , 65, 1413-1420. Margetin, M. et al. (2018). Fatty acids in intramuscular fat of Ile de France lambs in two different production Systems. Archives Animal Breeding , 61 (4), 395-403. Doi: https://doi.org/10.5194/aab-61-395-2018 Velasco, S et al. (2004). Effect of different feeds on meat quality and fatty acid composition of lambs fattened at pasture. Meat Science , 66(2), 457-465. Doi: https://doi.org/10.1016/S0309-1740(03)00134-7 Velasco, S. et al. (2001) Fatty acid composition of adipose depots of suckling lambs raised under different production systems. Meat Science , 59(3), 325-333. Velasco, S. et al. (2000). Carcass and meat quality of Talaverana breed sucking lambs in relation to gender and slaughter weight . Animal Science , 70, 253-263. Woods, V. B., &Fearon, A. M. (2009). Dietary sources of unsaturated fatty acids for animals and their transfer into meat, milk and eggs: A review. Livestock Science , 126, 1-20.

The effect of dietary dry distilled rose petals or dihydroquercetin supplementation on the oxidative stability and quality of lamb muscles and fat.

Abstract The objective of this study was to determine the changes in the quality of m. Longissimus dorsi and m. Semimembranosus and perirenal adipose tissue from lambs fed a diet supplemented by 7.5 mg dihydroquercetin/kg/day or 545 mg dry distilled rose petals (DDRP)/kg/d. The experiments were performed with 30 male lambs aged 65 days. They were divided into three groups of 10 animals fed 50 days ad libitum: control group (with ground alfalfa + granulated compound feed) and two experimental ones (with the same diet + phytonutrients). Samples stored for 1 and 7 days at 2 ± 2°C were examined. After 7 d of storage, the addition of 545 mg DDRP/kg/d contributed to a decrease in pH by 2-6% in both types of tissues and reduced the accumulation of α-aminoacidic nitrogen by 7-14% and TBARS by more than 20% in both muscles tested. The lambs' diet supplementation with both phytonutrients led to a reduction in the aerobic plate count and total combined yeasts and molds count. The addition of dihydroquercetin was found to be responsible for the reduction of FFA and the total color difference as well as for approx. a 5% increasing the amount of monounsaturated fatty acids. This influence is more pronounced in m. Longissimus dorsi . Further studies are needed to determine whether the application of higher doses of DDRP and dihydroquercetin as dietary supplements in lambs will provoke a more pronounced inhibitory effect on lipid oxidation and the fatty acid composition of lamb and fats.

Effect of production system on fatty acid composition in subcutaneous adipose tissue of Ile de France lambs

Effect of production system on fatty acid composition in subcutaneous adipose tissue of Ile de France lambs

Effect of selected plant species within biodiverse pasture on in vitro fatty acid biohydrogenation and tissue fatty acid composition of lamb

The effect of botanical diversity on supply of polyunsaturated fatty acids (PUFA) to ruminants in vitro, and the fatty acid (FA) composition of muscle in lambs was investigated. Six plant species, commonly grown as part of UK herbal ley mixtures (Trifolium pratense, Lotus corniculatus, Achillea millefolium, Centaurea nigra, Plantago lanceolata and Prunella vulgaris), were assessed for FA profile, and in vitro biohydrogenation of constituent PUFA, to estimate intestinal supply of PUFA available for absorption by ruminants. Modelling the in vitro data suggested that L. corniculatus and P. vulgaris had the greatest potential to increase 18:3n-3 supply to ruminants, having the highest amounts escaping in vitro biohydrogenation. Biodiverse pastures were established using the six selected species, under-sown in a perennial ryegrass-based sward. Lambs were grazed (~50 days) on biodiverse or control pastures and the effects on the FA composition of musculus longissimus thoracis (lean and subcutaneous fat) and musculus semimembranosus (lean) were determined. Biodiverse pasture increased 18:2n-6 and 18:3n-3 contents of m. semimembranosus (+14.8 and +7.2 mg/100 g tissue, respectively) and the subcutaneous fat of m. longissimus thoracis (+158 and +166 mg/100 g tissue, respectively) relative to feeding a perennial ryegrass pasture. However, there was no effect on total concentrations of saturated FA in the tissues studied. It was concluded that enhancing biodiversity had a positive impact on muscle FA profile reflected by increased levels of total PUFA.

Effect of supplementation with linseed or a blend of aromatic spices and time on feed on fatty acid composition, meat quality and consumer liking of meat from lambs fed dehydrated alfalfa or corn

Cross-bred lambs (n=72) were fed finishing diets using a factorial arrangement of treatments: BASAL DIET (alfalfa pellets or corn), SUPPLEMENT (none, linseed or aromatic spices), TIME ON FEED (41 or 83days). Carcass and meat quality traits, fatty acid composition, color stability and consumer liking were determined. Feeding alfalfa improved sensory ratings and fatty acid composition of lamb. However, corn or longer alfalfa feeding would be recommended if heavier and fatter carcasses are sought. Consumer liking and fatty acid composition of lamb were improved with addition of spices and linseed, respectively. But additional antioxidant strategies should be considered to delay meat color deterioration during storage if lambs are fed corn-linseed for 83days. Although alfalfa basal diet and linseed supplementation improved fatty acid composition, feeding the basal diets for at least 41days resulted in low n-3 fatty acid concentrations in muscle.

Characterization of the fatty acid composition of lamb commercially available in northern Spain: Emphasis on the trans-18:1 and CLA content and profile

A survey of commercially available lamb meat was performed in northern Spain in order to evaluate their fatty acid (FA) composition with emphasis on trans fatty acid (TFA) and conjugated linoleic acid (CLA) isomers. Samples were collected in spring (n=24) and winter (n=24) of 2013, and were obtained in about equal numbers from grocery stores and butcher-shops. Subcutaneous fat, known to be a sensitive indicator of TFA content in ruminants, was analyzed by GC-FID. In general, very few differences were observed between collection periods and type of stores because of the high variability within the groups that was believed to be associated with differences in genetics and feeding strategies. However, the 10t/11t ratio of all samples showed two clearly identifiable groups irrespective of the source: 1) when 10t/11t was >1, 10t-shifted samples; 2) when 10t/11t was ≤1, non-shifted samples where 11t-18:1 was the predominant isomer. These two groups were clearly identified and associated with distinct FAs using principal component analysis.

The effect of feeding system on slaughter-carcass characteristics, meat quality, and fatty acid composition of lambs

Abstract. In this study, we aimed to determine the slaughter-carcass characteristics, meat quality, and fatty acid composition in lambs raised under intensive and extensive conditions. The animal material consisted of 30 Norduz male lambs, with an average age of 171 days. The lambs were divided into two groups: concentrate-fed lambs (CO) and pasture-fed lambs (PS). The results showed that the CO lambs had heavier carcasses (p&lt; 0.001), a higher dressing percentage (p&lt; 0.001), and higher intramuscular fat (p&lt; 0.01) than the PS lambs. It was determined that the longissimus thoracis muscle of the CO lambs had a lower ultimate pH and higher L* and water-holding capacity than the PS lambs. In this study, intramuscular fat (longissimus thoracis, semimembranosus, triceps brachii), subcutaneous and tail fat samples were used to evaluate the effect of feeding system on fatty acid composition. The polyunsaturated fatty acid to saturated fatty acid ratio (PUFA ∕ SFA) of intramuscular fat was found to be significantly higher in the CO group than in the PS lambs, while similar subcutaneous and tail fat results were found in both groups. Moreover, the PS lambs had a lower n6 ∕ n3 ratio and higher percentage of omega-3 than the CO lambs in all tissues studied (p&lt; 0.05). Overall, the CO lambs have heavier and fattier carcasses with better meat quality traits than the PS lambs. However, the effects of feeding system have varying results based on the fatty acid composition of different types of fat deposits.

Effect of Sodium Bicarbonate Supplementation on Fatty Acid Composition of Lambs Fed Concentrate Diets at Different Ambient Temperature Levels

The objective of this study was to evaluate the effect of ambient temperature and sodium bicarbonate (NaHCO₃) supplementation in diets for growing lambs on meat fatty acids composition. A slaughter study was carried out on 12 male Black Belly Barbados lambs randomly drawn from a prior growth trial (245 days). The lambs were divided into four equal groups and allotted in a 2�2 factorial design. The lambs were allotted at random to two dietary treatments of a basal diet (35: 65 roughage: concentrate) or basal diet supplemented with 4% NaHCO3 at different ambient temperatures (20 and 30�C) in an environment controlled chamber for 10 days. Lambs were slaughtered for carcass evaluation at about 262 days of age (245 days of growth trial, 7 days adaptation and 10 days of experimental period). Samples for fatty acids analysis were taken from the leg muscles and <em>longissimus dorsi</em> region (between the 12th and 13th rib). Ambient temperature influenced (p<0.05, p<0.01, p<0.001and p<0.05) C18:2t isomers, C20:4, C20:3 <em>n</em>-6 and C20:4 <em>n</em>-6 levels on the <em>longissimus dorsi</em> muscle, with higher C20:3 <em>n</em>-6 (p<0.001) but lower C20:4 <em>n</em>-6 (p<0.05) levels in lambs under the higher ambient temperature. The fatty acids C18:1c, C18:2t and C20:5 levels on the leg muscle were also significantly influenced (p<0.01, p<0.001 and p<0.01 resp.) by dietary treatments with higher levels in lambs fed NaHCO₃ diet. These results indicated that NaHCO₃ supplementation at low ambient temperatures significantly decreased fatty acids levels.

Effects of extruded linseed on muscle physicochemical characteristics and fatty acid composition of lambs

Effects of extruded linseed incorporation on meat quality and intramuscular fat fatty acids (FAs) composition were studied on 36 lambs from Tunisian local breed, Queue Fine de l'Ouest. All lambs were male with an average body weight of 21.3 kg at the beginning of the experiment. Animals were divided into three groups of 12 lambs each, receiving hay ad-libitum and one of three concentrates containing 0 (Control), 15 (L15) and 30 (L30) per cent of extruded linseed. At the end of the experiment which lasted for 85 days, all the lambs were slaughtered. Samples of longissimus dorsi muscle were taken for meat quality measurements and FA determination. No effects of linseed on lamb growth were observed. The cooking loss, meat pH and colour parameters were similar for all diets. Linseed supplementation increased protein content (p=0.07) and decreased fat content (p=0.06) in the meat. However, the intramuscular FA composition was affected by linseed supplementation. The polyunsaturated FA to saturated FA ratio (PUFA/SFA) was higher for L15 and L30 groups than for Control (p<0.01). The content of C18:3 and the sum of polyunsaturated FA (PUFA) were higher for L15 and L30 groups than for Control one (p<0.05). PUFA n−3 contents significantly increased with linseed incorporation (0.70, 3.56 and 3.26 for Control, L15 and L30, respectively). In contrast, n−6:n−3 ratio significantly decreased from 5.23 for Control to 0.71 and 1.1 for L15 and L30, respectively.

Slaughter characteristics, carcass quality and fatty acid composition of lambs under four different production systems

Forty five Kivircik lambs were used to investigate the effects of production system on lamb performance, carcass quality characteristics and on fatty acid composition of longissimus dorsi muscle. W-C lambs (n=12) were weaned between 45 and 60 days of age and then were finished with concentrates in the sheepfold until slaughter. During the finishing period, W-C lambs had free access to alfalfa hay and concentrate feed. W-G-S lambs (n=10) were weaned between 45 and 60 days of age and then grazed on pasture for 96 days and then wheat stubble until slaughter. UW-C lambs (n=11) were finished with ad libitum alfalfa hay and concentrate feed in the sheepfold and these lambs suckled their mothers until slaughter. Lambs of UW-G system (n=12) were kept together with the main-flock and were grazed on pasture in the day-time. During the night, UW-G lambs suckled their mothers in sheepfold. Target slaughter weight was assumed as 30kg. Mean finishing duration was 62 days, 147 days, 66 days and 98 days in lambs from W-C, W-G-S, UW-C and UW-G systems, respectively. Average daily gain during experiment was higher in W-C (207g) and UW-C (197g) lambs than W-G-S (87g) and UW-G lambs (131g). Cold carcass weight was 13.18, 12.10, 14.03 and 13.49kg, and cold dressing based on empty body weight was 53.45, 50.04, 56.45 and 53.82% in lambs from W-C, W-G-S, UW-C and UW-G systems, respectively. Carcass fatness parameters (omental and mesenteric fat percentage, back fat thickness, kidney knob and channel fat percentage and fat proportion in pelvic limb joint) in lambs of W-G-S system were lower than lambs in other production systems. W-G-S lambs also had higher lean proportion and lean/fat ratio in pelvic limb joint. UW-G lambs had lower carcass fatness and higher lean proportion in pelvic limb than lambs finished with concentrate feed (W-C and UW-C systems). Proportions of pelvic and thoracic limb joints were higher in grazed lambs than lambs of concentrate based systems. The proportion of fatty acids in intramuscular fat was similar across animals on all four feeding systems except for C14:0 and C18:0. The percentage of C14:0 was the highest in UW-C lambs while higher proportions of C18:0 were found in intramuscular fat of W-G-S lambs than those of weaned lambs fed concentrate and unweaned lambs. As a conclusion, weaning at 45–60 days of age for lambs fed concentrate in sheepfold should be considered by farmers, who aim to get ewe milk as an additional product without any disadvantages in lamb growth performance and carcass quality. Indigent farmers, who prefer the use of natural grasslands to produce high quality lamb carcasses, might consider pasture feeding with mother's milk without concentrate feed cost.

Dietary influence on the m. longissimus dorsi fatty acid composition of lambs in relation to protein source

Dietary lipid effect, as a consequence of protein supplement, on lamb m. longissimus dorsi fatty acid composition was investigated, with emphasis on biohydrogenation intermediates. Crossbred lambs (White Swedish Landrace×Texel) were fed a barley-based diet without (CON) or with protein supplements including peas (PEA), rapeseed cake (RC) or hempseed cake (HC). The HC diet resulted in the highest muscle 22:6n-3 proportion, with the RC diet being similar (P<0.05). Protein supplement did not affect the c9,t11 conjugated linoleic acid (CLA) proportion, however the HC diet increased some minor CLA isomers, including t10,c12 CLA (P<0.05). The t10-18:1 and total trans-18:1 were lowest for the RC diet (P<0.05), likely relating to rumen conditions and precursor availability. The saturated, monounsaturated and branched-chain fatty acids were largely unaffected by protein supplement. In conclusion, feeding the RC diet lowered the t10-18:1 and total trans-18:1 in meat, and modestly increased 22:6n-3 content. The direction of these changes would be beneficial, making the RC diet the preferred protein supplement; however the magnitude of the changes in the present experiment may not be sufficient to have an impact on human health.

Intramuscular fatty acid composition of lambs fed diets containing alternative protein sources

Thirty male Merinizzata italiana lambs were divided into three groups after weaning according to live weight. The diet of the three groups differed in the main protein source used in the concentrate, soybean meal for treatment SBM, faba bean for treatment FB and peas for treatment PEA. Lambs were fed ad libitum and slaughtered at about 160 days of age. Meat from the PEA group had higher proportions of the essential fatty acids C18:2 ω-6 and C18:3 ω-3 than from FB and SBM lambs and consequently its derivatives, C20:4 ω-6 and C20:5 ω-3 respectively, were higher in meat from PEA animals, compared to SBM and FB ones. The total n-3 fatty acids were highest in meat from PEA lambs and consequently PEA lambs showed a more favourable n-6/n-3 ratio. In conclusion the use of legume seeds such as peas in lamb diets positively affected intramuscular fatty acid composition.

Growth performances, carcasses parameters and meat fatty acid composition of lamb fed green oak acorns (Quercus ilex) based diet.

The aim of this experiment is to compare the effects of diets containing green oak acorns (GO) and barley (BL) on the growth performances, carcasses parameters and the composition in fatty acids of lambs. Two groups of five lambs each were fed, respectively, during 105 days with diets containing 50% of oaks acorns and 50% of barley. At the end of the test, the animals of the two diets expressed comparable body weights and weight gain. A significant difference (P < 0.05) was observed for the thickness of fat cover which is 3 mm for the BL group against 1.6 mm for GO group even if no significant difference was revealed concerning the output with slaughtering. The intramuscular lipids were significantly higher (P < 0.05) in the group of animals fed with GO diet compared to the BL diet (3.88 vs 2.83 g.100-1 g of muscle). Among the saturated fatty acids (SFA), the stearic acid significantly appeared in higher proportion (P < 0.05) in GO diet (20.8 vs 18.1%) whereas the palmitic acid is prevalent in the group of animals fed with the BL diet (25 vs 30%). For the polyunsaturated fatty acid (PUFA), no significant difference was observed between the two groups. The linoleic acid is prevalent among the PUFA of two groups without significant difference. The linolenic acid is higher in the animal fed BL. The n-6: n-3 ratio is higher in the BL group (8.9 vs 7.3). At the end, the low level of incorporation of PUFA in muscle of the lamb because of biohydrogenation, suggests us supplementing the diet by green grass.