Longissimus Dorsi Muscle Of Lambs Research Articles

Intramuscular vitamin A injection in newborn lambs enhances antioxidant capacity and improves meat quality.

Vitamin A (VA) and its metabolite, retinoic acid (RA) possess several biological functions. This report investigated whether neonatal intramuscular VA injection affected antioxidative activity and meat quality in longissimus dorsi (LD) muscle of lambs. Lambs were injected with 0 (control) or 7,500 IU VA palmitate into the biceps femoris muscle on day 2 after birth. At 3, 12, and 32 weeks of age, blood samples were collected in the jugular vein for serum levels of RA and muscle samples were collected in the biceps femoris for analysis of relative mRNA expression of enzyme contributors to retinoid metabolism. All animals were harvested at 32 weeks of age and muscle samples were collected to explore the role of VA on the meat quality and antioxidant capacity of lambs. Our results indicated that VA increased the redness, crude protein, and crude fat (p < 0.05), without affecting moisture, ash, and amino acid composition in LD muscle (p > 0.05). In addition, VA increased catalase (CAT) activity and decreased malondialdehyde (MDA) levels in LD muscle (p < 0.05). Meanwhile, greater levels of CAT and NRF2 mRNA and protein contents with VA treatment were observed in LD muscle (p < 0.05), partly explained by the increased level of RA (p < 0.05). Collectively, our findings indicated that VA injection at birth could improve lamb meat quality by elevating the redness, crude protein, crude fat, and antioxidative capacity in LD muscle of lambs.

Antioxidant capacity, lipid oxidation status and expression of specific selenoprotein mRNA in Longissimus dorsi muscle of lambs (Ovies aries) supplemented with supranutritional selenium

Selenium is known to play a key role in maintenance of redox status of tissues, immunity, reproduction, thyroid and muscle functions. The present investigation was carried out to understand the effect of supranutritional dietary Se supplementation on antioxidant capacity, lipid oxidation and expression of specific selenoprotein mRNA in Longissimus dorsi muscles of growing lambs. Twenty male lambs of 5–6 months of age were fed basal diet supplemented with 0.5, 1.5 or 4.5 ppm Se-yeast (organic Se) or without Se (control) for 90 days. The antioxidant capacity, lipid oxidation of meat during different days of storage and the mRNA expression of GPX1, GPX2, GPX3, TXNRD1, TXNRD3, DIO1, DIO2, DIO3, SEPP1, SEP15 and SEPW1 were studied in Longissimus dorsi muscles of sheep. The results indicated improvement in antioxidant status by supplementation of 1.5 and 4.5 ppm Se, and reduction in meat lipid oxidation status on day 0 without any further reduction after 3 and 7 days of storage in all the Se supplemented lambs. A selective change in expression of GPX2, GPX3, TXNRD1, DIO2, DIO3, SEPP1, SEP15 and SEPW1 mRNA was observed by supranutritional Se while GPX1, TXNRD3, DIO1 and expressions remained unaffected by supplementation. In conclusion, supranutritional Se supplementation in lambs increased antioxidant status, reduced lipid oxidation status with limited effect on oxidative stability of meat during storage and regulated Longissimus dorsi muscle selenoprotein mRNA expression differentially depending on the Se feeding levels. Our results thus provided new insights into the regulation of selenoprotein gene expression by supranutritional levels of dietary Se.

Effects of flavonoids from Allium mongolicum Regel as a dietary additive on meat quality and composition of fatty acids related to flavor in lambs

Sixty male Small-tailed Han sheep (initial body weight: 42.5 ± 4.1 kg) were assigned randomly and averagely into four groups to evaluate effects of flavonoids extracted from Allium mongolicum Regel (AMR) on meat quality and composition of fatty acids related to flavor in longissimus dorsi muscle of lambs. Lambs of four groups were fed a basal control diet (C), and basal diet + three different amounts of flavonoids extracted from the AMR; those were 11 mg kg−1 (Flav 11), 22 mg kg−1 (Flav 22), or 33 mg kg−1 (Flav 33), respectively. Dressing percentage, loin eye area, cooking loss, and pressing loss were affected by treatments (P &lt; 0.05). Percentage of intramuscular fat, the concentrations of eicosapentaenoic acid, C18:0, total saturated fatty acids, monounsaturated fatty acid, and 4-methyloctanoic acid in longissimus dorsi muscle were changed by treatments (P &lt; 0.05). Addition of AMR to diet improved the meat quality and had favorable effects on fatty acid composition related to meat flavor in longissimus dorsi muscle.

Fatty acid profiles of muscle, liver, heart and kidney of Australian prime lambs fed different polyunsaturated fatty acids enriched pellets in a feedlot system

We investigated the effect of various dietary polyunsaturated fatty acid (PUFA) sources on the fatty acid profiles of muscle, liver, heart and kidney of Australian prime lambs. Seventy-two White Suffolk x Corriedale first-cross lambs weaned at 6 months of age were randomly allocated to the following six treatments: (1) Control: Lucerne hay only; wheat-based pellets infused with 50 ml/kg dry matter (DM) of oil from (2) rice bran (RBO); (3) canola (CO); (4) rumen-protected (RPO), (5) flaxseed (FSO) and (6) safflower (SO) sources in a completely randomized experimental design. Lambs in CO, FSO, SO and RPO treatments achieved contents of eicosapentaenoic acid (EPA, 22:5n-3) plus docosahexaenoic acid (DHA, 22:6n-3) in the longissimus dorsi muscle ranging from 31.1 to 57.1 mg/135 g, over and above the 30 mg per standard serve (135 g) threshold for “source” claim under the Australian guidelines. There was no difference in n-3 LC-PUFA contents in longissimus dorsi muscle of lambs fed dietary oils of plant origin. The highest 18:3n-3 (ALA) contents achieved with FSO diet in the muscle, liver and heart were 45.6, 128.1 and 51.3 mg/100 g, respectively. Liver and kidney contained high contents of n-3 LC-PUFA (ranging from 306.7 to 598.2 mg/100 g and 134.0 to 300.4 mg/100 g, respectively), with all values readily exceeding the ‘good source’ status (60 mg per serve under Australian guidelines). The liver and kidney of PUFA fed lambs can be labelled as ‘good source’ of n-3 LC-PUFA based on EPA and DHA contents stipulated by the Food Standards of Australia and New Zealand guidelines. Therefore, if lamb consumers consider eating the liver and kidney as their dietary protein sources, they can adequately obtain the associated health benefits of n-3 LC-PUFA.

Effects of supplementation of rumen-protected choline on growth performance, meat quality and gene expression in longissimus dorsi muscle of lambs

This study determined the effects of rumen-protected choline (RPC) on growth performance, blood lipids, meat quality and expression of genes involved in fatty-acid metabolism in young lambs. A total of 24 Dorper × Hu lambs (about 20 kg body weight) were kept in individual pens and fed diets with 0%, 0.25%, 0.50% and 0.75% RPC for 60 d. Supplementation of 0.25% RPC increased average daily gain of lambs, whereas treatments had no significant effect on feed intake. The pH values of meat were increased at 0.25% RPC and both, dripping loss and shear force of meat, were significantly decreased in RPC-supplemented lambs. No significant changes were observed for dressing percentage and intramuscular fat. RPC supplementations had no significant effect on the concentrations of triglycerides and cholesterols in serum, but the concentration of high-density lipoprotein was decreased at 0.50% RPC and that of low-density lipoprotein was increased at 0.75% RPC. In m. longissimus dorsi, the expressions of cluster of differentiation 36 (CD36), acetyl-CoA carboxylase (ACC) and fatty-acid synthase (FASN) genes were increased at 0.25% RPC. Supplementation of 0.75% RPC increased the expressions of lipoprotein lipase (LPL) and FASN genes, decreased the expression of ACC gene and had no effect on CD36 gene. The results of this study showed that supplementation of 0.25% RPC could promote growth performance of lambs and improve meat quality. This may be mediated by effects on blood lipid profiles and the metabolism of fatty acids in skeleton muscles. However, the beneficial effects of 0.25% RPC supplementation need to be validated with a larger number of animals. Higher doses, particularly 0.75% RPC, showed adverse effects on live weight gain and ACC expression.

Camelina sativa affects the fatty acid contents in M. longissimus muscle of lambs

Ruminant diets supplemented with different sources of unsaturated fatty acids (UFA) may be effective for modulating the rumen biohydrogenation process as well as for de novo fatty acid synthesis in animal tissues. Such a supplementation may consequently improve the proportion of fatty acids in animal products. The obtained effect in animal products depends on the quantity and composition of dietary fat; particularly UFAs. This study illustrates the effect of diets in which two doses of Camelina sativa (100 and 200 g in concentrate dry matter, respectively) were given as the primary sources of UFAs. The study shows the effect on the fatty acid contents in longissimus dorsi muscle of lambs. Diets containing C. sativa led to higher contents of either C18:2 c9t11 or C18:2 t10c12 isomers in lamb muscle as well as an increase in vaccenic acid (VA), arachidonic acid (AA), eicosapentaenoic acid (EPA) and docosapentaenoic acid (DPA) contents. The results also indicated that the addition of C. sativa leads to a higher content of linoleic, oleic and alpha linolenic acids in lamb muscles.Practical applications: The results of this study showed favorable changes in the UFA contents in longissimus dorsi muscle of lambs. The changes were obtained by supplementing the diets of the lambs with C. sativa cake, the plant cultivated as a biodiesel source. Inclusion of C. sativa cake in the concentrate dry matter for lambs may allow animal products to obtain the nutritionally desired fatty acids. Consumption of enriched products may act as chemopreventive agents and counteract the development of some human diseases.

Determining the effect of the fat-tail and carcass weight on meat fatty acid composition of Iranian lambs

Fat-tailed sheep are widely distributed around the globe, probably because of their ability to adapt and endure harsh environmental conditions. Climate change and increasing demand for protein mean these animals are a vital part of our food chain. Despite this, little is known about the composition of their meat. The aim of our study was to investigate the effect of the fat-tail and carcass weight on chemical composition and fatty acid profile of Longissimus dorsi muscle of lambs. We compared sixty male lambs from three fat-tail weight classes (tailed, light fat-tailed, heavy fat-tailed) and two carcass weight ranges (6–13kg, designated light-LC; 13–21kg, designated moderate-MC). These lambs were randomly selected from a local flock grazed under standard commercial conditions in Mazandran, Iran. Our results showed that heavy fat-tailed (HF) lambs deposit less intramuscular fat than light fat tailed (LF) and tailed (T) lambs (p<0.05). Lambs with moderate carcasses (MC) weight, deposited more intramuscular fat compared with lambs which had low carcass weight (p<0.001). Polyunsaturated fatty acids (PUFA) are considered healthier than saturated fatty acids (SFA). LC lambs had higher PUFA:SFA and lower n-6:n-3PUFA ratio (p<0.001), than MC lambs. There were no significant differences in the fatty acid profile of lambs due to the different fat tail weights. In conclusion, lambs with higher carcasses weight and intramuscular fat, had higher levels of unfavorable fatty acids. However, changes in intramuscular fat did not affect the fatty acid profile of lambs with different tail weights.

Composição regional e centesimal da carcaça de cordeiros criados nos sistemas de produção orgânico e convencional

Este trabalho foi realizado para avaliar o rendimento dos cortes de carcaça, a área de olho-de-lombo, a composição centesimal e o perfil de ácidos graxos da carne proveniente de cordeiros submetidos aos sistemas de produção orgânico e convencional. Foram utilizados 48 animais Ile de France, com peso corporal médio de 15 kg, distribuídos em dois sistemas de produção, orgânica e convencional e abatidos aos 32 kg de peso corporal. Os sistemas de produção não influenciaram o peso nem o rendimento dos cortes de carcaça, entretanto o comprimento máximo do músculo longissimus dorsi dos cordeiros criados no sistema orgânico foi superior ao dos animais do sistema convencional, assim como a espessura máxima de gordura de cobertura. A profundidade máxima do músculo, a espessura mínima de gordura de cobertura e a área de olho-de-lombo não diferiram entre os tratamentos. Na composição centesimal do músculo longissimus dorsi, apenas a matéria mineral foi influenciada, pois foi menor nos animais do sistema orgânico em relação ao convencional. Para os parâmetros umidade, proteína bruta e gordura, não houve influência dos sistemas de produção. O perfil de ácidos graxos saturados e monoinsaturados não foi influenciado pelos sistemas de produção, entretanto o ácido graxo poliinsaturado C18:2 (linoleico) foi maior na carne dos cordeiros criados no sistema orgânico em comparação aos do sistema convencional. O peso e a porcentagem dos cortes da carcaça são semelhantes entre os cordeiros submetidos aos sistemas de produção orgânico e convencional. A carne daqueles criados no sistema orgânico apresenta maior largura máxima no músculo longissimus dorsi (medida A) e porcentagem do ácido graxo poliinsaturado linoleico e menor teor de matéria mineral.

Effect of sodium bentonite and vegetable oil blend supplementation on growth, carcass quality and intramuscular fatty acid composition of lambs

Abstract The effect of dietary sodium bentonite and a blend of sunflower and linseed oils at 1:2 (v/v) on growth, carcass and meat quality and fatty acid (FA) composition of longissimus dorsi muscle of lambs was studied. Thirty-two Merino Branco lambs with initial live weights (LW) of 16.2 ± 2.93 kg were divided according to a completely randomized experimental design within a 2 × 2 factorial arrangement of treatments in order to evaluate effects of the vegetable oil blend supplementation (0 g/kg versus 60 g/kg DM) and sodium bentonite inclusion in diets (0 g/kg versus 20 g/kg DM). The basal diet consisted of pellets with 750 g dehydrated lucerne/kg DM and 250 g manioc/kg DM. The experimental period was 6 weeks. Bentonite affected neither daily LW gain, dry matter (DM) intake, nor carcass composition. However, bentonite decreased the a* meat colour parameter (redness; P =0.004). Oil supplementation affected neither daily LW gain, nor DM intake. However, it increased fat proportion in chump and shoulder cuts ( P P P P P =0.007), mostly by increasing proportions of n -3 PUFA and biohydrogenation derived PUFA. Oil supplementation decreased n -6 long chain PUFA ( P n -3 long chain PUFA was not affected by oil supplementation, so the increase in n -3 PUFA from 1.99 g/100 g of total FA to 4.23 g/100 g of total FA ( P P n -3 long chain PUFA concentration from 20 to 31 mg ( P cis -11 18:1 which decreased, and cis -13 18:1 and trans -8, cis -10 18:2 which were unchanged. Conjugated linoleic acid increased with oil supplementation from 0.50 to 1.72 g/100 g of total FA ( P trans -11 18:1, but prevented the increase of trans -10 18:1 in meat from oil supplemented lambs ( P Trans -11, cis -15 18:2, cis -9, cis -15 18:2 and cis -9, trans -11, cis -15 18:3 increased with dietary bentonite inclusion.