Softness and fatty acid composition of subcutaneous adipose tissue, and methylmalonic acid concentrations in the plasma of intensively reared lambs

Bioactivity and health effects of ruminant meat lipids. Invited Review

Ruminant meat (RM) is an excellent source of high-quality protein, B vitamins and trace minerals and plays an important role in global food and nutrition security. However, nutritional guidelines commonly recommend reduced intake of RM mainly because of its high saturated fatty acid (SFA) content, and more recently because of its perceived negative environmental impacts. RM is, however, rich in heart healthy cis-monounsaturated fatty acids and can be an important source of long-chain omega-3 (n-3) fatty acids in populations with low fish consumption. In addition, RM is a source of bioactive phospholipids, as well as rumen-derived bioactive fatty acids including branched-chain, vaccenic and rumenic acids, which have been associated with several health benefits. However, the role of bioactive RM lipids in maintaining and improving consumers' health have been generally ignored in nutritional guidelines. The present review examines RM lipids in relation to human health, and evaluates the effectiveness of different feeding strategies and possibilities for future profile and content improvement.

Effect of dietary neutral detergent fibre source on lambs growth, meat quality and biohydrogenation intermediates

With this trial we have tested the effects of structural and chemical composition of neutral detergent fibre (NDF) of the diet on lamb fatty acid composition of meat and subcutaneous fat. Twenty lambs, were fed complete diets with low starch and similar NDF content of different origin (ground alfalfa or soybean hulls). Animal performance and product quality were not affected by treatments. Rumen pH increased and parakeratosis intensity decreased with the level of alfalfa in the diet. Increasing the alfalfa proportion in the diet decreased t10-18:1 (P = .023), increased t11-18:1 (P = .003) and decreased the t10/t11 ratio according to a quadratic pattern (P = .020). Chemical composition and structure of the diet's fibrous fraction influenced the BI pattern of the final product. Forty percent of alfalfa in diet reduced the severity of t10-shift, but for its full resolution, other factors should be considered including forage particle size and buffering capacity of the diet.

Fatty Acid Composition of Muscle, Adipose Tissue and Liver from Muskoxen (Ovibos moschatus) Living in West Greenland

Information about lipid content and fatty acid (FA) composition of muskoxen (Ovibos moschatos) edible tissues is very limited in comparison to other meat sources. Thus, this work aims to present the first in-depth characterization of the FA profile of meat, subcutaneous adipose tissue and liver of muskoxen living in West Greenland. Furthermore, we aim to evaluate the effect of sex in the FA composition of these edible tissues. Samples from muscle (Longissimus dorsi), subcutaneous adipose tissue and liver were collected from female and male muskoxen, which were delivered at the butchery in Kangerlussuaq (West Greenland) during the winter hunting season. The lipid content of muscle, adipose tissue and liver averaged 284, 846 and 173 mg/g of dry tissue, respectively. This large lipid contents confirms that in late winter, when forage availability is scarce, muskoxen from West Greenland still have high fat reserves, demonstrating that they are well adapted to seasonal feed restriction. A detailed characterization of FA and dimethylacetal composition of muskoxen muscle, subcutaneous adipose tissue and liver showed that there are little differences on FA composition between sexes. Nevertheless, the 18:1cis-9 was the most abundant FA in muscle and adipose tissue, reaching 43% of total FA in muscle. The high content of 18:1cis-9 suggests that it can be selectively stored in muskoxen tissues. Regarding the nutritional composition of muskoxen edible tissues, they are not a good source of polyunsaturated FA; however, they may contribute to a higher fat intake. Information about the FA composition of muskoxen meat and liver is scarce, so this work can contribute to the characterization of the nutritional fat properties of muskoxen edible tissues and can be also useful to update food composition databases.

Does the fat tailed Damara ovine breed have a distinct lipid metabolism leading to a high concentration of branched chain fatty acids in tissues?

Fat tailed sheep breeds are known for their adaptation to nutritional stress, among other harsh production conditions. Damara sheep, native to Southern Africa, have recently been exported to other areas of the world, particularly Australia, aiming to produce lamb in semi-arid regions. Damaras have a unique hanging fat tail, a fat depot able to be mobilized under nutritional stress. In this article we perform an in-depth characterization of the fatty acid profiles of the fat tail in underfed and control Damara rams. Profiles were very similar between experimental groups, with the exception of palmitic acid (16:0) that was lower (P = 0.014) in underfed animals. However, the most striking result was the very high proportions of non-terminal branched chain fatty acids found in the fat tail adipose tissue, as well as the gastrocnemius muscle of Damara rams. The muscle of Dorper and Merino rams used in the same experiment did not present non-terminal branched chain fatty acids, suggesting that Damara rams have a unique lipid metabolism. Herein, we interpret this trait relating it to a higher ability of Damara sheep to digest fibrous fodder and to putative differences in the propionate metabolism by comparison to other sheep breeds.

The effect of maternal linseed supplementation and/or lamb linseed supplementation on muscle and subcutaneous adipose tissue fatty acid composition of indoor lambs

Eighty eight lambs were used in a 2×2 factorial arrangement 1) to investigate the effect of maternal dietary linseed supplementation and/or lamb linseed supplemented concentrate on growth performance, carcass fat quality and fatty acid (FA) composition of muscle and dorsal adipose tissue of indoor lambs 2) to study the relationships between subcutaneous fat quality and FA composition. Feeding linseed to ewes increased C18:3 n-3 (ALA) proportion in milk and therefore the ALA supply to suckling lambs. However, ALA and n-3 polyunsaturated FA (n-3 PUFA) proportions in lamb tissues were not affected. Feeding linseed to lambs during the post-weaning period significantly increased the proportions of ALA and n-3 PUFA in tissues. Softer and more colored fat was associated with a decrease in even medium-chain saturated FA and increases in odd and methyl FA proportions but not with ALA proportion in subcutaneous adipose tissue.

Feed intake, digestibility, and carcass characteristics of lambs fed a diet supplemented with soluble fibre

Thirty-six Merino lambs (8–9 weeks of age and 15.3 ± 0.13 kg of initial liveweight) were used to evaluate the effects of the inclusion of 120 g sugar beet pulp (replacing barley) and the addition of 20 g sodium bicarbonate per kg concentrate on feed intake, digestibility, animal performance and carcass characteristics in fattening lambs. Animals were housed individually and fed barley straw and the corresponding experimental concentrate feed ad libitum [basal diet composed of (g/kg) barley (500), maize (230), soybean meal (190), molasses (50) and vitamin premix (30)]. Faeces were collected for 5 days to estimate digestibility. Lambs were slaughtered when they reached 25 kg liveweight. Carcasses were chilled at 4°C for 24 h, some carcass dimensions were calculated, the left carcass was jointed into commercial cuts and shoulder tissue composition determined. Sugar beet pulp decreased DM intake (P < 0.05) and average daily gain (P < 0.001), increasing feed : gain ratio (P < 0.001), whereas sodium bicarbonate increased neutral detergent fibre digestibility (P < 0.05) and average daily gain, reducing the feed : gain ratio (P < 0.05). Carcass characteristics were not affected (P > 0.05) by either sodium bicarbonate or sugar beet pulp. Replacing barley with 120 g sugar beet pulp/kg concentrate caused a decrease in DM intake and average daily gain, resulting in an increase in feed : gain ratio, with no detrimental effect on carcass characteristics. The addition of 20 g sodium bicarbonate/kg concentrate improved intake and animal performance without affecting carcass characteristics. Inclusion of sugar beet pulp as a replacement for barley in high-concentrate diets for fattening lambs did not produce performance responses similar to those observed by adding a buffering salt.