Raw bovine meat fatty acids profile as an origin discriminator

Effects of green oak acorn (<i>Quercus ilex</i>) intake on nutrient digestibility, lamb growth, and carcass and non-carcass characteristics

Abstract. The green oak (Quercus ilex) plays an important role in forest ecology when oaks are the dominant species or are plentiful. The use of acorns as an alternative to barley for livestock feeding can be beneficial for breeders. The aim of this study was the evaluation of the acorn intake by lambs in two stages, suckling and fattening, on growth, diet digestibility, carcass and non-carcass characteristics. For this, 32 lambs were used. During the suckling period, 16 lambs were reared on range pasture, supplied by barley (S-Ba), the other 16 on forest pasture and supplied by acorns (S-Ac). During the fattening period, lambs were assigned to concentrate based either on barley (F-Ba) or acorn (F-Ac) resulting in eight animals per suckling treatment per fattening treatment. The feed intake, diet digestibility and lamb growth were recorded. At 90 d of fattening, all animals were slaughtered and carcass traits studied. The main results show that the incorporation of acorn in concentrate was without effect on digestibility of organic matter, crud protein and neutral detergent fibre. The nitrogen balance was positive for animals fed barley concentrate or acorn one (>8 g d−1). The lamb growth rates and slaughter body weight were not affected by acorn incorporation in both phases (p>0.05). Consequently, the carcass weights and carcass yields were similar. The F-Ac and S-Ac lambs had relatively heavier liver than F-Ba and S-Ba. The carcass composition in cutting pieces and that in tissues (muscle, fat and bone) was similar for all groups. These results suggest that acorns could replace partially conventional feedstuffs as concentrate without affecting animal performance and carcass quality.

Fatty acid metabolism in lambs supplemented with different condensed and hydrolysable tannin extracts

Five groups of lambs (n = 9 each) were used to test the effect of plant extracts rich in hydrolysable (HT) or condensed tannin (CT) on animal performance, fatty acid composition of rumen content, liver and meat. The control group (CO) received a concentrate-based diet without tannins supplementation. The other groups received the same diet as the control lambs plus 4% chestnut (CH) and tara (TA) extracts as a source of HT and mimosa (MI) and gambier (GA) extracts as a source of CT. One-way ANOVA was used to assess the overall effect of dietary treatments, tannins supplementation (CO vs. CH+TA+MI+GA) and the effect of tannin type (HT vs. CT: CH+TA vs. MI+GA) on animal performance, rumen content, liver and intramuscular FA. Dietary CH negatively affected animal performance. The rumen content of the different groups showed similar levels of 18:3 c9c12c15, 18:2 c9c12, 18:2 c9t11, 18:1 t11 and 18:0, whereas 18:1 t10 was greater in CO. Also, 18:1 t10 tended to be lower in the rumen of HT than CT-fed lambs. These data were partially confirmed in liver and meat, where CO showed a greater percentage of individual trans 18:1 fatty acids in comparison with tannins-fed groups. Our findings challenge some accepted generalizations on the use of tannins in ruminant diets as they were ineffective to favour the accumulation of dietary PUFA or healthy fatty acids of biohydrogenation origin in the rumen content and lamb meat, but suggest a generalized influence on BH rather than on specific steps.

Effects of grass- and concentrate-based finishing systems on the quality of meat from the M. longissimus thoracis of young Sarda bulls

Context Recent heightened interest of consumers in the origins of their food, together with broader general awareness of environmental matters, has led to an increase in the demand for meat obtained from grazing systems. The importance of local breeds adapted to medium- and low-input production is fully recognised as a means of guaranteeing the sustainability of these farming methods. A finishing system based on pastures and the use of local breeds could both meet the demands of consumers and increase economic returns for Sardinian farmers. Aims The work evaluated the effects of different finishing treatments (pasture PAS-0C vs hay–concentrate-based diets HAY-C) on the quality of meat from young Sarda bulls and the usefulness of meat chemicals as markers to discriminate between finishing systems. Methods Twenty-eight young Sarda bulls were assigned randomly to the following two treatments: finished on natural pasture (PAS-0C group, n = 7), and fed on natural pasture hay ad libitum and concentrate (HAY-C group, n = 21). The latter group comprised three levels characterised by an increasing daily dose of concentrates, as follows: 2.5 kg/animal (HAY-2.5C), 3.3 kg/animal (HAY-3.3C), and ad libitum (HAY-ALC). After slaughter at a fixed age (416 ± 25 days), carcass yield, pH of the Longissimus thoracis (LT) muscle, colour parameters, cooking loss, proximate analysis, α-tocopherol and cholesterol concentration, and fatty acid composition of intramuscular fat of LT were all determined. The discriminating power of the meat chemicals between the two main finishing systems (PAS-0C vs HAY-C) and among the three groups receiving concentrates and hay (HAY-2.5C, HAY-3.3C and HAY-ALC) was assessed using linear discriminant analysis. Key results Pasture-based treatment decreased the intramuscular fat and increased the α-tocopherol concentration of meat and the proportion of some desirable fatty acids (α-linolenic acid and its derivatives eicosapentaenoic acid, docosapentaenoic acid), and improved the value of the ratio of n-6:n-3, without affecting the ultimate pH, colour parameters, and cooking loss. The discriminant procedure was able to discriminate accurately between the two main finishing systems and among the three groups receiving concentrate and hay (P < 0.0001 and P < 0.005 of the Hotelling’s T-squared test respectively). The concentration of α-tocopherol was key to the discrimination of the two main finishing systems, whereas the content of C17:0 and C18:0i were particularly effective in discriminating among the three groups fed with hay concentrate. Conclusions Grazing improves some of the meat traits of young Sarda bulls compared with the effects of a hay-concentrate-based finishing diet. The concentration of α-tocopherol in meat is an effective marker for discriminating the effects of pasture from those of a concentrate-based finishing diet Implications The results highlight the role of pasture-based diet in finishing young Sarda bulls, and could provide a wealth of knowledge for Sardinian beef farmers for delivering meat produce that stands out in the market and meets the demand of consumers more concerned about food origin and its healthiness.

Technical note: Repeatability and reproducibility of curd yield and composition in a miniaturized coagulation model

Miniaturized coagulation (MC) models have been proposed for the evaluation of curd yield (CY) in individual milk samples of different dairy species and breeds, and for the analysis of cheese microstructure and texture. It is still unclear if MC using less than 50 mL of milk is suitable to evaluate CY and chemical composition, and if preservative added to raw milk may interfere with MC process. Therefore, this study aimed at evaluating repeatability and reproducibility of CY, curd moisture, and fat and protein content on curd dry matter (DM) from MC trials using 40 g of milk. Miniaturized coagulations were performed by 3 different operators on 3 consecutive days, using raw milk (RM) and raw milk added with preservative (RMP). Repeatability of CY, calculated as relative standard deviation on 6 miniaturized curds obtained within a day by the same operator, was below 5% for MC carried out with both RM and RMP. The Horwitz ratio, which is the ratio between measured and expected reproducibility, highlighted good reproducibility for CY from RM and fair reproducibility for CY from RMP. The same ratio highlighted lower accuracies for curd moisture and fat and protein content on curd DM, especially for MC trials carried out with RMP. The z-test was performed to evaluate the similarity between curds manufactured with RM and RMP in terms of average yield and chemical composition; z-scores did not highlight significant differences between values obtained from MC carried out with RM and RMP. It can be concluded that preservative had negligible effects on MC, giving the opportunity to extend milk physical and chemical stability, to schedule laboratory trials on longer time span, and to broaden the sample size within a batch of analyses.

Fatty acid profile as a discriminatory tool for the origin of lamb muscle and adipose tissue from different pastoral grazing areas in North Macedonia - A short communication

The fatty acid (FA) profiles of lamb muscle and adipose tissue originating from ten different grazing areas in North Macedonia and an assessment of whether the meat origin could be distinguished on the basis of FA profile are presented. Muscle and adipose tissues of three-month-old male lambs (crossbreds of autochthonous Ovcepolian and Württemberg) reared on spring pastures were studied. Statistically significant differences in the individual FA contents, FA groups and FA ratios were observed between lamb tissues from the different geographic regions. Canonical discriminant analysis showed there was a significant linear divergence between tissues from almost all examined regions. The greatest weight in the differentiation of the different areas showed fatty acid ratios, C18:3n3, C18:1n9c and C20:5n3 for the muscle tissue, as well as C18:1n9c, C18:2n6c, C16:1 and C17:1 for the adipose tissue. This showed that the FA composition of muscle and adipose tissue obtained from lambs reared on pasture could serve as a useful indicator to aid differentiation of its geographic origin but it should be confirmed through further replicated studies.

Fatty acid composition of young dairy bull beef as affected by breed type, production treatment, and relationship to sensory characteristics

The number of male calves from the Irish dairy herd has increased following the abolition of EU milk quotas in 2015. This is a new resource for the industry, and they can be reared economically to produce meat of acceptable eating quality with optimal fatty acid (FA) profile. The effects of breed and feeding treatment on the FA profile of the longissimus thoracis (LT) muscles of young dairy bulls (n = 69) of Holstein–Friesian and Jersey × Holstein–Friesian were evaluated. The relationship between FA composition and sensory characteristics was also investigated. Bulls were offered either 1 or 2 kg of concentrates at pasture during the first grazing season. Bulls finished on silage with 5 kg of concentrates or on ad libitum concentrates were slaughtered at 15 months of age, while bulls slaughtered at 19 months were fed either ad libitum pasture or pasture with 5 kg of concentrates during a second grazing season and finished on pasture with 5 kg of concentrates or ad libitum concentrates. Pasture-finished 19-month-old bulls had higher relative proportions of C18:0 (P < 0.001), C20:5n3 (eicosapentaenoic acid; P < 0.001), C18:2n6c (P < 0.05), C20:4n6 (P < 0.01), and total n-3 (P < 0.001) and n-6 polyunsaturated FAs (P < 0.05), but reduced C14:0, C16:0, C14:1, C16:1 and total monounsaturated FA (P < 0.001) proportions than in other production treatments. The silage-based finishing system of 15-month-old bulls increased the relative proportions of C15:0 (P < 0.01), C18:0 (P < 0.001) and total saturated FA (P < 0.01), but decreased the proportions of C20:3n6 (P < 0.05) and total unsaturated FA (P < 0.01) compared with the ad libitum-concentrate finishing system. However, the feeding system of the first or second grazing seasons had limited effects on the FA profile. Jersey × Holstein–Friesian breed type had higher relative proportions of C14:1 and C16:1 (P < 0.05), but lower C15:0 (P < 0.01), C17:0 (P < 0.001) and C17:1 (P < 0.01) proportions than did Holstein–Friesian beef. Slaughter age did not affect the FA profile. Monounsaturated FA, C14:0 and C16:0 proportions were positively (P < 0.05) correlated, but polyunsaturated FA proportion was negatively (P < 0.05) correlated with intramuscular fat content, sensory roast beef aroma, flavour, flavour length, juiciness, initial tenderness and ease of disintegration scores. Finishing system and slaughter weight were well discriminated on the basis of FA relative proportions by canonical discriminant analysis.

Meat provenance: Authentication of geographical origin and dietary background of meat

The authenticity of meat is now an important consideration in the multi-step food chain from production of animals on farm to consumer consumption of the final meat product. A range of techniques, involving analysis of elemental and molecular constituents of meat, fingerprint profiling and multivariate statistical analysis exists and these techniques are evolving in the quest to provide robust methods of establishing the dietary background of animals and the geographical origin of the meat derived from them. The potential application to meat authentication of techniques such as stable isotope ratio analysis applied to different animal tissues, measurement in meat of compounds directly derived from the diet of animals, such as fatty acids and fat soluble vitamins, and spectroscopy is explored. Challenges pertaining to the interpretation of data, as they relate to assignment of dietary background or geographical origin, are discussed.

Differentiation of geographical origin of cream products in Poland according to their fatty acid profile

Fatty acid (FA) composition of bovine milk fat from cream samples, originating from three regions of Poland (one mountainous and two lowland ones) and collected within 2 years, was analysed aiming at identifying the region of production by applying principal component analysis (PCA). From the 44 FAs identified by gas chromatography, two groups were discerned: seasonally variable (n=17) and non-seasonal (n=7). The biplots showed that different FAs could serve as markers of geographical origin of cream samples. The CLA, vaccenic acid, C18:39c12c15c, total C18:1 trans and C18:39c12c15c n-6 (GLA) were found indicative of mountainous regions, and the short-chain saturated FAs (SCFA; C4:0-C11:0) - of the lowland ones. The Opole province was characterised by a high content of linoleic acid. It was concluded that the origin of a cream sample could be fairly well identified by gas chromatography combined with chemometric analysis of milk fat FAs.

Fatty acid profile of three adipose depots in seven Spanish breeds of suckling kids

Intramuscular, subcutaneous and kidney knob fat depot fatty acid profiles were studied in 104 male suckling kids from seven Spanish breeds: Blanca Andaluza, Blanca Celtibérica, Moncaína, Negra Serrana-Castiza, Pirenaica, Malagueña and Murciano-Granadina. Kids were raised in the traditional production system on mother's milk and slaughtered at around 7kg live weight. Differences were observed between dairy (Malagueña) and meat breeds (Blanca Andaluza, Blanca Celtibérica, Moncaína, Negra Serrana-Castiza, and Pirenaica). Malagueña showed higher monounsaturated and conjugated linoleic fatty acid levels than the other breeds. Highest percentages of saturated fatty acids were observed in meat breeds. For intramuscular fat depot, the range for desirable fatty acids was 66.16-72.27% was. The influence of breed on fatty acid profiles of intramuscular, subcutaneous and kidney knob fat depots studied was evident. Intramuscular fat depot is proposed as a differentiating factor between dairy and meat breed goat kids, but not between meat breed kids.