Dietary guidelines for saturated fatty acids are not supported by the evidence

Metatranscriptomics reveals the effect of fermentation by Pediococcus acidilactici and Rhizopus oryzae on the quality of mutton sausages and the mechanism of odor metabolism

4-alkyl-branched chain fatty acids (vBCFAs) are key flavor-impact compounds in mutton and its derived products. Pediococcus acidilactici and Rhizopus oryzae were applied to ferment mutton sausages, and GC-MS/SIM and metatranscriptomics were employed to investigate the effects of different fermentation strategies on the quality of mutton sausages and the metabolism of 4-methyloctanoic acid (4-MOA) and 4-ethyloctanoic acid (4-EOA). The results demonstrated that inoculation with the mixed starter cultures exhibited lower pH, thiobarbituric acid, and peroxide values. Moreover, mixed starter cultures were more effective in reducing 4-MOA and 4-EOA compared to single starter culture and control. Metatranscriptomics revealed Streptococcus as the primary active genus in the mixed starter cultures. Additionally, we constructed the fermentation metabolic network of mutton sausages, demonstrating that mixed starter cultures effectively reduced 4-MOA and 4-EOA while enhancing sausages quality. The study provided a theoretical basis for improving the quality of mutton sausages.

Mixed methods evaluation of a low-carbohydrate high-fat nutrition education program for women from underserved communities in South Africa

South Africa faces a dual burden of non-communicable diseases (NCDs) and communicable diseases, exacerbated by the high consumption of processed foods. The Eat Better South Africa (EBSA) program implements community-based low-carbohydrate, high-fat (LCHF) interventions to address these issues. This study evaluated the impact of EBSA's 6-week program on the metabolic health and well-being of 32 women from underserved communities. It assessed outcomes before, immediately after, and six months post-intervention (n = 21). Quantitative findings showed significant improvements in key health markers. After six months, participants experienced an average weight loss of 5.6 kg (+- 5.5), a BMI reduction of 2 kg/m2, and a waist circumference decrease of 6.6 cm. Blood pressure dropped by 10.7 mmHg on average, and fasting glucose levels decreased significantly. Reductions were also observed in triglycerides and HbA1c, indicating better glycemic control. Liver function markers (GGT, ALT) and inflammation markers (CRP) improved as well. Qualitative analysis highlighted several key themes: participants were motivated by a desire to improve their health and lose weight but faced challenges such as social pressures, community violence, and scepticism about the diet's affordability and sustainability. Despite these barriers, positive experiences like increased energy and better hunger control were reported. Participants expressed the need for ongoing support to maintain these changes, both from the program and from their community. These findings suggest that LCHF diets can effectively manage metabolic conditions, but long-term adherence is challenged by socio-economic factors. The study highlights the importance of community-based interventions and highlights the need for further research to develop sustainable health strategies in low-income settings.

Effect of residual feed intake on meat quality in fattening Charolais bulls fed two contrasting diets

The selection of more efficient animals for breeding is of both economic and environmental interest to the industry. The aim of this study was to evaluate the influence of the animals' residual feed intake (RFI) ranking in interaction with the type of diet on the meat quality of Charolais beef cattle. Indeed, several biological mechanisms are associated with RFI, especially when animals are fed high starch-diets. It is therefore possible that quality parameters may show greater changes due to RFI in the context of high starch diets compared to high forage diets. An 84-day feed efficiency trial followed immediately by a second 112-day feed efficiency trial was conducted with a total of 100 animals fed either maize- or grass-diets for 196-days. At the end of the 84-day period, the 32 most divergent RFI animals (16 extreme RFI animals per diet, 8 RFI+ and 8 RFI-) were identified. They were slaughtered after 112-days of finishing. The Longissimus thoracis was characterised in terms of nutritional and sensory quality. RFI had no effect on lab colour, muscle shear force, total fat, fatty acid ratios and most of the total fatty acid content (especially n-3) irrespective of the diet. However, more efficient animals (RFI-) showed higher CLA contents compared to less efficient animals (RFI+) regardless of the diet and also a lower n6/n3 ratio only in animals fed the maize diets. Diet also had a significant effect on lipid and FA content as well as on FA composition.

Fatty Acid Profile and Thermal Behavior of Fat-Rich Edible Insect Oils Compared to Commonly Consumed Animal and Plant Oils

This study compared the physicochemical properties of edible insect oils from silkworm (Bombyx mori) pupa (SP), sago palm weevil (Rhynchophorus ferrugineus) larva (PW), and bamboo caterpillar (Omphisa fuscidentalis; BC) to oils from chicken skin (CK), beef back fat (BF), pork back fat (PF), salmon belly (SB), sea bass belly (BB), coconut (C), and peanut (P). The fatty acid profiles and thermal behaviors (crystallization and melting) of the extracted oils were evaluated. PW and BC oils had more saturated fatty acids (SFAs) than CK, PF, SB, BB, and P oils. SP oil had equivalent SFA content to CK and BB oils. Insect oils exhibited similar monounsaturated fatty acid concentrations in all samples, except C oils. PW and BC oils exhibited a higher content of palmitoleic acid than the other oils. SP oils contained polyunsaturated fatty acids similar to those in SB and BB oils, which were higher than those in PW, BC, CK, BF, and PF oils. SP oil also exhibited the highest concentration of α-linolenic acid (C18:3 n-3). Arachidonic acid (0.01-0.02 g/100 g) in all insect oils was lower level compared to CK, BF, PF, SB, and BB oils. SP oil (0.03 g/100 g) exhibited a slightly higher level of eicosapentaenoic acid compared to PW (0.01 g/100 g) and BC (0.01 g/100 g) oils. The insect oils were liquid at ambient temperature, solid below -15°C, and required less energy (△Hm-max) for melting than other samples. This study indicated that insects, particularly SP, could serve as an alternative source of fat to meet its growing demand.

Bioaccessibility of condensed tannins and their effect on the physico-chemical characteristics of lamb meat

The bioaccessibility of tannins as antioxidants in meat is essential to maximise their effectiveness in protecting the product. This property determines the amount of tannins available to interact with meat components, inhibiting lipid and protein oxidation and, consequently, prolonging shelf life and preserving the sensory quality of the product. The objective of this study was to evaluate the bioaccessibility of condensed tannins (CT) from Acacia mearnsii extract (AME) and their effect on the physico-chemical characteristics of fattened lamb meat. Thirty-six Dorset × Hampshire lambs (3 months old and 20.8 ± 3.3 kg live weight) were used. The lambs were distributed equally (n = 9) into four treatments: T1, T2, T3 and T4, which included a basal diet plus 0%, 0.25%, 0.5% and 0.75% of CT from AME, respectively. At the end of the fattening period, bioaccessibility was evaluated, the animals were slaughtered and a sample of the longissimus dorsi (LD) muscle was collected to assess colour, lipid oxidation, cooking weight loss and shear force on days 1, 4, 7 and 14 of shelf-life, in samples preserved at -20 °C. In addition, the long chain fatty acid profile was analysed. A completely randomised design was used, and the means were compared with Tukey's test (P < 0.05). The mean lightness (L*), yellowness (b*) and hue (H*) values were higher for T3 and T4. The addition of CT did not affect (P > 0.05) redness (a*), cooking weight loss (CWL) or shear force (SF). T4 decreased (P < 0.05) stearic acid and increased cis-9 trans-12 conjugated linoleic acid (CLA). Bioaccessibility was higher in the supplemented groups (T1 < T2, T3 and T4). In conclusion, supplementing CT from AME in the diet of lambs did not reduce lipid oxidation, but T3 or T4 improved some aspects of meat colour and CLA deposition.

ONE QUALITY concept: a narrative perspective to unravel nutritional challenges, controversies, and the imperative need of transforming our food systems

Ensuring a healthy and sustainable diet for all should be a global priority, and to achieve this goal the food system requires substantial changes. Adopting a one-size-fits-all approach is not feasible, and we need to consider the cultural particularities of each geography and not try to export models that work in one place but may be unsustainable in others. Our discussion will center on two key aspects within this overarching process: (a) the combination of a rigorous evidence-based approach with existing or proposed Nutritional Guidelines and policies required to realize the "ONE HEALTH" and "ONE QUALITY" concepts. Examining the Mediterranean diet and the latest findings on saturated fats will aid us in comprehending the necessary paradigm shift required to formulate new guidelines with substantial impact in preventing the rising prevalence of Non-Communicable Diseases worldwide; (b) the adequacy and scope of the data bank necessary to develop a global, science-based approach.

Inclusion of Sainfoin in the Concentrate of Finishing Lambs: Fatty Acid Profiles of Rumen, Plasma, and Muscle

The effects of sainfoin inclusion (Onobrychis viciifolia) in the finishing concentrate for light lambs on the fatty acid (FA) composition of the ruminal digesta, plasma, and meat were evaluated. Twenty-six weaned male lambs were divided into three groups and fed individually ad libitum for 40 days with one of three concentrates differing in the level of sainfoin inclusion: 0% (0SF), 20% (20SF), and 40% (40SF). The rumen digesta showed an increase in C18:3 n-3 concentration and a decrease in C18:1 t10 concentration when sainfoin was included in the concentrate regardless of the level of inclusion. However, the highest C18:1 t11 and the lowest C18:2 n-6 proportions were obtained only in the 40SF rumen, showing a stronger t11 biohydrogenation pathway. In plasma, most effects were associated with changes in the levels of polyunsaturated FA (PUFA) n-3. The meat FA profile of 40SF lambs presented higher percentages of PUFA n-3 and CLA c9,t11 and a lower PUFA n-6/PUFA n-3 ratio compared with those from 0SF and 20SF diets because of the potentiation of the ruminal t11 pathway. Inclusions of 20 and 40% sainfoin both showed beneficial effects on meat quality; furthermore, these effects were most marked in the 40% sainfoin diet.

Dietary Recommendations for Ethiopians on the Basis of Priority Diet-Related Diseases and Causes of Death in Ethiopia: An Umbrella Review

Food-based dietary guidelines (FBDG) need to be evidence-based. As part of the development of Ethiopian FBDG, we conducted an umbrella review to develop dietary recommendations. Protein-energy malnutrition (PEM), deficiencies of vitamin A, zinc, calcium, or folate, cardiovascular diseases (CVD), and type 2 diabetes mellitus (T2DM) were selected as a priority. Systematic reviews were eligible if they investigated the impact of foods, food groups, diet, or dietary patterns on priority diseases. After a search, 1513 articles were identified in PubMed, Scopus, and Google Scholar published from January 2014 to December 2021. The results showed that 19 out of 164 systematic reviews reported the impact of diet on PEM or micronutrient deficiencies. Daily 30-90 g whole-grain consumption reduces risk of CVD and T2DM. Pulses improve protein status, and consuming 50-150 g/d is associated with a reduced incidence of CVD and T2DM. Nuts are a good source of minerals, and consuming 15-35 g/d improves antioxidant status and is inversely associated with CVD risk. A daily intake of 200-300 mL of milk and dairy foods is a good source of calcium and contributes to bone mineral density. Limiting processed meat intake to <50 g/d reduces CVD risk. Fruits and vegetables are good sources of vitamins A and C. CVD and T2DM risks are reduced by consuming 200-300 g of vegetables plus fruits daily. Daily sugar consumption should be below 10% of total energy to lower risk of obesity, CVD, and T2DM. Plant-based fat has favorable nutrient profiles and modest saturated fat content. The association of saturated fatty acids with CVD and T2DM is inconclusive, but intake should be limited because of the low-density lipoprotein cholesterol-raising effect. Plant-based diets lower risk of CVD and T2DM but reduce micronutrient bioavailability. The review concludes with 9 key dietary recommendations proposed to be implemented in the Ethiopian FBDG. This review was registered at PROSPERO (CRD42019125490).

Fatty acid and oxidative shelf-life profiles of meat from lambs fed finisher diets containing Acacia mearnsii leaf-meal

Five diets containing Acacia mearnsii leaf-meal (AMLM; 0, 50, 100, 150 and 200 g/kg DM) substituted for Triticum aestivum bran were fed to lambs for 42 days. The effect of diet and retail display period on meat fatty acid (FA) composition (day 1); colour, antioxidant activity, myoglobin and lipid oxidation (day 1, 3, 5, 7 and 9); protein oxidation (1, 3 and 7 d) and instrumental tenderness (day 1, 5 and 10) were evaluated. Dietary AMLM linearly decreased (P ≤ 0.05) individual (14:0, 16:0, 18:0) and total saturated FA and increased (P ≤ 0.05) trans(t)-monounsaturated FA (MUFA) mainly t10/t11-18:1, individual and total conjugated linoleic acids, n-3 and n-6 polyunsaturated FA (PUFA) contents. The contents of cis(c)-MUFA, mainly c9-18:1, exhibited a quadratic response reaching a minimum at 50 g/kg AMLM (P ≤ 0.05). Meat antioxidant on day 9 was higher (P ≤ 0.05) for diets containing ≥100 g/kg DM AMLM compared to the other diet × retail display period interactions. Relative to the other interactions, meat redness values were lowest on day 7 and 9 for AMLM diets containing ≥150 g/kg DM (P ≤ 0.05). Dietary addition of AMLM increased (P ≤ 0.05) meat lightness and oxymyoglobin, and reduced (P ≤ 0.05) TBARS and instrumental tenderness values. However, oxymyoglobin values declined (P ≤ 0.05) over the retail display period, while lightness, metmyoglobin, TBARS and carbonyls increased (P ≤ 0.05). Results indicate that AMLM up to 200 g/kg DM in lamb finisher diets, improves meat fatty acid composition, tenderness, and lipid shelf-life.

Physicochemical Composition and Fatty Acid Profile of Goat Kids' Meat Fed Ground-Corn-Grain Silage Rehydrated with Different Additives

The effects of the replacement of dry ground corn (GC) with corn-grain silage rehydrated with water (RCSwater), cactus pear mucilage (RCSmucilage), and whey (RCSwhey) on the growth, physicochemical composition, and fatty acid profile of goat kids’ meat were investigated. Thirty-two crossbred goat kids (16.4 ± 2.50 kg initial weight) were assigned in a randomized block design with four treatments and eight repetitions. The NDF intake of goat kids fed with RCSmucilage was higher in comparison to RCSwater and RCSwhey (p = 0.0009). The dietary replacement of GC by RCSmucilage increased the final weight (p = 0.033) and meat-cooking losses (p = 0.0001) of kids. The concentrations of oleic (p = 0.046), 11,14-eicosadienoic (p = 0.033), and EPA (p = 0.010) were higher in the meat of kids fed with RCSmucilage and RCSwhey, and the α-linolenic concentration was higher (p = 0.019) for animals feeding with RCSmucilage. Meat from kids fed with RCSwhey presented the lowest ∑SFA and the highest ∑MUFA. In contrast, the ∑PUFA (p < 0.012) was higher for goats fed with RCSwater. The ∑ω3 (p < 0.0001) was higher in animals fed with RCSmucilage and RCSwhey. Desirable fatty acids were higher (p = 0.044) in animals fed with RCSmucilage and RCSwhey, and the atherogenicity (p = 0.044) and thrombogenicity (p < 0.0001) indexes were lower for goats fed the RCSwhey diet. The enzymatic activities of Δ9desaturase (C16) were higher (p = 0.027) in goat kids fed with GC and RCSmucilage, and Δ9desaturase (C18) was higher (p = 0.0497) when goats were fed with RCSmucilage and RCSwhey. Elongase activities were higher (p = 0.045) in goat kids fed with GC and RCSwater. The total replacement of GC by RCSmucilage is recommended in the diet of goat kids due to improvements in the weight gain and proportion of desirable fatty acids in the meat. In addition, RCSmucilage promoted better conservation of the silage at a lower cost when compared to commercial additives.

Microbiome-driven breeding strategy potentially improves beef fatty acid profile benefiting human health and reduces methane emissions

BACKGROUND

Healthier ruminant products can be achieved by adequate manipulation of the rumen microbiota to increase the flux of beneficial fatty acids reaching host tissues. Genomic selection to modify the microbiome function provides a permanent and accumulative solution, which may have also favourable consequences in other traits of interest (e.g. methane emissions). Possibly due to a lack of data, this strategy has never been explored.

RESULTS

This study provides a comprehensive identification of ruminal microbial mechanisms under host genomic influence that directly or indirectly affect the content of unsaturated fatty acids in beef associated with human dietary health benefits C18:3n-3, C20:5n-3, C22:5n-3, C22:6n-3 or cis-9, trans-11 C18:2 and trans-11 C18:1 in relation to hypercholesterolemic saturated fatty acids C12:0, C14:0 and C16:0, referred to as N3 and CLA indices. We first identified that ~27.6% (1002/3633) of the functional core additive log-ratio transformed microbial gene abundances (alr-MG) in the rumen were at least moderately host-genomically influenced (HGFC). Of these, 372 alr-MG were host-genomically correlated with the N3 index (n=290), CLA index (n=66) or with both (n=16), indicating that the HGFC influence on beef fatty acid composition is much more complex than the direct regulation of microbial lipolysis and biohydrogenation of dietary lipids and that N3 index variation is more strongly subjected to variations in the HGFC than CLA. Of these 372 alr-MG, 110 were correlated with the N3 and/or CLA index in the same direction, suggesting the opportunity for enhancement of both indices simultaneously through a microbiome-driven breeding strategy. These microbial genes were involved in microbial protein synthesis (aroF and serA), carbohydrate metabolism and transport (galT, msmX), lipopolysaccharide biosynthesis (kdsA, lpxD, lpxB), or flagellar synthesis (flgB, fliN) in certain genera within the Proteobacteria phyla (e.g. Serratia, Aeromonas). A microbiome-driven breeding strategy based on these microbial mechanisms as sole information criteria resulted in a positive selection response for both indices (1.36±0.24 and 0.79±0.21 sd of N3 and CLA indices, at 2.06 selection intensity). When evaluating the impact of our microbiome-driven breeding strategy to increase N3 and CLA indices on the environmental trait methane emissions (g/kg of dry matter intake), we obtained a correlated mitigation response of -0.41±0.12 sd.

CONCLUSION

This research provides insight on the possibility of using the ruminal functional microbiome as information for host genomic selection, which could simultaneously improve several microbiome-driven traits of interest, in this study exemplified with meat quality traits and methane emissions. Video Abstract.

Condensed tannins to increase bioactive fatty acids in the milk from Canindé, Repartida, and Saanen goats

Bioactive fatty acids present in goat milk have the ability to reduce the risks of coronary heart disease in humans, and condensed tannins (CT) can modulate the polyunsaturated fatty acids (PUFA) biohydrogenation process in the rumen and consequently increase the levels of these fatty acids. Thus, the objective was to evaluate the inclusion of CT in the diet for Canindé, Repartida, and Saanen goats to increase the level of bioactive fatty acids in milk. Twenty-two lactating does of three genetic groups, six Canindé, eight Repartida, and eight Saanen, were randomly assigned in a 3 × 2 factorial arrangement of three genetic groups and two diets (control and with 50 g CT/kg DM). The inclusion of CT in the diet did not change (P > 0.05) nutrient intake and performance. However, the inclusion of CT promoted an increase (P < 0.05) in C14:1; cis-9; C18:2n6; C18:3n6; C18:3n3; PUFA; and long-chain fatty acids and reduction (P < 0.05) of C11; C12; C14; ω6/ω3; and atherogenicity index in milk fat. Thus, it is recommended to include CT in the diet for Canindé, Repartida, and Saanen goats to increase the level of bioactive fatty acids in milk. The inclusion of the tannins of Acacia mearnsii promoted an increase in C14:1; cis-9; C18:2n6; C18:3n6; C18:3n3; polyunsaturated fatty acid; and long-chain fatty acids and reduction of C11; C12; C14; ω6/ω3; and atherogenicity index in milk fat.

Effect of dietary buriti oil on the quality, fatty acid profile and sensorial attributes of lamb meat

Forty crossbred (Santa Ines × Dorper) male lambs were used to investigate the effect of dietary buriti oil (BOIL) intake on meat quality, fatty acid (FA) composition and sensory attributes. A completely randomized design with five BOIL intake levels (0, 12, 24, 36 and 48 g/kg DM) was used. Increasing dietary BOIL intake linearly reduced the DMI, slaughter weight, cooking loss, shear force, yellowness, 16:0, c9-18:1 FA concentrations, and the delta-9-desaturase activity index computed using c9-16:1 and 16:0 as product and substrate pair, cis-MUFA and ƩMUFA/ƩSFA ratio of lamb meat (P ≤ 0.05); however, increasing dietary BOIL intake quadratically increased the energy intake, lipid content and linearly increased the total FA intake, chroma, collagen, total BI, 18:0, 20:3n-6 concentration and sensory attributes of lamb meat (P ≤ 0.05), without affecting health indexes regarding fat consumption. BOIL addition at levels above 24 g/kg DM in lamb diet reduces growth, however, improves tenderness, flavor and "goat" aroma intensity and slightly changes meat FA levels, promoting better acceptance by panelists.

Palm kernel cake in high-concentrate diets improves animal performance without affecting the meat quality of goat kids

Context Goat farming is an important socio-economic activity. The feedlot system allows the finishing of the animals in short periods through use of concentrated diets; however, these diets increase the system’s production costs. Palm kernel cake (PKC) has proved to be a good alternative feed source in diets for cattle and sheep because of its nutritional characteristics and potential to reduce production costs. Aim This experiment aimed to evaluate the effect of high-concentrate diets with the inclusion of PKC on carcass traits and meat quality of feedlot goat kids. Methods Thirty-two crossbred, castrated Boer goat kids, 4 months old and of average initial body weight 19.65±3.00kg, were used in the study. The animals were assigned to treatments in a completely randomised design, with four experimental diets containing PKC at 0%, 12%, 24%, and 36% on a dry matter basis. Measurements included total weight gain at slaughter, quantitative and sensory meat characteristics, and fatty acid profile. Key results A quadratic effect (P&lt;0.05) on total weight gain, and on meat marbling, lightness, and yellowness, was observed. The highest total weight gain and marbling were recorded with the diet containing 12% PKC. Loin eye area was also highest at 12% PKC, then decreased, whereas protein content and shear force increased (P&lt;0.05) at the higher PKC levels. Diet affected (P&lt;0.05) saturated, monounsaturated, and polyunsaturated fatty acids. No effect was observed from the inclusion of PKC on sensory attributes or on nutritional quality of the lipid fraction of the meat. Conclusion It is recommended the use up to 12% of this alternative source of nutrients, owing to the higher total weight gain and improved quantitative aspects of the goat kids’ meat such as marbling and loin eye area. Implications High-concentrate diets and the use of by-products for animal nutrition have become common in animal production systems. The increasing use of PKC in animal nutrition leads us to determine the best dietary inclusion level, avoiding undesirable production or product quality characteristics.

Fatty acid profile, oxidative stability of lipids and sensory attributes of water restricted Xhosa goat meat supplemented with vitamin C

Context Water scarcity often accompanied by limited water intake (WI) in livestock may result in pre-slaughter stress, thereby affecting meat quality parameters. Aims This study was conducted to determine the effect of vitamin C (VC) supplementations on fatty acid (FA), lipids oxidation and sensory attributes of Longissimus lumborum muscles of Xhosa goats subjected to different watering regimen. Methods In total, 42 goats were randomly assigned into seven treatments: without water restriction, WR (W0, control); WR of 70% of ad libitum WI (W70); WR of 50% ad libitum WI (W50); WR of 70% of ad libitum WI+3gVC daily (W70+); WR of 50% of ad libitum WI intake+3gVC daily (W50+); WR of 70% of ad libitum WI+3gVC and extra 5gVC given every 8 days (W70++); WR of 50% of ad libitum WI+3gVC and extra 5gVC given every 8 days (W50++). The goats were fed for 75 days and killed following standard procedures. Bodyweight changes, thaw loss, ultimate pH (pHu), thiobarbituric acid reactive substance (TBARS), moisture and fat content, sensory attributes and FA profile of the meat were evaluated. Key results Results indicated that the decreased final weight in the untreated groups (W70 and W50) was reduced (P&gt;0.05) in the treated groups (W70+, W50+, W70++, W50++). The treatment effect was not significant (P&gt;0.05) on pHu, thaw loss and TBARS values. The moisture and fat content in the water-restricted groups were lower (P&lt;0.05) than in W0. The meat sensory appearance was affected (P&lt;0.05) by WR. Regardless of VC concentration, vaccenic and docosahexaenoic acid increased (P&lt;0.05), while linolenic acid decreased as the WR levels increased. Conclusions WR of 70% and 50% of ad libitum WI, with or without VC, did not negatively affect the meat’s lipid oxidation and FA profile. Implications Limited WI reduces body weight. However, a daily dose of VC could help reduce body weight loss during water scarcity.

Protected or Unprotected Fat Addition for Feedlot Lambs: Feeding Behavior, Carcass Traits, and Meat Quality

Simple Summary

The use of lipids in ruminant diets aims to increase energy density without affecting the animal’s performance; however, its use can be toxic to the ruminal microbiota, which can be avoided with the use of protected fats. Diets with the inclusion of different fat sources (whole soybean grain, corn germ, calcium salt of fatty acids, and soybean oil) were tested to evaluate the effects of unprotected or protected fats on feeding behavior, carcass characteristics, and quality of the meat of feedlot lambs. The use of calcium salts from fatty acids in feedlot lambs’ diets improves the quantitative and qualitative characteristics of the carcass and meat.

Abstract

This study aimed to evaluate the effect of the inclusion of protected or unprotected fats in the diet of feedlot lambs on feeding behavior, productive characteristics, carcass traits, and meat quality. Forty male Dorper × Santa Inês lambs (22.27 ± 2.79 kg) were randomly assigned to treatments in a completely randomized design. The experimental treatments consisted of five diets: no added fat (NAF), whole soybeans (WSB), calcium salts of fatty acids (CSFA), soybean oil (SO), and corn germ (CG). The total intake of dry matter (DMI) (p < 0.001) and neutral detergent fiber (NDFI) (p = 0.010) were higher in the CSFA and NAF diets. Feeding behavior, morphometric measurements, physicochemical characteristics, and centesimal composition of the Longissimus lumborum muscle were similar between treatments (p > 0.05). The CSFA diet provided higher production (p < 0.05) and better-quality carcasses. The inclusion of fat sources increased the concentration of polyunsaturated fatty acids (p < 0.05). The use of calcium salts of fatty acids in feedlot lambs’ diets provides better quantitative and qualitative characteristics of the meat and carcass.

Chitosan and cottonseed processing method association on carcass traits and meat quality of feedlot lambs

The objective of this study was to evaluate the effects of the association of cottonseed processing method with chitosan on carcass traits and meat quality of lambs finished in feedlot. Eighty lambs with an average body weight of 20.6 kg, with 04 months of age, were distributed in a completely randomized design, in a 2 x 2 factorial arrangement. The factors were represented by two cottonseed processing method (whole or ground) and two levels of chitosan (0 and 136 mg/kg BW). The association of cottonseed processing method with chitosan in the lamb diet did not affect (P>0.05) carcasses traits. The pH, color, cooking losses, shear force, and proximate composition of meat were also not affected (P>0.05) by the processing method of cottonseed or its association with chitosan in the lamb diets. There was an increase in palmitoleic (c9-C16:1; P = 0.01) and conjugated linoleic (P = 0.02) fatty acids when ground cottonseed was associated with chitosan. Ground cottonseed associated with chitosan increases the concentration of unsaturated fatty acids in the meat of feedlot lambs.

Low carbohydrate diet: are concerns with saturated fat, lipids, and cardiovascular disease risk justified?

PURPOSE OF REVIEW

There is an extensive literature on the efficacy of the low carbohydrate diet (LCD) for weight loss, and in the improvement of markers of the insulin-resistant phenotype, including a reduction in inflammation, atherogenic dyslipidemia, hypertension, and hyperglycemia. However, critics have expressed concerns that the LCD promotes unrestricted consumption of saturated fat, which may increase low-density lipoprotein (LDL-C) levels. In theory, the diet-induced increase in LDL-C increases the risk of cardiovascular disease (CVD). The present review provides an assessment of concerns with the LCD, which have focused almost entirely on LDL-C, a poor marker of CVD risk. We discuss how critics of the LCD have ignored the literature demonstrating that the LCD improves the most reliable CVD risk factors.

RECENT FINDINGS

Multiple longitudinal clinical trials in recent years have extended the duration of observations on the safety and effectiveness of the LCD to 2-3 years, and in one study on epileptics, for 10 years.

SUMMARY

The present review integrates a historical perspective on the LCD with a critical assessment of the persistent concerns that consumption of saturated fat, in the context of an LCD, will increase risk for CVD.

In vitro rumen biohydrogenation of unsaturated fatty acids in tropical grass-legume rations

Aim:

The aim of this study was to evaluate the effects of various combinations of tropical grass-legume species in rations on the biohydrogenation (BH) activity of unsaturated fatty acids (FAs), C18:0 composition, and fermentation profile in an in vitro rumen system.

Materials and Methods:

Samples of the following five fodder plants were used: One species of grass (Pennisetum purpureum) and four species of tree legumes (Leucaena leucocephala, Gliricidia sepium, Calliandra calothyrsus, and Indigofera zollingeriana). The following eight experimental diets were evaluated: 50% P. purpureum + 50% L. leucocephala (LL I); 50% P. purpureum + 50% G. sepium (GS I); 50% P. purpureum + 50% C. calothyrsus (CC I); 50% P. purpureum + 50% I. zollingeriana (IZ I); 75% P. purpureum + 25% L. leucocephala (LL II); 75% P. purpureum + 25% G. sepium (GS II); 75% P. purpureum + 25% C. calothyrsus (CC II); and 75% P. purpureum + 25% I. zollingeriana (IZ II). Each ration was replicated 3 times. In vitro rumen incubation was performed for 48 h, according to the Tilley and Terry method. Determination of the FA profiles of the forage materials and rumen fluid samples was performed using gas chromatography.

Results:

The percentage of polyunsaturated FA (PUFA) in the forage materials ranged from 34.18% (P. purpureum) to 74.51% (C. calothyrsus). The percentage of monounsaturated FA (MUFA) ranged from 5.06% (P. purpureum) to 8.71% (L. leucocephala). The percentage of saturated FA (SFA) was the lowest at 19.12% (C. calothyrsus) and highest at 60.76% (P. purpureum). In vitro BH of C18:3 n-3, C18:2 n-6, C18:1 n-9, and C18 PUFA in the experimental diets ranged from 72% to 100%. The BH of C18:1 n-9 in GS I (80%) and IZ I (72%) was significantly different (p<0.05). The percentage of C18:0 was 10-50% and significantly different (p<0.05) among treatments, with the highest (of 50%) in GS II. No significant differences (p>0.05) were observed in the fermentation parameters (pH, total volatile FAs, in vitro dry matter digestibility, and in vitro organic matter digestibility) among the treatments, except in NH₃ concentration (p<0.05).

Conclusion:

The various combinations of tropical legumes do not have significant inhibitory effects on the BH of C18:2 n-6, C18:3 n-3, and C18 PUFA after in vitro incubation for 48h. Furthermore, an increase in the tropical legume ratio in the ration tends to suppress C18:0 formation after the fermentation simulation process. IZ I has the potential to reduce C18:1 n-9 (MUFA) disappearance and yield an ideal rumen fermentation profile.

Advances in our understanding of the structure and functionality of edible fats and fat mimetics

The reasons for the increased world-wide incidence of obesity, type-2 diabetes, and cardiovascular disease include sedentary lifestyles and poor food choices. Regulatory agencies in several countries now require companies to add unattractive front of package labels to their products where salt, sugar and fat (or saturated fat) levels are prominently displayed. After the demise of partially hydrogenated fats, saturated fat has become the new target. Consumption of saturated fat over polyunsaturated oil has been clearly shown to increase cholesterol levels in humans. However, saturated fats provide the functionality required in many food products. To complicate matters, concerns over sustainability, veganism, genetically modified organisms, animal welfare, as well as religious beliefs, severely limit our sources of saturated fat. In this review we will discuss recent advances in our understanding of the nano and mesoscale structure of fats, responsible for their physical functionality and contrast it to that of fat mimetics. Fat mimetics include polymeric networks of ethylcellulose, emulsion-templated networks of proteins and polysaccharides, colloidal and self-assembled fibrillar networks of polar lipid crystals, as well as solid o/w emulsions of oil trapped within crystallized lamellar mesophases. Clean label and economic considerations will also be touched upon.

Fatty acid, chemical, and tissue composition of meat comparing Santa Inês breed sheep and Boer crossbreed goats submitted to different supplementation strategies

To compare the fatty acid (FA) composition, and chemical and tissue composition of meat, 24 uncastrated males, 12 sheep of the Santa Inês breed, and 12 crossbred goats (F1 Boer × undefined breed) with the weight of 24.3 ± 2.38 kg. The animals were distributed in a randomized block design and treatments were arranged in a 2 × 2 factorial design, two small ruminant species/breed (Boer crossbreed goat × Santa Inês breed sheep), and two supplementation strategies (energy × protein energy). There was not an interaction between the small ruminant species and the supplementation on average daily gain, tissue composition, chemical composition, or FA profile of the longissimus lumborum muscle. Sheep presented greater weight and yield of fat in the subcutaneous, intermuscular, and total depots than goats, which results in better finishing of the sheep for slaughter. Goat meat presented a lower lipid concentration than sheep meat. The protein-energy supplementation increased oleic acid, ΣUFA, ΣMUFA, hypocholesterolemic/ Hypercholesterolemic index, and enzymatic activity Δ9-desaturase C18 and decreased SFA capric acid in the muscle when compared with energetic supplementation. In Caatinga biome conditions, Boer crossbreed goats meat has a lower concentration of lipids and a healthier FA composition compared with Santa Inês breed sheep because it has a lower SFA and greater PUFA content, which are sources of n-3 and n-6, which may contribute to the reduction of blood cholesterol (LDL). In addition, protein-energy supplementation also improved the quality of animal fat compared with supplementation only with the energetic concentrate, regardless of species.

Effect of Feeding Cows with Unsaturated Fatty Acid Sources on Milk Production, Milk Composition, Milk Fatty Acid Profile, and Physicochemical and Sensory Characteristics of Ice Cream

Simple Summary

The objective of this study was to evaluate the effects of supplementation of dairy cows’ diets with different fatty acid (FA) sources on milk production, milk composition, milk fatty acid profile, and physicochemical and sensory characteristics of ice cream. Supplementation (3% dry matter (DM)) of diets with soybean oil (SO) and fish oil (FO) did not have detrimental effects on milk production, milk composition, or ice cream physicochemical and sensory characteristics. From a human standpoint, SO and FO improved the FA profile of milk.

Abstract

The objective of this study was to evaluate the effects of supplementation of dairy cows with different fatty acid sources (soybean oil (SO) and fish oil (FO)) on milk production, milk composition, milk fatty acid profile, and physicochemical and sensory characteristics of ice cream. During 63 days, fifteen Holstein cows averaging 198 ± 35 days in milk were assigned to three groups: control diet with no added lipid (n = 5 cows); and supplemented diets with SO (n = 5 cows; unrefined SO; 30 g/kg DM) or FO (n = 5 cows; FO from unrefined salmon oil; 30 g/kg DM). Milk production, milk fat, and milk protein were not affected by treatments. Saturated fatty acids in milk fat were decreased with SO and FO compared with control. C18:2 cis-9, cis-12 was increased with SO whereas C18:2 cis-9, trans-11, C20:3n-3, C20:3n-6, C20:5n-3, and C22:6n-3 were the highest with FO. Draw temperature and firmness were higher in SO compared to control and FO ice creams. Melting resistance was higher in FO compared with control and SO ice creams. Supplementation of cow diets with SO and FO did not have detrimental effects on milk production, or ice cream physicochemical and sensory characteristics.

Reprint of "Postprandial lipemia and fecal fat excretion in rats is affected by the calcium content and type of milk fat present in Cheddar-type cheeses"

The aim of this study was to better understand the effect of calcium on the bioavailability of milk lipids from a cheese matrix using a rat model. Cheddar-type cheeses were manufactured with one of three types of anhydrous milk fat, control, olein or stearin, and salted with or without CaCl₂. The cheeses were fed to rats and postprandial lipemia was monitored. Feces were analyzed to quantify fatty acids excreted as calcium soaps. Higher calcium concentration in cheese caused a higher and faster triacylglycerol peak in blood, except for cheeses containing stearin. Furthermore, calcium soaps were more abundant in feces when the ingested cheese had been enriched with calcium and when the cheese was prepared with stearin. Increased lipid excretion was attributable to the affinity of saturated long-chain fatty acids for calcium. Results showed that lipid bioaccessibility can be regulated by calcium present in Cheddar cheese. This study highlights the nutritional interaction between calcium and lipids present in the dairy matrix and confirms its physiological repercussions on fatty acid bioavailability.

Physicochemical characteristics and fatty acid composition of the meat of lambs fed cassava silage and dry tamarind (Tamarindus indica)

The objective of the present study was to determine the effect of the addition of dry tamarind (Tamarindus indica L.) residue to cassava (Manihot esculenta, Crantz) silage on the carcass traits, quality and fatty acid profile of lamb meat. Forty 6-month-old (±2 days) castrated lambs (crossbred Santa Ines × mixed breed) with initial bodyweights of 22.1 ± 3.0 kg were used in a completely randomised design with four treatments (0, 100, 200 or 300 g/kg of DM of dry tamarind residue) and 10 replicates (animals). There was a significant increase in hot carcass weight (P &lt; 0.001) and loin weight (P = 0.04); however, there were no effects on final bodyweight, average daily weight gain, slaughter weight, weights of other commercial cuts, shear force, lightness (L*), redness (a*), yellowness (b*), chroma (C*), lipid profile, ash content, initial and final pH value and cooking weight loss. There was a significant (P &lt; 0.001) quadratic reduction in water-holding capacity with an increasing tamarind residue content. The addition of tamarind residue to cassava silage linearly decreased the lauric (C12:0; P = 0.01) and stearic (C18:0; P = 0.01) fatty acid concentrations (total saturated fatty acids, ΣSFA) (P = 0.03) and the ratio of ΣSFA to unsaturated fatty acids (ΣSFA:ΣUFA; P = 0.04). However, there were linear increases in the C18:2 cis9, cis12 concentration (P = 0.04), polyunsaturated fatty acid n-6 concentration (P = 0.05), ΣUFA (P = 0.03) and the Σn-6:Σn-3 ratio (P = 0.01) in the lamb meat. Dry tamarind can be added to cassava up to a level of 300 g/kg of DM without any negative effects on the performance or meat quality, and it increases the yield of the loin cut, polyunsaturated fatty acid n–6 and ΣUFA, which makes the lamb meat healthier.

Fatty acid, physicochemical composition and sensory attributes of meat from lambs fed diets containing licuri cake

The aim of this study was to determine the effect of feeding licuri cake to lambs on the sensory characteristics, physicochemical characteristics and fatty acid (FA) profile of meat from lambs. Forty-four crossbred Santa Ines lambs (21.2 ± 2.70 kg body weight; 6 months old) were housed in individual pens and fed 4 experimental diets, containing 0, 8, 16 or 24% licuri cake (DM basis). The averages concentrations of ash (11.4), pH (5.82), lightness (38.1), cooking loss (26.8) or shear-force resistance (2.48) of lamb meat were not affected by the licuri cake diets. However, there was a linear decrease (P < 0.01) of redness and chroma indexes, lipid and protein contents, whereas the moisture content of the meat (P < 0.001) increased linearly due to the inclusion of licuri cake in lambs’ diets. The licuri cake inclusion in the lambs feed linearly increased (P < 0.05) the fatty acids concentrations of C12:0, C17:0, C20:0, C20:1, C18:3, C20:3, C20:4 and ΣPUFA/ΣMUFA ratio, Σω–3 and atherogenicity index (AI). However, C18:1 cis, C20:2, C20:5, ΣMUFA, ΣMUFA/ΣSFA and Σω–6:Σω–3 ratios in the longissimus lumborum of lambs linearly decreased by licuri cake inclusion. There was a quadratic increase (P < 0.05) on C14:0 (maximum point 4.94 g/100 g FAME to 14.5% licuri inclusion), C16:1 (maximum point 8.59 g/100 g FAME to 10.7% licuri inclusion) and enzymatic activities of Δ⁹-desaturase C16 (maximum point 27.5 g/100 g FAME to 10.6% licuri inclusion) in the longissimus lumborum of lambs fed due to increased concentrations of licuri cake. However, there was a quadratic decrease (P = 0.04) in ΣPUFA/ΣSFA ratio with minimum concentration of 0.63 g/100 g FAME to 11.1% inclusion. The inclusion of licuri cake in the lambs diet did not change (P > 0.05) the concentrations of SFA C10:0, C15:0, C16:0, C18:0, C14:1, MUFA C18:1 trans, PUFA C18:2 cis, CLA, total sum of ΣSFA and ΣPUFA, desirable fatty acids (DFA), hypocholesterolemic:hypercholesterolemic index, and elongase and Δ⁹-desaturase C18 enzymes. Licuri cake in the lamb diet improved (P < 0.05) meat aroma, flavor and overall acceptance by consumers. Licuri cake inclusion in the diet of lambs improves sensory attributes of meat and the meat fatty acid profile becomes nutritionally healthier for the human diet because do not affect major FA of meat; however, the growth performance of finishing lambs is reduced.

Review: Modulating ruminal lipid metabolism to improve the fatty acid composition of meat and milk. Challenges and opportunities

Growth in demand for foods with potentially beneficial effects on consumer health has motivated increased interest in developing strategies for improving the nutritional quality of ruminant-derived products. Manipulation of the rumen environment offers the opportunity to modify the lipid composition of milk and meat by changing the availability of fatty acids (FA) for mammary and intramuscular lipid uptake. Dietary supplementation with marine lipids, plant secondary compounds and direct-fed microbials has shown promising results. In this review, we have compiled information about their effects on the concentration of putative desirable FA (e.g. c9t11-CLA and vaccenic, oleic, linoleic and linolenic acids) in ruminal digesta, milk and intramuscular fat. Marine lipids rich in very long-chain n-3 polyunsaturated fatty acids (PUFA) efficiently inhibit the last step of C18 FA biohydrogenation (BH) in the bovine, ovine and caprine, increasing the outflow of t11-18:1 from the rumen and improving the concentration of c9t11-CLA in the final products, but increments in t10-18:1 are also often found due to shifts toward alternative BH pathways. Direct-fed microbials appear to favourably modify rumen lipid metabolism but information is still very limited, whereas a wide variety of plant secondary compounds, including tannins, polyphenol oxidase, essential oils, oxygenated FA and saponins, has been examined with varying success. For example, the effectiveness of tannins and essential oils is as yet controversial, with some studies showing no effects and others a positive impact on inhibiting the first step of BH of PUFA or, less commonly, the final step. Further investigation is required to unravel the causes of inconsistent results, which may be due to the diversity in active components, ruminant species, dosage, basal diet composition and time on treatments. Likewise, research must continue to address ways to mitigate negative side-effects of some supplements on animal performance (particularly, milk fat depression) and product quality (e.g. altered oxidative stability and shelf-life).

Analysis of fatty acid profiles of free fatty acids generated in deep-frying process

During the deep fat food frying process, the frying media, oil, continuously degenerates when exposed to high temperature, oxygen and moisture. This leads to physical and chemical changes including the formation of hydrolysis products such as free fatty acids (FFAs) which are associated with undesirable darkening in colour, off-flavouring and a lowering of the smoke point. This study was aiming to develop a method capable of identifying and quantifying individual free fatty acids within oil using a small sample size (100 mg of oil). We used liquid/liquid extraction technique to separate FFAs from the rest of the oil followed by esterification using boron trifluoride (BF3) and then gas chromatography analysis. Various extraction conditions were tested. A mixture of 0.02 M phosphate buffer at pH 12 and acetonitrile at solvent: buffer ratio larger than 2:1 showed the highest efficiency in extraction of FFAs. The method was capable of producing accurate fatty acid profiles of FFAs and showed good precision on medium rancidity oil samples. It also captured the differences induced by adding free fatty acids to samples. An interesting discrepancy was found between the new method and the traditional titration method in terms of overall FFA content, which suggests further optimisation and investigation are required.

Physicochemical Quality, Fatty Acid Composition, and Sensory Analysis of Nellore Steers Meat Fed with Inclusion of Condensed Tannin in the Diet

This study was conducted to test the effect of dietary tannin on the fatty acid profile and sensory attributes of meat from Nellore steers. Thirty-two Nellore bull male were distributed in a completely randomized design and fed diets with condensed tannin extract as follows: 0, 10, 30, and 50 g/kg total DM basis. The physicochemical composition of the meat, lipid oxidation, fatty acid profile, flavor, tenderness, and overall acceptance were evaluated. There was a linear decrease (P ≤ 0.05) on lipid content, tenderness, cooking weight loss, myristic, palmitic, and oleic acids in meat as tannin increased in the diets. The total saturated and monounsaturated fatty acids, the atherogenicity index decreased. However, a linear increase (P ≤ 0.05) was observed for linoleic, linolenic, arachidonic, eicosapentaenoic, and docosapentaenoic acids. The physicochemical characteristic of the meat, such as moisture, ash, and protein contents, water retention capacity, final pH, Warner-Bratzler shear force, collagen, and color indexes (lightness, redness, yellowness, and chrome) did not change with dietary tannin. Also, CLA, n-6:n-3 ratio, Δ⁹ -desaturase, and elongase activity were not different among diets. In conclusion, condensed tannin linearly increases unsaturated fatty acids and decreases the atherogenicity index of meat; thus, it can be recommended at the highest level (50 g/kg DM) in the diet of Nellore steers.

PRACTICAL APPLICATION

Agriculture byproducts plays an important part in the diet of ruminant animals and consequently on food chain and has implications for the composition and quality of the livestock products (milk, meat, and eggs) that people consume. Feeding tannin to steers increases the amount of unsaturated fatty acids and meat tenderness, with a concomitant reduction on saturated fatty acids and the atherogenicity index in meat. Thus, we recommend adding tannin to steer diets to reduce the risk factors for cardiovascular diseases in red meat for human consumption.

Postprandial lipemia and fecal fat excretion in rats is affected by the calcium content and type of milk fat present in Cheddar-type cheeses

The aim of this study was to better understand the effect of calcium on the bioavailability of milk lipids from a cheese matrix using a rat model. Cheddar-type cheeses were manufactured with one of three types of anhydrous milk fat, control, olein or stearin, and salted with or without CaCl₂. The cheeses were fed to rats and postprandial lipemia was monitored. Feces were analyzed to quantify fatty acids excreted as calcium soaps. Higher calcium concentration in cheese caused a higher and faster triacylglycerol peak in blood, except for cheeses containing stearin. Furthermore, calcium soaps were more abundant in feces when the ingested cheese had been enriched with calcium and when the cheese was prepared with stearin. Increased lipid excretion was attributable to the affinity of saturated long-chain fatty acids for calcium. Results showed that lipid bioaccessibility can be regulated by calcium present in Cheddar cheese. This study highlights the nutritional interaction between calcium and lipids present in the dairy matrix and confirms its physiological repercussions on fatty acid bioavailability.

Feeding sunflower cake from biodiesel production to Santa Ines lambs: Physicochemical composition, fatty acid profile and sensory attributes of meat

The aim of this study was to determine the effect of the inclusion of sunflower cake in the diets of lambs on meat quality. Forty male, uncastrated Santa Ines lambs with an initial average body weight of 20.9 ± 0.41 kg were used in a completely randomized design with four treatments. The lambs were fed 500 g/kg hay and 500 g/kg concentrate (corn, soybean meal, urea, ammonium sulfate and sunflower cake) in their diet, and the experimental treatments were 0, 10, 20, and 30% sunflower cake inclusion (DM basis). The inclusion of sunflower cake in the diet did not affect (P > 0.05) the content of ash and protein, overall acceptance, or sensory aroma of the lamb meat. Total lipids and moisture content of the longissimus lumborum muscle increased linearly (P ≤ 0.05) with sunflower cake inclusion. The C16:0, ΣSFA, ΣMUFA:ΣSFA ratio, Δ–9 desaturase enzyme and atherogenicity index in the longissimus lumborum muscle decreased linearly (P ≤ 0.05) with sunflower cake inclusion in lamb diets, whereas a linear increase occurred (P ≤ 0.05) in C12:0, C18:0, ΣMUFA, ΣPUFA, ΣPUFA:ΣSFA and ΣPUFA:ΣMUFA ratios, Σn–6, Σn–3, desirable fatty acids, h:H index, elongase activity, and flavor, tenderness and juiciness sensory qualities in lamb meat. Among the panelists, the highest preference (35.9%) was for meat with 30% sunflower cake inclusion in the diet. Sunflower cake up to 30% of total DM can be included in the diet of Santa Ines lambs, because lipid nutritional quality and the sensory qualities of the lamb meat increase, in addition to improvement in nutraceutical compounds, such as the CLA content, and in the AI, PUFA:SFA and PUFA:MUFA ratios, desirable fatty acids content and h:H ratio, which are beneficial to the health of consumers.

Nutritional Evaluation of an EPA-DHA Oil from Transgenic Camelina sativa in Feeds for Post-Smolt Atlantic Salmon (Salmo salar L.)

Vegetable oils (VO) are possible substitutes for fish oil in aquafeeds but their use is limited by their lack of omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA). However, oilseed crops can be modified to produce n-3 LC-PUFA such as eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, representing a potential option to fill the gap between supply and demand of these important nutrients. Camelina sativa was metabolically engineered to produce a seed oil with around 15% total n-3 LC-PUFA to potentially substitute for fish oil in salmon feeds. Post-smolt Atlantic salmon (Salmo salar) were fed for 11-weeks with one of three experimental diets containing either fish oil (FO), wild-type Camelina oil (WCO) or transgenic Camelina oil (DCO) as added lipid source to evaluate fish performance, nutrient digestibility, tissue n-3 LC-PUFA, and metabolic impact determined by liver transcriptome analysis. The DCO diet did not affect any of the performance or health parameters studied and enhanced apparent digestibility of EPA and DHA compared to the WCO diet. The level of total n-3 LC-PUFA was higher in all the tissues of DCO-fed fish than in WCO-fed fish with levels in liver similar to those in fish fed FO. Endogenous LC-PUFA biosynthetic activity was observed in fish fed both the Camelina oil diets as indicated by the liver transcriptome and levels of intermediate metabolites such as docosapentaenoic acid, with data suggesting that the dietary combination of EPA and DHA inhibited desaturation and elongation activities. Expression of genes involved in phospholipid and triacylglycerol metabolism followed a similar pattern in fish fed DCO and WCO despite the difference in n-3 LC-PUFA contents.

Fatty acid profiles of milk and Minas frescal cheese from lactating grazed cows supplemented with peanut cake

Milk and Minas frescal cheese were evaluated from crossbred Holstein × Gir cows that were fed diets enriched with 0, 33, 66 and 100% inclusion levels of palm kernel cake in a concentrated supplement in replace of soybean meal. Eight crossbred lactating cows were distributed (four animals × four treatments × four periods) in the experimental design of double 4 × 4 Latin squares. The capric (C : 10, P = 0·0270), undecylic (C : 11, P = 0·0134), and lauric (C : 12, P = 0·0342) saturated fatty acid concentrations and CLA (C18 : 2c9t11, P = 0·0164) of the milk fat decreased linearly with an increasing percentage of peanut cake in the diet. The increased peanut cake content (100%) in the diet was associated with a linear decrease in C : 10 (P = 0·0447), C : 12 (P = 0·0002), mirystic (C : 14, P < 0·0001) and palmitic (C : 16, P < 0·0001) saturated fatty acid concentrations and an increase in arachidic, lignoceric, palmitoleic and elaidic acid levels in the Minas frescal cheese fat made from the milk. Both the milk and the Minas frescal cheese showed a linear decrease in the concentration of monosaturated fatty acids (P < 0·0001), atherogenicity index, and thrombogenicity index (P < 0·05), while the hypocholesterolaemic: hypercholesterolaemic and omega 6: omega 3 (P > 0·05) ratios were not influenced by the different peanut cake levels. The inclusion of up to 100% peanut cake as a substitution for soybean meal in the concentrate of grazing lactating cows resulted in changes in the nutritional quality of their milk products, as indicated by the increase in polyunsaturated fatty acids and the decrease of saturated fatty acids (lauric, myristic, and palmitic).