Modifying milk and meat fat quality through feed changes

Multiple biological activities and biosynthesis mechanisms of specific conjugated linoleic acid isomers and analytical methods for prospective application

Conjugated linoleic acid (CLA) is a collective term for the octadecadienoic acid isomers containing conjugated double bonds. This article reviewed CLA isomers from biological activities, biosynthesis mechanisms and analytical methods. The biological activities of CLA isomers in anti-obesity, cardiovascular protection, diabetes management and anti-cancer in vitro and in vivo were mainly reviewed. More attention has been paid to the production of the specific CLA isomer due to its biological activity. The biosynthesis methods of CLA isomers, such as dietary modification in ruminants and fermentation by microorganisms & enzymes, were systematically introduced. A rapid, accurate and economic analysis method will promote the research in both biological activities and biosynthesis mechanisms of CLA isomers. The merits of UV spectrometry, GC, HPLC, MS and CE used in the analysis of CLA isomers were also compared in detail. This paper aims to put into perspective the current status and future trends on CLA isomers.

Effects of Chia Seeds on Growth Performance, Carcass Traits and Fatty Acid Profile of Lamb Meat

The aim of this work was to supplement a diet with chia seeds (Salvia hispanica L.) based on the requirements of finishing lambs for meat, and to analyze biometric parameters and fatty acid profiles in meat. Eighteen male Rambouillet lambs with a bodyweight of 25 kg were used. Animals were kept in individual pens with water and feed provided ad libitum. Three finishing diets were designed with the inclusion of 0, 50 and 100 g dry matter chia seeds and divided among the animals (n = 6). The experimental period lasted 60 days. The weights of the individual lambs were recorded every 14 days. At the end of the experiment, the animals were slaughtered and the weights of the hot carcasses and non-meat components were registered. In addition, an analysis of the fatty acid composition was carried out in the muscles (Longissimus thoracis). The total weight gain and average daily gain displayed significant differences (p < 0.05). Initial and final bodyweights, such as the dry matter intake, did not display differences. The fatty acid profile of the meat tended to decrease the SFA (stearic acid) and increase MUFA (oleic acid) (p < 0.0001) when chia seeds were added to the lamb diets. In conclusion, chia seed supplementation did not increase meat production or other biometric parameters; however, it modified the fatty acid profile in L. thoracis.

Oilseed Supplementation Improves Milk Composition and Fatty Acid Profile of Cow Milk: A Meta-Analysis and Meta-Regression

Oilseed supplementation is a strategy to improve milk production and milk composition in dairy cows; however, the response to this approach is inconsistent. Thus, the aim of this study was to evaluate the effect of oilseed supplementation on milk production and milk composition in dairy cows via a meta-analysis and meta-regression. A comprehensive and structured search was performed using the following electronic databases: Google Scholar, Primo-UAEH and PubMed. The response variables were: milk yield (MY), atherogenic index (AI), Σ omega-3 PUFA, Σ omega-6 PUFA, fat, protein, lactose, linoleic acid (LA), linolenic acid (LNA), oleic acid (OA), vaccenic acid (VA), conjugated linoleic acid (CLA), unsaturated fatty acid (UFA) and saturated fatty acid (SFA) contents. The explanatory variables were breed, lactation stage (first, second, and third), oilseed type (linseed, soybean, rapeseed, cottonseed, and sunflower), way (whole, extruded, ground, and roasted), dietary inclusion level, difference of the LA, LNA, OA, forage and NDF of supplemented and control rations, washout period and experimental design. A meta-analysis was performed with the “meta” package of the statistical program R. A meta-regression analysis was applied to explore the sources of heretogeneity. The inclusion of oilseeds in dairy cow rations had a positive effect on CLA (+0.27 g 100 g−1 fatty acids (FA); p < 0.0001), VA (+1.03 g 100 g−1 FA; p < 0.0001), OA (+3.44 g 100 g−1 FA; p < 0.0001), LNA (+0.28 g 100 g−1 FA; p < 0.0001) and UFA (+8.32 g 100 g−1 FA; p < 0.0001), and negative effects on AI (−1.01; p < 0.0001), SFA (−6.51; p < 0.0001), fat milk (−0.11%; p < 0.001) and protein milk (−0.04%; p < 0.007). Fat content was affected by animal breed, lactation stage, type and processing of oilseed and dietary NDF and LA contents. CLA, LA, OA and UFA, desirable FA milk components, were affected by type, processing, and the intake of oilseed; additionally, the concentrations of CLA and VA are affected by washout and design. Oilseed supplementation in dairy cow rations has a positive effect on desirable milk components for human consumption. However, animal response to oilseed supplementation depends on explanatory variables related to experimental design, animal characteristics and the type of oilseed.

Using Fecal DNA Metabarcoding to Investigate Foraging Reveals the Effects of Specific Herbage on the Improved n-3 Fatty Acid (PUFA) Composition in the Longissimus Dorsi Muscle of Grazing Tan Sheep

Understanding the natural diet of grazing sheep can help fulfill their nutritional requirements and positively affect the quality of their meat. Emerging fecal DNA (fDNA) metabarcoding technology can provide more accurate estimates for the dietary composition of free-ranging animals. This study has shown that pasture feeding can promote deposition of n-3 polyunsaturated fatty acids (PUFAs) in Tan lambs' muscle and decrease the ratio of n-6/n-3 fatty acids (FAs), and thus, we investigated the dietary composition of grazing lambs using fDNA metabarcoding to assess the prevalence of medicinal herbage plants in their diet. Herein, based on the full-time natural pasture grazing and 4-h natural pasture grazing with indoor feeding patterns, the herbage taxa (Bassia scoparia, Euphorbia humifusa, Arnebia euchroma, and Salsola sp.) most correlated to n-3 PUFAs were highlighted to elucidate how diversification in dietary components was associated with the muscle FA profile of lambs. Our findings provide experimental evidence for future feeding research.

Grape Pomace Ingestion by Dry Cows Does Not Affect the Colostrum Nutrient and Fatty Acid Composition

Simple Summary

The introduction of alternative feedstuff such as grape pomace into the diets of dry cows could decrease the cereal needs in ruminant feeding systems and could modify the composition of colostrum. Grape pomace is a by-product of the wine industry. It contains polyphenols and fatty acids, which have the potential to improve the animal product quality. The nutritional quality of colostrum and the quality of colostral fat is affected by dry cow nutrition in the late stages of pregnancy. This study determined the potential of grape pomace feeding to increase colostral protein, which, according to the literature, is connected with the concentration of immunoglobulin G, better passive immunisation, and the health of calves. The addition of grape pomace was determined to have no effect on colostral nutrient and fatty acid concentrations. Thus, grape pomace can be used as a nutrient source for dry cows.

Abstract

The utilisation of different by-products from the food industry as nutrient sources for farm animals is both possible and beneficial. Grape pomace is a by-product that contains polyphenols and fatty acids, both of which have the potential to improve the nutritional quality of cow colostrum. This study aimed to explore how the addition of grape pomace to the diet of dry cows affects the concentration of nutrients and fatty acids of colostrum. Sixteen Slovak spotted cows in late pregnancy were used in this study. From the seventh day before expected calving to the day of calving, cows in the grape pomace group received a diet supplemented with dried grape pomace, at 0.116 kg/cow/day. Colostrum samples were analysed for basal nutrients and fatty acid concentrations. Between the control and experimental groups, the nutrient and fatty acid concentrations of all the colostrum samples did not show significant differences. The nutrient levels in the colostrum from both groups of cows were typical, as related to the time from calving. The addition of the grape pomace into the diet of dry cows had no effect on nutrient concentrations and the fatty acid composition of the colostrum. The somatic cell score of the colostrum sampled at the 12th hour after calving (4.2 versus 2.6) was positively affected by grape pomace addition. The results of this study revealed that grape pomace (fed in an amount of 0.116 kg/cow/day) had no positive or negative effect on the base nutrients and fatty acids of cow colostrum, and, therefore, grape pomace can be used as a nutrient source for dry cows in small amounts.

Feeding Broiler Chickens with Grape Seed and Skin Meals to Enhance α- and γ-Tocopherol Content and Meat Oxidative Stability

Grape seeds (GS) and grape skins (GK) are natural sources of polyphenols with featured antioxidant capacity. An experiment was conducted to investigate the effect of these polyphenol sources in diets formulated to contain the same total extractable grape polyphenol content on growth performance, protein and extractable polyphenol digestibility, plasma and meat α- and γ-tocopherol and thigh meat oxidation in broiler chickens. Five experimental diets were formulated: control, control + vitamin E (200 mg/kg), 30 g/kg GS diet, 110 g/kg GK diet, GS + GK diet (a mixture of 24.4 g/kg GS and 13.1 g/kg GK designed to simulate a reconstituted grape pomace). Feeding chickens with 110 g/kg GK reduced (p < 0.001) daily weight gain, worsened (p < 0.001) feed conversion ratio, increased (p < 0.001) non-extractable polyphenol content in the ileum and in the excreta and decreased (p < 0.05) ileal protein digestibility. Regardless of the grape polyphenol source used, the inclusion of grape byproducts in the diets led to an increase of total extractable polyphenol contents in the ileum (p < 0.01) and the excreta (p < 0.001), which resulted (p < 0.001) in a decrease of extractable polyphenol digestibilities. Alpha- and gamma-tocopherol concentrations increased (p < 0.001) in plasma and in seven-day stored meat in birds fed the diet combining GS and GK with respect to the control group. As it happened with the vitamin E supplementation, feeding the combination of GS and GK also reduced (p < 0.001) the concentration of the lipid peroxidation marker (malondialdehyde) in the stored meat of chickens.

Early consumption of ultra-processed foods among children under 2 years old in Brazil

Objective:

To evaluate the complementary food consumption according to the extent and purpose of food processing based on NOVA classification among children aged 6–24 months of Federal District, Brazil.

Design:

We performed a cross-sectional study using a 24-h recall to estimate the daily energy intake and nutrients according to NOVA classification. We conducted a linear regression to assess the association between the processed and ultra-processed foods (UPF) energy intake and the daily energy intake from saturated fat, daily energy intake from total sugars and daily intake of sodium.

Setting:

Federal District, Brazil.

Participants:

Five hundred and thirty-eight children aged between 6 and 24 months attended at Primary Health Care Units from March 2017 to March 2018.

Results:

On average, children aged from 6 to 12 and from 12 to 24 months consumed 2393 and 4054 kJ/d, respectively, and processed and UPF represented one-third of dietary energy intake. Group 2 (processed and UPF) was higher carbohydrate contributors, and lower protein, fibre and most micronutrient contributors, when compared with Group 1 (unprocessed, minimally processed foods and processed culinary ingredients). In addition, the higher the energy intake from processed and UPF, the higher was the daily energy intake from saturated fat, daily energy intake from total sugar and daily intake of sodium.

Conclusion:

Children are being exposed early to processed and UPF and their share affect the diet’s nutritional quality.

Physicochemical Characteristics, Fatty Acid Profile, Alpha-Tocopherol Content, and Lipid Oxidation of Meat from Ewes Fed Different Levels of Distilled Myrtle Residues

The aim of this work was to study the sheep meat physicochemical traits as affected by distilled myrtle residues (MR) supplementation. For this, 27 culled ewes were divided into three groups receiving a ration composed by concentrate and hay for the Control group, concentrate and MR as a total substitute to hay for the Myrt-H group, or hay, less concentrate, and MR as a partial substitute to concentrate for the Myrt-C group. The meat chemical composition, pH, and color parameters were not affected by the MR intake. However, this animal’s dietary treatment resulted in higher meat polyphenol and α-tocopherol content for both MR groups (9.38 and 8.05 vs. 3.04 μg g⁻¹ DM for Myrt-H, Myrt-C, and Control, respectively). In addition, since day 3 of meat storage, the lipid oxidation was improved by MR intake being lower for both MR groups than the Control (0.51 vs. 1.11 mg MDA/kg of meat). The total polyunsaturated fatty acid (PUFA) and saturated fatty acid (SFA) were similar among groups. However, the meat of Myrt-H had the highest C18:2n-6 and total PUFAn-6. In conclusion, the MR intake could be useful given it increases the meat content of vitamin E and improves its oxidative status without negative effects on the FA profile.

Production of conjugated fatty acids: A review of recent advances

Conjugated fatty acids (CFAs) have received a deal of attention due to the increasing understanding of their beneficial physiological effects, especially the anti-cancer effects and metabolism-regulation activities. However, the production of CFAs is generally difficult. Several challenges are the low CFAs content in natural sources, the difficulty to chemically synthesize target CFA isomers in high purity, and the sensitive characteristics of CFAs. In this article, the current technologies to produce CFAs, including physical, chemical, and biotechnical approaches were summarized, with a focus on the conjugated linoleic acids (CLAs) and conjugated linolenic acids (CLNAs) which are the most common investigated CFAs. CFAs usually demonstrate stronger physiological effects than other non-conjugated fatty acids; however, they are more sensitive to heat and oxidation. Consequently, the quality control throughout the entire production process of CFAs is significant. Special attention was given to the micro- or nano-encapsulation which presented as an emerging technique to improve the bioavailability and storage stability of CFAs. The current applications of CFAs and the potential research directions were also discussed.

Analysis of fatty acid profile in milk fat of Wallachian sheep during lactation

In this Research Communication we evaluate the fatty acid (FA) profile of Wallachian sheep milk. The study was performed on 38 ewes in Beskydy Mountains. Samples were collected 4 times during the lactation, at monthly intervals. FA profile as well as groups of saturated, monounsaturated (MUFA), and polyunsaturated (PUFA) FAs were investigated. Considerable increase over the lactation was detected for lauric, myristic, myristoleic and palmitic acids, while stearic acid showed the opposed tendency. Variability, supported by significant differences among particular days of milk collection, was demonstrated for oleic acid; its highest distribution occurred at the beginning and at the end of the trial. The highest distribution of CLA was at the second sample day. Milk of Wallachian sheep naturally grazed at permanent pasture areas showed higher content of PUFA and MUFA in contrast with intensive or semi-intensive sheep breeds reported in the literature.

Enhancing Omega-3 Long-Chain Polyunsaturated Fatty Acid Content of Dairy-Derived Foods for Human Consumption

Omega-3 polyunsaturated fatty acids (n-3 PUFA) are termed essential fatty acids because they cannot be synthesized de novo by humans due to the lack of delta-12 and delta-15 desaturase enzymes and must therefore be acquired from the diet. n-3 PUFA include α-linolenic acid (ALA, 18:3n-3), eicosapentaenoic (EPA, 20:5n-3), docosahexaenoic (DHA, 22:6n-3), and the less recognized docosapentaenoic acid (DPA, 22:5n-3). The three long-chain (≥C20) n-3 PUFA (n-3 LC-PUFA), EPA, DHA, and DPA play an important role in human health by reducing the risk of chronic diseases. Up to the present time, seafood, and in particular, fish oil-derived products, have been the richest sources of n-3 LC-PUFA. The human diet generally contains insufficient amounts of these essential FA due largely to the low consumption of seafood. This issue provides opportunities to enrich the content of n-3 PUFA in other common food groups. Milk and milk products have traditionally been a major component of human diets, but are also among some of the poorest sources of n-3 PUFA. Consideration of the high consumption of milk and its processed products worldwide and the human health benefits has led to a large number of studies targeting the enhancement of n-3 PUFA content in dairy products. The main objective of this review was to evaluate the major strategies that have been employed to enhance n-3 PUFA content in dairy products and to unravel potential knowledge gaps for further research on this topic. Nutritional manipulation to date has been the main approach for altering milk fatty acids (FA) in ruminants. However, the main challenge is ruminal biohydrogenation in which dietary PUFA are hydrogenated into monounsaturated FA and/or ultimately, saturated FA, due to rumen microbial activities. The inclusion of oil seed and vegetable oil in dairy animal diets significantly elevates ALA content, while the addition of rumen-protected marine-derived supplements is the most effective way to increase the concentration of EPA, DHA, and DPA in dairy products. In our view, the mechanisms of n-3 LC-PUFA biosynthesis pathway from ALA and the biohydrogenation of individual n-3 LC-PUFA in ruminants need to be better elucidated. Identified knowledge gaps regarding the activities of candidate genes regulating the concentrations of n-3 PUFA and the responses of ruminants to specific lipid supplementation regimes are also critical to a greater understanding of nutrition-genetics interactions driving lipid metabolism.

Grape pomace (Vitis vinifera L. cv. Pinotage) supplementation in lamb diets: Effects on growth performance, carcass and meat quality

This study investigated the effects of feeding graded levels of sun-dried red grape pomace (GP; 0, 5, 10, 15 and 20%) on growth, carcass and meat physico-chemical quality attributes of Dohne Merino lambs for 42 days. Dry matter intake increased quadratically with a critical value (i.e., optimum inclusion level) of 11.3% GP (P ≤ 0.05). Diet exhibited similar quadratic responses for average daily gain, live, hot and cold carcass weights with optimum inclusion levels at 9.6, 9.7, 12, 2 and 12.1, respectively (P ≤ 0.05). Overall, meat quality traits were not negatively affected by GP inclusion (P > .05). Gross profit was influenced by diet, with an optimum inclusion level at 12.2% (quadratic; P ≤ 0.05). Overall, inclusion of 12.2% GP in lamb finishing diets at the expense of oat bran and wheat bran middlings improved lamb productivity, without compromising meat quality.

Consumer Acceptability of Dry Cured Meat from Cull Ewes Reared with Different Linseed Supplementation Levels and Feeding Durations

Dry cured meat—‘cecina’—is a traditional, although not well-known, dry product that could add value to cull ewes. Because of this, the aim of the study was to assess consumer acceptability of ‘cecina’ from cull ewes finished with different levels of linseed (5, 10 or 15%) for different periods before slaughtering (30, 50 or 70 days). One hundred and fifty consumers evaluated colour acceptability, fatness and odour, flavour and overall acceptability of ‘cecina’ from those 9 treatments. Additionally, habits of consumption of cured products and preferences for different species and willingness to pay for ‘cecina’ were investigated. Linseed supplementation was identified as the most important factor for sensorial attributes (p < 0.01), with the preferred ‘cecina’ being that with 5% and 10% supplementation. Feeding duration only modified the fatness acceptability (p < 0.01). ‘Cecina’ from small ruminants is a product consumed occasionally by the majority of participants; however, it presented an adequate overall acceptability. Consequently, elaborating ‘cecina’ would be a feasible strategy to improve the income of farmers.

Effect of Dietary Grape Pomace and Seed on Ewe Milk and Meat Quality of Their Suckling Lambs

The effect of wine by-products in the feeding of ewes on fatty acid composition of milk and meat of their suckling lambs and the sensory quality of the meat was investigated. Forty-two ewes were fed during the second half of gestation and lactation one out of three treatments: a control diet based on a commercial concentrate and two concentrates supplemented with either 10% grape pomace or 5% grape seed. In addition, all animals had ad libitum access of Lucerne chaff. The control group showed lower concentration of saturated fatty acids (mainly in short and medium chain) and higher monounsaturated fatty acids (mainly oleic acid) in the milk fat, being the total polyunsaturated fatty acids unchanged. However, this variation was not reflected in the meat of the suckling lambs, where only few differences in individual fatty acids were found, such as linoleic acid being highest in the pomace treatment. Spicy and metallic flavours were increased in the wine by-products groups, but overall liking was not affected. The by-products added to the diets may be a good way to reduce costs on feeding and waste, but they were not able to provide a healthier fatty acid profile, neither in milk nor in the meat of the suckling lambs.

Nutritional enhancement of sheep meat fatty acid profile for human health and wellbeing

Dietary fatty acids (FA) consumed by sheep, like other ruminants, can undergo biohydrogenation resulting in high proportions of saturated FA (SFA) in meat. Biohydrogenation is typically less extensive in sheep than cattle, and consequently, sheep meat can contain higher proportions of omega (n)-3 polyunsaturated FA (PUFA), and PUFA biohydrogenation intermediates (PUFA-BHI) including conjugated linoleic acid (CLA) and trans-monounsaturated FAs (t-MUFA). Sheep meat is also noted for having characteristically higher contents of branched chain FA (BCFA). From a human health and wellness perspective, some SFA and trans-MUFA have been found to negatively affect blood lipid profiles, and are associated with increased risk of cardiovascular disease (CVD). On the other hand, n-3 PUFA, BCFA and some PUFA-BHI may have many potential beneficial effects on human health and wellbeing. In particular, vaccenic acid (VA), rumenic acid (RA) and BCFA may have potential for protecting against cancer and inflammatory disorders among other human health benefits. Several innovative strategies have been evaluated for their potential to enrich sheep meat with FA which may have human health benefits. To this end, dietary manipulation has been found to be the most effective strategy of improving the FA profile of sheep meat. However, there is a missing link between the FA profile of sheep meat, human consumption patterns of sheep FA and chronic diseases. The current review provides an overview of the nutritional strategies used to enhance the FA profile of sheep meat for human consumption.