Effect of sainfoin proanthocyanidins on milk fatty acids from ewes rearing suckling lambs.

Proanthocyanidins (PAC) can modulate the fatty acid (FA) profile of animal products and make them healthier for human consumption, but their effects are highly variable depending on several factors such as PAC chemical structure or dose. The present experiment aimed to evaluate the effect of PAC on the milk FA profile of Rasa Aragonesa ewes fed fresh sainfoin (PAC-containing forage legume) during the rearing period of suckling lambs (4 weeks postlambing). Twenty lactating ewes rearing a single male lamb were fed fresh sainfoin ad libitum plus 200 g/d of barley. Half the ewes were orally dosed with 100 mL of water (Sainfoin Group; n = 10) and the other half with polyethylene glycol (50 g PEG4000/100 mL water, Sainfoin + PEG Group; n = 10) to block PAC effects. Sainfoin and milk samples were collected weekly to determine their FA profile by gas chromatography. Fresh sainfoin contents of C18:3n-3 decreased from week 1 to week 2, C16:0 and C18:0 increased from week 1 to week 3, and C18:2n-6 did not change. Regarding milk FA, there were minor effects of PAC on milk-saturated FA. During the whole study, the presence of PAC increased C18:0, C18:2n-6, C18:3n-3 and total polyunsaturated FA (PUFA) n-6 and n-3, and decreased C18:1 t11, branched- and odd-chain FA. However, the decrease of milk concentrations of trans-monounsaturated FA, C18:1 t10, and total conjugated linoleic acid (CLA) and the increase of total PUFA due to the presence of PAC occurred only in week 1, while CLA c9,t11 was lower during weeks 1 and 2. The canonical analyses confirmed the differences between treatments in the FA profile of milk. Overall, the use of fresh sainfoin in the diet of lactating ewes resulted in a beneficial modification of the concentration of several milk FAs, suggesting some changes in ruminal biohydrogenation.

Effects of feeding sainfoin proanthocyanidins to lactating ewes on intake, milk production and plasma metabolites.

There is increasing interest in using sainfoin (Onobrychis viciifolia) to feed sheep, but it contains proanthocyanidins (PACs), and the associated effects of PAC on sheep production are not well-known. The aim of the study was to assess the effect of the presence of PAC from sainfoin, through the inclusion of polyethylene glycol (PEG), on the intake and productive parameters of local ewes bearing one male lamb. For the experiment, 20 ewes and their newborn male lambs were placed in individual indoor cages. All ewes were fed ad libitum fresh sainfoin plus 200 g/d barley. Twice daily, half of the ewes were orally dosed with only water (Sainfoin Group; n = 10), and the other half were orally dosed with 100 g/d PEG 4000 per ewe (Sainfoin + PEG Group; n = 10). Sucking lambs were permanently housed with their dams until they reached 10-12 kg BW. The intake of sainfoin was recorded daily, and its chemical composition was analysed. Weekly, the BW, body condition score (BCS), milk yields and individual milk and blood samples were recorded. At the beginning and end of the experiment, faecal samples were collected from ewes and analysed for the anthelmintic role of PAC. The chemical composition, polyphenol content and antioxidant capacity of the diet and milk were analysed. The presence of PAC did not affect the intake, BW, BCS or milk yield of the dams (P > 0.05); however, all parameters were affected by the week of lactation (P < 0.05). Milk components were affected by the week of lactation (P < 0.001), but only the polyphenol and urea contents were reduced in the presence of PAC (P < 0.01). Similarly, the presence of PAC decreased the plasma urea concentration (P < 0.01) without effect on the rest of metabolites, polyphenols and antioxidant activity (P > 0.05). The presence of PAC had no effect on parasitism (P > 0.05). In conclusion, the presence of PAC had no relevant effects on milk production, although it affected protein metabolism, as indicated by the urea contents in milk and plasma.

Malondialdehyde determination in raw and processed meat products by UPLC-DAD and UPLC-FLD.

The objective of this study was to develop an accurate and fast method to determine malondialdehyde (MDA) levels in raw and processed meat. This method is based on extraction with trichloroacetic acid (TCA), reaction with 2-thiobarbituric acid (TBA) and quantification with ultraperformance liquid chromatography with a fluorescence detector (UPLC-FLD) with ʎexcitation = 530 nm and ʎemission = 550 nm and with a diode array detector (UPLC-DAD) with ʎabsorbance = 532 nm. The method tested was compared with the TBARS spectrophotometric method with ʎabsorbance = 532 nm. The concentration of MDA was similar for most of the matrices in both UPLC methods, except for cooked ham and frankfurter sausage. The TBARS spectrophotometric method overestimated the MDA concentration in all the matrices. Therefore, the use of both chromatographic methods, especially UPLC-FLD, to determine MDA would be more advisable than the classic TBARS method to avoid overestimation in meat and processed meat products.

Simultaneous determination of carotenoids, tocopherols, retinol and cholesterol in ovine lyophilised samples of milk, meat, and liver and in unprocessed/raw samples of fat.

An accurate, fast, economic and simple method to determine carotenoids, tocopherols, retinol and cholesterol in lyophilised samples of ovine milk, muscle and liver and raw samples of fat, which are difficult to lyophilise, is sought. Those analytes have been studied in animal tissues to trace forage feeding and unhealthy contents. The sample treatment consisted of mild overnight saponification, liquid-liquid extraction, evaporation with vacuum evaporator and redissolution. The quantification of the different analytes was performed by the use of ultra-high performance liquid chromatography with diode-array detector for carotenoids, retinol and cholesterol and fluorescence detector for tocopherols. The retention times of the analytes were short and the resolution between analytes was very high. The limits of detection and quantification were very low. This method is suitable for all the matrices and analytes and could be adapted to other animal species with minor changes.

Rosemary distillation residues reduce lipid oxidation, increase alpha-tocopherol content and improve fatty acid profile of lamb meat.

The experiment studied the effects of rosemary distillation residues (RR) intake on lamb meat quality, oxidative stability and fatty acid (FA) profile. Barbarine lambs of Control group were fed 600g of hay, which was substituted by 600g of pellets containing 60 and 87% of RR for RR60 and RR87 groups; all animals received 600g of concentrate. Meat protein and fat content was similar for 3 treatments. Lipid oxidation was strongly reduced with RR diets. Both RR diets resulted in a higher α- tocopherol content in muscle. The metmyoglobin and deoxymyoglobin percentages were similar for all groups; however oxymyoglobin was higher for RR groups. The saturated (SFA) and unsaturated FAs (UFA) were unaffected by the diets. However, the PUFA, n-6 and n-3 were higher for RR groups. In conclusion, rosemary residues resulted in higher vitamin E content, so it enhanced the oxidative status and improved the fatty acid profile of lamb meat.

Meat quality of light lambs is more affected by the dam's feeding system during lactation than by the inclusion of quebracho in the fattening concentrate.

The inclusion of natural antioxidants in the diet, through fresh forages or condensed tannins, might prolong meat shelf life and modify the meat quality. The aim of this study was to evaluate the effect of the dam's feeding system during lactation and the inclusion of quebracho in the fattening concentrate of male lambs on meat color, chemical composition, and lipid oxidation. Dams and their suckling lambs were fed indoors or allowed to graze on alfalfa or sainfoin until lambs reached 42 d old. Thereafter, the weaned lambs were fed concentrates with 5% quebracho or without quebracho until reaching 22 to 24 kg BW. Meat of suckling lambs from dam's fed indoors (Indoor lambs) presented greater intramuscular fat content and lower α-tocopherol content than meat of suckling lambs from dam's fed Alfalfa (Alfalfa lambs) and Sainfoin (Sainfoin lambs; < 0.01), independent of the fattening diet. Regarding meat color of longissimus thoracis et lumborum muscle, on average, Indoor lambs' meat presented greater lightness, yellowness, and hue angle values than Alfalfa and Sainfoin lambs' meat ( < 0.05). The redness was affected by the interaction between the feeding system during lactation and the time of storage, but, on average, Alfalfa and Sainfoin lambs had greater redness than Indoor lambs ( < 0.05). The lipid oxidation from 5 to 14 d of meat display time observed for Sainfoin lambs was lower than that for Indoor lambs ( < 0.05). The intramuscular fatty acid profile of meat from the Sainfoin and Alfalfa lambs met particularly well the Food and Agriculture Organization of the United Nations recommendation for human health, compared that of meat from the Indoor lambs. The dietary inclusion of quebracho during fattening modified meat α-tocopherol content, oxymyoglobin levels after 8 d of storage, and fatty acid profiles. In conclusion, the results indicate higher importance of the diet during suckling than during the subsequent fattening period on meat quality parameters such as color, lipid oxidation, and fatty acid profile. Dams grazing Sainfoin provide a more stable lamb meat, and it would be cheaper to feed the dams with fresh forages with a high α-tocopherol content than supplementing the concentrate of the lambs with synthetic α-tocopherol.