Teresa Manso

FATTY ACID COMPOSITION AND CARCASS CHARACTERISTICS OF GROWING LAMBS FED DIETS CONTAINING PALM OIL SUPPLEMENTS

Thirty 45-day-old male Ojalada lambs were used to investigate the effect of palm oil (as such or in the form of calcium soap) on carcass characteristics and fat composition. Dietary palm oil did not significantly affect dorsal fat thickness, carcass fatness or carcass conformation. The palm oil supplement did not affect C16:0 levels in intramuscular and subcutaneous fat, but did increase the percentage of C16:0 and reduce PUFA and MUFA content in internal fat depots. Supplementation with palm oil in the form of calcium soap did not cause significant differences in the composition of intramuscular fat. Subcutaneous and perirenal fat of lambs fed treatments including palm oil as such contained higher levels of some saturated fatty acids than that of those fed fat in the form of calcium soap. Mesenteric fat of lambs that received calcium soap had less % C18:1 and more % C18:3 than that of those given palm oil.

Animal performance and fatty acid composition of lambs fed with different vegetable oils.

Twenty-seven lambs were used to investigate the effects of the inclusion of 4% hydrogenated palm oil (HPO) or sunflower oil (SFO) in the concentrate on animal performance, carcass and meat quality and fat characteristics and fatty acid composition. Animals (16.2±0.27kg initial weight) were fed concentrate (Control, HPO or SFO) and barley straw ad libitum and slaughtered at 25kg. SFO lambs tended to eat less concentrate than HPO animals (P<0.10). Neither HPO nor SFO affected any of the carcass characteristics studied, meat pH and meat and fat colour (P>0.05). SFO decreased proportions of C16:0, C18:1 cis-11 and C18:3 (P<0.05) and increased C18:1 trans (P<0.001) and C18:2/C18:3 ratio (P<0.05). Atherogenicity index was lower (P<0.05) when SFO was included in the concentrate. HPO did not affected and SFO improved fatty acid composition of fattening lambs without affecting animal performance.

Feeding vegetable oils to lactating ewes modifies the fatty acid profile of suckling lambs.

The objective of this study was to evaluate the effects of vegetable oil supplementation of ewe diets on the performance and fatty acid (FA) composition of their suckling lambs. Forty-eight pregnant Churra ewes (mean BW 64.3±0.92 kg) with their 72 newborn lambs (prolificacy=1.5) were assigned to one of four experimental diets, supplemented with 3% of hydrogenated palm (PALM), olive (OLI), soya (SOY) or linseed (LIN) oil. Lambs were nourished exclusively by suckling from their respective mothers. Ewes were milked once daily, and milk samples were taken once a week. When lambs reached 11 kg, they were slaughtered and samples were taken from musculus longissimus dorsi (intramuscular fat) and subcutaneous fat tissue. No changes were observed in milk yield, proximal composition or lamb performance (P>0.10). Milk and lamb subcutaneous and intramuscular fat samples from the PALM diet had the highest saturated fatty acid concentration, whereas those of the OLI, SOY and LIN diets had the lowest (P<0.05). The greatest monounsaturated fatty acid concentration was observed in milk from ewes fed OLI, and the least in milk and in lamb subcutaneous and intramuscular fat samples from LIN and PALM diets. Milk and lamb fat from ewes fed PALM displayed the highest 16:0 proportion and the lowest 18:0 (P<0.05). There were higher concentrations of cis-9 18:1 in OLI samples (P<0.05), more 18:2n-6 in SOY lambs and milk fat (P<0.001) and the highest levels of 18:3n-3 and 20:5n-3 in LIN samples (P<0.01). Milk and lamb subcutaneous and intramuscular samples from SOY and LIN diets contained the most cis-9, trans-11 conjugated linoleic acid, whereas PALM samples had the least (P<0.01). Sheep diet supplementation with different oils, constituting up to 3% of their diets, resulted in changes in the FA composition of milk and the subcutaneous and intramuscular fat of suckling lambs, but did not affect either milk production or lamb performance.

Effects of linseed oil and natural or synthetic vitamin E supplementation in lactating ewes' diets on meat fatty acid profile and lipid oxidation from their milk fed lambs.

Forty-eight Churra ewes with their new-born lambs were separated into four dietary treatments: Control (without added fat), LO (with 3% linseed oil), LO-Syn E (LO plus 400 mg/kg TMR of synthetic vitamin E) and LO-Nat E (LO plus 400 g/kg TMR of natural vitamin E). Linseed oil caused an increase in trans-11 C18:1 (VA), trans-10 C18:1, cis-9, trans-11 C18:2 (RA), trans-10, cis-12 C18:2 and C18:3 n-3 (ALA) in milk fat compared to the Control. The addition of vitamin E to the LO diets did not influence significantly the majority of milk fatty acids compared with the LO diet alone. Trans-10 C18:1, VA, RA, trans-10, cis-12 C18:2 and LA levels were higher in intramuscular lamb fat from treatments with linseed oil. No statistically significant differences were observed in these FA due to vitamin E supplementation or the type of vitamin E (synthetic vs. natural). Vitamin supplementation resulted in lipid oxidation levels below the threshold values for detection of rancidity in lamb meat.

Effects of grape pomace in growing lamb diets compared with vitamin E and grape seed extract on meat shelf life.

The effect of dietary treatment (CTRL, control; VIT-E, 500 mg kg(-1) vitamin E; GSE, 50 mg grape seed extract kg(-1); GP-5, 5% dried red grape pomace kg(-1)) on shelf life of lamb meat was studied. After slaughter (27 kg LBW), m. longissimus thoracis et lumborum was sliced, packaged under modified atmosphere (80:20%/O2:CO2) and stored in retail conditions for 14 days. At each sampling day (0, 4, 7, 11, 14), microbiological, physico-chemical and sensory characteristics were analysed. Meat from VIT-E presented lower microbial counts than CTRL, GSE and GP-5, without differences between polyphenol treatments (GSE and GP-5) and CTRL. Vitamin E reduced meat discoloration and lipid oxidation (TBARS values) from day 7 with respect to the other treatments. Although not significant, an improvement in TBARS values of about 20% was observed for GSE and GP-5, compared with CTRL, from day 7 of storage. VIT-E dietary treatment was more effective in preventing sensory spoilage than the other treatments.

Effects of different sources of fat (calcium soap of palm oil vs. extruded linseed) in lactating ewes' diet on the fatty acid profile of their suckling lambs

The main objective of this study was to evaluate the effects of supplementing lactating ewe diets with extruded linseed on the fatty acid (FA) composition of intramuscular and subcutaneous fat depots of suckling lambs. Twenty-four pregnant Churra ewes were divided into two groups based on the milk production, age, body weight and parity, and assigned to one of two treatments. Each ewe of the Control treatment was supplemented with 70 g/day of FAs from a calcium soap of palm oil, while the other treatment group (Lin) was supplemented with 128 g/day of extruded linseed. All lambs were reared exclusively on milk and were slaughtered when they reached 11 kg live weight. FA profiles of ewe milk, lamb meat and subcutaneous adipose tissue were determined by GC. Lamb performance was not affected by the treatments. Muscle fat and adipose tissue from the Lin treatment showed higher proportions of polyunsaturated fatty acids (PUFA). The percentages of α-linolenic (C18:3 n-3), docosahexaenoic (C22:6 n-3), vaccenic (trans-11 C18:1) and rumenic (cis-9, trans-11 C18:2) acids in both fat depots were higher in Lin than in Control suckling lambs. Furthermore, meat fat from Lin carcasses displayed a lower n-6/n-3 ratio than Control samples. Intramuscular depots clearly showed a greater content of PUFA, including cis-9, trans-11 C18:2, and a lower n-6/n-3 ratio than subcutaneous fat. The results from this study demonstrate that dietary extruded linseed supplementation of lactating ewes enhances the nutritional quality of suckling lamb fat depots such as intramuscular and subcutaneous fats.

Effects of olive and fish oil Ca soaps in ewe diets on milk fat and muscle and subcutaneous tissue fatty-acid profiles of suckling lambs.

Enhancing healthy fatty acids (FAs) in ewe milk fat and suckling lamb tissues is an important objective in terms of improving the nutritional value of these foods for the consumer. The present study examined the effects of feeding-protected lipid supplements rich in unsaturated FAs on the lipid composition of ewe milk, and subsequently in the muscle and subcutaneous adipose tissues of lambs suckling such milk. Thirty-six pregnant Churra ewes with their new-born lambs were assigned to one of three experimental diets (forage/concentrate ratio 50 : 50), each supplemented with either 3% Ca soap FAs of palm (Control), olive (OLI) or fish (FO) oil. The lambs were nourished exclusively by suckling for the whole experimental period. When the lambs reached 11 kg BW, they were slaughtered and samples were taken from the Longissimus dorsi and subcutaneous fat depots. Although milk production was not affected by lipid supplementation, the FO diet decreased fat content (P0.05) and other trans-FAs between Control and FO treatments would indicate that FO treatment does not alter rumen biohydrogenation pathways under the assayed conditions. Changes in dam milk FA composition induced differences in the FA profiles of meat and fat depots of lambs, preferentially incorporated polyunsaturated FAs into the muscle rather than storing them in the adipose tissue. In the intramuscular fat of the FO treatment, all the n-3 FAs reached their highest concentrations: 0.97 (18:3 n-3), 2.72 (20:5 n-3), 2.21 (22:5 n-3) and 1.53% (22:6 n-3). In addition, not only did FO intramuscular fat have the most cis-9, trans-11 18:2 (1.66%) and trans-11 18:1 (3.75%), but also the lowest n-6/n-3 ratio (1.80) and saturated FA content were not affected. Therefore, FO exhibited the best FA profile from a nutritional point of view.

Influence of dietary grape pomace combined with linseed oil on fatty acid profile and milk composition

Grape pomace is a by-product resulting from the winery industry that is rich in phenolic compounds. It could play a role as an antioxidant and, owing to its high fiber concentration, it would be an alternative ingredient to partially replace forage in the diet of small ruminants. The objective of this study was to evaluate the effect of dietary supplementation of vitamin E or different doses of grape pomace associated with linseed oil on milk fatty acid profile, composition, and yield. Forty-eight Churra ewes were fed with experimental diets consisting of a total mixed ration (TMR) containing 2.7% [on a dry matter (DM) basis] of linseed oil, forage, and concentrate at a 40:60 ratio. Ewes were assigned to 1 of 4 treatments: control (without grape pomace), vitamin E (with 500 mg/kg of TMR of vitamin E), grape pomace-5 (5 g/100 g of TMR of DM of grape pomace), and grape pomace-10 (10 g/100 g of TMR of DM of grape pomace). Experimental diets did not affect DM intake and milk yield and composition. The vitamin E supplementation had only a moderate effect on milk concentration of fatty acids (increase in α-linolenic acid and 16:0 and decrease in cis-9 18:1). Grape pomace supplementation did not affect the percentages of total saturated, monounsaturated, and polyunsaturated fatty acids. Levels of α-linolenic acid reached about 1% of total fatty acids as a consequence of the presence of linseed oil in the diets, were not modified with vitamin E, and remained unaltered in grape pomace-5 and -10 treatments. Linoleic acid was increased by the highest dose of grape pomace, but this ingredient did not modify the cis-9,trans-11 18:2 milk fat content. The concentration of total odd- and branched-chain fatty acids did not diminish in grape pomace-5 and pomace-10 treatments. The presence of grape residue did not modified the trans-11 18:1 and trans-10 18:1 contents, which might indicate that, under the conditions assayed, this winery by-product would not alter the pathways of rumen conversion of dietary unsaturated fatty acids.

Evaluation of grape pomace from red wine by-product as feed for sheep

BACKGROUND This work aimed to study the chemical composition and in vitro digestibility of seeds and pulp from grape pomace. In sacco degradability, ruminal fermentation of grape pomace fractions and plasma lipid peroxidation were also studied in sheep fed with or without grape pomace. RESULTS Seed and pulp fractions of grape pomace had different values for cell walls (523 vs 243 g kg-1 dry matter (DM)), crude protein (CP, 104 vs 138 g kg-1 DM), ether extract (EE, 99.0 vs 31.7 g kg-1 DM), polyunsaturated fatty acids (PUFA, 69.6 vs 53.3%) and extractable polyphenols (55.0 vs 32.1 g kg-1 DM). The in vitro true digestibility, DM in sacco degradability and CP degradability of seeds and pulp were also different (0.51 vs 0.82, 0.30 vs 0.45 and 0.66 vs 0.39 respectively). The ammonia-N concentration and total volatile fatty acids (VFA) in ruminal liquid were significantly lower and plasma lipid peroxidation was also numerically lower in sheep that consumed grape pomace. CONCLUSION The nutritive value of grape pomace varies depending on the proportion of seeds and pulp. The interest of this by-product in sheep feeding could be related to its polyphenol and PUFA content, which could improve meat and milk quality.

Grape pomace in ewes diet: Effects on meat quality and the fatty acid profile of their suckling lambs

Grape pomace (GP) is an inexpensive natural antioxidant promising as animal feed supplement due to its high content of phenolic compounds. In order to evaluate its effect in lactating ewe rations on meat quality and fat composition of their suckling lambs, 48 Churra ewes were divided into 4 treatments. All animals were fed a ration containing linseed oil (Control) supplemented with Vitamin E or two levels of GP. Lambs were nourished exclusively by suckling until they were slaughtered. Dietary GP did not generate adverse effects on carcasses or lambs meat quality when compared with Control or Vit-E diets. GP improved the water holding capacity of the meat. In addition, lambs meat FA profile was not nutritionally affected with the diets assayed. Hence, the use of GP as a dietary supplement in ewe rations would not have negative effects on meat from suckling lambs.