Effects of grape pomace supplementation on the diet of lactating ewes as compared to vitamin E on the meat shelf life of suckling lambs.

Forty-eight Churra ewes and their suckling lambs were assigned to four dietary treatments: control (CTRL), VIT-E (500 mg kg-1 TMR vitamin E), GP-5 (5% grape pomace) and GP-10 (10% grape pomace). After slaughter (11.5 kg live weight), longissimus muscle of lambs was sliced, packaged under modified atmosphere (80,20%/O 2:CO 2) and stored in retail conditions. At each sampling point (0, 3, 7, 10, 14 days), microbiological, physicochemical and sensory characteristics were analysed. Vitamin E and GP-5 were found to be effective (p < 0.05) at preventing enterobacteria growth as of day 10. After day 10, vitamin E and grape pomace in the ewe's supplementation reduced metmyoglobin (p < 0.05) lipid oxidation (p < 0.05) and sensory spoilage throughout the storage period. An effect of the grape pomace dosage was observed, with the supplementation at 5% being more effective. Therefore, we can conclude that grape pomace was just as effective as vitamin E in preventing spoilage during retail storage.

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.

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.

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.