Effect of dietary carnosic acid on meat quality from suckling lambs

Dietary administration of l-carnitine during the fattening period of early feed restricted lambs modifies lipid metabolism and meat quality

Early feed restriction of lambs promotes a permanent mitochondrial dysfunction that impairs β-oxidation of fatty acids along the whole life. Therefore, dietary l-carnitine might help to improve the mitochondrial function of these lambs, thus modifying lipid metabolism and meat quality traits. In order to test this hypothesis an experiment was carried out with 22 Merino lambs that were subjected to an early feed restriction during the suckling period. Once weaned, the lambs were allocated to a control group (CTRL, n = 11) being fed ad libitum a complete pelleted diet during the fattening phase, whereas the second group (CARN, n = 11) received the same diet formulated with 3 g/kg of l-carnitine. Carcass characteristics were not affected (P > 0.05) by treatment. However, lambs fed l-carnitine showed higher amounts of intramuscular fat (26.5 vs. 33.6 g/kg fresh matter; P = 0.047) with a lower ratio between polyunsaturated and saturated fatty acids (0.425 vs 0.333; P = 0.023) and a higher atherogenic (0.507 vs 0.597; P < 0.001) and thrombogenic index (1.23 vs 1.42; P < 0.001). An increase in lightness (P < 0.05) and a tendency to improved oxidative stability in cooked meat (P = 0.066) were also observed in the CARN group. Consequently, dietary l-carnitine supplied during the fattening period of early feed restricted lambs modifies meat quality traits thus increasing lightness, oxidative stability and intramuscular fat content, but worsening the fatty acid profile.

Insights into the role of major bioactive dietary nutrients in lamb meat quality: a review

Feed supplementation with α-linolenic acid (ALA) and linoleic acid (LA) increases their content in muscle, ALA increases n-3 polyunsaturated fatty acids and decrease n-6/n-3 ratio in muscle, and LA increases rumenic acid. However, high LA supplementation may have negative effects on lambs’ lipid oxidative stability of meat. When the sources of ALA and LA are fed as fresh forage, the negative effects are counterbalanced by the presence of other bioactive compounds, as vitamin E (mainly α-tocopherol) and polyphenols, which delay the lipid oxidation in meat. There is a wide consensus on the capability of vitamin E delaying lipid oxidation on lamb meat, and its feed content should be adjusted to the length of supplementation. A high dietary inclusion of proanthocyanidins, phenolic compounds and terpenes reduce the lipid oxidation in muscle and may improve the shelf life of meat, probably as a result of a combined effect with dietary vitamin E. However, the recommended dietary inclusion levels depend on the polyphenol type and concentration and antioxidant capacity of the feedstuffs, which cannot be compared easily because no routine analytical grading methods are yet available. Unless phenolic compounds content in dietary ingredients/supplements for lambs are reported, no specific association with animal physiology responses may be established.

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.

Effects of Fish Oil and Dietary Antioxidant Supplementation on Bone Health of Growing Lambs

Simple Summary

The current study investigated the bone status of growing lambs fed diets supplemented with bioactive components (fish oil, carnosic acid, SeY, and Na₂SeO₃) improving bone parameters. The study provides new information with regards to the positive role of bioactive components supplemented to diets for growing lambs on their femur characteristics (bone content, bone mineral density, geometry, and strength).

Abstract

The aim of the present study was to assess the effects of partial replacement of rapeseed oil (RO) with fish oil (FO) combined with dietary supplementation of various antioxidants on the characteristics of lamb femur. Thirty male lambs were assigned to five dietary treatments and fed isoproteinous and isoenergetic diets for 35 days. The control diet was enriched with 3.0% RO, while the experimental diets were enriched either only with 2.0% RO and 1.0% FO or additionally with 0.1% carnosic acid, 0.1% carnosic acid and 0.35 ppm Se as selenized yeast, or 0.1% carnosic acid and 0.35 ppm Se as sodium selenite. After 35 days, the lambs were slaughtered, and the femur was dissected from the carcass of each animal and analyzed for morphometric, geometric, densitometric, and biomechanical properties. The dietary modifications, specifically the supplementation of FO and selenized yeast, significantly improved the geometric, densitometric, and biomechanical properties of lamb femur.

Effects of Birth Weight on Animal Performance, Fattening Traits and Meat Quality of Lambs

Simple Summary

It is accepted that a low body weight at birth (<4 kg) might impair postnatal muscle and increase adipose tissue development during the whole life of lambs. Therefore, in the present study, we aimed to evaluate the effect of body weight at birth of lambs on the growth performance, ruminal parameters, digestibility, non-carcass components, carcass traits, physicochemical characteristics and fatty acid profile of meat when slaughtered at 27 kg. Compared to the lambs born with a high weight (>5.5 kg), the lambs born with a low body weight showed a worse animal performance during the fattening period, and increased fat depots with a higher content of saturated fatty acids and a reduced tenderness of meat.

Abstract

Intrauterine growth restriction (IUGR) is a key developmental programming factor which might impair both the feed efficiency of lambs and meat quality, since it deeply impacts skeletal muscle and adipose tissue development. To determine the effect of birth weight on the growth performance, ruminal parameters, digestibility, non-carcass components, carcass traits, physicochemical characteristics and fatty acid profile of meat, two experimental groups (six animals in each group) of male Merino lambs with different body weights (BW) at birth (low BW (LW; 3.88 ± 0.281 kg) and high BW (HW; 5.80 ± 0.647 kg)) were used. The lambs were penned with their corresponding ewe during the natural suckling period, being weaned at 15 kg. Then, the lambs were penned individually and offered a complete pelleted diet during the fattening period. All the animals were slaughtered when they reached 27 kg of BW. After weaning, both daily dry matter intake (578 vs. 615 g/day; p = 0.021) and average daily gain (141 vs. 190 g/day; p = 0.004) were significantly lower in LW lambs, and a higher feed:gain ratio was recorded for this group (3.98 vs. 3.45; p = 0.008). Carcass traits did not show differences (p > 0.05) between both groups of lambs, except for higher chilling losses for the LW group (3.29 vs. 2.69%; p = 0.012). Additionally, higher amounts of kidney knob and channel fat were observed for LW lambs (85.4 vs. 152 g; p = 0.028). Apart from a higher hardness of meat in LW lambs (152 vs. 189 Newtons, p = 0.040), no other differences (p > 0.05) were observed in the physicochemical traits of this product; however, the meat of LW lambs tended (p = 0.057) to contain more total fatty acid content with a higher (p = 0.041) proportion of saturated fatty acids than the meat of HW lambs. In conclusion, under the conditions of the present study, a low body weight at birth increased the deposition of fat in carcass and non-carcass components during the fattening period of lambs, thus reducing animal performance and worsening the nutritional indexes of the meat. Accordingly, it seems reasonable to try to identify these animals during early life, to be sold as suckling lambs in the meat market instead of being fattened.

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.