Effects of the rearing season on carcass and meat quality of suckling Apennine light lambs

The aim of this study was to evaluate the effects of the rearing season (autumn vs winter) on the carcass and meat quality of light lambs, obtained according to the traditional farming system usual in central Italy. Eighty carcasses from 60 d ± 3 old unweaned Apennine single birth male lambs, permanently reared indoor, half in autumn (receiving milk from ewes permanently pastured) and half in winter (which dams did never acceded to pasture), were weighed, classified according to the EU classification system for light lambs, and their Longissimus lumborum meat was analysed for pH, colour, drip and cooking losses, proximate composition and fatty acids profile of intramuscular fat. Most of the carcasses fully responded to the 1st quality EU requirements and no effects of the rearing season was evident on carcass characteristics. On the contrary, L. lumborum of lambs born and reared in autumn, receiving milk from ewes permanently pastured, evidenced a lower Lightness L* (P = 0.02), a higher Chroma C* (P = 0.01), with a higher fat content (P = 0.04) than lambs reared in winter, which dams were permanently stall-fed. Moreover the intramuscular fat of the former was characterized by a greater PUFA concentration (P = 0.01), a more favourable n-6/n-3 ratio (P < 0.001), and a higher CLA content (P < 0.001) than the latter, as a result of the difference related to the sheep traditional feeding system.     

Different oilseed supplements alter fatty acid composition of different adipose tissues of adult ewes

Twenty-five mature Small Tail Han ewes were used to investigate the effects of supplemental oilseeds in the diet (sunflower seed, safflower seed, rapeseed, and linseed) on fatty acid composition in different tissues (longissimus lumborum muscle, tail fat, subcutaneous back fat and kidney fat). Averaged over tissue, safflower and sunflower seed was most effective (P < 0.05) in enhancing the concentration of conjugated linoleic acid compared to rapeseed, linseed, and control (1.35% and 1.15% vs. 0.80%, 0.80%, and 0.75%, respectively). Linseed supplemented ewes had lesser n−6/n−3 value (2.48, P < 0.05) compared to sunflower and safflower supplemented ewes (6.12 and 3.90, respectively). Fatty acid composition for most major fatty acids differed among tissues (P < 0.05) but tissue differences varied depending on oilseed supplement (P < 0.05). Proportions of conjugated linoleic acid were greatest in tail fat (1.54% vs. 0.82%, 0.79% and 0.70% for kidney, back, and muscle fat, P < 0.05) as were total unsaturated fatty acids (49.1% vs. 42.4%, 36.7% and 33.4% for muscle, back, and kidney fat, P < 0.05) and tail fat was the most responsive tissue to improvement in fatty acid profile through supplementation. Beneficial fatty acid content of tissues can be increased by oilseed supplementation, but the magnitude of increase varies according to tissue.     

Antioxidant status,colour stability and myoglobin resistance to oxidation of longissimus dorsi muscle from lambs fed a tannin-containing diet

Fourteen lambs were individually penned for 60 days. Seven lambs (C) were fed a barley-based concentrate, while 7 animals (T) received the same concentrate supplemented with 8.96% (dry matter basis) quebracho (Schinopsis lorentzii) extract. Tannin supplementation extended colour stability of fresh longissimus dorsi muscle (LM) over 7 days of aerobic storage with lower changes in hue angle over time in LM from T-fed animals compared to C-fed lambs (P = 0.032). Muscle from T-fed lambs had lower metmyoglobin percentages (MMb%) than that from C-fed animals after 3 days of storage (P = 0.05) and tended to have slower rates of change in (K/S)₅₇₂ ÷ (K/S)₅₂₅ values (P = 0.07). Compared to the C diet, tannin supplementation increased the concentration of total phenols in muscle (+31.29%, P = 0.001) and resulted in a higher muscle antioxidant capacity measured by FRAP (+16.81%, P = 0.026) and TEAC (+24.81%, P = 0.001) tests. Furthermore, feeding tannins resulted in lower MMb% after nitrite-induced oxidation measured both at the meat surface (−10%, P = 0.012) and in a meat extract (−8.22%, P = 0.004).     

Effect of sire breed on physico-chemical and sensory characteristics of lamb meat

Physico-chemical and sensory characteristics of lamb meat were evaluated in crossbred ram lambs from Merino ewes and Oxford Down, Texel, Charollais, Suffolk and Merinolandschaf sires. The lambs were slaughtered at average age 119.2 days, live weight 34.6 kg and carcass weight 16.3 kg. Samples of M. longissimus lumborum et thoracis were used for measurements of pH values, electrical conductivity (EC), drip loss, contents of dry matter (DM), protein, intramuscular fat (IMF), ash, and hydroxyproline and for sensory analysis. The breed of sire significantly affected pH 24 and 48 h postmortem, EC 24 h postmortem, protein content and juiciness (P < 0.05). Significant negative correlations between pH₄₈ and DM (− 0.255) and pH₄₈ and IMF (− 0.258) were found (P < 0.05). A significant positive correlation between EC₄₈ and drip loss (0.366) was observed (P < 0.05). Progeny of Charollais sires had meat of better quality than the others; the highest content of protein and IMF, the lowest drip loss and the best juiciness and texture.     

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 ± 0.27 kg initial weight) were fed concentrate (Control, HPO or SFO) and barley straw ad libitum and slaughtered at 25 kg. 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.     

Influence of feeding systems on cortisol levels,fat colour and instrumental meat quality in light lambs

Forty-eight lambs were fed as follows: GR, lambs and dams grazed perennial pasture; GR+S, the same as GR except that lambs had access to concentrate; DRL-GRE, lambs in drylot and dams in rationed grazing; DRL, lambs with dams were stall-fed. DRL-GRE and DRL lambs were weaned at 45 days of age. Lambs were slaughtered when they reached 22–24 kg of live weight. Plasma cortisol concentration was determined three times before slaughter. Subcutaneous fat and meat colour, and texture were analysed.     

The effect of the change from a herbage- to a concentrate-based diet on the oxidative stability of raw and cooked lamb meat

Over 89 days, 10 lambs (S) were fed concentrates and hay in stall, while 9 lambs (P) grazed at pasture. Two groups of 9 animals grazed at pasture until switching to a concentrate-based diet for 14 or 37 days before slaughter (P-S14 and P-S37). The fat content of longissimus dorsi muscle (LM) increased with increasing duration of concentrate feeding (P = 0.05). As a consequence, the concentration of polyunsaturated fatty acids (PUFA) and of the highly peroxidisable (HP) PUFA in the polar lipids was similar between treatments. Lipid oxidation in fresh LM over 8 days of storage was affected by the diet (P < 0.0005) with the P-S37 and P treatments producing, respectively, the highest and the lowest TBARS values. The P treatment reduced TBARS in cooked minced LM over 2 days of storage and no difference was found between the P-S14, P-S37 and S treatments. Colour stability of fresh LM was not noticeably affected by the dietary treatment.     

Effects of linseed and quercetin added to the diet of fattening lambs on the fatty acid profile and lipid antioxidant status of meat samples

Thirty-two Merino lambs fed barley straw and a concentrate formulated either with palm oil (CTRL group) or with linseed (+ LS group), both alone or supplemented with quercetin (+ QCT group or + LS + QCT group) were used to assess the effects of these dietary supplements on meat quality attributes. After being slaughtered, the longissimus thoracis muscles were used to study the fatty acid (FA) profile in detail, whilst longissimus lumborum slices were stored under refrigerated conditions to determine the lipid stability. Linseed increased the content of highly unsaturated n − 3 long-chain fatty acid (20:5n − 3; 22:5n − 3; 22:6n − 3). Interestingly, a significant increment of rumenic acid content (9c,11t-18:2) was observed when this seed was administered together with dietary quercetin. Moreover, the feeding of quercetin resulted in a reduction in the proportion of saturated FA and a decrease in lipid peroxidation of meat when the lambs were fed linseed. In conclusion, from both a nutritional and a commercial (shelf-life) point of view, it may be useful to include a source of quercetin when lambs are fed linseed diets.     

Sensory,physical and chemical characteristics of cooked ham manufactured from rapidly chilled and earlier deboned M. semimembranosus

Effects of rapid chilling of carcasses (at − 31 °C in the first 3 h of chilling, and then at 2–4 °C) and earlier deboning (8 h post-mortem), compared to rapid (till 24 h post-mortem) and conventional chilling (at 2–4 °C, till 24 h post-mortem), on quality characteristics of pork M. semimebranosus and cooked ham were investigated. Quality measurements included pH value, colour (CIEL*a*b* values) and total aerobic count of M. semimebranosus, as well as sensory (colour, juiciness, texture, and flavour), physical (pH value, colour – CIEL*a*b* values and texture – Warner–Bratzler shear and penetration forces) and chemical (protein, total fat, and moisture content) characteristics of cooked ham. The cooked ham was manufactured from pieces of M. semimebranosus with ultimate lightness (CIEL* value) lower than 50. Rapid chilling and earlier deboning significantly increased quantity of M. semimebranosus desirable for cooked ham manufacturing. Earlier start of pork fabrication did not affect important quality characteristics of cooked ham.     

Effect of supplementation of grazing dairy ewes with a cereal concentrate on animal performance and milk fatty acid profile

This work was conducted to investigate the effect of supplementing grazing ewes on pasture with a cereal concentrate on the milk fatty acid (FA) profile. Ninety Assaf ewes in mid lactation were distributed in 9 lots of 10 animals each and allocated to 3 feeding regimens: 1) pasture—ewes were only allowed to graze pasture (an irrigated sward of Lolium perenne, Trifolium pratense, and Dactylis glomerata); 2) PS—grazing ewes were supplemented with oat grain (700 g/animal and day); and 3) TMR—ewes were fed ad libitum a total mixed ration (TMR; 80:20 concentrate/forage ratio). Milk yield and composition were recorded for 5 wk. The highest milk yield was observed in ewes receiving the TMR and the lowest in grazing ewes supplemented with oat grain. Productions of milk fat, protein, and total solids showed the lowest values in treatment PS. The atherogenicity index, which comprises C12:0, C14:0, and C16:0, in PS milk fat was no different from that observed in milk from animals on pasture (1.53 for pasture, 1.54 for PS, and 3.22 for TMR). Oat grain supplementation generated higher amounts of C18:0 and cis-9 C18:1 in milk fat than the pasture-only diet, but significantly decreased the levels of α-linolenic acid and most of intermediates of the process of biohydrogenation of this FA. Cis-9 trans-11 C18:2 and trans-11 C18:1, its precursor for endogenous synthesis in the mammary gland, were lower in PS (0.58 and 1.59 g/100 g of total FA) than in TMR (0.72 and 1.92 g/100 g of total FA) and very different from the results observed in grazing ewes receiving no supplement (1.21 and 3.88 g/100 g of total FA). Furthermore, the lowest levels of trans-10 C18:1 and trans-10 cis-12 C18:2 were detected in the milk fat of ewes fed pasture. It is concluded that, when pasture quality and availability do not limit dairy production, supplementation of grazing ewes with oat grain compromised the milk FA profile without any significant positive effect on milk production.     

Effect of the dietary supplementation of essential oils from rosemary and artemisia on muscle fatty acids and volatile compound profiles in Barbarine lambs

Eighteen Barbarine lambs (3 months of age), were assigned for 95 days to 3 treatments: six lambs were fed a barley-based concentrate plus oat hay ad libitum (control group, C); other lambs received the control diet plus essential oil (400 ppm DM) either of Rosmarinus officinalis (R400 group; n = 6) or of Artemisia herba alba (A400 group; n = 6). At slaughter the muscle longissimus dorsi was sampled and subjected to fatty acid and volatile organic compounds (VOC) analyses. The A400 lambs presented a greater amount of vaccenic, rumenic and linolenic acids and of polyunsaturated fatty acids (PUFA) in meat than the C and R400 animals. Essential oils supplementation did not affect meat VOC profile though the sesquiterpenes copaene and β-caryophyllene were detected only in the meat of R400 and A400 lambs. It is concluded that the supplementation of rosemary or artemisia essential oils does not produce detrimental effects on lamb meat VOC profile. The supplementation of artemisia can improve meat healthy properties.     

Δ desaturase protein expression and fatty acid composition of longissimus dorsi muscle in lambs fed green herbage or concentrate with or without added tannins

The aims of this study were to investigate the effect of feeding system and of supplementation of tannins (8.93% DM) on the relationship between intramuscular fat content, fatty acid composition and Δ⁹desaturase (Δ⁹d) protein expression in longissimus dorsi muscle of lamb. Twenty-eight Comisana lambs (age 45 days) were fed either vetch (Vicia sativa) or concentrate. The herbage diet was (i) lower in saturated fatty acids (especially in C16:0), C18:1 n−9 and in C18:2 n−6; (ii) higher in C16:1 and C18:3 n−3 when compared to concentrate. Within each feeding system the lambs were divided into two sub-groups, one of which received the diet without tannins supplementation, and the other was fed the diets supplemented with the tannins from Quebracho (Schinopsis lorentzii). The animals were slaughtered at age 105 days. The concentrate feeding system increased (p < 0.01) the total intramuscular fat content and the amount of SFA, MUFA and n−6 PUFA and decreased the level of n−3 PUFA (p = 0.05) when compared to the vetch-fed animals but did not affect Δ⁹ desaturase protein expression. There was no correlation between Δ⁹d protein expression and total intramuscular fatty acids, CLA and MUFA level. It was suggested that in ruminants, in contrast to monogastric animals, Δ⁹d expression does not play the key role in intramuscular fatty acids formation. Tannins supplementation resulted in higher (p < 0.05) muscle levels of transC18:1 and C18:2 n−6. It has also increased Δ⁹d expression in the case of herbage-based diet but not in the case of concentrate-based diet. The mechanism of tannins action on the enzyme expression needs to be elucidated.     

Quality characteristics and composition of the longissimus muscle in the short-loin from male and female farmed red deer in New Zealand

Meat quality and composition characteristics are reported for the longissimus muscle from 10 red deer stags and 10 hinds aged about 20 months. All animals were pasture-finished but the stags and hinds came from different farms. The average carcass weight was 3.4 kg greater for the stag group (55.8 vs 52.4 kg; P = 0.04), but measures of GR as a measure of fatness were similar and intramuscular fat content was significantly greater for the hind group (1.12% vs 0.63%; P < 0.0001), as expected. The tenderness of cooked venison in terms of shear force and compression measures was significantly better for venison from the hind group, possibly due to the greater amount of intramuscular fat and slightly longer sarcomeres. The gender groups did not differ in absolute measures of colour or in the rate at which it deteriorated on display. However, the rate of colour deterioration was more rapid than other meats such as beef, as has been demonstrated elsewhere. The average ultimate pH and water-holding capacity were similar for the two groups. Venison from hinds contained more coenzyme Q₁₀, taurine, anserine, carnosine, and vitamin E. Group differences in fatty acid composition of intramuscular fat appeared to be mainly due to levels of fatness, which was greater for the hind group.     

Effects of refrigeration,freezing and replacement of milk fat by inulin and whey protein concentrate on texture profile and sensory acceptance of synbiotic guava mousses

The effects of refrigeration, freezing and substitution of milk fat by inulin and whey protein concentrate (WPC) on the texture and sensory features of synbiotic guava mousses supplemented with the probiotic, Lactobacillus acidophilus La-5, and the prebiotic fibre oligofructose, were studied. The frozen storage (−18 ± 1 °C), followed by thawing at 4 °C before the analyses, and the complete replacement of the milk fat by inulin plus WPC, led to significant differences in the instrumental texture parameters of mousses (P < 0.05). Nonetheless, these changes did not affect the sensory acceptability of the products studied. The frozen storage may be employed to extend the shelf-life of synbiotic guava mousses. Additionally, to obtain a texture profile similar to the traditional product, the simultaneous addition of inulin and WPC is recommended only for the partial replacement of milk fat in refrigerated and frozen mousses, and the total proportion of both ingredients together should not exceed 2.6%.     

Effect of dietary carnosic acid on the fatty acid profile and flavour stability of meat from fattening lambs

Thirty-two lambs were fed with barley straw supplemented by a concentrate alone, or a concentrate enriched with either vitamin E (VITE006: 0.6 g kg⁻¹ feed concentrate) or carnosic acid (CARN006: 0.6 g kg⁻¹ feed concentrate; or CARN012: 1.2 g kg⁻¹ feed concentrate). In order to elucidate the influence of the dietary supplementation of carnosic compared with a reference diet antioxidant (vitamin E), the animals were slaughtered and the longissimus thoracis were lyophilised to determine the FAs profile and the phenolic compounds. In addition, longissimus lumborum slices were stored in a modified atmosphere package for 3 days and then grilled to determine volatile compounds. Dietary carnosic acid did not modify the FAs profile, but had a clear effect on the production of volatile compounds, in a dose-dependent manner. These results have implications for the food industry, since dietary carnosic acid seems to extend the shelf life of lamb meat.     

Effect of lamb age and retail packaging types on the quality of long-term chilled lamb loins

The objective of this study was to determine the impact of lamb age and packaging types on meat quality. Paired loins (M. longissimus dorsi) were obtained from 36 carcasses that included 4-month-old (New season; NS) and 11-month-old lambs (Old season; OS). The loins were vacuum-stored for eight weeks at − 1.5 °C. After storage, the loins were cut into subsamples and were randomly assigned to either high-oxygen modified atmosphere packaging (HiOx-MAP) or PVC-overwrapping for further display for 8 days. No differences between the age classes in shear force and drip loss were found (P > 0.05). OS loins had significantly higher myoglobin and redness compared with NS loins. HiOx-MAP initially induced a more intense red colour compared with PVC (P < 0.05), but resulted in severe discolouration at the end of display regardless of the age class. This observation suggests that the retail packaging type is the dominant factor over the age on lamb colour stability.     

Effect of suckling management on productive performance,carcass traits and meat quality of Comisana lambs

The effect of restricted suckling on productive performance, carcass traits, meat quality and skeletal development of growing lambs was studied. Twenty-one naturally suckled male Comisana lambs were divided into three equal weight groups differing in suckling management systems: (1) only maternal milk (C); (2) only maternal milk until 15th day of age, and then, till slaughter, maternal milk, concentrate and Lucerne hay ad libitum (T1); (3) only maternal milk until 15th day of age, and then from 16th to 30th days of age, maternal milk, concentrate and Lucerne hay ad libitum, and, from 31st day of age till slaughter, only concentrate and Lucerne hay ad libitum (T2). The total mean milk yield was 22.7 and 41.6 kg per ewe for T1 and T2, respectively. Restricted suckling did not significantly affect slaughter weight, hot and cold carcass weights, carcass shrink losses, pH, colour and area of Longissimus muscle, pelvic limb, or bone characteristics. Suckling management system significantly affected ADG, milk intake, dressing percentage, and percentages of intestine, stomach, offal, kidney fat, shoulder, lean and fat, and there were differences in total collagen, and hydroxylysylpyridinoline crosslink concentrations. In addition, different IMC maturity among the muscles was apparent.     

Comparison of meat quality between eland (Taurotragus oryx) and cattle (Bos taurus) raised under similar conditions

Physical, chemical and sensory characteristics of meat were compared between non-domestic eland (Taurotragus oryx) bulls (n = 6) and domestic Fleckvieh (Bos taurus) bulls (n = 6) which were finished under controlled conditions of feeding and management. Musculus longissimus lumborum from eland were darker and less yellow in colour, with a higher pH₂₄ and lower contents of intramuscular fat and total collagen, compared to cattle. Contents (mg/100 g muscle tissue) and proportions (g/100 g of FA determined) of SFA and MUFA were higher (P < 0.01) in cattle. Although the proportion of total PUFA were higher (P < 0.001) in eland, contents of PUFA were similar between species. Meat from cattle was consistently scored higher (P < 0.05) for sensory texture characteristics, juiciness, flavour, and overall acceptance. We concluded that bulls of eland provided low-fat meat with a beneficial fatty acid composition from a human nutrition perspective, but with lower sensory scores, compared to bull beef.     

On-line application of visible and near infrared reflectance spectroscopy to predict chemical–physical and sensory characteristics of beef quality

The aim of this study was to assess the on-line implementation of visible and near infrared reflectance (Vis-NIR) spectroscopy as an early predictor of beef quality traits, by direct application of a fibre-optic probe to the muscle immediately after exposing the meat surface in the abattoir. Samples from M.longissimus thoracis from 194 heifers and steers were scanned at quartering 48 h postmortem over the Vis-NIR spectral range from 350 to 1800 nm. Thereafter, samples from M.longissimus thoraciset lumborum were analysed for colour (L^∗, a^∗, b^∗; 48 h postmortem), cooking loss (14 days postmortem), instrumental texture (Volodkevitch, 10 days aged meat; slice shear force, 3 and 14 days aged meat) and sensory characteristics. Vis-NIR calibrations, tested by cross-validation, showed high predictability for L^∗, a^∗ and b^∗ (R² = 0.86, 0.86 and 0.91; SE_CV = 0.96, 0.95 and 0.69, respectively). The accuracy of Vis-NIR to estimate cooking loss and instrumental texture ranged from R² = 0.31 to 0.54, suggesting relatively low prediction ability. Sensory characteristics assessed on 14 days aged meat samples showed R² in the range from 0.21 (juiciness) to 0.59 (flavour). Considering the subjective assessment of sensory characteristics the correlations of Vis-NIR measurements and several meat quality traits in the range from 0.46 to 0.95 support the use of on-line Vis-NIR in the abattoir. Improvement of predictability was achieved if only extreme classes of meat characteristics have to be predicted by Vis-NIR spectroscopy.