Effects of feeding bergamot pulp and olive leaves on performance and meat quality in Apulo-Calabrese pigs.

To determine the effects of dietary inclusion of bergamot pulp and olive leaves on pork quality, thirty-six barrows (Apulo-Calabrese; 112.5 ± 7.40 kg initial bodyweight) were randomly assigned to four experimental treatments and fed for 100 days a control diet (control group) or a diet similar to the control diet in which part of the cereals were replaced with 20 % (DM on the diet fed) of ensiled bergamot pulp (dry matter on the diet fed, EBP group) or olive leaves (OLL group) or a 1:1 mixture of both by-products (BPOL group). In the present study, the dietary administration of by-products did not influence the accumulation of IMF (P > 0.05) in meat. As for individual fatty acids, no differences were observed among groups. However, the dietary supplementation of bergamot pulp tended to increase (P = 0.073) the level of α-linolenic acid in meat. In raw and cooked meat TBARS values were higher (P < 0.001) in the Control group than in EBP, OLL and BPOL groups. The integration of 20 % of bergamot pulp and/or olive leaves by-products increased the levels of tocopherol and phenolic compounds in the diets, positively influencing the shelf life of meat. No effect of diet was observed on animal performance. The results of present study indicated mainly that partial replacement of cereals with 20 % DM on the diet fed of ensiled bergamot pulp and olive leaves, either alone or in combination, in the pig's diet led to greater oxidative stability of the meat.

Effect of high levels of almond hulls supplementation on performance and meat oxidative stability in lambs.

The main objective of this study was to evaluate if high dietary levels of almond hulls could influence performance and meat oxidative stability in lambs. Twenty lambs, at an average body weight of 28.8 ± 0.30 (SD) kg, were divided into two experimental groups and fed ad libitum for 40 days either with a control diet (cereal-based concentrate, control group) or with a similar diet in which part of the cereals was replaced with 40% of almond hulls on a dry matter basis (AH40 group). Dietary AH did not affect dry matter intake but reduced final body weight, average daily gain, feed conversion ratio or carcass weight. In meat, TBARS values were lower (P < 0.001) in the AH40 group than in control group. The partial replacement of cereals with 40% almond hulls in the diet negatively affecting the growth parameters of the animals but can improve meat shelf-life by reducing lipid oxidation.

Effect of Dietary Ensiled Olive Cake Supplementation on Performance and Meat Quality of Apulo-Calabrese Pigs.

The aim of this study was to evaluate the inclusion of different amounts of ensiled olive cake, a major pollutant from olive oil production, in the fattening diets of 30 Apulo-Calabrese pigs as a strategy to partially substitute the traditional cereal-based diet and improve animal performance and meat fatty acid composition. The animals, during a fattening period of 120 days, were fed with three dietary treatments containing increasing levels of ensiled olive cake: 0% (C), 20% (OC20) and 40% (OC40) on dry matter. No effect of the dietary treatment was found on the animal performance and proximate meat analysis results. The inclusion of ensiled olive cake in the diet led to differences in the fatty acid (FA) profile of intramuscular fat, with a higher proportion of monounsaturated fatty acid (MUFA; p < 0.001) and oleic acid (C8:1n-9, p < 0.001) and a lower concentration of polyunsaturated (PUFA, p < 0.001) and linoleic acid (C18:2n-6, p < 0.001). In conclusion, the supplementation of ensiled olive cake at up to 40% in the diets of fattening pigs could represent a useful strategy in Mediterranean areas to naturally improve the nutritional value of meat and valorise a by-product of the olive industry, reducing its environmental impact and promoting the exploitation of this local feed resource according to the principles of the circular economy.

Feeding hazelnut skin to lambs delays lipid oxidation in meat.

This study aimed to investigate the effect of dietary hazelnut skin (HNS), a by-product of confectionery industry, on the oxidative stability of lamb meat. Twenty-two finishing lambs were randomly assigned to 2 groups and fed ad libitum for 56 days on different concentrate-based diets: one control and one experimental, in which 150 g/kg of corn was replaced by HNS. After slaughter, the fat-soluble vitamins content and hydrophilic antioxidant capacity were assessed in fresh meat, as well as color, lipid and protein stability over 7 days of shelf-life trial. Dietary HNS increased (P < 0.001) the tocopherols content of meat and reduced (P < 0.001) lipid oxidation during 7 days of refrigerated storage. Meat from lambs fed HNS showed different (P < 0.05) instrumental color parameters. No diet effect (P > 0.05) was observed on the development of metmyoglobin, hydroperoxides, thiol groups, and carbonyl groups. Feeding HNS to lambs improves the oxidative stability of raw meat by delaying lipid oxidation thanks to the antioxidant molecules (tocopherols and phenolic compounds) contained in this by-product.

Effect of dietary pomegranate by-product on lamb flavour.

This study evaluated the effect of the dietary inclusion of whole pomegranate by-product (WPB) on lamb flavour. Seventeen Comisana male lambs (body weight 14.82 kg ± 2 kg) were assigned to 2 treatments. During 36-day feeding trial, the control group (n = 8) received a conventional concentrate diet; the other group (n = 9) received a concentrate diet containing 200 g/kg (dry matter) of WPB, replacing part of barley and corn. After slaughter, fatty acids were determined in raw meat, while volatile organic compounds, SMart nose, and sensory traits were analysed in cooked meat. The concentrations of total polyunsaturated fatty acids, vaccenic and rumenic acid were higher in WPB meat. Most of volatile compounds that arise from lipid degradation (i.e., aldehydes, alcohols, ketones, and hydrocarbons) were found at higher concentrations in the WPB meat than in the control, except for 2-pentanone that was greater in control meat. Although SMart nose clearly discriminated between dietary treatments, consumer panel did not detect differences in meat flavour.

Influence of almond hulls in lamb diets on animal performance and meat quality.

Almond hulls (AH) were fed to lambs to study effects on performance and meat quality. Thirty Sarda lambs were allotted to three experimental groups and fed for 40 days either a cereal-based concentrate diet (control) or diets in which cereals were replaced with 15% (AH15) or 30% (AH30) almond hulls on a DM basis. Diets did not affect final body weight, dry matter intake, average daily gain, feed conversion ratio or carcass weight. Replacing part of the cereal mix (i.e., barley and maize) with AH did not affect meat fatty acid profiles. After 5 and 7 days of refrigerated storage respectively for cooked and raw meat, AH15 and AH30 treatments reduced meat lipid oxidation (P < 0.001). Our results suggest feeding almond hulls up to 30% in fattening lamb diets can improve meat oxidative stability without compromising growth performance.

Influence of Dietary Inclusion of Exhausted Bergamot By-Product in Pigs on Animal Performance, Fatty Acid Profile and Oxidative Stability of Meat and Meat Products.

An investigation was carried out on the effect in pig diet of supplementation with exhausted bergamot by-product, stemming from pharmaceutical industry after extraction of phenolic compounds, on growth performance and on the quality of meat and meat products. Twenty pigs were assigned to two dietary treatments and fed a conventional concentrate (control) or a concentrate including exhausted bergamot by-product at the level of 15% on a DM basis (EB). No significant differences between dietary treatments were found for final weight (p = 0.243), carcass weight (p = 0.679), dry matter intake (p = 0.321). In EB pork, the proportion of docosapentaenoic acid was significantly increased (p < 0.05); it tended to have a greater proportion of n-3 PUFA (p = 0.09), and the n-6/n-3 PUFA ratio was lower in EB treatment (p = 0.01). In salami from EB pigs fed, the proportion of α-linolenic acid and the total n-3 PUFA were higher than in the control group (p < 0.001). In salami, the TBARS value was lower after 5 days of storage (p < 0.001) in the EB group. Therefore, the present results suggest that the inclusion of exhausted bergamot by-product in pig diet resulted in a qualitative improvement of meat and meat products.

Effect of different levels of organic zinc supplementation on pork quality.

This study investigated the effect of two supplementation levels of zinc glycinate (ZnGly) on performance, carcass characteristics, and meat quality of growing-finishing pigs. Thirty pigs (bodyweight: 61 ± 4.0 kg) were assigned to three treatments and fed ad libitum for 56 days a diet supplemented with 0 (control), 45 (Zn45), or 100 mg/kg (Zn100) of ZnGly. The highest ZnGly supplementation lowered the average daily gain (P = 0.031); while, cold carcass weight did not differ between treatments. Both ZnGly levels reduced carcass chill loss (P < 0.001). Micromineral content, color stability, and fatty acid profile of meat were not altered by ZnGly. Superoxide dismutase activity was lowered by Zn45 compared to control (P = 0.007); while, catalase activity was enhanced by Zn100 (P = 0.003). Although ZnGly supplementation did not influence lipid oxidation in raw meat and in meat homogenates incubated with pro-oxidant catalysts, Zn45 limited lipid oxidation in cooked meat (P = 0.037). Our results demonstrated that supplementing pigs with 45 mg/kg of ZnGly could improve the oxidative stability of pork subjected to strong pro-oxidant conditions, but this effect needs to be further elucidated.

Effect of feeding pigs with bergamot by-product on fatty acid composition and oxidative stability of meat and salami.

This work investigated the effects of feeding ensiled bergamot pulp to pigs on meat and salami quality. Eighteen pigs were assigned to two experimental treatments and fed a cereal-based concentrate diet (control) or the same diet in which ensiled bergamot pulp replaced 15% dry matter of the diet fed (BP). The BP treatment increased α-linolenic acid (+250%; P < 0.05), docosapentaenoic acid (+62%; P < 0.05), docosahexaenoic acid (+43%; P < 0.05) and consequently n-3 PUFA (+15%; P < 0.01) in meat. In salami, the content of α-linolenic acid, total PUFA and n-3 PUFA increased (+320%, +25% and + 258%, respectively) by feeding the BP diet (P < 0.001). The inclusion of bergamot pulp in the diet did not alter the oxidative stability in raw and cooked meat and colour descriptors. In salami, TBARS values were lower after 5 days of storage (P < 0.001) in BP group (1.54 vs 2.96). Finally, dietary supplementation with ensiled bergamot pulp to pigs improved the nutritional value of meat and meat products.

Fatty acids and oxidative stability of meat from lambs fed carob-containing diets.

Male Comisana lambs were individually stalled and, for 56 days, were fed concentrates with 60% barley (n = 8 lambs), or concentrates in which barley was partially replaced by 24% or 35% carob pulp (n = 9 lambs in each group). The intramuscular fatty acids were analyzed and the color stability, lipid and protein oxidation were measured in fresh meat overwrapped with polyvinyl chloride film at 0, 3 or 6 days of storage at 4 °C in the dark. Carob pulp increased the concentration of polyunsaturated fatty acids (PUFA) in muscle, including the rumenic acid (P < 0.01), and reduced the saturated fatty acids (P < 0.01) and the n-6/n-3 PUFA ratio (P = 0.01). The meat did not undergo extensive oxidative deterioration and the diet did not affect the oxidative stability parameters. Therefore, carob in lamb diet could increase PUFA in muscle without compromising meat oxidative stability.

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 ß-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.

Effect of morning vs. afternoon grazing on intramuscular fatty acid composition in lamb.

The aim of this study was to assess whether different grazing management affect animal performance and meat fatty acid composition. Thirty-five lambs were divided into three groups: 12 lambs grazed from 9 am to 5 pm (8 h group); 11 lambs grazed from 9 am to 1 pm (4hAM group) and 12 lambs grazed from 1 pm to 5 pm (4hPM group). The trial was conducted over 72 days. The 8 h lambs had greater DMI (P<0.0005) and final body weight (P<0.05) than the 4hPM and 4hAM lambs while carcass weight was not different between the three groups. The meat of the 4hPM lambs contained greater (P<0.05) percentages of polyunsaturated fatty acids, C18:2 cis-9 trans-11 and lower saturated fatty acids and C18:0 than the meat of the 8 h and 4hAM lambs. It is concluded that allowing lambs to graze during the afternoon rather than during 8 h does not compromise the carcass yield and results in a healthier meat fatty acid profile.

The volatile compounds in lamb fat are affected by the time of grazing.

This study was designed to assess whether different grazing managements affect the appearance of organic volatile compounds (VOC) in lamb fat. Forty-two lambs were divided into four groups: 9 lambs were restricted in stall and fed concentrate (S group); 12 lambs grazed from 9 am to 5 pm (8h group); 10 lambs grazed from 9 am to 1 pm (4 hAM group) and 11 lambs grazed from 1 pm to 5 pm (4 hPM group). After 72 days on feed the animals were slaughtered and the perirenal fat subjected to SPME-GC/MS analysis of VOC; the data were analyzed by stepwise discriminant analysis. The 6-methyl-2-heptanone and furanone, 2,5-dimethyl, 4-hydroxy-3(2H) allowed discrimination between the 4 hAM and the 4 hPM animals. These are the first results indicating that the time of the day in which the animals are allowed to graze affects the appearance of VOC in lamb fat.

Δ(9) 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 Δ(9)desaturase (Δ(9)d) protein expression in longissimus dorsi muscle of lamb. Twenty-eight Comisana lambs (age 45days) 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 105days. 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 Δ(9) desaturase protein expression. There was no correlation between Δ(9)d protein expression and total intramuscular fatty acids, CLA and MUFA level. It was suggested that in ruminants, in contrast to monogastric animals, Δ(9)d 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 Δ(9)d 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.