Productive performance and meat quality traits in growing rabbit following the dietary supplementation of Lippia citriodora , Raphanus sativus and Solanum lycopersicum extracts

Effects of Bergamot (Citrus bergamia Risso) By-Product on Growth Performance and Meat Quality of Growing Rabbits

This study aimed to investigate the effects of feeding dried bergamot pulp to rabbits on animal performance and meat quality. Thirty rabbits were assigned to two groups (balanced for body weight, 804.4 ± 2.35 g) and fed individually for 60 days a basal diet (control) or the basal diet in which part of the cereals was replaced with 10% of dried bergamot pulp (DBP). There were no effects of DBP on growth performance, carcass yield, or the crude protein and ether extract composition of meat. The concentrations of α-linolenic acid (C18:3 n-3) and eicosapentaenoic acid (C20:5 n-3) increased in the longissimus thoracis et lumborum muscle (p < 0.01 and p = 0.021, respectively) after integrating dried bergamot pulp into the diet, leading to higher levels of total of ω-3 fatty acids (p < 0.01) compared to the control treatment. The inclusion of dried bergamot pulp improved the oxidative stability in meat (p < 0.001), where TBARS values were lower after 4 and 7 days of refrigerated storage (p < 0.001) in the DBP group than in the control group. Finally, feeding dried bergamot pulp to rabbits improves meat quality without negatively influencing growth performance.

Effects of Rosa roxburghii Tratt seed on the growth performance, meat quality, and sensory evaluation characteristics in growing rabbits

The objective of this study was to observe the effects of Rosa roxburghii Tratt seed (RRTS) on growth performance, meat quality, and sensory characteristic parameters in rabbits. Ninety-six New Zealand White rabbits were allotted to four dietary treatments containing 0 (CON), 120 (LR), 240 (MR), and 360 mg/kg (HR) RRTS. The experimental period lasted for 11 weeks. Thirty-two fattened rabbits were slaughtered, and the Longissimus thoracis et lumborum (LTL) muscle was used for analyses. The feeding of RRTS was significantly (P < 0.05) decreased the feed conversion ratio (FCR). pH45min, pH24h, lightness, redness, drip loss, and percentage of water loss were unaffected (P > 0.05) by dietary treatments, whereas MR and HR treatments resulted in lower (P < 0.05) levels of yellowness and higher (P < 0.05) levels of shear force. LR showed significantly higher (P < 0.05) meat polyphenol compounds and vitamin E relative to the CON. Moreover, compared to the CON, HR treatment showed significantly higher (P < 0.05) vitamin C and glutathione peroxidase, and LR and MR displayed lower (P < 0.05) superoxide anion radicals, and all treatments had higher levels catalase (CAT). C18:2n-6 t, C20:2, C20:3n-6, C20:4n-6, C20:5n-3, C22:5n-3, and C22:6n-3 in LTL meat were higher (P < 0.05) in MR than CON rabbits. Moreover, the LTL muscle sensory evaluation parameters of appearance and fibrousness were improved (P < 0.05). Overall, dietary supplementation with RRTS is a valid strategy for decreasing FCR, and improving meat CAT concentration, C20:5n-3 and C22:5n-3 profiles, and sensory characteristics parameters of rabbits.

Verbascoside-Rich Plant Extracts in Animal Nutrition

In recent years, the search for dietary intervention with natural products able to sustain animal health and decrease environmental impact, has raised the number of studies pertaining to the use of plants' secondary metabolites. In fact, in livestock, there is a clear relationship between the animals' antioxidant status and the onset of some diseases that negatively affect animal welfare, health, and productive performance. An interesting compound that belongs to the secondary metabolites family of plants, named phenylpropanoids, is verbascoside. The genus Verbascum, which includes more than 233 plant species, is the genus in which this compound was first identified, but it has also been found in other plant extracts. Verbascoside exhibits several properties such as antioxidant, anti-inflammatory, chemopreventive, and neuroprotective properties, that have been evaluated mainly in in vitro studies for human health. The present work reviews the literature on the dietary integration of plant extracts containing verbascoside in livestock. The effects of dietary plant extracts containing verbascoside on the productive performance, antioxidant status, blood parameters, and meat quality in several animal species were evaluated. The present data point out that dietary plant extracts containing verbascoside appear to be a favorable dietary intervention to enhance health, antioxidant status, and product quality in livestock.

Dietary supplementation of Allium cepa skin alters intramuscular fat, muscle cholesterol, and fatty acids in rabbits

BACKGROUND

The high polyunsaturated fatty acids content of rabbit meat predisposes it to oxidative deterioration, which often results in reduced product quality and shelf life. This fact highlights the need to improve the antioxidant status of rabbit meat. This study investigated the effects of dietary supplementation of Allium cepa skin (ACS) on growth, carcass, intramuscular fat, muscle fatty acids, cholesterol content, meat quality, antioxidant status, and sensory attributes of hind leg muscle of rabbits. Sixty-three, 28-day-old, male New Zealand rabbits (654 ± 25 g) were randomly allocated into 21 pens of three rabbits. The pens were randomly assigned to one of three dietary treatments - ACS-0: basal diet (BD) only; ACS-25: BD + 25 g kg^-1 ACS; and ACS-50: BD + 50 g kg^-1 ACS - for 56 days and then euthanized.

RESULTS

Dietary ACS did not affect growth performance and retail cuts of rabbits. Muscle cholesterol was lower (P < 0.05) in ACS-supplemented rabbits than in controls. Dietary ACS lowered (P < 0.05) dissectible fat, intramuscular fat content, C14:0, C16:0, C18:0, C18:2n-6, and C20:4n-6 levels and enhanced (P < 0.05) C18:3n-3, C20:5n-3, C22:6n-3, and C22:5n-3 concentration. Dietary ACS increased muscle catalase activity in rabbits. Sensory qualities, malondialdehyde and carbonyl contents, and physicochemical attributes of hind leg muscle of rabbits after chill storage were not influenced by dietary ACS supplementation.

CONCLUSION

Supplementation with 50 g kg^-1 ACS reduced intramuscular fat and cholesterol content and improved muscle n-3 fatty acids without impairing the physicochemical and sensory properties of rabbit meat. © 2021 Society of Chemical Industry.

Effect of Teucrium trifidum powder on some meat quality attributes of chevon under refrigerated storage

We investigated the effect of T. trifidum on the shelf-life and quality of chevon kept for eight days at 4 ± 1 °C in polyethylene pouches. Different powder levels of T. trifidum (0.5 %, 1.0 %, and 2.0 % w/w) and 0.02 % w/w butylated hydroxytoluene (BHT) were used to treat the chevon samples. The T. trifidum and BHT treated chevon was compared to untreated chevon (control). Colour, ferric reducing antioxidant power (FRAP), lactic acid bacteria (LAB) counts, oxidative stability, pH and total viable counts (TVC) were all measured while the samples were in storage. Treatment demonstrated a significant (P < 0.05) influence on pH with chevon preserved with T. trifidum powder (2 %), having a lower pH than the chevon preserved with BHT and the control. The colour of chevon (lightness, redness and yellowness) was shown to differ (P < 0.05) across treatments. The redness (a∗) and yellowness (b∗) reduced as the refrigeration period lengthened (P < 0.05).

In contrast, the lightness (L∗) of chevon intensified as the storage period lengthened (P < 0.05). The TBARS considerably reduced (P < 0.05) in samples subjected to T. trifidum powder and BHT, with respect to the untreated sample. There was an increase in the FRAP activity as the amount of T. trifidum powder (P < 0.05) was increased. The FRAP values were shown to be inversely related to the TBARS values, implying that the addition of T. trifidum powder could slow lipid oxidation. In comparison with the control, T. trifidum powder inhibited bacterial growth during storage as measured by a significant reduction in TVC and LAB counts (P < 0.05). It is concluded that, T. trifidum powder has potent antioxidant and antimicrobial activity in refrigerated ground chevon thus can be potentially used to preserve the quality of refrigerator stored ground chevon.

Effect of the type of packaging on the shelf life of ground rabbit meat

Rabbit meat consumption has increased worldwide due to its health benefits in humans but few studies addressed the stability of this food matrix. The effect of two types of packaging (vacuum, VP; and polystyrene tray overwrap with PVC/polyvinyl plastic film, PT) was evaluated on the microbial stability (psychrotrophic; PSY, lactic acid bacteria; LAB, initial coliforms counts) and physicochemical (pH, thiobarbituric acid reactive substances (TBARS), total volatile basic Nitrogen (TBV-N), color and drip loss) changes of ground rabbit meat during its storage at 4 ± 1 °C. VP packaging delayed PSY growth, lipid oxidation, protein degradation and undesirable color changes compared to PT samples. Shelf life of ground rabbit meat in vacuum condition could be around 10 days of storage, while PT samples presented a shorter shelf life of around 5 days. However, sensory studies must be performed in order to assure the exact shelf life of the final product.

Effects of Long-Term Supplementation with Brown Seaweeds and Polyphenols in Rabbit on Meat Quality Parameters

The objective of the present study was to evaluate the effects of dam and offspring dietary supplementation with a natural feed additive on the growth performance and meat quality parameters of growing rabbits. The growing rabbits are selected from lactating does receiving a control diet (C) or diets supplemented with 0.3% (SP1) and 0.6% (SP2) of feed additive containing brown seaweeds (Laminaria spp.) and plant extracts. In the postweaning phase, the growing rabbits remained in the treatment group defined by their does and the trial lasted 42 days. The average daily feed intake and feed conversion ratio were improved in the rabbit fed 0.6% of the natural feed additive. The cholesterol content tended to be lower in Longissimus lumborum (LL) muscle and decrease in Semimembranosus (SM) muscle (in SP2 -41.36% than controls). The α tocopherol and retinol content were enhanced in both muscles of rabbit fed the natural mixture (SP1 and SP2 groups). An improvement of sensory attributes of texture was observed in both muscles from rabbit fed natural mixture. In conclusion, long term supplementation of both lactating does and offspring with the high dosage of brown seaweed and plant polyphenols improves growth performance and enhances meat nutritional and sensory parameters.

Effects of dietary levels of brown seaweeds and plant polyphenols on growth and meat quality parameters in growing rabbit

Growth performances, carcass characteristics and meat quality parameters from growing rabbit fed with two levels of dietary brown seaweed (Laminaria spp) and plant polyphenols were investigated. One hundred and forty-four New Zealand White rabbits were allotted into three dietary treatments containing 0 (C), 0.3% (T1), and 0.6% (T2) of brown seaweed and plant polyphenols mixture for 42 days. Growth performances and carcass weight were improved in T1 group. Vitamin A and E content in Longissimus thoracis and lumborum (LTL) and Semimembranosus (SM) muscle were enhanced in the treated groups. In the SM muscle, the oxidative stability was improved in rabbit fed with both dosages of dietary supplement, and the cholesterol content tended to be lower in T1 than in T2 and C groups. The LTL and SM muscle sensory characteristics were improved. In conclusion, dietary integration with a low dosage of brown seaweed and plant polyphenols is a valid strategy for enhance growth performance and produce healthier rabbit meat.

Polyphenolic composition and antioxidant capacity of legume-based swards are affected by light intensity in a Mediterranean agroforestry system

BACKGROUND

In Mediterranean grazed woodlands, microclimate changes induced by trees influence the growth and development of the understory, although very little is known about its polyphenolic composition in relation to light intensity. We investigated the bioactive compounds and antioxidant capacity of different legume-based swards and variations as a result of full sunlight and partial shade. The research was carried out in a cork oak agrosilvopastoral system in Sardinia.

RESULTS

The highest values of (1,1-diphenyl-2-picrylhydrazyl) (DPPH) reached 7 mmol Trolox equivalent antioxidant capacity 100 g^-1 dry weight (DW), total phenolics 67.1 g gallic acid equivalent kg^-1 DW and total flavonoids 7.5 g catechin equivalent kg^-1 DW. Compared to full sunlight, partial shade reduced DPPH values by 29% and 42%, and the total phenolic content by 23% and 53% in 100% legume mixture and semi-natural pasture, respectively. Twelve phenolic compounds were detected: chlorogenic acid in 80% legume mixture (partial shade) and verbascoside in pure sward of bladder clover (full sunlight) were the most abundant.

CONCLUSION

Light intensity significantly affected antioxidant capacity, composition and levels of phenolic compounds. The results of the present study provide new insights into the effects of light intensity on plant secondary metabolites from legume-based swards, highlighting the important functions provided by agroforestry systems. © 2018 Society of Chemical Industry.

Rabbit metabolic response and selected meat quality traits: Evaluation of dietary PLX® 23 and LycoBeads® feed supplement

Effects of dietary supplementation of verbascoside and lycopene, alone and in combination, on some blood parameters, plasma oxidative status and meat quality traits in intensively reared rabbits were investigated. The test lasted 60 days and was conducted on 200 weaned-rabbits, divided into four groups of 50 animals each (5 animals each cage × 10 repetitions). The control group (CON) received a fattening feed without any feed supplements, whereas the experimental groups received the following: the first, an integration in 22 g of PLX^® 23 (Lippia citriodora extract; VB group) per ton of feed; the second, an integration in 100 g of LycoBeads^® (Solanum lycopersicum extract; LIC group) per ton of feed; and the third, an integration of both feed supplements in combination at the same doses (LIC+VB group). The dietary supplementation with Lippia citriodora and Solanum lycopersicum resulted in an improvement of the blood lipid profile, oxidative plasma markers, and hepatic and renal activity of treated growing rabbits. Feed additives also produced meat with a lower content in SFA and an increased PUFA content, and inhibited the lipid oxidation improving the oxidative stability of rabbit meat. The dietary supplementation, even reporting no effects on productive parameters and carcass yield, showed an improvement on several blood parameters, as indicator of animal welfare, and on quality and healthy meat markers.

Comparative evaluation of the quality and fatty acid profile of meat from brown hares and domestic rabbits offered the same diet

Since animal diets have a strong influence on meat quality, a comparative study on farmed brown hares and domestic rabbits offered the same diet was undertaken to assess the physical and chemical properties of their meat. Ten brown hares and ten domestic rabbits were used to characterize the traits of meat from the foreleg, hind leg, and Longissimus lumborum muscles. The study indicated higher protein content in hare meat than in rabbit meat. The meat of hares had a concentration of heme iron that was more than twice as high as that of rabbits. Lower SFA and MUFA content and higher PUFA content contributed to the superior PUFA/SFA ratio in hares. An unfavorable n-6/n-3 ratio but superior atherogenic and thrombogenic indices was observed for hare meat. The higher TBARS of hares indicated a higher susceptibility of hare meat to lipid oxidation. Hare meat was also characterized by a higher water holding capacity and higher color indices (redness and chroma).

Rabbit meat production and processing in China

Rabbit meat has become increasingly popular in China; however, the main available products are still as cut-up parts or whole carcass due to a lack of processing. Currently, rabbit meat products do not fully meet the consumer demand for convenience, thus hindering the further development of the rabbit meat industry. As the biggest rabbit meat producer globally, China has conducted a series of studies on rabbit meat processing and the development of new products. This review presents rabbit breeds, meat importation, exportation, and meat production in China. The development of the rabbit meat industry and research on rabbit meat processing are discussed. The main problems, including a lack of leading enterprises and brand products, insufficient investment and research, and the weakness of fundamental studies on traditional products, are highlighted. Furthermore, current trends of rabbit meat production and processing of being centralized and regionalized, as well as being intelligentized and standardized, are discussed.

Preservative potential of Tinospora cordifolia, a novel natural ingredient for improved lipid oxidative stability and storage quality of chevon sausages

Purpose

The purpose of this study was to assess the preservative potential of Tinospora cordifolia as a novel natural preservative in muscle foods.

Design/methodology/approach

Chevon sausages were used as a model system and were prepared by incorporating different levels of T. cordifolia, namely, T1 (0.25 per cent), T2 (0.50 per cent) and T3 (0.75 per cent), and assessed for lipid oxidative stability and storage quality under refrigerated (4 ± 10°C) conditions.

Findings

Lipid oxidative stability showed a significant improvement as the products incorporated with T. cordifolia exhibited significantly (p = 0.001) lower thiobarbituric acid reacting substances (mg malonaldehyde/kg) in comparison to control. A significant improvement was also observed in the microbial stability as T. cordifolia-incorporated products showed significantly lower values for total plate count (log cfu/g, p = 0.001), psychrophilic count (log cfu/g, p = 0.003), yeast and mould count (log cfu/g, p = 0.02) and free fatty acid (percentage of oleic acid, p = 0.01). Significantly higher scores were observed for various sensory parameters of the treated products during storage.

Originality/value

Tinospora cordifolia successfully improved the lipid oxidative and microbial stability of the model meat product and may be commercially exploited as a novel preservative in muscle foods.