Bilberry pomace in growing rabbit diets: effects on quality traits of hind leg meat

Higher Oxygen Content Affects Rabbit Meat's Quality and Fatty Acid Profile in a Modified Atmosphere

After 7 days of storage, the quality of the meat packed in both systems (MAP and VAC) was satisfactory; however, after 14 and 21 days, there was a noticeable decline in quality, as evidenced by changes in the water percentage and color parameters (L∗, a∗, and b∗). However, muscles stored in the MAP1 had the highest tenderness. The results indicated that as the storage time increased (up to 21 days), the share of C14:0 (P < 0.001) and C16:0 (P < 0.001) acids in the fat of the LTL muscles decreased. Only the share of C18:0 (P = 0.001) and C20:1 (P = 0.015) acids was significantly influenced by the packaging method. The highest iodine level was found in MAP1 21 days after packaging (85.68). The ratio of n-6/n-3, PUFA/SFA, AI, and TI indexes, which indicate a higher nutritional quality of fat, varied only with storage time without being affected by the gas mixture (P > 0.05). The H/H level differed significantly with the storage time (P < 0.001), with no effect of the gas mixture (P = 0.133). After the 21-day storage period, the controlled atmosphere led to an increase in the concentration of MUFA and PUFA and a decrease in SFA, according to the study of the fatty acid profile.

Dietary Plukenetia conophora seed alters muscle cholesterol, antioxidant enzymes, and fatty acids in growing rabbits

The influence of dietary inclusion of Plukenetia conophora seed (PCS) on growth, carcass, muscle antioxidant enzymes, fatty acids, meat quality, and sensory attributes of Longissimus thoracis et lumburum muscle in rabbits was examined. Seventy-two, 28 d old male New Zealand rabbits (750 ± 20 g) were randomly allotted to diets containing either no PCS (PCS-0), 2.5% PCS (PCS-2.5) or 5% PCS (PCS-5) for eight weeks, and euthanized. PCS-5 rabbits had higher (P < 0.05) body and carcass weights than the PCS-0 rabbits. Dietary PCS improved feed efficiency in rabbits. Muscle antioxidant enzymes activities and total phenols were higher while muscle cholesterol was lower (P < 0.05) in supplemented meat than the PCS-0 meat. The concentration of C22:6n-3, C20:5n-3 and C18:3n-3 was higher (P < 0.05) in the supplemented meat than the PCS-0 meat. Sensory attributes, carbonyl, and TBARS values and physicochemical properties of meat did not differ among diets. Supplementation of PCS-5 enhances muscle n-3 fatty acids without impairing the sensory properties, and oxidative stability of rabbit meat.

Rabbit meat trade of major countries: regional pattern and driving forces

In in the last 60 or so years, the global rabbit industry has been growing steadily. This paper studies the global rabbit meat trade by focusing on trade growth and regional pattern. First, rabbit meat productionand regional structure are introduced, as the basis of trade. Then, the global rabbit meat trade is studied in detail, including trade growth, regional structural changes, comparative advantages and competitiveness of major countries. Finally, a gravity model is built to test major factors affecting the rabbit meat trade andexplore the driving forces behind the trade. The data come from different channels, including the Food and Agriculture Organization of the United Nations, World Bank, the World Trade Organization and related government statistics. The results show that: (1) Over the past 60 yr, the global rabbit industry has achieved great progress. In the first half of the period, rabbit meat was mainly produced in Europe; then, rabbit meat production in Asia increased steadily and rapidly in the second half period, while European production decreased continuously. (2) The rabbit meat trade had been increasing for about 20 yr from 1961 to 1979, after which it fluctuated for another 20 yr. However, since 2001 it has been stable around an average level of 37 thousand tonnes, with only minor fluctuation. The trade pattern is currently from Asia (mainly China) and South America (mainly Argentina) to European countries. In 2018, the top 5 export destinations were Germany, Belgium, Italy, Portugal and France (3). Hungary and Argentina have been two strong competitorsin the last two decades, while Spain and Belgium are two new and promising countries in the rabbit meat trade. Now China no longer has comparative advantages in the rabbit meat trade (4). The gravity model results show that rabbit meat trade is mainly driven by demand. Countries with a high Gross Domestic Product tend to increase their imports more, but decrease their exports. Countries with higher populations export more rabbit meat but import less. Common language and contiguity of two countries have significant impacts on rabbit meat trade. Based on the above results, some suggestions and policy implications are provided. Rabbit farmers or processing companies should pay more attention to domestic consumers or neighbouring countries to survey potential markets; traders should explore more markets in order to reduce the degree of trade concentration and lower risks. Governments should popularise the nutritional knowledge of rabbit meat to encourage people (especially young people) to consume more healthy rabbit meat instead of pork, with a view to reducing obesity or other heart diseases, etc.

Effect of a Diet Supplemented with Nettle (Urtica dioica L.) or Fenugreek (Trigonella foenum-graecum L.) on the Post-Slaughter Traits and Meat Quality Parameters of Termond White Rabbits

Simple Summary

Herbs can be a perfect supplement in the animal diet. In addition, they improve the functioning of the immune system, regulate the appetite and feed intake of animals, regulate the functioning of the digestive system, stimulate the metabolism of the body as well as quality parameters of meat. In the literature regarding herbal supplements to rabbit fodder, there is not much information on the use of nettle or fenugreek in their nutrition. Both of these herbs are valuable sources of vitamins and minerals. They regulate the digestive system and stimulate appetite. They have a positive impact on the functioning of the immune system and they exhibit antibacterial activity. Nettle improves biochemical, haematological, and immunological parameters. Numerous studies have shown that fenugreek can also have anti-inflammatory, analgesic, and antipyretic properties. The purpose of the study was to analyse the effect of nettle (Urtica dioica L.) leaves and fenugreek (Trigonella foenum-graecum L.) seeds as additives to fodder in order to improve post-slaughter traits and quality parameters Termond White of rabbit meat. Rabbits fed with pellets with the addition of nettle were characterized by a higher slaughter weight, higher weight of hot and cold carcasses, as well as a higher weight of the fore, middle and hind part of the carcass compared to the other two groups. The carcasses of animals fed with fenugreek and nettle had a higher percentage of the fore and hind parts compared to the carcasses of the animals from the control group. For most colour measurement traits, the differences depending on the feeding regime were significant. Summing up, it can be stated that feeding rabbits with herbal supplements, such as nettle or fenugreek, has no negative impact on technological parameters of the meat or the microstructure of the muscles. On the contrary, in the case of nettle, one can speak of a beneficial effect of this herbal supplement on the post-slaughter traits and microstructure of the muscles, as evidenced by the greater share of type I muscle fibres in the composition of muscles, e.g., longissimus lumborum, indicating a more oxidative nature of these muscles, which in turn may translate into the quality of rabbit meat.

Abstract

The purpose of the study was to analyse the effect of nettle (Urtica dioica L.) leaves and fenugreek (Trigonella foenum-graecum L.) seeds as additives to fodder in order to improve post-slaughter traits and quality parameters of Termond White rabbit meat (n = 60; 30♂, 30♀). Three experimental groups were created. The control group (n = 20; 10♂ and 10♀) was fed ad libitum feed containing corn, bran, wheat, dried alfalfa, soybean meal, sunflower meal, dicalcium phosphate, calcium carbonate and vitamin-mineral premix. The animals from the first experimental group (n = 20; 10♂ and 10♀) were fed a complete mixture added with 1% of nettle (Urtica dioica L.) leaves. Rabbits from the second group (n = 20; 10♂ and 10♀) were fed with a complete mixture added with 1% of fenugreek (Trigonella foenum-graecum L.) seeds. Rabbits fed with pellets with the addition of nettle were characterized by a higher slaughter weight, higher weight of hot and cold carcasses, lungs, kidneys and head as well as a higher weight of the fore, middle and hind part of the carcass compared to the other two groups. The carcasses of animals fed with fenugreek and nettle had a higher percentage of the fore and hind parts compared to the carcasses of the animals from the control group. The female carcasses were characterized by a significantly higher percentage of the middle part compared to the male carcasses. For most colour measurement traits, the differences depending on the feeding regime were significant. The effect of gender on meat colour was non significant. The effect of feeding regime and of gender on texture traits such as shear force, hardness, springiness, cohesiveness and chewiness were non significant. Feeding had no effect on muscle fibre diameter, but it affected the muscle fibre type I percentage. Thus, the group fed with pellets containing nettle leaves had higher percentage of type I muscle fibres than the control group. The effect of gender on muscle fibre traits was non significant.

Effect of Thymol Addition and Withdrawal on Some Blood Parameters, Antioxidative Defence System and Fatty Acid Profile in Rabbit Muscle

Simple Summary

So far, the study of the bioactivity of thymol, a major constituent of Thymus vulgaris L., in the animal organism has received little attention. Our study could give us answers to questions about whether thymol accumulates in the rabbit organism after its sustained administration and if it is also able to exhibit its beneficial properties for a longer period. Thymol in powder form at the concentration 250-mg/kg feed was added to the rabbit diet for 21 days and withdrawn for the next seven days. We confirmed that thymol was sufficiently absorbed from the gastrointestinal tract and was able to express its biological activity not only during application but, also, after withdrawal. Further studies are needed to clarify the biotransformation and bioavailability of thymol in the rabbit organism with respect to the specific features of rabbit digestion.

Abstract

Thymol concentrations in rabbit plasma, intestinal wall (IW) and faeces were detected, and the effects of thymol application and withdrawal on biochemical, antioxidant parameters and fatty acids (FA) in blood (B) and muscle (M) were studied. Forty-eight rabbits were divided into two experimental groups (control, C and with thymol 250-mg/kg feed, T). Thymol was administered for 21 days (TA) and withdrawn for seven days (TW). Thymol in plasma correlated with that in the IW (Spearman′s correlation coefficient (r_s) = −1.000, p = 0.0167, TA) and was detected in faeces (TA and TW). In TA alkaline phosphatase (p = 0.0183), cholesterol (p = 0.0228), malondialdehyde (p = 0.003), glutathione peroxidase (p = 0.0177) in B and lactate dehydrogenase (M, p = 0.0411) decreased; monounsaturated FA (p = 0.0104) and α-linolenic acid (p = 0.0227) in M increased. In TW urea (p = 0.0079), docosapentaenoic acid (p = 0.0069) in M increased; linoleic acid (p = 0.0070), ∑ n−6 (p = 0.0007) in M and triglycerides decreased (B, p = 0.0317). In TA and TW, the total protein (p = 0.0025 and 0.0079), creatinine (B; p = 0.0357 and 0.0159) and oleic acid (M; p = 0.0104 and 0.0006) increased. Thymol was efficiently absorbed from the intestine and demonstrated its biological activity in blood and the muscles.

Bilberry pomace in rabbit nutrition: effects on growth performance, apparent digestibility, caecal traits, bacterial community and antioxidant status

Agricultural by-products could be used as alternative raw materials in rabbit nutrition as they have been found to be highly nutritious and low cost feeding sources. The aim of this study was to estimate the nutritive value and potential use of bilberry pomace (BP) for growing rabbits. A total of 144 Grimaud rabbits (35 days old) were allotted to four groups and fed with a diet containing increasing level of BP: BP0 (basal diet), BP5, BP10 and BP15 containing 0, 50, 100 and 150 g/kg respectively. Growth trial lasted 48 days; apparent digestibility was evaluated, starting at 46 days of age, over 4 consecutive days. The nutritive value of BP was measured using the mean digestibility of the experimental diets. At 83 days of age, rabbits were slaughtered: blood, and liver and kidney samples were collected in order to determine the blood parameters and the antioxidant enzyme activities of the tissues. Moreover, caecal content was sampled and gut microbiota assessed by means of amplicon-based high-throughput 16S rRNA sequencing and PCR-denaturing gradient gel electrophoresis. The digestible protein was estimated to 104 g/kg of DM while digestible energy to 9.44 MJ/kg DM for incorporation rate up to 150 g/kg. During the finishing period, average daily feed intake and feed conversion ratio showed linear response to BP increase (P=0.008 and &lt;0.001, respectively). During all the period, both parameters decreased linearly and quadratically with increasing BP inclusion levels (P&lt;0.001) up to 100 g/kg of BP. A significant effect of the antioxidant status was found in the kidneys and liver (P&lt;0.05) where the glutathione peroxidase activity increased as the BP increased. As far as gut microbiota is concerned, BP increased the relative abundance of the Clostridium, Oscillospira, Ruminococcus and Ruminococcaceae species which were clearly associated with the BP inclusion level. In conclusion, BP showed a potential use as an alternative protein and fibre sources for growing rabbits.