Effect of dietary supplementation of Spirulina (Arthrospira platensis) and Thyme (Thymus vulgaris) on growth performance, apparent digestibility and health status of companion dwarf rabbits

The effects of herbal plant extract on the growth performance, blood parameters, nutrient digestibility and carcase quality of rabbits: A meta-analysis

A meta-analysis was conducted to determine the effects of herbal plant extracts on the growth performance, blood parameters, nutrient digestibility and carcase quality of farmed rabbits. A dataset was created from 33 in vivo studies comprising 121 experimental units. Statistical meta-analysis was performed using a random-effects model and linear-mixed model meta-regression using R software (v. 4.3.0). Our results showed that although supplemental herbs did not affect average daily gain (ADG) and final body weight (BW), they reduced (P < 0.01) feed conversion ratio and mortality and increased the digestibility of dry matter (DM) (P = 0.014) and crude protein (CP) (P = 0.018). The herbal extracts also increased (P = 0.037) blood high-density lipoprotein (HDL) and decreased (P = 0.004) low-density lipoprotein (LDL). Immunoglobulin M (IgM) was elevated (P = 0.009) by herbal plant extract supplementation, although most blood components were unaffected. The inclusion of herbal plant extract up to 300 g/kg increased (P = 0.011) carcase percentage while the weight and percentage of other organs were unaffected. Subgroup meta-analysis further explained the different effect of the type of herbal plant extract. Moringa, olive oil, and pepper were more favourable to increase final BW compared to the other herbs. Interestingly, the majority of herbs showed efficacy in reducing mortality. A majority of the response variables in our meta-analysis showed no dose-response effect except for ADG, mortality, HDL, and LDL which were improved by herbs supplementation. The evidence from the perspective of both meta-analysis and meta-regression shows that the addition of herbs tends to positively affect the parameters for production performance and blood metabolites in farmed rabbits.

Dietary supplementation with n-3 polyunsaturated fatty acids: Effects on reproductive and productive performance and meat quality in rabbit breeding

Rabbit breeding has many critical aspects related to reproduction, production, and animal welfare, which reduce its profitability as well as consumer attractiveness. Dietary supplementation with n-3 polyunsaturated fatty acids (PUFA) seems to be a good nutritional strategy to improve several aspects of rabbit breeding, enhance animal welfare and produce a new functional food considered healthy for human consumption. For this reason, the main available scientific research regarding the physiological effects of n-3 PUFA rich products supplemented to the rabbit diet will be reviewed. In particular, consequences on the reproductive performances of both doe and buck, the productive parameters, and the meat quality will be analysed.

Impacts of algae supplements (Arthrospira & Chlorella) on growth, nutrient variables, intestinal efficacy, and antioxidants in New Zealand white rabbits

An 8-week trial to examine the impacts of Arthrospira platensis and Chlorella vulgaris on the growth, nutrient aspects, intestinal efficacy, and antioxidants of 75 New Zealand white male rabbits (initial body weight = 665.93 ± 15.18 g). Herein the study was designed in one-way ANOVA to compare the effects of the two algae species with two levels of supplementations in the feeds of New Zealand white rabbits. The rabbits were divided into five groups (n = 15/group), where the first group was allocated as the control group (Ctrl) while the second and third groups received A. platensis at 300 or 500 mg/kg diet (Ap300 or Ap500). The fourth and fifth groups fed C. vulgaris at 300 or 500 mg/kg diet (Ch300 or Ch500). The basal diet rabbits exhibited the lowest values of weight, lipase, protease, and the highest feed conversion ratio, which improved noticeably with algae addition, particularly with Ap500, Ch300, and Ch500. All tested groups showed normal intestinal structure. Amylase potency, hematological indicators, and serum biochemistry revealed non-significant variation except for a higher serum total protein and lower total cholesterol in algal groups. The best GPx existed in groups fed algal diets, while favorable SOD and CAT efficiency occurred at the higher level of Arthrospira and both levels of Chlorella. In conclusion, incorporating Arthrospira or Chlorella in the diet of New Zealand white rabbits improved performance, nutrient utilization, intestinal efficacy, and antioxidants. Arthrospira (Ap500) and Chlorella (Ch300 or Ch500) have almost the same beneficial effect on rabbit performance.

Oral Palatability and Owners' Perception of the Effect of Increasing Amounts of Spirulina (Arthrospira platensis) in the Diet of a Cohort of Healthy Dogs and Cats

The nutraceutical supplementation of Spirulina (Arthrospira platensis) in dogs and cats has not yet been investigated. The aim of this study was to evaluate if the dietary supplementation of increasing amounts of Spirulina for 6 weeks is palatable to pets and to assess the owner's perception of such supplementation. The owners of the 60 dogs and 30 cats that participated in this study were instructed to daily provide Spirulina tablets starting with a daily amount of 0.4 g, 0.8 g, and 1.2 g for cats as well as small dogs, medium dogs, and large dogs, respectively, and allowing a dose escalation of 2× and 3× every 2 weeks. The daily amount (g/kg BW) of Spirulina ranged from 0.08 to 0.25 for cats, from 0.06 to 0.19 for small-sized dogs, from 0.05 to 0.15 for medium-sized dogs, and from 0.04 to 0.12 for large-sized dogs. Each owner completed a questionnaire at the time of recruitment and the end of each 2-week period. No significant effect on the fecal score, defecation frequency, vomiting, scratching, lacrimation, general health status, and behavioral attitudes was detected by the owners' reported evaluations. Most animals accepted Spirulina tablets either administrated alone or mixed with food in the bowl. Daily supplementation of Spirulina for 6 weeks in the amounts provided in this study is therefore palatable and well tolerated by dogs and cats.

Improving productivity in rabbits by using some natural feed additives under hot environmental conditions - A review

Heat stress is a major challenge to animal production in tropical and subtropical climates. Rabbits suffer from heat stress more than farm animals because they have few sweat glands, and their bodies are covered with thick fur. Intensive farming relies on antibiotics as antimicrobials or growth promoters to increase animals' productivity and health. However, the European Union and many countries have banned or restricted the use of antibiotics in animal feed for human health concerns. Several studies have found that replacing antibiotics in rabbit feed with natural plants or feed additives increases productivity and improves immune capacity, especially under heat stress conditions. Growth performance, immune response, gut microflora, and carcass yield may be increased in rabbits fed a diet supplemented with some natural plants and/or propolis. In this review article, we discuss and summarize the effects of some herbs and plant extracts as alternative feed additives on rabbit productivity, especially for those raised under hot ambient temperatures.

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.

Physiological Performance of Rabbits Administered Buffalo Milk Yogurts Enriched with Whey Protein Concentrate, Calcium Caseinate or Spirulina platensis

The present study examines the impacts of supplementing yogurt with 1% whey protein concentrate (WPC), Ca-caseinate (Ca-CN) and Spirulina platensis on the physiological performance of V-line rabbits receiving diets containing yogurt (at a dose of 5 g/kg body weight/day) and the different meat quality aspects. The results show that fat content was highest (p < 0.05) in yogurt fortified with Spirulina powder, but protein (%) was highest in yogurt enriched with WPC. Yogurt containing Spirulina powder showed a significant (p < 0.05) increase in total antioxidant activity. The final live body weight for G1 was higher than the other groups. However, additives affected the saddle, hind legs, liver and neck percentages significantly (p < 0.05). There were not significant differences for all groups in the forelegs, lung and heart percentages. LDL-cholesterol, total protein, globulin, albumin, creatinine and immunoglobulin M values were lowest (p < 0.05) in the WPC group. Significant improvements appeared in the small intestinal wall, microbiology, growth performance, serum biochemistry, organ histology and meat quality of the group receiving enriched yogurt. Yogurts enriched with WPC, Ca-CN and Spirulina platensis can be used as functional foods.

Thymol in fattening rabbit diet, its bioavailability and effects on intestinal morphology, microbiota from caecal content and immunity

To our knowledge, no study has been carried out to evaluate the effects of thymol sustained administration on gut health and immune response in terms of its bioavailability in the rabbit organism. A total of 48 rabbits were randomly divided at 35 days of age into two dietary treatment groups (C/control or T/thymol at 0.025% addition). Thymol was added for 21 days and then withdrawn for 7 days. Thymol content in faeces (p < 0.001) and caecal content (p < 0.05) was significantly higher than in plasma during the thymol addition and withdrawal (2442 ± 451.4, 881.9 ± 231.3 ng/g DM and 46.2 ± 28.4 ng/ml, respectively; 149.5 ± 40.54, 45.76 ± 12.44 ng/g DM and 2.73 ± 0.45 ng/ml, respectively). Increasing of villi height to crypt depth ratio in small intestinal wall (p < 0.01), phagocytic activity in blood (p < 0.0001) and lactic acid bacteria in caecal appendix (p < 0.01) and faeces (p < 0.05) was still presented after withdrawn of thymol. The thymol at this concentration demonstrated its biological properties and was able to positively affect gut health and immune response of rabbits.

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.

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.

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.

Ameliorative effects of oral ginger and/or thyme aqueous extracts on productive and reproductive performance of V-line male rabbits

The objective of this study was to determine the impact of ginger and/or thyme aqueous extracts administration on the growth rate, caecum activity, reproductive performance and semen quality of rabbits. A total of 24 V-line male rabbits at the age of 12 weeks were divided randomly into four equal groups (6/each) until 24 weeks of age. Treatments were as follows: drinking fresh water and served as control (G1); drinking water supplemented with 100 mg/kg b. wt. of ginger aqueous extract (G2); drinking water supplemented with 50 mg/kg b. wt. of thyme aqueous extract (G3); drinking water supplemented with 100 mg/kg b. wt. of ginger aqueous extract plus 50 mg/kg b. wt. of thyme aqueous extract (G4). Administration of aqueous thyme extract with 50 mg/kg b. wt. improved (p < 0.001) feed intake and growth performance compared to control. The highest average daily gain (p < 0.001) was found for G3 rabbits followed by G4, G2 and G1 respectively. While the most efficient feed conversion ratio was found in G4. Group 3 and group 4 had significant (p < 0.05) positive effect on caecum pH, ammonia and TVFAs concentration. Data indicated that treated groups had hastened the age with heavier body weight, larger testicular size and higher testosterone level. Also, most semen characteristics (volume, progressive motility, sperm concentration and normal spermatozoa) were higher in treated groups compared with the control group. Furthermore, gathering of the spermatozoa in the lumen of the seminiferous tubules, expanded epithelial cells stature of the epididymis with stuffed lumens with sperms in treated groups. In conclusion, aqueous extracts of ginger and/or thyme can be used as a growth promoter for improving reproductive performance of V-line male rabbits.

Ca2+-Calcineurin-NFAT pathway mediates the effect of thymol on oxidative metabolism and fiber-type switch in skeletal muscle

Thymol is a major component of thyme, and it has been reported that thymol administration reduces body weight, plasma insulin and blood glucose in type-2 diabetes.

Dietary supplementation of Digestarom® herbal formulation: effect on apparent digestibility, faecal and caecal microbial counts and live performance of growing rabbits

<p>The experiment aimed to study the effect of Digestarom® dietary inclusion (herbal formulation containing a mixture of essential oils, herbs, spices and extracts) on apparent digestibility and digestive ecosystem of growing rabbits, as well as the effects of its supplementation before and after weaning on growth performance. At kindling, rabbit does and litters were divided into 2 dietary groups (51 does/group) and fed either a control diet (C) or a diet supplemented with 300 mg Digestarom®/kg diet (D) until weaning, which occurred at 35 d (before weaning supplementation). Each group was further divided into 3 dietary groups: CC received the control diet and DD received the D diet from 5 to 12 wk of age, and DC were fed with D (from 5 to 8 wk of age) and C diets (from 8 to 12 wk of age) (after weaning supplementation; 54 kits/group). An in vivo digestibility trial and a faecal microbial count were carried out on growing rabbits that received only the C or D diets during the trial. The C group showed higher DM intake than D group (215 vs. 196 g/d; P&lt;0.05). The faecal digestibility of ether extract (75.9 vs. 59.8%; P&lt;0.001), cellulose (25.9 vs. 20.6%; P&lt;0.05) and gross energy (51.8 vs. 49.1%; P&lt;0.05) was higher for C than for D group, whereas that of starch (98.9 vs. 98.8%; P&lt;0.001) and the digestible protein to digestible energy ratio (13.9 vs. 13.2 g digestible protein/MJ digestible energy; P&lt;0.01) was the highest for rabbits fed D diet. Stomach and caecal pH, caecal and faecal microbial counts were independent of the dietary treatment. The only exception was the stomach pH in 8 wk-old rabbits, which had the lowest value in C rabbits (P&lt;0.05). The D supplementation before weaning improved feed conversion ratio throughout the growing phase (4.3 vs. 4.4 for D and C, respectively; P&lt;0.05), whereas significant differences in daily weight gain, feed conversion ratio and mortality were observed only in the first period after weaning. Based on the results obtained, dietary supplementation with Digestarom® does not seem to confirm the positive results previously reported for growing rabbits.</p>

Dietary Spirulina (Arthrospira platensis) and Thyme (Thymus vulgaris) supplementation to growing rabbits: effects on raw and cooked meat quality, nutrient true retention and oxidative stability

The study evaluated the effect of Spirulina and Thyme dietary supplementation on rabbit meat quality, nutrient true retention and protection against oxidative stress. Rabbits in the control group (C-C) received a non-supplemented pellet throughout the experiment (5-11weeks of age). In the other groups, the pellet contained 5% Spirulina (S), 3% Thyme (T), or both (ST) for either the entire (groups S-S, T-T, ST-ST) or only the final part of the growing period (8-11weeks: groups C-S, C-T, C-ST). Spirulina supplementation increased the γ-linolenic acid content of rabbit meat, whereas Thyme improved the oxidative stability of raw and freeze-dried meat.