Thyme oil inclusion levels in a rabbit ration: Evaluation of productive performance, carcass criteria and meat quality under hot environmental conditions

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.

Effects of Dietary Acacia nilotica Fruit, Zinc Oxide Nanoparticles and Their Combination on Productive Performance, Zinc Retention, and Blood Biochemistry of Rabbits

This study aims to examine the effects of supplementing male rabbit diets with nanoparticles of zinc oxide (Nano-ZnO) and Acacia nilotica fruit powder (ANFP) on production sustainability under hot climatic conditions. Eighty Californian male rabbits aged 40 days old (average body weight 738.5 ± 11 g) were divided into four treatment groups and administered one of the following diets: control diet, Nano-ZnO (50 mg/kg), ANFP (5 g/kg), or a combination of Nano-ZnO (50 mg/kg) and ANFP (5 g/kg) for a period of 60 days. Each of the 20 rabbits used in a treatment was regarded as a replicate. The results showed that adding Nano-ZnO and ANFP individually or in combination to rabbits' diets improved (p < 0.05) growth performance in comparison to control. In addition, zinc contents in serum or the testis tissues in the Nano-ZnO- and ANFP-treated rabbits were significantly greater (p < 0.05) than those in the control group. In addition, serum levels of creatinine, alanine aminotransferase, and aspartate aminotransferase were decreased (p < 0.05) by supplementation of Nano-ZnO, ANFP, or their combination. Carcass criteria did not differ among the treatments. Overall, the findings of the present study indicate that rabbits fed diets containing Nano-ZnO and ANFP, as well as their combination, showed improvements in growth performance, kidney and liver functions, as well as zinc retention in tissues under hot climatic conditions. The combination of Nano-ZnO and ANFP exhibited the best performance in the rabbits. More research on the synergistic effects of Nano-ZnO and ANFP in the sustainable production of rabbit meat is required.

Ramifications of Heat Stress on Rabbit Production and Role of Nutraceuticals in Alleviating Its Negative Impacts: An Updated Review

Heat stress has become a widespread concern worldwide, which is a major environmental stress that causes substantial economic loss in the rabbit industry. Compared to other agricultural animals, rabbits are more sensitive to heat stress as they have fewer sweat glands and a thicker coat of fur, increasing the heat dissipation complexity. Thus, heat stress hurts rabbits' productivity, meat quality, reproductive performance, antioxidative properties, immune responsiveness, intestinal histomorphology, and microbiome. Nutraceuticals include vitamins, minerals, antioxidants, organic acids, fatty acids, probiotics, prebiotics, synbiotics, enzymes, and medicinal plants due to the possible impacts on maintaining common biological situations, strengthening immune response, and preventing illness, which ultimately led to an increase in productivity. Nutraceuticals have recently attracted a lot of attention to alleviate the adverse impacts of heat stress in rabbit farms. The objective of the current review is to provide acquaintance with the recent findings about the impact of heat stress on rabbit productivity and the advantages of dietary supplementation of nutraceuticals in mitigating it.

Effects of Dietary Bioactive Lipid Compounds of Acacia nilotica Bark on Productive Performance, Antioxidant Status, and Antimicrobial Activities of Growing Rabbits under Hot Climatic Conditions

This study aimed to evaluate the efficacy of dietary Acacia nilotica bark bioactive lipid compounds (ANBBLCs) as novel feed additives on the growth performance, carcass criteria, antioxidants, and antimicrobial activities of growing male rabbits. A total of 100 California male weanling rabbits aged 35 days were divided into four nutritional treatments, each of which contained ANBBLCs at concentrations of 0 (control group), 50, 100, and 150 mg/kg diet (n = 25 per treatment, each replication consisting of one animal). The average body weight of the animals was 613 ± 14 g. The experiments lasted for 56 days. Dietary ANBBLC levels linearly improved (p < 0.05) the body weight, body weight gain, and feed conversion ratio (FCR) of rabbits. Furthermore, with increasing concentrations of ANBBLCs, the total antioxidant capacity of blood and liver tissue was linearly (p < 0.05) enhanced. Lactobacillus increased and Staphylococcus decreased (p < 0.05) in comparison to the control group when ANBBLC levels were added to the diets of rabbits. Rabbit diets supplemented with ANBBLCs increased dressing percentages and decreased abdominal fat. This study shows that ANBBLCs can be used as a feed additive to enhance the growth performance, carcass criteria, antioxidant, and antibacterial properties of growing rabbits.

Productive, physiological and nutritional responses of laying hens fed different dietary levels of turmeric powder

This study aimed to determine the impact of supplementation of turmeric powder on laying performance, egg quality, nutrient digestibility and some blood metabolites in laying hens. A total of one hundred and twenty Bovans Brown laying hens (55 weeks old) were assigned to one of four treatment diets (n = 30) for 12 weeks including turmeric powder at 0, 2.5, 5 or 7.5 g/kg respectively. The results revealed that egg production, egg weight and egg mass were significantly increased (p < 0.05), and the feed conversion ratio was significantly improved (p < 0.012) with increasing levels of turmeric in the laying hen diet. Egg thickness and Haugh unit were linearly increased (p < 0.01) with increasing supplementation levels. Moreover, compared with the control diet, the levels of turmeric powder supplementation significantly improved nutrient digestibility (p < 0.001). Moreover, the serum metabolic profile revealed that serum total cholesterol, aspartate aminotransferase, creatinine and urea concentrations were linearly decreased with increasing turmeric powder supplementation to hen diets. In conclusion, the inclusion of turmeric powder at 2.5, 5 or 7.5 g/kg diet improved egg production, nutrient digestibility, egg quality and serum metabolic profile and may be used as a feed additive in laying hens' nutrition. However, results indicate that the best improvement was observed when 5 g/kg were supplemented.

Pumpkin seed oil-supplemented diets promoted the growth productivity, antioxidative capacity, and immune response in heat-stressed growing rabbits

Heat stress is the most major environmental element contributing to rabbit health problems and reduced production. It is proposed that essential oils be applied to alleviate heat stress-induced oxidative damage in rabbits. The purpose of this feeding trial was to determine the protective impact of pumpkin seed essential oil (PSO)-supplemented diets in reducing the threat of unambient temperature on growing rabbits. Five groups of 5-week-old rabbits were allocated randomly into separated galvanized wire battery. The first group was raised under normal conditions (18 ± 2 °C) and fed a control diet (control group; CNT), whereas the other four groups were exposed to high ambient temperature (38 ± 2 °C) and fed a control diet supplemented with 0 (PSO_0.0), 0.5 (PSO_0.05), 1.0 (PSO_1.0), and 2.0 (PSO_2.0) mL PSO/kg diet. Results indicated that all supplemented groups and the positive control have higher live body weight compared with the heat stress group (PSO_0.0) at 9 weeks of age. Supplementing of PSO resulted in significant improvement in weight gain at 5-9 weeks and 9-13 weeks compared with PSO_0.0 group. The highest feed intake was detected in PSO_0.05 group compared with that in other groups. Both PSO_2.0 and PSO_2.0 groups showed the lowest feed conversion ration compared with other groups. Heat-stressed rabbits given a high dose of PSO (1 to 2 mL) had higher hemoglobin concentrations and lower white blood cell counts throughout the experiment than those given a control diet and subjected to heat stress. All hepatic and renal function parameters improved significantly in the rabbits fed a high dose of PSO as compared to the heat-stressed control group, while protein constituents were significantly higher in experimental groups fed 2 mL PSO compared with other groups. Heat-stressed rabbits administered graded amounts of PSO had the lowest plasma glucose, cortisol, thyroid, and corticosterone concentrations and were noticed to be equivalent to the control group fed unsupplemented diet and reared under normal conditions. The immunohistochemistry analysis demonstrated that rabbit groups reared under heat stress and given 2 mL PSO supplemented diets had negative caspase-3 immunoreactivity surrounding portal tract and normal structure. In conclusion, adding pumpkin seed oil up to 2 mL/kg diet for growing rabbits is indorsed to promote growth as well as antioxidant and immunological status under heat stress conditions.

Effects of Zinc Oxide Nanoparticle Supplementation on Performance, Digestibility, and Blood Biochemistry of Californian Male Rabbits Under Hot Climatic Conditions

This study aims to investigate the effects of nanoparticles of zinc oxide (Nano-ZnO) supplementation on productive performance, nutrient digestibility, mineral retention, and blood biochemistry of Californian male rabbits under hot climatic conditions. A total of 100 Californian male rabbits 90 days of age (BW: 1790 ± 13 g) were randomly assigned to one of five treatment diets: Nano-ZnO at 0, 25, 50, 75, or 100 mg/kg, respectively, for 90 days. The rabbits were raised in an open house system (average ambient temperature of 39 °C, relative humidity of 30-35%, and temperature-humidity index of 33.6-34.0). Each treatment had 20 rabbits, and each rabbit was considered as a replicate. During the entire study period, there were no significant differences (P > 0.05) in BW, BW gain, feed intake, or feed conversion ratio between the treatment groups. Nano-ZnO supplementation at 25, 50, 75, and 100 mg/kg enhanced the digestibility coefficient of crude protein (CP) and ether extract (EE) considerably (quadratically, P < 0.05) when compared to the control group. In addition, when Nano-ZnO was supplemented at 25, 50, 75, and 100 mg/kg, serum levels of creatinine, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were considerably lower than the non-supplemented control group. Furthermore, when comparing the control and Nano-ZnO-fed rabbits, serum testosterone concentrations increased significantly (P < 0.05) in the treated groups. In addition, compared to the other groups, the 50 mg/kg Nano-ZnO group had the highest cecal Lactobacilli spp. count. These findings suggest that supplementing Californian male rabbits with 50 mg/kg dietary Nano-ZnO enhanced CP and EE digestibility, cecal Lactobacilli spp., as well as serum testosterone levels, and decreased serum ALT and AST levels under hot climatic conditions.

Use of zinc oxide nanoparticles in the growing rabbit diets to mitigate hot environmental conditions for sustainable production and improved meat quality

Background

This study evaluated the modulatory effects of zinc oxide nanoparticles (ZnO-NPs) supplementations on the productive performance, blood biochemistry, carcass criteria, and meat quality of White New Zealand rabbits reared under hot conditions. A total of 125 White New Zealand male rabbits (body weight, “650 ± 11”, 30 days old) were assigned to five treatment diets: basal diets supplemented with ZnO-NPs at 0, 20, 40, 60, or 80 mg/kg for 60 days. Each treatment was replicated 25 times with one rabbit each.

Results

The body weight (BW), BW gain, and feed intake linearly increased with zinc oxide nanoparticle supplements. Supplementation of ZnO-NPs at 20, 40, 60, and 80 mg/kg significantly improved (linear, P < 0.05) the feed conversion ratio compared to the control group. Moreover, supplementation of ZnO-NPs at these inclusions 20, 40, 60, and 80 mg/kg significantly (P < 0.05) decreased the serum cholesterol, alanine aminotransferase, and aspartate aminotransferase, creatinine, and urea compared to control group. The lipid oxidation was lower, and the water holding capacity of rabbit meat was improved (P < 0.001) in rabbits fed on 20, 40, 60, and 80 mg/kg ZnO-NPs supplemented diets compared to control.

Conclusion

The results suggested that dietary supplementation of ZnO-NPs (20–80 mg/kg) can mitigate the negative impacts of heat stress on rabbit performance and health. Its supplementation improved growth performance and meat physicochemical properties, and blood biochemistry parameters of White New Zealand rabbits.

Impacts of Heat Stress on Rabbit Immune Function, Endocrine, Blood Biochemical Changes, Antioxidant Capacity and Production Performance, and the Potential Mitigation Strategies of Nutritional Intervention

Heat stress has become a widespread concern in the world, which is one of the major environmental stressors and causes substantial economic loss in the rabbit industry. Heat stress leads to multiple damages to the health of rabbits, such as organ damage, oxidative stress, disordered endocrine regulation, suppressed immune function and reproductive disorders, ultimately, induces the decreased production performance and increased mortality. Nutritional approaches, including feeding strategies, adjusting feed formula, and supplementing vitamins, minerals, electrolytes, Chinese herbal medicines, and functional active substances to the feed, were reported to mitigate the detrimental effects of heat stress in rabbits. Therefore, elucidating the damage of heat stress to rabbits; proper management and nutritional approaches should be considered to solve the heat stress issue in rabbits. This review highlights the scientific evidence regarding the effects of heat stress on rabbit's immune function, endocrine, blood biochemical changes, antioxidant capacity and production performance, and the potential mitigation strategies of nutritional intervention to alleviate heat stress in rabbits; which could contribute to develop nutritional strategies in relieving heat stress of rabbits.

Effect of Medicinal and Aromatic Plants on Growth, Digestibility and Carcass in New Zealand White Rabbits

&lt;b&gt;Background and Objective:&lt;/b&gt; Herbs, spices and botanicals have been demonstrated to improve animal performance and increase nutritional availability. So, the present study aimed to determine the effect of adding each of rosemary leaves, thyme leaves, black cumin seeds and fenugreek seeds at a level of 0.5% to the diets on growth performance, nutrient digestibility and carcass traits of growing New Zealand white rabbits. &lt;b&gt;Materials and Methods:&lt;/b&gt; Sixty growing New Zealand white rabbits, 425-gram average body weight, kept from 4-11 weeks of age, divided into 5 groups to examine 4 experimental herbs (rosemary, thyme, black cumin and fenugreek) compared with the control group. Growth performance, nutrients digestibility and carcass traits were measured. &lt;b&gt;Results:&lt;/b&gt; A significant improvement in feed conversion ratio and a significant increase in both final body weight, body weight gain in rabbit groups fed the 4 tested feed additives diets compared to the control group was shown. Otherwise, rabbit groups fed these diets recorded a significantly higher value of nutrient digestibility, Dry Matter (DM), Crude Protein (CP), Crude Fiber (CF), Ether Extract (EE) and Nitrogen-Free Extract (NFE), than the control group. Giblets (%) was significantly higher in rabbits group fed the control diet than other experimental rabbit groups while the opposite trend was noticed with dressing percent. In addition, rabbit groups fed the different feed additives diets achieved better economic efficiency than the control group. &lt;b&gt;Conclusion:&lt;/b&gt; Data of the present study cleared that rosemary, thyme, black cumin and fenugreek had an appositive effect on the performance of growing New Zealand rabbits and higher economic efficiency.

Thyme oil alleviates Ova-induced bronchial asthma through modulating Th2 cytokines, IgE, TSLP and ROS

Bronchial asthma (BA) is a heterogeneous allergic respiratory disease with diverse inflammatory symptoms, pathology, and responses to treatment. Thyme is a natural product which is consisted of multiple phenolic compounds of therapeutic significance for treatment of cough and bronchitis. This study evaluated the efficacy of thyme oil against ovalbumin (OVA)-induced BA in an experimental rabbit model. Forty male rabbits were divided into four equal groups [control group (G1), OVA (G2), thyme oil (G3), and OVA plus thyme oil (G4)]. Animals were treated for 30 days, and clinical, histopathological (HP), histochemical (HC), immunohistochemical (IHC), morphometric, biochemical and flow cytometry methods were performed, followed by statistical analysis. All used methods revealed normal structure of the lung tissues in rabbits of G1 and G3. In contrast, the clinical examination of G2 rabbits revealed an obvious increase in the respiratory rate, sneezing and wheezing, whereas the HP, HC and IHC techniques exhibited substantial inflammatory changes in the peribronchio-vascular lung tissues with thinning, degeneration, apoptosis (using the TUNEL assay), necrosis, and shedding of the airway epithelium. Furthermore, the morphometric results confirmed significant increases in the numbers of inflammatory cells, goblet cells, eosinophils and apoptotic cells from (12, 0, 2, 2 cells) to (34,10, 16, 18 cells) respectively, as well as the area percentage of collagen fiber deposition and immunoexpression of eotaxin-1/10 high power fields. Additionally, the biochemical results revealed significant increases in the serum levels of TSLP, IL-4, IL-5, IL-9, IL-13, IgE and eotaxin-1 cytokines from (140, 40, 15, 38, 120, 100, 48) pg./ml to (360, 270, 130, 85, 365, 398, 110) pg./ml respectively, while analysis of ROS by flow cytometry revealed remarkable oxidative stress effects in G2 rabbits. On the other hand, treatment of rabbits with thyme oil in G4 substantially alleviated all OVA-induced alterations. Overall, our findings indicate for the first time that thyme oil can ameliorate OVA-induced BA via its immunomodulatory, anti-inflammatory, antiapoptotic, and antioxidant effects on the lung tissues of rabbits.

Effect of consumption of I, Se, S and nanoaquacitrates on hematological and biochemical parameters of the organism of rabbits

Using nanotechnologies to obtain compounds of mineral substances is promising because of the importance of the amount of mineral substances, but the limiting factor is particularly their bioavailability in the digestive tract. The conducted studies determined the stimulating effect of nanoaquachelates of separate biogene microelements on the course of biochemical processes of the organisms of animals, their productivity and quality of the obtained products. However, the mechanisms of impact of carboxylates of separate elements and their combinations on functioning of physiological systems of various species of animals, level of transformation of these elements into the products and their biological value remain unstudied. Therefore, the objectives of the study were changes in hematological biochemical and productive parameters of the organisms of rabbits consuming I, Se, S, the impacts of these elements on their organism from the 53 to 85th days of life. Studies were performed on young Termonde rabbits. Animals of experimental groups I, II, III, and IV were fed with feeds of the diet of the control group for 24 h with water containing solution of І, Se, S calculated respectively as 2.5, 5.0, 10.0 and 20.0 µg of І/L of water. The experiment lasted 45 days, including a 12 day preparation period and 33 day experimental. On the 53rd day of life of animals in the preparation period, and 68th and 85th days of life in the experimental periods (15th and 33rd days of watering with supplements), we collected samples of blood from the marginal ear vein of 6 animals (3 males and 3 females) of the group for hematological and biochemical studies. We determined that watering with the solution of microelements І, Se, S led to changes in the overall amount of white blood cells, making it 17.1% lower in the blood of animals of the experimental group II, 26.2% higher in group ІІІ on the 15th day, and 12.0% higher in group IV on the 31st day of the experiment compared with the control. Absolute amounts of lymphocytes, monocytes and granulocytes by the periods of the study were observed to have no significant changes throughout the study, though their parameters were within the physiological values compared with the control. The amount of red blood cells in the blood of rabbits of experimental groups І, ІІ and ІІІ was higher respectively by 8.1%, 5.7% and 12.0% at the first stage of the study and 18.1%, 13.3%, 24.5% and 24.9% higher in animals of experimental groups І, ІІ; ІІІ and ІV at the final stage of the study compared with the control group. Hemoglobin concentration in blood of rabbits of experimental groups II and III during the study was significantly higher. Hematocrit value in blood of rabbits of experimental groups I–III was significantly higher on the 33rd day of the experiment compared with the control. Consumption of solution of microelements in the amount of 10.0 µg of I/L by the animals of experimental group III led to 15.1% higher content of total protein in the blood on the 33rd day of the study compared with the control group of animals. The level of creatinine was no higher than the physiological parameters and was 9.2%, 15.0% and 15.4% higher in the blood of rabbits of experimental groups II, III, IV on the 33rd day of the experiment compared with the control group. No significant changes in the content of triacylglycerols in the blood of rabbits of the experimental groups were seen throughout the study. However, the content of cholesterol in the blood of rabbits of experimental groups III and IV was significantly higher at the first stage compared with the control group. Further, it is practical to study physiologically substantiated amounts of solution of microelements І, Se, S in the diet of mother rabbits to determine their effect on their ability to become pregnant, reproductive function, milk production and survival of offspring.

Combined Supplementation of Nano-Zinc Oxide and Thyme Oil Improves the Nutrient Digestibility and Reproductive Fertility in the Male Californian Rabbits

Simple Summary

The present study aimed to investigate the beneficial effects of supplementing zinc oxide nanoparticles (ZnO-NPs), thyme oil (THO), or their combination on the reproductive parameters, nutrient digestibility coefficients, and some blood metabolites of male Californian rabbits. Results showed an improvement in the nutrients digestibility, liver and kidney functions, testosterone concentration, and semen characteristics (semen volume, sperm motility, vitality, and morphology). ZnO-NPs were more effective in improving the male fertility, while THO showed a marked improvement in nutrient digestibility. Therefore, the inclusion of ZnO-NPs, or THO, or both is recommended for a rabbit feeding regimen to improve the feeding profitability.

Abstract

The present study aimed to determine the effects of zinc oxide nanoparticles (ZnO-NPs), thyme oil (THO), or their combination on the nutrient digestibility coefficients, reproductive parameters, and some blood metabolites of male Californian rabbits. One hundred rabbits, 29-weeks of age (initial body weight 3.48 ± 0.08 kg) were randomly distributed into four groups, 25 rabbits each. Treatment groups were fed a control diet, a control diet supplemented with ZnO-NPs (100 mg/kg), THO (500 mg/kg), or combination of ZnO-NPs (100 mg/kg) and THO (500 mg/kg). The feeding trial lasted for 35 days. Results showed improvements in dry matter, crude protein, ether extract, and crude fiber in ZnO-NPs, THO, and their combination treated groups compared to those of control. Furthermore, semen volume, sperm motility, vitality, and morphology were significantly improved (p < 0.01) in ZnO-NPs and THO groups rather than the control. Both ZnO-NPs and THO, as either individual or combined treatments significantly improved the serum alanine amino-transferase (ALT), aspartate amino-transferase (AST), urea, and creatinine compared to the control. Moreover, serum concentrations of testosterone were significantly increased in rabbits supplemented with ZnO-NPs, THO, or their combination compared to those of control (p < 0.05). In conclusion, ZnO-NPs, THO, or their combination improved the digestibility of nutrients, liver/ kidney functions, semen characteristics, and testosterone concentration in male rabbits.

Productive and Physiological Response of Male Rabbits to Dietary Supplementation with Thyme Essential Oil

Simple Summary

The present study was carried out to compare the potential effects of the levels of thyme essential oil on the productive performance and serum metabolic profile of male rabbits. Rabbits were assigned to five dietary treatments including a basal diet as a negative control, a basal diet supplemented with an antibiotic as a positive control, and a basal diet supplemented with 60, 120, or 180 mg/kg of thyme essential oil. The main results showed that the levels of thyme essential oil contributed to the improvement of productive and the physiological response compared with the negative and positive control of male rabbits.

Abstract

The present study aimed at assessing the efficiency of thyme essential oil (TEO) as an alternative to antibiotics for improving the productive performance and serum metabolic profile of male rabbits. A total of one hundred and fifty 70-day-old male Californian rabbits were assigned to five dietary treatments, including a basal diet as a negative control (NC), a basal diet supplemented with an antibiotic as a positive control (PC), and a basal diet supplemented with 60, 120, or 180 mg/kg of TEO. The experiment period lasted for 60 days. Supplementation of TEO levels significantly (P < 0.01) increased daily body weight gain and improved feed conversion ratio of male Californian rabbits compared to NC and PC groups. Similarly, the TEO remarkably enhanced the semen characteristics of rabbits compared to NC and PC groups. Supplementation of TEO significantly decreased aspartate transaminase, alanine transaminase, urea, and creatinine compared with NC and PC groups. Supplementation with TEO increased serum testosterone concentration compared to NC and PC treatments. Our data demonstrate that TEO levels up to 180 mg/kg can play a major role as an alternative to dietary antibiotics, in improving the productive performance, semen quality, testosterone levels, and the kidney and liver functions in California male rabbits.

New Tricks for Old Guys: Recent Developments in the Chemistry, Biochemistry, Applications and Exploitation of Selected Species from the Lamiaceae Family

Lamiaceae is one of the largest families of flowering plants comprising about 250 genera and over 7,000 species. Most of the plants of this family are aromatic and therefore important source of essential oils. Lamiaceae are widely used as culinary herbs and reported as medicinal plants in several folk traditions. In the Mediterranean area oregano, sage, rosemary, thyme and lavender stand out for geographical diffusion and variety of uses. The aim of this review is to provide recent data dealing with the phytochemical and pharmacological studies, and the more recent applications of the essential oils and the non-volatile phytocomplexes. This literature survey suggests how the deeper understanding of biomolecular processes in the health and food sectors as per as pest control bioremediation of cultural heritage, or interaction with human microbiome, fields, leads to the rediscovery and new potential applications of well-known plants.

Synbiotic as eco-friendly feed additive in diets of chickens under hot climatic conditions

This study was conducted to investigate the effect of synbiotic supplementation on performance, survivability rate, microbial populations, ammonia production, liver function, and meat physicochemical properties as well as carcass characteristics in broiler chicks under hot climatic conditions. A total of 320 one-day-old Ross 308 broiler chicks were randomly assigned to 4 dietary treatments as follows: control diet without synbiotic (S0), synbiotic at 500 mg/kg for starter diet and 250 mg/kg grower diet (S1), synbiotic at 1000 mg/kg for starter diet and 500 mg/kg grower diet (S2), and synbiotic at 1500 mg/kg for starter diet and 750 mg/kg grower diet (S3). Each treatment had 10 replicate pens with 8 birds. Diets were formulated using corn, sorghum, soybean meal, corn gluten meal and sunflower oil as major ingredients to meet the nutrient requirements for starter (1 to 21 d) and grower (22 to 35 d) periods. The experiment lasted for 35 d. The results showed that body weight and body weight gain were increased (linear, P<0.01) with the increase in dietary synbiotic feeding during the trial period. In addition, the feed intake linearly increased (P < 0.001) with increasing synbiotic levels and, in turn, caused linear improvements (P < 0.001) in feed conversion values. Interestingly, E. coli, Salmonella and Shigella were decreased (P < 0.001) by supplemental synbiotic levels compared to the control group during the entire study. Furthermore, there was beneficial effects on excreta ammonia reduction (P < 0.001) by supplementation of synbiotic groups compared to control. Increasing synbiotic levels decreased (P < 0.001) drip loss and cook loss percentage of breast and leg muscles without any significant changes in pH values. Dressing, breast, and leg percentages were increased, and abdominal fat percentage was decreased by supplemental synbiotic levels. In conclusion, this investigation demonstrated that synbiotic can be used as an effective feed additive to improve productive performance, meat quality, and ammonia reduction as well as decrease microbial populations of broiler chicks in hot climatic regions.

Peppermint and its respective active component in diets of broiler chickens: growth performance, viability, economics, meat physicochemical properties, and carcass characteristics

This study was conducted to investigate effects of dietary peppermint leaves and menthol supplementations on performance, survivability rate, cost economics, meat physicochemical properties, and carcass characteristics of broiler chicks. A total of 384 1-day-old, unsexed Ross 308 broiler chicks, were divided into 2 experiments. Each experiment included 192 birds that were assigned to 4 dietary treatments that included peppermint leaves at concentrations of 0, 5, 10, or 15 g/kg in the first experiment or menthol at concentrations of 0, 26, 52, or 78 mg/kg in the second experiment. Each treatment had 6 replicate pens with 8 birds. The experiments lasted for 35 D. The peppermint leaves contained 1.48% essential oil that contained 35.1% menthol, and the levels of menthol were selected based on the concentrations in peppermint leaf levels. Body weight and body-weight gain increased with the increase in dietary peppermint leaves (linear, P < 0.01) and menthol concentrations (linear, quadratic, P < 0.01) during the trial periods. In addition, the feed intake linearly increased (P < 0.01) with increasing peppermint leaves or menthol levels and, in turn, caused linear improvements (P < 0.01) in feed conversion values. Interestingly, a lower mortality rate was recorded in the supplementation groups and, therefore, a higher net return was observed. However, pH values and drip loss percentage of breast and leg muscles were not affected by either dietary peppermint levels or menthol levels. Increasing peppermint or menthol levels decreased (P < 0.001) cook-loss percentage of breast and leg muscles. On the other hand, dietary supplementation of peppermint leaves or menthol had no effect (P ≥ 0.05) on the relative weights of dressing, breast, leg, liver, heart, gizzard, spleen, or pancreas. Interestingly, abdominal fat percentage was decreased by either supplemental peppermint or menthol. Hence, the present investigation demonstrates that peppermint leaves can be used as an effective novel nutritional bio-agent up to 15 g/kg to improve the performance of broiler chicks, mainly due to its active component.

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.