Impacts of bentonite supplementation on growth, carcass traits, nutrient digestibility, and histopathology of certain organs of rabbits fed diet naturally contaminated with aflatoxin

An overview of mycotoxicoses in rabbits

Mycotoxicoses are usually a consideration in large animal species but can affect companion animals as well. Due to increasing interest and the ease of using rabbits as laboratory models, a growing number of published experimental studies discuss the effects of various mycotoxins on this species. However, the available evidence is fragmented and heterogeneous, and has not recently been collated in a review, to my knowledge. Although mycotoxicoses in rabbits are typically subclinical, clinical signs can include weight loss, anorexia, gastrointestinal disorders, stunted growth, reproductive abnormalities, and susceptibility to infections. An antemortem diagnosis typically relies on a comprehensive clinical history, and assessment of clinical signs and relevant laboratory findings, with confirmation of exposure achieved through the measurement of mycotoxin concentrations in feed or target organs. My review focuses on the clinicopathologic and histopathologic effects of the mycotoxins most important in rabbits, including fumonisins, ochratoxins, aflatoxins, trichothecenes, and zearalenone. This review offers a thorough overview of the effects of mycotoxins in rabbits, serving as a one-stop resource for veterinary practitioners, diagnosticians, and researchers.

Investigation of pesticide residues level on commonly consumed leafy vegetables picked from the central market in Jeddah, Saudi Arabia

This study aimed to investigate the presence of pesticide residues in a variety of commonly consumed leafy vegetables, including Grape leaves, Lettuce, Arugula, Spinach, Purslane, Ocimum, Parsley, Jew's mallow, Celery, Coriander, and Mint. A total of 100 samples were collected from the Central Market of Jeddah, Kingdom of Saudi Arabia. Our methodology involved employing the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) extraction method in combination with Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) to analyze a comprehensive database of 237 distinct pesticides. The range for limit of detection (LOD) and limit of quantification (LOQ) of the method were 0.0001 to 0.0014 mg. Kg-1 and 0.0010 to 0.0064 mg. Kg-1 for tested pesticides, respectively. The recoveries were in the range of 70-172.9%, with a relative standard deviation (RSD) of less than 19.0% for all tested pesticides. The results revealed that 60% of the analyzed samples were free from pesticide residues, while 40% exhibited contamination with 17 different pesticide residues. Notably, the most prevalent pesticide detected was Triallate in the Ocimum samples, followed by Metalaxyl in Grape leaves, Mint, and Spinach, and Methomyl in Celery. Approximately 45% of the samples contained pesticide residues that fell below or were equal to the European Union Maximum Residue Levels (EU MRLs), while the remaining 55% exceeded these MRLs. Remarkably, high pesticide concentrations were observed in all Ocimum samples (Triallate, Pyridaben, Hexythiazox, Imidacloprid), 67% of Grape leaves (Metalaxyl, Azoxystrobin, Difenoconazole Isomer), and 40% of Celery (Azoxystrobin, Methomyl). In conclusion, this study sheds light on the contamination levels of commonly consumed domestically produced and purchased leafy vegetables in the Central Market of Jeddah. To ensure food safety and the well-being of consumers, we strongly recommend enhanced scientific assessments and continued monitoring of pesticide usage in agricultural practices.

Detoxification impacts of dietary probiotic and prebiotic supplements against aflatoxins: an updated knowledge

The widespread prevalence of food pollutants seriously threatens human and animal health. Mycotoxins are secondary metabolites primarily formed by toxigenic fungal genera, including Aspergillus, Penicillium, Fusarium, and Alternaria, demonstrating one of the principal pollutants in diets or feed products. Mycotoxin contamination in food can harm health, including stunted development, immune system suppression, infertility, vomiting, and gastrointestinal and cancerous conditions. These effects can occur both acutely and chronically. The complex food chain can be contaminated with mycotoxins at any point, including during harvest, industrial processing, shipping, or storage, putting the food sector under societal pressure owing to the waste generated by infected goods. One of the biological controls of mycotoxin is provided by probiotics and prebiotics, controlled as foods and dietary supplements made of bacteria or yeast. Aflatoxin's bioavailability and gastrointestinal absorption can be reduced using various probiotics and prebiotics.

A meta-analysis of the effects of clay mineral supplementation on alkaline phosphatase, broiler health, and performance

The crucial constraint in the broiler production sector is feed efficiency; many feed additives have been widely employed to increase broiler growth. Nonetheless, some of these substances exacerbate health and animal-based food product safety concerns. This meta-analysis examines the effect of clay minerals on alkaline phosphatase (ALP), broiler health, and performance. Metadata was constructed from 369 data items that were harvested from 86 studies. The addition of clay minerals was set as a fixed effect and the difference between experiments was established as a random effect. The metadata were fitted using a linear mixed model. Due to the presence of clay minerals, growth performance as assessed by body weight (BW), average daily gain (ADG), and performance efficiency index (PEI) increased significantly (P < 0.01). In the total period, the increases of BW, ADG, and PEI were 4.12 g, 0.0714 g/d, and 0.648, respectively, per unit of clay minerals added. Clay minerals did not affect blood serum parameters (e.g., ALP and calcium). The IgA and IgM concentrations in the jejunum and ileum were significantly greater (P < 0.01) in the starter phase. Among clay minerals, broilers fed diets with aluminosilicate, halloysite, kaolin, and zeolite consistently exhibited higher (P < 0.05) BW, ADG, PEI, and lower feed conversion ratio (P < 0.05) in the finisher phase. Aluminosilicate was the only clay that increased (P < 0.05) secretory IgA concentration in both jejunum and ileum. In conclusion, clay minerals could be used as a growth promoter, especially during the finisher phase, without adversely affecting feed intake, liver function, and mineral metabolism in broiler chickens. Aluminosilicate was superior in improving the mucosal immunity status of broiler chickens.

SeMet attenuates AFB1-induced intestinal injury in rabbits by activating the Nrf2 pathway

The aim of this study was to investigate the role of selenomethionine (SeMet) in alleviating AFB1 induced intestinal injury by inhibiting intestinal oxidative stress. Forty 35-day-old rabbits were divided randomly into 4 groups (control group, AFB1 group, 0.2 mg/kg Se + AFB1 group, 0.4 mg/kg Se + AFB1 group). From the first day of the experiment, the two treatment groups were fed 0.2 mg/kg SeMet or 0.4 mg/kg SeMet daily for 21 days. On the 17th day, all rabbits in the model group and the two treatment groups were given intragastric AFB1 daily for 5 days. The ADG, ADFI and FCR of the rabbits were examined. Rabbit jejunum tissue was collected for hematoxylin- eosin staining (HE), PCNA detection, immunofluorescence and WB. Intestinal tissue IL-1β, IL-6 and TNF-α were examined by enzyme-linked immunosorbent assay (ELISA). The results showed that the production performance was decreased, the levels of ROS and MDA were increased in intestinal tissues, the activity of antioxidant enzymes was decreased and the expression levels of Nrf2 and HO-1 were decreased in AFB1-exposed rabbits. In addition, AFB1 induces an inflammatory response in the jejunum and promotes the expression of TNF-α, IL-6 and IL-1β. SeMet pretreatment significantly improved the performance of the rabbits, alleviated intestinal oxidative stress and the inflammatory response. Therefore, we confirmed that SeMet protects against AFB1 induced oxidative damage and improves productivity in rabbits by activating the Nrf2/HO-1 signaling pathway.

Growth performance, tissue precipitation, metallothionein and cytokine transcript expression and economics in response to different dietary zinc sources in growing rabbits

The impact of different dietary zinc sources on the growth, serum metabolites, tissue zinc content, economics and relative expression of cytokine and metallothionein genes was evaluated in this study. A total of 120 35-day-old male New Zealand White (NZW) rabbits were randomly distributed into four dietary experimental groups with 10 replicates per group and 3 animals per replicate. The control group was fed basal diet with a Zn-free vitamin-mineral premix; the other three groups received control basal diet supplemented with 50 mg/kg level with zinc oxide (ZnO; as inorganic source), Zn-methionine (Zn-Met; as organic source) and zinc oxide nanoparticles (nano-ZnO). The results indicated that Zn-Met and nano-ZnO groups significantly improved body weight, daily weight gain (DWG), feed conversion ratio (FCR) and nutrient digestibility, as well as decreased mortality, compared to ZnO and control groups. Zn-Met and nano-ZnO significantly reduced serum total cholesterol but did not affect serum proteins and liver function. Nano-ZnO supplemented group also recorded the highest value of serum alkaline phosphatase (ALP), insulin-like growth factor (IGF-1) and lysozymes compared to other groups. Nano-ZnO supplementation had increased hepatic Zn and Cu content and decreased faecal Zn content. Also nano-ZnO group recorded higher expression levels of genes encoding for metallothionein I and metallothionein II, interleukin-2 and interferon-γ in the liver of rabbits. The findings of this study demonstrated zinc nanoparticles, and organic zinc supplementation had improved growth performance and health status of growing rabbits than inorganic zinc oxide.

Effects of Phenolic-Rich Onion (Allium cepa L.) Extract on the Growth Performance, Behavior, Intestinal Histology, Amino Acid Digestibility, Antioxidant Activity, and the Immune Status of Broiler Chickens

The effect of phenolic-rich onion extract (PROE), as a feed additive, was evaluated on the growth, carcass traits, behavior, welfare, intestinal histology, amino acid ileal digestibility "AID%," and the immune status of broiler chicks for 35 days. A total number of 400, 1-day-old broiler chicks (45.38 g ± 1.35) were allocated to four different treatments with 10 replicates each (100 chicks/treatment) consisting of: T1, basal diet without additives (control treatment) (PROE0); T2, basal diet + phenolic-rich onion extract (1 g/kg diet) (PROE1); T3, basal diet + phenolic-rich onion extract (2 g/kg diet) (PROE2); and T4, basal diet + phenolic-rich onion extract (3 g/kg diet) (PROE3). An increase in the final body weight "FBW," bodyweight gain "BWG," and feed consumption was observed (P < 0.05) at different PROE levels. Also, the thymus and bursa percentages were increased in the PROE2 and PROE3 treatments (P < 0.05). The chicks fed on PROE supplemented diets had increased frequency of feeding and drinking and showed comfortable behavior (P < 0.05) with lesser aggression (P < 0.05). Additionally, an increase was observed in the antioxidant enzyme activity, phagocytic %, phagocytic index, and serum lysozyme activity in PROE supplemented treatments, with the best outcome reported in the PROE3 treatment (P < 0.01). IgM was increased in the birds fed with PROE2 and PROE3 diets (P < 0.01). PROE supplementation increased the AID% of lysine and methionine (P <0.01), PROE3 treatment increased the AID% of threonine (P < 0.05), and PROE2 and PROE3 treatments increased the AID% of leucine and isoleucine (P < 0.05). Besides, PROE2, and PROE3 treatments increased the villus height and width, mucosal thickness, and goblet cell count from the duodena, jejuna, and ilea (P < 0.05) compared to control treatment. Based on these results, we concluded that the dietary addition of phenolic-rich onion extracts can improve the growth rate of broiler chicken by improving the AID% of amino acids and intestinal histology. Also, it can improve the welfare, antioxidant enzymes activity, and immune status of the birds. Phenolic-rich onion extracts can be used as a natural growth promoter in the poultry feed for good health and improved performance.

Are the energy matrix values of the different feed additives in broiler chicken diets could be summed?

BACKGROUND

The aim of this study is to investigate whether the energy matrix values of the nonstarch polysaccharide- (NSP-) degrading enzymes, bioemulsifier (LYSOFORTE®), guanidinoacetic acid (CreAMINO®), or their combinations could be summed. The effects of these additives on the growth performance, carcass traits, and economic value of the broiler chicken diets were evaluated. A total of 525-one-day-old Ross chicks with an initial body weight of 42.96 ± 0.87 g were haphazardly allocated into seven groups with five replicates. The seven experimental treatments are as follows: (1) basal diet with no additives (breeder recommendation), which is the control group, (2) basal diet minus 100 kcal/kg supplemented with 0.02% NSP-degrading enzymes (NSP), (3) basal diet minus 50 kcal/kg supplemented with 0.025% emulsifier (LYSOFORTE®), (4) basal diet minus 50 kcal/kg supplemented with 0.06% guanidinoacetic acid (CreAMINO®), (5) basal diet minus 150 kcal/kg supplemented with a mixture of NSP and LYSOFORTE® (NSPL), (6) basal diet minus 100 kcal/kg supplemented with a mixture of NSP and CreAMINO® (NSPC), and (7) basal diet minus 200 kcal/kg supplemented with a mixture of NSP, LYSO, and CreAMINO® (NSPLC). The experiment lasted for 35 days.

RESULTS

It was found that the final body weight, body weight gain, and relative growth rate were significantly higher in birds fed diets supplemented with NSPL, NSPC, CreAMINO, and LYSO with the reduced energy matrix value. The overall feed conversion ratio was significantly improved due to the supplementation of NSPC, CreAMINO, NSPL, and LYSO with the reduced energy matrix value compared to the control group. Moreover, no significant effect on the carcass criteria was observed by the different treatments. As a result of the dietary supplementation with NSPL, NSPC, CreAMINO®, and LYSO with the reduced energy matrix value, the net profit, total return, economic efficiency, and performance index were increased and the cost of feed per kg of body weight gain was decreased.

CONCLUSION

The energy matrix value of NSPL, NSPC, CreAMINO®, and LYSOFORTE could be established in the diets of broiler chickens to improve the growth performance and economic efficiency.

Dietary Supplementation with sodium bentonite and coumarin alleviates the toxicity of aflatoxin B1 in rabbits

Eighty-four male New Zealand White rabbits with average body weight 778 ± 65 g were blocked into four groups to evaluate the ability of sodium bentonite and coumarin in alleviating the toxicity of aflatoxin B1. The first group was fed on a diet without any treatment (CON), while the remaining three diets were added with aflatoxin B1 at 0.25 ppm diet. Diet fed to the third and fourth group of rabbits were further supplemented with sodium bentonite at 5 g/kg (SOB) and coumarin at 5 g/kg (COU) of the diet, respectively. Feeding aflatoxin-contaminated diet (AFL) caused necrosis of liver tissue and reduced the weight gain, average daily gain, feed conversion ratio, nutrient digestibility coefficients, and nitrogen balance of rabbits. This, in turn, was reflected as a reduction in carcass characteristics. The serum collected from rabbits fed aflatoxin-contaminated diet showed decreased levels of total protein, albumin, globulin, glucose, total cholesterol, and triglycerides, and increased concentrations of urea, creatinine, and liver enzymes. Further, aflatoxin diet increased the cecal pH, and decreased the ammonia nitrogen, total volatile fatty acids, and individual fatty acids proportion of cecal fluid. Supplementing sodium bentonite and coumarin at 5 g/kg diet reduced the negative effects of aflatoxin B1 on growth performance, digestibility of nutrients, biochemical parameters, carcass characteristics, and cecal fermentation profile. Furthermore, the coumarin-supplemented group showed better body weight gains and carcass weights compared to the rabbits fed with diets containing sodium bentonite. In conclusion, both sodium bentonite and coumarin supplementation was beneficial in ameliorating the toxicity of aflatoxin B1. Further, the increased body weight gains and better-feed conversion in coumarin-supplemented rabbits project the coumarin as a better anti-aflatoxigenic supplement.

Effect of dietary supplementation with insect fats on growth performance, digestive efficiency and health of rabbits

BACKGROUND

The present work aimed at evaluating the effect of the dietary replacement of soybean oil (S) by two types of insect fats extracted from black soldier fly larvae (H, Hermetia illucens L.) and yellow mealworm larvae (T, Tenebrio molitor L.) on growth performance, nutrient digestibility, blood parameters, intestinal morphology and health of growing rabbits.

METHODS

At weaning, 200 crossbred rabbits (36 days old) were allotted to five dietary treatments (40 rabbits/group): a control diet (C) containing 1.5% of soybean oil and four experimental diets where soybean oil was partially (50%) or totally (100%) substituted by H (H50 and H100) or T (T50 and T100) fats. Total tract digestibility was evaluated on 12 rabbits per treatment. The growth trial lasted 41 d and, at slaughtering (78 days old), blood samples were collected from 15 rabbits per treatment, morphometric analyses were performed on duodenum, jejunum and ileum mucosa, and samples of liver, spleen and kidney were submitted to histological evaluation.

RESULTS

No difference was observed between the control and the experimental groups fed insect fats in terms of performance, morbidity, mortality and blood variables. The addition of H and T fats did not influence apparent digestibility coefficients of dry matter, protein, ether extract, fibre fractions and gross energy. Gut morphometric indices and organ histopathology were not affected by dietary inclusion of H and T fats.

CONCLUSIONS

H and T fats are suitable sources of lipid in rabbit diets to replace soybean oil without any detrimental effect on growth performance, apparent digestibility, gut mucosa traits and health.