The Influence of Chicken Egg Lysozyme or Zinc-Bacitracin Antibiotic on the Growth Performance, Antibacterial Capacity, Blood Profiles, and Antioxidative Status of Rabbits: A Comparative Study

Simple Summary

Despite the beneficial role of antibiotics in reducing bacterial infection in rabbits, there is an indirect harmful influence on human health. Thus, replacing antibiotics with friendly alternatives is a suitable strategy to protect the performance and welfare of rabbits. This study aimed at comparing the effects of including dietary egg lysozyme and zinc bacitracin antibiotic (ZnB) on the productivity and health conditions of rabbits. The results show a marked enhancement of the growth performance, antibacterial capacity, blood health, and antioxidative status in rabbits treated with egg lysozyme compared with those treated with ZnB. Thus, using egg lysozyme is recommended to replace the usage of ZnB in rabbit production.

Abstract

Dietary egg lysozyme has beneficial roles in the growth performance and health conditions of animals. The study was performed using 90 multicolored rabbits in three groups (each replicate with thirty rabbits). In the control group, rabbits were fed a diet without zinc bacitracin (ZnB) or egg lysozyme, while the second and third groups were treated with ZnB and lysozyme additive at 100 mg/kg, respectively. After eight weeks, the final weight and body weight gain (BWG) of rabbits fed dietary egg lysozyme and ZnB additives were meaningfully increased (p < 0.05). Nevertheless, the feed conversion ratio (FCR) was markedly decreased by dietary egg lysozyme and ZnB (p < 0.05). Interestingly, dietary egg lysozyme resulted in higher final weight and BWG and lower FCR than rabbits treated with ZnB (p < 0.05). Rabbits treated with egg lysozyme and ZnB additives had markedly lower populations of Clostridium spp. and Escherichia coli (p < 0.05) compared with the control. However, the counts of Lactobacillus and total bacteria were meaningfully increased in the the intestines of rabbits treated with egg lysozyme and ZnB (p < 0.05). The blood total protein and globulin of rabbits fed dietary egg lysozyme and ZnB additives were meaningfully increased (p < 0.05). Blood creatinine was significantly lowered by dietary egg lysozyme compared with the control and ZnB-treated rabbits (p < 0.05). The levels of blood urea, ALT, and AST were markedly lowered (p < 0.05) by dietary egg lysozyme and ZnB. The gene expressions of superoxide dismutase 1 (SOD1) and glutathione peroxidase (GPX) in the liver of rabbits fed dietary egg lysozyme and ZnB additives were markedly upregulated (p < 0.05) compared with the control. Dietary egg lysozyme resulted in higher expression of SOD1 and GPX genes than rabbits treated with ZnB (p < 0.05). In conclusion, the inclusion of egg lysozyme could replace the inclusion of ZnB in the diets of rabbits.

Effect of feeding wheat middlings and calcium lignosulfonate as pellet binders on pellet quality growth performance and lipid peroxidation in broiler chickens

Basal diets supplemented with 4 kg Ca-LS/ton of diet. Pellet quality characteristics (per cent fines, the present study was conducted to evaluate the influence of wheat middlings (WM) and calcium lignosulfonate (Ca-LS) as pellet binders on the pellet quality characteristics, growth performance, blood parameters, nutrients digestibilities, lipid peroxidation and muscle fatty acids profile in Egyptian broiler strain. A total of 3,120 broiler chicks at 1-day of age were divided randomly into three experimental treatments with eight replicates (130 each). The first treatment was fed the basal pelleted diets without any additives, the second treatment was fed diets including 50 kg WM/ton of diet and the third treatment was fed per cent pellets, and pellet durability index) were significantly improved in WM and Ca-LS treatments compared with the control. Body weight gain was significantly increased, while feed intake was significantly decreased resulting in improving of feed conversion ratio significantly in WM group in comparison with control and Ca-LS groups (p < .05). Nutrients apparent digestibility (dry matter, crude protein and crude fibre) were significantly improved by inclusion of WM compared with control and Ca-LS. Plasma total cholesterol, and uric acid concentrations were significantly decreased by dietary WM in comparison with control and Ca-LS experimental groups. Furthermore, linoleic, alpha-linolenic and arachidonic acids contents in breast muscle were significantly increased by WM and Ca-LS, while, muscle malondialdehyde concentration was significantly decreased. It could be concluded that inclusion of WM and Ca-LS can improve pellet quality characteristics, and WM (at a level of 50 kg/ton) had positive effects on growth performance, nutrients digestibilities, lipid peroxidation and fatty acids profile in Egyptian broiler strain.

Oxidative stress, hemato-immunological, and intestinal morphometry changes induced by ochratoxin A in APRI rabbits and the protective role of probiotics

This work studied the protective effects of Aspergillus awamori against ochratoxin A (OTA)-induced toxicity in APRI maternal line rabbits. A total number of 48 APRI line weanling rabbits (5 weeks) were divided into 4 groups (12 rabbits each) and fed the basal diet, 30 ppb/kg diet of OTA, 1 g/kg diet of A. awamori, and a mixture of OTA and A. awamori for 8 weeks. OTA reduced the final body weight and weight gain as well as the intestinal villi length and thickness, whereas increased the feed intake and feed conversion ratio. Rabbits fed diets with OTA showed significantly reduced crude protein, lipids, and fibers apparent digestibility coefficients (P < 0.05). The red blood cells and hemoglobin were significantly decreased in the OTA group comparing with the other groups (P < 0.05). The blood total protein and albumin displayed significantly lower levels by OTA than the other groups. In contrast, glucose, aspartate aminotransferase (AST), alkaline phosphatase (ALP), urea, and creatinine levels were significantly increased by OTA (P < 0.05). Phagocytic activity (PA) and phagocytic index (PI) showed significantly (P < 0.05) decreased levels in OTA-contaminated group, while rabbits fed A. awamori significantly showed the highest PA and PI levels (P < 0.05). Dietary A. awamori kept the levels of PA and PI in rabbits fed OTA significantly higher than those fed without A. awamori (P < 0.05) and not significantly different from the control group (P > 0.05). Catalase (CAT) and superoxide dismutase (SOD) displayed significantly lower levels in the OTA group, while malondialdehyde (MDA) was significantly higher than the other groups (P < 0.05). Rabbits fed OTA-contaminated diets displayed significantly lower CAT and SOD and higher MDA than rabbits fed OTA combined with A. awamori (P < 0.05). Our results indicated that dietary A. awamori ameliorated the damage in APRI rabbits fed OTA through alleviation of oxidative stress and immunity.

Impact of Dietary Organic Mineral Supplementation on Reproductive Performance, Egg Quality Characteristics, Lipid Oxidation, Ovarian Follicular Development, and Immune Response in Laying Hens Under High Ambient Temperature

The objectives of this study were to investigate the impact of dietary organic mineral mixture (manganese, zinc, and copper) supplementation on reproductive performance, egg quality characteristics, and immune response in laying hens under high ambient temperature. Hens were randomly divided into three treatments: (1) control (basal diet without organic mineral mixture (Mn, Zn, and Cu) supplementation); (2) basal diet + 0.5 g/kg of organic mineral mixture; and (3) basal diet + 1 g/kg of organic mineral mixture from 30 to 38 weeks of age. Hen-day egg production and egg mass were significantly increased by dietary supplementation of 1 g/kg of organic mineral mixture, while feed intake was not affected; therefore, feed conversion ratio (FCR) was significantly improved (P < 0.01). Egg weight, albumen width, shell weight, and shell thickness were significantly increased by the dietary treatments. Serum total cholesterol and glucose were significantly decreased by organic mineral mixture supplementation. Interestingly, yolk contents of total cholesterol and malondialdehyde (MDA) were significantly decreased. Yolk contents of Zn and Cu were significantly increased, while Mn was numerically increased (P > 0.05). Dietary organic mineral mixture supplementation improved the antibody titers against avian influenza H9N1 significantly (P < 0.05) and Newcastle disease virus numerically (P > 0.05) in comparison with the control diet. It might be concluded that the inclusion of organic mineral mixture (Mn, Zn, and Cu) enhanced reproductive performance, shell quality characteristics, plasma profile, yolk mineral concentration, yolk lipid oxidation, and immune response in laying hens under high ambient temperature.

In ovo injection of nano-selenium spheres mitigates the hatchability, histopathology image and immune response of hatched chicks

In ovo injection of nano-selenium (Se) produced by lactic acid bacteria (LAB-nano-Se) was investigated on the hatchability, immune responses and the histopathological alterations in hatched chicks. The eggs (18 day age) were injected with 0.5 ml of 0.9% NaCl (normal saline, NS), while the control group was kept without injection. In the third, fourth and fifth groups, the eggs were injected with 0.5 ml of NS and LAB-nano-Se at 10, 20 and 30 μg/egg. The results revealed improved growth performance in groups injected with LAB-nano-Se when compared to the control treatment. The highest final weight and weight gain were noticed in 20 μg LAB-nano-Se/egg group (p < .05). The feed conversion ratio was reduced in all treated groups when compared to the control group (p < .05). Groups injected with LAB-nano-Se showed enhanced hatchability of the whole incubated eggs (p < .05). Total lipids and cholesterol levels were decreased significantly in groups treated with LAB-nano-Se at 10 and 20 μg/egg when compared to the non-treated group. At the same time, globulin was increased by LAB-nano-Se in ovo injection. Furthermore, the total antioxidant capacity, catalase, glutathione peroxidase, superoxide dismutase increased in groups treated with LAB-nano-Se at 10 and 20 μg/egg with insignificant (p > .05) differences with those treated with LAB-nano-Se at 30 μg/egg using in ovo injection technique. Also, higher total blood protein and phagocytosis were significantly observed in groups treated with at 10, 20 and 30 μg LAB-nano-Se/egg. The histopathological images of hatched chicks revealed that nano-Se presented normal effects on liver and kidney tissues and restored the parameters as mentioned earlier. To conclude, LAB-nano-Se exhibited beneficial effects in hatched chicks through improving immune and antioxidant activities as well as histopathological effects by using in ovo technique.

A Mixture of Exogenous Emulsifiers Increased the Acceptance of Broilers to Low Energy Diets: Growth Performance, Blood Chemistry, and Fatty Acids Traits

To investigate the influence of emulsifiers on broilers fed low-energy diets, the birds were distributed into three sets-the control was fed the basal diet, the second group was fed diets 50 kcal/kg less than control, and the third group was fed diets 50 kcal/kg less than control and supplemented with 500 g/ton of emulsifiers. The used mixture of exogenous emulsifiers contains phosphatidyl choline, lysophosphatidyl choline, and polyethylene glycol ricinoleate. Although the feed intake was not meaningfully affected by dietary low-energy level with emulsifier inclusion (P = 0.42), the weight gain and FCR were clearly enhanced (P = 0.005 and P = 0.044, respectively). Protein and lipids utilization were decreased by reducing energy level, but they were increased by emulsifier supplementation (P = 0.022 and P = 0.011, respectively). Liver thiobarbituric acid-reactive substances (TBARs) and muscle palmitic acid concentrations were decreased by reducing the energy level and emulsifier's supplementation (P = 0.014 and P = 0.042, respectively). However, muscle total lipids and α-tocopherol, oleic acid, linoleic acid, and α-linolenic acid were not affected by dietary treatments (P > 0.05). Interestingly, the plasma total cholesterol, HDL-cholesterol, total protein, and globulin were decreased in the low-energy group without emulsifier but they were increased by emulsifier supplementation (P = 0.008, P = 0.005, P = 0.037, and P = 0.005, respectively). It could be concluded that the mixture of emulsifier supplementation to low-energy diets enhanced fat utilization and resulted in positive effects on the growth performance, nutrient utilization, lipid peroxidation, and modified plasma lipid profiles in broilers. Getting such benefits in broilers is a necessity to reduce the feed cost and consequently the price of the product, which will lead to improved welfare of mankind.

The Influence of Dietary Chicken Egg Lysozyme on the Growth Performance, Blood Health, and Resistance Against Escherichia coli in the Growing Rabbits' Cecum

The dietary chicken egg lysozyme (LZM) at different concentrations was tested on the growth performance, blood health, and resistance against Escherichia coli of growing rabbits. A total number of 48 rabbits averaged 611.25 g (5 weeks of age) of APRI line-rabbits (Egyptian developed line) were allocated into four treatments (three replicates and each contained four rabbits) of 5-week weaning APRI rabbits. The first group was fed a basal diet without LZM supplementation and served as a control group, whereas the remaining groups of rabbits were fed a basal diet supplemented with LZM at 50, 100, and 200 mg/kg diet, respectively, for 8 weeks. The obtained results revealed that rabbits fed the basal diet supplemented with different concentrations of LZM linearly (P < 0.05) displayed improved growth performance and reduced feed intake and FCR. The best result was for rabbits fed a 200 mg per kg diet supplemented with LZM, followed by a 100 mg per kg diet. The total count of Escherichia coli and Clostridium count was linearly (P < 0.05) decreased by adding LZM at 100 and 200 mg/kg in the diets compared to the control groups. In contrast, total bacterial count and the total count of Lactobacilli had increased considerably by increasing LZM at different levels relative to the control groups. The LZM supplementation linearly (P < 0.05) increased hematological parameters (RBCs, PCV, Hb, and WBCs) together with an increase in lymphocyte count compared to the control group. The total protein and globulin concentrations were significantly (P < 0.05) increased by feeding with LZM. On the other hand, ALT, AST, urea, and creatinine were significantly (P < 0.05) decreased by increasing LZM supplementation. It could be concluded that supplementation of the rabbit's diet with chicken egg LZM was able to improve the growth performance and hematological and serum biochemical parameters compared with the control group. Therefore, LZM is required at the rate of the hobx100-200 mg/kg diet as a potential feed additive and a friendly alternative for antibiotics in rabbit feed.

Central NPY-Y5 sub-receptor partially functions as a mediator of NPY-induced hypothermia and affords thermotolerance in heat-exposed fasted chicks

Exposure of chicks to a high ambient temperature (HT) has previously been shown to increase neuropeptide Y (NPY) mRNA expression in the brain. Furthermore, it was found that NPY has anti‐stress functions in heat‐exposed fasted chicks. The aim of the study was to reveal the role of central administration of NPY on thermotolerance ability and the induction of heat‐shock protein (HSP) and NPY sub‐receptors (NPYSRs) in fasted chicks with the contribution of plasma metabolite changes. Six‐ or seven‐day‐old chicks were centrally injected with 0 or 375 pmol of NPY and exposed to either HT (35 ± 1°C) or control thermoneutral temperature (CT: 30 ± 1°C) for 60 min while fasted. NPY reduced body temperature under both CT and HT. NPY enhanced the brain mRNA expression of HSP‐70 and ‐90, as well as of NPYSRs‐Y5, ‐Y6, and ‐Y7, but not ‐Y1, ‐Y2, and ‐Y4, under CT and HT. A coinjection of an NPYSR‐Y5 antagonist (CGP71683) and NPY (375 pmol) attenuated the NPY‐induced hypothermia. Furthermore, central NPY decreased plasma glucose and triacylglycerol under CT and HT and kept plasma corticosterone and epinephrine lower under HT. NPY increased plasma taurine and anserine concentrations. In conclusion, brain NPYSR‐Y5 partially afforded protective thermotolerance in heat‐exposed fasted chicks. The NPY‐mediated reduction in plasma glucose and stress hormone levels and the increase in free amino acids in plasma further suggest that NPY might potentially play a role in minimizing heat stress in fasted chicks.