Understanding the Effect of Compound Probiotics on the Health of Rabbits and Its Mechanisms Through Metagenomics

In this study, we investigated the effects of probiotics on growth performance, immunity, intestinal flora, and antioxidant capacity of rabbits. Three hundred New Zealand white rabbits were randomly divided into four groups. Groups A, B, C, and D were the lactobacillus group, compound probiotic group, control group, and antibiotic group, respectively. The results showed compared with the control group, the average weight of groups A, B, and D increased by 14.88%, 12.33%, and 11.97%, respectively. Moreover, the index of immune organs and the IgG and IgM in serum of group B were significantly increased (P < 0.05). Meanwhile, the activities of superoxide dismutase (SOD) in group B and catalase (CAT) in group A were significantly increased (P < 0.05). At week 5, the contents of rabbit cecum were taken for metagenome sequencing, and the results showed probiotics increased the relative abundance of Akkermansia, and decreased the relative abundance of Bacteroides. According to the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, we found probiotics could enrich metabolic pathways such as carbohydrates, amino acids, and lipids. According to the Comprehensive Antibiotic Resistance Database (CARD), we found antibiotic resistance ontology (ARO) in cecum mainly included β-lactamases, macrolide 2'-phosphotransferase II, and plasmid-mediated quinolone resistance protein. Among them, there were 1964, 2105, and 1982 types of ARO in group B, group D, and groups A and C, respectively. These results showed probiotics played a beneficial role in maintaining or enhancing the health and growth of rabbits and could replace antibiotics under certain feeding conditions.

Age features and reference intervals for the concentrations of some essential and toxic elements in laying hens

Background and Aim: Micronutrient imbalances pose a severe threat to the health and productivity of livestock and poultry. In this regard, a further stage in feeding science development will control and optimize the intake of mineral substances, including determining the elemental composition in some biosubstrates. One of these biosubstrates can be a feather. However, the amount of available information on the content of trace elements in laying hens is limited, complicating the laboratory data interpretation. Therefore, this study established reference intervals for the concentrations of the main essential and toxic elements in laying hens in different periods of ontogenesis. Materials and Methods: The study was conducted on clinically healthy Hisex Brown laying hens at the age of 10 (n=150), 30 (n=150), 120 (n=150), 150 (n=150), and 210 (n=150) days. All examined birds were born and raised on the territory of the South Ural biogeochemical province of Russia. The sampling of feathers was carried out by plucking the flight feathers of the wing. Inductively coupled plasma dynamic reaction cell mass spectrometry determined the elemental composition of the feather according to 25 parameters. Results: The results showed that at the minimum age (10 days), the highest concentrations of chemical elements were observed in laying hens. Subsequently, as they grew older, in the period from the 30th to the 120th day, there was a significant decrease in these indicators. Later, from the 120th to the 150th day, a statistically significant increase in concentrations was replaced. Little growth and relative concentration stability were observed in the last part of the experiment (150-210 days). Chemical element concentrations in feathers were computed in reference ranges for each age group. Conclusion: The calculated ranges of chemical element concentrations in laying hens can be used to compile norms for their content in the body; however, it is worth noting that these ranges can vary depending on the biogeochemical province of breeding and the bird's age.

Evaluating productive performance, meat quality and oxidation products of Italian White breed rabbits under free-range and cage rearing system

Objective

Free-range systems have been increasingly available to the consumer due to increased demand for more sustainable meat-products. In the current study, the effect of free-range (FR) and cage system (CS) was explored on growth performance, meat quality and oxidation products in Italian White breed rabbits during the growing-fattening phase (5 to 13 weeks of age).

Methods

Forty rabbits were randomly allotted to two treatment groups according to the rearing system, and each treatment group was replicated five times with four subjects in each replicate (20 rabbits per treatment-group). All rabbits fed the same diet as pelleted, and under FR system, no additional feeds were available to animals.

Results

Rearing system had significant effect on rabbit growth performance, where CS group resulted in higher final body weight (p<0.045) and gain (p<0.029) and better feed efficiency (p<0.025) compared to FR rabbits. Most carcass traits were not affected by rearing system; however, a reduction of abdominal fat content (p<0.015) and meat lipids (p<0.034) was observed in FR rabbits. Rearing system had no effects on meat fatty acid profile, whereas meat from FR rabbits resulted less susceptible to lipid and protein oxidation compared to caged animals.

Conclusion

In overall, FR system could be suggested as a substitute for conventional caged system because of FR system preserved rabbit meat from oxidation.

Study on growth enhancement and the protective effects of dietary prebiotic inulin on immunity responses of rainbow trout (Oncorhynchus mykiss) fry infected with Aeromonas hydrophila

The present study evaluated the effects of dietary inulin on growth performance, body composition, serum, biochemical, and mucus immune factors; as well as innate immune responses of rainbow trout fry challenged with Aeromonas hydrophila. Four diets were prepared using a commercially available fish feed as a basal diet and different levels of prebiotic inulin incorporation; 0 (control), 1, 2, and 3%; referred to as C, T1, T2, and T3, respectively. The findings of the 60-day feeding trial showed that inulin inclusion affected final weight, food conversion rate (FCR), and specific growth rate (SGR) compared to that of the control group (P < 0.05), in which the lowest FCR was observed in T3. Body composition analysis revealed that inulin significantly increased protein content and decreased lipid levels, especially in the T1 and T2 groups. The lowest ash level was noticed in T2 (P < 0.05). Blood total protein, albumin, globulin, cholesterol, and glucose were not affected by inulin supplementation (P > 0.05). Analysis of humoral immune responses showed that the inulin supplements significantly increased lysozyme and complement activities (P < 0.05), as well as higher red blood cell count (RBC) and hemoglobin (Hb) in fish, fed 2% inulin, while no significant differences were observed among other treatments (P > 0.05). The mucosal parameters; including lysozyme, alkaline phosphatase (excluding ACH50); protease activities; and total immunoglobulin (IgM) improved significantly (P < 0.05), particularly in the T2 group. The T2 group also demonstrated the highest survival rate among all groups. The present findings indicate that dietary administration of inulin promotes growth and biochemical parameters, as well as serum immunity and mucosal immune responses of rainbow trout, in which a 2% inclusion produced the best results.

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 dietary fennel (Foeniculum vulgare Mill.) seed powder supplementation on growth performance, nutrient digestibility, small intestinal morphology, and carcass traits of broilers

Background

With the increasing demands in livestock and poultry breeding and the growing number of food-borne diseases, it is necessary to practice food safety and develop strategies to produce healthy livestock. Fennel (Foeniculum vulgare Mill.) has been used as an additive in poultry production by some researchers, but there are few studies on the systemic beneficial effects of dietary fennel seed powder supplementation on broilers. Therefore, this study aimed to investigate the effect of dietary fennel seed powder supplementation on feed intake, the apparent metabolic rate of nutrients, intestinal morphology, and carcass traits in Cobb broilers.

Methods

A single-factor experimental design was used. In total, 160 1-day-old Cobb broiler chicks were randomly assigned to four treatments, with four replicates each (n = 10/replicate). Broilers in the control (CN) group were fed a basal diet without fennel seed powder, and broilers in the treatment groups were fed a basal diet supplemented with 0.15% (LF), 0.30% (MF), or 0.45% (HF) fennel seed powder, respectively. Feeding trials lasted for 42 days under the conditions of ad libitum access to feed and water, and 24-h illumination. During the third and sixth weeks, digestive and metabolic assays were carried out. When the broilers were 42 days old, one chicken with a weight close to the average was selected from each repetition, euthanized by an intravenous injection of 5% sodium pentobarbital, and carcass traits were measured and intestinal samples were collected for morphological assessment.

Results

There was no significant difference in growth performance of broilers (P > 0.05). The breast muscle percentage, fat width and fat width index, breast muscle area, and breast muscle area index of broilers in the LF group were higher than those in other groups (P < 0.05). Jejunum weight and length were higher in MF than in CN and LF broilers (P < 0.05). Additionally, duodenal villi height, ileal villi height, and ileal wall thickness were higher in MF than in CN broilers (P < 0.05). There were no significant differences in nutrient utilization among all groups (P > 0.05), except that the ash apparent metabolic rate in MF broilers at 21 days of age was higher than that in LF broilers (P < 0.05). In conclusion, dietary supplementation with a moderate concentration of fennel affects carcass performance, and intestinal morphology, and promotes the growth and development of broilers.

Effect of Inclusion of Degraded and Non-Degraded Date Pits in Broilers' Diet on their Intestinal Microbiota and Growth Performance

Simple Summary

In developing countries, most of the feedstuffs for animal nutrition are imported. Therefore, great attention has been focused on the use of agro-industrial by-products as feedstuffs to improve the feeding value of animal nutrition. These improvements can be induced by different means, including feed additive supplements, such as enzymes, probiotics, prebiotics, and organic acids. Other factors can also induce enhancement such as grinding, autoclaving, pelleting, and solid-state degradation by cellulolytic fungi. These methods aim to enhance the digestion of complex carbohydrates and decrease anti-nutritional constituents. In this study, the impact of non-degraded date pits (NDDP) and degraded date pits (DDP) using the cellulolytic fungus Trichoderma reesei in broiler’s diets on the gut bacterial growth and growth performance was investigated. It was found that when DDP are present at a rate of 10% of the broilers’ diet, it boosted gut health by increasing prebiotic production, thus serving as a growth promoter in broilers’ nutrition.

Abstract

The current study aims to assess the effect of non-degraded date pits (NDDP) and degraded date pits (DDP) in broilers’ diets on gut microbiota and growth performance. The degradation of date pits (DP) occurred via the cellulolytic fungus Trichoderma reesei by a solid-state degradation procedure. One-day-old Brazilian broilers were allocated into six dietary groups: (1) maize–soy diet, (2) maize–soy diet with oxytetracycline (20%, 50 g 100 kg⁻¹), (3) maize–soy diet with 5% NDDP, (4) maize–soy diet with 10% NDDP, (5) maize–soy diet with 5% DDP, and (6) maize–soy diet with 10% DDP. At the end of the trial, the total count of bacteria was significantly (p < 0.05) less in broilers fed 10% DDP diet (treatment 6) compared with the control group (treatment 1). In addition, DDP and oxytetracycline control diets have a similar diminishing effect on total bacterial counts and the populations of Salmonella, Campylobacter, Shigella spp., and Escherichia coli. Over 35 days of trial, weight gains were similar among the six dietary groups. Our results showed that DDP and control diets have a similar effect on growth performance. The feed conversion ratio (FCR) was poorer in broilers fed NDDP diets than other treatments. The European Production Efficiency Index (EPEI) was greater with 5% and 10% DDP than those fed NDDP at the same levels, with no significant variance from the control and antibiotic-supplemented diet (treatment 2). Overall, it can be suggested that maintaining 10% of DDP can partly replace dietary maize while also serves as a gut health enhancer and thus a growth promoter in the diet for broilers.

Growth, immunity, relative gene expression, carcass traits and economic efficiency of two rabbit breeds fed prebiotic supplemented diets

The current study designed to evaluate the effect of oligosaccharide supplemented diets on growth performance, histomorphometric changes, economic efficiency and genetic expression of some growth and immunity-relative genes. One hundred and twenty weaned male rabbits, six weeks of age of two breeds (NZW and APPRI) were randomly allocated into six equal groups; the first supplemented with 0.3% Mannan-oligosaccharide (MOS), the second supplemented with 0.05% Isomalto-oligosaccharide (IMO) and the third considered a control group. Each group contained ten equal replicates. The highest Final body weight and feed consumption were recorded in MOS and IMO groups compared with control. Fortified feed diet with IMO significantly increased duodenal villi area and length than MOS and control groups. At the same time, Spleen white bulb area and length were significantly higher in MOS and IMO than control. Supplementation of MOS and IMO significantly improved carcass traits, economic efficiency and induced certain modifications in some major key genes involved in the regulation of nutrients metabolism, immunity and growth in different tissues. In conclusion, dietary supplementation of MOS and IMO had a desirable positive impact on productive and economic efficiency in the rabbit.

Early Introduction of Solid Feeds: Ingestion Level Matters More Than Prebiotic Supplementation for Shaping Gut Microbiota

Early introduction of a nutritional substrate is a promising biomimetic strategy for controlling the implantation of the microbiota and preserving the health of young animals. In this study, we provided experimental solid substrate in a gel form to stimulate suckling rabbits' intake and to investigate its effects on microbiota implantation and colonization. All the rabbits had access to solid feed outside the nest as of 15 days of age. Except for the control group, rabbits were offered starter feed gels inside the nests from 3 to 18 days of age. These gels were either free of additives (AF_GEL) or contained 4% of fructo-oligosaccharides (FOS_GEL) or 4% of mannan-oligosaccharides and β-glucans mixtures (MOS_GEL). The cecal content of 160 rabbits was sampled at 18, 29, 38, and 57 days of age and analyzed using 16S rRNA gene sequencing. Pups consumed an average of 3.95 ± 1.07 g of starter feed gel with a higher intake when it was supplemented with fructo-oligosaccharides (+1.2 g; P < 0.05). Starter feed gel consumption increased the ensuing intake of pellets (+17 g from 15 to 21 days; P < 0.05). Alpha-diversity indexes were similar between groups and prebiotic supplementation did not induce a clear shift in microbiota pattern. Conversely, when considering rabbits that consumed more starter feed, the highest proportions of bacteria with plant-degrading abilities, such as species from the Lachnospiraceae and Ruminococcaceae families, were observed at 18 days of age. However, fermentative activities were not affected by starter feed intake at 29, 38, and 57 days of age. By providing comprehensive results on the regulation of microbial community structure at the onset of solid feed intake, this research paves the way for further studies on digestive ecosystem maturation.

Impact of Prebiotics and Synbiotics Administered in ovo on the Immune Response against Experimental Antigens in Chicken Broilers

Simple Summary

The immune system of chickens matures in the course of embryonic development. Early in ovo supplementation with bioactive substances leads to the long-term maintenance of a high level of intestine bifidobacteria, reduces the number of detrimental microorganisms in the gut, modulates the central and peripheral lymphatic organ development in broilers, and stimulates gut-associated lymphoid tissues (GALT) development after hatching. In this investigation, we studied whether the early in ovo application (at the 12th day of embryo incubation) of selected bioactives (prebiotics and synbiotics) influences the humoral immune response against experimental antigens, and the delayed-type hypersensitivity (DTH) skin reaction to experimental mitogen. This study demonstrated that the in ovo application of bioactives did not significantly influence the humoral immune response against T-dependent and T-independent model antigens. Prebiotics in chickens immunized with T-dependent antigen (SRBC) protected them from a retarded rise of the IgG concentration. Bioactives reduced the mortality of birds, markedly with inulin (−6.4%), and the DTH reaction to phytohemagglutinin on the 7^th and 21^st day after hatching.

Abstract

The effect of the in ovo application of selected prebiotics and synbiotics on the humoral immune response against T-dependent (SRBC) and T-independent (dextran) antigens and delayed-type hypersensitivity (DTH) to phytohemagglutinin was studied. On the 12th day of incubation, 800 eggs (Ross 308) were divided into five groups and injected into the egg air chamber with prebiotic inulin (Pre1), Bi²tos (Pre2), a synbiotic composed of inulin and Lactococcus lactis subsp. lactis IBB SL1 (Syn1), a synbiotic composed of Bi²tos and L. lactis subsp. cremoris IBB SC1 (Syn2), and physiological saline (control group; C). The chickens were immunized twice at the 7th and 21st day of life with SRBC and dextran. A DTH test was performed on the 7th, 21st, and 35th day. The application of prebiotics and synbiotics had no significant effect on the humoral immune response. SRBC-immunized in ovo Pre1- and Pre2-treated chickens showed significantly higher serum IgG levels than the control. A significant effect on the DTH reaction was detected on the 7th (Pre1 < C) and 21st (Pre2 > Syn2) day. However; Bi²tos may transiently stimulate the cellular immune response on the 21st day. It may be concluded that the application of inulin in an egg air chamber on the 12th day of incubation may stimulate the secondary immune response. The inulin-treated group exhibited a lower mortality rate than the control group.

Effects of Fennel Seed Powder Supplementation on Growth Performance, Carcass Characteristics, Meat Quality, and Economic Efficiency of Broilers under Thermoneutral and Chronic Heat Stress Conditions

Simple Summary

Nowadays, great attention has been given to phytogenic products as a growth enhancer due to their safety and eco-friendly influences on animal nutrition. Thus, this investigation looked at the use of fennel seed powder at 0, 1.6, and 3.2% as a dietary additive on the performance, carcass traits, meat quality, and efficiency of the production of broiler chickens raised under thermoneutral and chronic heat stress conditions. In essence, 3.2% fennel seed powder in the diet of broilers enhanced the growth rate under chronic heat stress and decreased breast meat redness and temperature, suggesting that 3.2% fennel seed could be used as an agent for enhancing the broiler’s tolerance during chronic heat stress (CHS) condition from 19 to 41 days of age.

Abstract

Nowadays, phytogenic products have received great attention as a growth promoter due to their safety and environmentally friendly effect as a replacement for classical growth promoters such as antibiotics in animal nutrition. Thus, this research seeks the possibility of using fennel seed powder (FSP) as a dietary additive from 19 to 41 days of age on productive performance, carcass traits, meat quality, and production efficiency of broiler chickens raised under thermoneutral and chronic heat stress conditions. Thus, 216 one-day-old Ross-308 broiler chicks were divided into two equal groups. The first group was placed in an independent temperature-controlled room at 23 ± 2 °C. The broiler chicks from the second group were placed in a heat-stressed room and exposed to chronic heat stress conditions (32 ± 2 °C) for seven hours per day from 8 a.m. to 3 p.m. The experimental design was 2 × 3 factorial including two environmental temperatures (thermoneutral vs chronic heat stress) and three experimental diets that contained 0, 1.6, and 3.2% FSP. The chickens were randomly assigned to 18-floor pens per room temperature, representing six replicates per treatment and six birds per replicate. The results showed that dietary fennel seed powder during days 19–41 of age enhanced the growth rate of broiler chickens and improved breast meat redness and reduced temperature under chronic heat stress. In conclusion, 3.2% of fennel seed powder could be used as an agent for enhancing the broiler’s tolerance during chronic heat stress condition from 19 to 41 days of age. Moreover, it is necessary to study in further detail the nitrite and nitrate contents in FSP and their impacts on muscle redness (a*) as well as muscle temperature.

Supplementation with Fish Oil Improves Meat Fatty Acid Profile although Impairs Growth Performance of Early Weaned Rabbits

Our objective was to analyze the influence of replacing lard (control) with fish oil (FO) rich in long-chain n-3 polyunsaturated fatty acids in the diet of rabbits weaned at 25 days of age on their growth performance, meat quality, cecal fermentation, and ileal morphology. Twenty-four litters (12 control and 12 FO) of nine kits each were fed the experimental diets from weaning (25 days) until slaughter at 60 days of age. Half of the litters (six per diet) were used to monitor productive performance, carcass characteristics, and ileal morphology, and cecal fermentation was assessed in the rest of litters. Diet had no influence on feed intake, meat color, and pH or cecal fermentation, but FO-fed rabbits had lower (p ≤ 0.049) average daily gain, chilled carcass weight, and perirenal fat than control rabbits. Fish oil inclusion in the diet resulted in lower morbidity (5.56% vs. 20.4%; p = 0.019) and a healthier fatty acid profile with lower (p < 0.001) n-6/n-3 ratios in both muscle and perirenal fat. In summary, the inclusion of FO in the diet of early weaned rabbits improved the fatty acid profile of rabbit meat and fat and decreased the morbidity, but growth performance was slightly reduced.

Evaluation of the carryover effect of antibiotic, bee pollen and propolis on growth performance, carcass traits and splenic and hepatic histology of growing rabbits

Sixty-four nulliparous female rabbits were distributed among eight groups (eight animals/group). Group one was the unsupplemented control group; the other seven groups were supplemented with zinc bacitracin (ZnB) at 100 mg, or bee pollen (BP) and/or propolis (Pro) at 150 and 300 mg in a capsulated form, three times a week, day after day, continuously all over the experimental period. The experiment was run for eight parties; at each parity, 28 kids of each doe group (a total of 224 rabbits) were divided into two subgroups weaned, respectively, at 24 and 30 days of age. Thus, for each parity, there were 16 groups (eight does treatments × two weaning age, 14 rabbits per group). The growing rabbits fed the standard diets without supplements. The growth performance, the carcass traits, the liver and the spleen histology of rabbits were checked up to 90 days of age to find possible carryover effects of the supplements. The supplements had no significant effect on most of the growth performance at 90 days of age, but BP150 and BP+Pro300 increased the growth rate in comparison with ZnB group. The liver weight in the control, BP300 and Pro300 groups was higher than the ZnB one. The spleen weight was higher in the groups ZnB, BP150, Pro300 and BP+Pro300, followed by the control, BP300 and BP+Pro150 and thus Pro150. The heart % in the BP150 and Pro300 groups was higher than ZnB and BP+Pro150 groups. A lymphoid hyperplasia of splenic white pulp was observed in the BP+Pro groups, while propolis alone showed a mild activation of lymphobiosis. The Pro and BP groups showed the same picture of the control group exhibiting a hydropic degeneration of mostly hepatic cells, while the ZnB group exhibited adverse effect on the bile ducts featuring portal periductal inflammatory cells infiltration with epithelial hyperplasia reflecting chronic cholangitis.

Semen quality, antioxidant status and reproductive performance of rabbits bucks fed milk thistle seeds and rosemary leaves

The study aimed to investigate the effects of milk thistle seeds (MTS) and rosemary leaves (RL) both at 5 and 10g/kg diet on reproductive performance, semen quality and blood metabolites of rabbit bucks. A total of 35 rabbit bucks were randomly distributed into five experimental groups (7 bucks/group). All the groups were fed the same basal diet. The 1st group (control) did not have MTS and RL in its basal diet. The 2nd and 3rd groups were supplemented with MTS at 5 and 10g/kg, respectively. The 4th and 5th groups were fed the basal diet supplemented with RL at 5 and 10g/kg, respectively. The sperm concentration (SC), total sperm output (TSO), live sperm (LS), total live sperm (TLS) and total motile sperm (TMS) were significantly greater in the bucks fed MTS at 10 and RL at 5g/kg diet than the control group. Bucks fed MTS at 10g/kg diet had higher fertility than the control. Also, RL 5g/kg group showed higher testosterone and fertility than the control, but the MTS 10g/kg group showed the highest value for both parameters. In conclusion, MTS and RL at 10 and 5g/kg, respectively, significantly improved the semen quality and the fertility and MTS also increased the economic efficiency of rabbit bucks.

Effect of dietary mannan-oligosaccharides on some blood biochemical, haematological parameters and carcass traits in purebred New Zealand White and crossbred rabbits

This study examined the effect of dietary treatments containing mannan-oligosaccharides (MOS) on some blood biochemical, haematological parameters and carcass traits of 60 weaned purebred New Zealand White (NZW) and New Zealand White × Rex (NZW × RX) crossbred rabbits. They were assigned to a 2 × 3 factorial arrangement (two genetic groups; and three dietary treatments of zero, 0.5 or 1.0 g MOS/kg of diet). Blood samples have been collected at slaughter at 10 weeks of age. Significant differences were observed among dietary treatments for all biochemical and haematological parameters with the exception of triglycerides. There was a genetic group and dietary treatment interaction for albumen (P < 0.001), cholesterol (P = 0.002), red blood cell count (RBC) (P = 0.007), haemoglobin (Hb) concentration (P = 0.009) and haematocrit % (P < 0.001) observed. Rabbits from the NZW × RX genetic group fed a diet with 1.0 g/kg MOS had the highest plasma cholesterol level (0.97 ± 0.012 mmol/L), whereas the lowest level (0.89 ± 0.012 mmol/L) was detected in rabbits from the NZW × RX genetic group fed the Control diet. Rabbits from the NZW genetic group fed the diet with 1.0 g/kg MOS had the highest RBC (4.27 ± 0.083 × 106/mm3) whereas rabbits from the same genetic group fed the diet with 0.5 g/kg MOS had the highest Hb concentration (11.43 ± 0.097 g/dL) and haematocrit (30.29 ± 0.163%). Some carcass traits such as liveweight, hot and reference carcass weight (P < 0.001), percentage of periscapular, and perirenal fat relative to reference carcass weight (P < 0.05) were significantly affected by the dietary MOS supplementation. In conclusion, MOS supplementation in the diet, especially 1.0 g/kg, improved immunity, health indicators in the blood, liveweights and carcass weights of rabbits without any harmful effects on the other carcass traits. Furthermore, purebred NZW and NZW × RX crossbred rabbits showed relatively similar performance for all traits of interest. A significant interaction between genetic group and dietary supplementation of MOS was shown for albumen, cholesterol, RBC and haematocrit %.

Productive and reproductive performance of rabbits does as affected by bee pollen and/or propolis, inulin and/or mannan-oligosaccharides

<p>The aim of the paper was to compare the effect of prebiotics (inulin and/or mannan-oligosaccharides, MOS) and bee products (bee pollen and/or propolis) on productive and reproductive performance of rabbit does. Seventy nulliparous V-line female rabbits were distributed among 7 groups. The groups were fed the same diet and received no supplements (control group), natural molecules (bee pollen and/or propolis) at 200 mg/kg body weight (BW) or prebiotics (inulin and/or MOS) at 35 mg/kg BW. Productive, reproductive, biochemical and haematological traits were investigated. Bee pollen with propolis significantly increased body weight gain of does 1 wk after mating (3.53%), decreased feed intake (4.49%) and caused larger litter size (39.4%), heavier body weight of litter (17.7%), a greater number of kits born alive (48.7%), higher weight of kits (87.81%) at 28 d of age, higher milk yield (43.6%) and more favourable milk conversion ratio (31.6%). Moreover, bee pollen with propolis had significantly increased plasma total protein (43.1%), albumin (45.7%), globulin (41.0) and progesterone (60.5%), and had a significantly decreased plasma cholesterol (31.1%), aspartate aminotransferase/alanine aminotransferase ratio (20.3%) compared to the control group. Does treated with growth promoters had significantly fewer services per conception (22%) and greater fertility rate (21%) compared to the control group. Inulin with or without MOS significantly increased plasma glucose (49.9 and 50%, respectively) and feed cost (90.2%) compared to the control group. Supplementation of MOS or bee pollen with or without propolis had significantly greater relative economic efficiency (61.9, 55.1 and 27.1%, respectively) than the control group. MOS and bee pollen with or without propolis are able to improve productive and reproductive performance and economic efficiency of rabbit does in comparison to the unsupplemented group.</p>

Effect of zinc bacitracin and phytase on growth performance, nutrient digestibility, carcass and meat traits of broilers

A total of 336 one-day-old Hubbard broiler chickens were randomly distributed among 8 groups, each containing six replicates (7 chickens/replicate). From 1 to 40 days of age, the groups fed the same starter, grower and finisher diets. The control group was unsupplemented; zinc bacitracin (ZnB) group received the antibiotic at 0.5 g/kg; fungal phytase (FP) groups received 250, 500 and 1000 U/kg diet of Aspergillus niger phytase (FP_250, FP_500 and FP_1000 groups), respectively; bacterial phyatse (BP) groups received 250, 500 and 1000 U/kg diet of Escherichia coli phytase (BP_250EP, BP_500EP and BP_1000EP groups) respectively. Considering the whole experimental period, body weight gain was unaffected by ZnB and different concentrations of bacterial and fungal phytase; however, the feed conversion ratio of the group fed a diet supplemented with 500 U of BP was better (p < 0.01) than those fed with a diet supplemented with 500 U of FP. BP_250 group had a higher (p < 0.05) apparent digestibility of ether extract compared to FP_250 group. In conclusion, bacterial phytase at 500 U may enhance performance of broiler chickens fed during days 1-40 of age and yield similar growth performance and economic efficiency to those of eB-supplemented groups.

Use of food waste as fish feeds: effects of prebiotic fibers (inulin and mannanoligosaccharide) on growth and non-specific immunity of grass carp (Ctenopharyngodon idella)

The effects of inulin and mannanoligosaccharide (MOS) on the growth performance and non-specific immunity of grass carp were studied. Two doses of prebiotic fiber with 0.2 or 2% of the fibers are being mixed into fish feed pellets. Fish growth as well as selected non-specific immune parameters of grass carp were tested in a feeding trial, which lasted for 8 weeks. Fish was fed at 2.5% body mass per day. INU02, INU2, and MOS2 significantly improved relative weight gain, specific growth rate, protein efficiency ratio, and food conversion ratio of grass carp fed with food waste-based diet. In terms of non-specific immune response, grass carp showed significant improvement in all three tested parameters (total serum immunoglobin, bactericidal activity, and anti-protease activity). Adding 2% of inulin (INU2) into food waste diets seemed to be more preferable than other supplemented experimental diets (INU02, MOS02, MOS2), as it could promote growth of grass carp as well as improving the non-specific immune systems of grass carp.