Decreased Feed Conversion Ratio Research Articles

Dietary honokiol supplementation improves antioxidant capacity, enhances intestinal health, and modulates cecal microbial composition and function of broiler chickens

Honokiol is a multifunctional polyphenol present in Magnolia officinalis. The effects of honokiol as a supplement in broiler chicken diets, and the underlying mechanisms, remain unclear. Therefore, the aim of the present study was to investigate the effects of honokiol on the growth performance, antioxidant capacity, and intestinal histomorphology of broiler chickens and to explore the underlying mechanisms. In total, 240 one-day-old broilers were randomly allocated to 5 dietary treatments, with 6 replicate pens and 8 birds per pen. Birds were fed a basal diet supplemented with 0 (blank control, BC), 100, 200, or 400 mg/kg honokiol (H100, H200, and H400), or 200 mg/kg bacitracin zinc (PC) for 42 d. The results showed that H200 and H400 increased body weight gain (BWG) and decreased feed conversion ratio (FCR) during the starter period (P < 0.05). H100 and H200 increased total superoxide dismutase (T-SOD) activity in the serum and decreased malondialdehyde (MDA) amount in the jejunum on d 42 (P < 0.05). Moreover, H100 increased villus height-to-crypt depth ratio in both the jejunum and ileum on d 21 (P < 0.05). PCR analysis showed that honokiol upregulated intestinal expression of glutathione peroxidase (GSH-Px) and downregulated intestinal expression of inducible nitric oxide synthase (iNOS) on d 42 (P < 0.05). The Shannon index, which represents the microbial alpha diversity, was reduced for the PC, H200, and H400 groups. Notably, honokiol treatment altered the cecal microbial community structure and promoted the enrichment of several bacteria, including Firmicutes and Lactobacillus. Higher production of short-chain fatty acids was observed in the cecal digesta of H100 birds, accompanied by an enriched glycolysis/gluconeogenesis pathway, according to the functional prediction of the cecal microbiota. This study provides evidence that honokiol improves growth performance, antioxidant capacity, and intestinal health of broiler chickens, possibly by manipulating the composition and function of the microbial community.

The baicalein amorphous solid dispersion to enhance the dissolution and bioavailability and effects on growth performance, meat quality, antioxidant capacity and intestinal flora in Taihang chickens

Baicalein (BAI) is a natural flavonoid with antioxidant, antitumor and antibacterial properties. However, the bioavailability of BAI was limited due to low solubility. This study aims to improve the solubility of BAI through the amorphous solid dispersion (ASD) and evaluate changes in its pharmacokinetics and pharmacodynamics in Taihang chickens. Polyethylene caprolactam-polyvinyl acetate-polyethylene glycol grafted copolymer (Soluplus) was chosen as the carrier, and ASD was prepared by rotary evaporation and was characterized by powder X-ray diffractions (PXRD), differential scanning calorimetry (DSC) and fourier transform infrared spectroscopy (FT-IR). In vitro dissolution assays were used to screen the optimal ratio of drug to carrier, in vivo pharmacokinetic assays were conducted to investigate the promoting effect on the absorption. In addition, the effects of ASD on the growth performance, meat quality, antioxidant capacity and intestinal flora were investigated. ASD (1:9 and 2:8) did not exhibit crystal diffraction peaks of BAI in PXRD or endothermic peaks in DSC, indicating the successful preparation of ASD. The results of in vitro dissolution assay showed that the cumulative dissolution rate of ASD (2:8) within 600 min was 52.67%, which was 7.84-fold higher than BAI. The pharmacokinetic results showed that the peak concentration (Cmax) and the area under the drug-time curve (AUC0∼24) of ASD (2:8) was (5.20 ± 0.82) μg/mL and (17.03 ± 0.67) μg·h/mL, which was 1.91 and 2.64-fold higher than BAI, respectively. Dietary supplementation of BAI and ASD could increase average daily gain (ADG), while decrease feed conversion ratio (FCR), but there was no significant difference (P > 0.05). The drip loss of BAIASD group was lower than BAI group (P < 0.05). In addition, the antioxidant capacity of Taihang chickens were enhanced, the diversity and the abundance of beneficial bacteria was improved. Results of BAI upon the dietary supplementation tested in Taihang chickens, after preparation of ASD, indicating a superior enhancement effect in growth performance, meat quality, antioxidant capacity and intestinal flora due to an improved solubility and optimized bioavailability.

The impact of selenium yeast and vitamin E in blood profile and egg production of laying hens at the end of egg production period

This study investigated the effects of selenium yeast and vitamin E supplementation on hematological parameters, egg production, and quality in laying hens aged beyond 94 weeks. The experiment adhered to ethical regulations and employed a Completely Randomized Design Dietary treatments included a basal diet (T0), or a basal diet supplemented with 0.450 mg selenium yeast and 100 mg vitamin E (T1), 0.675 mg selenium yeast and 100 mg vitamin E (T2), 0.450 mg selenium yeast and 200 mg vitamin E (T3), 0.675 mg selenium yeast and 200 mg vitamin E per kg diet (T4). There were 125 hens divided in five treatments and five replicates that contained five hens per replicate. Hematological parameters, egg production, and egg quality were determined. The T4 treatment reduced red blood cell counts (P&lt;0.05), potentially impacting erythropoiesis. The T3 treatment increased lymphocyte content and decreased heterophil/lymphocyte ratio (P&lt;0.05), which concurs with an increase in egg weight, egg mass, and Haugh Unit, and decreased feed conversion ratio (P&lt;0.05). Thus, this study demonstrated that incorporating these supplements with the specified dosage (0.450 mg selenium yeast and 200 mg vitamin E per kg diet) in aged laying hens can enhance productivity and egg quality at the end of the production cycle.

Sodium butyrate alleviates heat stress-induced damage to morphology, anti-oxidant status, inflammatory response and barrier integrity in jejunum of broilers

To evaluate the protective effects of sodium butyrate (SB) on intestinal morphology, anti-oxidant status, inflammatory response and barrier integrity in male broilers under heat stress. A total of 180 21-d-old male Arbour Acres broilers with similar body weight were used for this 21-d experiment. Broilers were randomly allocated to three groups: CON group, basal diet and raised under 24 °C; HS group, basal diet and raised under heat stress condition (34 °C from 10:00 to 18:00 and 24 °C for the rest time); HS-SB group, basal diet with 1200 mg/kg SB and raised under heat stress condition. Compared to the HS group, SB supplementation increased average daily gain (ADG), villus height: crypt depth ratio (VH: CD), VH, glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) activity, and interleukin-10 (IL-10) level, decreased feed conversion ratio (FCR), CD, reactive oxygen species (ROS), IL-1β and tumour necrosis factor-alpha (TNF-α) level, up-regulated the mRNA expression of nuclear factor erythroid 2-related factor 2, haem oxygenase 1, GSH 1 (GPX1), SOD and CAT, down-regulated the mRNA expression of toll-like receptor 4 (TLR4), nuclear transcription factors, IL-1β, and TNF-α in jejunum of heat-stressed broilers. Furthermore, SB supplementation up-regulated the mRNA expression of occluding, claudin-1 and zona occludens-1 (ZO-1) in jejunum of heat-stressed broilers, accompanied with decreasing serum endotoxin and D-lactic acid concentration, and diamine oxidase (DAO) activity. There results suggested that SB supplementation could alleviate heat stress-induced jejunal tight junction structure dysfunction by up-regulated the expression of occluding, claudin-1 and ZO-1, presumably through alleviating oxidative stress and inflammatory response. HIGHLIGHTS Sodium butyrate alleviated heat stress-induced jejunal morphology damage. Sodium butyrate alleviated heat stress-induced jejunal oxidative damage. Sodium butyrate alleviated heat stress-induced jejunal inflammatory response. Sodium butyrate alleviated heat stress-induced tight junction structure dysfunction.

Effect of carob (Ceratonia siliqua) on growth parameters and viability of local Algerian rabbit populations (Oryctolagus cuniculus)

The objective of this study is to evaluate the effect of incorporating different levels of carob on carcass quality and the viability of the local rabbit in eastern Algeria. Carob diets with 3.5 kg/T, 5 kg/T, and 100% carob were distributed to 3 groups of kids from the local population, from weaning at 28 days to slaughter at the age of 110 days. The statistical results show the effect of using carob and also with an incorporation rate of 3.5 kg/T on the live weight of the rabbits and led to a decrease in feed conversion ratio, good feed efficiency, and feeding costs. The highest ADG (28-108 days) and final weight at 108 days are 25.82 g/day, and 1328.37 g respectively. The best performing CI was 3.32, obtained during the growing period for a rabbit weaned at 28 days (Group 1) receiving carob supplementation. As a result, the health risk index, or "HRI," was higher for rabbits in the G1 and G2 whole fattening periods (28-35 and 35-49 days, respectively), and then decreased for the remainder of the period. Mortality and morbidity measurements do not indicate any significant effect of carob use on the health status of rabbits (P &lt; 0.05).The results of this work showed that the supplementation of carob improves the growth performance and dressing yield of local rabbits.

Environmental impact of Italian pig herds as affected by farm management factors

This study aimed at evaluating the environmental impact (EI) of herds representative of the Italian heavy pig production system to investigate the EI variation associated with farm management (FM), diet formulation (DF) and animal response (AR) variables. Data originated from 8 breeding farms, which included the sows and preweaning piglets (Site1) and the post-weaned piglets (7.5–30 kg body weight – BW, Site2) and 10 growing–fattening farms, dealing with 30–170 kg BW pigs (Site3). A cradle-to-farm gate Life Cycle Assessment was used, with 1 kg BW gain (BWG) as functional unit. Impact categories were global warming (GWP), acidification (AP) and eutrophication (EP) potentials and land occupation (LO). Whole-production cycle EI (Site123, 0–170 kg BW) was obtained summing up EIs of 0–30 and 30–170 kg BW animals. Impacts were analysed with one- or two-way PERMANOVA to test the effect of FM, DF and AR variables. The Site123-related EI averaged nearly 3.1 kg CO2-eq (GWP), 50 g SO2-eq (AP), 22 g PO4-eq (EP) and 4.9 m2/y (LO) per kg BWG. Site3 contributed nearly 80% of the whole impact. Regarding Site1, GWP resulted mitigated by increasing sow productivity. Site2 EI resulted mitigated by decreasing feed conversion ratio and increasing average daily gain, whereas Site3 EI by increasing feed self-sufficiency and decreasing dietary crude protein and mortality. In perspective, given the relevance of Site3 on the whole-pig system EI, a deeper integration between the farm agronomical management and the growing–finishing pigs’ diets formulation would support the environmental sustainability of heavy pig operations.

Effects of silybin supplementation on growth performance, serum indexes and liver transcriptome of Peking ducks.

As an emerging feed additive extracted from the traditional herb milk thistle, silybin has few applications and studies in Peking ducks. The aim of this study was to explore the practical significance of silymarin application in Peking ducks and to provide more theoretical support for the application of silymarin in livestock and poultry production. A total of 156 1-day-old healthy Peking ducks were randomly divided into four groups and supplemented with 0 mg/kg (control group), 400 mg/kg (S400), 800 mg/kg (S800) and 1,600 mg/kg (S1600) of silybin in the diets at day 14, to investigate the effects of silymarin on the growth, serum indexes and liver transcriptome of Peking ducks. The whole experiment lasted until day 42, and the sample collection was scheduled to take place in the morning. A substantial inprovement in average daily gain (ADG) and a decrease in feed conversion ratio (FCR) occurred in the S1600 group on days 14-28 compared to the control group (p < 0.05). The FCRs of other additive groups in the same period showed the same results. Supplementation of diets with silybin significantly increased serum IgA levels and when 1,600 mg/kg of silybin was given, levels of TNF-α and IL-6 were also significantly decreased (p < 0.05). In addition, we observed that the S1600 group had a significantly lower (p < 0.05) glutamine transaminase and an increased (p < 0.05) T-SOD level in the S400 group (p < 0.05). Liver transcriptome sequencing showed that 71 and 258 differentially expressed genes (DEGs) were identified in the S400 and S1600 groups, respectively, compared with the control group. DEGs related to cell composition and function, antigen processing and presentation were up-regulated, while DEGs related to insulin resistance and JAK-STAT were down-regulated. Conclusively, silybin can be used as a feed additive to improve the growth performance and health status of Peking ducks.

The Effects of Dietary Silybin Supplementation on the Growth Performance and Regulation of Intestinal Oxidative Injury and Microflora Dysbiosis in Weaned Piglets.

Oxidative stress is the major incentive for intestinal dysfunction in weaned piglets, which usually leads to growth retardation or even death. Silybin has caught extensive attention due to its antioxidant properties. Herein, we investigated the effect of dietary silybin supplementation on growth performance and determined its protective effect on paraquat (PQ)-induced intestinal oxidative damage and microflora dysbiosis in weaned piglets. In trial 1, a total of one hundred twenty healthy weaned piglets were randomly assigned into five treatments with six replicate pens per treatment and four piglets per pen, where they were fed basal diets supplemented with silybin at 0, 50, 100, 200, or 400 mg/kg for 42 days. In trial 2, a total of 24 piglets were randomly allocated to two dietary treatments with 12 replicates per treatment and 1 piglet per pen: a basal diet or adding 400 mg/kg silybin to a basal diet. One-half piglets in each treatment were given an intraperitoneal injection of paraquat (4 mg/kg of body weight) or sterile saline on day 18. All piglets were euthanized on day 21 for sample collection. The results showed that dietary supplementation with 400 mg/kg silybin resulted in a lower feed conversion ratio, diarrhea incidence, and greater antioxidant capacity in weaned piglets. Dietary silybin enhanced intestinal antioxidant capacity and mitochondrial function in oxidative stress piglets induced by PQ. Silybin inhibited mitochondria-associated endogenous apoptotic procedures and then improved the intestinal barrier function and morphology of PQ-challenged piglets. Moreover, silybin improved intestinal microbiota dysbiosis induced by the PQ challenge by enriching short-chain fatty-acid-producing bacteria, which augmented the production of acetate and propionate. Collectively, these findings indicated that dietary silybin supplementation linearly decreased feed conversion ratio and reduced diarrhea incidence in normal conditions, and effectively alleviated oxidative stress-induced mitochondrial dysfunction, intestinal damage, and microflora dysbiosis in weaned piglets.

Beneficial effects of oleanolic acid on hepatopancreas oxidative stress and intestinal microbiota structure of red swamp crayfish (Procambarus clarkia)

This study aimed to evaluate the beneficial effects of oleanolic acid (OA) in the culture of red swamp crayfish (Procambarus clarkia) by investigating the impact of dietary OA on growth performance, hepatopancreas antioxidant activity, innate immunity, and intestinal microbiota structure. An eight-week feeding trial was conducted using different dietary OA concentrations: 0, 250, 500, 750, and 1000 mg·kg–1. The results revealed that the groups with 500–1000 mg·kg–1 OA exhibited increased final body weight, weight gain rate, and specific growth rate, as well as decreased feed conversion ratio compared to those in the control group (P < 0.05). Serum alanine transaminase (ALT) and aspartate transaminase (AST) activities showed a linear decrease with increasing dietary OA concentration. OA demonstrated hypolipidemic effects by reducing serum glucose, total cholesterol, triglyceride, and low-density lipoprotein cholesterol levels, while increasing serum high-density lipoprotein cholesterol levels (P < 0.05). OA500 to OA1000 groups exhibited significantly higher trypsin activity compared to that of the control, while lipase activity linearly decreased with increasing dietary OA concentration. The antioxidant capacity, as indicated by glutathione level in the hepatopancreas, showed significant differences between the OA treatment group and the control group. However, dietary OA did not significantly alter the structure of the intestinal microbiota. These findings suggest that dietary OA supplementation effectively improves the growth performance and enhanced the innate immunity of crayfish. Furthermore, OA significantly promotes the antioxidant capacity, thereby protecting the hepatopancreas from oxidative damage. The optimal dose range of dietary OA for application in crustacean culture is recommended to be between 500 and 1000 mg·kg−1.

Dietary Paenibacillus polymyxa AM20 as a new probiotic: Improving effects on IR broiler growth performance, hepatosomatic index, thyroid hormones, lipid profile, immune response, antioxidant parameters, and caecal microorganisms

The search for a natural antimicrobial agent is ongoing and critical because of the rise and rapid proliferation of antibiotic-resistant pathogenic bacteria. The current study aims to examine the effect of Paenibacillus polymyxa AM20 as an alternative antibiotic and feed additive on Indian river broiler performance, digestive enzymes, thyroid hormones, lipid profile, hepatosomatic index, immunological response, gut bacteria, and antioxidant parameters. The bacterial isolate AM20 was identified at the gene level by isolating DNA and using PCR to detect genes. Based on 16S rRNA gene sequence analysis, the bacterial isolate was identified as Paenibacillus polymyxa. One hundred twenty Indian river broilers (1-day old) were randomly divided into 4 groups of 10 chicks each, with 3 replicates. The control group was fed a basal diet only, while the other 3 were administered control diets supplemented with P. polymyxa at 3 concentrations: 0.5, 1, and 1.5 mg/kg. The findings revealed that all groups that received graded amounts of P. polymyxa increased all growth parameters throughout the study. P. polymyxa treatment at 1.5 mg/kg increased body gain by 9% compared to the control due to increased feed intake (P = 0.0001), growth rate (P = 0.0001), and decreased feed conversion ratio. Compared to the control group, P. polymyxa (1.5 mg/kg) enhanced kidney functions in chickens by reducing uric acid and creatinine levels (P = 0.0451). Compared to the control group, alanine aminotransferase and aspartate transaminase levels in the liver were significantly reduced at all P. polymyxa doses. Liver function values were highest for P. polymyxa at 1.5 mg/kg. Compared to the control group, those whose diets included P. polymyxa had significantly better blood cholesterol levels, high-density lipoprotein, low-density lipoprotein, immunological response, thyroid function, and gut microbiota. In general, broiler chickens' economic efficiency was improved by including P. polymyxa in their diet, which also improved their growth performance, carcass dressing, specific blood biochemical levels and enzymes, and the composition of the gut microbiota.

The Combined Supplementation of AZOMITE and Citric Acid Promoted the Growth, Intestinal Health, Antioxidant, and Resistance against Aeromonas hydrophila for Largemouth Bass, Micropterus salmoides.

Citric acid is an organic acid extensively used in feed industry, and AZOMITE is a hydrated aluminosilicate compound rich in rare earth elements and trace mineral elements. This study investigated the supplemental effects of AZOMITE and citric acid individual or in combination on the growth performance, intestinal microbiota, morphology, digestive enzyme activity, serum indexes, and disease resistance of juvenile largemouth bass. Six diets were designed, including the control diet (CON) and the five additive-supplemented diets with the addition of 4 or 8 g/kg citric acid (CA4, CA8), 3 g/kg AZOMITE (A3), and their combined addition as 4 g/kg citric acid + 1.5 g/kg AZOMITE) (C4A1.5) and 8 g/kg citric acid + 3 g/kg AZOMITE (C8A3). Juvenile largemouth bass with initial body weight of 22.01 ± 0.09 g were fed the six diets for 56 days. The results revealed that the combined addition of 4 g/kg citric acid and 1.5 g/kg AZOMITE (C4A1.5) increased weight gain by 7.99% (P < 0.05), and decreased feed conversion ratio by 0.07 (P < 0.05). The protein retention in the C4A1.5 group and the lipid retention in all additive-supplemented groups were significantly higher than those in the control group (P < 0.05). In serum, all additive-supplemented groups showed significantly higher glutathione peroxidase activity than the control group (P < 0.05). The activities of superoxide dismutase and catalase in the CA8, A3, C4A1.5, and C8A3 groups were significantly higher (P < 0.05), while the concentration of malondialdehyde was significantly lower than those in the control group (P < 0.05). Moreover, the total antioxidant capacity in the A3 and C4A1.5 groups, and lysozyme activity in the A3, C4A1.5, and C8A3 groups were significantly increased when compared to the control group (P < 0.05). In digestive enzyme, the protease activity in the A3, C4A1.5 groups, and amylase activity in the CA4, CA8, and C4A1.5 groups were significantly higher than those in the control group (P < 0.05). In intestinal microbiota, Firmicutes abundance was elevated in all additive groups, while the Fusobacteriota and Plesiomonas shigelloides abundance were decreased. In the intestinal histology, the CA8, A3, and C4A1.5 groups showed significantly higher villus height than the control group (P < 0.05). After the infection with Aeromonas hydrophila, the cumulative mortality of all additive-supplemented groups was significantly lower (P < 0.05), and the C4A1.5 group demonstrated the lowest mortality. In conclusion, the combined supplementation of 4 g/kg citric acid + 1.5 g/kg AZOMITE increased the growth, antioxidant, immune capacity, improved the intestinal morphology and microbial flora of juvenile largemouth bass, and promoted the resistance against Aeromonas hydrophila infection.

Effect of Echinacea purpurea (L.) Moench and its extracts on the immunization outcome of avian influenza vaccine in broilers

Ethnopharmacological relevanceEchinacea purpurea (L.) Moench (EP) is a perennial herbaceous flowering plant with immunomodulatory effects. However, the immunomodulatory effects of EP on broilers after vaccination are still unclear. Aim of the studyThe aim is to study the effect of EP and Echinacea purpurea (L.) Moench extracts(EE) on avian influenza virus (AIV) immunity, and further explore the potential mechanism of immune regulation. Materials and methodsBroilers were fed with feed additives containing 2% EP or 0.5% EE, and vaccinated against avian influenza. The samples were collected on the 7th, 21st, and 35th day after vaccination, and the feed conversion ratio (FCR) was calculated. Blood antibody titer, jejunal sIgA content, tight junction protein, gene and protein expression of TLR4-MAPK signaling pathway were also detected. ResultsThe results showed that vaccination could cause immune stress, weight loss, increase sIgA content, and up-regulate the expression of tight junction proteins, including zonula occludens-1 (ZO-1), Occludin, and Claudin-1, as well as the genes of Toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88), receptor-associated factor 6 (TRAF6), activator protein 1 (AP-1) protein gene expression on TLR4-mitogen-activated protein kinase (MAPK) signaling pathway, and the protein expression of MyD88, extracellular regulated protein kinases (ERK), and c-Jun N-terminal kinase (JNK). EP and EE could increase the body weight of broilers, further improve antibody titers, decrease FCR, increase sIgA levels, up-regulate the expression of tight junction proteins, including ZO-1, Occludin, and Claudin-1, as well as the genes of TLR4, MyD88, TRAF6, and AP-1 and the protein expression of MyD88, ERK, and JNK in the TLR4-MAPK signaling pathway. ConclusionIn conclusion, EP and EE can increase the broiler's production performance and improve vaccine immune effect through the TLR4-MAPK signaling pathway.

The impact of Bacillus subtilis DSM32315 and L-Threonine supplementation on the amino acid composition of eggs and early post-hatch performance of ducklings.

Poultry requires Threonine, an essential amino acid, and its metabolites for proper metabolic function. Threonine is crucial in the biosynthesis of mucin, which is essential for intestinal health and nutrient absorption. Bacillus subtilis (B. subtilis) is a potential substitute for antibiotic growth promoters in the poultry industry. The current study was designed to evaluate the simultaneous effect of L-Threonine (Thr) and B. subtilis DSM32315 supplementation on laying duck breeders in order to maximize performance. A total number of 648 female 23-week-old Longyan duck breeders were assigned to a 3 × 2 factorial design with six replicates of 18 birds per replicate. L-Thr was added to the control diet at concentrations of 0, 0.7, and 1.4 g/kg, equating to 3.9, 4.6, and 5.3 g Thr/kg, with or without B. subtilis strain DSM 32315 (0.0 and 0.5 g/kg). Increasing Thr concentrations improved egg production and ducklings' hatchling weight (p < 0.05). In addition, L-Thr supplementation resulted in a tendency for decreased feed conversion ratio without affecting egg quality. There was no significant effect (p > 0.05) of the dietary Thr levels on egg yolk and albumen amino acid concentrations. In contrast, the addition of B. subtilis decreased the concentrations of amino acids, excluding proline, in the egg white (albumen) and the egg yolk (p < 0.05). Furthermore, the supplementation of B. subtilis decreased (p < 0 0.001) the hatching weight of ducklings. The addition of B. subtilis without L-Thr decreased (p < 0.05) the hatchability of fertile eggs and the hatching weight of ducklings compared to those of ducks fed dietary L-Thr along with B. subtilis (p < 0.001). The combining L-Thr at 0.7 g/kg with B. subtilis DSM 32315 at 0.5 g/kg could increase eggshell quality, hatchability, and hatching weight. The current study revealed that the combination supplemented of L-Thr and B. subtilis DSM 32315 is recommended due to its positive effects on the eggshell percentage, hatchability and the body weights of newly hatched ducklings when dietary Thr was added at a rate of 0.7 g/kg and B. subtilis DSM 32315 at 0.5 g/kg. In addition, adding L-Thr separately at 0.7 g/kg could improve the egg production of duck breeders. Further studies are required to find the proper dosages of B. subtilis DSM 32315 with co-dietary inclusion of limiting amino acids in the diets of duck breeders. The findings of these trials will support feed additive interventions to transition into antibiotic-free diets.

Microalgae as a dietary additive for lambs: A meta-analysis on growth performance, meat quality, and meat fatty acid profile

This study aimed to evaluate the effects of dietary inclusion of microalgae (MIAs) on growth performance, meat quality, and fatty acid (FAs) profile of lamb meat, using a meta-analytic method. The data used were obtained from 18 peer-reviewed publications. The effect size was assessed using weighted mean differences (WMD) between experimental treatments (diets with MIAs) and control treatments (diets without MIAs). Dietary supplementation with MIAs increased (P < 0.05) dry matter intake and average daily gain and decreased feed conversion ratio (P = 0.005). In meat, MIAs supplementation decreased (P < 0.05) drip loss and Warner-Bratzler shear force and increased lightness (P < 0.001). The content of pentadecanoic, stearic, oleic, total ω-6 FAs, and the ω-6/ω-3 ratio of meat decreased in response to the dietary inclusion of MIAs (P < 0.05). In addition, MIA supplementation increased (P < 0.05) the content of linoleic, conjugated linoleic, eicosapentaenoic, docosahexaenoic, and total ω-3 FAs in meat. In conclusion, the dietary inclusion of microalgae can be used as a nutritional strategy to improve animal performance, meat quality, and fatty acid profile in lamb meat.

Increasing Phosphorus Digestibility in Common Carp (Cyprinus carpio L.) Farming Using Phytase and Citric Acid

The presence of antinutritional substances, such as phytate, in fish feed affects the digestibility and absorption of minerals and nutrients by fish, while reduced availability of phosphorus (P) in wheat-based feeds used in fish farming can increase pollution in the aquatic environment. Phosphorus digestibility can be effectively increased in aquaculture through the addition of both phytase and citric acid. The aim of our study was to investigate the effects of phytase enzyme and citric acid addition on P digestibility, production parameters and blood parameters in farmed common carp (Cyprinus carpio L.). Two trials were undertaken using the following experimental diets: control with no additives (C), low enzyme content (500 FTU/kg; L), high enzyme content (1,000 FTU/kg; H), low enzyme contents with 3% citric acid (LA), high enzyme contents with 3% citric acid (HA). Initial results showed that LA increased P digestibility by 27% and HA by 26%, with no increase detected using L and H. In the second trial, in which production and blood parameters were examined, use of LA and HA resulted in a 20% decreased feed conversion ratio and 11% higher specific growth rate. Furthermore, acidified diets resulted in an increased blood plasma calcium and inorganic P, without negative effects on any parameter. Addition of phytase and citric acid to C. carpio granulated feeds also has a positive influence on the environment by reducing excreted P.

Spineless cactus cladode is a viable replacement to barley and maize grains in the feed rations of dromedary camel calves.

No studies determined the use of spineless cactus cladodes in camel diets. The effect of replacing the main energy source in camel diets with fresh spineless cactus cladodes on growth performance was determined. Furthermore, the ability of morphology to predict cladodes yield was determined. A prediction model of spineless cactus cladode weight based on cladode volume was developed. Three cladodes per plants were randomly selected from 100 plants. Weight and volume were then recorded for each cladode. Sixteen male camel calves (196±18.2kg live weight and 430±5.55 days of age) were allotted to treatments, control (conventional camel fattening diet based on cotton seed hulls, cereal grains and agro-industrial by-products) or cactus (barley and maize grains in the control diet were replaced totally by fresh cactus cladode on dry matter basis). The study contained a 100-days growth trial and a 21-day digestibility trial (15 days of adaptation and 7 days of faeces collection). Blood samples were collected monthly from each animal. Cactus cladode volume predicted the dry weight with a high accuracy (prediction error=3.5%). Nutrient intake and nutrient digestibility did not significantly differ among the dietary treatments (p>0.05). The treatment significantly decreased feed conversion ratio by 1.52 points (p<0.05). All blood parameters were within the normal range of dromedary camels. Spineless cactus cladode is a potential replacement to the conventional energy sources in dromedary camel diets.

Dietary Olive Leaf Extract Differentially Modulates Antioxidant Defense of Normal and Aeromonas hydrophila-Infected Common Carp (Cyprinus carpio) via Keap1/Nrf2 Pathway Signaling: A Phytochemical and Biological Link.

Olive leaves are an immense source of antioxidant and antimicrobial bioactive constituents. This study investigated the effects of dietary incorporation of olive leaf extract (OLE) on the growth performance, hematobiochemical parameters, immune response, antioxidant defense, histopathological changes, and some growth- and immune-related genes in the common carp (Cyprinus carpio). A total of 180 fish were allocated into four groups with triplicate each. The control group received the basal diet without OLE, while the other three groups were fed a basal diet with the OLE at 0.1, 0.2, and 0.3%, respectively. The feeding study lasted for 8 weeks, then fish were challenged with Aeromonas hydrophila. The results revealed that the group supplied with the 0.1% OLE significantly exhibited a higher final body weight (FBW), weight gain (WG%), and specific growth rate (SGR) with a decreased feed conversion ratio (FCR) compared to the other groups (p < 0.05). An increase in immune response was also observed in the fish from this group, with higher lysosome activity, immunoglobulin (IgM), and respiratory burst than nonsupplemented fish, both before and after the A. hydrophila challenge (p < 0.05). Similarly, the supplementation of the 0.1% OLE also promoted the C. carpio's digestive capacity pre- and post-challenge, presenting the highest activity of protease and alkaline phosphatase (p < 0.05). In addition, this dose of the OLE enhanced fish antioxidant capacity through an increase in the activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx) and decreased hepatic lipid peroxidation end products (malondialdehyde-MDA), when compared to the control group, both pre- and post-infection (p < 0.05). Concomitantly with the superior immune response and antioxidant capacity, the fish fed the 0.1% OLE revealed the highest survival rate after the challenge with A. hydrophila (p < 0.05). A significant remarkable upregulation of the hepatic sod, nrf2, and protein kinase C transcription levels was detected as a vital approach for the prevention of both oxidative stress and inflammation compared to the infected unsupplied control group (p < 0.05). Interestingly, HPLC and UPLC-ESI-MS/MS analyses recognized that oleuropein is the main constituent (20.4%) with other 45 compounds in addition to tentative identification of two new compounds, namely oleuroside-10-carboxylic acid (I) and demethyl oleuroside-10-carboxylic acid (II). These constituents may be responsible for the OLE exerted potential effects. To conclude, the OLE at a dose range of 0.66-0.83 g/kg w/w can be included in the C. carpio diet to improve the growth, antioxidant capacity, and immune response under normal health conditions along with regulating the infection-associated pro-inflammatory gene expressions, thus enhancing resistance against A. hydrophila.

Effects of Cyperus alternifolius, Echinochloa pyramidalis, Typha angustifolia, and Imperata cylindrica on Growth Performance, Feed Digestibility, Gut Microbiota, Haemato-biochemical and Immunity Parameters in Broiler Chickens

The rhizomes of Cyperus (C.) alternifolius, Echinochloa (E.) pyramidalis, Typha (T.) angustifolia, and Imperata (I.) cylindrica are rich in secondary metabolites and have diverse pharmacological activities. The present study was designed to evaluate the effects of dietary C. alternifolius, E. pyramidalis, T. angustifolia, and I. cylindrical rhizomes on the performance of broiler chickens. A total of 384 day-old chicks were randomly assigned to six treatment groups (each treatment replicated four times). The first group received a basal diet (negative control), and the second group received a basal diet with 1 gr of antibiotic (Doxicycline, positive control). Other groups received a basal diet with 2 gr of each phyto-additives/kg feed. The results revealed that treatments had no significant effects on feed intake and carcass yield in chickens. The C. alternifolius and T. angustifolia significantly increased live weight and weight gain, and decreased feed conversion ratio, compared to negative control. The addition of C. alternifolius, T. angustifolia, and I. cylindrica to broilers’ diet significantly increased the apparent digestibility of dry matter and crude protein, compared to the negative control. Compared to the negative control, the lactic acid bacteria count significantly increased with the incorporation of T. angustifolia and I. cylindrica. The granulocytes count and globulins concentration were not affected by the different treatments. However, the lymphocyte count was significantly decreased with the diet containing E. pyramidalis compared to the negative and positive controls, and the diets containing C. alternifolius and T. angustifolia. The spleen and bursa weights and volumes significantly increased in all groups of chickens fed on phyto-additives, compared to the negative control. Except for haematocrit, which significantly increased with C. alternifolius and T. angustifolia in the treatments compared to the negative control, the feed additives did not significantly affect the hematological parameters. Compared to the negative control, T. angustifolia and I. cylindrica significantly increased HDL-cholesterol concentration in broiler chickens’ serum, while all treatment groups were comparable for all the other biochemical parameters. Incorporating 2 g of C. alternifolius and T. angustifolia in broiler chickens’ feed improves feed digestibility, enhances the population of lactic acid bacteria in the gut, and causes subsequent improvement in growth performance.

The digestive enzyme activity, intestinal microbiota and immune-related genes expression of snakehead fish (Channa argus) juveniles affected by dietary cricket (Gryllus testaceus) meal

This study aimed to investigate the potential of using cricket (Gryllus testaceus) meal as the main protein source in fish feed for snakehead fish (Channa argus) juveniles. A 10-week feeding trial was conducted to assess the effects of partial replacement of fishmeal (FM) with cricket meal (CM) on growth performance, digestive enzyme activity, intestinal microbial composition, liver antioxidant capacity, immune response and determine the appropriate replacement FM level with CM in juvenile Channa argus diet. Five isonitrogenous and iso-lipid experimental diets were formulated by replacing 0 %, 15 %, 30 %, 45 % and 60 % of FM with CM, respectively named T0 (control group), T15, T30, T45 and T60 groups. The results demonstrated T45 and T60 showed a significantly decreased feed conversion ratio (FCR) than T0 (P < 0.05). Crude lipid content was significantly higher in T45 and T60 than in T0 (P < 0.05). With increasing dietary CM content, the activities of amylase and lipase were significantly increased in T60 (P < 0.05). At the phylum level, 16S rDNA sequences revealed that Proteobacteria abundance was dominant in all treatments, while Ralstonia abundance had higher significance in T60 than others at the genus level (P < 0.05). The total antioxidant capacity (T-AOC) in liver in T30 and T45 were significantly higher than in T0 (P < 0.05). Glutathione peroxidase (GPx) activities had a significant increase in fish fed groups except T0 (P < 0.05), while malondialdehyde (MDA) content was significantly lower within T45 and T60 than T0 (P < 0.05). The up-regulated gene expression level (IL-1β, IL-10, and HSP70) and down-regulated expression level (IL-8) were showed in all treatments with CM replacement. HSP90 and Iκ-Bα expression levels were increased and peaked in T30 (P < 0.05). According to the results of the current study, in Channa argus diets, FM replacement with CM can be up to 30 % without compromising growth performance, enzyme activities, antioxidant capacity, intestinal microbiota, and immune response.

Dietary supplementation of multi-strain probiotic in male rainbow trout (Oncorhynchus mykiss) broodstock: Effects on feed efficiency, hemato-biochemical parameters, immune response, and semen quality

The present study aimed to determine the effects of dietary probiotic supplementation on feed efficiency, physiological parameters, and semen quality of male rainbow trout (Oncorhynchus mykiss) broodstock. For this purpose, a total of 48 breeders with an average initial weight of 1366.1 ± 33.8g were divided into 4 groups and 3 replicates. Fish were fed with diets containing 0 (control), 1 × 109 (P1), 2 × 109 (P2), and 4 × 109 (P3) CFU multi-strain probiotic kg-1 diet for 8weeks. According to the results, P2 treatment significantly enhanced body weight increase, specific growth rate, and protein efficiency ratio and decreased feed conversion ratio. Moreover, the highest values of red blood cells count, hemoglobin, and hematocrit values were observed in P2 treatment (P < 0.05). The lowest levels of glucose, cholesterol, and triglyceride were found in P1, P2, and P3 treatments, respectively. Also, the highest levels of total protein and albumin were obtained in P2 and P1 treatments (P < 0.05). Based on the results, plasma enzymes contents were significantly decreased in P2 and P3 treatments. In terms of immune parameters, the complement component 3, complement component 4, and immunoglobulin M levels were increased in all probiotic-fed treatments (P < 0.05). For spermatological features, the highest spermatocrit value, sperm concentration, and motility time were observed in the P2 treatment (P < 0.05). Consequently, we conclude that multi-strain probiotics can be used as functional feed additives in male rainbow trout broodstock to enhance semen quality, improve physiological responses, and better feed efficiency.