Dietary supplementation of Eucalyptus leaves enhances eggshell quality and immune response in two varieties of Japanese quails under tropical condition

Reduction of methane and nitrogen emission and improvement of feed efficiency, rumen fermentation, and milk production through strategic supplementation of eucalyptus (Eucalyptus citriodora) leaf meal in the diet of lactating buffalo (Bubalus bubalis)

Buffalo plays a compelling role in reducing malnutrition and ensuring food to the people of Asian countries by its major contribution to milk and meat pool of the livestock agriculture farming system in the region. As Asia is the home for more than 90% of world buffalo population, they are also one of the largest emitters of greenhouse gasses. Eucalyptus (Eucalyptus sp.) leaves are rich sources of naturally occurring essential oils and phenolic compounds, which could modulate rumen fermentation through mitigation of methanogenesis and nitrogen excretion along with stimulation of immune system and production performances of animals. Therefore, the present study investigated the impact of dietary inclusion of eucalyptus (Eucalyptus citriodora) leaf meal (ELM) on voluntary feed intake, rumen functions, methane emission, nutrient utilization, milk yield and fatty acids profile, and immune response in lactating buffalo (Bubalus bubalis). An in vitro experiment conducted with graded dose (10-40 g/kg) inclusion of ELM into the total mixed ration to select ideal level for feeding to lactating buffaloes, an improvement (P < 0.05) in feed degradability (IVDMD), microbial biomass and ruminal volatile fatty acids concentration with reduced (P < 0.05) methane and ammonia-N production were evidenced when ELM was added at 10-20 g/kg DM, beyond which negative effects on rumen fermentation were pronounced. An in vivo experimentation was conducted with sixteen Murrah (Bubalus bubalis) buffaloes of mean live weight, 544.23 ± 10.02 kg; parity, 2-4 at initial stage (~60 days) of lactation with average milk yield of 11.43 ± 1.32 kg and were divided into two groups (CON, ELM) of eight each in a completely randomized design. All the animals were kept individually on wheat straw-based diet with required quantity of concentrate mixture and green fodder. The control group buffaloes were fed a total mixed ration; however, the treatment group (ELM) was supplemented with 10 g/kg DM diet of dry grounded eucalyptus (Eucalyptus citriodora) leaves by mixing with the concentrate mixture. The feeding experiment was conducted for 120 days, including 15 days for adaptation to the experimental diets and 105 days for data recording. The nutrient digestibility (DM, OM, CP, and EE) was improved (P < 0.05) without affecting feed intake (P > 0.05) and fiber digestibility (NDF and ADF) in ELM supplemented buffaloes. Increased (P < 0.05) milk production and rumenic acid concentration (cis 9 trans 11 C18:2 CLA) were demonstrated with comparable (P > 0.05) milk composition and major fatty acids profile of milk in the supplemented buffaloes. Dietary inclusion of ELM reduced (P < 0.05) enteric methane production and fecal excretion of nitrogen. The health status of buffaloes fed ELM improved throughout the experimental period was improved by enhancing cell mediated (P = 0.09) and humoral (P < 0.01) immune responses without affecting (P > 0.05) major blood metabolites. The study described feeding ELM at 10 g/kg diet to lactating Murrah buffaloes as a natural source of phenols and essential oils to increase milk production and CLA content, reduce methane and nitrogen emissions, and improve health status. Thus, feeding of ELM could be beneficial for climate smart buffalo production system for enhancing milk production with lesser impact on environment.

The efficacy of polyphenols as an antioxidant agent: An updated review

Global production of the two major poultry products, meat and eggs, has increased quickly. This, in turn, indicates both the relatively low cost and the customers' desire for these secure and high-quality products. Natural feed additives have become increasingly popular to preserve and enhance the health and productivity of poultry and livestock. We consume a lot of polyphenols, which are a kind of micronutrient. These are phytochemicals with positive effects on cardiovascular, cognitive, anti-inflammatory, detoxifying, anti-tumor, anti-pathogen, a catalyst for growth, and immunomodulating functions, among extra health advantages. Furthermore, high quantities of polyphenols have unknown and occasionally unfavorable impacts on the digestive tract health, nutrient assimilation, the activity of digestive enzymes, vitamin and mineral assimilation, the performance of the laying hens, and the quality of the eggs. This review clarifies the numerous sources, categories, biological functions, potential limitations on usage, and effects of polyphenols on poultry performance, egg composition, exterior and interior quality traits.

Ameliorative impacts of sodium humate on heat-stressed laying Japanese quail (Coturnix coturnix Japonica)

A total of 300 laying Japanese quails (230.10 ± 20 g body weight) divided into four groups (15 birds in 5 replicates/group) were used to examine the impacts of dietary sodium humate (SH) supplementation at levels of 0% (control diet), 0.2%, 0.4% and 0.6% on egg variables and physiological merits of laying quails for 10 weeks under heat stress conditions (15 June and 23 August 2021). Results showed 0.4% SH increased (p < 0.05) weight (12.27 vs. 11.91 g), production (79.84% vs. 69.20%), mass (597.13 vs. 510.48 g) and brokenness (2.8% vs. 5.4%) of eggs as compared to control. Egg shape, shell thickness, shell strength and cholesterol content as well as feed conversion ratio were higher (80.2, 295.8 µm, 1.468 kg/cm,² 11.08 mg/g and 2.69, p < 0.05) in 0.4% SH than in control group (75.2, 279.0 µm, 1.304 kg/cm,²  14.94 mg/g and 2.76). Feed intake, percentages of eggs' shells, yolk, albumen and serum biochemistry (total protein, albumin, AST and HDL) were not altered with the dietary SH. Birds fed on SH diets showed higher levels of globulin, calcium and phosphorus, as well as lower contents of albumin/globulin ratio, triglycerides, cholesterol, corticosterone compared with the control. Regression analysis of antioxidants expected higher total antioxidant capacity (TAC), superoxide dismutase, glutathione peroxidase at 0.35%, and glutathione at 0.40% SH, while the lowest concentration of malondialdehyde was computed at 0.45%. Similarly, immunoglobulins (IgG and IgM) maximum values were determined at 0.35% and 0.40% levels. Moreover, the concentration of tumour necrosis factor-alpha increased (p < 0.05) in all SH levels as compared to the control group. It is conceivable to conclude that the dietary implementation of SH at a level of 0.4% improved egg variables and well-being aspects of laying quail exposed to heat stress conditions.

Impacts of polyphenols on laying hens' productivity and egg quality: A review

There has been a rapid increase in the world's output of main poultry products (meat and eggs). This reflects customer desire for these high-quality and safe products and the comparatively low price. Recently, natural feed additives, plants and products have been increasingly popular in the poultry and livestock industries to maintain and improve their health and production. Polyphenols are a type of micronutrient that is plentiful in our diet. They are phytochemicals that have health benefits, notably cardiovascular, cognitive function, antioxidant, anti-mutagenic, anti-inflammatory, antistress, anti-tumour, anti-pathogen, detoxification, growth-promoting and immunomodulating activities. On the other hand, excessive polyphenol levels have an unclear and sometimes negative impact on gastrointestinal tract health, nutrient digestion, digestive enzyme activity, vitamin, mineral absorption, laying hens performance and egg quality. As a result, this review illuminated polyphenols' various sources, classifications, biological activities, potential usage restrictions and effects on poultry, layer productivity and egg external and internal quality.

Phytogenic Feed Additives in Poultry: Achievements, Prospective and Challenges

Simple Summary

Plant secondary metabolites and essential oils also known as phytogenics are biologically active compounds that have recently attracted increased interest as feed additives in poultry production, due to their ability to promote feed efficiency by enhancing the production of digestive secretions and nutrient absorption, reduce pathogenic load in the gut, exert antioxidant properties and decrease the microbial burden on the animal’s immune status. However, the mechanisms are far from being fully elucidated. Better understanding the interaction of phytogenics with gastrointestinal function and health as well as other feed ingredients/additives is crucial to design potentially cost-effective blends.

Abstract

Phytogenic feed additives have been largely tested in poultry production with the aim to identify their effects on the gastrointestinal function and health, and their implications on the birds’ systemic health and welfare, the production efficiency of flocks, food safety, and environmental impact. These feed additives originating from plants, and consisting of herbs, spices, fruit, and other plant parts, include many different bioactive ingredients. Reviewing published documents about the supplementation of phytogenic feed additives reveals contradictory results regarding their effectiveness in poultry production. This indicates that more effort is still needed to determine the appropriate inclusion levels and fully elucidate their mode of actions. In this frame, this review aimed to sum up the current trends in the use of phytogenic feed additives in poultry with a special focus on their interaction with gut ecosystem, gut function, in vivo oxidative status and immune system as well as other feed additives, especially organic acids.

Influence of strain and flock age on geometrical and mechanical attributes of eggs produced from Japanese quail birds

We investigated how the geometrical and mechanical properties of eggshell of Japanese quail are affected by strain and flock age. Two strains of quail (white and gray) were used in the current experiment. The results showed that there was no significant difference for all geometric measurements due to strain effect. Eggs produced from the older birds showed significantly higher (P < 0.01) values compared with younger age for all studied traits. Eggs produced from quails at 22 weeks had a significantly (P < 0.01) darker yolk color than that of the younger age. Superiority in shell thickness, shell weight, and breaking force was detected in eggs of gray quails compared with white quails. On the other hand, the eggs from white quails had significantly higher values for static stiffness and Young's modulus as compared with those of gray counterparts. A significant decrease (P < 0.01) was found for fracture toughness and Young's modulus in eggs of aged birds. A significant negative relationship was found between the breaking force and both static stiffness and Young's modulus. A significant positive relationship was observed between breaking force and both shell thickness and shell percentage. The phenotypic correlation between eggshell breaking force and toughness was relatively high.

Proteome and Transcriptome Analysis of the Antioxidant Mechanism in Chicken Regulated by Eucalyptus Leaf Polyphenols Extract

Eucalyptus leaf polyphenols extract (EPE) has been proved to have various bioactivities, but few reports focus on its antioxidant mechanism in vivo. The purpose of this study was to elucidate the effect and mechanism of EPE dietary supplements on antioxidant capacity in chicken. A total of 216 chickens were randomly selected for a 40-day experiment. Four treatment groups received diets including the control diet only, the control diet + low EPE (0.6 g/kg), the control diet + moderate EPE (0.9 g/kg), and the control diet + high EPE (1.2 g/kg). Compared with control group, the glutathione peroxidase (GSH-Px) activity and glutathione (GSH) content in the breast muscle of the moderate EPE treatment group was significantly higher (p < 0.05), while the malonaldehyde (MDA) content in the moderate EPE group was reduced (p < 0.05). Moreover, proteomic and transcriptomic analyses of the breast muscle revealed that glutathione metabolism and the peroxisome were the two crucial metabolic pathways responsible for increased antioxidant capacity of the muscle. Accordingly, nine candidate genes and two candidate proteins were identified related to improved antioxidant status induced by EPE supplements. This research provides new insights into the molecular mechanism of antioxidant capacity in chickens treated with EPE dietary supplements.