Synthetic and phytogenic antioxidants improve productive performance, antioxidant activity, gene expression, and offspring quality in breeder hens subjected to heat stress.

This study aimed to investigate the efficacy of a synthetic source (a combination of vitamin E, vitamin C, selenium, and L-carnitine) and phytogenic sources (a combination of clove, green tea pomace, and Vietnamese coriander) in overcoming heat stress (HS) damage in female breeder hens on production, blood chemistry, sperm survival in the oviduct, antioxidant properties, gene expression, and quality of offspring. One hundred SUT female breeder hens were housed in individual cages and divided into 4 treatment groups: T1) basal diets in the thermoneutral (TN) zone; T2) basal diets under HS; 3) basal diets with synthetic antioxidants under HS; and T4) basal diets with phytochemical antioxidants under HS. The result revealed that HS condition had a negative effect on reducing final body weight, egg weight, and 1-day-old chick weight while increasing water intake and FCR and altered blood chemicals in breeder hens compared to TN breeder hens (P < 0.05). However, either synthetic or phytogenic antioxidants resulted in increased egg production and hatchability, while decreasing the number of late stages of embryo death during the incubation (P < 0.05). Furthermore, the synthetic antioxidants also improved the uniformity of chicks and reduced late-stage embryo death compared with phytogenic antioxidants (P < 0.05). HS breeder hens fed with either of the antioxidant sources exhibited higher antioxidant capacity in terms of DPPH and ABTS radical scavenging (in yolk, liver, and breast meat) and FRAP radical scavenging (in yolk and liver) and lower liver malondialdehyde than HS breeder hens fed with the control diet (P < 0.05). Additionally, the gene expression of antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase) in the liver was upregulated, whereas the expression of proinflammatory cytokines (nuclear factor-κB) and heat shock proteins (HSP70 and HSP90) was downregulated in breeder hens that received both antioxidant sources (P < 0.05). Future investigations should focus on the potential for combinations of synthetic and phytogenic antioxidants in diets for HS breeder hens.

Transcriptome analysis of the uterovaginal junction containing sperm storage tubules in heat-stressed breeder hens.

Sperm storage tubules (SSTs) in the uterovaginal junction (UVJ) of the oviduct are major sites of sperm storage after artificial insemination or mating. Female birds may regulate sperm motility in the UVJ. Heat stress can decrease the reproductive ability of broiler breeder hens. However, its effects on UVJ remain unclear. Changes in gene expression aid in understanding heat stress-affected molecular mechanisms. Herein, we wanted to conduct a comparative transcriptomic analysis to identify the differentially expressed genes (DEGs) in the UVJ of breeder hens under thermoneutral (23°C) and heat stress (36°C for 6 h) conditions. The results indicated that cloacal temperatures and respiratory rates were significantly increased in heat-stressed breeder hens (P < 0.05). Total RNA was extracted from the hen UVJ tissues containing SSTs after heat exposure. Transcriptome analysis identified 561 DEGs, including 181 upregulated DEGs containing heat shock protein (HSP) transcripts and 380 downregulated DEGs containing immune-related genes, such as interleukin 4-induced 1, radical S-adenosyl methionine domain containing 2, and 2'-5'-oligoadenylate synthetase like, in heat-stressed hens. Gene Ontology analysis revealed the significantly enriched terms involving HSPs. Kyoto Encyclopedia of Genes and Genomes analysis identified 9 significant pathways, including the protein processing in endoplasmic reticulum (11 genes including HSPs), neuroactive ligand-receptor interaction (13 genes including luteinizing hormone/choriogonadotropin receptor), biosynthesis of amino acids (4 genes including tyrosine aminotransferase), ferroptosis (3 genes including heme oxygenase 1), and nitrogen metabolism (carbonic anhydrase [CA]-12 and CA6) pathways. Protein-protein interaction network analysis of DEGs revealed 2 large networks, one containing upregulated HSPs and the other containing downregulated interferon-stimulating genes. Overall, heat stress inhibits innate immunity in the UVJ tissues of broiler chickens, and heat-stressed chickens protect their cells by increasing the expression levels of HSPs. The identified genes are potential candidates for further exploration of the UVJ in heat-stressed hens. The identified molecular pathways and networks increase our understanding of the sperm storage reservoirs (UVJ containing SSTs) within the reproductive tract and may be used to prevent heat stress-induced fertility loss in breeder hens.

Assessment of lactic acid bacteria isolated from the chicken digestive tract for potential use as poultry probiotics.

OBJECTIVE: The use of probiotics as an alternative to antibiotics in animal feed has received considerable attention in recent decades. Lactic acid bacteria (LAB) have remarkable functional properties promoting host health and are major microorganisms for probiotic purposes. The aim of this study was to characterize LAB strains of the chicken digestive tract and to determine their functional properties for further use as potential probiotics in poultry. METHODS: A total of 2,000 colonies were isolated from the ileum and cecal contents of the chickens based on their phenotypic profiles and followed by a preliminary detection for acid and bile tolerance. The selected 200 LAB isolates with exhibited well-tolerance in acid and bile conditions were then identified by sequencing the 16S rDNA gene, followed by acid and bile tolerance, antimicrobial activity, adhesion to epithelial cells and additional characteristics on the removal of cholesterol. Then, the two probiotic strains (L. ingluviei and L. salivarious) which showed the greatest advantage in vitro testing were selected to assess their efficacy in broiler chickens. RESULTS: It was found that 200 LAB isolates that complied with all measurement criteria belonged to five strains, including L. acidophilus (63 colonies), L. ingluviei (2 colonies), L. reuteri (58 colonies), L. salivarius (72 colonies), and L. saerimneri (5 colonies). We found that the L. ingluviei and L. salivarius can increase the population of LAB and Bifidobacterium spp. while reducing Enterobacteria spp. and Escherichia coli in the cecal content of chickens. Additionally, increased concentrations of valeric acid and short chain fatty acids were also observed. CONCLUSION: This study indicates that all five Lactobacillus strains isolated from gut contents of chickens are safe and possess probiotic properties, especially L. ingluviei and L. salivarius. Future studies should evaluate the potential for growth improvement in broilers.

Antioxidant properties and cytotoxic effects of selected edible plants in Southeast Asia for further use as phytogenic antioxidant additives.

Excessive free radicals in human and animal bodies can cause oxidative stress (OS) which damages cells and tissues. Plant materials with high antioxidant potential would resolve the OS problem. Thus, this study proposed to investigate the total phenolic (TPC) and flavonoid contents (TFC), antioxidant capacities and cytotoxicity in 17 edible plant materials from herbs, fruits, vegetables and plant by-products available in Southeast Asia for future use in the food or feed industry. Among 17 plant materials, Syzygium aromaticum (clove), Camellia sinensi (green tea pomace) from the beverage industry and Persicaria odorata (Vietnamese coriander) showed a prominent amount of TPC and TFC. These three plants and their combination (1:1:1 ratio, v:v:v) also possessed a remarkable antioxidant function in terms of DPPH, ABTS and FRAP, as well as showing a strong ROS inhibition through HepG2 cells. The cytotoxicity test of the crude extract of clove, green tea pomace and Vietnamese coriander, or their combination can be used between 0.032 and 0.255, 0.011 to 0.088, 0.022 to 0.178 and 0.021 to 0.346 mg/mL, respectively, without impeding cell viability. A combined mixture of clove, green tea pomace and Vietnamese coriander revealed the synergistic properties of antioxidants and cell safety. This indicates that there is a potential use of various antioxidant bioactive compounds in plant materials tested for use as phytogenic antioxidant additives.

Extraction of dietary fibers from cassava pulp and cassava distiller's dried grains and assessment of their components using Fourier transform infrared spectroscopy to determine their further use as a functional feed in animal diets.

OBJECTIVE: The present study was to investigate the extraction conditions of dietary fiber from dried cassava pulp (DCP) and cassava distiller's dried grains (CDG) under different NaOH concentrations, and the Fourier transform infrared (FTIR) was used to determine the dietary fiber components. METHODS: The dried samples (DCP and CDG) were treated with various concentrations of NaOH at levels of 2%, 4%, 6%, and 8% using a completely randomized design with 4 replications of each. After extraction, the residual DCP and CDG dietary fiber were dried in a hot air oven at 55°C to 60°C. Finally, the oven dried extracted dietary fiber was powdered to a particle size of 1 mm. Both extracted dietary fibers were analyzed for their chemical composition and determined by FTIR. RESULTS: The DCP and CDG treated with NaOH linearly or quadratically or cubically (p< 0.05) increased the total dietary fiber (TDF) and insoluble fiber (IDF). The optimal conditions for extracting dietary fiber from DCP and CDG were under treatment with 6% and 4% NaOH, respectively, as these conditions yielded the highest TDF and IDF contents. These results were associated with the FTIR spectra integration for a semi-quantitative analysis, which obtained the highest cellulose content in dietary fiber extracted from DCP and CDG with 6% and 4% NaOH solution, respectively. The principal component analysis illustrated clear separation of spectral distribution in cassava pulp extracted dietary fiber (DFCP) and cassava distiller's dried grains extracted dietary fiber (DFCDG) when treated with 6% and 4% NaOH, respectively. CONCLUSION: The optimal conditions for the extraction of dietary fiber from DCP and CDG were treatment with 6% and 4% NaOH solution, respectively. In addition, FTIR spectroscopy proved itself to be a powerful tool for fiber identification.

Mix of cassava pulp, napier grass, and enzymes can be used as low cost alternative feed ingredient for laying hens.

Two experiments were carried out to evaluate the effect of mixed cassava pulp and napier grass (MCN) supplemented with multi-component enzymes on the hen performance and egg quality as well as nutrient digestibility. In experiment 1, forty laying hens (Isa Brown) of 34 weeks in age were randomly allotted to 5 groups: control and 5, 10, 15, and 20% MCN for 10 days (one bird per cage, eight cage replicates). The results indicated that dry matter, and organic matter digestibilities, or nitrogen retention (P > 0.05) showed no significant alteration when used MCN up to 20%. In experiment 2, one hundred and eighty Isa Brown laying hens of 67 weeks in age were randomly assigned to 5 groups (control and 4 MCN: 5, 10, 15, and 20%) and raised for 8 weeks. It revealed that the inclusion rate of MCN up to 20% did not affect the productive performance, plasma cholesterol concentration, cecal microbial populations, or ammonia production (P > 0.05). In addition, egg yolk cholesterol was found to be lower in laying hens fed 20% MCN compared to 5% MCN (P < 0.05), but no significant differences compared to the control. In conclusion, it is indicated that MCN can be used as a partial part of an energy source in laying hen diets with no adverse effects on productive performance, nutrient digestibility or egg quality.

Lactobacillus ingluviei C37 from chicken inhibits inflammation in LPS-stimulated mouse macrophages.

Probiotics are growing alternatives to antibiotics, and can contribute to the prevention and treatment of diseases and enhance livestock production. Lactobacillus (L.) ingluviei is a novel probiotic species with growth-enhancement effects; however, this species remains poorly understood, and there have been (to our knowledge) no studies focusing on its immunological effects. Here, we isolated L. ingluviei C37 (LIC37) from chicken and evaluated the bacterium's immunomodulatory properties to explore its probiotic potential. Real-time quantitative PCR and ELISA showed that in vitro exposure of inflammation-stimulated mouse peritoneal macrophages to heat-killed LIC37 led to decreases in tumor necrosis factor-α and interleukin (IL)-6 levels and an increase in IL-10. These findings suggested that LIC37 exerts anti-inflammatory effects by modulating cytokine profiles. This species may be an attractive probiotic bacterial strain for use in animal production.

Response of Thai indigenous crossbred chickens to various dietary protein levels at different ages.

The objective of this study was to evaluate the protein requirement of Korat chicken (KRC), a slow-growing cross strain between the Thai indigenous fighting cock (Leung Hang Khoa) and the modern genotype females. Four periods were considered: from hatch to 21 days (phase 1), 22 to 42 days (phase 2), 43 to 63 days (phase 3), and 64 to 84 days of age (phase 4). A total of 3120 mixed-sex KRC were randomly allocated to 5 dietary protein levels containing 19, 20, 21, 22, and 23% with 2978 kcal of ME/kg (900 birds in phase 1); 18, 19, 20, 21, and 22% with 3151 kcal of ME/kg (780 birds in phase 2); 16, 17, 18, 19, and 20% with 3200 kcal of ME/kg (720 birds in phase 3); and 15, 16, 17, 18, and 19% with 3200 kcal of ME/kg (720 birds in phase 4) with 6 replicates in a completely randomized design. The results showed that BW, BW gain, average daily gain (ADG), and protein intake (P < 0.05) were increased with increasing dietary protein (P < 0.05) in all phases. However, FI, feed cost per kg of BW gain, energy intake, and blood urea nitrogen of chickens were not found to be significantly different among treatments. On the other hand, increasing dietary protein levels depressed the protein efficiency ratio of chickens from hatch to 21 and from 64 to 84 days of age (P < 0.05), and tended to decrease it from 22 to 42 (P = 0.08) and from 43 to 63 (P = 0.07) days of age as well. According to a broken-line regression analysis, the protein requirements of chickens from hatch to 21 and from 22 to 42 days of age for maximum BW gain were 21.26 and 20.45%, respectively. While the requirements of maximum responses for BW gain and FCR in the period of 43 to 63 days of age were 18.00 and 18.04%, respectively, and in the period of 64 to 84 weeks of age were 17.94 and 18.03%, respectively.

Effect of energy density of diet on growth performance of Thai indigenous (50% crossbred) Korat chickens from hatch to 42 days of age.

The aim of the current study was to investigate the effect of the energy density of diet on the growth performance of Thai indigenous crossbred (50%) chickens known as Korat chicken (KRC). A total of 1440 mixed-sex KRC (720 birds in each phase) were randomly allocated to 4 dietary treatments containing 2750, 2900, 3050, or 3200 kcal ME/kg diet with 6 replicates of each treatment in a completely randomized design. The experimental diets were tested from hatch to 21 days and from 22 to 42 days of age. In both age groups, body weight gain was not affected (P > 0.05) by the ME density of the diets. Feed intake however decreased with increasing (metabolizable energy) ME (P < 0.05), thereby significantly improving the feed conversion ratio (FCR). Broken-line analysis was performed to estimate the ME content of feed to obtain minimum FCR and maximum protein efficiency ratio (PER) values. Minimum FCR and maximum PER values were found when the diet contained 3000 kcal ME/kg from hatch to 21 days of age and 3175 kcal ME/kg from 22 to 42 days of age, respectively, using diets containing 7.5 and 6.6 g of protein/100 kcal ME, respectively. In conclusion, we established that the ME requirements of KRC from hatch to 21 days and 22 to 42 days of age were 3000 and 3175 kcal/kg, respectively.

Digestibility, productive performance, and egg quality of laying hens as affected by dried cassava pulp replacement with corn and enzyme supplementation.

Two experiments were conducted to investigate the potential use of dried cassava pulp (DCP) supplemented with enzymes as an alternative feed ingredient in laying hen diets. In experiment 1, 45 laying hens (Isa Brown) aged 45 weeks were placed in individual cages to measure nutrient digestibility for 10 days. Nine dietary treatments were control and DCP as a replacement for corn at 20, 25, 30, and 35% supplemented with mixed enzymes (cellulase, glucanase, and xylanase) at 0.10 and 0.15%. Results showed that the use of DCP at 20-35% added with mixed enzymes had no negative effects on dry matter digestibility, while organic matter digestibility and nitrogen retention decreased with increased DCP up to 30-35% in diets. Both enzyme levels (0.10 and 0.15%) showed similar results on nutrient digestibility and retention. In experiment 2, a total of 336 laying hens aged 32 weeks were randomly allocated to seven dietary treatments (control and DCP-substituted diets at 20, 25, and 30%) supplemented with mixed enzymes (0.10 and 0.15%). Diets incorporated with 20-30% of DCP and supplemented with mixed enzymes at both levels had no significant effects on egg production, egg weight, feed intake, egg mass, feed conversion ratio, protein efficiency ratio, or egg quality, except for egg yolk color being decreased with an increase of DCP in diets (P < 0.05). In conclusion, it is suggested that DCP supplemented with enzymes can be used as an energy source in laying hen diets up to 30% without showing negative effects on nutrient digestibility, productive performance, or egg quality.