Day Of Hatch Research Articles

The Expression of Proteases and the Oligopeptide Transporter PepT1 in the Yolk Sac Membrane, Proventriculus, and Small Intestine During the Development of Anas platyrhynchos domestica Embryo

The role of the yolk sac membrane (YSM) and digestive tract in the processing of egg yolk proteins during embryogenesis is unexplored in the duck Anas platyrhynchos domestica. Here, we investigated in the duck embryo the function of the YSM, proventriculus, and small intestine in protein digestion and uptake. We tested the expression of aminopeptidase N (APN) and the oligopeptide transporter PepT1 as well as the expression of cathepsin B (CTSB) and cathepsin D (CTSD) lysosomal genes in the YSM during incubation days 12, 14, 16–18, 20, 22, 24, 26, and 28 (the day of hatch). Also, we examined embryonic duck pepsinogen (EDPg) expression in the proventriculus and APN and PepT1 expression in the small intestine. In the YSM, CTSD expression was weak compared to that of CTSB, and the expression of CTSB, APN, and PepT1 reached its maximum on day 24 and decreased afterwards. In the proventriculus, EDPg expression peaked on days 17 to 20 and decreased thereafter. The APN and PepT1 expression levels were highest in the jejunum and ileum and reached their maximum on day 28. Our results suggest that the YSM plays a role in the degradation and uptake of the peptides that are digested by the activated yolk proteases, and it also functions in the lysosomal digestion of yolk lipoproteins. Furthermore, the proventriculus is possibly involved in the digestion of yolk proteins. Finally, the jejunum and ileum appear to be the primary sites for peptide digestion and absorption at the end of the incubation.

Selenium nanoparticles affect chicken offspring's intestinal health better than other selenium sources

This study aimed to assess the effects of maternal diets containing various selenium (Se) sources on the intestinal mucosal function in the jejunum of chicken offspring. A total of 630, 18-wk-old Hy-Line Grey hens and 70 18-wk-old Hy-Line Grey breeders were randomly allocated into 7 groups, with 5 replicates in each group (18 hens and tow roosters). After 4 wk of Se depletion, the birds were fed either a nonsupplemented basal diet (control) or the same basal diet supplemented with 0.15 mg/kg selenium nanoparticles (Nano-Se), 0.30 mg/kg Nano-Se, 0.30 mg/kg selenocysteine (Sec), 0.30 mg/kg sodium selenite (SS), 0.30 mg/kg selenomethionine (SeMet), or 0.15 mg/kg Nano-Se + 0.15 mg/kg Sec, for 8 wk. Frtilized eggs were collected and incubated during the final week of the experiment. Jejunal tissues from embryonic d 18 and the hatch day were collected for analysis, and the 7-d survival rate of the offspring was recorded. Compared to the control, the maternal diet of 0.30 mg/kg Nano-Se, 0.30 mg/kg Sec, and 0.30 mg/kg SeMet significantly increased the survival of 7-day-old offspring (P < 0.05). The maternal diet supplemented with 0.30 mg/kg Nano-Se significantly increased intestinal villus height and the villus height/crypt depth ratio in chicks at embryonic d 18 and in 1-day-old (P < 0.05). The maternal diet containing 0.30 mg/kg Nano-Se and Sec increased the mRNA expression levels of tight junction proteins in 1-day-old offspring (P < 0.05). Supplemental 0.30 mg/kg Nano-Se significantly increased the mRNA expression levels of marker genes in intestinal enteroendocrine, stem, and Paneth cells (P < 0.05). In 1-day-old chicks, the number of intestinal goblet cells, as well as the mRNA expression levels of intestinal mucin2 (Muc2) and goblet cell differentiation factors (Spdef and C-myc), were the highest in diets supplemented with 0.30 mg/kg Nano-Se. Moreover, the expression levels of intestinal Muc2 and Spdef in chicks at embryonic d 18 was the highest with 0.30 mg/kg Nano-Se supplementation (P < 0.05). Supplementing with 0.30 mg/kg Nano-Se significantly reduced reactive oxygen species levels and decreased the mRNA expression levels of apoptosis-related genes in 1-day-old chicks (P < 0.05). Additionally, 0.30 mg/kg Nano-Se supplementation significantly down-regulated NLRP3 pathway gene expression in 1-day-old chicks (P < 0.05). In conclusion, maternal dietary supplementation with Nano-Se improved jejunal microarchitecture, antioxidant levels, and the expression of tight-junction protein in chicken offspring along with supporting goblet cell development by inhibiting the NLRP3 signaling pathway.

Effect of in ovo feeding with a multi-strain probiotic containing effective microorganisms and Zn-Gly chelate on the fatty acid profile, lipid profile, and malondialdehyde level in the serum and tissues of newly-hatched chickens

Modern poultry production strives to ensure the safety of food products by constantly improving the health parameters of birds. Multi-strain probiotics containing effective microorganisms and microelements, especially zinc in chelated form, currently play an important role in poultry feeding. We hypothesized that supplementation of chicken embryos with a multi-strain probiotic and glycine-zinc chelate may influence lipid metabolism in the serum and tissues of newly hatched chicks, leading to an increase in the body's antioxidant capacity. Therefore, the aim of the study was to assess the lipid profile, fatty acid profile and malondialdehyde (MDA) concentration in the serum and tissues of newly hatched chickens supplemented in ovo with a multi-strain probiotic and zinc glycine chelate. The experiment was conducted on 1,500 fertilized hatching eggs obtained from 36-week-old commercial broilers (Ross x Ross 308). A multi-strain probiotic and zinc glycine chelate (Zn-Gly) were administered on the 17th day of incubation. Samples of peripheral blood and tissues of the liver, small intestine (ileum), pectoral muscle, thigh muscle and yolk sac, collected on the day of hatch and at 7 days post-hatch, were used to analyse biochemical parameters and determine the malondialdehyde level and fatty acid profile. The results indicate that in ovo supplementation with a multi-strain probiotic and Zn-Gly chelate on the 17th day of incubation affects fat metabolism. Simultaneous administration of a multi-strain probiotic and Zn-Gly chelate did not increase the concentration of polyunsaturated fatty acids (PUFAs) in the muscles. In birds treated with Zn-Gly chelate, the PUFA concentration was increased in the muscle tissue in the period up to 7 days post-hatch, i.e. during the development of the chicks. Moreover, the analysis of the results confirmed that in ovo supplementation with a multi-strain probiotic and Zn-Gly chelate stimulates the synthesis of saturated fatty acids (SFAs), mainly stearic, palmitic and myristic acids, and improves the ratio of PUFAs to SFAs. The multi-strain probiotic and Zn-Gly chelate administered in ovo did not cause excessive MDA synthesis in the tissues, suggesting that these preparations reduce oxidative stress in the developing embryo and newly hatched chick.

Evaluating performance, intestinal lesions, and immunity related genes in heritage and modern broiler breeds during a necrotic enteritis challenge

In this comparative study, the differential responses of heritage (ACRB; Athens Canadian Random Bred) and modern (Cobb) broilers to a necrotic enteritis (NE) challenge were evaluated. The design was a 2×2 factorial with breed (ACRB and Cobb) and challenge (non-challenged and NE-challenged) as main factors. On day (d) of hatch, 96 male chicks (48 ACRB and 48 Cobb) were allocated to 4 experimental groups with 8 replicate cages and 3 birds/cage. On d 14, birds in the NE-challenged groups were orally gavaged with 3,000 Eimeria maxima sporulated oocysts followed by 2 doses of ∼1×108 CFU of Clostridium perfringens on d 19 and 20. On d 21, 2 birds/cage were necropsied to score NE lesions, and spleen and cecal tonsils (CT) samples were collected from 1 bird/cage for assessing mRNA abundance. Challenged ACRB birds exhibited reduced growth performance and relative growth performance compared to challenged Cobb birds. There was no significant interaction between breed and challenge during the challenge period (d 14-21) for mortality. However, there was a challenge main effect (P ≤ 0.05) on mortality as manifested by greater NE-associated mortality compared to non-challenged birds. No significant breed × challenge interaction or breed main effect on lesion scores were observed in the duodenum, jejunum, and ileum. NE-challenged Cobb birds exhibited greater mRNA abundance of IL-18, TNFα, TLR1.2, TLR2.1, CCR5, CCR6, CCL20, and AvBD1 in CT compared to NE challenged ACRB birds. There was a significant breed × challenge interaction effect on mRNA abundance of IL-10, AvBD13, NK-Lysin, and LEAP2 in the spleen. Moreover, a main effect of breed was observed in IL-1β, IL-18, TNFα, TLR2.1, CCR5, CCL20, and NK-Lysin where ACRB birds had higher mRNA abundance than Cobb birds (P ≤ 0.05). The observed differences in performance, pathology, and mRNA abundance between ACRB and Cobb broilers during the NE challenge highlight the distinct immune response profiles of heritage and modern breeds, emphasizing the need for breed-specific nutritional, managerial, and genetic selection programs for modulating immune responses during enteric disease challenges.

Research Note: Effects of on-farm and hatchery hatching on broiler performance, intestinal lesions, and immune response during a subclinical necrotic enteritis challenge

The effects of traditional and on-farm hatching systems on broiler performance and health under a subclinical necrotic enteritis (NE) challenge were evaluated in this study. A 2×2 factorial study explored the effects of place of hatch (on-farm hatched [OFH] vs. hatchery hatched [HH]) and NE challenge (nonchallenged vs. challenged) on broilers. Cobb 500 eggs (∼E19) were acquired from a commercial hatchery; 840 eggs were placed in pens on clean shavings in prewarmed floor pens and allowed to hatch out, while 927 eggs were placed in a hatcher set under standard practices. On day (d) of hatch, all chicks were weighed and randomly distributed to 4 treatments (8 replicate pens each and 30 birds/pen). The OFH birds were placed immediately after sorting while HH birds were placed back in the hatcher overnight to simulate commercial hatchery procedures. After placing HH birds, feed and litter in the challenge group pens were sprayed with a live oocyst coccidia vaccine as a predisposing factor to NE. The small intestines of 3 male chicks per pen were scored for NE lesions (n = 24) on d 8 (peak NE challenge) and jejunal samples were collected from 1 bird per pen for RNA extraction and qPCR on d 8 and d 14. Data were analyzed using JMP Pro17 and significance between treatments was identified by LSD (P ≤ 0.05). Regardless of the hatching system, the subclinical NE challenge caused a significant reduction in average daily gain (ADG) and average daily feed intake (ADFI), and increased feed conversion ratio (FCR) until d 28 (P ≤ 0.05). Moreover, OFH birds exhibited significantly better growth (P ≤ 0.05) through d 28 but had similar performance to HH birds by d 42. There were no significant differences in NE lesion scores between HH and OFH groups. In conclusion, OFH system resulted in better broiler performance compared to HH system under both no-challenge and challenge conditions during the starter and grower periods. This practice may hold potential for further exploration by the industry as an alternative to traditional hatching, aiming to improve the welfare and productivity of broilers.

Sex Identification of Black Swan (Cygnus atratus): Possible at the First Day of Hatching

Sex Identification of Black Swan (Cygnus atratus): Possible at the First Day of Hatching

Highly virulent avian brood-parasitic species show elevated embryonic metabolic rates at specific incubation stages compared to less virulent and non-parasitic species.

As the avian embryo grows and develops within the egg, its metabolic rate gradually increases. Obligate avian brood-parasitic birds lay their eggs in the nests of other species to avoid the costs of parental care, and all but one of these brood-parasitic species are altricial at hatching. Yet the chicks of some altricial brood-parasitic species perform the physically demanding task of evicting, stabbing or otherwise killing host progeny within days of hatching. This implies a need for high metabolic rates in the embryo, just as precocial species require. Using flow-through respirometry in situ, we investigated embryonic metabolic rates in diverse avian brood parasite lineages which either kill host offspring (high virulence) or share the nest with host young (low virulence). High-virulence brood parasite embryos exhibited higher overall metabolic rates than both non-parasitic (parental) species and low-virulence parasites. This was driven by significantly elevated metabolic rates around the halfway point of incubation. Additionally, a fine-scale analysis of the embryos of a host-parasitic pair showed faster increases in metabolic rates in the parasite. Together these results suggest that the metabolic patterns of the embryos of high-virulence parasites facilitate their early-life demands.

Temperature manipulation during incubation: effect on embryo development and incidence of white striping and expression of related genes in broiler chickens from two commercial breeds

ABSTRACT 1. This study evaluated the effects of cyclic eggshell temperature between 10 and 14 d of embryogenesis on traits viz. the expression of MYOZ2, PPARγ and GPx7 in breast muscle, meat quality and incidence of white striping at slaughter age. 2. Eggs were obtained from Cobb and Ross broiler breeders to investigate the response of breeds to eggshell temperature, which regulated air temperature. A total of 784 eggs were incubated at either the control eggshell temperature (37.8°C) from 0 to 18 d or exposed to cyclic high eggshell temperature (CHT) at 38.8°C for 6 h/d between 10 and 14 d of incubation. The temperature was 36.8°C between 18 and 21 d. Hatched chicks were reared under optimum rearing conditions. The birds were sampled at 19 d of incubation, at hatch and at 42 d post-hatch. 3. There was no effect of eggshell temperature on yolk-free body weight and residual yolk sac weight. The CHT chicks had wider breasts on the day of hatching. 4. At hatch and 42d post-hatch, PPARγ expression in Cobb-CHT was upregulated 4.78-fold and downregulated 3.28-fold, respectively, compared to the Cobb-control. At slaughter age, chickens from Ross-CHT had 1.98- and 2.33-fold upregulated PPARγ and GPX7 expressions, respectively, compared to Ross-control. The CHT increased GPx7 expression in the Cobb-CHT day-old chicks compared to the Cobb-control. On ED19, MYOZ2 expression was upregulated in Cobb and downregulated in Ross by CHT. 5. The effects of breed and eggshell temperature on pH15, L*, a*, expressible juice and cooking loss were not significant. The CHT increased the incidence of severe white striping lesions in Ross chickens. 6. It was concluded eggshell temperature modulated embryo development, incidence of white striping and expression of related genes differently in the two commercial breeds.

Neonatal α-Ketoglutaric Acid Gavage May Potentially Alleviate Acute Heat Stress by Modulating Hepatic Heat Shock Protein 90 and Improving Blood Antioxidant Status of Broilers.

This study investigated the effect of neonatal α-ketoglutaric acid (AKG) gavage feeding on broilers. The first experiment was conducted to determine the effect of AKG on day-old broilers. A total of seventy-two-day-old Ross 308 broiler chicks were divided into four treatment groups: (i) Two groups of chicks with gavage feeding of 0.6 mL of distilled water (DDW) for four consecutive days (CON); (ii) chicks fed with 0.6 mL of 0.1% AKG dissolved in DDW on the day of hatch (AL) followed by 0.2%, 0.3%, and 0.4% for three consecutive days; and (iii) chicks fed with 0.6 mL of 0.2% AKG dissolved in DDW on the day of hatch (AH) followed by 0.4%, 0.6%, and 0.8% for three consecutive days. Twenty-four hours after the first gavage feeding, six birds per treatment were slaughtered to study the organ development. Chicks fed with AKG showed higher absolute (p = 0.015) and relative (p = 0.037) weights of the gizzard. The AH group had higher absolute (p = 0.012) and relative (p = 0.035) heart weights. The second experiment was carried out to determine the effect of AKG on 15-day-old broilers under acute heat stress (AHS) for 3.5 h at 33 ± 1 °C. Forty-eight birds (12 per treatment) were raised until 15 days of age, divided into four treatments with equal numbers (n = 12), and given one of the following four treatments: (i) CON group reared at standard temperature (25 ± 1 °C) (CON-NT); (ii) CON group subjected to AHS (33 ± 1 °C) for 3.5 h (CON-HT); (iii) AL group subjected to AHS (33 ± 1 °C) for 3.5 h (AL-HT); and (iv) AH group subjected to AHS (33 ± 1 °C) for 3.5 h (AH-HT). There was a significant reduction in the change in BW (ΔBW, p = 0.005), an increase in the final rectal temperature (RTf) (p = 0.001), and a decreased final body weight (BWf) for all the treatments under AHS. Further, AHS led to an increased expression of hepatic heat shock protein (HSP)70 (p = 0.009), nicotinamide adenine dinucleotide phosphate hydrogen oxidase (NOX)1 (p = 0.006), and NOX4 (p = 0.001), while nuclear factor erythroid 2-related factor (NRF2), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase 1 (GPX1) remained significantly unaffected. Hepatic expression of HSP90 decreased in the AL-HT treatment as compared to CON-HT (p = 0.008). Plasma antioxidant status measured by malondialdehyde (MDA) concentration and antioxidant balance (AB) improved linearly (p = 0.001) as the concentration of AKG increased. Neonatal gavage feeding of AKG could potentially alleviate heat stress in broilers by enhancing plasma antioxidant levels and modulating HSP90 expression in the liver.

Variations in vertical distribution of developing snow crab Chionoecetes opilio and red snow crab Chionoecetes japonicus (Crustacea, Decapoda, Majoidea) larvae in experimental temperature gradients

ABSTRACT In the Sea of Japan, field studies have found snow crab and red snow crab larvae occur between the surface and depths of up to 550 m and 1100 m, respectively. In this region, snow crab larvae hatch at depths of 240–260 m and red snow crab larvae hatch at 1000–1500 m. To understand their vertical distribution during the larval period, we investigated the upward swimming speed of newly hatched larvae (first-stage zoea) and the behaviour of all larval stages (first and second zoeal and megalopal stages) in a temperature gradient under laboratory conditions. Our results showed that the larvae have the potential to reach the surface within a few days of hatching. As the larvae developed, they preferred greater depth and lower temperatures; although they temporarily rose to higher levels immediately after each moult. The zoeae and megalopae of both species did not occur beyond the 16 and 6°C temperature layers, respectively. The preferred position of the larvae in the gradient temperature did not differ between the two species. The present study suggests that Chionoecetes larvae transported to unsuitable temperatures may not die, but could escape from low temperatures by upward swimming and from high temperatures by sinking.

P-193 Does the day of laser-assisted hatching affects the clinical outcomes of single vitrified blastocyst transfer cycles? A propensity score–matched study

Abstract Study question What is the impact of different days of laser-assisted hatching on the clinical outcomes of single vitrified blastocyst transfer cycles? Summary answer Clinical pregnancy of single vitrified blastocyst were similar, irrespective of day of laser-assisted hatching. What is known already Assisted hatching aims to create a weakness in the ZP to aid embryo hatching and implantation. Day 5 assisted hatching is typically performed shortly before the embryo transfer while day 3 assisted hatching is performed before blastocyst culture expansion and vitrification. Despite over 25 years of use, there is still no standardized protocol for AH, and published data on its efficacy are controversial and inconclusive. While efforts have been made to study the link between AH techniques and pregnancy outcomes, there is limited consensus for optimizing AH protocols like the day of performance. Study design, size, duration This was a retrospective study based on data collected between January 2022 and October 2023. Propensity score matching (PSM) was performed in a 1:1 matching ratio. 123 patients of day 3 laser assisted hatching group (D3 LAH group) were successfully matched to 123 cycles of day 5 laser assisted hatching group (D5 LAH group). The D5 LAH group was from March 2023 to October 2023, and the D3 LAH from January 2022 to February 2023. Participants/materials, setting, methods Single vitrified day 5 embryo transfer, embryos survived after warming, and patient agreed to receive LAH were include in this study. We excluded donation cycles, missing data, severe female factors. Primary outcome is clinical pregnancy. Comparisons between groups were performed with chi-square test, Fisher’s exact test, Mann–Whitney U test, and Student’s t-test where appropriate, with a P value &amp;lt;0.05 considered statistically significant. A multivariable analysis in the GEE model was adjusted for the confounding factors. Main results and the role of chance After propensity score matching, there was no significant difference in patient characteristics between the groups, creating similar cohorts. For example, the frequency of primary infertility was significantly different between groups initially (61% vs 46.7% in D5 LAH vs D3 LAH respectively, P = 0.004). Following propensity score matching the rate of primary infertility was similar in both groups (with SMD=0.08). Standardized mean difference (SMD) &amp;lt; 0.1 suggests adequate variable balance after propensity matching. Clinical pregnancy rate were similar between two groups: 66/123 (53.7%) D3 LAH cycles and 75/123 (61%) D5 LAH cycles. When generalized estimating equation were performed: only TE grade, but not the day of laser assisted hatching, was noted to be an independent predictor of clinical pregnancy (OR = 0.068; 95% CI: 0.005-0.977; p = 0.048). Poor TE grade had a weak negative relationship with clinical pregnancy of single blastocyst cycles. Limitations, reasons for caution The main limitation of the study is its retrospective design and small sample size. Wider implications of the findings Clinical outcomes are comparable between day 3 laser assisted hatching and day 5 laser assisted hatching, although clinical pregnancy can be slightly improved with higher TE grade. Trial registration number not applicable

In-ovo injection of Bacillus subtilis, raffinose, and their combinations enhances hatchability, gut health, nutrient transport- and intestinal function-related genes, and early development of broiler chicks

An experiment was conducted to assess the response of chicks to in-ovo injection of Bacillus subtilis (probiotic), raffinose (prebiotic), and their combinations. The study used 1,500 embryonated eggs allotted to 10 groups/ 6 replicates (150 eggs/group). The experimental treatments were: 1) un-injected control (NC); 2) sham (sterile distilled water) (PC); 3) probiotic 4 × 105CFU/egg (LBS); 4) probiotic 4 × 106CFU/egg (HBS); 5) prebiotic 2 mg/egg (LR); (6 prebiotic 3 mg/egg (HR); 7) probiotic 4 × 105CFU + prebiotic 2 mg/egg (LBS+LR); 8) probiotic 4 × 105CFU + prebiotic 3 mg/egg (LBS+HR); 9) probiotic 4 × 106CFU + prebiotic 2 mg/egg (HBS+LR); and 10) probiotic 4 × 106CFU + prebiotic 3 mg/egg (HBS+HR). Results showed that in-ovo inclusion of Bacillus subtilis, prebiotic, and their combinations improved hatchability, yolk-free chick weight, and chick weight compared to the control group. Moreover, the in-ovo treatment reduced residual yolk weight on the day of hatch compared to the control group. Different levels of in-ovo B. subtilis alone or combined with raffinose significantly (P ≤ 0.001) reduced total bacterial count and total yeast and mold count compared to the negative control group. Total coliform and E. coli decreased significantly (P ≤ 0.001) in groups treated with probiotics, prebiotics, and synbiotics with different doses during incubation compared to those in the control. Clostridium spp. was not detected in the groups injected with B. subtilis alone or combined with raffinose. In-ovo probiotics and synbiotics (LBS+LR & LBS+HR) significantly (P ≤ 0.001) increased ileal villus length compared to other groups. In-ovo treatment increased mRNA expression of JAM-2 compared to the control group. The fold change significantly increased in group LBS+HR for genes MUC-2, OCLN, VEGF, SGLT-1, and EAAT-3 compared to the negative control. In conclusion, in-ovo injection of a low dose of B. subtilis plus a high or low dose of raffinose can positively affect hatching traits, cecal microbial populations, intestinal histomorphometry, nutrient transport- and intestinal function-related genes, and chick quality of newly hatched broiler chicks.

Developmental morpho-analysis of the caecum in Japanese quail embryos (Coturnix coturnix japonica).

In the current study, we are focusing on the microanatomical structure of quail caecum during the prehatching time to try to understand the function and the role of each cell-built quail caecum reaching how caecum plays an essential role in immunity and absorption. The morpho-developmental features of the quail caecum were described in detail daily from the third incubation day (ID) till hatching time, investigating the gross morphology, microscopic, and ultrastructure using light and scanning electron microscope. The embryonic caecum appeared grossly as two lateral outpocketings with blinded ends, emerging laterally at the junction between the small and large intestine (the ileocaecal junction). The primordia of two caeca, represented by two lateral swellings from the hindgut on the fourth ID, continued growing till the day of hatching, where the caecal wall consisted of three apparent layers: mucosa, musculosa, and serosa. At the time of hatching, the quail caecum was still not fully mature and will continue growing posthatching. The findings in this study can be applied in further studies intended to understand the physiological mechanisms of the caecum during prehatching and posthatching periods. RESEARCH HIGHLIGHTS: Caecum is one of the hindgut derivatives that started as two lateral swellings. The caecal wall consisted of three layers; mucosa, musculosa, and serosa. The caecum plays an essential role in immunity maintenance. Caecum continues to grow posthatching as it is not fully mature at hatching time.

The developmental pattern related to fatty acid uptake and oxidation in the yolk sac membrane and jejunum during embryogenesis in Muscovy duck

This study aimed to investigate the developmental change of body growth and gene expression related to fatty acid uptake and oxidation in the yolk sac membrane (YSM) and jejunum during embryogenesis in Muscovy ducks. The weights of embryos and yolk sac (YS) (5 embryos per replicate, n = 6) were recorded on embryonic days (E)16, E19, E22, E25, E28, E31, and the day of hatch (DOH). The fat and fatty acid contents in YSM, jejunal histology, and gene expression related to fatty acid metabolism in YSM and jejunum were determined in each sampling time. Among the nonlinear models, the maximum growth is estimated at 2.83 (E22.5), 2.67 (E22.1), and 2.60 (E21.3) g/d using logistic, Gompertz, and Von Bertalanffy models, respectively. The weight of YS, and ether extract-free YS as well as the amounts of fat and fatty acids in YS decreased (P < 0.05) linearly, whereas the villus height, crypt depth, villus height/crypt depth, and musculature thickness in jejunum increased (P < 0.05) linearly during embryogenesis. The mRNA expression of CD36, SLC27A4, and FABP1 related to fatty acid uptake as well as the mRNA and protein expressions of PPARα and CPT1 related to fatty acid oxidation increased in a quadratic manner (P < 0.05) in both YS and jejunum, and the maximum values were achieved during E25 to E28. In conclusion, the maximum growth rate of Muscovy duck embryos was estimated at 2.60 to 2.83 g/d on E21.3 to E23.5, while the accumulations of lipid and fatty acid in YS were decreased in association with the increased absorptive area of morphological structures in jejunum. The gene and protein expression involved in fatty acid metabolism displayed a similar enhancement pattern between YSM and jejunum during E25 to E28, suggesting that fatty acid utilization could be strengthened to meet the energy demand for embryonic development.

Effect of different synbiotic administration methods on growth, carcass characteristics, ileum histomorphometry, and blood biochemistry of Cobb-500 broilers.

To combat enteric infections and antibiotic resistance in the poultry industry, researchers seek alternatives such as probiotics, prebiotics, and synbiotics as growth promoters. Synbiotics support probiotic growth through the supply of essential nutrients. The study's objectives were to assess the most effective delivery methods for synbiotics and evaluate their growth, histomorphometric, and hematological impacts on Cobb-500 broilers. Two studies, independently conducted, employed a completely randomized design. One hundred and eighty viable eggs in the first trial were assigned to three groups: Control (T1), sterile water (T2), and synbiotic in sterile water (T3). On the 21st day of hatching, hatchability, day-old body weights, and ileum samples for histomorphometric analysis were recorded. In the second trial, out of 500 viable eggs, 200 eggs were fed in ovo with synbiotics (PoultryStar® sol, Biomin Singapore Pte Ltd, Singapore) on 17.5 days and 300 were set aside without in ovo injection. The treatments were control (T1), in water synbiotic (T2), in ovo synbiotic (T3), combination of in ovo synbiotic and synbiotic in feed (T4), and synbiotic in feed only (T5). On 21 and 42 days, blood, ileum, and visceral organ samples were collected for laboratory analysis. Data on weight gain, daily feed intake, and water consumption were recorded for 42 days. The initial experiment's results revealed a decrease in hatchability, slight weight increase, and significant intestinal morphological changes with the use of an in ovo synbiotic. Applying synbiotic through various methods in the second trial yielded better growth results, lower blood cholesterol, and significantly longer (p < 0.05) villi on 21 days. Using the in ovo method to administer synbiotics lowered hatchability. Use of synbiotics with any method or in combination enhances growth, ileum structure, dressing yield, feed efficiency, and cholesterol levels in blood. Synbiotics enhance gut health and overall performance in broilers when used through diverse approaches.

Effects of Hatching Eggs Storage at Room Temperature on Hatching Performance and Day Old Chick Quality of Arab Chickens

This study evaluated the effect of hatching egg storage at room temperature on hatching performance and day old chick quality of Arab chickens. Two hundreds hatching eggs were obtained at the same day from 55-weeks-old Arab chicken flocks. Hatching eggs were then randomly distributed into four treatments, including 1 day storage (1DS), 4 days storage (4DS), 7 days storage (7DS), and 10 days storage (10DS). Each of those treatment using five replicates and each of replicate consisted of 10 hatching eggs. Temperature and relative humidity in the storage room were 27.9 ± 0.55 °C and 55.4 ± 4.84%, respectively. At the end of each storage duration, hatching eggs were incubated at temperature and relative humidity of 37.8 ± 0.08 °C and 58.94 ± 5.66%, respectively, for 516 hours. Result showed that egg storage duration for up to 10 days did not affect (P &gt; 0.05) fertility. However, 4DS treatment had a higher (P &lt; 0.05) hatchability of set eggs and hatchability of fertile eggs. Embryonic mortality was also lower (P &lt; 0.05) in 4DS than the other treatments. Egg storage duration had no effect (P &gt; 0.05) on chick length, hatch yield, and Pasgar score. Whereas, chick weight in 1DS and D4S was higher (P &lt; 0.05) than 7DS and 10DS. Furthermore, saleable chicks in 4DS also higher (P &lt; 0.05) than the other treatments. It could be concluded that hatching egg storage at room temperature for 4 days provides optimum hatching performance and day old chick quality of Arab chickens.

Comparison effects of Natural and Artificial lighting on selected blood physiological variables of broilers grown to 56 days of age

Light is one of the major enviro-climatic factors in poultry houses that influences physiology and metabolic processes and impact poultry welfare, health, production and behaviors. This study compared the effects of natural and artificial lighting on selected blood physiological variables of broilers grown to 56 days of age. In each of the two trials, a total of 704 (352 males/352 females) 1-d- old Ross x Ross 708 chicks were obtained from a commercial hatchery on day of hatch. The design structure was a randomized complete block design with two treatments and eight replications per trial. Birds were equally and randomly distributed into 16 environmentally controlled rooms in groups of 44 (22 males/22 females) per room. Thus, each of the two treatments were represented by eight rooms with total of sixteen replicates. Temperature and RH on d 1 were maintained at 90 ± 2.1°F and 50 ± 5%, respectively across all treatments rooms. Temperature was decreased by 4 °F per week until it reached 66 °F at 56 d of age. Feed and water were provided ad libitum. Birds were provided a four phase-feeding program (Starter: 0-14 d, Grower: 15-28 d, Finisher: 29-42 d, and Withdrawal: 43-56 d). Blood samples (3 ml) were collected from the brachial wing vein of 3 males and 3 females birds per room on d 28, 42, and 56 which were then analyzed immediately for whole blood physiological variables. Blood plasma samples were analyzed for T3, T4, and corticosterone concentrations. Results showed that artificial light significantly increased sO2 (P &lt; 0.049), SaO2 (P &lt; 0.031), and decreased RHb (P &lt; 0.044) which may be due to slight difference in body weights, but the changes were all within physiological ranges for this species. In addition, blood glucose and plasma corticosterone concentrations were not affected by treatments, signify a similar level of physiological stress between the two light types. In conclusion, physiological variables examined in this study were unaffected by both natural and artificial lighting. However, birds exposed to artificial lighting had slightly increased body weight in comparison with birds reared under natural lighting, which may have a significant impact in commercial poultry production. USDA Agricultural Research Service. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Comparative analysis of reproductive tract microbiomes in modern and slower-growing broiler breeder lines.

The reproductive tract microbiome in hens is of interest because bacteria in the reproductive tract could potentially affect fertilization and egg production, as well as integrate into the forming egg and vertically transmit to progeny. The reproductive tract microbiome of 37-week-old modern commercial Cobb breeding dams was compared with that of dams from a broiler Legacy line which has not undergone selection since 1986. All animals were kept together under the same management protocol from day of hatch to avoid confounders. In regards to reproductive abilities, Cobb dams' eggs weighed more and the magnum section of their reproductive tract was longer. In regards to microbiome composition, it was found that the reproductive tract microbiomes of the two lines had a lot in common but also that the two breeds have unique reproductive tract microbiomes. Specifically, the order Pseudomonadales was higher in the magnum of Legacy dams, while Verrucomicrobiales was lower. In the infundibulum, Lactobacillales were higher in the Legacy dams while Verrucomicrobiales, Bacteroidales, RF32 and YS2 were lower. our results show that breeding programs have modified not only the physiology of the reproductive tract but also the reproductive tract microbiome. Additional research is required to understand the implications of these changes in the reproductive tract microbiome on the chicken host.

Histomorphometrical and histochemical study of small intestine development in local chicken (Gallus gallus domesticus) and duck (Anas platyrhynchos domesticus) embryos

This study demonstrated for the first time the histomorphometry of the small intestine (SI) and distribution of goblet and Paneth cells, collagen, and smooth muscle fibers in (SI) of the local chicken and duck during embryological development using the combined PAS and Alcian blue (pH2.5), Geimsa, and Masson's trichrome stains. One hundred and four fertilized chicken eggs and one hundred and forty fertilized duck eggs were collected from Mosul city. The sample placed in an incubator with automatic movement, ventilation, and humidity was (60%) and the temperature was (37.7 °C) for chicken and (37.5 °C) for duck. The histomorphometry showed significant differences between chicken and duck embryos at the 19th and 21st days of incubation of the villi's length, width, and apparent surface area. As for the epithelium height and the intestinal crypts, there were significant differences between chicken and duck embryos at the 18th and 20th days of incubation in the ileum and jejunum. Furthermore, the mucosa was thicker in chicken embryos in the day of hatching, the submucosa was thicker in ducks during the 18th day of the incubation in the duodenum. During day 15 of the incubation in chicken embryos in the jejunum and ileum, the muscularis layer was thicker in the duodenum and jejunum and less thick in the ileum, and the collagen fibers were less too in the duck embryos at hatching d. The serosa was thicker in the duck embryos. The percentage of the goblet cells was higher with a larger density in duck embryos than chicken at hatching day. Paneth cells were characterized by acidic granular cytoplasm. The achieved outcomes of histomorphometry and the density variances of the glycoprotein secretion are probably linked with numerous definite roles of (SI) parts in the progressions of nutrient absorption.

The developmental architecture of the crop of quail embryos (Coturnix coturnix): Morphometric, light and scanning electron microscopy.

The present study focused on the histogenesis of the crop in quail embryos. The developmental sequence was recorded from day 10 of incubation to the hatching day (17th day) by gross anatomy, morphometric analysis and by using light and scanning electron microscope (SEM). Grossly, the crop was distinguished as an enlarged pouch of the cervical oesophagus on the 12th day of incubation. Histologically, the development of the crop began on the 10th day of incubation. The muscularis mucosae was observed as a small, thin layer of myoblast cells on the 10th day, then it appeared as longitudinally arranged smooth muscle fibres with progression of the developmental age till hatching day. The submucosal layer was also observed on the 10th day, while the lamina propria, muscular layer (inner circular and outer longitudinal layers of smooth muscle fibre) and glandular primordia were detected on the 12th day. The epithelial cells of crop revealed affinity for PAS stain and AB-PAS on the 10th day of incubation till the 17th day, while the affinity for AB stain appeared on the 14th day of incubation. Additionally, the glandular cells showed the positive for AB, PAS and AB-PAS on the 12th day of incubation. SEM sections showed variable sizes of the openings of the oesophageal glands. In conclusion, the present study provided a detailed overview of the histogenesis of the crop in quail embryos.