Yolk Sac Weight Research Articles

Interactions between broiler parent stock age and egg pre-incubation duration: effects on embryo development, hatchability, day-old chick weight, and yolk sac weight

Egg storage is a common practice in commercial hatcheries, but prolonged storage can negatively impact hatchability, causing a significant problem for the poultry industry. Repeated pre-incubation could mitigate the decline depending on the age of the parent stock. The study investigated the interactions between parent stock age (30, 45, and 58 weeks) and repeated pre-incubation on the hatchability and embryo development of 15-day stored eggs from Ross 308 parent stock. Three different pre-incubation durations were employed during storage: no pre-incubation and twice at the 5th and 10th days of egg storage for either 4 or 8 h. For each parent stock age, 3 600 eggs collected on the same day from the same parent stock were used for hatchability assessment. The duration of pre-incubation was determined as the eggshell temperature increased from 28 °C to a maximum of 35 °C and then cooled to 28 °C; the persistency at 35 °C was either 1 or 4 h for the total pre-incubation period. The hatchability of both set and fertile eggs and early, middle, and late embryonic mortality depended on the parent stock’s age (P < 0.001). Pre-incubation alone did not have any impact on hatchability. Conversely, a significant interaction was observed between parent stock age and pre-incubation duration on the hatchability of fertile eggs (P = 0.001). At 30 weeks of parent stock age, both durations of pre-incubation positively influenced the hatchability. At 45 weeks of parent stock age, pre-incubation length had no effect on hatchability. At 58 weeks of parent stock age, a longer pre-incubation period, 2 × 8 h, was associated with decreased hatchability. Early embryonic mortality was not influenced by pre-incubation. However, a significant interaction was observed (P = 0.003). At 30 weeks of parent stock age, both short and long lengths of pre-incubation were associated with a decrease in early embryonic mortality. However, at 45 and 58 weeks, pre-incubation did not significantly affect early embryonic mortality. Additionally, longer pre-incubation periods significantly increased middle mortality compared to untreated eggs (P = 0.035). The median of embryo development for untreated eggs was the same across all ages (stage 10). In the older parent stock (45 and 58 weeks), repeated pre-incubation increased variability in embryo development, while in the younger parent stock, repeated pre-incubation decreased variability in embryo development. In conclusion, the duration and the frequency of pre-incubation should be specified based on the age of the parent stock.

Early-life immunomodulation by carvacrol delivered in ovo in broiler chickens

In the first 2 wk after hatching, broiler chickens are vulnerable to enteric pathogens due to underdeveloped gastrointestinal and immune systems. Carvacrol has been reported to improve digestive and immune functions. This study aimed to optimize immune development of broiler chickens by delivering carvacrol in ovo. Effects of 2 in ovo treatments delivered at embryonic day (E)17.5 (saline or carvacrol) were evaluated at 3 stages (E19.5, hatch, and d 14 posthatch). Hatchability, performance parameters, lymphoid organ and yolk sac weights were determined. Histomorphology assessment was performed for jejunal samples at hatch and bursa of Fabricius samples at hatch and d 14. Gene expression of immune-relevant genes was determined for jejunal, bursal, and yolk sac samples over time. At hatch, BW was 0.85% lower (P = 0.02) after in ovo carvacrol delivery compared to the controls. Interactions between in ovo treatment and age were found for gene expression. At hatch, carvacrol treatment resulted in lower expression of proinflammatory cytokines IL-8 and IFN-γ in the yolk sac compared to the controls (P = 0.05 and < .001, respectively) suggesting a potential role for carvacrol-mediated immune modulation. At d 14, carvacrol treatment led to lower expression of proinflammatory cytokine IL-6 in the bursa compared to the controls (P = 0.002). In ovo carvacrol delivery led to bursal histomorphometric changes, including a larger cortex in the bursal follicles (P = 0.03), and a higher cortex/medulla ratio (P = 0.04) compared to the controls, indicating increased B-cell stimulation and maturation. Main effects were found for carvacrol treatment in the jejunum, with overall higher expression of proinflammatory mediators IL-1β and NF-κB, and anti-inflammatory IL-10 compared to the controls (P = 0.04, 0.02, and 0.02 respectively) from E19.5 to d 14. Age-related main effects showed various alterations in expression dynamics of immune-related genes across all tissues over time. Our findings suggest changes in immune parameters occur as the chicken develops, but these mostly do not interact with in ovo carvacrol treatment. In ovo carvacrol treatment alters immune activity of broiler chickens independent of age.

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.

Effect of Genotype and Holding Duration on Some Post-Hatch Traits of Day-Old Broiler Pure Line Chicks

In this study, it was aimed to investigate the effects of varying holding durations on some post-hatching characteristics of broiler pure line chicks with different selection backgrounds. Fifty d-old chicks from each of 3 dam (A1, A2, A3) and 1 sire (B1) ANADOLU-T broiler pure lines were used. Ten chicks of each genotype were treated with holding durations of 0, 12, 24, 36 and 48-h after hatching. At the end of each holding duration, individual chick weight (g), weight loss (g, %), chick length (mm), wing feather length (mm), rectal temperature (°C), yolk sac weight and percentage (g, %) and yolk-free body mass (g) were determined. Hatching egg weights were similar in A1 (60.9 g), A2 (60.9 g) and B1 (61.1 g) lines, but higher than A3 (59.2 g) (P

Effects and Interactions of Incubation Time and Preplacement Holding Time on Mortality at Placement, Yolk Sac Utilization, Early Feeding Behavior and Broiler Live Performance.

The effects and interactions of incubation time and chick preplacement holding time on mortality at placement, utilization of yolk sac, crop filling rate, early feeding-drinking behavior, and broiler live performance were investigated. Ross 308 broiler hatching eggs from a 39-week-old flock were set in two identical setters in a commercial hatchery, with the setting time 12 h earlier in one machine. At the end of incubation, chicks were removed from the hatchers at the same time. Thus, the incubation times were either 504 h (normal incubation time (NIT) treatment) or 516 h (longer incubation time (LIT) treatment). After the pull time, chicks from each incubation time group were subjected to either 6, 24, 48, 60, or 72 h preplacement holding times. At placement, chicks were given access to feed and water. In total, 19,200 chicks were randomly assigned to a total of 10 subtreatment groups (2 incubation times × 5 preplacement holding times). Therefore, a total of 1920 chicks were used in each subtreatment group for the grow-out period in a commercial broiler house. For the first week of the experiment, 160 randomly selected as-hatched (not sexed) chicks were placed in 12 replicate floor pens (120 total pens). From the second week of age onward, chicks from two pens were combined into six replicate pens, with 320 chicks per replicate (60 total pens). An interaction was found between incubation time and preplacement holding time for residual yolk sac (RYS) weight (g, %) (p < 0.001). RYS weight was greater at pull time and at 6 and 24 h of preplacement holding in the NIT treatment compared to the LIT treatment, while differences were no longer evident at 48-72 h. The lowest percentage of chicks with full crops and eating activity was observed in the shortest preplacement holding time (6 h) group at 3 h after placement. As expected, the initial BW at placement clearly decreased with increasing duration after the pull time (p < 0.05), with the highest and lowest weights found in the 6 and 72 h holding time treatments, respectively. This BW difference was still evident at 35 d after placement and chicks held for the longest period after the pull time (72 h) showed the lowest BW (p < 0.001). However, there was no significant difference between the 6 and 60 h preplacement holding times. Mortality during the first 7 d after placement increased only when the preplacement holding time was extended to 72 h (p = 0.031). Similarly to the 7 d results, chicks held for 72 h exhibited higher 0-35 day mortality compared to those held for 6 or 24 h (p = 0.028). Neither BW nor mortality was affected by incubation time treatment at 35 d after placement (p > 0.05). It can be concluded that there were no significant differences in average BW and mortality, up to and including a 60 h holding time under thermal comfort conditions, but a 72 h preplacement holding time resulted in final BW and mortality being negatively affected. In addition, LIT tended to have a beneficial effect on BW and mortality compared to NIT when the preplacement holding time was shorter (6-24 h) but had a negative effect for extended holding times (48-72 h).

Effects of the in ovo injection of an Escherichia coli vaccine on the hatchability and quality characteristics of commercial layer hatchlings

In the commercial egg industry, avian pathogenic Escherichia coli (APEC) can lead to significant economic loss. The Poulvac E. coli vaccine (PECV) is a commercially available attenuated live vaccine commonly applied via spray or drinking water to protect against losses associated with colibacillosis. The PECV has not been tested in layer hatching eggs using in ovo injection. Therefore, the purpose of this experiment was to determine the effects of injecting 50 μL of different doses of the PECV into Hy-Line W-36-layer hatching eggs on the hatchability and quality characteristics of hatchlings. At 18 d of incubation (DOI), treatments included 1 noninjected and 1 diluent-injected control. Furthermore, PECV treatments included a full dose (4.4×108E. coli CFU) or serial dilutions of the full dose to produce 4.4×106, 4.4×104, or 4.4×102 CFU doses of E. coli. In ovo injections targeted the amnion. Percent hatchability of live embryonated eggs (HI), percent residue eggs, hatchling mortality, and female chick whole and yolk-free BW, relative yolk sac weight, and body length were among the variables examined. Treatment significantly (P < 0.0001) affected HI, with HI being highest in the control groups (97.3% in the noninjected and 94.2% in the diluent-injected), and with HI values being 89.0, 88.9, 84.4, and 71.2% in the 4.4×102, 4.4×104, 4.4×106, and 4.4×108 CFU E. coli dose treatments, respectively. The percentage of live embryos that did not complete hatch but that pipped internally (P=0.024) or externally (P < 0.0001) were significantly affected by treatment, with percentages being highest in the 4.4×108 CFU treatment. Female chick body length was significantly (P < 0.0001) affected by treatment and was longer in both control groups and in the 1×102 CFU E. coli treatment in comparison to all other treatments. Yolk-free female chick BW was significantly (P=0.034) affected by treatment and was lower in the 4.4×106 CFU and 4.4×108 CFU treatments when compared to the diluent-injected control group. An increase in the E. coli concentration administered in the amnion of embryonated layer hatching eggs at 18 DOI decreased hatch success and female chick yolk-free BW and body length.

Embryonic injection of Lactobacillus plantarum PA01 alters the microbial diversity in the gastrointestinal tract of the broilers before and after hatching

The total number of intestinal microbiotas is low, and the intestinal tract develops rapidly and imperfectly at the embryonic stage. Embryonic period as a particular physiological stage is an important time window to explore how to regulate organismal health by probiotics. Therefore, this experiment was conducted to investigate the effect of embryonic injection of Lactobacillus plantarum PA01 at embryonic d 14 (E14) on the microbiome of the contents of the gizzard, cecum at embryonic d 20 (E20) and cecum at d 1 posthatch (D1) by 16S rRNA sequencing. Results showed that PA01 had no significant effect on broiler body weight and yolk sac weight at E20 and D1 (P > 0.05). PA-01 altered the Shannon index and β diversity of the gizzard at E20 (P < 0.05), increased the abundance of Firmicutes (P < 0.05), and decreased the relative abundance of Proteobacteria, Bacteroidota, and Actinobacteriota (P < 0.05). At the genus level of the microbiota, PA01 significantly increased the relative abundance of Lactiplantibacillus (P < 0.05). At 20 embryos, PA01 altered the α and β diversity indices (P < 0.05) and decreased the relative abundance of Salmonella (P < 0.05) of the cecal microbiota. The biomarkers of PA01 group were Lactobacillales, Blautia, Lachnospiraceae, and Asinibacterium. Embryonic injection of PA01 altered the E20 intestinal microbes. PA01 altered the β-diversity index of the 1-day-old cecum (P < 0.05), and there was no significant effect on microbial composition at the phylum and genus level (P > 0.05). LefSe analysis revealed that the biomarkers of the PA01 group were Lactobacillaceae, Lactiplantibacillus, Moraxellaceae, and Acinetobacter. Biomarkers in the Con group were Devosia, Bacillus, Nordella, Mesorhizobium, and Pseudolabrys. PA01 increased acetic acid in the gastrointestinal tract at E20 along with acetic and butyric acid in cecum of 1-day-old. In conclusion, embryo-injected L. plantarum PA01 altered the structure and metabolites of the microbial flora before and after hatching, in particular promoting the colonization of Lactobacillus.

Determination of Hatching Performance, Yolk-Sac Absorption, and Larval Growth Rates in Abant Trout (Salmo trutta abanticus), Brook Trout (Salvelinus fontinalis), and their Hybrids

In this study, hatching performance, yolk-sac absorption, and growth rates of Abant trout (Salmo trutta abanticus), brook trout (Salvelinus fontinalis), and their hybrids were investigated. In this contex, relationships between duration (days) and total larvae length, total larvae wet weight, dry larvae body weight and yolk-sac weights, and larval growth were determined. At the end of the study, eye pigmentation, hatching, and larval survival rates were defined as 99.50%, 97.68%, 98.97% for Abant trout, 87.35%, 68.97%, 71.54% for brook trout, 96.12%, 64.18%, 56.82% for S.t.a. ♀ x S.f. ♂ hybrid and for S.f. ♀ x S.t.a. ♂ hybrid 14.98%, 0.45%, respectively. The results indicated there were significant linear relationships between degree-day and length, total wet weight, dry body weight, and dry yolk-sac weight in Abant trout, brook trout, and their hybrids. This relationship has been demonstrated as decreasing in the yolk-sac and as increasing in others. As a result of crossing, it was observed that the hatching efficiency of hybrid (S.t.a.♀ x S.f.♂) was similar to brook trout, and growth performance was similar to Abant trout. The results will help further studies and will contribute to the management practices of the stocks of Abant trout, brook trout, and their hybrids.

The effect of storage periods and SPIDES on embryonic mortality, hatching characteristics, and quality of newly hatched chicks in broiler eggs

sEgg storage duration can affect embryo mortality, hatching characteristics, hatching time, and post-hatch chick quality. In order to assess these effects, the impact of storage duration (5 days, 10 days, 15 days) and short incubation period during egg storage (SPIDES) investigated further 18, 900 eggs of broiler breeder (ROSS 308) in 3 × 2 factorial arrangement design. In the SPIDES treatment, the egg shell temperature was raised from its storage temperature (18 °C) and held at 100 °F for 3.5 h. Storage periods could significantly (P < 0.05) influence on embryo mortality (total, early, middle, and late), hatchability of both the total eggs and fertile eggs. The SPIDES treatment had a significant (P < 0.05) impact on a lower embryonic death rate and improved egg hatchability. Eggs stored for 5 days and eggs treated with SPIDES significantly (P < 0.001) shorten hatching time, batch’s 90% hatching time (T 90% H), mean hatching time (MHT), maximal hatching period (MHP), and hatching window (HW). Chick quality was also determined, whereas storing eggs for 5 days and using the SPIDES treatment resulted in enhanced (P < 0.001) chick weight relative to egg weight (CW/EW), activity (AC), and chick quality score (CQS). The residual yolk sac weight (RYSW), unhealed navel (UHN %), and dirty feather (DF%) recorded the lowest (P < 0.001) values compared to long storage periods and control group. Finally, stored for 5 days treated by SPIDES positively affected the hatchability characteristics, the shortening hatching time, and the quality of chicks. Regarding the results, it was confirmed that using the SPIDES treatment to prevent the harmful effects of broiler eggs being stored for an extended period of time is a viable option.

Modulatory Effects of Arctostaphylos uva-urs Extract In Ovo Injected into Broiler Embryos Contaminated by Aflatoxin B1.

Simple SummaryThe poultry industry is of great importance worldwide; however, mycotoxins contamination, especially aflatoxins, has harmful effects on poultry production. Therefore, finding out new strategies to alleviate aflatoxin contamination is an important trend of research. In our study, we focused on the in ovo injection techniques using the methanolic extract of brae beery “Arctostaphylos uva-ursi” (Ar. uu) to modulate the aflatoxinB1 (AFB1) adverse effects in broiler embryos. As a result, 0.1 g of Ar. uu in ovo injection alleviates AFB1 embryotoxicity by enhancing chicks’ physiological responses and optimizing antioxidant status, which is reflected in a low mortality rate and heavier relative weight of the hatched chicks. The in ovo injection of AFB1 + Ar. uu significantly declined AFB1-induced toxicity in embryos and increased broiler chicks embryo’s survival by 62.5%, increased relative embryo weight by ∼65.25% compared to eggs injected with AFB1 alone. Regarding immune responses, the in ovo injection of Ar. uu enhances the embryo’s humoral immune responses and regulates oxidative stress biomarkers. In general, the in ovo injection of Ar. uu modulates broiler chicks’ embryotoxicity caused by AFB1.In ovo injection of nutrients can modulate the embryo’s physiological responses against aflatoxin B1 (AFB1) embryotoxicity. This hypothesis was tested using in ovo injection of Arctostaphylos uva-ursi (Ar. uu.) methanolic extract. The total polyphenols, total flavonoids, total antioxidant capacity, and GC-MS analysis were all assessed in the Ar. uu. methanolic extract. A total of 180 ten-day-old embryonated eggs were distributed into six groups of 30 replicates each. The first group was used as a control (non-injected), and the second, third, fourth, fifth, and sixth groups were injected with 10 µ double-distilled water (DDW), 500 µL methanol, 0.01 g Ar. uu./500 µL methanol, 50 ng AFB1/10 µL DDW, and 50 ng AFB1 in 10 µ DDW + 0.01 g Ar. uu./500 µL methanol, respectively. The relative embryo weight, residual yolk sac weight, tibia length and weight, and survival were recorded. Total and differential leukocytes, oxidative stress, and humoral immune responses were observed. The residual yolk sac was lower (p < 0.05) in the Ar. uu. group than other groups. The embryonic growth (tibia weight and length) was enhanced in AFB1 + Ar. uu.-injected embryos compared with those injected with AFB1 alone. In conclusion, in ovo injection of Arctostaphylos uva-ursi could modulate AFB1-induced toxicity in chicken embryos.

Maternal immune activation in rats induces dysfunction of placental leucine transport and alters fetal brain growth.

Maternal infection during pregnancy increases the offspring risk of developing a variety of neurodevelopmental disorders (NDDs), including schizophrenia. While the mechanisms remain unclear, dysregulation of placental function is implicated.We hypothesised that maternal infection, leading to maternal immune activation and stimulated cytokine production, alters placental and yolk sac amino acid transport, affecting fetal brain development and thus NDD risk. Using a rat model of maternal immune activation induced by the viral mimetic polyinosinic:polycytidylic acid (poly(I:C)), we investigated placental and yolk sac expression of system L amino acid transporter subtypes which transport several essential amino acids including branched-chain amino acids (BCAA), maternal and fetal BCAA concentration, placental 14C-leucine transport activity and associated impacts on fetal growth and development.Poly(I:C) treatment increased acutely maternal IL-6 and TNFα concentration, contrasting with IL-1β. Transcriptional responses for these pro-inflammatory cytokines were found in placenta and yolk sac following poly(I:C) treatment. Placental and yolk sac weights were reduced by poly(I:C) treatment, yet fetal body weight was unaffected, while fetal brain weight was increased. Maternal plasma BCAA concentration was reduced 24 h post-poly(I:C) treatment, yet placental, but not yolk sac, BCAA concentration was increased. Placental and yolk sac gene expression of Slc7a5, Slc7a8 and Slc43a2 encoding LAT1, LAT2 and LAT4 transporter subtypes, respectively, was altered by poly(I:C) treatment. Placental 14C-leucine transport was significantly reduced 24 h post-treatment, contrasting with a significant increase 6 days following poly(I:C) treatment.Maternal immune activation induces dysregulated placental transport of amino acids affecting fetal brain development, and NDD risk potential in offspring.

The effect of different early feeding regimens involving a hydrated nutritious gel on productive performance, immune variables, and intestinal morphology of broiler chickens

The present research aimed to evaluate the effect of early feeding (EF) with a hydrated nutritious gel (HNG) on productive performance, carcass traits, immune variables, and intestinal morphology of broiler chickens. A total of 490 one-day-old Ross 308 broilers were allotted to 5 EF regimens with 7 replicates each. Treatments were as follows: the group deprived of both feed and water during the first 24 hours post-hatch (control); group fed with 2g HNG/bird in chick box and then with 2g HNG + 2g starter feed/bird immediately after placement (T1); group fed with 2g HNG + 2g starter feed/bird in chick box (T2); group fed with 2g HNG/bird in chick box (T3); and the group fed with 2g HNG + 2g starter feed/bird immediately after placement (T4). The results showed that HNG-treated groups had lower relative yolk sac weight compared to the control group (P < 0.05). During the starter period, T2, T3, and T4 groups had significantly (P < 0.05) higher body weight gain (BWG) and feed intake (FI) than the control group. At 24 d of age, the T2 group had the highest BW, differing significantly from those of the control and T1 groups. During the grower period, the T4 group had higher FI than the control group (P < 0.05). Antibody response against infectious bronchitis virus (IBV) was improved in the T1, T2, and T3 groups (P < 0.05). The highest relative leg weight was found in the T2 group. In conclusion, the HNG administration in chick box and/or immediately after placement had beneficial effects on the health and performance of broiler chickens. Highlights Receiving the nutritious gel resulted in significant increments in yolk sac absorption. Early nutrition with the nutritious gel showed positive effects on weight gain and feed intake during the first 10 d post-hatch. On the 25th day after hatch, gel-receiving groups had higher antibody titers against infectious bronchitis virus as compared to the control group.

Effects of in ovo application of resveratrol on hatchability, hatching time, yolk sac weight and chick performance in quail

The purpose of this study was to investigate the effects of in ovo resveratrol in hatching quail eggs on hatching traits, organ weights and chick performance. The eggs were randomly distributed into four groups as non-injected group (PC; Positive control), 0.2 ml saline (NC; Negative control), 0.2 ml solution containing 1 nmol of resveratrol (R1) and 0.2 ml solution containing 4 nmol of resveratrol (R4). Hatchability of set eggs (HSE) and hatchability of fertile eggs (HFE), embryonic mortality (EM), chick hatching time, yolk sac weight (YSW), and chick performance characteristics were investigated. The effects of in ovo resveratrol administration on the HSE were insignificant. HFE decreased significantly with in ovo resveratrol treatment. All injected groups were adversely affected in terms of embryonic deaths. The effect of in ovo resveratrol application on chick hatch weight, and YSW (g, %), chick performance was insignificant. It was observed that in ovo resveratrol treatment had no significant effect on the hatching time, except at 408 h of incubation. As a result, in ovo resveratrol application had a negative effect on hatchability and EM, but did not have affected the hatching time, YSW and chick performance.

Assessment of the Teratogenic Effect of Sulfadoxine-Pyrimethamine on the Chicken Embryo.

Background The sulfadoxine-pyrimethamine combination is a product used in the intermittent preventive treatment (IPT) of malaria in pregnant women in our country. To date, there is very little data on the teratogenic effect of this product. This study proposed to evaluate the teratogenic effect of sulfadoxine-pyrimethamine on chicken embryos. Methods The teratogenic effect of the product was evaluated on chicken embryos at a dose of 1.3 mg/g sulfadoxine and 0.06 mg/g pyrimethamine. The product was injected before the start of incubation and on days 12, 14, 16, and 18 of incubation. One batch received a double injection of the product on days 16 and 18 of incubation. The quality of the hatched chicks was evaluated by the Tona Score followed by the determination of hematological and biochemical parameters. Results From the aforementioned, it appears that the eggs treated with sulfadoxine-pyrimethamine significantly decreased the hatchability rate of the eggs. The chicks obtained were all of very good quality. Apart from a significant decrease in the weight of the chicks of the batch that received the injection twice and a significant increase in the weight of the yolk sac of the chicks of the batch that received the injection on day 16 compared to the control, no variation was obtained. A significant increase in the white blood cell count of the chicks compared to the control was reported in the chicks of the batch injected before incubation and on day 12, as well as a significant increase in the platelet count of the chicks of the batch injected twice. For biochemical parameters, no significant difference was reported in ALT and AST. Conclusion Sulfadoxine-pyrimethamine decreased egg hatch and caused an increase in embryo and chick mortality as well as a loss in relative chick weight and an increase in relative yolk sac weight. More in-depth studies would be needed on sulfadoxine-pyrimethamine teratogenicity and the benefit/risk ratio of this drug during pregnancy.

Effects of in ovo feeding of disaccharide and/or methionine on hatchability, growth performance, blood hematology, and serum antioxidant parameters in geese.

A completely randomized design employing a 2 × 2 factorial experiment was designed in this study to evaluate the effects of in ovo injection of disaccharide (DS) and/or methionine (Met) on hatchability, growth performance, blood hematology, and serum antioxidant parameters in geese. A total of 600 fertilized geese's eggs containing live embryo were randomly assigned into 4 groups with 6 replicates and 25 eggs per replicate. Factors in four groups comprised noninjection, DS injection (25g/L maltose + 25g/L sucrose + 7.5g/L NaCl), Met injection (5g/L Met + 7.5g/L NaCl), or DS plus Met injection (25g/L maltose + 25g/L sucrose + 5g/L Met + 7.5g/L NaCl), respectively. We found that the administration of DS in embryo increased hatching time, yolk sac-free carcass weight, yolk sac-free carcass indexes and decreased assisted hatching ratio, yolk sac weight, yolk sac indexes, but did not affect hatchability and mortality. Moreover, higher body weight and serum glucose concentrations in DS injection group compared with noninjection group were observed on day of hatching. The body weight and average daily gain (ADG) of geese in DS injection group were higher than noninjection group after incubation. In ovo injection of Met increased hatching time and yolk sac-free carcass indexes, but decreased yolk sac indexes. In addition, the strategy of in ovo feeding of Met led to higher body weight, ADG, serum uric acid, glutathione (GSH), and glutathione peroxidase concentrations, as well as lower GSSG/GSH ratio, serum glutathione disulfide (GSSG), and malondialdehyde (MDA) concentrations than the noninjection group on day of hatching. The post-hatching body weight, ADG, serum total protein, albumin, and uric acid concentrations increased, whereas post-hatching serum GSSG and MDA concentrations and GSSG/GSH ratio decreased when injected with Met. In addition, synergistic effects of in ovo injection of DS plus Met on hatching time as well as post-hatching body weight and ADG were observed. Therefore, in ovo injection of DS plus Met was demonstrated to be a way to improve the development of geese during early incubation stages.

Change of zinc mobilization and gene expression of key zinc transport proteins between the yolk sac membrane and liver of duck embryonic developing

Zinc (Zn) deposition in egg yolk is essential for the rapid growth and complete development of the avian embryo. Thus, it is crucial to obtain maximal Zn mobilization at an appropriate time during development in favor of the survival of avian embryos. The aim of this study was to study the developmental change of Zn mobilization and gene expression related to key Zn transport proteins between the yolk sac membrane and embryonic liver from the incubation d 17 (E17) to d 32 (E32) during duck embryonic developing. The weights of duck embryo, embryo without yolk sac, and embryonic liver increased as well as the yolk sac weight decreased linearly (P < 0.0001) when incubation day increased. The Zn concentration in the yolk sac did not change from E17 to E29 and only declined significantly from E29 to E32 of duck embryos, while hepatic Zn level decreased linearly as with the increased incubation time (P < 0.01). When the incubation day increased, the decreased Zn amount in the yolk sac and the increased Zn amount in the embryonic liver were observed (P < 0.0001). The calculated transfer-out rate of Zn in the yolk sac and transfer-in rate of Zn in livers were both increased from E23-26 to E29-32 (P < 0.01). Among E17, E23 and E29, the solute carrier family 39 member (ZIP) of ZIP10, ZIP13, and ZIP14 genes mRNA expressions were increased in yolk sac membrane but were decreased in the embryonic liver, while metallothionein 1 mRNA expression was increased both in the yolk sac membrane and liver (P < 0.05). In conclusion, yolk sac membrane and embryonic liver tissues displayed the similar developmental patterns of Zn mobilization and metallothionein 1 mRNA expression from E17 to E32 during duck embryonic developing. The appropriate time of the maximal rate of Zn mobilization were observed between E29 and E32 of duck embryo, associated with the significant changes of gene expression related to some key Zn transport proteins on E29 in yolk sac membrane and liver tissues.

Effect of egg weight on development, bone morphology, and breast muscle histology of embryos from fast-and slow-growing strains

The present study aimed to determine the impact of egg weight on embryonic development, breast muscle histology, and bone morphology of fast- and slow-growing embryos and chicks. For this purpose, total 192 eggs from fast-(Ross 308) (FG) and slow-growing (Hubbard JA) (SG) broiler breeders were used. Eggs were classified as medium (64 ± 1 g, Megg) and heavy (72 ± 1 g, Hegg) eggs. At 18 days of incubation, egg weight loss, embryo weight, embryo length, breast width and length, yolk sac weight, and bone morphometric parameters were measured and breast muscle histology were studied. The same measurements were repeated on the day of the hatch. Although yolk utilization of FG embryos from Hegg and Megg was similar, SG-Megg embryos were more efficient than SG-Hegg at utilizing of yolk nutrients at 18 days of the embryogenesis and the day of the hatch. On the day of hatch, Hegg chicks were heavier than Megg regardless of the strain. Embryos and chicks from FG-Hegg had more fiber area than those from SG-Hegg whereas embryos from Megg were not influenced by strain. Higher capillary number and capillary to fiber ratio was found in FG-Hegg embryos than those from FG-Megg. At hatch, the FG embryos had wider tibia and shank at 18 days and heavier tibia, femur, and shank compared to SG. Egg weight affected relative bones weight, being chicks from Megg heavier than those from Hegg. Lower tibia ash content was found in Hegg chicks. It is concluded that Hegg may be an advantage for a larger fiber area and capillary density. However, lighter femur, tibia, and shank of Hegg chicks with lower tibia ash content than those from Megg regardless of strain may indicate that heavier eggs could negatively affect bone properties of chicks.

Effect of high eggshell temperature during the early period of incubation on hatchability, hatch time, residual yolk, and first-week broiler performance1

During incubation, temperature is the main environmental condition affecting the hatchability and chick quality. The effect of high temperature after the first week of incubation to hatching has been widely investigated. However, very little is known during the early period of incubation. This study was conducted to investigate the effect of increased eggshell temperature ( EST ) during the first 6 embryonic d of incubation (E) on hatchability, hatch time, and first-week broiler performance. A total of 1,680 hatching eggs were divided randomly into 4 treatment groups were as follows: Control (37.8°C), High EST (38.6°C) from E0 to E3, E3 to E6, and E0 to E6. The EST was maintained at 37.8°C from E6 onward in all groups. Fertile hatchability was significantly better in eggs maintained at the control temperature (37.8°C EST through incubation) and at 38.6°C EST from E0 to E3 (High E0-E3) compared to eggs exposed to an EST of 38.6°C from E3 to E6 (HighE3-E6) and E0 to E6 (HighE0-E6) of incubation ( P < 0.05) due to decreased early embryonic mortality ( P < 0.05). The average hatch time differed among all treatments, with the earliest hatch time for HighE0-E6 followed by the HighE0-E3, HighE3-E6, and Control groups ( P < 0.01). Yolk free body mass ( YFBM ) and residual yolk sac ( RYS ) weight were not significantly affected by high EST (38.6°C) during the first 6 d of incubation. At 7 d of age, the HighE0-E3 and Control groups were found to have greater BW than the other 2 groups ( P < 0.05). No significant difference was found for feed consumption ( FC ), feed conversion ratio ( FCR ), or mortality among the treatments for 7 d ( P > 0.05). These results suggest that compared with the control condition, the exposure of eggs to 38.6°C EST from E0 to E6 or from E3 to E6 of incubation shortened the hatch time but decreased fertile hatchability and the first week BW ( P < 0.05). However, compared with the control temperature, increased EST during the first 3 d of incubation did not impact hatchability, percentage of second-grade chicks and first-week broiler performance ( P > 0.05), but chicks hatched earlier ( P < 0.05).

Research Note: Effects of preincubation and higher initiating incubation temperature of long-term stored hatching eggs on hatchability and day-old chick and yolk sac weight

We studied the effect of increased initial incubation temperature and repeated preincubation of 35-d stored eggs from 46-week-old Ross 308 parental stock on the hatchability and day-old chick and yolk sac weight. Two different temperatures were applied during the first 36 h and they were combined with 4 preincubation treatments during storage. One half of the hatching eggs (2,400) were incubated for the first 36 h at an incubation temperature of 38.3°C, and the second half were incubated at a higher temperature of 39.2°C. Four different preincubations were applied; none, once at the 7th d of hatching egg storage, twice at the 7th and 12th d of storage and 3 times at the 7th, 12th and 19th d of storage. Both preincubation and increased temperature had negative effects on hatchability (P < 0.001). The interaction between these 2 factors was also significant (P < 0.05). These 2 factors also negatively affected early and late embryonic mortality (P < 0.001). However, middle embryonic mortality was not influenced. Live weight, weight of residual yolk sac, and yolk sac proportion were not affected by repeated preincubation nor by increased temperature over the first 36 h of incubation (P > 0.05). A higher initial temperature decreased chick yolk free body mass (P < 0.05). Although neither increased initial temperature in the setter nor repeated preincubation affected one-day-old chick weights, these treatments were not suitable for long-term stored eggs because of decreased hatchability and impairment of one day chick quality expressed as yolk free body mass.

Effects of breeder age and short-term temperature stimulation during incubation on performance, organ weight, and carcass yield in male and female broilers

Birds develop thermoregulatory control during the last days of incubation. Different temperature conditioning programs have been proposed to prepare broiler chicks for post-hatch life. This study aimed to investigate the effects of short-term temperature (STT) stimulation and breeder age on hatching performance, embryo development, yolk absorption, and post-hatch performance of male and female broilers. A 2 × 2 factorial completely randomized design was used, with two breeder ages (30 and 60 wk), two temperature incubation programs (control and STT), and 2,520 eggs per treatment. Eggs were distributed in two large-scale commercial incubators with a capacity of 120,960 eggs. The control group was subjected to a standard single-stage incubation program (37.2-37.4 °C), whereas the STT group was subjected to a temperature increment of 1 °C for 4 h on embryonic days 16, 17, 18, and 19. Embryos were analyzed at 16 and 19 days of incubation, and chicks at hatch. At 19 days of incubation, STT conditioning resulted in lower yolk sac weight in embryos from 60-wk-old breeders and higher relative weight of the gastrointestinal tract in embryos from 30-wk-old breeders. At hatch, males had lower residual yolk weight, females had greater length, and chicks from 60-wk-old breeders subjected to STT had higher body weight and relative weight of the gastrointestinal tract. Eggs from 30-wk-old breeders showed higher fertility and hatchability and lower infertility, mortality, and second-grade chick percentages. Regarding performance, it was found that males had higher body weight from 7 to 42 days of age and higher whole leg yields. Females, on the other hand, had higher fat yields. Breeder age and sex influenced gastrointestinal tract development, carcass yield, and performance. A 1 °C increase in incubation temperature for 4 h from days 16 to 19 of incubation affected yolk absorption and digestive tract development in chicks from 60-wk-old breeders without, however, influencing performance results.