Hatch Weight Research Articles

Comparative growth performance in different Japanese quail lines: The effect of muscle DNA content and fiber morphology

The aim of this study was to investigate the DNA content and morphological characteristics of muscle fibers, and their relation to the growth performance in random bred control (RBC) and heavy weight (HW) Japanese quail lines. The 2 lines were of similar embryo size at 6 and 8 d of incubation; however, HW quail were significantly larger than their counterparts after 10 d of incubation (P < 0.05). The hatch weight of the HW quail line was approximately 1.3-fold higher than the RBC quail line (P < 0.001). After 15 d posthatch, the BW and pectoralis major muscle weight (PMW) exhibited remarkable differences between the 2 quail lines. The RBC line showed a faster rate of increase in PMW (2.7- vs. 2.1-fold) and total DNA mass (2.2- vs. 1.6-fold) between 0 and 4 d posthatch. The HW line exhibited a greater rate of the PMW (33.0- vs. 12.9-fold) and total DNA mass (10.3- vs. 4.0-fold) between 4 and 15 d posthatch than the RBC line. Moreover, the greatest increase in total DNA mass occurred between 0 and 8 d posthatch for the RBC line and 4 to 15 d posthatch for the HW line. These differences in the DNA content indicate a difference in the hypertrophic potential of muscle fibers between the 2 quail lines. The cross-sectional area of muscle fibers was 1.3-fold greater in the HW line compared with the RBC line at 8 d posthatch (158.5 vs. 97.11 μm(2), P < 0.001), and this difference increased with age (over 2.1-fold greater in the HW line). Thus, the most important time windows affecting ultimate body and muscle weights in the RBC and HW quail lines are between 0 to 8 d and 4 to 15 d posthatch, respectively. Rapid muscle growth rate and a greater muscle mass in the HW quail line may be partially due to the hypertrophic potential of muscle fibers, which is characterized by larger fiber size.

EFFECT OF SACCAHAROMYCES CEREVICIAE (INACTIVATED YEAST) ON QUAIL FED RATION CONTAMINATED WITH FUMONISIN B1 MYCOTOXICOSIS.

In this study, 160 day-old, Japanese quail chicks were randomly assigned into four groups, 40 birds of each. The first control group was fed on a basal diet (group1) and the other 3 groups were fed basal diet supplemented with 0.5% yeast, 0.5% yeast + 200mg fumincin-B1/ kg diet and 200mg fumincin-B1/ kg diet, respectively. The results of fumincin-B1(FBI) supplemented group showed a significant on increase in mortality rate, alanine amonotransferase (ALT), aspartate aminotransferase (AST), cholesterol, uric acid and createnine and a decrease in body weight,hatchability, fertility and hatching weight, hematological parameters, serum total proteins, globulins and glutathioneperoxidase (GPx) activity in comparison with the control group. Yeast supplementation was found to alleviate the toxic effects of FB1.

Effect of in ovo ghrelin administration on hatching results and post-hatching performance of broiler chickens

The aim of this study was to investigate the effects of in ovo ghrelin administration on hatching weight, hatchability, and post-hatch performance of broiler chickens. One thousand fifty fertilized eggs were divided into 7 treatments (150 eggs/treatment): treatment C (control, intact without injection), treatment G50d5 (50ng ghrelin/egg at day 5), treatment G100d5 (100ng ghrelin/egg at day 5), treatment G50d10 (50ng ghrelin/egg at day 10), treatment G100d10 (100ng ghrelin/egg at day 10), treatment G0d5 (vehicle without ghrelin at day 5), and treatment G0d10 (vehicle without ghrelin at day 10). Hatchability in all of the injected treatments was lower than C (P<0.01), indicating an influence of injection that was augmented. Hatchability of treatments G50d10 and G100d10 were greater than treatment G0d10 (P<0.01). Hatching weight was greater in all injected treatments than intact. Healthy hatched chicks from each treatment were allocated to 21 floor pens with three replicate pens pretreatment and 7 chicks per pen. Chicks were fed common starter and grower diets, and BW and feed intake were recorded weekly. At day 42 post-hatch, one chick from each replicate that had BW close to the mean was selected. Blood samples were collected, and, then, chicks were harvested to evaluate carcass quality. There was a decrease in feed intake and feed conversion ratio (FCR) for treatments subjected to in ovo ghrelin (P<0.01). There were increases in thigh, breast, and gizzard weights, and abdominal fat deposition in 42-d old chickens on treatment G100d10 (P<0.01). The results indicated that in ovo administration of exogenous ghrelin can improve hatching weight and post-hatch performance, and in ovo administration of 100ng ghrelin/egg, can be efficient in increasing breast and thigh yields. When suitable hatching weight, performance, and carcass yield are the main focus of broiler production, in ovo injection of 50ng ghrelin/egg can be beneficial.

Crecimiento juvenil y parámetros fisiológicos en pollos exóticos y Nigerianos durante la estación seca

En este estudio se evaluó el crecimiento juvenil y perfil de hormonas plasmáticas en cepas exóticas de broilers y pollos nigerianos, empleando un total de 1200 huevos eclosionados, 300 de cada una de las cuatro líneas estudiadas. Las líneas estudiadas fueron Pollo Indígena Nigeriano (NIC) y las líneas Arbor Acre, Hubbard y Marshall. Semanalmente se controló el peso y se tomaron muestras de sangre a la eclosión (1 día) y semanas 1, 2, 3 y 4 de vida para la determinación de triyodotironina (T3) y corticosterona. Los pollos fueron distribuidos al azar en cuatro jaulas de cría para evaluación del crecimiento en 28 días. Los resultados mostraron que el peso en las líneas de broilers fueron mayores que en los pollos NIC en todo el periodo. No hubo diferencias significativas en los niveles de T3 a 1 día de edad y semana 1 hasta el final de la fase de crecimiento. Los niveles de corticosterona no variaron en el día 1, pero se hicieron diferentes desde la semana 1. Los niveles de T3 no fueron diferentes en la primera semana de crecimiento. En la segunda semana de crecimiento hubo diferencias entre las cuatro líneas estudiadas. El nivel en NIC fue conmparable al de las líneas Arbor Acre y Marshall. El nivel en la línea Hubbard fue inferior al de NIC, Arbor Acre y Marshall. En la tercera semana de crecimiento, el nivel en NIC fue similar al de Marshall y superior al de Hubbard y Arbor Acre. El estudio demostró que a la eclosión, no hubo diferencias en la tasa metabólica y nivel de estrés entre las cepas estudiadas como se comprueba por los niveles de T3 y corticosterona respectivamente. El peso de los pollos de un día y el peso en las siguientes semanas fueron más bajos en los pollos NIC. Sin embargo, las diferencias en los parámetros fisiológicos y metabólicos en el crecimiento juvenil, pueden ser parcialmente debidas a las diferencias genéticas.

Crossbreeding and Reciprocal Effect on Egg Weight, Hatch Weight and Growth Pattern and the Interrelationships Between These Traits in Three Genetic Groups of Native Chickens of Nigeria

Crossbreeding and Reciprocal Effect on Egg Weight, Hatch Weight and Growth Pattern and the Interrelationships Between These Traits in Three Genetic Groups of Native Chickens of Nigeria

Effects of ultrasonic waves on eggshell strength and hatchability of layer-type breeder eggs

Two trials were conducted to investigate the effects of exposing layer-type breeder eggs before incubation to ultrasonic waves (ULT). Eggs were subjected to ULT of 117 volts at 40 kHz for up to 15 minutes. Eggshell breaking force (EBF), hatchability and chick hatching weight (CHW) of Balady breeder eggs (Trial 1), and egg weight loss, embryo weight, hatchability and CHW of Leghorn hen eggs (Trial 2) were measured. In Trial 1 the eggs were subjected to seven treatments: non-dipped (control), and dipped for 5, 10 and 15 minutes in a water bath (W5, W10 and W15) or a ULT bath (ULT5, ULT10 and ULT15). In Trial 2 the eggs were subjected to four treatments, a control (ULT0) and the ultrasonic treatments, ULT5, ULT10 and ULT15. In treatments ULT10 and ULT15 the EBF of Balady eggs was significantly reduced while the hatchability of the Balady and Leghorn eggs was significantly reduced by the ULT15 and W15 treatments, compared with the control. Orthogonal contrast (control vs. ULT) indicated that ULT exposure of eggs reduced their EBF significantly. Percentage egg weight loss, embryo weight and CHW was not affected by the treatments. It was concluded that exposure of eggs to ULT of 117 volts at 40 kHz for 15 minutes reduced EBF and hatchability of layer-type breeder eggs without altering egg weight loss, embryo weight or CHW.

Evaluation of carryover effects of dietary lysine intake by Cobb 500 broiler breeder hens

Two experiments were conducted to examine the progeny performance of broiler breeder (BB) hens fed diets differing in digestible lysine (dLys). A total of 240 Cobb 500 BB pullets and 40 cockerels, 20 wk of age, were used for each of 2 experiments. In experiment 1, treatment diets were fed from 35 to 45 wk of age. Treatment 1 and 2 diets were formulated with common feed ingredients and BB had dLys daily intakes of 1,200 (IDL-1,200) and 1,010 mg/hen per d (ID-1,010), respectively. Treatments 3 and 4 were composed of semipurified diets formulated to dLys intakes of 1,010 (SPL-1,010) and 600 mg/hen per d (SP-600), respectively. In experiment 1, chick weight at hatch was lower (P < 0.05) for those that came from the SP-600 and SPL-1,010-fed hens, but 42 and 56 d BW was similar for all treatments. Improvements (P < 0.10) in feed conversion ratio were seen at 42 and 56 d for chicks from ID-1,010-fed hens compared with IDL-1,200 hens. For experiment 2, diets were fed to BB hens from 24 to 42 wk of age. Treatment 1 was composed of corn-soybean meal and formulated to a dLys intake of 1,000 mg/hen per d (CS-1,000). Treatments 2, 3, and 4 had inclusion of 25% distillers dried grains with solubles (DDGS) with dLys intake levels of 1,000 (DDGS-1,000), 800 (DDGS-800), and 600 (DDGS-600) mg/hen per d, respectively. Progeny performance was evaluated from eggs collected at wk 26, 31, and 36. Chick hatch weight was similar for all 3 hatches. Chicks from 26-wk-old BB hens and fed DDGS-600 diets resulted in lower (P < 0.05) BW, carcass weight, and breast weight, and higher (P < 0.05) back half (drumsticks and thighs) yield, at 42 d of age. Growout studies performed on eggs laid during wk 31 and 36 revealed no effect on growth or carcass parameters. In conclusion, the results from experiments 1 and 2 may not be comparable, and therefore, the impact on progeny performance needs to be further evaluated.

Effect of Width and Depth of Bell Drinker and Sex on Fattening Performance and Carcass Characteristics of Pekin Ducks

Summary The aim of this study was to determine the effects of width and depth of bell drinker and sex on fattening performance and carcass characteristics of Pekin ducks. A total of sixty male and sixty female ducklings (Star 53 H.Y., Grimaud Freres) were used. Each sex group was randomly allocated into two bell drinker groups (narrow bell drinker with 47 mm water depth and 48 mm water width and wide bell drinker with 78 mm water depth and 90 mm water width) each of 30 ducklings. Groups were located in floor pens of 170 x 94 cm width x length, each of 6 chicks, in a naturally ventilated house. Sex affected the hatching weight (P<0.01), total body weight gain (P<0.001), feed intake (d 22 to 42 and d 1 to 42, P<0.05), feed conversion ratio (d 1 to 21, P<0.05), slaughter weight (P<0.001) and percentages of hot carcass (P<0.05). Wide bell drinker increased the body weight gain (d 22 to 42 and d 1 to 42, P<0.001), feed efficiency (d 22 to 42 and d 1 to 42, P<0.01), slaughter weight (P<0.001) and percentages of breast and wings (P<0.01), however decreased the percentages of skin subcutaneous fat (P<0.01). More width and depth bell drinker was positively contributed to the fattening performance in rearing of Pekin ducks.

Effects of short term exposure of layer-type breeder eggs to magnetic field on hatchability and hatching parameters

Two trials were conducted to investigate the effects of short term exposure of layer-type breeder eggs to magnetic field (MF) of 7.5 Gauss (0.75 mT) at 50 Hz, for 0, 20, 40 and 60 min before incubation on the characteristics of egg contents, egg weight loss, embryonic growth and hatching time (Trial 1) and hatchability of eggs (Trials 1 and 2). 384 and 240 Leghorn and Baladi eggs were used in trials 1 and 2, respectively. Treatments were replicated 4 times in the two trials. Exposing Leghorn eggs to MF did not influence weight of egg contents, eggshell thickness, albumen and yolk heights, embryo weight, hatching time and hatchability of eggs. Eggs exposed to MF for 40 and 60 min had higher weight loss percentage and chick hatching weight when expressed on the basis of absolute value. It can be concluded that short term exposure of layer-type breeder eggs to MF of 7.5 Gauss (0.75 mT) at 50 Hz, for up to 60 min before incubation did not influence the characteristics of egg contents, embryonic growth, hatching time, and hatchability of eggs. MF exposure of eggs for 40 and 60 min increased egg weight loss during incubation, and chick weight at hatch day. Key words: Magnetic field, layer eggs, embryonic growth, hatchability.

Effect of breed, age and storage period on egg weight, egg weight loss and chick weight of commercial broiler breeders raised in Saudi Arabia

A total of 1350 hatching eggs were obtained from commercial broiler breeders Cobb, Ross 308 and Arbor Acres at 30–35, 40–45 and 50–55weeks of age, 450 eggs for each breed and 150 eggs for each breed age. Eggs for each age were randomly divided into three groups, 50 eggs in each, stored either for 0, 7 or 14days, individually weighed before and after storage and incubated following usual hatchery practices. Individual chick weight was recorded at hatch and chick weight percent of fresh egg weight was calculated and data were statistically analyzed. Ross, young breeders and eggs stored for 14days had the lowest (P⩽0.05) egg weight whereas Arbor Acres, young breeders and hatching eggs stored for 14days showed the highest (P⩽0.05) egg weight loss percent. Cobb, old breeders and fresh hatching eggs had the highest (P⩽0.05) chick weight while Ross, old breeders and fresh hatching eggs showed the highest (P⩽0.05) chick weight percent of fresh egg weight.From the results of the study we conclude that there are significant breeds’ differences with respect to all studied traits. Arbor Acres was inferior to Cobb and Ross in most studied traits. The results also showed that advancing breeders’ age had a positive effect whereas prolonged egg storage period had a negative effect upon all studied traits.

MODIFIKASI PENETASAN TELUR BURUNG MALEO GUNUNG (Aepypodius arfakianus) UNTUK MENINGKATKAN DAYA TETAS

&lt;p&gt;his research aims to determine the physical characteristics and quality of eggs of mountain Maleo bird (Aepypodius arfakianus) in Papua and to determine hatching rate by using some modified hatching method to improve&lt;br /&gt;the egg’s hatchability. This research used observation method to analyze variable egg hatching, temperature and humidity. There were three experiments of hatching method, which were semi-natural hatching outside of the habitat&lt;br /&gt;(ex-situ), hatching by using soil and serasah as the media, and hatching by using electric shelves as the media. Observation data of natural hatching showed that the temperature inside of the nest was about 30-35oC with humidity&lt;br /&gt;of 70-90%. The variables measured were embryo durability or fertility, hatchability, period of incubation, hatch weight, and embryo mortality. The data were analyzed using descriptive statistics and correlations for some data required and was presented as mean values and standard deviation (SD). Hatching using electric shelves as the media showed the best result. Length of incubation, egg fertility, hatchability, embryo mortality and hatch weight were 40.14±0.69 days,&lt;br /&gt;90.00%, 77.78%, 22.22%, 112.94±7.84 g, respectively; those of ex-situ modification were 47.50±0.71 days, 80%, 25%, 75%, 109.05±2.33 g, respectively; and those of soil and serasah media were 41.33±0.58 days, 90%, 33.33%, 66.67%, 113.33±5.05 g, respectively. Hatching modifications using electric shelves improves the quality of hatching, shorten the&lt;br /&gt;period of incubation, and reduced the mortality.&lt;/p&gt;&lt;p&gt;(Keywords: Mountain Maleo (Aepypodius arfakianus), Hatching modification, Hatchability)&lt;br /&gt;&lt;br /&gt;&lt;/p&gt;

Temperature-mediated trade-offs and changes in life-history integration in two slipper limpets (Gastropoda: Calyptraeidae) with planktotrophic development

Intraspecific variation in egg size and hatching size, and the genetic and environmental trade-offs that contribute to variation, are the basis of the evolution of life histories. The present study examined both univariate and multivariate temperature-mediated plasticity of life-history traits, as well as temperature-mediated trade-offs in egg size and clutch size, in two planktotrophic species of marine slipper limpets, Crepidula. Previous work with two species of Crepidula with large eggs and lecithotrophic development has shown a significant effect of temperature on egg size and hatching size. To further examine the effect of temperature on egg size in Crepidula, the effects of temperature on egg size and hatching size, as well as the possible trade-offs with other the life-history features, were examined for two planktotrophic species: Crepidula incurva and Crepidula cf. marginalis. Fieldcollected juveniles were raised at 23 or 28 °C and egg size, hatching size, capsules/brood, eggs/capsule, time to hatch, interbrood interval, and final body weight were recorded. Consistent with results for the lecithotrophic Crepidula, egg size and hatching size decreased with temperature in the planktotrophic species. The affects of maternal identity and individual brood account for more than half of the intraspecific variation in egg size and hatching size. Temperature also showed a significant effect on reproductive rate, with time to hatch and interbrood interval both decreasing with increasing temperature. However, temperature had contrasting effects on the number of offspring. Crepidula cf. marginalis has significantly more eggs/capsule and therefore more eggs per brood at 28 °C compared to 23 °C, although capsules/brood did not vary with temperature. Crepidula incurva, on the other hand, produced significantly more capsules/brood and more eggs per brood at the lower temperature, whereas the number of eggs/capsule did not vary with temperature. The phenotypic variance‐covariance matrix of life-history variables showed a greater response to temperature in C. incurva than in C. cf. marginalis, and temperature induced trade-offs between offspring size and number differ between the species. These differences suggest that temperature changes as a result of seasonal upwelling along the coast of Panama will effect the reproduction and evolution of life histories of these two co-occurring species differently. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, , ••‐••. ADDITIONAL KEYWORDS: adaptive phenotypic plasticity ‐ phenotypic covariance ‐ P-matrix ‐ temperature-size rule.

In ovo leptin administration affects hepatic lipid metabolism and microRNA expression in newly hatched broiler chickens

BackgroundA leptin-like immunoreactive substance has been found in chicken eggs and has been implicated in serving as a maternal signal to program offspring growth and metabolism. In the present study, we investigated the effects of in ovo leptin administration on hatch weight, serum and hepatic concentrations of metabolites and hormones, as well as on the expression of genes involved in hepatic lipid metabolism and the predicted microRNAs (miRNAs) targeting the affected genes. To this end we injected fertile eggs with either 0.5 μg of recombinant murine leptin or vehicle (PBS) before incubation.ResultsPrenatally leptin-exposed chicks showed lower hatch weight, but higher liver weight relative to the body weight, compared to the control group. In ovo leptin treatment increased the hepatic content and serum concentration of leptin in newly hatched chickens. The hepatic contents of triglycerides (TG) and total cholesterol (Tch) were decreased, whereas the serum levels of TG, Tch and apolipoprotein B (ApoB) were increased. The hepatic mRNA expression of sterol regulator element binding protein 1 (SREBP-1c), SREBP-2, hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) and cholesterol 7α-hydroxylase 1 (CYP7A1) was significantly up-regulated, as was the protein content of both SREBP-1c and SREBP-2 in hepatic nuclear extracts of leptin-treated chickens. Moreover, out of 12 miRNAs targeting SREBP-1c and/or HMGCR, five were significantly up-regulated in liver of leptin-treated chicks, including gga-miR-200b and gga-miR-429, which target both SREBP-1c and HMGCR.ConclusionsThese results suggest that leptin in ovo decreases hatch weight, and modifies hepatic leptin secretion and lipid metabolism in newly hatched broiler chickens, possibly via microRNA-mediated gene regulation.

The effects of in-ovo injection of glucose on hatchability, hatching weight and subsequent performance of newly-hatched chicks

This experiment was conducted to determine the effects of an in-ovo injection of glucose on hatchability, weight and subsequent performances of newly-hatched chickens. The 720 fertile eggs used in this experiment were obtained from a Cobb-500 broiler breeder flock of 28 weeks of age. Treatments were the following: 1) control group (withou- injection), 2) group injected with 0.5 ml deionized water (sham group), 3) group injected with 0.5 ml glucose 15% in deionized water, 4) group injected with 0.5 ml glucose 20% in deionized water and 5) group injected with 0.5 ml glucose 25% in deionized water. There werh four replicates per treatment and 36 eggs per replicate. The experimental design was a completely randomized design. Upon hatch, hatchability and weight of newly-hatched chicks were measured, and 20 chicks per replicate were transferred to an experimental house and reared for 42 days. Live weight and feed intakeswere measured for each experimental unit at 21 and 42 days of age and then weight gai, and feed conversion ratio were calculated. The results of the study indicate that group that received glucose at 15%, 20% and 25% had significantly higher hatching weight as compared with the control and the sham groups,tbut,eggs injected in ovo had significantly lower hatchability than the controls (p < 0.01). Also, there were no significant treatment effects on feed intake between 0 and 21 days post-hatch. Chicks that received in-ovo injection of glucose haddbetter feed intake, weight gain and feed conversion ratio compared with chicks hatched from the control and the sham groups. The obtained Data suggest that in-ovo injection may increase weight and improve the performancs of newly-hatched chickens.

Two SNP in STAT5B gene and their association with breeding value of growth and egg production traits in Mazandaran Indigenous Chicken

STAT5A/B proteins are the important modulators of growth hormone, growth hormone receptor, IGF-I, prolactin and insulin signaling pathway, which are involved in growth and reproduction. Knowledge of genetic markers in such candidate genes and their association with economical traits, probably make breeding plans more efficient through MAS programs. The aim of the current study was to investigate the possible association of two SNP in chicken STAT5B gene with breeding value of growth and reproductive traits. Total of 205 individuals from breeding station of Mazandaran Indigenous Chicken were selected randomly and they were genotyped for two SNPs of C4535156T and G4533675C using PCR-RFLP technique and HhaI and RsaI restriction enzymes respectively. To estimate breeding value of the growth and reproductive traits, phenotypic information of 18 successive generations of selection in breeding station of Mazandaran Indigenous Chicken (north of Iran) was analyzed using a univariate animal model in ASREML procedure. Finally, marker-trait association analyses were performed using estimated breeding value of the traits, as dependent variable, in GLM procedure of SAS 9.1. Two alleles and three genotypes were identified for each SNP. Significant associations between C4535156T SNP with breeding value of body weight at hatch and between G4533675C SNP with breeding value of first egg weight were found. We can conclude that two SNPs in STAT5B gene are promising markers for future use in selection to increase body weight at hatch and first egg weight.

In ovo leptin administration inhibits chorioallantoic membrane angiogenesis in female chicken embryos through the STAT3-mediated vascular endothelial growth factor (VEGF) pathway

Previous studies indicate that leptin regulates placental angiogenesis and fetal growth in mammals and that in ovo leptin administration affects embryonic development and hatch weight in the chicken. To test the hypothesis that leptin affects embryonic growth through modifying chorioallantoic membrane (CAM) angiogenesis, we injected 0.5 μg of recombinant murine leptin into the albumen of fertilized eggs before incubation. On embryonic day 12 (E12), the number and the total area of blood vessels on CAM were measured, and expression of genes involved in angiogenesis was quantitated to show the possible mechanisms. Leptin in ovo administration decreased (P < 0.05) both the total area of blood vessels and the number of small-sized capillaries on CAM of E12 female chicken embryos, which coincided with significantly decreased (P < 0.05) embryo weight on E12 and BW at hatching. Vascular endothelial growth factor (VEGF) and inducible and endothelial nitric oxide synthases (iNOS and eNOS) were all downregulated (P < 0.05) in CAM both at the mRNA and protein/activity levels with reduced (P < 0.05) nitric oxide (NO) concentration in chorioallantoic fluid of female embryos. Furthermore, signal transducer and activator of transcription-3 (STAT3) was found to be diminished (P < 0.05) both at the mRNA and protein levels and associated with decreased (P < 0.05) binding of STAT3 to VEGF promotor in the CAM of leptin-treated E12 female embryos. These data suggest that in ovo leptin administration affects CAM angiogenesis and embryo growth in female chicken embryos, probably through STAT3-mediated VEGF/NO pathways.

Effects of dietary crude protein levels on development, antioxidant status, and total midgut protease activity of honey bee (Apis mellifera ligustica)

The effects of different levels of dietary crude protein on the development, antioxidant enzymatic activity, and total midgut protease activity of honey bees were investigated in the study. A total of 30 colonies of bees with sister queens were used in the test. Dietary treatments were pure rape pollen (Control) and pollen substitutes (PS) with crude protein (CP) levels at 15%, 20%, 25%, 30%, and 35% (designated as PS15, PS20, PS25, PS30, and PS35), respectively. We compared the effects of these diets on honey bees by measuring diet consumption, bee development (egg hatch, pupation success, and pupal weight), and the protein content of emergent adult bees, their antioxidant status and the activity of their midgut digestive proteases. Bees consumed significantly more (P < 0.001) natural pollen than any PS, and bees fed PS had similar diet consumption over the entire experimental period. However, the total protein intake was varied (P < 0.05). PS with a protein level about 30% was recognized as excellent quality diet for maximum body weight, highest protein content and antioxidant enzymatic activity, and PS with a protein rate about 35% exerted the greatest effect on increasing percentage of hatch and percentage of pupation. All these results indicate that PS appeared to be a valuable proteinaceous food approximated to the pollen, and 30∼35% of dietary protein level was optimal to maintain the colony development.

Quantitative trait loci underlying hatching weight and growth traits in an F2 intercross between two strains of Japanese quail

A three-generation resource population was developed using two distinct Japanese quail strains, wild and white, to map quantitative trait loci underlying hatching weight and growth traits. Eight pairs of white and wild birds were crossed reciprocally and 34 F1 birds were produced. The F1 birds were intercrossed to generate 422 F2 offspring. All of the animals from three generations (472 birds) were genotyped for eight microsatellite markers on chromosome 1. Liveweight data from hatch to 5 weeks of age were collected on the F2 birds. Quantitative trait loci (QTL) analysis was conducted applying the line-cross model and the least-squares interval mapping approach. The results indicated QTL affecting hatching weight and several growth related traits on chromosome 1. The F2 phenotypic variance explained by the detected additive QTL effects ranged from 1.0 to 3.7 for different traits. Modelling both additive and dominance QTL effects revealed additional QTL with significant dominance mode of action affecting pre-slaughter weight. However, there was no evidence for imprinting (parent-of-origin) effects. The variance due to the reciprocal cross effect ranged between 3.0 and 19.1% for weight at 1 week of age and hatching weight, respectively.

Effects of hen production cycle and egg weight on egg quality and composition, hatchability, duckling quality, and first-week body weight in Pekin ducks

This study was conducted to determine the effect of hen production cycle (HPC) and the effect of egg weight (EW) at the same egg production level on egg quality, egg composition, hatchability, duckling quality, and first-week BW in Pekin ducks. For HPC, hatching eggs were obtained from different Pekin-duck breeder flocks, aged 31 wk for the first production cycle (HPC1) and 78 wk for the second production cycle (HPC2). For EW, there were 3 categories: heavy (H), medium (M), and light (L). Ten eggs from each HPC and EW group were analyzed for the determination of egg quality, and albumen and yolk compositions. Ninety eggs from each HPC and EW group were incubated for the determination of hatchability, and duckling weight and quality. After quality scoring, 20 ducklings (10 male and 10 female) from each group were weighed, and reared to 1 wk of age in a brooder machine to determine relative growth (RG). The results showed that the albumen index; Haugh unit; shell percentage; yolk moisture, ash, protein, lipids, and triglycerides; albumen moisture, ash, and protein; yolk fatty acid contents; hatching weight; duckling weights at 1 wk of age; and RG were significantly affected by HPC. Egg weight affected shell thickness, yolk and albumen indices, Haugh unit, yolk and albumen percentages, yolk to albumen ratio, shell percentage, yolk fatty acid content, hatching weight, duckling weight at 1 wk of age, and RG.

English

&nbsp; In this&nbsp;study,&nbsp;insulin-like growth factor binding protein 2 (IGFBP-2) and&nbsp;signal transducers activators of transcription 5b (STAT5b)&nbsp;gene were studied as candidate gene associated with body weight and reproductive traits of the Jinghai Yellow chicken. Single nucleotide polymorphisms (SNPs) of the IGFBP-2 and STAT5b genes were examined in both Jinghai Yellow chicken and three reference chicken populations by PCR-SSCP. Two SNPs (T3746TG and CC3753TT) were detected in the IGFBP-2 gene. One SNP (C8066T) was observed in the STAT5b gene. For primer 1, the general linear model analysis showed that Jinghai yellow chickens with FF genotypes had significant effect on hatch weight, egg weight at 300 days and body weight at 300 days than those of the EF genotype and had significant effect on body weight at 8 weeks of age than those of the EE genotype (P&nbsp;&lt;&nbsp;0.05). For primer 2, Jinghai yellow chickens with CT genotype had significant effect on hatch weight and age at first egg than CC genotype and TT genotype respectively (P&nbsp;&lt;&nbsp;0.05). SNPs in both IGFBP-2 and STAT5b genes had significant effect on body weight and reproductive traits of the Jinghai yellow chicken than those with either SNP alone. These&nbsp;SNPs&nbsp;may&nbsp;be served as a potential genetic marker for growth and reproduction traits evaluation of the Jinghai yellow chicken. &nbsp; Key words:&nbsp;Jinghai Yellow chicken, IGFBP-2 gene, STAT5b gene, economic traits, polymorphism.