Effects of Chromium Propionate on Egg Production,Egg Quality,Plasma Biochemical Parameters,and Egg Chromium Deposition in Late-Phase Laying Hens

This study was conducted to investigate the effects of chromium propionate on egg production, egg quality, plasma biochemical parameters and egg chromium deposition in late-phase laying hens. Four hundred thirty-two 60-weeks old laying hens were divided into four groups of 108 birds per group according to egg production. The dietary treatments consisted of the basal diet adding with 0, 200, 400, and 600 μg/kg chromium as chromium propionate. All laying hens were given feed and water ad libitum for 8 weeks. The addition of 400 μg/kg Cr as chromium propionate increased egg production (P?<?0.01) during the later 4 weeks, but decreased albumen height, yolk color score, and Haugh unit of eggs. Six hundred micrograms per kilogram Cr as chromium propionate supplementation improved shell thickness (P?<?0.05). 200 μg/kg Cr as chromium propionate supplementation decreased the uric acid concentration by 31 % (P?<?0.05). However, supplemental Cr did not affect the egg chromium deposition of hens (P?>?0.05). These data indicated that feeding of late-phase laying hens with chromium propionate could improve egg production, increase eggshell thickness, but do not result in abnormal levels of chromium deposition in eggs.     

Morphological Features and Hatching Patterns of Eggs in Acartia Steueri (Crustacea, Copepoda) from Sagami Bay, Japan

Morphology, production rate and hatching success of the eggs spawned by Acartia steueri from Sagami Bay, Japan were examined from November 2000 to December 2001. A. steueri produced two morphological types of egg. One with a smooth surface (smooth egg) and the other with branched spines on the envelope (spiny egg). Abundance of adult A. steueri increased from April to June 2001, and then decreased from July 2001. Adult A. steueri were low in abundance between August and October 2001, then increased in November 2001. Smooth eggs were produced through out the study period, while spiny eggs were produced during restricted periods from March to July 2001. Six of thirteen females produced both smooth and spiny eggs within 24 h. All the smooth eggs hatched within 48 h, like the so-called subitaneous eggs. Spiny eggs that did not hatch within the time determined by the Bělehrádek's temperature function of egg development time plus 24 h were categorized as diapausing eggs. In the present study, A. steueri seems to survive by utilizing egg dormancy during the period of environmental adversity, and produced two physiologically different types of eggs. This may be why A. steueri dominants in temperate coastal waters where environmental conditions vary drastically.     

Identification of quantitative trait loci associated with egg quality, egg production, and body weight in an F2 resource population of chickens

Egg production and egg quality are complex sex-limited traits that may benefit from the implementation of marker-assisted selection. The primary objective of the current study was to identify quantitative trait loci (QTL) associated with egg traits, egg production, and body weight in a chicken resource population. Layer (White Leghorn hens) and broiler (Cobb-Cobb roosters) lines were crossed to generate an F2 population of 508 hens over seven hatches. Phenotypes for 29 traits (weekly body weight from hatch to 6 weeks, egg traits including egg, albumen, yolk, and shell weight, shell thickness, shell puncture score, percentage of shell, and egg shell colour at 35 and 55 weeks of age, as well as egg production between 16 and 55 weeks of age) were measured in hens of the resource population. Genotypes of 120 microsatellite markers on 28 autosomal groups were determined, and interval mapping was conducted to identify putative QTL. Eleven QTL tests representing two regions on chromosomes 2 and 4 surpassed the 5% genome-wise significance threshold. These QTL influenced egg colour, egg and albumen weight, percent shell, body weight, and egg production. The chromosome 4 QTL region is consistent with multiple QTL studies that define chromosome 4 as a critical region significantly associated with a variety of traits across multiple resource populations. An additional 64 QTL tests surpassed the 5% chromosome-wise significance threshold.     

微卫星座位与丝羽乌骨鸡蛋用系开产性状相关分析

采用多重PCR扩增结合荧光标记全自动电泳检测技术, 对鸡基因组1号染色体和Z染色体上20个微卫星座位与丝羽乌骨鸡BM、BF两个蛋用新品系180个个体的开产性状进行相关性分析。结果表明: 位于1号染色体上的MCW0068、MCW0200与开产蛋重相关显著(P<0.05); 位于1号染色体上的MCW0068、MCW0208和位于Z染色体上的MCW0128与开产体重相关显著(P<0.05); 而位于Z染色体上的MCW0154与开产体重相关极显著(P<0.01)。     

Comparative localization of chicken five functional genes and three microsatellites on quail mitotic chromosomes by two-color FISH hybridization

To localize chicken genes and microsatellites, we used heterologous two-color FISH and chicken chromosome specific BAC clones. All BAC clones were verified by PCR. An analysis of the results has shown that maf gene forms one linkage group with the mc1r gene (CJA11), aldh1a1 forms one linkage group with the igvps gene (CJA15), pno forms one linkage group with the acaca gene (CJA19), fzf forms one linkage group with the bmp7 gene (CJA20), and cw01 forms one linkage group with the ubap2w gene (CJAW). Microsatellite ADL0254 was localized jointly with the insr gene (CJA28), and LEI0342 and MCW0330 microsatellites were localized jointly with the hspa5 gene (CJA17). If we consider that the nomenclature of quail chromosomes is the same as in chickens, their localization will correspond to the following chromosomes: CJA11 (maf), 15 (aldh1a1), 19 (pno), 20 (fzf), and W (cw01). The microsatellite ADL0254 turned out to be located on the same microchromosome as the insr gene (CJA 28), while microsatellites LEI0342 and MCW0330 were found to be in the same linkage group with the hspa5 gene (CJA17). The same work was also carried out on the chicken genome. Different results were obtained. The localization of the BAC clones containing the cw01 and fzf genes and the MCW0330 microsatellite was confirmed completely; they are located on GGAW, 20, and 17 chromosomes, respectively. Microsatellites ADL0254 and LEI0342 were each revealed to have two sites, whereas the localization of the remaining genes (maf, aldh1a1, and pno) on the GGA11, GGA15, and GGA19 chromosomes turned out to be untrue and needs further study.     

Identification of haplotypes in promoter of prolactin gene and their effect on egg production and quality traits in layer chicken

Expression of prolactin hormone is a crucial event in regulating egg production in chickens for which promoter plays the vital role in expressing the prolactin gene. The objective of the present study was to identify haplotypes in the prolactin promoter and their effects on egg production and egg quality traits in White Leghorn chicken. Single stranded conformation polymorphism followed by sequencing was conducted to explore polymorphism at 561 bp promoter of prolactin gene. The effect of haplotype combinations on egg production and quality traits were estimated following general linear model technique. The expression of prolactin by different haplogroups was quantified by qPCR. Total 28 haplotypes were found in White Leghorn chicken of which h1 haplotype possessed the highest frequency of 0.46 and h8, h14, h16, h25, h26, and h28 haplotypes had the lowest frequency (0.1%). The egg production up to 52 and 64 weeks of age were found to be significantly (p < 0.05) associated with haplotype combinations where the highest 52-w (52 weeks) egg production was found in animals with h1/h22 combination and the lowest production was observed in the birds with h1/h2 haplogroup. The haplotype combinations had the significant effect (p < 0.05) on Haugh Unit, yolk index and albumen weight at 40 weeks of age; Haugh Unit and albumen weight at 52 weeks of age and Haugh unit, yolk weight and yolk percentage at 64 weeks of age. The prolactin expression in h1/h22 birds was found to be the lowest and in h1/h5 birds to be the highest. The prolactin expression showed significant effect on 52-w egg production and albumin weight at 52 weeks age. In conclusion, it may be stated that the prolactin promoter was highly polymorphic and had the significant association with egg production and quality traits in White Leghorn chicken.     

Performance,Egg Quality Traits,and Serum Metabolite Concentrations of Laying Hens Affected by Dietary Supplemental Chromium Picolinate and Vitamin C Under a Heat-Stress Condition

A 3?×?2 factorial experiment consisting three levels (0, 200, and 400 μg/kg) of chromium (chromium picolinate) and two levels (0 and 250 mg/kg) of vitamin C was employed to evaluate the effects of these dietary supplements on performance, egg quality traits, and serum biochemical parameters of heat-stressed laying hens (Lohmann LSL-Lite) from 66 to 74 weeks of age. Feed intake increased when birds were given either 400 μg/kg chromium or 250 mg/kg vitamin C (P?<?0.05), but the birds that received both chromium and vitamin C consumed feed similar to those that received only chromium. Dietary treatments had no effect on egg production, egg mass, egg volume, feed conversion ratio, and body mass (P?>?0.05). The birds that fed on diet with chromium or vitamin C produced eggs with higher shell mass and thickness compared to the control. Both eggshell mass and thickness decreased when vitamin C and chromium were supplemented simultaneously, and birds given the diet supplemented with 400 μg/kg chromium and 250 mg/kg vitamin C had eggshell mass and thickness similar to those of the control group. The serum concentration of chromium increased due to increasing level of dietary chromium (P?<?0.05). The birds that received diet with chromium and vitamin C had higher serum concentrations of chromium compared to those that received only chromium (P?<?0.05). Similarly, the hens that received chromium and vitamin C had higher serum concentrations of calcium and phosphorus compared to the hens fed with other treatments (P?<?0.05). The birds given with supplemental chromium exhibited lower serum glucose, total cholesterol, and triglycerides concentrations but higher serum albumin and total protein concentrations compared to the other groups (P?<?0.05).     

Associations between novel polymorphisms at the 5'-UTR region of the prolactin gene and egg production and quality in chickens

The objective was to characterize polymorphisms at the 5′-UTR region of the prolactin gene, and determine their association with egg production and egg quality traits in White Leghorn chickens. The study was conducted on four strains of White Leghorn chickens, namely IWH, IWI, IWK, and layer control. Overall, there were three alleles (designated A, B, and C) and five genotypes, with genotypic frequencies of 0.09, 0.75, 0.07, 0.02, and 0.07 for AA, AB, AC, BB, and BC, respectively. There were significant differences among genotypes for egg production up to 52 and 64 wk of age, with maximal egg yields for genotypes AA and AC (144.5 ± 5.06 and 143.2 ± 4.67 eggs, respectively). Furthermore, there were significant differences among genotypes for egg quality traits, including egg weight and Haugh unit at 40 wk of age, Haugh unit at 52 wk, and yolk color index and Haugh unit at 64 wk. Birds with AA or AC genotypes had the best egg quality traits. On the contrary, these genotypes had the lowest prolactin expression, whereas this expression was highest in birds with the BB genotype. In conclusion, polymorphisms at the 5′-UTR of prolactin gene were significantly associated with egg production and egg quality traits in White Leghorn chickens.     

Genetic Mapping and QTL Analysis of Growth Traits in the Large Yellow Croaker Larimichthys crocea

Large yellow croaker (Larimichthys crocea) is an important maricultured species in China. A genetic linkage map of the large yellow croaker was constructed using type II microsatellites and expressed sequence tag (EST)-derived microsatellites in two half-sib families (two females and one male). A total of 289 microsatellite markers (contained 93 EST-SSRs) were integrated into 24 linkage groups, which agreed with the haploid chromosome number. The map spanned a length of 1,430.8 cm with an average interval of 5.4 cm, covering 83.9 % of the estimated genome size (1,704.8 cm). A total of seven quantitative trait locis (QTLs) were detected for growth traits on five linkage groups, including two 1 % and five 5 % chromosome-wide significant QTLs, and explained from 2.33 to 5.31 % of the trait variation. The identified QTLs can be applied in marker-assisted selection programs to improve the growth traits.     

Effect of luteinizing hormone/choriogonadotropin receptor (LHCGR) gene on chicken reproductive traits

Luteinizing hormone/choriogonadotropin receptor (LHCGR) gene, potentially related to reproductive traits in chickens, was genotyped by using the Pooled DNA Sequencing, PCR–SSCP and Directing Sequencing techniques. 306 Erlang Mountain chickens form one line (SD03, a line that has been selected for egg quality from a local chicken breed in Sichuan province, China) were genotyped in this study. The associations between LHCGR polymorphisms and six reproductive traits [body weight at first egg (BWAFE), weight of first egg, age at first egg (AFE), number of eggs at 300 days of age (EN), body weight at 300 days of age and egg weight at 300 days of age (EWTA)] were estimated using the one-way analysis of variance method. Results showed that SNP +G4058A and SNP +T4099G of the LHCGR gene were significantly associated with BWFE and AFE. Birds with the AG genotype for the +G4058A SNP exhibited shorter AFE (P < 0.05) and greater EN than those of the GG and AA genotypes, suggesting a balancing selection (overdominance); the effect of allele C in SNP +C3021T and allele C in SNP +T4490C on EN and AFE is additive and may reflect the influence of positive selection. These alleles have promise as genetic markers for future marker-assisted selection.     

Effect of Selenium Yeast Supplementation on Naturally Acquired Parasitic Infection in Ewes

Gastrointestinal parasites cause substantial economic losses in pasture-based sheep production systems. Supranutritional organic selenium (Se) supplementation may be beneficial because it improves immune responses to pathogens. To evaluate the effect of Se-yeast supplementation on gastrointestinal parasite load, 30 ewes per treatment group were drenched weekly with no Se, 4.9 mg Se/week as Se yeast (maximum FDA-allowed concentration), or supranutritional concentrations of Se yeast (14.7 and 24.5 mg Se/week) starting early fall for 85 weeks. Fecal samples were collected at weeks 63, 66, 78, and 84 and counted for total trichostrongyle-type eggs and Haemonchus contortus eggs (in samples with ≥200 trichostrongyle eggs/g feces). During breeding season (fall), ewes were kept on pasture; ewes receiving 24.5 mg Se/week had lower fecal trichostrongyle egg counts (93?±?40 eggs/g feces) compared with ewes receiving no Se (537?±?257 eggs/g feces; P?=?0.007) or ewes receiving 4.9 mg Se/week as Se yeast (398?±?208 eggs/g feces; P?=?0.03). In winter, fecal trichostrongyle egg counts decreased, and group differences were not apparent. During lambing season (spring), ewes were kept in the barn and fecal trichostrongyle egg counts increased, although no group differences were observed. However, none of the ewes receiving supranutritional Se yeast, and with trichostrongyle egg counts ≥200 eggs/g of feces, but four of the ewes receiving lower Se dosages had H. contortus egg counts ≥1,000 eggs/g feces (P?=?0.04). Our results suggest that supranutritional Se-yeast supplementation may enhance resistance to naturally occurring H. contortus gastrointestinal parasitism in sheep.     

Effects of single and combined genotypes of MC4R and POU1F1 genes on two production traits in Langshan chicken

The objective of this study was to analyze the effects of single and combined genotypes of MC4R and POU1F1 genes in Chinese well-known indigenous chicken (Langshan chicken) population. Genetic variants within MC4R gene and POU1F1 gene were screened through PCR-SSCP and DNA sequencing methods. A C/T mutation at nt 944 in MC4R gene (NC_006089.2:g. 944C>T) and a G/A mutation at nt 3109 in POU1F1 gene (NC_006088.2:g. 3109 G>A) were identified. Associations between the mutations of the two genes with two production traits were analyzed. The results showed that, at MC4R locus, individuals with BB and AB genotypes had highly significantly higher body weight at 16 weeks (p < 0.01) than did those with the AA genotype. And, individuals within AA and AB genotypes had significantly higher egg numbers at 300 days (p < 0.05). At POU1F1 locus, individuals with CD genotype had higher body weight at 16 weeks and egg numbers at 300 days (p < 0.05). Furthermore, combined genotypes from these two loci were found to be associated with egg numbers at 300 days (p < 0.05). The individuals within combined genotype AB/CD had higher egg production. Therefore, variations identified within the MC4R and POU1F1genes are suitable for future use in identifying chickens with the genetic potential of higher body weight and reproductive traits, at least in the population of Langshan chickens.     

Effects of Dietary Supplementation of Zinc Oxide and Zinc Methionine on Layer Performance,Egg Quality,and Blood Serum Indices

The objective of this study was to evaluate the effectiveness of dietary zinc oxide (ZnO) and zinc methionine (Zn-Met) supplementation on layer performance, quality of egg, some blood constituents, and oxidative status in blood of laying hens. A total of 120 laying hens (Hisex Brown) 22-week-old were indiscriminately allotted into five groups of 24 hens with six replications (four birds/replicate). A complete randomized design experiment was performed including control (basal diet), two levels of ZnO (50 and 100 mg/kg basal diet), and two levels of Zn-Met (50 and 100 mg/kg basal diet) through 22 to 34 weeks of age. Supplementation of 100 mg of Zn-Met significantly (P = 0.001) increased feed intake compared to other treatment groups. The groups supplemented with 50 mg of ZnO and 100 mg of Zn-Met reported the significantly higher egg production rate (P = 0.002) and egg mass (P < 0.001) compared to other treated groups. All traits of egg quality were not statistically (P < 0.05 or 0.01) affected by ZnO or Zn-Met supplementation except shell thickness, Haugh unit score, and yolk to albumin ratio. Dietary supplementation of either ZnO or Zn-Met did not affect the oxidative parameters in serum except the activity of Cu-Zn-SOD. Serum triglyceride, total cholesterol, and LDL cholesterol (low-density lipoprotein) were significantly (P < 0.05) affected by Zn supplementation, while HDL cholesterol (high-density lipoprotein) did not affect. Compared to the control group, supplementation of ZnO or Zn-Met increased serum content of zinc with no differences among supplemental zinc doses. It could be concluded that dietary inorganic (ZnO) and organic (Zn-Met) supplemented up to 50 and 100 mg/kg, respectively, can be used as effective supplements to improve productivity of laying hens, serum zinc level, lipid profile (triglyceride and LDL cholesterol), and activity of Cu-Zn-SOD.     

A panel of polymorphic microsatellite markers in Himalayan monal Lophophorus impejanus developed by cross-species amplification and their applicability in other Galliformes

Isolation and development of new microsatellite markers for any species is still labour-intensive and requires substantial inputs of time, money and expertise. Therefore, cross-species microsatellite amplification can be an effective way in obtaining microsatellite loci for closely related taxa in bird species. We have reported microsatellite loci for Himalayan monal for the first time. Fifteen microsatellite markers developed for chicken were cross-amplified in Himalayan monal. All the tested 15 microsatellite markers were polymorphic, with mean (± s.e.) allelic number of 4 ± 1.51, ranging 2–7 per locus. The observed heterozygosity in the population ranged between 0.285 and 0.714, with mean (± s.e.) of 0.499 ± 0.125, indicating considerable genetic variation in this population. While 12 loci conformed to Hardy–Weinberg equilibrium (P > 0.05), 3 loci, i.e. MCW0295, MCW0081, MCW0330 deviated from it (P < 0.05). No evidence for linkage disequilibrium was observed among pair of loci. Our study show that these 15 microsatellites loci could be employed in population genetic studies for Himalayan monal and their applicability in Jungle Bush Quail, Grey francolin and Kalij pheasant.

     

A phylogenetic analysis of egg size,clutch size,spawning mode,adult body size,and latitude in reef fishes

Theoretical treatments of egg size in fishes suggest that constraints on reproductive output should create trade-offs between the size and number of eggs produced per spawn. For marine reef fishes, the observation of distinct reproductive care strategies (demersal guarding, egg scattering, and pelagic spawning) has additionally prompted speculation that these strategies reflect alternative fitness optima with selection on egg size differing by reproductive mode and perhaps latitude. Here, we aggregate data from 278 reef fish species and test whether clutch size, reproductive care, adult body size, and latitudinal bands (i.e., tropical, subtropical, and temperate) predict egg size, using a statistically unified framework that accounts for phylogenetic correlations among traits. We find no inverse relationship between species egg size and clutch size, but rather that egg size differs by reproductive mode (mean volume for demersal eggs = 1.22 mm³, scattered eggs = 0.18 mm³, pelagic eggs = 0.52 mm³) and that clutch size is strongly correlated with adult body size. Larger eggs were found in temperate species compared with tropical species in both demersal guarders and pelagic spawners, but this difference was not strong when accounting for phylogenetic correlations, suggesting that differences in species composition underlies regional differences in egg size. In summary, demersal guarders are generally small fishes with small clutch sizes that produce large eggs. Pelagic spawners and egg scatterers are variable in adult and clutch size. Although pelagic spawned eggs are variable in size, those of scatterers are consistently small.     

Early rearing enrichments influenced nest use and egg quality in free-range laying hens

In Australia, free-range egg production pullets are typically reared indoors, but adult layers get outdoor access. This new environment may be challenging to adapt to, which could impair egg production and/or egg quality. Adaptation might be enhanced through rearing enrichments. We reared 1386 Hy-Line Brown® chicks indoors with three treatments across 16 weeks: (1) a control group with standard litter housing conditions, (2) a novelty group providing novel objects that changed weekly, and (3) a structural enrichment group with custom-designed structures to partially impair visibility across the pen and allow for vertical movement. Pullets were transferred to a free-range system at 16 weeks of age with daily outdoor access provided from 25 until 64 weeks. Daily egg production at different laying locations (large nests, small nests and floor), weekly egg weights and egg abnormalities were recorded from 18 to 64 weeks old. External and internal egg quality parameters of egg weight, shell reflectivity, albumen height, haugh unit, yolk colour score, shell weight and shell thickness were measured at 44, 52, 60 and 64 weeks. There was a significant interaction between rearing treatment and nest box use on hen-day production from weeks 18 to 25 (P < 0.0001) with the novelty hens laying the most eggs and the control hens the fewest eggs in the nest box. Similarly, from 26 to 64 weeks, the novelty hens laid more eggs in the large nest boxes and fewer eggs on the floor than both the structural and control hens (P < 0.0001). Egg weight and abnormalities increased with age (P < 0.0001), but rearing treatment had no effect on either measure (both P ≥ 0.19). Rearing treatment affected shell reflectivity and yolk colour with the control hens showing paler colours across time relative to the changes observed in the eggs from enriched hens. The novelty hens may have established nest box laying patterns as they were more accustomed to exploring new environments. The differences in egg quality could be related to stress adaptability or ranging behaviour. This study shows that enriching environments during rearing can have some impacts on production parameters in free-range hens.     

Hatch and Reproduction of Globodera tabacum tabacum in Response to Tobacco,Tomato, or Black Nightshade

The effects of broadleaf tobacco, tomato, and black nightshade on juvenile hatch and reproduction of Globodera tabacum tabacum were determined in laboratory and greenhouse experiments. Root exudates from nightshade stimulated greater egg hatch than those from either ''Rutgers'' tomato or ''86-4'' tobacco. Hatch was greater at higher proportions of root exudates for all three plant species. Root exudates from plants greater than 3 weeks old stimulated more hatch than younger plants. No regression relationships existed between plant age and nematode batch. In other experiments, hatch from eggs in cysts was higher for tomato and nightshade after 10 weeks in greenhouse pots compared to tobacco and bare soil. Numbers of second-stage juveniles in eggs in cysts produced from a previous generation on the same host were highest on nightshade and less on tomato and tobacco. Cysts of variable age recovered from field soil had increased hatch in both root exudates or water compared to recently produced cysts from plants in growth chambers. Globodera t. tabacum may be subject to both host and environmentally mediated diapause.     

Impact of an energy- and nutrient-reduced diet containing 10% lignocellulose on animal performance,body composition and egg quality of dual purpose laying hens

In response to ethical concerns regarding the killing of day-old male chicks of layer breeds, the use of dual purpose chickens is increasingly discussed in public while data on nutritional requirements of dual purpose laying hens are not available. The present study examined the impact of an energy- and nutrient-reduced diet containing lignocellulose on performance, body composition and egg quality of dual purpose hens. Female Lohmann Dual chicks were allocated to 12 pens and fed two different diets for 52 weeks: a control (CON) and a treatment diet (LC), based on CON but diluted with 10% lignocellulose. During the trial, animal performance, whole-body composition and egg quality parameters of hens were consistently ascertained. The results showed that LC-fed hens had lower body weights compared to those receiving CON (p < 0.05). During the laying period, feed intake was increased in LC-fed hens (p < 0.001). LC-fed hens showed a higher egg production and egg mass resulting in an improved feed efficiency (p < 0.05) and laid smaller eggs compared to CON-fed hens (p < 0.001). At 52 weeks of age, bodies of LC-fed hens had higher protein and lower fat contents than those fed with CON diet (p ≤ 0.001). Mean body weight was positively correlated to the body fat content (p = 0.004) and body fat content was negatively correlated to the egg production (p = 0.043). Analyses of the egg quality showed that yolk mass at all sampling points and albumen mass at 27 and 42 weeks were lower in hens fed with diet LC compared to those fed with diet CON (p< 0.05). In conclusion, the feeding of energy- and nutrient-reduced diets containing 10% lignocellulose reduced the body fat content and simultaneously improved the laying performance in dual purpose hens.