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A ten-generation experiment with growing and laying quails were carried out to test diets with 40 (starter) or 50% (grower, layer) isogenic or transgenic (Bt 176) corn. Feeding of diets containing genetically-modified corn did not significantly influence health and performance of quails nor did it affect DNA-transfer and quality of meat and eggs of quails compared with the isogenic counterpart.
The distribution of conceptions after artificial insemination from a donor was studied in 259 conceptions at an artificial insemination clinic and found to be seasonal. Conception was not influenced by the number of donors or patients attending the clinic, the frequency of inseminations, or medical skill. Conception was more common from early winter until early spring (October to March) with a peak in November. As variables such as frequency of intercourse and ovulation were irrelevant in these women and highest sperm counts occur from February to March these results suggested a seasonal variation in the quality of the ovulated egg or endometrial receptivity. The waste of eggs after ovulation (or preimplantation conceptuses) at specific times of the year has implications in the treatment of infertility, particularly for in vitro fertilisation and gamete intrafallopian transfer.
Nephropathogenic infectious bronchitis (NIB) was diagnosed in 28 infectious bronchitis virus (IBV)-vaccinated commercial chicken flocks in Pennsylvania from December 1997 to July 2000. Early dinical signs were increased flock mortality and urinary water loss (polyuria and pollakiuria) leading to wet litter. Daily mortality ranged from 0.01% in layers to 2.45% in broilers, with total broiler mortality as high as 23%. Severe renal swelling and accumulation of urates in the tubules were commonly seen. Visceral gout and urolithiasis were less frequently observed. Histopathologic changes included characteristic tubular epithelial degeneration and sloughing with lymphoplasmacytic interstitial nephritis. Minimal respiratory disease signs were noted in broilers. Egg production and shell quality declined in layers. Confirmatory diagnosis of NIB was made by IBV antigen-specific immunohistochemical staining of the renal tubular epithelium and virus isolation. Sequencing of the S1 subunit gene of 21 IBV isolates showed the NIB outbreak to be associated with two unique genotypes, PA/Wolgemuth/98 and PA/171/99. The cases from which the genotypes were isolated were clinically indistinguishable. The NIB viruses were unrelated to previously recognized endemic strains in Pennsylvania and were also dissimilar to each other. Genotype PA/Wolgemuth/98 was isolated almost exclusively during the first 14 mo of the outbreak, whereas PA/171/99 was recovered during the final 18 mo. The reason for the apparent replacement of PA/Wolgemuth/98 by PA/171/99 is not known.
Many countries use wastewater for irrigation. The World Health Organization established, as reuse guidelines, a maximum value of 1 helminth ovum/L for irrigation. Various techniques for enumerating helminth ova in water have been published. To determine the most adequate method for Mexico, four techniques were compared: the U.S. Environmental Protection Agency (U.S. EPA), membrane-filter, Leeds I, and Faust. Two types of water were used: drinking water and municipal wastewater effluent. Sensitivity, discrimination coefficients, precision, recovery efficiency, and cost were determined. In addition, several unseeded wastewater samples were analyzed. For drinking water, U.S. EPA and the membrane-filter techniques demonstrated comparable results; however, when wastewater was used, the membrane technique showed some deficiencies. Because the U.S. EPA technique may be used for samples with both high and low solids content, allows for the recovery of helminth ova with different specific gravities, and has the lowest total cost, it was selected as the best technique.
Two experiments were conducted to determine if previously suggested nutrient requirements of broiler breeders (23 g protein, 850 mg sulfur amino acids, 4.5 g calcium, and 750 mg phosphorus/bird/day) are in excess and could be reduced during the laying period. In Experiment 1, Cobb color-sex broiler breeders were fed daily nutrient allowances that were 100.0, 96.3, 92.5, 89.4, and 86.6% of the suggested requirements. In Experiment 2, Cobb feather-sex breeders were fed daily allowances that were 92.5, 89.4, 86.6, 83.4, and 80.9% of the suggested requirements. Birds on all diets were fed the same energy level; however, energy varied with season to maintain body weight. Egg production, fertility, hatchability, egg weight, and shell quality were not significantly affected by the reductions in nutrient intake in either experiment. The diet with the lowest nutrient level (80.9% of the suggested requirement) was adequate, indicating a considerable margin of safety for the stated requirements. Body weight was quite variable but tended to decrease with nutrient restriction. Weights of broilers hatched from treated breeders were not significantly affected at 49 days of age by the breeder dietary treatments. These results indicate that broiler breeder diets formulated to meet presently suggested requirements have a large margin of safety and a reduction of specifications by approximately 10% is suggested. The revised daily intakes recommended are: 20.6 g protein, 754 mg sulfur amino acids, 400 mg methionine, 938 mg lysine, 1379 mg arginine, 256 mg tryptophan, 4.07 g calcium, 683 mg total phosphorus, and 170 mg sodium.
Three experiments were conducted by sampling a total of 15,705 eggs from Leghorn hens fed diets varying in methionine, Na, and Ca content. In Experiment 1, birds of four different ages were housed in a common environment and fed diets containing between .233 and .383% methionine. In Experiment 2, birds of five different ages were housed in a common environment and fed diets containing .15, .30, and .45% Na and .25, .45, and .65% nonphytate phosphorus (NPP). In Experiment 3, eggs were sampled from 42 to 62 wk of age in 4-wk intervals from hens fed diets containing from 3 to 9% Ca in increments of 1.5%. Feeding lower levels of methionine (.233%) produced significantly lower egg weights and greater shell strength but at the expense of a decline in egg production at early ages. Reducing the NPP level from .65 to .25% produced lower egg weights and greater shell strength. A corresponding drop in production was not observed except at the .45%-Na level. No significant effects of Na on shell strength were observed. Higher Ca levels produced greater shell strength and had variable effects on egg weight. Increasing the Ca level beyond 6% resulted in a significant decline in production. Regression analyses indicated that within a population, the relationship between egg weight and shell strength is positive. In some instances, the relationship was curvilinear, where the positive association between egg weight and shell strength decreased with increasing egg weights.
An experiment was conducted to test the hypothesis that the decline in eggshell quality over time during egg production, and its improvement after molting, paralleled the rate of calcium uptake by the duodenum of the laying hen. In vitro duodenal calcium uptake rate and femur ash (percentage of femur weight) were determined at 37, 45, 51, 58, 68, and 72 wk of age. Percentage shell and shell thickness (millimeters) were determined at 22, 29, 36, 44, 50, 57, and 71 wk of age. Molt was induced at 63 wk of age. Three commercial strains DeKalb XL-Link, ISA/Babcock B-300V, and Hy-Line W-36 were compared. There were no differences in duodenal calcium uptake rate among strains. There was a significant decline (P < .01) in duodenal calcium uptake from 408 pmol/mg tissue per min at 37 wk of age to 329 pmol/mg per min at 58 wk of age. Femur ash decreased (P < .01) from 50.8% at 37 wk of age to 47.6% at 58 wk of age. Percentage shell and shell thickness declined (P < .01) from 9.79% and .403 mm at 22 wk of age to 8.88% and .373 mm at 57 wk of age, respectively. After the induced molt, duodenal calcium uptake increased (P < .01) to 402 pmol/mg tissue per min, and percentage shell and shell thickness increased (P < .01) to 10.23% and .389 mm, respectively. Duodenal calcium uptake increased immediately postmolt, whereas femur ash did not increase until 72 wk of age (P < .01).
The characteristics and regulation of oocyte maturation in the normal menstrual cycle is reviewed and the mechanisms by which ovarian hyperstimulation with exogenous gonadotrophins, used in assisted reproductive techniques, can disturb this process, is discussed. It is postulated that derangements induced in the maturation of oocytes in the hyperstimulated cycle result in the recovery of poor quality oocytes at egg-pickup which have a reduced potential to undergo normal fertilisation and subsequent embryonic development.
Although varicocelectomy is generally believed to improve semen quality and the hamster egg penetration assay, these parameters do not correlate well with in vitro fertilization (IVF) success. The effect of varicocelectomy on IVF of human oocytes was examined on thirteen couples with normal female fertility, but severe oligozoospermia and the presence varicocele in the males with failure of fertilization preoperatively in in vitro fertilization-embryo of transfer (IVF-ET) attempts. The couples were readmitted for the IVF-ET procedure following varicocelectomy. A 31% pregnancy rate was achieved after the operation, while no pregnancies occurred before surgery. Sperm density and motility improved significantly after operation, resulting in a coinciding improved fertilization and pregnancy rates.
OBJECTIVE: To assess the quality of parenting and psychological adjustment of egg donation families as the child approaches adolescence in comparison with donor insemination (DI) and IVF families. DESIGN: A study of 17 egg donation families, 35 DI families, and 34 IVF families with a 12-year-old child. Standardized interview and questionnaire measures were administered to mothers and children. SETTING: Follow-up of families recruited from three assisted conception units in the United Kingdom. PATIENT(S): Mothers and their 12-year-old children conceived through egg donation, DI, and IVF. INTERVENTION(S): Mothers and children were interviewed and administered questionnaires. MAIN OUTCOME MEASURE(S): Parents' marital and psychological state, quality of parent-child relationships, father's contribution to parenting, and children's socioemotional development. RESULT(S): No differences were found between the egg donation and IVF families. The differences between egg donation and DI families reflected lower levels of sensitive responding of egg donation mothers toward their children compared with DI mothers. Donor insemination mothers were more likely to be emotionally over-involved with their child than egg donation mothers. The egg donation children were well adjusted in terms of their social and emotional development. CONCLUSION(S): The findings are discussed in relation to the different pattern of genetic relationships between egg donation and DI families and the secrecy surrounding the use of donated gametes to conceive a child.
The effect of the oil-spill dispersant Corexit 9527 on egg-hatching rate of Macrobrachium rosenbergii (de Man) was studied by using an innovated flow-through bioassay technique. This bioassay method relies on the fact that M. rosenbergii fertilized eggs when detached from the mother prawn were able to hatch artificially. The flow-through system generated a stable and good water quality environment for hatching the eggs successfully. The Corexit 9527 had a pronounced effect on hatching rate of the M. rosenbergii eggs. In the control, the hatching rate of the eggs was 95.55% +/- 1.74%. However, it was reduced drastically with increasing concentrations of Corexit 9527. A 100% inhibition of egg hatchability was found when the level of Corexit 9527 was higher than 250 mg litre(-1). The EC(50) and the EC(95) values estimated by the probit method were 80.4 +/- 5.5 mg litre(-1) and 193.5 +/- 39.9 mg litre(-1) respectively (P = 0.05). The recommended safety level of Corexit 9527 for M. rosenbergii in Malaysian estuarine waters is below 40 mg litre(-1).
Quality and fertility of sperm extended in egg yolk-Tes-Tris were compared with those of sperm in egg yolk-citrate and homogenized milk extenders. Extended semen was frozen in .5-ml plastic straws at 11, 15, 17, or 22 X 10(6) sperm per insemination dose. Laboratory evaluations at 0, 1, 2, and 4 h after thawing semen utilized four tests of spermatozoal quality. Use of egg-yolk citrate extender resulted in a higher percentage of progressively motile sperm as determined visually at 0 h after thawing than use of egg yolk-Tes-Tris or homogenized milk extenders. Sperm extended in egg yolk-citrate had 18% lower activity of bound amidase at 0 h than sperm extended in egg yolk-Tes-Tris. The 75-d nonreturn rates were affected by insemination dose but not be extender or the interaction of extender and insemination dose. Fertility was lower after insemination of 11 X 10(6) sperm than for pooled data for the three higher insemination doses (64 vs. 68%). Based on all data, postthaw quality of sperm processed in the one-step egg yolk-Tes-Tris extender was similar to that for sperm extended in egg yolk-citrate or homogenized milk.
Since 1995, the publicly funded ready-to-eat food sampling and examination activities in Wales have been coordinated and structured, using a novel approach for the identification of samples and premises. The latest set of data from this surveillance system reports the results from 3391 ready-to-eat foods sampled between November 2003 and March 2005. During this seventeen-month period all samples were examined for aerobic colony count, Escherichia coli, Listeria spp., Bacillus cereus, Salmonella, Staphylococcus aureus and Listeria monocytogenes. The food types with the poorest microbiological quality were cream cakes, custard slices and egg mayonnaise sandwiches. The food type with the best microbiological quality was dried fruit. In conclusion, the results indicate that, in general terms, the ready-to-eat food types sampled and examined in this period posed little bacterial hazard to consumers.
When the availability of sperm limits female reproductive success, competition for sperm, may be an important broker of sexual selection. This is because sperm limitation can increase the variance in female reproductive success, resulting in strong selection on females to compete for limited fertilization opportunities. Sperm limitation is probably common in broadcast-spawning marine invertebrates, making these excellent candidates for investigating scramble competition between broods of eggs and its consequences for female reproductive success. Here, we report our findings from a series of experiments that investigate egg competition in the sessile, broadcast-spawning polychaete Galeolaria caespitosa. We initially tested whether the order in which eggs encounter sperm affects their fertilization success at two ecologically relevant current regimes. We used a split-clutch-split--ejaculate technique to compare the fertilization success of eggs from individual females that had either first access (competition-free treatment) or second access (egg competition treatment) to a batch of sperm. We found that fertilization success depended on the order in which eggs accessed sperm; eggs that were assigned to the competition-free treatment exhibited significantly higher fertilization rates than those assigned to the egg competition treatment at both current speeds. In subsequent experiments we found that prior exposure of sperm to eggs significantly reduced both the quantity and quality of sperm available to fertilize a second clutch of eggs, resulting in reductions in fertilization success at high and low sperm concentrations. These findings suggest that female traits that increase the likelihood of sperm-egg interactions (e.g. egg size) will respond to selection imposed by egg competition.
A series of Ca(2+) oscillations during mammalian fertilization is necessary and sufficient to stimulate meiotic resumption and pronuclear formation. It is not known how effectively development continues in the absence of the initial Ca(2+) signal. We have triggered parthenogenetic egg activation with cycloheximide that causes no Ca(2+) increase, with ethanol that causes a single large Ca(2+) increase, or with Sr(2+) that causes Ca(2+) oscillations. Eggs were co-treated with cytochalasin D to make them diploid and they formed pronuclei and two-cell embryos at high rates with each activation treatment. However, far fewer of the embryos that were activated by cycloheximide reached the blastocyst stagecompared tothose activated by Sr(2+) orethanol. Any cycloheximide-activated embryos that reached the blastocyst stage had a smaller inner cell mass number and a greater rate of apoptosis than Sr(2+)-activated embryos. The poor development of cycloheximide-activated embryos was due to the lack of Ca(2+) increase because they developed to blastocyst stages at high rates when co-treated with Sr(2+) or ethanol. Embryos activated by either Sr(2+) or cycloheximide showed similar signs of initial embryonic genome activation (EGA) when measured using a reporter gene. However, microarray analysis of gene expression at the eight-cell stage showed that activation by Sr(2+) leads to a distinct pattern of gene expression from that seen with embryos activated by cycloheximide. These data suggest that activation of mouse eggs in the absence of a Ca(2+) signal does not affect initial parthenogenetic events, but can influence later gene expression and development.
As natural eggs can contribute significantly to overcoming dietary deficits, we have designed and studied the composition of multiple-enriched eggs (Benefic eggs) whose composition is close to the natural egg. They are obtained by feeding laying hens in the usual way, but using additional autoclaved linseed, minerals, vitamins and lutein to provide the extra components. These eggs have greater nutritional value than standard. Thus 100 g of these eggs contains 6 times more of the omega-3 fatty acid ALA (15% of the French recommended daily allowance (RDA)), 3 times more DHA (100% of RDA), 3 times more vitamin D (30% of RDA), 4 times more folic acid (70% of RDA), 6 times more vitamin E (66% of RDA), 6 times more lutein and zeaxanthine (70% of international recommendation), 2.5 times more iodine (100% RDA), and 4 times more selenium (45% RDA). As the content of omega-6 fatty acids remains unchanged, the omega-6/omega-3 ratio is lower, and thus improved. These eggs contain a little less cholesterol and, like standard eggs, are rich in vitamin B12 (160% of RDA) and vitamin A (25% of RDA), plus vitamin B2 (riboflavin), vitamin B5 (pantothenic acid) and phosphorus. Proteins quality is indeed excellent. These eggs are interesting for everybody, and particularly appropriate for older people. The nutritional value of enriched eggs (similar to the multiple-enriched eggs of this study) has been assessed in animals and in human volunteers in terms of their influence on blood lipids. They improve the blood concentration of omega-3 fatty acids, HDL cholesterol, LDL cholesterol and triglycerides.
PCBs, organochlorine pesticides and dioxins/furans in snapping turtle eggs and plasma (Chelydra serpentina) were evaluated at three Areas of Concern (AOCs) on Lake Erie and its connecting channels (St. Clair River, Detroit River, and Wheatley Harbour), as well as two inland reference sites (Algonquin Provincial Park and Tiny Marsh) in 2001-2002. Eggs from the Detroit River and Wheatley Harbour AOCs had the highest levels of p,p'-DDE (24.4 and 57.9 ng/g) and sum PCBs (928.6 and 491.0 ng/g) wet weight, respectively. Contaminant levels in eggs from St. Clair River AOC were generally higher than those from Algonquin Park, but similar to those from Tiny Marsh. Dioxins appeared highest from the Detroit River. The PCB congener pattern in eggs suggested that turtles from the Detroit River and Wheatley Harbour AOCs were exposed to Aroclor 1260. TEQs of sum PCBs in eggs from all AOCs and p,p'-DDE levels in eggs from the Wheatley Harbour and the Detroit River AOCs exceeded the Canadian Environmental Quality Guidelines. Furthermore, sum PCBs in eggs from Detroit River and Wheatley Harbour exceeded partial restriction guidelines for consumption. Although estimated PCB body burdens in muscle tissue of females were well below consumption guidelines, estimated residues in liver and adipose were above guidelines for most sites.
Genetic correlations are often predictive of correlated responses of one trait to selection on another trait. There are examples, however, in which genetic correlations are not predictive of correlated responses. We examine how well a cross-environment genetic correlation predicts correlated responses to selection and the evolution of phenotypic plasticity in the seed beetle Stator limbatus. This beetle exhibits adaptive plasticity in egg size by laying large eggs on a resistant host and small eggs on a high-quality host. From a half-sib analysis, the cross-environment genetic correlation estimate was large and positive (rA=0.99). However, an artificial-selection experiment on egg size found that the realized genetic correlations were positive but asymmetrical; that is, they depended on both the host on which selection was imposed and the direction of selection. The half-sib estimate poorly predicted the evolution of egg size plasticity; plasticity evolved when selection was imposed on one host but did not evolve when selection was imposed on the other host. We use a simple two-locus additive genetic model to explore the conditions that can generate the observed realized genetic correlation and the observed pattern of plasticity evolution. Our model and experimental results indicate that the ability of genetic correlations to predict correlated responses to selection depends on the underlying genetic architecture producing the genetic correlation.