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At least 1,297 records · Page 72Linked to original sources
PubMed2006

Dietary arginine silicate inositol complex during the late laying period of quail at different environmental temperatures.

Arginine silicate inositol complex (ASIdagger; arginine 49.5%, silicon 8.2%, inositol 25%) is a novel material which is a bioavailable source of silicon and arginine. ASI offers potential benefits for vascular and bone health. Poor eggshell quality has been a major economic concern to commercial egg producers. Poor egg quality, skeletal abnormalities and architectural deterioration of bone tissue are common problems under hot conditions and in older birds. The effects of ASI supplementation on egg production, egg quality, levels of osteocalcin (OC) and bone mineral content were investigated in heat-stressed Japanese quail during the later part of the laying period. The birds were randomly assigned to six treatment groups consisting of six replicates of five birds each in a 2 x 3 factorial arrangement of treatments (temperatures, ASI levels). The birds were kept in wire cages in a temperature-controlled room at either 22 degrees C (TN) or 34 degrees C (HS) for 8 h/d and fed either a basal (control) diet or the basal diet supplemented with either 500 or 1000 g of ASI/kg. Heat exposure reduced egg production, egg quality and bone mineralisation when the basal diet was fed. ASI supplementation had no effect on feed intake or egg production under TN or HS conditions. However, ASI supplementation increased egg weight, shell thickness, shell weight and Haugh unit in both TN and HS groups during the late laying period. Bone mineral density (BMD) was significantly improved by ASI supplementation in both TN and HS groups. Serum osteocalcin (OC) concentrations and alkaline phosphatase (ALP) activity increased linearly with dietary ASI supplementation during the late laying period. The amount of calcium and phosphorus in the excreta decreased, while ash, mineral content, calcium and phosphorus concentrations in tibia increased in ASI-supplemented quail in both TN and HS groups during the late laying period. ASI supplementation significantly improved egg quality and bone mineralisation in quail during the late laying period and did not affect feed consumption or egg production.

Alkaline Phosphatase↗
PubMed2004

Effect of heat stress on production parameters and immune responses of commercial laying hens.

The present study was conducted to determine the adverse effects of high temperature and humidity not only on live performance and egg quality but also on immune function in commercial laying hens. One hundred eighty 31-wk-old laying hens at peak production were used in this study. Hens were housed in cages (15 cages of 4 birds/cage) in each of 3 environmental chambers and received 1 of 3 treatments. The 3 treatments were control (average temperature and relative humidity), cyclic (daily cyclic temperature and humidity), and heat stress (constant heat and humidity) for 5 wk. Different production and immune parameters were measured. Body weight and feed consumption were significantly reduced in hens in the heat stress group. Egg production, egg weight, shell weight, shell thickness, and specific gravity were significantly inhibited among hens in the heat stress group. Likewise, total white blood cell (WBC) counts and antibody production were significantly inhibited in hens in the heat stress group. In addition, mortality was higher in the heat stress group compared to the cyclic and control groups. Even though T- and B-lymphocyte activities were not significantly affected by any of the treatments, lymphocytes from hens in the heat stress group had the least activity at 1 wk following treatment. These results indicate that heat stress not only adversely affects production performance but also inhibits immune function.

Animals↗
PubMed1995

New intermittent lighting programme (the Reading system) for laying pullets.

1. Two intermittent lighting systems for laying hens are: the Biomittent system, using an asymmetric pattern of 0.25L:0.75D for 16 h followed by 8D, which entrains oviposition to 24 h cycles and, compared with standard lighting programmes, gives the same egg number and egg size but a smaller feed cost, and a symmetrical system (4[3L:3D]) which allows intervals between ovipositions to stretch, giving bigger eggs with thicker shells, but yielding fewer eggs and achieving no saving in food intake. 2. A new system was devised to combine the increased egg size and shell thickness, characteristic of symmetrical intermittent lighting programmes, with the reduction in food intake which is a feature of programmes that reduce total activity time. The pattern tested was 24(0.25L:0.75D). 3. The results of 2 trials showed that this new system gives about 2% fewer eggs than conventional (Step Up) or Biomittent lighting with a 2% increase in mean egg size and a 3% improvement in shell thickness at the end of the laying year. Feed consumption with the new system was similar to that under Biomittent lighting and 6% lower than that recorded for Step Up lighting. 4. Mortality was lower with the new system than with Step Up lighting, but not significantly so. From the evidence of other trials it is argued that intermittent lighting programmes which provide less than 8 h total illumination in 24 h generally reduce laying house mortality and may be regarded as beneficial to the welfare of the hen.

Aging↗
PubMed2004

Effects of supplementary iodine on the performance and egg traits of laying hens.

1. This experiment was carried out to determine the effects of dietary iodine supplementation on the performance and egg traits of laying hens. A total of 600 SHSY type brown layers aged 21 weeks of age were chosen at random from a large flock. They were randomly distributed into 30 pens at 20 hens per pen. Each treatment comprised 6 replicates of 20 layers in groups of 5 birds. The diets were supplemented with 0, 3, 6, 12 and 24 mg/kg iodine as calcium iodate. The experimental period lasted 30 weeks. 2. There were no significant differences among the groups in body weight, food consumption, egg production, food consumption per kg eggs, eggshell index, eggshell breaking strength, shell thickness or egg yolk index. 3. Supplementation of the diet with 12 mg/kg iodine increased food consumption per dozen eggs compared to the groups fed on diets supplemented with 0 and 6 mg/kg iodine. 4. Egg weight was less in groups fed on diets supplemented with 12 and 24 mg/kg iodine than in the group receiving no iodine supplementation. 5. Iodine supplementation to provide 12 and 24 mg/kg reduced egg albumen index and egg Haugh units. 6. There were no significant differences among the groups in egg cholesterol and egg yolk cholesterol contents. 7. The iodine concentrations in egg yolk, egg albumen and whole egg increased with increased iodine supplementation. 8. As a result, the 3 and 6 mg/kg iodine supplementation of diet could be used to enrich the eggs with iodine without any adverse effect on performance and egg traits.

Animal Feed↗
PubMed2005

Egg geometry calculation using the measurements of length and breadth.

Egg geometrical calculations that include estimations of volume and surface areas are important for the poultry industry and in biological studies, as they can be used in research on population and ecological morphology, and to predict chick weight, egg hatchability, shell quality characteristics, and egg interior parameters. The research reported here is directed at the prediction of egg volume and surface area, and develops a formula that could be both accurate and suitable for calculations. The objective of this research was to improve the accuracy of the calculations of egg volume and surface area based on the measurements of the egg length and breadth. The experiment was carried out with 90 fresh eggs from a flock of Hy-Line Brown chicks at the age of 65 wk. The resulting formula for egg volume, V, was V = (0.6057 - 0.0018B)LB2 in which L is the egg length in millimeters, and B is the egg maximum breadth in millimeters. Egg surface area, S, was calculated as S = (3.155 - 0.0136L + 0.0115B)LB, in which both L and B are taken in millimeters.

Animals↗
PubMed1983

Inbreeding effects on traits with and without selection for part record rate of lay in chickens.

Data from inbred lines, one (D) selected for part record rate of lay and the other (C) unselected for any trait, were analyzed. After 19 generations of continuous full sib matings, the C line showed significant decreases in part record egg number, 32-week egg weight, shell thickness, full record egg number and part record rate of lay but nonsignificant decreases in hatchability, full record rate of lay, and laying house mortality. Age at first egg, Haugh unit and mature body weight showed significant increases in this line. The D line was similar to the C line in its response to the same intensity of inbreeding for all traits except full record egg number, part record rate, and fertility, each of which showed a significant decrease, and Haugh unit and full record rate of lay, which showed nonsignificant increases. Results indicated that the small advantages selection conferred on the inbred line in part record rate of lay (the selection criterion), full record egg number, and full record rate of lay were accompanied by undesirable changes in other traits, resulting in later sexual maturity, larger body weight, lower Haugh unit, fertility, and hatchability compared with the unselected line.

Animals↗
PubMed1995

Reduced dietary phosphorus levels for layers.

Two experiments were undertaken to study the response of White Leghorn hens to low dietary phosphorus levels from 18 to 64 wk of age. A corn-soybean meal diet containing .2% available phosphorus gave similar performance, up to 32 wk of age, as a similar control diet containing .4% available phosphorus. Beyond 32 wk, although shell quality and average egg weight were similar, egg production was significantly reduced with the lower phosphorus diet. Phosphorus excretion (grams per bird per day) averaged .47 g for .4% vs .28 g for .2% available phosphorus when measured at 28 wk of age. In a second experiment identical procedures and bird number as used in Experiment 1 were employed with the exception that the test diet contained .3% rather than .2% available phosphorus. No differences were noted for any of the production variables measured between the .4 and .3% available phosphorus diets. Phosphorus excretion data collected at 25, 32, 44, and 60 wk of age showed a decrease of approximately 20% for hens receiving the lower phosphorus diet. Indeed the overall average for phosphorus excretion for the lower phosphorus diet was calculated to be identical to the 20% lower total phosphorus content of this diet (.59 vs .47%).

Aging↗
PubMed2000

Survival of Yersinia enterocolitica and mesophilic aerobic bacteria on eggshell after washing with hypochlorite and organic acid solutions.

Populations of Yersinia enterocolitica 0:9 and mesophilic aerobic bacteria on the shell of fresh chicken eggs were assessed prior and after washing with 0.75%, 1%, and 3% acetic and lactic acids, 50, 100, and 200 mg/liter (ppm) of chlorine, and water. Highest reductions of mesophilic aerobic bacterial populations (normal flora) on trypticase soy agar were 1.28 and 2.15 log10 cycles with 100 and 200 mg/liter of chlorine, 0.28 and 0.36 log10 cycles with 1% and 3% acetic acid, and 0.70 and 0.71 log10 cycles with 1% and 3% lactic acid, respectively, as compared to the control group. No Salmonella or Yersinia were detected among the natural flora of the eggs. On Y. enterocolitica O:9-inoculated eggs, reductions of 2.66, 2.77, and 2.92 log10 cycles by 50, 100, and 200 mg/liter of chlorine, of 2.47, 2.48, and 2.49 log10 cycles by 0.75%, 1%, and 3% of acetic acid, and of 2.48 and 2.72 log10 cycles with 1% and 3% of lactic acid, respectively, were observed with respect to the control. Organic acids at 3% caused detachment of the surface cuticle of the eggshell. Y. enterocolitica was more sensitive to the wash treatments than the natural microflora. The absence of potentially pathogenic Y. enterocolitica, observed for other fresh foods, should be a norm for fresh eggs sold in retail stores.

Animals↗
PubMed1989

Genetic parameters of egg characteristics in Japanese quail.

Heritability, phenotypic and genetic correlations of egg characteristics of Japanese quail were investigated to obtain basal information on breeding, strain identification and genetic monitoring. For this study, 3230 eggs produced from 323 female were used. Measurement were taken on egg weight, yolk weight, albumen weight, shell weight, egg shape index, albumen height, specific gravity, shell thickness, shell strength and yolk color. Heritability estimates of egg characteristics were high and ranged from 0.62 to 0.84. Diverse phenotypic and genetic correlations were observed among egg characteristics. These results indicate that individual selection should be the most efficient method of improving egg characteristics and that consideration should be given to the interrelationship of characteristics to accomplish genetic improvement. The possibility exists these assays of egg characteristics can be used for strain identification and genetic monitoring without killing an individual of quail.

Animals↗
PubMed2002

Re-evaluation of calcium and phosphorus requirements in aged laying hens.

1. A series of 5 trials was conducted with 401- to 650-d-old Lohmann, Yafa (local breed with brown eggshells) and Yarkon (local breed with white eggshells) hens fed for 56 to 84 d with diets containing 25 to 50 g/kg calcium (Ca) and 4.5 to 7.6 g/kg phosphorus (P). 2. Increasing dietary Ca from 24-25 to 36-40 g/kg improved egg production, shell weight (SW) and shell thickness (ST), and decreased mortality. 3. Increasing dietary Ca to 48 to 50 g/kg did not affect egg production but increased SW and/or ST. In one out of the 4 trials, this effect was not significant, most likely because of the high shell quality of the eggs from the Yafa hens used for this trial. 4. Dietary P content of 4.5 g/kg (1.0 g/kg added inorganic P) appears to be sufficient for maintaining egg production and shell quality in aged laying hen given 36 to 40 g/kg Ca. 5. Increasing dietary Ca above 40 g/kg may require a higher dietary P content.

Aging↗
PubMed1991

The effect of indomethacin on eggshell quality.

The objective of the present study was to determine whether indomethacin, an inhibitor of prostaglandin synthesis, could improve shell quality in birds laying a high incidence (greater than 15%) of soft-shelled (SS) and shell-less (SL) eggs and in birds laying exclusively hard-shelled (HS) eggs. Treatments consisted of two injection types, indomethacin or oil (controls), and two injection times, 4 h or 16 h postentrance of the egg into the uterus. Indomethacin delayed oviposition in both HS and SS or SL egg layers, with indomethacin being more effective in delaying oviposition when injected at 16 h as compared with 4 h postentrance of an egg into the uterus. Indomethacin increased shell thickness of the first egg laid following injection in the SS or SL groups but not in the HS groups. Egg weight was not affected by indomethacin injection. It was concluded that indomethacin delayed oviposition and prevented the premature expulsion of some SS or SL eggs. This delay in oviposition resulted in thicker shells of the first egg laid postinjection.

Animals↗
PubMed2003

Efficacy of administration of praziquantel on 2 days 2 weeks apart against Schistosoma japonicum eggs in mice.

We compared a group of mice given multiple oral doses of praziquantel (PZQ) on 1 day 7 weeks after infection with Schistosoma japonicum and another group given multiple doses of PZQ over 2 days (7 and 9 weeks after infection) by examining the number of schistosome eggs and oograms in their tissues and feces. In the 1-day-protocol group (4 x 100 mg/kg x 1 day), calcified dead eggs or shells accounted for 77.4 and 70.1% of the total EPG (the total number of immature eggs, mature eggs, and calcified eggs and shells per 1 g tissue) in the liver and small intestine, respectively, 11 weeks after infection. Shells accounted for nearly half of the total EPG (54.3% liver and 46.6% small intestine). Mature eggs accounted for 8.4% (liver) and 5.1% (small intestine) of the total EPG. Only shells were found in the feces. In the 2-day-protocol group (4 x 100 mg/kg x 2 days, 2 weeks apart), dead eggs accounted for 87.2 and 89.5% of the total EPG in the liver and small intestine, respectively, 11 weeks after infection. Shells accounted for 62.5% (liver) and 75.8% (small intestine) of the total EPG. In the 2-day group, mature eggs accounted for 0.9% (liver) and 0.6% (small intestine) of the total EPG. In liver and small intestine, the EPG of immature and mature eggs in the 2-day group was significantly smaller than in the 1-day group. Especially, the tendency was clear in the case of the EPG of mature eggs. There were no schistosome eggs in the feces of the 2-day group. We found that administration of PZQ over 2 days separated by a 2-week interval was effective against S. japonicum.

Animals↗
PubMed1984

Effects of vitamin D3 deficiency on adenosine triphosphatase activity of jejunums from white Leghorn hens.

Supplemental vitamin D3 (D3) was removed from the diet given to an experimental group of White Leghorn hens, at 227 days of age, while a control group continued to receive a supplemental diet. By 14 days after D3 withdrawal, egg weight, egg specific gravity, shell weight, percent shell, shell thickness, and plasma calcium were lower (P less than .05) in the experimental compared to the control group. At 30 to 37 days after D3 withdrawal, experimental hens had less (P less than .05) jejunal adenosine triphosphatase (ATPase) activity than the control hens. The study indicated that lack of D3 supplementation in laying diets reduced jejunal ATPase activity as well as egg shell quality.

Adenosine Triphosphatases↗
PubMed2005

Melengestrol acetate as an effective alternative to induce a decline in egg production and reversible regression of the reproductive tract in laying hens. II. Effects on postmolt egg quality.

Induced molting increases egg quality and egg production and extends the productive life of hens. Molting is accomplished by feed withdrawal, which has received criticism, and alternatives described thus far result in poor postmolt performance. Melengestrol acetate at a dosage of 4 or 8 mg/d, in a balanced diet, leads to reversible regression of the reproductive tract. However, this alternative must also increase egg quality after rest to be considered an adequate method by the industry. Hy-Line W-36 (n = 497) laying hens were assigned randomly to a diet containing 0 mg of melengestrol acetate (MGA; control) throughout the experiment or 4 or 8 mg of MGA/d for 2, 4, or 6 wk. Upon reaching 50 and 70% lay, after MGA removal, eggs were collected for measurements of egg quality, including Haugh units (i.e., internal egg quality), shell thickness, and breaking strength (i.e., external egg quality). Haugh units were greater (P < 0.05) for eggs laid by hens molted with a diet containing 8 mg of MGA for all durations compared with controls. Shell thickness was greater (P < 0.05) when hens were treated with 4 mg of MGA for 6 wk and 8 mg of MGA for 4 and 6 wk compared with control. Egg breaking strength was greater (P < 0.05) than controls for all hens fed MGA, regardless of dosage or duration of feeding. A subset of hens was fed 8 mg of MGA per hen/d for 2 wk, and eggs were collected for 3 wk. Seven days after MGA was removed from the diet, the amount of MGA in the yolk was below the level of detection of the assay, and the concentration found in the eggs at all time points was 3 orders of magnitude below the Food and Drug Administration's tolerance for MGA in edible tissue. When used as an alterative method to induce a rest, MGA leads to an increase in the internal and external egg quality of hens compared with nonmolted hens.

Aging↗
PubMed1994

Effect of removing trace minerals from the diet of hens laying eggs with heavy or light shell weight.

Hy-Line W36 hens, 48-wk-old, were used to study the effect of removing either supplemental Fe, Cu, Zn, Mn, or all of them from the diet of hens laying eggs with heavy shell weight (HSW) or light shell weight (LSW). The experiment was conducted for 10 wk. Egg production (EP), egg mass (EM), feed consumption (FC), feed conversion efficiency (FE, grams feed:gram egg), egg weight (EW), shell weight (SW), percentage shell (PS), specific gravity (SG), percentage fertility, percentage hatchability of fertile eggs (HF), and percentage hatchability of total eggs set (HT) were measured. Removing trace minerals from the diet had no significant effect on EP, EM, FC, FE, EW, PS, SG, HF, or HT with either HSW or LSW hens. However, removing Mn from the diet significantly reduced SW with HSW hens. Diet by shell classes (HSW and LSW) interaction was not significant for any variable measured. The HSW hens had significantly higher EW, SW, PS, SG, and EM and lower EP, HF, and HT. However, there were no significant differences on FC or percentage fertility between the two groups of hens.

Animal Feed↗
PubMed2001

Correlation between shell colour and ultrastructure in pheasant eggs.

1. The histochemistry and ultrastructure of pheasant eggs were compared on the basis of blue or brown shell colour. 2. Differences in lectin histochemistry of the outer shell membrane calcification surface indicate a biochemical disruption of the calcification sites in blue eggs. 3. Significant differences were observed in all aspects of eggshell ultrastructure with blue eggs having thinner shells with structural defects. 4. Poor hatchability of blue eggs may reflect high rates of weight loss associated with a defective eggshell.

Animals↗
PubMedDate not supplied

Experimental infection of laying chickens with egg-drop syndrome 1976 virus.

Brown layer hens (BC and HC strains) and white layer hens (WL strain) orally infected with the H-162 strain of the egg-drop syndrome 1976 virus developed few clinical signs except for abnormal egg production. Depressed and/or aberrant-egg production was observed for 3 days or longer in 17 of 18 BC hens, 13 of 15 HC hens, and 10 of 17 WL hens. On the average, abnormal egg production began 8.8, 10.3, and 12.2 days after infection of the BC, HC, and WL hens, respectively. Egg production was depressed in the WL hens, but little depression was observed in the BC and HC hens. Aberrant-egg production was much less frequent in the WL hens than in the BC and HC hens. Aberrant eggs were shell-less, soft-shelled, thin-shelled, and/or discolored. No eggs of abnormal internal quality or shape were observed. The virus spread from infected BC and WL hens to contact hens.

Adenoviridae Infections↗
PubMed1987

Vitamin D metabolism and calbindin (calcium-binding protein) in aged laying hens.

Calbindin (calcium-binding protein) concentration, vitamin D metabolism and shell quality were investigated in young (7- to 9-mo-old) and aged (19- to 21-mo-old) laying hens consuming normal or low levels of calcium (Ca). Although egg weight and percent of cracked eggs were higher and egg production and shell density (mg/cm2) were lower (significantly, P less than 0.01) in aged hens, shell weight, plasma Ca and duodenal and egg shell gland calbindin were similar to those of young hens. Dietary Ca restriction reduced shell weight, shell density and structural bone and plasma Ca in both the young and aged birds. The production of 1,25-dihydroxycholecalciferol [1,25(OH)2D3] and its concentration in the plasma were higher in hens fed low dietary levels of Ca than in hens fed normal Ca levels only in the younger hens. However, a slightly higher production of 1,25(OH)2D3 and concentration of duodenal calbindin were also observed in severely Ca-restricted (1.4% Ca for 19 d) aged hens than in the younger hens. The results suggest that the aged hen loses its ability to adapt to changes in Ca intake or needs through mechanisms involving modulation of vitamin D metabolism.

25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗