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At least 235 records · Page 13Linked to original sources
PubMed2004

Effect of dietary fumonisin B1 on laying Japanese quail.

1. A 28-d experiment was conducted to evaluate the effects of fumonisin B1 (FB1) on egg production and egg quality of young laying Japanese quail fed on fumonisin-contaminated rations. 2. To this end, 128 7-week-old birds were randomly distributed into 4 experimental groups (32 birds per group) and given rations containing 0 (control), 10, 50 and 250mg FB1/kg feed. Each treatment consisted of 4 replicates of 8 quail. Egg production and egg weight were checked daily. Feed consumption and feed conversion were determined weekly. Eggs laid on the last day of each 7-d period were collected and subjected to individual analysis for specific gravity, Haugh units and percentage eggshell. 3. Compared with controls, quail given > or = 50 mg FB1/kg had reduced feed intake and lower body weight gain. Feed conversion was reduced only in birds given 250 mg FB1/kg. 4. Mean egg production and egg weight were lower in birds given 250mg FB1/kg. Eggshell weight was reduced in birds given > or =50mg FB1/kg. However, mean specific gravity, Haugh units and percentage eggshell were not affected by FB1. 5. No histopathological changes were observed in liver, kidney or heart samples from any treatment group. 6. The results indicated that exposure to FB1 at concentrations > or = 50 mg/kg could adversely affect quail performance, emphasising the importance of controlling fumonisin contamination of quail rations.

Animal Feed↗
PubMed2003

Maternal antibodies but not carotenoids in barn swallow eggs covary with embryo sex.

Mothers influence their offspring phenotype by varying egg quality. Such maternal effects may be mediated by transmission of antibodies and antioxidants. Mothers should adjust allocation of maternal substances depending on embryonic sex because of differences in reproductive value, potentially dependent on paternal genetic effects as reflected by secondary sexual characters. We manipulated sexual attractiveness of male barn swallows (Hirundo rustica) and investigated maternal investment in eggs in relation to offspring sex. Mothers allocated more antibodies against a pathogen to eggs with a daughter than a son. However, concentration of antioxidants was independent of embryonic sex. Sex-dependent allocation was independent of paternal attractiveness. Thus, mothers adjusted allocation of substances to offspring in a complex manner, that may be part of a strategy of favouritism of daughters, which have larger mortality than sons. Such effects may have important consequences for secondary and tertiary sex ratios, but also for ontogeny of adult phenotype.

Animals↗
PubMed2003

Zinc supplementation alleviates heat stress in laying Japanese quail.

The study was conducted to determine whether zinc supplementation could alleviate the detrimental effects of high ambient temperature (34 degrees C) on egg production, digestibility of nutrients and antioxidant status in laying Japanese quail. Quail (n = 180; 52 d old) were divided into six groups (n = 30/group) and were fed a basal diet or the basal diet supplemented with 30 or 60 mg of zinc (ZnSO(4). H(2)O)/kg diet. Birds were kept at 22 degrees C and 58% relative humidity (RH). At 13 wk of age, the thermoneutral (TN) groups remained at the same temperature, whereas the heat-stress (HS) groups were kept in an environmentally controlled room at 34 degrees C and 42% RH for 3 wk. Heat exposure decreased egg production in birds fed the basal diet (P = 0.001). Linear increases in feed intake (P = 0.01) and egg production (P = 0.004) and improved feed efficiency (P = 0.01) and egg quality variables (P 0.05). Results of the present study suggest that supplementation with 60 mg zinc/kg diet protects quail by reducing the negative effects of heat stress.

Animal Nutritional Physiological Phenomena↗
PubMed1994

Effects of cage versus floor rearing environments and cage floor mesh size on bone strength, fearfulness, and production of single comb White Leghorn hens.

Fourteen hundred pullets were reared at densities of 304 and 735 cm2 in cages and floor pens with litter, respectively. Feeder spaces of 2.7, 4.0, and 5.4 cm per bird were held constant during the brooding growing period. At 18 wk of age, the birds were housed four birds per cage (348 cm2 per bird) in a force-ventilated, light-controlled house with two rows of stair-step cages. In two rows, the standard 2.5 x 5.0 cm welded wire flooring was replaced randomly with 2.5 x 2.5 cm welded wire in eight-cage sections. Egg production, egg quality, feed conversion, and mortality were measured over a 48-wk production cycle. At 68 wk of age, a sample of hens was selected and euthanatized, and the right leg was excised for further evaluation. Rearing environment, rearing feeder space, or type of layer floor mesh had no significant effects on hen-day production or feed conversion. Hens reared in cages produced heavier (P < .001) eggs with a higher percentage of Grade A eggs and had fewer body checks than floor-reared birds. Femur, tibia, and shank lengths were not affected by the rearing treatments or the type of flooring in the layer cage. Tibia breaking strength was not different for the rearing systems or hens maintained on 2.5 x 2.5 vs 2.5 x 5.0 cm welded wire mesh flooring. Hens reared in floor pens on litter displayed a higher level of fearfulness at the end of the production cycle. The reduced (P < .05) body weights associated with cage rearing and reduced feeder space did not negatively affect the production variables. Alteration of the mesh size of layer cage floor had no effect on the production levels of the hens.

Animal Husbandry↗
PubMed1995

Non-invasive electrogastrography. Part 2. Human electrogastrogram.

The electrical activity of human stomach muscle wall-electrogastrogram (EGG), was led off by surface (cutaneous) electrodes placed on the abdominal wall and recorded on an electrogastrograph. A method for complete elimination of the cardiac artefact was elaborated and successfully implemented. It consists of a preliminary elimination of the QRS complex, based on its higher amplitude and slope. The eliminated intervals were replaced by linear segments. A subsequent low-pass filtering allowed to obtain a high quality EGG signal. The electrical activity of the stomach of healthy volunteers was characterized by waves with a frequency of 3.35 +/- 0.09 cpm during the quiescent periods and 2.99 +/- 0.14 cpm during the activity periods of the migrating myoelectrical complex (MMC). Bearing in mind the correlation between the bursts of spike potentials with the slow waves in the dog EGMG and the high-amplitude waves, characterizing the periods of activity in the dog EGG, we can better differentiate the periods of quiescence and activity by the amplitude of the waves. The wave amplitude during periods of quiescence was 81.13 +/- 20.61 microV, significantly different from the wave amplitude during periods of activity being 164.74 +/- 43.34 microV (n = 7). Thus with this method in visual inspection it is possible to identify MMC of the human stomach by the changes in the amplitude of the waves in the EGG.

Action Potentials↗
PubMed2007

Expression of positional candidates for shell thickness in the chicken.

Expression of 12 positional candidates for QTL affecting shell thickness at 53 wk of lay age (ST53) was investigated by real-time PCR in the distal part of chicken oviducts (uterus) with a forming eggshell. In the local chicken breed Green-legged Partridgenous, the complete cDNA CR523443 (ChEST985k21) was downregulated with ratio of means 0.49 (P < or = 0.01) in the group with low ST53 (248.6 +/- 16.62 microm) relative to the group with the highest ST53 (372.4 +/- 2.07 microm). Expression of this gene was highly correlated (0.85, P < or = 0.01) with shell thickness. No significant difference in expression between the 2 groups with thick (378.4 +/- 3.65 microm) and thin (227.8 +/- 8.99 microm) shell and no significant correlation of expression level with ST53 were detected in Rhode Island Red, which could be explained by strict selection to egg quality traits, including optimal shell thickness in this commercial layer breed. These data suggested that CR523443 was a candidate gene for QTL ST53 in the chicken.

Animals↗
PubMed1990

Bioavailability of fluorine in sepiolite for laying hens.

The purpose of the present work was to compare the bioavailability of structural fluorine contained in sepiolite and in sodium fluoride for laying hens. Three hundred 27-wk-old laying hens were fed one of three diets: 1) a control based on corn, barley, and soybean meal containing 21 mg/kg of fluorine; 2) a sepiolite diet in which 2% sepiolite replaced 2% barley in the control diet and which contained 217 mg/kg of fluorine; and 3) a NaF diet, consisting of the same control diet to which NaF was added to contain 217 mg/kg of fluorine (the same level of F- as the sepiolite diet). The experiment ended when hens were 64 wk old. Fluorine concentration in the tibial bone of hens fed the NaF diet was four times higher than in the control, and twice as high in eggshell. In contrast, hens fed sepiolite had fluorine concentrations in tibial bone and eggshell not significantly higher than fluorine concentrations in the controls. These results indicate that fluorine from sepiolite was not available. The effects of the different diets on egg production, feed intake, feed conversion, egg weight, shell and interior egg quality, dry matter of feces, and body weight gain were also determined but no significant differences due to the dietary treatment were observed.

Animals↗
PubMed1986

Effects of type of cage partition, cage shape, and bird density on productivity and well-being of layers.

In Experiment 1 there were no significant differences in rate of lay, egg quality, latency to feeding, and feather condition of hens in cages with wire mesh or solid metal side partitions. Birds in cages with solid metal side partitions had significantly higher mortality (6%) and weight gain (6%) than those in cages with wire side partitions. The deep caged hens had significantly lower mortality (8%) than the shallow caged hens. Hens housed at 464 cm2 of floor area/hen had significantly higher hen-housed egg production (4.9%), lower weight gain (8%), and higher average feather scores (.8 unit) than those housed at 348 cm2. In Experiment 2 type of cage side and back partitions (wire vs. solid metal) significantly affected grams of egg per gram of feed. Birds in deep cages had significantly lower mortality (8.6%) and higher feed consumption (15.2 g/hen/day) than those in shallow cages. Hen-housed rate of lay, mortality, weight gain, feed conversion, and feather scores were significantly affected by bird density: 64.6%, 15%, 24.6%, .384% g egg/g feed, and 4.7 units, respectively, for hens with 464 cm2 floor area vs. 70.8%, 8.3%, 25.2%, .362% g egg/g feed, and 5.8 units for hens with 348 cm2. Data suggest that hens in cages with solid metal sides performed similarly to their sisters in cages with wire mesh sides and backs.

Animals↗
PubMed2001

The effect of shell egg pasteurization on the protein quality of albumen.

The effect of a low-temperature, extended-time, in-shell pasteurization process on the protein quality of egg albumen was evaluated. Ten dozen fresh chicken eggs were pasteurized in a hot-air oven at 55 C for 180 min. The eggs were refrigerated and broken out for analysis on Days 0, 7, 14, 28, 42, and 56 following pasteurization. There were no significant differences in total or soluble protein over the experimental period for the pasteurized or unpasteurized albumen. Mean protein content was 80.6 +/- 0.5% for the pasteurized albumen and 80.9 +/- 0.5% for the unpasteurized albumen. In vitro digestibility, as measured by the AOAC method, was 82.4 +/- 0.7% for the pasteurized albumen and 81.7 +/- 0.6% for the unpasteurized albumen. There were no significant differences over the experimental period in the digestibility of the samples. Free amino acids and discriminant-computed protein efficiency ratio (DC-PER) also did not differ between the pasteurized and unpasteurized albumens or over the experimental period. The in-shell pasteurization process used had no effect on the protein quality of albumen.

Amino Acids↗
PubMed2005

Effects of carotenoid availability during laying on reproduction in the blue tit.

Carotenoids are antioxidant pigments involved in several physiological processes and signalling in animals that cannot synthesise them and therefore must acquire them from food. We experimentally investigated the effects of carotenoid availability in the diet during egg laying on antioxidant deposition in egg yolk and the related effects on nestling condition, female body condition and parental investment in the blue tit (Parus caeruleus). Carotenoid supplementation of egg-laying females resulted in a significant increase in carotenoid concentration in egg yolk, but not in vitamin E or A concentration. There was no relationship between yellow plumage colour of adult females and carotenoid deposition in eggs, and no differential effect of feeding treatment depending on female colour. Nestlings from eggs laid by carotenoid supplemented females had longer tarsi, had faster development of the immune system as reflected by leukocyte concentration in blood, and grew brighter yellow feathers than nestlings from control females. However, nestlings from the two groups did not differ significantly in body mass, plasma antioxidants or plumage colour hue. At the time of chick rearing, carotenoid-fed females had increased plasma vitamin E levels compared to controls. However, females from the two treatment groups did not differ significantly in body condition or feeding rate. These results suggest that carotenoid availability is limiting during egg laying, and that females may have to balance the benefits of investing in egg quality against the potential costs of impairing their own future antioxidant protection. In addition, there may be considerable variation in carotenoid availability not only across seasons, but also among different stages of the breeding season.

Animals↗
PubMed1999

Comparison of physical quality and composition of eggs from historic strains of single comb White Leghorn chickens.

The effect of long-term genetic selection on physical quality and composition of eggs was determined by analyzing eggs acquired from Agriculture Canada: Ottawa Control Strain 5 (CS5) from a 1950 base population, 7 (CS7) from a 1958 population and 10 (CS10) from a 1972 population. Eggs from the H&N "Nick Chick" current commercial strain (CCS) were also included. Eggs were collected monthly over a 62-wk laying period and analyzed for egg, albumen, shell and yolk weight; albumen protein, solids and pH; percentage yolk solids and fat; Haugh units; and specific gravity. Significant (P < 0.05) differences found between strains included a progressive increase in weight of eggs from the CS5 to CCS. Although the eggs increased in size, no significant differences were found between strains for specific gravity or percentage shell weight. Yolk weights of eggs from the strains examined did not differ. However, the percentage of yolk found in current strain eggs was significantly lower (P < 0.05), with a subsequent higher percentage albumen due to the increase in egg size of the CCS. Haugh units were significantly higher in the CS10 and CCS strains than in the other strains. No significant differences between strains were seen in albumen protein, solids, pH, or yolk solids. Mean percentage yolk fat assay values for eggs from the CS5, CS7, CS10, and CCS strains were 33.08, 32.68, 32.84, and 32.40, respectively. Percentage yolk fat values obtained from CCS were significantly lower (P < 0.05) than those obtained from the other strains. The results from this study indicate that genetic selection has produced larger eggs containing a lower percentage of yolk while overall egg quality has been maintained or improved.

Aging↗
PubMedDate not supplied

F strain Mycoplasma gallisepticum vaccination of post-production-peak commercial Leghorns and its effect on egg and eggshell quality.

Forty-five-week-old commercial leghorns negative for antibodies to Mycoplasma gallisepticum (MG) and M. synoviae were vaccinated with high-passage F strain MG (FMG). Hens were confined in modified Horsfall-Bauer isolation units through 60 weeks of age. Egg production (% hen day) and parameters of egg and eggshell quality were monitored, including egg weight, eggshell strength, Haugh unit score, pimpling, and blood/meat spot incidence. Egg production was significantly lower (P less than 0.05) for FMG vaccinates than controls (down 5.76% and 5.80% in Trials 1 and 2, respectively). However, vaccinates and controls did not differ significantly in eggshell strength, shell thickness, pimpling, or blood/meat spot incidence. Haugh unit scores were significantly (P less than 0.05) greater for FMG vaccinates. At necropsy, all reproductive tracts appeared grossly normal. These studies suggest that high-passage FMG vaccination of post-production-peak hens does not adversely affect oviduct function.

Animals↗
PubMed2002

Effects on health and blood plasma parameters of laying hens by pure nivalenol in the diet.

The effects of trichothecene nivalenol (NIV) on the health and production of laying hens were determined in a feeding study. White Leghorn hens, 55 weeks old, were fed diets containing 0, 1, 3 and 5 mg NIV/kg during 50 days. Feed intake was reduced by NIV, but there were no effects on body weight, egg production and egg quality. Traces of unaltered NIV were found in liver and bile. Alkaline phosphatase in the blood plasma increased in the hens fed 0, 1 and 3 mg NIV/kg diet but decreased in the birds fed 5 mg NIV/kg feed. Total protein and glucose were slightly reduced in hens fed 5 mg NIV/kg diet. Pathological examination revealed that 40-75% of hens fed NIV (3 and 5 mg/kg) supplemented diet showed gizzard lesions, haemorrhages in the duodenum and swollen cloaca and oviducts with immature eggs while certain birds in the 1 mg NIV group showed light and fragile livers. NIV and the metabolite de-epoxy-NIV in faeces were found to constitute up to 10% of ingested NIV.

Alkaline Phosphatase↗
PubMed2003

Effect of enzyme addition to wheat-, barley- and rye-based diets on nutrient digestibility and performance of laying hens.

1. Laying hen performance, egg quality, intestinal viscosity and nutrient apparent digestibility were evaluated with respect to the main cereal used in the diet and dosage rate of a fungal beta-glucanase/xylanase enzyme complex. 2. Twelve diets were arranged factorially, with three soluble fibre cereals (SFC); 500 g/kg of wheat or barley or 350 g/kg of rye, and 4 enzyme concentrations (0, 250, 1250 and 2500 mg/kg). An additional control diet based on maize was also included. 3. The use of SFC in the diet instead of maize did not affect egg production or food efficiency, but hens fed on SFC diets exhibited a higher incidence of dirty eggs than hens fed on the maize diet (8-6 vs 4.6%; P<0.01). 4. Laying hens fed on enzyme-supplemented diets produced more eggs (2.1%; P<0.05) and had better food efficiency per dozen eggs (2.5%; P<005) than hens fed on non-supplemented diets. An excess of enzymes in the diet (10 times the recommended dose) did not produce any deleterious effect on laying hen productivity. 5. Enzyme supplementation (ES) reduced intestinal viscosity (P<0.001) and the incidence of dirty eggs (P<0.01). The reduction in viscosity was more pronounced in barley than in wheat or rye diets (P<0.05). 6. Apparent nutrient digestibility in SFC diets was higher with ES, including dry matter (3.1%; P=0.08), fat (4.4%; P<0.001), non-starch polysaccharides (83.3%; P<0.01) and AMEn (2.5%, P<0.01). 7. It is concluded that substitution of maize by SFC is facilitated by ES, especially with respect to egg production, food conversion efficiency and egg shell cleanliness. An excess of enzymes did not produce any deleterious effect on nutrient digestibility or performance of laying hens.

Animal Feed↗
PubMed1986

Ahemeral light-dark cycles and intermittent photoperiod effects on laying hens.

To compare the effects of using continuous (C) vs. intermittent (I) photoperiods with normal (24 hr) and a long but decreasing light-dark cycle (LDLDC) on production performance and egg quality, 240 White Leghorn hens of the University of Missouri-Columbia strain were individually caged in light-controlled rooms. Treatments applied at 21 weeks of age were light-dark cycles (LDC) of 25 hr gradually reduced to 23.5 hr with C or I photoperiods, and 24-hr LDC (controls); C or I photoperiods were gradually increased from 13.75 to 16 hr for the 25- to 23.5-hr LDC, and from 13.75 to 15 hr for the 24-hr LDC. Data were obtained on hen-day egg production, egg weight, egg mass, egg specific gravity, Haugh units, feed consumption, and feed efficiency. Hen-day egg production was significantly greater (P less than .01) for the combined C photoperiod treatments, while hens consumed significantly less (P less than .05) feed exposed to the combined I photoperiod treatments. Egg specific gravity was significantly better (P less than .05) for the LDLDC vs. the 24-hr LDC program with the difference being attributed to an increase (P less than .05) in initial egg specific gravity with the use of a 24-hr LDC. Egg weight, egg mass, Haugh units, and feed efficiency were not affected (P greater than .05) by LDC or photoperiod treatments.

Animals↗
PubMed2005

Stress hormones: a link between maternal condition and sex-biased reproductive investment.

In species where offspring fitness is sex-specifically influenced by maternal reproductive condition, sex allocation theory predicts that poor-quality mothers should invest in the evolutionarily less expensive sex. Despite an accumulation of evidence that mothers can sex-specifically modulate investment in offspring in relation to maternal quality, few mechanisms have been proposed as to how this is achieved. We explored a hormonal mechanism for sex-biased maternal investment by measuring and experimentally manipulating baseline levels of the stress hormone corticosterone in laying wild female European starlings (Sturnus vulgaris) and examining effects on sex ratio and sex-specific offspring phenotype adjustment. Here we show that baseline plasma corticosterone is negatively correlated with energetic body condition in laying starlings, and subsequent experimental elevation of maternal baseline plasma corticosterone increased yolk corticosterone without altering maternal condition or egg quality per se. Hormonal elevation resulted in the following: female-biased hatching sex ratios (caused by elevated male embryonic mortality), lighter male offspring at hatching (which subsequently grew more slowly during postnatal development), and lower cell-mediated immune (phytohemagglutinin) responses in males compared with control-born males; female offspring were unaffected by the manipulation in both years of the study. Elevated maternal corticosterone therefore resulted in a sex-biased adjustment of offspring quality favorable to female offspring via both a sex ratio bias and a modulation of male phenotype at hatching. In birds, deposition of yolk corticosterone may benefit mothers by acting as a bet-hedging strategy in stochastic environments where the correlation between environmental cues at laying (and therefore potentially maternal condition) and conditions during chick-rearing might be low and unpredictable. Together with recent studies in other vertebrate taxa, these results suggest that maternal stress hormones provide a mechanistic link between maternal quality and sex-biased maternal investment in offspring.

Animals↗
PubMed2004

Descriptive study of California egg layer premises and analysis of risk factors for Salmonella enterica serotype enteritidis as characterized by manure drag swabs.

This cross-sectional, double-blind study reports the prevalence of Salmonella enterica serotype enteritidis (SE) on California egg layer premises using single vs. pooled manure drag swabs and presents a description of egg production and management systems in the state and an initial analysis of risk factors for SE. The study included 91% of all known eligible egg premises in California, representing the majority of eggs produced in the state. The overall prevalence of SE on California egg layer premises was 10.5%, while 1.1% of all rows sampled were positive for SE. The percentage of positive rows for SE on any premises never exceeded 25% of the 16 swabs collected per premises. A description of egg production and management on California egg layer premises is presented. Statistically significant associations for SE were not evident and were limited because of sample size and the low prevalence of SE on California egg layer premises. Several biological and management factors, such as flock health, stage of production, manure management, ventilation, and watering systems, show trend associations with premises positive for SE and require further investigation. Manure drag swabs serve as a useful tool to validate the core components of an egg quality assurance program for SE based on process control principles.

Animal Husbandry↗
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↗