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PubMed1986

Influence of cottonseed meal on vanadium toxicity and 48vanadium distribution in body tissues of laying hens.

Hens of two commercial White Leghorn strains were fed diets representing a complete factorial arrangement of 0, 3, or 6 ppm vanadium (V) from dicalcium phosphate and 0 or 5% cottonseed meal (CSM). Test diets were fed for 4 consecutive weeks beginning when hens were 25, 40, 62, or 76 weeks old. After each 4-week treatment period, all hens were fed a diet containing no added V or CSM. Albumen quality (Haugh units) was determined on eggs produced on Days 6 and 7 of each week of feeding the test diets. Three ppm V caused a slight decrease in Haugh units, while 6 ppm V reduced Haugh unit score (HU) by 6 to 15 units when fed to hens 29, 44, or 80 weeks old. The relative influence of V on HU of eggs from 66-week-old hens was less pronounced. The inclusion of 5% CSM in the diet counteracted most of the adverse effects of V on egg quality, irrespective of strain of hens. Egg production and egg weight were not affected by V or CSM. In a second experiment, hens fed diets containing no V + no CSM, 6 ppm V + no CSM, no V + 5% CSM, or 6 ppm V + 5% CSM were given 110 microCi of 48V by oral capsule. Greatest concentrations of 48V were found in bone, kidney, liver, and magnum. Little 48V was detected in whites, and none was found in yolks of eggs produced 2 days after 48V dose.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1996

[Rapeseed and rapeseed meal as components in diets of laying hens].

In an experiment with 405 Hisex white hens rations with 5-20% low glucosinolate rapeseed (RS) or rapeseed meal (RSM) of 00 quality were used. Feed intake, egg production, individual egg weight and live weight gain were reduced in hens fed 5-20% RS and 10-20% RSM. There was a positive correlation between the RS proportion in the ration and the thyroid weight as well as the iodine content of the thyroid. The relation between the iodine content related to one gram of thyroid and the RS proportion was not significant. There were not any significant differences between the RSM groups and the iodine content of the thyroid. The T3 and T4 concentrations in the blood plasma was independent of the RS- or RSM-proportion in the diet. The outward egg quality was not influenced by feeding. The Haugh units were lower when RS or RSM were offered. The fatty acid pattern of the yolk was changed by RS or RSM feeding, particularly the proportion of oleic acid increased. We concluded from the results, RS cannot be recommended for feeding white hens and only a maximum of 5% RSM should be administered.

Animal Feed↗
PubMed1988

Efficacy of infectious bronchitis virus vaccines against heterologous challenge.

Twenty-four-week-old white Leghorn layers were inoculated subcutaneously with a killed Newcastle disease-infectious bronchitis (Massachusetts type) virus (MIBV) vaccine. Twenty-eight weeks after vaccination, the birds were challenged intraocularly with the Arkansas strain of infectious bronchitis virus (AIBV) to determine the effects of heterologous virus exposure on egg production, egg quality and serum antibody response of the birds. The challenged hens laid significantly (P less than 0.005) fewer eggs than the unchallenged layers. Eggs laid by the unchallenged groups weighed significantly more (P less than 0.005) than those laid by the challenged groups. Further, the internal quality (Haugh units) and shell quality of eggs laid by the AIBV-challenged hens was significantly (P less than 0.005) inferior to those from the unchallenged hens. In addition, the AIBV-challenged hens laid more soft-shell, misshapen and small eggs than the unchallenged hens. The Arkansas serum haemagglutination inhibition (AIBV-HI) titres of AIBV challenged birds increased up to four weeks after challenge. The corresponding MIBV haemagglutination-inhibition (MIBV-HI) titres decreased during the same period. The study indicates that killed MIBV vaccine offered no protection to birds exposed to heterologous AIBV.

Animals↗
PubMed1999

Effect of dietary lipid-lowering drugs upon plasma lipids and egg yolk cholesterol levels of laying hens.

To evaluate the effect of lipid-lowering agents upon egg quality, reproductive performance, plasma lipids, and egg yolk cholesterol levels, 30-week-old Shaver laying hens were fed a basal diet (commercial ration) supplemented with 0.1% probucol (PROB), 0.025% gemfibrozil (GEMF), or lovastatin at 0.0005% (LOV1), 0.001% (LOV2), or 0.0015% (LOV3) for a 12-week experimental period. It was observed that the supplementation of the drugs did not impair albumen and shell quality. Hen performance was not adversely affected. The depression in triglyceride concentrations approached statistical significance only in LOV2 (38.5%), and total cholesterol was significantly depressed in LOV2 (36.0%), LOV3 (36.8%), PROB (29.6%), and GEMF (30.4%) treatments. Egg cholesterol content, expressed per gram of yolk, was significant lowered in LOV1 (7.5%) and LOV3 (12. 7%).

Animals↗
PubMed2002

Disrupting effects of polychlorinated biphenyls on gonadal development and reproductive functions in chickens.

Polychlorinated biphenyls (PCBs) are worldwide persistent pollutants that have produced detrimental effects on endocrine function and reproduction in a variety of species. The present study revealed effects of PCBs on gonadal development and functions in chickens of different ages. Aroclor 1254 (0-100 microg/egg) was injected into Hyline chicken eggs before incubation. The adult chickens received Aroclor 1254 by gavage (50 mg/kg BW). It was observed that in day 5 embryos, PCBs resulted in a dose-dependent decrease of primordial germ cell (PGC) numbers, and caused PGCs pyknosis and vacuolation. Clomiphen failed to block the effects of PCBs. In the newly hatched chicken, PCBs induced a marked decrease in area of the transverse sections, diameter and relative area of the testicular tubules. The differentiation of germ cells was retarded after PCB treatment. In contrast, the area of the left ovarian transverse sections, the thickness of ovarian cortex and the number of oocytes increased dramatically in the female chickens after PCB exposure. In the adult chickens, PCBs caused no significant changes in body weight, respiration, heart rate, body temperature, red and white blood cell number, but induced a marked decrease in the testicular weight, and severe damage of the seminiferous tubules. The number of the spermatogenic cells and serum testosterone level were decreased significantly by PCBs. On the contrary, in the laying hens there was no significant effect of PCB on egg quality except a slight decrease in egg weight. These results indicated that PCBs exerted its disrupting effects on chicken reproduction with a sex and stage-related pattern, and in vivo disruption of gonadal development represents a possible model for risk assessment of environmental endocrine disrupters by in ovo treatment.

Administration, Oral↗
PubMed2001

Egg marketing in national supermarkets: products, packaging, and prices--part 3.

As part of a national retail egg quality study, the variety of shell eggs and egg products offered for sale, type of packaging, and price relationships were compared in five major metropolitan regions. A total of 81 stores in 28 cities were sampled in California (CA), Illinois (IL), North Carolina (NC), Texas (TX), and New England (NE). Data were recorded for the variety of brands, sizes, white or brown shell eggs, specialty eggs, liquid or frozen eggs, carton sizes, package labeling and coding, and price relationships of shell eggs, liquid, and frozen egg products displayed for sale. The total variety of shell eggs displayed per store was the greatest for CA and NE stores. Stores in CA and TX offered more (P < 0.05) variety of white shell eggs than did stores in the other states, whereas stores in NE displayed the greatest variety (P < 0.05) of brown shell eggs. The average number of liquid and frozen egg products was highest (P < 0.05) for NC stores. Packaging type, USDA labeling, and carton coding differed somewhat among states. The price per one dozen cartons of all white shell egg sizes was highest (P < 0.05) in CA stores, and the average liquid plus frozen egg product prices were higher in CA and NE stores compared to the other states. However, the ratio of liquid and frozen product prices to all large shell egg prices was among the lowest for CA and NC stores. These data indicate that product selection, packaging, and consumer prices for shell eggs and egg products varied considerably across five separate regions of the country.

Animals↗
PubMed1986

Fluorine toxicity and laying hen performance.

Two hundred eighty-eight Single Comb White Leghorn (SCWL) hens were treated for 252 days with sodium fluoride added to a practical wheat-soybean meal-type basal diet to supply 0, 100, 400, 700, 1,000, and 1,300 ppm fluoride (F). On Day 252, hens fed the two highest levels of F were switched to the control diet and the experiment continued for another 168 days. The two highest levels of fluoride resulted in significant (P less than .05) depression of feed intake, body weight gain, hen-day production, feed efficiency, and egg quality. Fluoride (700 ppm) tended to reduce performance but generally was not significantly different from the control and lower F diets. Long-term feeding of high levels of F (NaF) did not result in permanent production impairment. Birds fully recovered during the 168-day recovery period. In the second experiment 288 SCWL pullets were treated for 49 days with seven dietary regimens: 0 ppm F fed ad libitum (1), 1,300 ppm F fed ad libitum (2), 0 ppm F control pair-fed to 1,300 ppm F (5), an NaCl diet formulated to supply as much Cl- as F- in diet 3 (4), an NaCl diet formulated to supply as much Na as supplied by NaF in Diet 3, (5), 1,300 ppm F plus 1,040 ppm Al diet fed ad libitum (6), and the same diet pair-fed to the 1,300 ppm F diet (7). All groups were fed the control diet for a 7-day recovery period at the end of the experiment. High F intake significantly (P less than .01) decreased feed intake, hen-day production, feed efficiency, and shell quality. However, these depressions were not as severe when Al was present in the diet. The depression in performance due to F feeding was not simply due to the depressed feed intake but rather was a result of a metabolic function of F. Pair feeding the control and F/Al diets resulted in much smaller depression. Egg shell quality was more responsive to the addition of Na to the diet than the F. Although feed consumption recovered within the 7-day recovery period, this time was inadequate for complete recovery in egg production.

Animals↗
PubMed2004

Quantitative trait loci with parent-of-origin effects in chicken.

We investigated potential effects of parent-of-origin specific quantitative trait loci (QTL) in chicken. Two divergent egg-layer lines differing in egg quality were reciprocally crossed to produce 305 F2 hens. Searching the genome using models with uni-parental expression, we identified four genome-wide significant QTL with parent-of-origin effects and three highly suggestive QTL affecting age at first egg, egg weight, number of eggs, body weight, feed intake, and egg white quality. None of these QTL had been detected previously using Mendelian models. Two genome-wide significant and one highly suggestive QTL show exclusive paternal expression while the others show exclusive maternal expression. Each of the parent-of-origin specific QTL explained 3-5 % of the total phenotypic variance, with the effects ranging from 0.18 to 0.4 phenotypic SD in the F2. Using simulations and further detailed analyses, it was shown that departure from fixation in the founder lines, grand-maternal effects (i.e. mitochondrial or W-linked) and Z-linked QTL were unlikely to give rise to any spurious parent-of-origin effects. The present results suggest that QTL with parent-of-origin specific expression are a plausible explanation for some reciprocal effects in poultry and deserve more attention. An intriguing hypothesis is whether these effects could be the result of genomic imprinting, which is often assumed to be unique to eutherian mammals.

Age Factors↗
PubMed1982

Influence of ingested petroleum on the reproductive performance and pituitary-gonadal axis of domestic ducks (Anas platyrhynchols).

1. The chronic ingestion of a sublethal dose (5%) of dietary North Sea crude oil delayed the onset of lay in adult Khaki Campbell ducks transferred from a short (8L:16D) to long day (16L:8D) photoperiod and greatly reduced the rate of oviposition and quality (weight and shell thickness) of the eggs subsequently laid. 2. Refeeding the oil-fed birds with the uncontaminated control diet stimulated the rate of egg production and improved egg quality, but in both cases not to the level in the controls. 3. Food intake and the plasma calcium level in the petroleum-fed birds were reduced, but these effects are unlikely to be causally responsible for the adverse effects of petroleum on avian reproduction. 4. Gonadotrophic (luteinizing hormone, LH) hormone secretion in the oil fed birds was not suppressed and the impairment of reproductive performance was not due to low plasma LH levels. 5. The reduced rate of lay in the oil-fed birds was accompanied by low gonadal steroid (progesterone) levels. The detrimental effects of oil and reproduction may be due to direct or indirect effects on the ovary or shell gland.

Animals↗
PubMed2005

The effect of feeding hemp seed meal to laying hens.

Seed of the hemp cultivar Unika-b was cold-pressed to obtain hemp seed meal (HSM) containing 307 g/kg crude protein and 164 g/kg ether extract (60 g/kg linoleic acid, 120 g/kg alpha-linolenic acid, 160 g/kg oleic acid, lesser amounts of palmitic, stearic, and gamma-linolenic acids). For 4 weeks, 102 43-week-old DeKalb Sigma hens were fed on isonitrogenous and isoenergetic diets containing 0, 50, 100 or 200 g/kg HSM. Eggs were collected for fatty acid analysis during the fourth week of feeding these diets. No significant differences were found between feed treatments for egg production, feed consumption, feed efficiency, body weight change or egg quality. Increasing dietary inclusion of HSM produced eggs with lower concentrations of palmitic acid and higher concentrations of linoleic and alpha-linolenic acids.

Animal Feed↗
PubMed2001

Maternal androgens in black-headed gull (Larus ridibundus) eggs: consequences for chick development.

We tested the hypothesis that mother birds counterbalance the negative effects of hatching asynchrony for later-hatched chicks by increasing the yolk androgen concentrations in consecutive eggs of their clutch. In doing so, they may adaptively tune each offspring's competitive ability and, thus, growth and survival. However, evidence in support of this hypothesis is contradictory. The yolk concentrations of maternal androgens in the eggs of black-headed gulls increase significantly with the laying order of the eggs in a clutch. We experimentally tested the functional consequences of this increase on chick development under natural conditions by injecting eggs with either an oil or androgen solution. We created experimental clutches in which androgen levels either stayed constant or increased with laying order while controlling for differences in egg quality by using only first-laid eggs. We then compared development, growth and survival between these broods. Androgen treatment enhanced embryonic development because androgen-treated eggs hatched half a day earlier than controls, while their size at hatching was similar to oil-treated controls. Androgen treatment did not increase chick survival, but it enhanced growth. Androgen-treated, third-hatched chicks had a higher body mass and longer legs than third-hatched chicks that hatched from oil-treated eggs. At the same time, growth of first chicks (which were all oil treated) was reduced by the presence of two androgen-treated siblings, suggesting that yolk androgens enhance the competitive ability of later-hatched chicks. Our results support the hypothesis that transfer of different amounts of androgens to the eggs of a clutch is a mechanism by which mothers maximize their reproductive output.

Androgens↗
PubMed1994

Intraspecific variation in egg size and egg composition in birds: effects on offspring fitness.

1. There is little unequivocal evidence to date in support of a positive relationship between egg size and offspring fitness in birds. Although 40 studies (of 34 species) have considered the effect of variation in egg size on chick growth and/or survival up to fledgling only 12 studies have controlled for other characters potentially correlated both with egg size and offspring fitness. Of these only two have reported a significant residual effect of egg size on chick growth (in the roseate tern and European blackbird) and three a residual effect on chick survival (all in seabirds: common tern, lesser black-backed gull and kittiwake). 2. More consistent evidence exists, though from fewer studies, for a positive relationship between egg size and offspring fitness early in the chick-rearing period; chick growth and chick survival being dependent on egg size in 8 of 10 studies and 4 of 5 studies respectively. It is suggested that the most important effect of variation in egg size might be in determining the probability of offspring survival in the first few days after hatching. 3. Egg size explains on average 66% of the variation in chick mass at hatching (n = 35 studies) but only 30% of the variation in chick body size (n = 18). When effects of hatching body size are controlled for chick mass remains significantly correlated with egg size, though the reverse is not true. This supports the hypothesis that large eggs give rise to heavier chicks at hatching, i.e., chicks with more nutrient (yolk) reserves, rather than structurally larger chicks. 4. Egg composition increased isometrically with increasing egg size in about half the studies so far reported (n equals approximately 20). However, in seabirds, and some passerines, larger eggs contain disproportionately more albumen, whilst in some waterfowl percentage yolk content increases with increasing egg size. Changes in albumen content largely reflect variation in the water content of eggs, but changes in yolk content involve variation in lipid content, and therefore in egg 'quality.' The adaptive significance of variation in egg composition is considered; females may adjust egg composition facultatively to maximise the benefits to their offspring of increased reproductive investment. 5. Considerations for future research are discussed with particular emphasis on experimental studies and the application of new techniques.

Animals↗
PubMed1988

Significance of growing photoperiod and light stimulation at various ages for Leghorn pullets subjected to regular or ahemeral photoperiods.

Leghorn pullets were cage reared to 15 or 19 wk of age in environmentally controlled rooms that provided either 8 h or 14 h of light per day. In Experiment 1, birds were moved to laying cages at 15 wk of age and subjected to either 14 h light (L): 10 h (D) dark or ahemeral 14L:14D photoperiods. Feed intake, egg weight, shell quality, and egg production were monitored to 67 wk of age. In Experiment 2, pullets were moved at 19 wk of age and subjected to 14L:10D or 17L:7D light programs. Production parameters were measured as previously described. No significant (P greater than 0.5) interactions were observed between rearing and laying photoperiods, suggesting that increase in the length of photoperiod around time of maturity is not essential for adequate performance. In Experiment 1, ahemeral lighting resulting in reduced egg production, whereas egg shell quality and egg weight were improved (P less than .05). In both experiments, the 14-h rearing program resulted in improved egg size together with improved eggshell quality (P less than .05). Whereas increased egg size may relate to body weight, no explanation is apparent for the consistent pattern with respect to shell quality. In Experiment 2, poorer shell quality was observed with 17 vs. 14 h light per day. It is concluded that light stimulation at maturity has little effect on overall egg production. Improved shell quality observed with birds reared under 14 h light vs. those reared under 8 h per day may relate to a less rapid attainment of peak egg production.

Aging↗
PubMed2004

Effects of dietary combination of chromium and biotin on egg production, serum metabolites, and egg yolk mineral and cholesterol concentrations in heat-distressed laying quails.

Chromium picolinate is used in the poultry diet because of its antistress effects in addition to the fact that the requirement for it is increased during stress. This study was conducted to determine if the negative effects of high ambient temperature (34 degrees C) on egg production, egg quality, antioxidant status, and cholesterol and mineral content of egg yolk could be alleviated by combination of chromium picolinate and biotin (0.6/2.0; Diachrome, as formulated by Nutrition 21 Inc.), in laying Japanese quails (Coturnix coturnix japanica). Quails (n= 240; 50 d old) were divided into 8 groups, 30 birds per group. The quails were fed either a basal diet or the basal diet supplemented with 2, 4, or 8 mg of Diachrome/kg diet. Birds were kept at 22 degrees C and 53% relative humidity (RH). At 14 wk of age, the thermoneutral (TN) group remained in the same temperature as at the beginning of experiment, whereas the heat stress (HS) group was kept in an environment-controlled room (34 degrees C and 41% RH) for 3 wk. Heat exposure decreased performance when the basal diet was fed (p = 0.001). Diachrome supplementation at 4 and 8 mg/kg diet, increased feed intake (p = 0.05), egg production (p = 0.05), feed efficiency (p = 0.01), egg weight (p = 0.05), and Haugh unit (p = 0.01) in quails reared under heat stress conditions. Heat exposure increased concentrations of serum malondialdehyde (MDA) (p = 0.001), glucose, and cholesterol (p = 0.01), which were elevated by supplemental Diachrome (p < or = 0.05). Egg yolk Cr, Zn, and Fe (p = 0.01) concentrations increased linearly, whereas MDA and cholesterol concentrations decreased (p = 0.05) as dietary Diachrome supplementation increased in HS groups. Similar effects of supplementation on serum levels of glucose and cholesterol (p = 0.05) and egg yolk concentrations of cholesterol (p = 0.05) and Cr (p = 0.01) were observed in TN groups. No significant differences in other values were observed in the TN groups. Results of the present study suggest that supplementation with Diachrome protects the quail by reducing the negative effects of heat stress.

Animals↗
PubMed1983

Phenotypic and genetic correlation between egg characters and embryo and chick weights of Alexandria and Fayoumi chickens.

At the Poultry Research Centre of Alexandria University phenotypic and genetic correlations were estimated on the basis of dam averages of three populations between egg quality features, embryo and chick weights. The relationships of individual egg weight, shell weight, and shell thickness as well as the egg shape on the one hand and the embryo weight at 6, 12, and 18 days of age on the other hand were weak and exhibited no uniform trend. The correlations between egg weight and chick weight were also low. The genetic correlations between shell weight and shell thickness and the chick weight up to the eighth week were even negative.

Animals↗
PubMed1993

Importance of prenatal nutrition to the development of a precocial chick.

The developmental maturity of hatchling birds varies greatly across the altricial-precocial continuum and these differences are related to the relative proportions of yolk and albumen in a species' egg. In general, the more precocial the chick the greater the proportion of yolk in its egg. Egg composition can also vary within species with unknown consequences for the developing embryo. The present research sought to determine the importance of egg composition to avian development by experimentally removing 1, 2, 4, 8, 12, or 16% of the albumen from eggs of domestic fowl (Gallus gallus). Experimental chicks were paired to control chicks whose eggs were matched on the basis of original mass and laid by the same female but no albumen was removed from their eggs prior to incubation. Decreased levels of albumen significantly decreased chick size at hatch. Experimental subjects, however, had similar growth to controls after 20 days of ad-lib access to food, although sex differences between pairs indicated that the growth of females may be affected differentially by albumen removal. Righting responses were retarded in experimental subjects for the 2 and 4% albumen-removal groups. Egg composition can have important consequences for chick survival simply by influencing body size at hatch and it is suggested that the practice of using overall egg size as a measure of egg "quality" needs to be broadened by considering what is inside the egg as well. In addition, the unique opportunity presented by using an avian model to assess directly the specific influences of protein (albumen) and of fat (yolk) on growth and behavioral development is explored.

Albumins↗
PubMed1985

The effect of oxytetracycline on the fat content and fatty acid composition of the egg yolk.

The effects of oxytetracycline (OXT) at doses of 0.291, 0.461, 0.922, 1.383 and 1.844 g/l in drinking water on the egg quality and on the fat content and fatty acid composition of egg yolk were studied. OXT had no effect on egg weight, yolk weight or shell thickness. Increasing availability of OXT in water reduced cholesterol and triglyceride in the egg yolk while it had no effect on the phospholipid content. OXT at higher doses favoured unsaturated and polyunsaturated fatty acids relative to saturated fatty acids in the yolk.

Animals↗
PubMed1989

Effects of chronic LHRH-a + 17-methyltestosterone or LHRH-a + testosterone therapy on oocyte growth in the striped mullet (Mugil cephalus).

The striped mullet (Mugil cephalus) exhibits a restricted spawning season and matures only once per spawning cycle. In vivo monitoring of ovarian maturation of individual females during the season reveals that timing of full maturity varies. A small percentage of females that mature early can be induced to spawn and will remature. Such females can be spawned a second time within the same season. Chronic administration of luteinizing hormone-releasing analog (LHRH-a) + testosterone results in accelerated egg growth. The majority of females undergoing this therapy mature at least a month before control fish. When these females are induced to spawn, a higher percentage remature and can be spawned again. The double spawnings of both control and LHRH-a + testosterone-treated females occur without any appreciable loss in egg quality. Administration of LHRH-a + 17 alpha-methyltestosterone essentially inhibits egg growth. Steroid profiles from females undergoing this therapy exhibit a significant drop in circulating testosterone and estradiol 17 beta, compared to control and LHRH-a + testosterone-treated females. Hypotheses for the poor performance of this therapy are discussed.

Animals↗