Influence of Fusarium-infected corn and F-2 on laying hens

Diets containing either Fusarium-infected corn supplying 25 and 100 p.p.m. of F-2 (zearalenone) or purified F-2 at these levels did not adversely influence the reproductive performance of laying hens. In trial 1, no deleterious effects were observed for 20- and 36-week body weights, age at first egg, egg weight, albumen height, shell deformation, fertility or hatchability when Fusarium-infected corn was fed to 20-week-old pullets for 28 days. Percent hen-day egg production of birds fed Fusarium-infected corn supplying 25 and 100 p.p.m. of F-2 was superior (P less than or equal to 0.5) to egg production of nontreated controls. In trial 2, three replications of ten adult Leghorn hens were evaluated under five dietary treatments: (1) 16.7% protein basal; (2) basal plus Fusarium-infected corn (25 p.p.m. of F-2); (3) basal plus 25 p.p.m. of (purified) F-2; (4) basal plus Fusarium-infected corn (100 p.p.m. of F-2); (5) basal plus 100 p.p.m. of (purified) F-2. Difference between dietary treatments for 14-day pre-treatment, treatment and post-treatment periods were nonsignificant for 42- and 44-week body weights, egg production, egg weights, fertility and hatchability. Body weights of chicks from hens fed F-2 diets were not significantly different from those of chicks from hens fed the basal diet.     

Effects of dietary taurine on egg weight

Two experiments were conducted to determine whether taurine supplementation to laying hens would influence laying performance. In Experiment 1, a total of 120 White Leghorn hens were fed diets supplemented with 0, 0.25, or 0.5% taurine for 5 wk. Egg weight was reduced significantly by supplementing 0.25 and 0.5% taurine; however, taurine did not affect other laying performance variables. In Experiment 2, a total of 240 White Leghorn hens were fed diets supplemented with 0 or 0.5% taurine and 0 or 0.1% methionine for 7 wk. Egg weight was decreased due to supplementing taurine in the diets; however, dietary methionine did not affect egg weight, and there was no interaction between dietary taurine and methionine. These results suggest that dietary taurine has the potential to decrease egg weight without affecting egg production, feed conversion, or body weight.     

Effects of different cereal grains in diets for laying hens on production parameters and liver fat content

Two experiments were conducted with White Leghorn laying hens to study the effects of different cereal grains on production criteria and liver fat content. The results of Experiment 1, in which pullets 21 weeks of age were used for a period of 22 weeks indicated that Gaines wheat or triticale (Trailblazer) were equal to corn in supporting egg production, egg weight and body weight, with comparable feed consumption. Henry wheat(a hard red winter class) was slightly, yet significantly (P less than 0.05) inferior to corn for the above criteria. No significant differences were observed among four treatments in wet liver weight and liver fat content. Hens fed the corn diet had significantly (P less than 0.05) lower carcass fat followed by the hens fed triticale in comparison with those fed Gaines or Henyry wheat. Mortality was very low and not related to dietary treatments. Neither dietary fat nor energy content was related to fat content of liver and carcass of the hens. Body weight and liver fat content were not closely related to each other. Wet liver weight was the only significantly (P less than 0.05) related factor to liver fat content. In the second experiment, in which hens 33 weeks of age were used for an experimental period of 20 weeks, opaque-2 corn was slightly superior to normal corn and triticale was comparable to normal corn in supporting egg production and egg weight. Supplementation of the diets containing the two corns and triticale with lysine failed to improve egg production and egg weight. Hens fed the diets containing either normal corn or opaque-2 corn as the only grain in the diet had significantly (P less than 0.05) higher liver fat content in comparison with hens fed the diet containing triticale as the only grain. Mortality, however, was much higher among hens fed triticale-containing diets in comparison with groups fed corn-containing diets in spite of the fact that they had significantly lower liver fat content. Regardless of dietary treatments or grains used, the hens that died were diagnosed to have fatty liver hemorrhagic syndrome. Dietary fat content was postively and significantly (P less than 0.05) related to liver fat content. Dietary energy or body weight was not closely related to liver content. Liver fat content and mortality were negatively related to each other. The higher for content did not adversely affect laying performance.     

The effect of light regimen, floor space, and energy and protein levels during the growing period on body weight and early egg size

Experiments were conducted to determine the possibility of reducing the daily requirement of laying hens for Ca, available P (AP), and protein by providing the hens with adequate levels of these nutrients only during those hours of the day that the physiological need for these nutrients for formation of various components of the eggs are increasing. The results of the Ca experiment indicated that the daily Ca requirement cannot be reduced by providing the hens with adequate levels of Ca during the afternoon (1500 to 2100 h) and inadequate Ca level during the morning (0500 to 1500 h). Providing the hens with most of the daily Ca need during the afternoon did not have a beneficial effect on shell quality as compared to the control group that received a diet with 3.5% Ca during the morning and the afternoon. On the other hand, inadequate Ca intake during the afternoon adversely affected shell quality as compared to the control group (P < 0.05). The AP experiment indicated that egg production performance and shell quality can be maintained satisfactorily as long as the daily intake of AP is adequate, regardless of whether most of the AP is consumed during the morning or the afternoon. Egg production and shell quality of hens fed a diet with 0.4% AP during the morning and 0.1% AP during the afternoon or 0.1% AP during the morning and 0.4% AP during the afternoon were not different than the control group that received a diet with 0.25% AP during the morning and the afternoon. The results of two protein experiments failed to indicate that egg production performance of laying hens can be maintained satisfactorily by providing them with an adequate level of protein (16%) only during the morning and inadequate level of protein (10%) during the afternoon or, conversely, compared to the control group that received a diet with 16% protein both during the morning and afternoon (P < 0.05). The supply of adequate protein with sufficient amino acids, during the morning and the afternoon, was required for satisfactory maintaining egg production performance. Under the conditions selected for the conduct of this study, the results of the current experiments, combined with those of a previous report, failed to support the hypothesis that satisfactory performance may be maintained by providing the hens with adequate levels of protein, AP, and Ca only during those hours of the day when the physiological need for these nutrients for formation of various components of the egg are increasing.     

Effect of feeding clinoptilolite (zeolite) on the performance of three strains of laying hens

1. One hundred and twenty 16-week-old single combed pullets of three strains were fed on a diet containing 135 g protein/kg with or without 50 g clinoptilolite/kg in a trial with 20 hens per treatment. Sterile river sand replaced clinoptilotile in the control diet in order to keep the diets isoenergetic. The hens were individually caged in a naturally ventilated laying house and fed one of the two diets for ten 28-d periods. 2. Significant dietary effects of feeding clinoptilolite were observed with number of eggs laid per hen, shell thickness, efficiency of food utilisation and droppings moisture content. No significant dietary effects between treatments were observed with body weight, age at first egg, egg weight. Haugh units, food intake/hen and rate of amino acid absorption of radioactive lysine and methionine into the bloodstream. Significant differences between strains were observed with regard to all parameters except food intake/hen. There were no significant strain X clinoptilolite interactions.     

Effect of hen production age on egg composition and embryo development in commercial Pekin ducks

At 26, 31, 36, and 42 wk of age, eggs were collected from the same duck breeder flock to study the effects of hen production age on egg composition and embryo development. At each hen age, yolk and albumen measurements were made on a random subsample of unincubated eggs. Embryo and yolk sac measurements were made at 20, 22, 24, 26, 27, and 28 d of incubation. Egg weight was significantly affected by hen production age, but most of the observed age effects occurred between 26 and 31 wk with minimal age differences thereafter due to a quantitative feed restriction for egg weight. Yolk weight increased significantly with hen production age, with the largest increase, 6.6 g, also occurring between 26 and 31 wk of age. Yolk-free duckling weight increased with hen production age at 27 d of incubation. The yolk sacs of embryos from the 31-, 36-, and 42-wk-old hens were heavier at 20 and 22 d, before the differentiation in embryo weight. Differences in yolk sac weight were not consistently affected by hen production age between 26 and 28 d of incubation. The eggs from the 42-wk-old hens weighed 3.3 g less than those from the 31-wk-old hens, but yolk-free duckling weight at 27 d was 2.9 g heavier from the 42-wk-old hens.     

Effect of feeding raw and treated common vetch seed (Vicia sativa) on the performance and egg quality parameters of laying hens

Two experiments were conducted to study the effect of feeding raw or treated common vetch seeds (V) on BW, feed intake (FI), egg production (EP), feed conversion (FC), egg weight (EW), shell thickness (ST), yolk color score (YC), and Haugh unit score (HU) of Single Comb White Leghorn hens for 56 d. In Experiment 1, diets contained 0, 7.5, 15, and 22.5% raw V. Compared with the control, the 22.5% V diet decreased (P < .05) BW, FI, and EP. In Experiment 2, intact or ground (G) V were either soaked (S) in water (1:5) for 24 h or autoclaved (A) at 103.5 x 10(3) Pa for 8 h, and then dried (D) at 55 C for 24 h. Eight diets were used, a corn soybean (control) and seven others, each containing 25% V, previously subjected to the forementioned treatments as follows: untreated V (UV), SDV, GSDV, ADV, GADV, SADV, and GSADV. Compared with the control, the UV diet decreased (P < .05) FI (75 vs 98 g) and EP (47.3 vs 88.7%), increased FC (1.99 vs 1.4 kg feed per dozen eggs), and induced BW loss (-63 vs 49 g). Soaking intact V improved (P < .05) FI (85 g) and EP (69%). Remaining treatments resulted in further improvement. Hens fed all V diets produced eggs with HU score 13 points better than that of the control (P < .05). In both experiments, EW, YC, and ST were not different among treatments. Results indicated that autoclaved V at 25% level was not detrimental to layers' performance.     

Effect of calcium propionate on performance of laying hens

Laying hens kept in individual cages were fed a practical diet supplemented with 0, 0.1, 0.2., 0.4, or 0.8% calcium propionate for a six-week period. Rate of egg production, average egg weight, feed consumption, and body weight change during the experiment were not significantly affected by and dietary treatments. Liver weight, moisture content and fat content were also no significantly affected by dietary treatments. The results show that the performance of normal hens is not changed by calcium propionate supplementation.     

Fucoxanthin metabolites in egg yolks of laying hens

Feeding experiments were conducted with White leghorn laying hens fed a carotenoid depleted control diet (containing some zeaxanthin and lutein) or this diet supplemented with 15% seaweed meal of established carotenoid composition. Egg yolk colour was estimated by use of a Roche Yolk Colour Fan and by detailed quantitative and qualitative carotenoid analysis of individual eggs of three laying hens during 4 weeks. Identification of the carotenoids included HPLC. VIS, MS, 1H NMR data and partial synthesis. The results confirmed that fucoxanthin, the major carotenoid in seaweed meal, is not transferred to the yolk. However, fucoxanthin gave rise to the metabolites fucoxanthinol, fucoxanthinol 3'-sulphate and paracentrone, that are ascribed to enzymatic modifications occurring in the hens. The difuranoid auroxanthin encountered in the egg yolk was ascribed to violaxanthin and/or its furanoid derivatives present in the seaweed meal. Colour of individual yolks varied considerably. The pigmentation level is discussed.     

Influence of dietary osteolathyrogens on the eggshell quality of laying hens

1. Laying hens were fed osteolathyrogens, either semicarbazide hydrochloride at 0.3 or 0.4 g/kg or beta-aminopropionitrile fumarate at 0.5 or 0.6 g/kg diet to examine their effects on eggshell quality. 2. Shell quality characteristics considered for evaluation were shell surface area, shell thickness, shell weight, percentage shell, shape index and the specific gravity of eggs. Measurement of shell quality traits revealed that the hens fed osteolathyrogens laid eggs with significantly lower specific gravities and proportion of shell by weight. These differences were not explained by differences in shell thickness or weight or the shape index of eggs. 3. It was concluded that osteolathyrogens cause hens to lay eggs with poor shell quality and such eggs are weak and fragile.     

The effects of F strain Mycoplasma gallisepticum, Mycoplasma synoviae, and the dual infection in commercial layer hens over a 44-week laying cycle when challenged before beginning of lay. I. Egg production and selected egg quality parameters

In each of two trials, 160 commercial pullets were separated into four treatments with four replicates of 10 chickens in each treatment. Forty pullets were designated as controls and received no inoculation; 40 other pullets received F strain Mycoplasma gallisepticum (FMG); an additional 40 pullets received Mycoplasma synoviae (MS); and the final 40 pullets were inoculated with both FMG and MS (dual). Hen-day egg production, egg weight, eggshell strength, Haugh unit score, pimpling incidence, and blood/meat spot incidence were monitored and recorded in each trial through an entire laying cycle. No significant difference was observed among the treatments for hen-day egg production, egg weight, eggshell strength, or Haugh unit scores. Significant differences were observed for pimpling incidence among controls (1.63%), Mycoplasma gallisepticum (MG)-infected (2.09%), and dual-infected hens (2.41%). A significant difference in blood/meat spot incidence was observed between MG-infected hens (0.27%) and dual-infected hens (0.45%). Histopathologic examination of the ovary and all segments of the oviduct revealed no significant differences among the treatments. These results suggest that the majority of the hen reproductive tract functions similarly in FMG-vaccinated, MS-infected, or dual-infected hens as compared with Mycoplasma-clean hens.     

Threonine requirements of laying hens

In order to determine the Thr requirement of laying hens, two experiments were conducted using laying performance and plasma Thr concentration as parameters. At 29 and 39 wk of age, 100 and 600 laying hens in Experiments 1 and 2, respectively, with average BW and high egg production rate, were randomized, housed in individual cages, and given free access to water and experimental diets with five graded levels of Thr: 0.31, 0.39, 0.46, 0.54, and 0.61% for 21 d in Experiment 1 and diets with 0.31, 0.36, 0.41, 0.46 and 0.51% Thr for 58 d in Experiment 2. On the last day of the experiment, blood samples were taken for determination of plasma amino acid concentration. Feed intake and daily egg mass increased and then decreased linearly as dietary Thr increased. Plasma Thr increased slowly, then sharply with increasing dietary Thr levels. Using the broken-line model, the Thr requirements were estimated to be 0.425, 0.428, and 0.430% or 453, 456, and 458 mg/hen per d in Experiment 1 and 0.395, 0.404, and 0.400%, or 457, 467, and 462 mg/hen per d, in Experiment 2, for egg mass, feed efficiency, and plasma Thr concentration, respectively. These results indicate that the Thr requirements expressed as milligrams per hen per day as determined by plasma Thr concentration agree with those of laying performance.     

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.     

Effects of dietary fat and eggshell cuticle removal on egg water loss and embryo growth in broiler hatching eggs

The effects of dietary fat and eggshell cuticle removal on egg water loss, embryo growth, and hatchability were determined in eggs from broiler breeder hens at different ages. Hens were fed isocaloric diets containing one of three different types and levels of added fat. In addition, eggs were either left intact or washed to remove the eggshell cuticle prior to set. Cuticle removal increased egg water loss between 43 and 62 wk. Cuticle removal increased relative wet embryo weight at Week 52 and relative dry embryo weight at 52 and 62 wk. Furthermore, at 62 wk, diet and day of incubation interacted to affect wet embryo weight, and diet variably affected dry embryo weight. No treatment differences were observed for cumulative hatchability, rate of hatch, and relative yolk sac weight at Day 19 of incubation. It was concluded that cuticle removal and the addition of fat to breeder diets may influence embryonic growth without having any subsequent effects on hatchability.     

Organoleptic evaluation of eggs produced by laying hens fed diets containing graded levels of flaxseed and vitamin E

Eighteen-week-old laying hens were fed diets containing 0, 10, or 20% ground flaxseed and 10 or 100 IU vitamin E/kg diet, in a factorial arrangement. When birds were 60 wk of age, eggs were collected from various treatments and used in taste panel studies. All studies involved freshly boiled eggs. In Experiment 1, four separate panels were conducted to obtain information on egg aroma, egg flavor, presence of any off-flavor, and overall acceptability of the egg. Pooled data showed a very significant difference among panelists for all attributes tested (P < 0.01) and off-flavors were detected in eggs from hens fed 10 and 20% flaxseed with 10 mg vitamin E/kg. In Experiment 2 panelists were asked to evaluate egg aroma, yolk flavor, and overall acceptability in eggs from birds fed the lowest level of vitamin E with 0 or 10% flaxseed, and birds fed 20% flaxseed and 10 or 100 mg vitamin E/kg. The highest ratings for egg aroma, yolk flavor, and overall acceptability were for the control eggs. There was a significant reduction in overall acceptability as flaxseed concentration increased (P < 0.05) and an interesting and significant (P < 0.05) decline in overall acceptability for birds fed 100 vs 10 IU vitamin E/kg diet in eggs for birds fed 20% flaxseed. In a third study, there was an indication of preference for eggs from birds not fed flaxseed, when the diet contained 10, rather than 100 IU vitamin E/kg diet. These data suggest that high (> 10%) levels of flaxseed used in the bird's diet will result in some decrease in overall egg acceptability as assessed by aroma and flavor. These effects seem to be accentuated by using high levels of vitamin E in the bird's diet.     

Liver lipid accumulation and performance of hens as affected by cage density and initial body weight

Hens housed in individual cages (25 46 cm.) laid significantly more eggs, consumed significantly more feed and had significantly larger livers with a higher lipid content than hens housed three to a cage in two experiments. Body weight gain was significantly higher for individually housed birds in experiment 1, but not in experiment 2. No difference was observed in mean egg weight or kg. feed per dozen eggs. In experiment 2 hens housed two to a cage laid slightly fewer eggs and accumulated slightly less liver fat but the differences were not significantly different fromthose housed individually. Hens socially dominant in three bird pens had higher liver fat accumulation than hens lower on the peck order but liver fat accumulation for the dominant hens still averaged less than hens housed either two or one per cage. Comparison of two strains in experiment 1 revealed a significant difference in rate of egg production and feed efficiency but no difference in liver fat accumulation. Pullets placed in four body weight classes prior to the start of the experiment did not differ significantly in liver fat accumulation per unit of body weight or percentof dry matter of the liver at the end of the experiment. Rate of egg production and feed efficiency were also not significantly different among the body weight classes.     

Concentrations of salinomycin in eggs and tissues of laying chickens fed medicated feed for 14 days followed by withdrawal for 3 days

Laying chickens were fed medicated feed containing various concentrations of sodium salinomycin (SAL) for 14 days followed by a 3 day withdrawal period. Eggs, collected during treatment and withdrawal, tissues and ovarian yolk of birds slaughtered after 0, 1, and 3 days' withdrawal were extracted and analysed by high performance liquid chromatography (HPLC). Tissues, ovarian yolk and freeze-dried egg albumen and yolk were extracted with acetone, followed by partitioning with petroleum ether and HPLC analysis. Albumen was extracted with methanol and analysed without further clean-up. Salinomycin was detected at 520 nm after post-column reaction with vanillin at 95 degrees C. Recoveries of fortified salinomycin from freeze-dried eggs (albumen and yolk) and tissue, premix and feed were nearly quantitative (> 90%), except liver which was < 85%. The detection limit was estimated to be 5 ng g-1, with the practical quantifiable limit being about 10 ng g-1. Highest SAL concentrations were in the more fatty components such as egg yolk, ovarian yolk and subcutaneous fat. SAL residues in other tissues were generally low and followed the order liver, kidney, thigh and breast muscles. SAL residues were dependent on the SAL concentration in feed and declined rapidly during withdrawal.     

Amino acid supplementation of turkey breeder rations

Beltsville Small White turkey hens (60) were randomized into four groups of 15 hens each, weighed and placed in individual laying cages. Immediately after lighting to initiate production, they were placed on a practical type turkey breeder diet calculated to contain 18.26% protein, 2893 Cal. M.E./kg., 3.13% Ca, 0.80% available P, 1.04% arginine, 0.86% lysine, 0.50% methionine & cystine and 0.24% tryptophane. Amino acids were added to this diet as follows: (1) none; (2) 0.1% lysine; (3) 0.05% methionine and (4) 0.1% lysine & 0.05% methionine. Lysine (0.1%) had no effect on reproductive performance when added to the basal ration or to the ration containing additional methionine. Methionine addition (0.05%) improved production significantly (P less than or equal to .005), improved feed efficiency, and increased egg size.     

Effect of dieldrin and calcium on the performance of adult Japanese quail (Coturnix coturnix japonica)

Two experiments were conducted to determine the effects of dieldrin and calcium on reproductive performance of quail. At 25% egg production the quail received diets containing 0,10 or 25 p.p.m. of dieldrin for 6, 28-day periods in experiment 1 and 0, 5, or 25 p.p.m. of dieldrin for 4, 28-day periods in experiment 2. Pesticide treatments were employed with diets containing 0.5% and 3.0% calcium. The results show that egg shell thickness, cracked eggs, egg production, feed consumption, egg weights, fertility, hatchability and body weights were not affected by dieldrin treatments. However, egg shell thickness, cracked eggs, egg production and hatchability were adversely affected by the lower calcium level. Female body weights were consistently heavier for the low calcium diet. Mortality increased in the presence of 10 and especially 25 p.p.m. of dieldrin. Livability of chicks from hens receiving rations with 10 and 25 p.p.m. of dieldrin was significantly lower than those fed no dieldrin. In summary, dieldrin was without effect on egg shell quality or other reproductive factors but did exert a detrimental effect on adult mortality and livability of progeny.     

Serum and egg yolk IgG antibody titers from laying chickens vaccinated with Pasteurella multocida

Through determining the serum and egg yolk antibody titers in immunized laying hens to Pasteurella multocida regularly, the growth-decline trend of the egg yolk antibody levels was found to be similar to that of the serum antibody levels (r = 0.94), but the growth and decline of the egg yolk antibody seemed to be delayed 3-6 days compared with that of the serum antibody, and the egg yolk antibody titers were generally lower than those of the serum antibody (P < 0.01). Serum and egg yolk antibody levels declined 3 and 6 days, respectively, after booster immunizations. The higher the antibody levels were before booster immunization, the more they declined.