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PubMed2005

Effects of S6-strain Mycoplasma gallisepticum inoculation at ten, twenty-two, or forty-five weeks of age on the performance characteristics of commercial egg laying hens.

Experimental inoculation of commercial laying hens, maintained under controlled conditions, with the S6-strain of Mycoplasma gallisepticum (S6MG) at 10 wk of age has previously been shown to affect the lengths and weights of various portions of the reproductive tract without affecting subsequent performance. Two trials were conducted to compare the effects of S6MG inoculation at 10 wk of age (prior to lay), 22 wk of age (onset of lay), and 45 wk of age (during lay) on performance characteristics in commercial layers housed and maintained under controlled conditions, as in previous studies. In each trial, BW, mortality, egg production, egg weight, eggshell weight per unit of surface area, percentage eggshell weight, percentage albumen weight, percentage yolk weight, and yolk weight per albumen weight ratio were examined at various ages throughout an entire laying cycle. Across wk 47 and 58 (age periods after the last 45 wk inoculation), eggshell weight per unit of surface area and percentage eggshell weight were significantly reduced in birds that had received an S6MG inoculation at 45 wk of age when compared with birds that had not received an S6MG inoculation or had been inoculated with S6MG at either 10 or 22 wk of age. Alterations in eggshell quality in response to S6MG may become evident only in older birds that are experiencing declines in production when housed under controlled conditions.

Aging↗
PubMed1977

Effects of T-2 toxin on reproductive performance and health of laying hens.

Purified T-2 toxin was fed to S.C.W.L. hens at levels of 0 (control), 0.5, 1.0, 2.0, 4.0 and 8.0 p.p.m. of an otherwise balanced diet. Feed consumption, egg production and shell thickness were significantly (P less than 0.05) decreased in hens fed 8 p.p.m. as compared with control hens. The fertility and progeny performance were not depressed by feeding T-2 toxin, but the hatchability of fertile eggs of hens fed 2 and 8 p.p.m. was significantly (P less than 0.05) lower than that of hens fed the control diet. The weights of liver, heart, gizzard and spleen were not influenced by T-2 toxin. Serum levels of alkaline phosphatase, LDH and uric acid of hens fed high concentrations of T-2 toxin were greater than those of control hens. SGPT in hens fed 8.0 p.p.m. was lower when compared with control hens. No outward changes in hematocrit, hemoglobin, erythrocyte, leukocyte and differential leukocyte counts were noted with feeding T-2 toxin. Most hens fed T-2 toxin developed oral lesions: circumscribed proliferative yellow caseous plaques at the margin of the beak, mucosa of the hard palate and angle of the mouth, and tongue. The incidence and severity of lesions were proportional to the dietary level of T-2 toxin. The only other lesion observed in necropsy examination at the end of the experiment was the small mucosal ulcer in the anterior portion of the gizzard in hens fed high levels of T-2 toxin. Microscostrointestinal tract, etc.) revealed no significant pathological change except the necrotic lesions in the gizzard and crop.

Alanine Transaminase↗
PubMed1993

Research note: effect of carbonated drinking water on production performance and bone characteristics of laying hens exposed to high environmental temperatures.

An experiment was conducted to determine the effects of providing heat-stressed laying hens with carbonated drinking water on production performance and tibia bone breaking strength. A total of 32 commercial laying hens (89 wk of age) were housed in an environmental chamber and exposed to 1 wk of a constant thermoneutral temperature (21 C), followed by 6 wk of a daily heat stress temperature cycle (34 C for 8 h; 21 C for 16 h). One half of the hens received tap water and the other half were provided carbonated water immediately after housing. Following 6 wk of heat stress temperature exposure, all hens were killed by cervical dislocation and left tibia bone strength measurements were taken. Hen-day egg production, egg weight, egg yield, feed consumption, and feed efficiency did not differ between water treatments; however, egg specific gravity was depressed for hens provided carbonated versus tap drinking water. Left tibia bone breaking strength per 100 g body weight was improved (P < or = .05) for hens provided with carbonated drinking water during exposure to heat stress temperatures. These results suggest that carbonated drinking water may enhance bone integrity by increasing tibia bone breaking strength of older laying hens exposed to a short-term heat stress period.

Animals↗
PubMed1995

Turkey breeder hen performance by strain during consecutive lay periods.

The results of this study provide information about reproductive performance among commercially available strains of Large White Turkey breeder hens, Nicholas (N), British United (B), and Hybrid (H). The hens were managed identically through two consecutive lay periods, summer-fall (1st-yr) followed by winter-spring (recycled). Effects of the intensity (351 vs 24 lx) of supplemental light were evaluated during the 1st-yr lay period. Data were collected for onset of oviposition, egg production, BW, feed consumption, livability, egg weight, and egg components. Light intensity had similar effects on all variables measured. There were neither strain differences nor genetic interactions with light intensity treatment. There was no difference in livability among strains (P = .20) or between year of lay (P = .08), and there was no strain by year interaction. Body weight differed by strains and year and there was a significant strain by year interaction. In general, N were heavier than H or B in the 1st-yr and early recycle lay period, whereas H and B were similar in BW in both lay periods. Recycled hens of all strains were heavier than 1st-yr hens. The onset of lay was earlier in H than B or N in both lay periods and all three strains had a delay in onset of lay after recycling. Through 23 wk photostimulation the B hens produced more eggs per hen than N or H hens (B > N > H) and recycled hens produced more eggs per hen than 1st-yr hens. Strain, year, and strain by year interaction effects were significant for egg weight. The first eggs laid, as well as subsequent eggs in both lay periods, were heaviest in N hens. In all strains, percentage yolk increased and albumen decreased with time in lay. However, N hens had a smaller percentage yolk and greater albumen than H or B hens. The mean percentage shell was greatest in H hens.

Analysis of Variance↗
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↗
PubMed2000

Attitudes of trained Swedish lay rescuers toward CPR performance in an emergency. A survey of 1012 recently trained CPR rescuers.

59 years old. Only 1% had attended the course because of their own or a relative's cardiac disease. Ninety-four per cent believed there was a minor to major risk of serious disease transmission while performing CPR. When predicting their willingness to perform CPR in six scenarios, 17% would not start CPR on a young drug addict, 7% would not perform CPR on an unkempt man, while 97% were sure about starting CPR on a relative and 91% on a known person. In four of six scenarios, respondents from rural areas were significantly more positive than respondents from metropolitan areas about starting CPR. In conclusion, readiness to perform CPR on a known person is high among trained CPR rescuers, while hesitation about performing CPR on a stranger is evident. Respondents from rural areas are more frequently positive about starting CPR than those from metropolitan areas.

Adult↗
PubMed1985

The effect of autoclaving and enzyme supplementation of guar meal on the performance of chicks and laying hens.

Four experiments with broilers and one with laying hens were conducted to study the effects of processing and hemicellulase supplementation of guar meal (37.0% protein) on growth, feed efficiency, and egg production. Guar meal at 0, 10, and 15%, either in raw form or autoclaved at 100, 102, or 132 C for 3, 15, or 30 min, was fed alone or in the presence of 0 to 250 ppm hemicellulase. In an experiment utilizing full-term broilers, 10 and 15% autoclaved guar meal was fed in the presence of lincomycin (3.3 ppm) or in combination with lincomycin and hemicellulase (25 ppm). The laying hen experiment was conducted with 36-week-old hens for 8 weeks. They were fed the raw or autoclaved meal (102 C, 15 min) alone and in combination with 30 ppm hemicellulase. The raw guar meal depressed growth and the depression was dose-related. Autoclaving at 102 C for 15 min increased growth and feed efficiency. A higher temperature or a longer time of autoclaving failed to give any further increase in growth or feed efficiency. The lowest (16.5 ppm) hemicellulase was as effective as the highest (250 ppm) in increasing growth and feed efficiency of chicks when added to guar meal diets. Penicillin had no effect on growth or feed efficiency when added to the diet containing autoclaved guar meal in the presence of hemicellulase. Dry heating at 150 C for 6 hr or water treatment of guar meal was not effective in stimulating growth or feed efficiency. Guar meal also increased stickiness of droppings; autoclaving enhanced the effect, whereas hemicellulase prevented the sticky droppings.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Analysis of factors affecting year-round performance of Single Comb White Leghorn laying hens reared under an open-sided housing system.

Based upon a field survey, an analysis was made to clarify factors affecting year-round performance of laying hens reared within an open-sided housing system. Data were collected from flocks located in Kumagaya city (36 degrees N, Japan), where they were subjected to periodic seasonal changes in photoperiod and ambient temperature specific to that area. Monthly performance of Single Comb White Leghorn laying hens at 5 to 16 mo of age was recorded and analyzed in terms of month of hatch, ambient temperature, and age. Changes in egg production and daily egg mass coincided with those in natural daylength. Egg weight was significantly lower in June-hatched layers; egg mass was highest in May and lowest in December hatches. Feed, CP, and ME intakes showed opposite periodic changes to that of ambient temperature with various delay times: ME intake showed no delay, whereas feed and CP intakes had 18 and 29-day delays, respectively. By comparing the performances of April to June and September to November-hatched hens, it was found that natural photoperiod appeared to be more important than ambient temperature in egg production, and that the effect of natural photoperiod became small and insignificant as the bird aged. The effect of temperature on egg production rate was found to be dependent on age of laying hens, i.e., it was more evident in old birds, especially when birds were exposed to a cold climate. Apparent age-dependent changes in the periodic element of egg production rate as related to calendar month were also shown.

Animals↗
PubMed2002

Genetic differences of Ascaridia galli egg output in laying hens following a single dose infection.

Groups of 20-week-old white (Lohmann LSL) and brown (Lohmann Brown) hens were reared under helminth-free conditions and both divided into two subgroups. One subgroup was artificially infected with 250 embryonated Ascaridia galli eggs, the other subgroup were kept as uninfected controls. During the following 12-month laying period individual faecal Ascaridia egg counts (FEC) were performed and bodyweight measured at monthly intervals. Laying performance and egg weights were determined daily. The mean FEC were significantly (P < 0.01) higher in infected white hens than in infected brown hens. The growth rate of the white hens was significantly (P < 0.05) higher in the control group, whereas in brown hens no significant group difference was observed. The laying performances and egg weights did not differ significantly (P > 0.05) between control and infected animals for either line. The estimated repeatabilities for mean log(10) FEC of different samples were reasonably high (0.16-0.54). Heritabilities for mean log(10) FEC were between 0.13 and 0.19 for white hens and between 0.0 and 0.10 for brown hens. Thus, it should be possible to select for A. galli resistance in chickens, which will be of importance for birds kept in alternative and organic farming systems.

Animals↗
PubMed1991

Comparison of the effects of synthetic and natural zeolite on laying hen and broiler chicken performance.

Three experiments were conducted to investigate the effect of zeolites on laying hens (Experiments 1 and 2) and broiler chickens (Experiment 3). Each experiment used corn and soybean meal-based practical diets. Experiment 1 was a 90-day trial and used 200 40-wk-old laying hens. The basal diet contained 2.75% calcium and .7% total phosphorus. The dietary treatments were the basal diet and the basal diet plus 1.5% synthetic zeolite (SZ; Ethacal). Experiment 2 was a 56-day trial and used 360 36-wk-old laying hens. The dietary treatments were .12, .22, .32, and .42% nonphytin phosphorus with and without 1.0% SZ and 1.0% natural zeolite (NZ; Zar-Min). All diets contained 3.5% calcium. Experiment 3 utilized 240 broiler cockerels from 1 to 16 days. The dietary treatments were two calcium levels (.65 and 1.0%) with and without 1.0% supplementary SZ and NZ. In Experiment 1, egg specific gravity was significantly increased with SZ supplementation. Egg weight and egg production were unaffected. Phytin phosphorus retention and plasma dialyzable phosphorus were significantly reduced by SZ. In Experiment 2, egg specific gravity was not affected by SZ or NZ. Egg weight, egg production, plasma dialyzable phosphorus, and the retention of phosphorus and phytin phosphorus were significantly reduced by SZ with the effect on egg weight and egg production being the most severe at the lower levels of dietary nonphytin phosphorus. Natural zeolite had no effect on egg weight, egg production, plasma calcium, plasma phosphorus, or on the retention of calcium, phosphorus, and phytin phosphorus. In Experiment 3, weight gain and percentage tibia bone ash were significantly reduced by SZ. The SZ had no effect on the incidence and severity of tibial dyschondroplasia. Weight gain, feed efficiency, and the incidence and severity of tibial dyschondroplasia were significantly reduced and the percentage bone ash significantly increased by 1.0% calcium. Natural zeolite significantly improved feed efficiency and had no effect on any other parameter measured.

Aluminum Silicates↗
PubMed1990

Effect of aluminum on performance and mineral metabolism in young chicks and laying hens.

This study was performed to determine the long-term effects of dietary aluminum on egg production and reproductive parameters in the mature laying hen and on growth rate and feed efficiency in young chicks. The diets used in these studies were adequate in phosphorus and other essential nutrients. Aluminum added to constitute 0.30% of the diet severely depressed growth and reduced feed efficiency, bone ash and plasma phosphorus in male Ross x Leghorn chicks. At the same time, 0.15% added aluminum mildly depressed growth, feed efficiency and bone ash but had no effect on plasma phosphorus levels. The reduction in bone ash was relatively mild, and no clinical signs of rickets were observed. In laying hens, diets containing 0.15% added aluminum did not affect egg production, but 0.30% added aluminum reduced production significantly. Long-term exposure to aluminum increased percent shell in both groups receiving aluminum, whereas egg weight remained similar to that in controls. There were no changes in hatchability or bone ash associated with dietary aluminum. Although dietary aluminum influenced bone aluminum content, egg aluminum content was not affected. These studies indicate that dietary aluminum interferes with systems in addition to phosphorus metabolism.

Aluminum↗
PubMed2003

The effect of different levels of nonphytate phosphorus with and without phytase on the performance of four strains of laying hens.

A 4 x 7 factorial experiment was conducted to determine the effect of different nonphytate phosphorus (NPP) regimens with and without phytase on performance of four strains of laying hens. The strains used were Babcock B300, DeKalb Delta White, Hy-Line W36, and ISA-White. The birds of T1 (Treatment 1), control diet, were fed a diet with 0.45% NPP for the entire experiment (20 to 63 wk of age). The birds of T2 were fed a NPP regimen of 0.25% for Phase 1 (20 to 35 wk of age), 0.2% for Phase 2 (36 to 51 wk of age), and 0.15% for Phase 3 (52 to 63 wk of age). The birds of T3 and T4 were fed a NPP regimen similar to T2 plus 150 or 300 units phytase/kg diet, respectively. The birds of T5 were fed a NPP regimen of 0.2, 0.1, and 0.1% for Phases 1, 2, and 3, respectively. The birds on T6 and T7 were fed a NPP regimen similar to T5, with 150 and 300 units phytase/kg diet, respectively. The criteria for evaluating the effect of dietary treatments were production performance, shell quality, bone ash, and total P excretion. Production traits were drastically reduced and mortality was drastically increased when the birds of T5 were fed a diet with 0.1% NPP during Phase 2 (36 to 51 wk of age). Increasing the NPP level of this treatment from 0.1 to 0.45% during Phase 3 restored the production traits almost to the control level during this phase of the experiment. The NPP regimen of 0.2-0.1-0.1% plus either level of phytase (T6 and T7) restored most of the traits for the entire experiment to the control level (T1), except egg production (EP) and the nonprolapse mortality. Bone ash also remained significantly lower than the control group with this NPP regimen plus the higher level of phytase (T7). Production traits were reduced, and nonprolapse mortality was increased due to the use of a NPP regimen of 0.25-0.2-0.15% without phytase (T2) for the entire experiment. The NPP regimen of 0.25-0.2-0.15% plus the lower level of phytase (T3) restored all the traits except EP to the control level for the entire experiment. The only treatment that maintained performance of all the strains comparable to their controls for the entire experiment was a NPP regimen of 0.25-0.2-0.15% plus the higher level of phytase (T4). Total P excretion of birds fed this NPP regimen was reduced by 55.6% as compared to the control group. The data generally indicated that the higher level of phytase was more effective than the lower level in restoring the performance of birds fed the low-P diets to the control level. Numerous interactions existed among strain x diet for various traits throughout the experiment, indicating the NPP requirement for maintaining production performance may be different among strains.

6-Phytase↗
PubMed2004

Effects of supplemental L-carnitine in drinking water on performance and egg quality of laying hens exposed to a high ambient temperature.

The present study was conducted to investigate effects of L-carnitine supplied with drinking water on performance and egg quality of laying hens under high environmental temperature. In the study, 47-week-old laying hens (Brown hisex) were divided into two groups (control and treatment) and fed with a standard layer diet. Treatment group was received 50 p.p.m L-carnitine with drinking water for an 8-week period. Throughout the study, 8 h hot (35-37 degrees C) and 16 h thermoneutral (20-22 degrees C) environmental temperature regime was employed daily. The results showed that L-carnitine supplementation affected some egg quality characteristics of layers under high environmental temperature. Relative albumen weight and height were increased (p < 0.05) by supplemental L-carnitine. Live weight gain, feed intake, egg mass, egg weight, yolk weight, shell weight, yolk index, egg-shape index, yolk colour score and shell thickness were not affected (p < 0.05) by L-carnitine. It is concluded that L-carnitine supplementation in laying hens could have potential to improve albumen quality under high environmental temperature.

Animals↗
PubMed1983

Benefits of low sodium in the diets of laying hens during the period prior to forced rest.

Two experiments were conducted to study the performance of laying hens when sodium chloride and dicalcium phosphate were removed from the diet for 4 days before beginning the forced rest treatment. Calcium level of the diet was increased 2.4%. When the sodium was removed from the diet, hens laid 3.3 and 1.9 more eggs before going out of production in Experiment 1 and 2, respectively, than hens from which the feed was removed on Day 1. The performance of the hens following the resting period was not influenced by removing the salt from the diet in the prerest period (Days 0 to 4). Egg weight and specific gravity were not affected.

Animals↗
PubMed1993

Citizen response to cardiopulmonary emergencies.

Since 1985, it has become apparent that the key to survival from adult sudden cardiac death is prompt defibrillation. Any delay from the time of collapse to the initial countershock will decrease the likelihood of survival. It also has been determined that CPR performed by lay rescuers is not begun promptly and, once started, often is performed for more than one minute before the emergency medical services (EMS) system is accessed, which significantly delays the time to defibrillation. In adults, therefore, the rescuer should phone first to activate the EMS system before performing CPR. In the pediatric population, respiratory arrests are far more common than cardiac arrests. Therefore, a rescuer should perform one minute of rescue support before activating the EMS system (a concept termed phone fast). It is recognized that this change is dependent upon a national EMS system that is still evolving. It is hoped that this change to phone first and phone fast will provide an impetus for rapid development of the EMS infrastructure.

Cardiopulmonary Resuscitation↗
PubMed2003

Performance of two strains of laying hens fed ground and whole barley with and without access to insoluble grit.

The live performance from 19 to 43 wk of age of two strains of commercial White Leghorn hens fed two levels of whole barley (0 or 60%) and insoluble grit (0 or 4 g/bird per wk) was compared. The 0 and 60% whole barley diets differed only in feed form and were formulated to the same nutrient specifications. No dilution of nutrients or ingredients occurred. The 0% whole barley diet was fed in mash form. The 60% whole barley diet was fed as whole grain and mash concentrate blended into a complete diet and fed in the same feed trough. Feeding whole barley reduced egg production, feed efficiency, and egg specific gravity and increased feed intake, egg weight, and body weight gain. Access to insoluble grit had no effect on any of the production variables measured. The two strains of hens responded similarly to whole barley but differed in feed intake, feed efficiency, egg weight, egg specific gravity, and body weight gain. Feeding whole barley combined with a mash concentrate depressed hen performance compared to birds fed a similar diet in mash form. Strain of hen and access to insoluble grit did not alter the response to feeding whole barley.

Animal Nutritional Physiological Phenomena↗
PubMed2005

Effects of feed-borne Fusarium mycotoxins on hematology and immunology of laying hens.

Feeding grains naturally contaminated with Fusarium mycotoxins has been shown to alter metabolism and performance of laying hens. The objectives of the current experiment were to examine the effects of feeding grains naturally contaminated with Fusarium mycotoxins on hematology and immunological indices and functions of laying hens and the possible protective effect of feeding a polymeric glucomannan mycotoxin adsorbent (GMA). One hundred forty-four laying hens were fed for 12 wk with diets formulated with (1) uncontaminated grains, (2) contaminated grains, or (3) contaminated grains + 0.2% GMA. Fusarium mycotoxins such as deoxynivalenol (DON, 12 mg/kg), 15-acetyl-DON (0.5 mg/kg), and zearalenone (0.6 mg/kg) were identified in the contaminated diets arising from contaminated grains grown in Ontario, Canada. The concentrations of DON arising from naturally contaminated grains in this study were similar to purified mycotoxin fed to experimental mice. The chronic feeding of Fusarium mycotoxins induced small decreases in hematocrit values, total numbers of white blood cells, lymphocytes including both CD4+ and CD8+ T lymphocytes and B lymphocytes, and biliary IgA concentration. Supplementation of diets containing feedborne mycotoxins with GMA prevented the reduction in total number of B lymphocytes in the peripheral blood and the reduction in biliary IgA concentration. In addition, the delayed-type hypersensitivity response to dinitrochlorobenzene was increased by feed-borne mycotoxins, whereas IgG and IgM antibody titers to sheep red blood cells were not affected by diet. We concluded that chronic consumption of grains naturally contaminated with Fusarium mycotoxins at levels likely to be encountered in practice were not systemically immunosuppressive or hematotoxic; however, mucosal immunocompetence needs to be explored further.

Animal Feed↗