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PubMed1987

Production, physiological, and behavioral responses of laying hens in different management environments.

Responses of commercial laying hens to 16 management systems were examined for 10 laying periods of 28 days each. Twelve cage treatments consisted of housing three, four, or five hens in deep and shallow cages of different dimensions which provided .035 and .046 m2/hen. Four floor treatments housed 35 hens or 32 hens and three roosters at densities of .094 or .373 m2/bird, in two replicated pens each. Quantitative data were collected simultaneously for 23 production, physiological, and behavioral characteristics throughout the study. When comparing all caged with floor pen hens, caged hens had better (P less than .05) egg production rates (76.3 vs. 73.9%), gained more weight, had better feed efficiency, and had greater egg and egg shell weights than floor hens. All floor pen hens had higher (P less than .01) viability (98.9 vs. 95.0%), higher (P less than .01) plasma corticosterone levels (595.0 vs. 445.4 pg/ml), a greater (P less than .01) response to adrenocorticotropin (ACTH) challenges, and lower (P less than .01) antibody titers to Salmonella pullorum challenges than all caged hens. Caged hens preened, stood, crouched, and feather pecked more than floor hens, while floor hens drank and moved about more than caged hens. This study attempted to quantify production, physiological, and behavioral traits, all on the same flock of hens, in order to separate stressful from nonstressful management environments. Integration of all measurements indicates that properly managed caged hens were subjected to significantly fewer stressors than laying hens housed in floor pens, although the hens' well-being in the two environments could not be quantitatively compared.

Animals↗
PubMed1987

Water balance in incubating turkey eggs.

The eggshell water vapor conductance capable of maintaining constant water content in incubating turkey eggs was determined for three different egg weight classifications. Metabolism of the developing turkey embryos was altered by increasing or decreasing eggshell permeability. Eggshell permeability accommodated metabolic water in large eggs very well. Both relative poult weights and relative water content of embryos in large eggs at the plateau stage in oxygen consumption decreased or increased allometrically to the permeability treatment. However, among small and medium eggs, if eggshell permeability was increased, relative poult weights at hatching were much less than expected. This occurred despite the fact that relative water content of the eggs at 25 days of incubation was not similarly affected. The data suggest a biological asynchrony for egg size, metabolism, and water content of turkey eggs.

Animals↗
PubMed1988

Influence of 1,25-dihydroxyvitamin D3 on the performance of commercial laying hens.

An experiment was conducted to determine the influence of adding 4 micrograms/kg of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] to the diet of 68-wk-old commercial egg production-type hens. The addition of the 1,25(OH)2D3 to the diet for 21 days resulted in significantly decreased egg production, egg weight, and feed consumption, and significantly increased plasma P, and bone-breaking load. Specific gravity of eggs, plasma Ca, tibia ash, and fertility and hatchability of eggs were not significantly affected by the addition of 1,25(OH)2D3 to the diet.

Animals↗
PubMed1989

Bactericidal activity, eggshell conductance, and hatchability effects of ozone versus formaldehyde disinfection.

Ozone and formaldehyde were evaluated as disinfectants in a prototype laboratory setter against microorganisms that are naturally present on fertile, freshly laid, broiler hatching eggs. Significantly lower microbial counts of over 2.5 log10 (P less than .05) were observed for water-misted and ozonated (2.83% by weight) eggs or formaldehyde-fumigated (triple strength) eggs than for control and water-misted eggs. Eggshell conductance studies as measured by egg moisture losses in a desiccator showed no significant differences (P greater than .05) among untreated, water misted, ozonated (3.06% by weight) with water mist, or formaldehyde (triple strength)-fumigated eggs. Hatchability was significantly reduced (26.5 to 37.5%) following ozonation (3.03% ozone by weight, 2 h) in comparison with effects of no treatment or water misting. Misting with ozonation was equally as effective as formaldehyde fumigation in reducing microbial counts. However, ozone treatment at the concentrations tested significantly reduced hatchability when compared with results of either no treatment, water misting, or an average hatchability figure for formaldehyde fumigation. These findings indicate that ozone is a good disinfectant yet may adversely affect embryo development when given in the gaseous form.

Animals↗
PubMed1989

Laying performance and fear response of White Leghorns as influenced by floor space allowance and group size.

Three experiments were conducted with White Leghorn pullets housed in litter-floored pens to determine the effects of floor space allowance and group size on laying performance and fear response. In Experiment 1, 17 birds were housed at a floor space allowance of .40 or .29 m2/bird. In Experiment 2, 22 or 16 birds were housed at a floor space allowance of .31 m2/bird. The following treatments were used in Experiment 3:1) 26 birds per pen at .19m2/bird, 2) 36 birds per pen at .19 m2/bird, and 3) 26 birds per pen at .26 m2/bird. The test period was from 20 to 52 wk of age in each experiment. Duration of the induced tonic immobility, measured at 52 wk of age, was used as a criterion of fearfulness. Decreasing floor space allowance per bird, increasing group size per pen or a combination of the two had no significant effect on final body weight, hen-day egg production, feed efficiency, egg weight, albumen height, or fearfulness of the bird. Decreasing floor space per bird while holding the number of birds per pen constant significantly (P less than .05) increased mortality. Birds given less floor space consumed significantly (P less than .05) more feed than birds given more floor space in Experiment 1. This study indicates that the birds' hen-day egg production, feed efficiency, and fearfulness are not significantly (P greater than .05) influenced by floor space allowance or group size and that effects of floor space allowance and those of group size are not additive.

Analysis of Variance↗
PubMed1990

Behavior, production, and well-being of the laying hen. 1. Effects of movable roosts, relationship of cage mates, and genetic stock.

The effects of movable roosts, relationship of cage mates (siblings versus nonsiblings), and genetic stock on measures of behavior, production, and physical condition were investigated. Sibling and nonsibling pairs of hens derived from two male parental stocks (designated MPS1 and MPS2) were randomly assigned to two cage batteries (384 hens total). The batteries were identical except that the cages of one had individual wood roosts, which were automatically raised at night and lowered the next morning. The laying phase comprised 13 28-day periods. On the first 4 days of Periods 1, 3, 5, 7, 9, and 11, video recordings were made of 8 cages per day. Video-recorded data for Period 5 were discarded, however, because equipment failure caused an unplanned photoperiod ratio. Direct visual observations were carried out in Period 13. Egg production and feed consumption were recorded in each period. Feather scores were determined in Periods 3, 6, 9, and 12, and in Periods 6 and 13, hens were weighed and the number of lesions to the feet counted. Overall, roosts appeared to improve well-being. Resting occurred more in cages with roosts, feathering was better initially, body weights were slightly higher, and foot lesions were were fewer. Egg production was not affected except that egg cracks were more frequent in roosts cages. Relationship of cage mates had relatively little influence. However, in conventional cages, nonsiblings manifested more bobbing behavior, and in MPS1, nonsiblings had higher feed consumed per dozen eggs. Hens of MPS1 performed more head flicking, drinking, physical displacement, aggression, and cage wall climbing than MPS2 hens. They also had higher egg production, weaker egg shells, poorer feathering, and more lesions to the feet. The genetic stock differences suggest that hens of MPS1 experienced poorer well-being. None of the treatments significantly affected mortality.

Animals↗
PubMed1991

Influence of sodium aluminosilicate, hydroxy-sodalite, carnegieite, aluminum sulfate, and aluminum phosphate on performance of commercial Leghorns.

Experiments were conducted to determine if the high ion-exchange capacity of sodium aluminosilicate (ZA) marketed as ETHACAL Feed Component or its aluminum content or both are related to the beneficial effect of ZA on egg specific gravity (ESG). In Experiments 1 and 2, ZA was compared with hydroxy-sodalite (HS) and carnegieite, which have the same chemical formula as ZA but little or no ion-exchange capacity. Two levels of ZA (0 and 1.5% of the diet) and three levels of HS (0, .75, and 1.5%) were fed in Experiment 1. In Experiment 2, 0, .75, and 1.5% of ZA and carnegieite were fed. In Experiment 3, ZA, carnegieite, aluminum sulfate, and aluminum phosphate were fed at levels calculated to contain .148 and .101% aluminum. Criteria evaluated were ESG, egg production, feed consumption, and egg weight. Egg specific gravity was significantly improved by ZA in all experiments and was not affected by HS, carnegieite (Experiments 1 and 2), aluminum sulfate (.148% Al), or aluminum phosphate (Experiment 3). Carnegieite and aluminum (.101%) from aluminum sulfate increased ESG in Experiment 3. In Experiments 1 and 3, egg production and feed consumption were not influenced by various treatments. Carnegieite and ZA reduced egg production and feed consumption in Experiment 2. It was concluded that the ion-exchange capacity and aluminum content of ZA may contribute to its beneficial effect on ESG.

Alum Compounds↗
PubMed1991

The influence of various calcium and phosphorus levels on tibia strength and eggshell quality of pullets during peak production.

One thousand and eighty DeKalb XL pullets were randomly allocated to nine treatments and arranged in a 3 x 3 factorial to determine the effects of three levels of dietary calcium (2.75, 3.75, and 4.25%) and three levels of dietary available phosphorus (.30, .40, and .50%) on eggshell quality and tibia weight, tibia breaking strength, tibia ash, and bone mineral content of pullets during peak production. Feed consumption increased as dietary calcium or phosphorus increased. Increasing dietary calcium caused a significant linear increase in egg specific gravity, but dietary phosphorus had no significant effect on egg specific gravity. Calcium and phosphorus levels did not significantly affect egg production, body weight, plasma chloride, or phosphorus. Ionized calcium increased significantly as dietary calcium increased. Tibia breaking strength, tibia weight, tibia ash, and bone mineral content increased significantly with increasing dietary calcium. Dietary phosphorus had no significant effect on these parameters. However, when 2.75% calcium was fed, reducing dietary phosphorus significantly decreased tibia weight, tibia ash, and bone mineral content.

Animals↗
PubMed1991

Effects of selection for growth and selection diet on eggshell quality and embryonic development in Japanese quail.

Decreased hatchability in Japanese quail following selection for growth and relative improvements in hatchability following selection during goitrogen treatment were investigated. An unselected quail line (Line C) and lines selected for high 4-wk body weight while being fed diets containing either 20% CP and .2% thiouracil (TU) (Line T), or 28% CP and no TU (Lines P and H-CD) were used. Egg weight loss between 0 and 4, and 0 and 14 days of incubation, hatchability, and developmental stage of embryonic mortalities were determined in Experiment 1. Length of the incubation period, and percentages of body water and dry body weight were determined for 10- and 14-day embryos and 18-day-old chicks in Experiment 2. Eggshell quality was determined in Experiment 3. Hatchability was lower in selected than in unselected quail due to increased early and late embryonic mortality. Egg weight loss during incubation was greater in Line P than in Line C eggs. Weight loss, measured across lines, was lower in eggs that hatched than in those in which embryos died early. Percentage body water was higher in Line C than in Lines P and T at 14 and 18 days of incubation; however, percentage body water in Line T was lower than Line P at 14 days. Percentage of dry body weight was greater in Lines P and T than in Line C at 14 and 18 days. Eggshell thickness was greater in Line H-CD when compared with Line C. Increases in eggshell permeability occurring during selection for growth were associated with increased embryonic mortality and decreased hatchability.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Effectiveness of zinc bacitracin on production traits and energy metabolism of heat-stressed hens compared with hens kept under moderate temperature.

Two experiments with a total of 100 White Leghorn hens (26 to 59 wk of age) and 120 Rhode Island Red chickens (4 to 12 wk of age) were conducted to study the effect of 100 mg zinc bacitracin (ZBA)/kg of feed on hens and chickens acclimatized to 20 or 34 C environments. Layers were provided ad libitum access to a diet containing 11.12 MJ ME/kg (1 MJ = .239 Mcal) and 174 g CP/kg supplemented with 0 and 100 mg ZBA/kg. Body weight gain, egg number, total egg mass, and feed efficiency of ZBA-treated hens kept at a moderate temperature (20 C) were not significantly improved by 3.5, 2.6, 3.3, and 3.1%, respectively. However ZBA supplementation induced a more pronounced increase in performance in heat-stressed hens. The respective traits were significantly improved by 66.3, 15.4, 16.9, and 5.9%. Additionally, treated hens maintained at 34 C consumed significantly more feed than untreated hens. Eggshell breaking strength of treated hens held under normal conditions was not significantly improved. Feeding ZBA to heat-stressed hens led to a statistically higher breaking strength. Supplementation with ZBA for hens acclimatized to 20 and 34 C reduced fasting heat production by 4.1 and 7.6%, respectively. However, in the 20 C environment the differences were significant at only one of seven ages. The upper critical temperature (UCT) of ZBA-treated hens increased significantly at both temperatures from 34 to 42 wk of age relative to the control group. No significant effects of ZBA on UCT were observed at 24 to 32 wk and 40 to 52 wk of age.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Influence of protein concentration, amino acid supplementation, and daily time to access to high- or low-protein diets on egg weight and components in laying hens.

Feeding a 13% CP diet based on corn and soybean meal and supplemented with methionine to laying hens results in reduced egg weight in comparison with hens fed a corn and soybean meal methionine-supplemented diet containing 16% CP. An experiment was conducted to determine whether the egg weight reduction could be eliminated by supplementing the low-protein diet with additional lysine, methionine, and tryptophan or by adding glycine and glutamic acid to increase the amino nitrogen to a level equivalent to 16% CP. The influence of the dietary treatments on the weight of the major egg components was also determined. In a second experiment, the influence of time of day of feeding the 13 or 16% CP diets on egg weight and egg components was determined. Adding additional amino nitrogen in the form of glycine and glutamic acid or increasing the levels of lysine, methionine, or tryptophan individually or in combination failed to prevent the depression in egg weight of hens fed the lower protein diet. Measurement of egg components demonstrated that the reduction in egg weight was primarily associated with a reduction in albumen content of the egg. Feeding a high-protein diet from 1400 to 0800 h and a low-protein diet from 0800 to 1400 h resulted in egg weight equivalent to that from hens continuously fed the high-protein diet. The lower weight of the albumen in eggs from hens fed a 13% CP diet may be due to a lower availability of amino acids for protein synthesis during the 3- to 4-h period when the ovum is in the magnum.

Amino Acids↗
PubMed1992

Effect of duration of fasting on postmolt laying hen performance.

Two experiments were conducted to examine the effects of varying length of feed withdrawal on postmolt laying hen performance. Commercial laying hens (65 wk of age) were fed continuously or fasted for 4 or 10 days in Experiment 1 and fed continuously or fasted for 4, 7, or 14 days in Experiment 2. Egg production performance was evaluated for 35 wk of production following initiation of fasting. Hen-day egg production (Weeks 1 to 35) and egg weight (Weeks 5 to 35) did not differ between treatments in Experiment 1; however, in Experiment 2, egg production was depressed for the 14-day fasted hens compared with the fed hens. Lower egg weight also occurred for the 14-day fasted hens compared with the fed, 4-, or 7-day fasted hens in Experiment 2. Egg yield (grams of egg per hen per day) for Weeks 5 to 35 was lower for fed hens versus the 4- or 10-day fasted groups in Experiment 1, but no treatment differences occurred in Experiment 2. Feed efficiency (grams of egg per gram of feed) for Weeks 5 to 13 was not affected by length of fasting in Experiment 1, but feed efficiency of hens fasted for 14 days was lower (P less than .05) than that of hens on other treatments in Experiment 2. Egg specific gravity was highest for hens fasted for 10 or 14 days and was lowest for fed hens, with egg specific gravity for hens fasted for 4 or 7 days being intermediate (P less than or equal to .05). The results indicated that fasting periods of less than 10 days may yield satisfactory egg production and egg weight but that eggshell quality may be enhanced by using fasting periods of 10 days or longer.

Animals↗
PubMed1992

Effects of ascorbic acid on plasma thyroxine concentrations and eggshell quality of Leghorn chickens treated with dietary thiouracil.

Because ascorbic acid (AA) and the thyroid hormones are known to influence eggshell formation, the effects of AA on body weight, total plasma thyroxine (T4), egg production, and eggshell quality of Single Comb White Leghorn (SCWL) hens concurrently and previously treated with thiouracil (TU) were determined. Hens were provided feed containing either 0 or 100 ppm AA from 47 to 67 wk of age and either 0 or .1% TU from 47 to 57 wk of age. A three-way split-plot analysis was employed to test for the effects of AA, TU, and time, and their interactions. Dietary TU increased body weight between 53 and 59 wk, and increased thyroid weight at 67 wk; however, TU only depressed plasma T4 level at 51 wk. Dietary TU depressed egg production from 50 to 56 wk and egg weight at 49, 51, and 57 wk. Dietary TU depressed eggshell weight per unit surface area at 49 wk. There was no significant effect due to AA and no AA by TU interaction for any of the parameters examined. It was concluded that .1% dietary TU from 47 to 57 wk of age did not alter eggshell quality and that dietary AA at the 100 ppm level did not influence the effects of .1% TU on body weight, egg production, or egg weight of SCWL hens.

Animals↗
PubMed1992

Zinc methionine for stressed laying hens.

The effects of zinc methionine product (ZP) supplementation to Single Comb White Leghorn hens on egg production and quality were measured through three consecutive egg laying cycles. During the first and second lay cycles, ZP had minor or nonsignificant effects upon hen performance. During the third lay cycle, a low dietary Ca (.3% Ca) stress of 1 mo duration was encountered. During this low-Ca stress period, hens fed 1 g ZP/kg produced the greatest number of eggs (P less than .05), and during recovery from that low-Ca stress, the hens receiving 2 g ZP/kg produced the most eggs (P less than .05). The ZP appeared to help hens maintain egg size throughout this stress period. The present results indicate that ZP was beneficial to hens during low-Ca stress and during the recovery period following that stress.

Animals↗
PubMed1992

The effect of sodium zeolite A and cholecalciferol on plasma levels of 1,25-dihydroxycholecalciferol, calcium, and phosphorus in commercial Leghorns.

Three experiments were conducted to determine possible mechanisms involved in improving eggshell quality with sodium zeolite A (SZA) (trade name Ethacal feed component), and cholecalciferol (vitamin D3) by studying the effect of dietary supplementation of SZA and vitamin D3 on plasma 1,25-dihydroxycholecalciferol [1,25-(OH)2 D3], ionic calcium (Ca++), normalized calcium (nCa++), total calcium (TCa), percentage Ca++ to TCa (PCa++), pH, and phosphorus (P). In Experiment 1 (2 x 2 factorial arrangement of treatments), two levels of SZA (0 and .75%) and two levels of vitamin D3 (0 and 175 ICU/kg) were fed. In Experiment 2, five levels of vitamin D3 (100 to 500 ICU/kg) and two levels of SZA (0 and .75%) were fed using a 2 x 5 factorial arrangement of treatments. In Experiment 3, hens were fed two levels of SZA (0 and .75%). Blood samples were collected at 0 (Experiments 1, 2, and 3), 7, 14, and 21 h (Experiment 3) postoviposition (POP). In Experiments 1 and 2, decreasing vitamin D3 decreased plasma 1,25-(OH)2 D3 and P. Plasma TCa decreased when 0 ICU vitamin D3 was fed (Experiment 1), but was not affected by vitamin D3 level in Experiment 2. Supplemental SZA had no effect on plasma 1,25-(OH)2 D3, TCa, or P in Experiments 1 and 2. In Experiment 3, plasma 1,25-(OH)2 D3 and P peaked at 14 h POP, but Ca++ was lowest at 14 h POP. Circadian rhythms for plasma 1,25-(OH)2 D3, Ca++, and P were not affected by SZA. There were no significant effects due to dietary SZA on plasma 1,25-(OH)2 D3, TCa, Ca++, PCa++, nCa++, pH, or P.(ABSTRACT TRUNCATED AT 250 WORDS)

Aluminum Silicates↗
PubMed1994

Effects of dietary thiouracil on thyroid activity, egg production, and eggshell quality in commercial layers.

The effects of thyroid suppression induced during the rearing period by providing various dietary thiouracil (TU) regimens on plasma thyroxine (T4) concentrations, growth, and subsequent egg production (EP) and eggshell quality were determined in Single Comb White Leghorn chickens. Thiouracil was provided in the feed at levels of 0, .1, and .2% from 0 to 6 wk of age in Experiment 1, and at levels of 0, .05, and .1% from 6 to 16 wk of age in Experiment 2. In both experiments, T4 concentrations were reduced during TU treatment. However, T4 later became elevated at 12 and 20 wk in both dosage level groups in Experiment 1. Additionally, BW and egg weights were suppressed by both TU treatments, and EP was reduced up to Week 23 in the .1% TU-treated birds and through Week 25 in the .2% TU-treated birds. No effects on EP were noted in Experiment 2, but feed consumption (FC) was reduced during Week 6 in birds fed .05% TU and during Weeks 6, 10, and 19 in birds fed .1% TU. Both liver and thyroid weights were increased in .1% TU-treated birds relative to controls at Week 16. Eggshell quality was affected only in Experiment 2, in which birds given .05% TU had a higher relative conductance, or maximum rate of water loss, at Week 38 than 0 and .1% TU dosage levels, and .1% TU-treated birds had a higher breaking strength than 0 and .05% TU-treated birds at Week 22.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1995

Yolk thiobarbituric acid reactive substances and n-3 fatty acids in response to whole and ground flaxseed.

n-3 fatty acid (FA)-enriched shell eggs have been proposed as an economical source for increasing consumption of n-3 FA. As dietary n-3 FA sources vary with respect to fatty acid profile and lipid stability, the comparison of resulting egg products is warranted. This study was designed to determine yolk thiobarbituric acid reactive substances (TBARS) and n-3 FA when hens were fed whole or ground flaxseed. Gold flaxseed (whole or ground) fed at levels of 5 or 15% were compared to a 1.5% menhaden oil or a typical control layer ration. A 5-wk feeding trial was used with 21 hens per treatment. Eggs were collected and FA composition determined during Weeks 4 and 5 of the feeding trial. The TBARS content of yolk was also determined. All flaxseed treatments increased total n-3 FA (C18:3 + C20:5 + C22:6) marine n-3 FA (C20:5 + C22:6) did not increase proportionately with increasing dietary flaxseed. Seed form did not influence n-3 FA deposition at the 5% level of flaxseed; however, ground 15% flaxseed resulted in greater total n-3 FA deposition than whole 15% flaxseed. Yolk TBARS were not different due to diet, indicating that seed form did not influence the oxidative quality of these n-3 FA-rich lipids.

Analysis of Variance↗
PubMed1996

Effect of hatching cabinet sanitation treatments on Salmonella cross-contamination and hatchability of broiler eggs.

Four trials were conducted to evaluate the efficacy of hatcher air sanitation utilizing ultraviolet light (UV), ozone, or hydrogen peroxide on bacterial populations, the spread of Salmonella, and hatchability of broiler eggs. The UV light (254 nm, 146 mu W/s) and ozone (0.2 or 0.4 ppm) treatments were continuously applied through the last 3 d of hatch, the hydrogen peroxide treatment (2.5%) was administered 1 or 2 min of each 10 min at rates of 500 or 100 mL/h. Hatchability was not significantly reduced by sanitizing treatments when compared with the untreated control (94 vs 95.6%). As compared to controls, all sanitizing treatments reduced 75 to 99% of the total bacteria, Enterobacteriaceae, and Salmonella in the hatching cabinet air samples. The use of hydrogen peroxide resulted in greater reduction of bacteria than ozone or UV light. Only hydrogen peroxide significantly reduced Salmonella levels on eggshell fragments. Significant reductions in the number of Salmonella-positive chicks occurred using the ozone and hydrogen peroxide treatments. Hydrogen peroxide significantly reduced the magnitude of Salmonella colonization in chicken ceca. These trials demonstrated that the spread of bacteria can be effectively reduced in the hatching cabinet by air sanitization using UV light, ozone, and hydrogen peroxide. The potential to reduce bacterial cross contamination in the hatcher is achievable without depressing hatchability.

Air Pollution, Indoor↗