Guar meal diets as an alternative approach to inducing molt and improving Salmonella enteritidis resistance in late-phase laying hens

Induced molting of laying hens is a practice used by commercial egg producers to increase the productive lifetime of their flock. However, the conventional method of inducing molt, which involves removal of feed, water, or both as well as a reduction in photoperiod to less than a natural day has drawn criticism due to animal welfare and food safety concerns. The objective of this study was to explore the efficacy of diets containing high levels of guar meal (GM) in inducing molt and reducing susceptibility to Salmonella Enteritidis colonization in late-phase laying hens. Late-phase (68 wk old) Lohmann laying hens were either full-fed standard laying hen diets (nonmolted control), induced to molt by feed withdrawal, or full-fed standard laying hen diets containing 20% GM with or without 250 units/kg of mannanase Hemicell supplementation. On the fourth day of treatment, all hens were orally challenged with SE (1.65 x 10(7) cfu). Hens were killed and evaluated for Salmonella colonization and differences in organ weights 5 d postinoculation. Salmonella Enteritidis present in crop, liver, ovary, and cecal contents were significantly reduced by feeding GM with enzyme supplementation compared with feed withdrawal hens. No significant differences were observed in reproductive tract weights of molted groups, although a difference in liver weight was detected. Results indicate that feeding diets containing 20% GM are as effective as complete feed withdrawal with respect to inducing molt with the added benefit of improved resistance to Salmonella Enteritidis colonization and translocation.

Use of guar by-products in high-production laying hen diets

A 5x5 Latin square experiment was conducted to evaluate the effect of feeding low concentrations of guar germ or a combination of guar germ and hull (guar meal) in high-production laying hen diets. A total of 125 Lohmann laying hens (21 wk old) of similar BW were randomly assigned to 5 blocks. Each block was divided into 5 experimental units, consisting of 5 hens per unit. Hens were fed either a nonguar control diet, or 1 of 4 diets containing either 2.5 or 5% guar germ, or 2.5 or 5% guar meal over a 20-wk trial period (five 4-wk periods). No significant differences were observed when feeding either 2.5 or 5% guar germ or meal (P>0.05) on hen-day egg production or feed consumption. Significant differences in egg weight, total egg mass per hen, and feed conversion ratio were detected in hens fed 2.5% guar meal, whereas they remained unchanged for diets containing either level of guar germ or 5% guar meal. Feeding either level of guar germ or guar meal did not affect shell quality (shell thickness, egg breaking force, and specific gravity), Haugh units, or egg yolk color (L*, a*, b*). The results showed that both guar germ and guar meal can be fed to high-production laying hens at up to 5% without adverse effects on laying hen performance.

Nitrogen emissions from broilers measured by mass balance over eighteen consecutive flocks

Emission of nitrogen in the form of ammonia from poultry rearing facilities has been an important topic for the poultry industry because of concerns regarding the effects of ammonia on the environment. Sound scientific data is needed to accurately estimate air emissions from poultry operations. Many factors, such as season of the year, ambient temperature and humidity, bird health, and management practices can influence ammonia volatilization from broiler rearing facilities. Precise results are often difficult to attain from commercial facilities, particularly over long periods of time. Therefore, an experiment was conducted to determine nitrogen loss from broilers in a research facility under conditions simulating commercial production for 18 consecutive flocks. Broilers were reared to 40 to 42 d of age and fed diets obtained from a commercial broiler integrator. New rice hulls were used for litter for the first flock, and the same litter was recycled for all subsequent flocks with caked litter removed between flocks. All birds, feeds, and litter materials entering and leaving the facility were quantified, sampled, and analyzed for total nitrogen content. Nitrogen loss was calculated by the mass balance method in which loss was equal to the difference between the nitrogen inputs and the nitrogen outputs. Nitrogen partitioning as a percentage of inputs averaged 15.29, 6.84, 55.52, 1.27, and 21.08% for litter, caked litter, broiler carcasses, mortalities, and nitrogen loss, respectively, over all eighteen flocks. During the production of 18 flocks of broilers on the same recycled litter, the average nitrogen emission rate was calculated to range from 4.13 to 19.74 g of N/ kg of marketed broiler (grams of nitrogen per kilogram) and averaged 11.07 g of N/kg. Nitrogen loss was significantly (P < 0.05) greater for flocks reared in summer vs. winter. Results of this experiment have demonstrated that the rate of nitrogen volatilization from broiler grow-out facilities varies significantly on a flock-to-flock basis.

Measurement of broiler litter production rates and nutrient content using recycled litter

It is important for broiler producers to know litter production rates and litter nutrient content when developing nutrient management plans. Estimation of broiler litter production varies widely in the literature due to factors such as geographical region, type of housing, size of broiler produced, and number of flocks reared on the same litter. Published data for N, P, and K content are also highly variable. In addition, few data are available regarding the rate of production, characteristics, and nutrient content of caked litter (cake). In this study, 18 consecutive flocks of broilers were reared on the same litter in experimental pens under simulated commercial conditions. The mass of litter and cake produced was measured after each flock. Samples of all litter materials were analyzed for pH, moisture, N, P, and K. Average litter and cake moisture content were 26.4 and 46.9%, respectively. Significant variation in litter and cake nutrient content was observed and can largely be attributed to ambient temperature differences. Average litter, cake, and total litter (litter plus cake) production rates were 153.3, 74.8, and 228.2 g of dry litter material per kg of live broiler weight (g/kg) per flock, respectively. Significant variation in litter production rates among flocks was also observed. Cumulative litter, cake, and total litter production rates after 18 flocks were 170.3, 78.7, and 249.0 g/kg, respectively. The data produced from this research can be used by broiler producers to estimate broiler litter and cake production and the nutrient content of these materials.

Effects of top-dressing recycled broiler litter on litter production, litter characteristics, and nitrogen mass balance

Top-dressing is a method of broiler litter management in which a thin layer of new, clean litter material is spread over the top of previously used litter prior to placement of a new flock. This fresh layer of bedding material increases the absorptive capacity of the litter and decreases litter caking. Although this practice has been widely used in the poultry industry for many years, no research has been conducted to quantify the effects the practice has on broiler performance, litter production rates, and nutrient content, or the ability of broiler litter to retain manure N and prevent volatilization. An experiment was conducted to quantify these parameters under simulated commercial conditions in a research facility. Nine consecutive flocks of broilers were reared on recycled broiler litter that had previously been used for 9 flocks. Control pens received no litter treatment whereas top-dressed pens received a thin layer of new rice hulls (1 to 2 cm) before the placement of each flock. Nitrogen loss was calculated using the mass balance method. Average broiler performance was not different between the top-dressed and control pens. Top-dressing of litter significantly (P < 0.05) reduced caked litter production compared with control pens in 6 of 9 flocks. However, average total litter production over all 9 flocks was not different between the 2 litter management strategies. In all flocks, litter N content was significantly reduced in top-dressed pens compared with control pens. As a result, litter C:N ratios were significantly higher for pens with top-dressed litter. Differences in N loss between the treatments were not consistent. Average N loss for all flocks was 10.61 and 11.92 g of N/kg of marketed broiler for control and top-dressed pens, respectively, or 20.1 and 22.5% of N inputs, respectively. Based on this experiment, top-dressing of recycled broiler litter would not be recommended as a strategy to reduce the volatilization of N from broiler rearing facilities and, in fact, may actually increase N loss.

Resazurin assay of radiation response in cultured cells

We describe use of resazurin reduction for measurement of cell response to irradiation as a simple and non-destructive assay that complements the conventional colony forming assay and can readily be applied to both adherent and non-adherent cell cultures. The resazurin method yields data comparable with the colony forming assay as well as to assay of DNA synthesis (BrdU incorporation), giving an OER (oxygen enhancement ratio) of 2.5 at 60% isoeffect level versus 3.1 for the colony forming assay. Intraday and interday precisions for the resazurin assay were 4.1% and 5.2%, respectively.

Impact of Dietary Supplemental Methionine Sources on Sensory Measurement of Odor-Related Compounds in Broiler Excreta

An experiment was conducted to detect differences in odor characteristics of broiler excreta due to utilization of different supplementary Met sources by a trained human descriptive aroma attribute sensory panel. The 5 treatment groups were no supplemental Met (control group), sodium methioninate aqueous solution, dry Met hydroxy analogue, liquid Met hydroxy analogue, and DL-Met. Two trials were conducted consisting of 5 treatment groups with 3 replications of 13 randomly distributed straight run broiler chicks per pen reared in battery cages. Starter and grower diets were formulated to contain 0.5 and 0.38% Met activity, respectively (except control group, 0.35% Met activity). Excreta were collected for 24 h in litter pans lined with aluminum foil at wk 4, 5, and 6 and analyzed by a trained sensory panel (7 people). Each panelist was given 25 g of manure heated at 27 degrees C for 5 min for sensory analysis. The 13 odor attributes used to determine differences in broiler excreta by the trained sensory panel were ammonia, dirty socks, wet poultry, fermented rotten fruit, hay, musty wet, sharp, sour, urinous, rotten eggs, irritating, pungent, and nauseating. Panelist marked intensities for each attribute ranging from 0 = none and 15 = extremely intense. Each panelist was given 2 replications of each treatment group in a random order each week (total of 10 samples per wk). All data were evaluated by ANOVA using the general linear model procedure of SAS software. No significant differences were observed in BW, feed consumption, or feed conversion among the treatments. The attributes of ammonia, wet poultry, rotten fruit, musty wet, sharp, and pungent differed (P < 0.05) across treatment groups. These findings demonstrate that supplemental Met sources significantly influence odor production in broiler excreta.

The impact of methionine source on poultry fecal matter odor volatiles

To determine the impact of Met source on volatile compounds of broiler excreta, 2 trials were conducted using straight-run broiler chicks that were randomly distributed in battery cages with 3 replicate pens of 16 birds each. The treatment groups were 1) dry Met hydroxy analogue (52% Met activity), 2) sodium methioninate aqueous solution (45.9% Met activity), 3) liquid Met hydroxy analogue (88% Met activity), 4) DL-Met, (98% Met activity), and 5) no supplemental Met. All starter diets were formulated to contain 3,135 kcal of ME/kg, 23% crude protein, and 0.8% total Met activity and otherwise met NRC nutrient requirements. Diets were fed ad libitum from d 1 to termination of the study (5 to 6 wk). Feed consumption and feed conversion were measured daily, and all birds were weighed weekly. There were no significant differences in BW, feed consumption, or feed conversion among the treatments in either trial. All excreta were collected in litter pans daily lined with aluminum foil. Litter pans for each pen were individually transferred to a separate room for weekly odor volatile analysis. An electronic nose was used to capture 3 to 4 air samples from various locations for each pan of broiler excreta resulting in a total of 10 air samples from each treatment group. All data taken from the electronic nose were evaluated using analysis of variance. Results indicated that there were significant differences in volatiles in the broiler excreta for all treatment groups. These data indicate that different Met sources may result in the production of different odor-related compounds in broiler excreta.

The Impact of Supplemental Dietary Methionine Sources on Volatile Compound Concentrations in Broiler Excreta

The impact of different Met sources on broiler fecal odor volatiles was determined by evaluating the types of sulfur compounds produced in broiler excreta. Two experiments were conducted using straight-run broiler chicks randomly distributed in battery cages, with 3 replicate pens of 16 birds each. The treatment groups were 1) dry Met hydroxy analogue (dry MetHA), 2) sodium methioninate aqueous solution (NaMet), 3) liquid Met hydroxy analogue (Liq MetHA), 4) D,L- Met, and 5) no supplemental Met (control group). The Met activities of each Met source were 52, 45.9, 88, and 98%, respectively. All diets were formulated to contain either 0.8% (experiment 1) total Met activity or 0.5% Met activity in the starter and 0.38% Met activity in the grower (experiment 2) (except the control group, 0.35% Met activity), but otherwise met NRC nutrient requirements (NRC, 1994). Diets were fed ad libitum from d 1 to 6 wk of age. There were no significant differences in BW among the treatments. All excreta were collected in litter pans lined with aluminum foil. In experiment 1, at wk 6, broiler excreta were collected for a 24-h period, and 4.5 g of broiler excreta from each treatment group was collected into 15-mL headspace vials. Samples were analyzed by gas chromatography/mass spectrometry (GC/MS). The volatile sulfur compounds that were identified and quantified in the broiler excreta were H2S, carbonyl sulfide (COS), methyl mercaptan (CH3SH), dimethyl disulfide (CH3SSCH3), and dimethyl trisulfide (CH3SSSCH3). The NaMet treatment group had significantly higher concentrations of H2S, COS, and CH3SSCH3 compared with all other treatment groups. The Liq MetHA group had significantly lower concentrations of H2S, COS, CH3SH, and CH3SSCH3 compared with the other treatment groups. The dry MetHA group significantly had the highest concentration of CH4SH. The D,L-Met treatment group had the significantly highest concentration of CH3SSSCH3 and the lowest concentration of H2S. The control group had the significantly lowest concentrations of CH3SH, CH3SSCH3, and CH3SSSCH3 compared with the other treatment groups. In experiment 2, at wk 6, an electronic nose was used to evaluate 15 air samples per treatment group. In addition, 15 air samples (containing 6 to 8 L of air in a Tedlar bag, 3 samples per treatment group) were collected for odor evaluation by a sensory panel. Electronic nose sensor data revealed that volatile compounds in broiler excreta from the control group were significantly different from the other 4 treatment groups. Evaluation of the air samples by a sensory panel determined that there was a statistically significant difference in odor threshold detection between the control group and the other treatment groups. The dilutions to threshold of control group, NaMet, dry MetHA, Liq MetHA, and D,L-Met were 350, 492, 568, 496, and 526 odor units, respectively. These findings demonstrate that dietary Met sources significantly influenced odorous volatile concentrations in broiler excreta.

Evaluation of a method of ultraviolet light sanitation of broiler hatching eggs

Sanitation of hatching eggs is an important area of research due to the need for an effective, economical, and safe method of egg sanitation. Improved hatching egg sanitation is an important part of an overall pathogen reduction program within integrated poultry operations. This must be accomplished without disturbing the cuticle of the egg, which can decrease hatchability. The ability of ultraviolet (UV) light to kill bacteria on eggshell surfaces has been well documented. To accomplish the task of treating the eggs in a method that could be commercially implemented, a cabinet was constructed in which ultraviolet lamps were placed. A conveyor system was used to carry a plastic hatching egg flat containing 42 eggs through the cabinet for a period of 3 or 4 min. Ultraviolet intensities within the cabinet reached a maximum of 14 mW/cm2. Experiments were conducted to test the impact of UV light (254 nm) exposure of hatching eggs on aerobic plate counts (APC), inoculated Salmonella typhimurium and inoculated Escherchia coli. In the first three experiments, seven eggs were sampled from a flat passed through the UV chamber. Ultraviolet-treated eggs compared to untreated eggs had APC reductions of 1.3 log, S. typhimurium had a 4 log reduction, and E. coli had a 4 to 5 log reduction. Laboratory trials were also conducted to test the effects of UV irradiation on the cuticle of the egg and hatchability. No significant differences for eggshell conductance or hatchability were found between UV-treated and control eggs. From these trials, it can be concluded that UV irradiation of hatching eggs in a prototype irradiation cabinet can effectively reduce aerobic and pathogenic bacteria on eggshell surfaces without affecting eggshell conductance or hatchability.

Reduction of eggshell aerobic plate counts by ultraviolet irradiation

The effects of 254 nm ultraviolet light (UV) radiation on aerobic plate count (APC) of egg shells were investigated. In the first experiment, eggs were exposed to UV treatment (7.35 mW/cm2) for 0, 15, 30, and 60 s. Three eggs from each treatment were aseptically collected and placed into sterile plastic bags containing 50 mL of sterile phosphate-buffered solution. Serial dilutions of the phosphate-buffered solution were plated on aerobic plate count agar and incubated at 37 C for 48 h. Exposure of eggshells to 30 and 60 s UV significantly reduced aerobic plate counts compared to untreated eggs. Exposure to 60 s of UV resulted in a 2 to 3 log10 cfu/egg APC reduction and reduced counts below detectable levels. In the second experiment, UV lights were placed in a chamber equipped with a commercial-style egg conveyor. A UV treatment of 7.5 mW/cm2 and time intervals of 0, 12, 36, and 48 s were used. Three eggs were placed consecutively on the conveyor and passed through the chamber. The center egg was selected for APC evaluation. Sample size, dilution, plating, and incubation procedures were used as described for the first experiment. A significant 1 to 2 log10 reduction in colony-forming units per egg between the eggs treated 48 s to the untreated eggs was detected. The results of these studies show that UV light treatment at high intensities and low time intervals has the potential to reduce aerobic plate counts of eggshells.

Comparison of eggshell surface microbial populations for in-line and off-line commercial egg processing facilities

The objective of this project was to evaluate the aerobic plate counts (APC) of eggshells at in-line and off-line egg processing facilities at selected sites, throughout the processing procedure. Samples were collected from four sites in the processing plant and five time periods during the daily processing shift. Site 1 was from the conveyor system before the eggs passed through the washing system. Site 2 was after detergent wash but before sanitizer application. Site 3 was immediately after sanitizer treatment. Site 4 was immediately before packaging. Samples were collected from the sites at five equally spaced intervals beginning 15 min after the processing shift began and ending 15 min before the processing shift ended. At each sampling time, eggs were aseptically collected from each site and placed into sterile plastic bags containing 50 mL of PBS that was serially diluted immediately. The dilutions were plated on APC agar within 8 h of collection and were incubated at 37 C for 48 h. APC counts of in-line and off-line eggs were compared within time periods across sites. As the processing shift progressed, off-line APC counts were significantly higher than in-line counts at Site 1. At Site 2, off-line APC counts were significantly higher than in-line counts for Periods 2 through 5. At Site 3, off-line APC counts were significantly higher than in-line counts for Periods 2 through 5. Site 4 off-line counts were significantly higher than in-line counts at all time periods.

Characterization of alkaline hydroxide-preserved whole poultry as a dry byproduct meal

Studies were conducted to examine the chemical preservation of whole broiler carcasses by using aqueous alkaline hydroxide solutions. Conversion of the preserved carcasses and solutions into an acceptable poultry byproduct meal was examined. Carcasses and alkaline solutions at a 1:1 ratio were blended and freeze-dried to produce a high fat whole poultry byproduct meal. The dry meal was analyzed for nutrient composition, true metabolizable energy, and amino acid content. Viable bacteria were not recovered after inoculation of the experimental meal with Salmonella enteritidis. The meal was incorporated at 5 and 10% of chick starter diets. Chicks found the meal-containing diets acceptable. Feed consumption, water consumption, BW, and mortality were not significantly different among the dietary treatments in either of the two feeding trials. Necropsy samples revealed no pathological or histological differences attributable to consumption of the alkaline poultry byproduct and blood serum evaluation found no variation in blood chemistry. Alkaline treatment of whole broiler carcasses was an effective preservation method and acceptable as a dry poultry byproduct meal.

Egg marketing in national supermarkets: specialty eggs--part 2

Large eggs promoted as having one or more features beyond conventional white or brown shell eggs (specialty eggs) were evaluated for quality and price in a national retail study. Subtypes of specialty eggs included: nutritionally altered eggs, organic eggs, fertile eggs, eggs from welfare-managed hens, or hens fed all-vegetable diets. Extension Poultry Specialists in California (CA), Connecticut, Illinois, North Carolina, Pennsylvania and Texas conducted a survey of egg quality and price and compared 246 dozen specialty eggs with 390 dozen conventional white shell eggs during the summer of 1996. Age of the eggs based on carton dating indicated specialty eggs were older (16.5 d) than white eggs (11.7 d). Average egg weights for specialty compared to white were 60.2 and 59.6 g, respectively. Interior egg quality evaluations including albumen height, Haugh units (HU), and percentage HU <55, indicated white eggs were superior (5.0 mm, 67.5, and 10.6%, respectively) compared to specialty eggs (4.7 mm, 63.8, and 16.3%). Although the percentage of cracked eggs was similar between specialty and white eggs (5.4 and 5.7%), the percentage of leakers was threefold higher for the specialty eggs (1.0 vs. 0.3%). Egg price was substantially higher for the specialty eggs, averaging $2.18/dozen with a range from 0.88 to $4.38, compared to white eggs, averaging $1.23/dozen and ranging from 0.39 to $2.35.

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.

Egg marketing in national supermarkets: egg quality--part 1

Two surveys were conducted to determine the quality of eggs offered to consumers in large supermarkets in various regions of the US. The first survey was conducted in California (CA) in 1994 and included 38 samples of large (L) and extra large (XL) white eggs in 15 markets. Individual eggs were weighed, candled, and broken out for Haugh unit (HU) determination. Regional differences in age of eggs, the number of eggs below 55 HU, and the percentage of cracked eggs were observed. The second survey was conducted in California (CA), Illinois (IL), Pennsylvania (PA), Texas (TX), North Carolina (NC), and New England (NE). This study included brown and white eggs and samples from 115 stores in 38 cities. Significant age, egg weight, HU, and cracked egg differences were observed between states. Brown and white eggs were different relative to age and HU, but egg weights and cracked eggs were statistically the same. The two surveys, 1994 and 1996, within CA demonstrated very similar measurements when L-white eggs were compared.

Response of foodborne Salmonella spp. marker strains inoculated on egg shell surfaces to disinfectants in a commercial egg washer

The objective of this study was to determine the effectiveness of an iodine based disinfectant (IBD, Iocide, Biomedical Development Corporation, San Antonio, TX) on Salmonella enteritidis and S. typhimurium inoculated on egg shell surfaces under simulated industry egg processing conditions with a commercial egg washer used as the sanitizer delivery system. Re-circulated egg washer water containing 1.40-2.85 g/l total dissolved solids was obtained from a commercial egg processing. Sanitizing treatments consisted of distilled deionized water (DDW), IBD, and chlorine (CL; 200 ppm). All treatments (DDW, IBD and CL) significantly (p < 0.05) decreased Salmonella spp. populations on the shell compared to dry (no spray) egg controls. However, efficacy of egg sanitizers appeared to be dependent on the level of total dissolved solids in the egg wash water.

Chemical preservation of whole broiler carcasses utilizing alkaline hydroxides

The chemical preservation of whole broiler carcasses utilizing aqueous alkaline hydroxide solutions was examined as an alternative method of mortality management. Conversion of the preserved carcasses and solutions into an acceptable poultry by-product meal was examined. This research identified the basic parameters for effective preservative solutions that simultaneously hydrolyzed feathers and preserved the carcass. Euthanized, fully feathered, mature broilers were placed in potassium hydroxide (0.5 to 2.0 M) and sodium hydroxide (0.12 to 2.0 M) solutions for 5 and 10 d. Effectiveness was evaluated by visible feather degradation and carcass solubilization, odor production, inhibition of microbial growth, and solids content of the alkaline solutions. Sodium hydroxide at 1.9 and 2.0 M diffused throughout the carcass and produced adequate preservation without apparent putrefaction through 10 d. Aerobic bacteria were not recovered from sodium hydroxide solutions, carcass skin, or intestine samples at the 1.9 M concentration. Treatments of 2.0 M potassium hydroxide and a mixture of 1.5 M potassium hydroxide with 0.5 M sodium hydroxide produced the highest degree of carcass liquification at 10 d without visible putrefaction. Sodium hydroxide solution (2.0 M):carcass weight ratios ranging from 1:1 through 4:1 (wt:wt) were effective in preserving individual carcasses for more than 60 d without putrefaction.

The impact of pH on nitrogen retention in laboratory analysis of broiler litter

Land application of broiler litter must fully regard agronomic and environmental issues, which requires increased precision in all aspects of land application of poultry litter. Previous researchers note that litter experiences significant nitrogen loss due to ammonia volatilization during the drying process. Others note that pH of poultry houses and litter significantly affects nitrogen loss due to ammonia volatilization. Recent work shows that acidifying agents effectively reduce ammonia generation in poultry production facilities. This concept is used in this study to adjust the pH of broiler litter samples prior to drying to reduce nitrogen loss during the drying process. Samples from four sources were used. Untreated litter was compared to litter treated with Al2(SO4)3, (10:1 wet weight basis) either in small (10 g) or large (100 g batches). Both Al2(SO4)3 treatment methods significantly lowered litter sample pH. No significant differences were observed in litter moisture analysis values. Regardless of source, litter treated in small batches had significantly higher nitrogen values than untreated litter. Large batches of treated litter did not consistently have higher nitrogen values than untreated litter. Treatment of litter samples with Al2(SO4)3 prior to drying resulted in more accurate quantification of nitrogen in litter, which can ultimately result in more accurate utilization of litter in agronomic applications.

Dietary methionine intake effects on egg component yield, composition, functionality, and texture profile analysis

The influence of supplemental Met levels ranging from 413 to 556 mg per hen per d (mg/HD) on liquid egg component yield, composition, and functionality was examined in mature layers (29 wk of age). Egg weight, component yield, solids, and CP content of albumen and yolk were determined. Texture profile analysis, feed ingredient functionality testing, and PAGE were conducted to determine whether increased egg total solids and CP content resulted in altered egg component functionality or electrophoretic protein banding pattern. Albumen component yield increased significantly on a mass basis at 507 and 556 mg/HD Met compared to 413 mg/HD Met. Yolk mass yield was significantly increased at 556 mg/HD Met compared to 413 mg/HD Met. Consumption above 413 mg/HD Met resulted in significantly increased albumen total solids and protein. Yolk solids were not significantly different; however, yolk CP was significantly increased at 507 and 556 mg/HD Met compared to 413 mg/HD Met. Albumen and yolk functionality at 413 and 507 g/HD Met were not significantly different in relation to cake volume or height. Emulsion separation at 120 min was significantly increased for 556 mg/HD Met compared to 413 and 507 g/HD Met. There were no significant differences in hardness or springiness of albumen and yolk gel plugs and electrophoretic protein banding patterns. Increased understanding of the influence of Met on liquid egg yield and composition may provide the egg producer with an effective and advantageous management technique for shell egg production specifically managed to maximize liquid egg product.

Shell Egg Sanitation: UV Radiation and Egg Rotation to Effectively Reduce Populations of Aerobes, Yeasts, and Molds

The intensity of UV radiation (254 nm) and egg rotation were examined for their effect on aerobic microorganisms, yeast, and mold on egg shell surfaces. Aerobic microorganisms, yeast, and mold populations were significantly reduced by UV treatments at 1,720 μW/cm². Eggs rotated at 1 revolution per min under 1,720 μW/cm² of UV light had significantly reduced populations of aerobic microorganisms. Higher intensity (4,350 μW/cm²) with egg rotation also significantly decreased aerobic microorganism populations. Eggs treated with rotation and 15 min of 4,350 μW/cm² of UV radiation had significantly lower populations of aerobic microorganisms than eggs without rotation. Eggs rotated and exposed to 15 min of 4,350 μW/cm² of UV were compared to eggs dipped in 200 ppm chlorine-treated water solution for 1 min, exposed to 3 × formaldehyde fumigation for 20 min, sprayed with commercial sanitizer (Bioguard®) for 3 min, and eggs receiving no treatment. Eggs treated with UV radiation had significantly higher populations of aerobic microorganisms than eggs from other treatments but significantly lower bacterial populations than the control group. Mold and yeast populations of UV-treated eggs were significantly lower than the untreated eggs. The results of this study indicate that UV radiation can significantly reduce aerobic microorganisms, yeast and molds on egg shell surfaces.

The effect of L-lysine intake on egg component yield and composition in laying hens

Currently, 24% of the total U.S. egg supply is consumed as liquid egg product (LEP). In addition to egg weight and size, the commercial value of LEP is a function of percentage solids. The influence of L-Lys on LEP, the texture profile analysis of heat formed albumen and yolk gel plugs, and yolk emulsion separations was examined in two experiments. In Experiment 1, 108 layer hens (42 wk of age) were fed three sorghum-soybean diets with Lys levels ranging from 677 to 1,613 mg per hen per d (mg/HD). In Experiment 2, 108 layer hens (23 wk of age) were fed four sorghum diets with Lys levels ranging from 638 to 1,165 mg/HD. In Experiment 1, Lys intake of 1,613 compared to 677 mg/HD significantly increased albumen weight, solids, and protein and egg weight. There were no significant differences in egg production, feed consumption, or yolk weight, protein, and solids. In Experiment 2, Lys intake of 1,165 mg/HD resulted in significantly lower feed consumption, nutrient intake, and egg production. Lysine intake of 1,062 compared to 638 mg/HD resulted in significantly greater albumen solids, protein, and hardness, and egg production. Lysine intake of 828 compared to 638 mg/HD resulted in significant increases in yolk weight, protein, hardness, and emulsion separations. Lysine intakes of 1,062 mg/HD resulted in most yolk parameters returning to levels observed at 638 mg/HD. There were no significant differences in egg weight or yolk solids. This increased understanding of the influence of L-Lys on LEP parameters offers economic benefit to liquid egg producers.

Effect of dietary methionine intake on egg component yield and composition

The effects of methionine intake on liquid egg component yield and composition were examined in two laying hen experiments using diets supplemented with differing levels of methionine. In Experiment 1, a high methionine intake level of 512 was compared to 326 mg per hen-day (HD). The 512 mg/HD intake significantly increased egg weight, component mass, and total solids in both albumen and yolk. Experiment 2 examined methionine intakes of 328, 354, 392, and 423 mg/ HD. There were no significant differences in egg weight, component yield, or egg production among the treatments. Albumen solids from the 423 mg/HD intake level were significantly elevated when compared to 328 and 354 mg/HD. A methionine consumption of 354 mg/HD resulted in significantly lower yolk solids than 328, 392, and 423 mg/HD. Methionine intakes of 392 and 423 mg/HD did result in significantly increased crude protein content of albumen and yolk compared to 328 and 354 mg/HD methionine. Experiment 1 found elevated dietary methionine increased egg size, component mass, and solids content of albumen and yolk. Experiment 2 methionine intake significantly increased crude protein of albumen and yolk without changes in egg size or component yield. These results indicate a methionine intake range that will later liquid component composition while egg size remains unchanged.

Effects of cage population on the productive performance of layers

Two commercial layer strains (3,456 hens total) were used to examine the effects of bird population on productive performance. Four cage population sizes (6, 8, 12, and 24 birds per cage) were compared. All cages were 35.7 cm deep and varied in width (61.2, 81.6, 122.4, and 244.8 cm). Floor space per bird was 364.1 cm2 and feeder space per bird was 10.2 cm in each cage configuration. Egg production and egg quality were measured from 20 to 72 wk of age. Strain differences were detected in hen-day egg production, egg mass, feed consumption, cracked egg percentage, Grade A eggs, Grade B eggs, peewee eggs, and large egg yield. There were no interactions between strain and cage population size. Cage population had no influence on hen-day egg production, mortality, feed conversion, egg size (peewee, small, medium, large, extra large), egg mass, lost eggs (by meat or blood spots), and percentage Grade B eggs. Percentage Grade A eggs, cracked egg percentage, and feed consumption were significantly influenced by cage population size. Hens housed at eight birds per cage had a greater percentage of Grade A eggs and a lower percentage of cracked eggs than those at other populations. Feed consumption was significantly greater for hens housed at 12 and 24 birds per cage compared with those at 6 and 8 birds per cage, respectively.

Influences of age at final beak trim on the productive performance of commercial layers

Two commercial egg-type strains were beak-trimmed at 10, 10 and 63, or 10 and 84 d. There were no interactions between strain and beak trimming treatment. Pullet feed consumption was significantly reduced within the 14-d period following beak trimming at 63 or 84 d. Total pullet feed consumption (1 to 126 d) was significantly lower among birds trimmed twice than among those trimmed only at 10 d. At 126 d, body weight of pullets trimmed at 10 and 84 d or 10 and 63 d was significantly less than that of those trimmed only at 10 d. Pullet mortality was not significantly influenced by beak trimming treatments. No significant effects of beak trimming treatments on layer mortality, egg production, egg weight, egg mass, feed conversion, or egg quality were detected. Layer feed consumption was significantly greater among birds beak trimmed at 10 d than among those trimmed at 10 and 84 d. Most of the effects associated with beak trimming treatments can be attributed to the influence that beak trimming had on feed consumption.

Salmonella contamination in commercial eggs and an egg production facility

Egg samples were collected from various stages of an egg processing operation and from the attached production facility. Salmonella was isolated from 72.0% of all samples collected from the laying house environment. Recovery of Salmonella from flush water, ventilation fan, egg belt, and egg collector samples were (positive samples/total samples collected): 2/2, 4/4, 16/22, and 14/22, respectively. Salmonella was found on 7 of the 90 eggshells sampled before processing and 1 of 90 eggshells sampled after processing, but Salmonella was not found in the 180 eggs analyzed for internal contamination following processing. The one eggshell found positive for Salmonella following processing was detected when the pH of wash water samples was lowest (10.19). The 60 isolates from production facilities included the following Salmonella serotypes: S. agona, S. typhimurium, S. infantis, S. derby, S. heidelberg, S. california, S. montevideo, S. mbandaka, and untypable. The 22 isolates obtained from eggshells prior to processing were serotyped as S. heidelberg and S. montevideo. All five isolates obtained from eggshells after processing were serotyped as S. heidelberg. These data suggest that although the shells of about 1% of commercial eggs are contaminated with Salmonella, contamination of the internal contents of eggs with Salmonella is a rare event.

Intermediate filament antigens of 60 and 65 kDa in the nuclear matrix of plants: their detection and localization

Although the presence of a matrix in plant nuclei has been reported, major questions remain about its structural and biochemical features. We have used an intermediate filament antibody of broad specificity to explore whether Daucus carota (carrot) nuclei and nuclear matrices contain intermediate filament/lamin antigens and, if so, where specifically they are localized. SDS-PAGE and Western blotting revealed two bands, at 60 and 65 kDa, that were highly immunoreactive with the intermediate filament antibody (IFA) of Pruss et al. (1981, Cell 27, 419-428). This pattern was observed consistently, not only with carrot cell-free nuclei and nuclear matrices, but also with nuclear preparations from Vicia faba (broad bean) and Pisum sativum (pea). Immunofluorescence studies with whole carrot nuclei localized the IFA antigens to the nucleoplasm and disclosed no accentuated peripheral labeling. Agarose-embedded nuclear matrices showed not only fluorescence throughout the nucleoplasm but also heavy labeling surrounding the nucleoli and suggestions of peripheral labeling. At the ultrastructural level, immunogold results from pre- and postembedment treatments supported the conclusion that IFA antigens occur throughout the nucleoplasm, with possibly a slight concentration at the periphery. These combined results provide substantial evidence that plant nuclei and their matrices possess at least two major intermediate filament antigens with molecular weights characteristic of animal lamins. Whether or not these antigens represent plant lamins, their nonperipheral localization hints at significant differences among the eukaryotic kingdoms in nuclear organization.

Influence of age at final beak trimming on pullet and layer performance

Effects of final beak trimming on pullet and layer productivity were examined with three strains of commercial layers. All pullets were precision-trimmed at 7 days with final beak trimming at either 63, 84, or 105 days. Transient depressions of pullet body weight and feed consumption were noted in the periods immediately following beak trimming. Pullet mortality from 7 to 18 wk of age and 18-wk body weight were not significantly affected by beak trimming treatments. Strain effects were noted in rate of feed consumption following beak trimming. Age at 50% production was significantly later among birds trimmed at 63 days than among those trimmed at 84 or 105 days. Feed consumption, egg production, and mortality (140 to 441 days) were significantly lower among birds trimmed at 63 days than among those trimmed at 84 or 105 days. Egg quality and size were not influenced by beak trimming treatments.

Effects of pullet-stocking density on performance of laying hens

Effects of cage-stocking density during the rearing period on three commercial strains housed in open and closed rearing and laying houses were examined in two experiments. Stocking densities in Experiment 1 were 311, 259, and 239 cm2 per bird and in Experiment 2 were 311, 259, and 222 cm2 per bird. In the rearing period, greater stocking densities significantly reduced feed intake and 18-wk body weight and increased age at 50% production. In the second experiment, mortality to 20 wk was higher among birds reared at 222 cm2 per bird compared to the less dense treatments. In the laying phase of the experiments, there were no differences among the treatments in number of eggs per bird housed, layer mortality or kilograms of feed consumed per kilograms of egg produced. Final (499 days) body weight of hens reared at 222 cm2 per bird was significantly less than that of those in the other treatment groups. Egg weight of birds reared at 22 cm2 per bird was significantly greater than that of birds reared at 311 cm2 per bird in Experiment 2. Calculated incomes over feed and chick costs were not different among the treatments in either experiment. A less rapid decline in egg production was noted among birds reared at the highest stocking density over the time of the experiment.

Lithocholic acid in human-blood serum

Lithocholic acid was present in the serum of three patients with, jaundice and, in smaller amounts, in two healthy adults. This bile acid occurs naturally in human feces but induces cirrhosis of the liver when fed to a wide variety of experimental animals. The finding of lithocholic acid in blood is of interest because of its possible role in injuring human liver.