Research Note: Evaluation of manganese hydroxychloride in 45-wk-old white leghorn layers using yolk and shell manganese content.

The objective of the current study was to evaluate increasing levels of manganese hydroxychloride (MHC) in 45-wk-old white leghorn laying hens, using yolk and shell manganese (Mn) content as a potential marker for Mn concentration. A total of 80, 45-wk-old white leghorns were assigned to 6 dietary treatments, each consisting of 14 individually caged laying hens, with the exception of the reference diet containing 10 individually caged laying hens. The experiment consisted of a reference diet that contained 70 ppm of supplemental inorganic Mn in the form of Mn oxide and 5 experimental treatments each containing 0, 15, 30, 60, and 90 ppm supplemental MHC. Experimental birds were subjected to a 21 D depletion phase in which no supplemental Mn was included in the diet; however, during this time reference fed birds were fed the control diet (70 ppm Mn). After the 21 D depletion phase, the depleted birds were fed experimental diets for a 35 D evaluation period. Yolk and shell Mn content were analyzed at the end of the depletion phase and during the experimental phase on day 5, 10, 15, 25, and 35. During the experimental phase, Mn was replenished in the yolk and shell in all experimental treatments containing supplemental Mn; however, dose and time impacted the rate of replenishment. The yolk tended to be more sensitive to variations in Mn level as increases in Mn inclusion significantly (P < 0.05) increased concentration. These data demonstrate the ability to deplete and replenish Mn, and the use of egg yolk Mn concentration as measurement for determining changes in dietary Mn. At the conclusion of the experiment at 35 D, 60 ppm of Mn hydroxychloride seemed to be adequate in replenishing Mn to the level of the reference.

Advanced Oxidation Process sanitization of hatching eggs reduces Salmonella in broiler chicks.

The microbial quality of eggs entering the hatchery is an important critical control point for biosecurity, pathogen reduction, and food safety programs in poultry production. Developing interventions to reduce Salmonella contamination of eggs is important to improving the microbial food safety of poultry and poultry products. The hydrogen peroxide (H2O2) and ultraviolet light (UV) Advanced Oxidation Process (AOP) has been previously demonstrated to be effective in reducing Salmonella on the surface of experimentally contaminated eggs. The objective of this study was to evaluate the effect of treating eggs with an egg-sanitizing apparatus using the H2O2/UV AOP on Salmonella contamination during incubation, hatching, and in broiler chicks during grow-out. Experimentally contaminated eggs were treated using the automated H2O2/UV AOP egg sanitizer and incubated for 21 d. AOP sanitization reduced Salmonella up to 7 log10 cfu egg-1 (P < 0.05) from the surface of experimentally contaminated eggs and reduced the number of Salmonella positive eggs by up to 75% (P < 0.05) when treated 1 h post-inoculation. AOP treatment also reduced the number of Salmonella-positive eggs during incubation. Additionally, Salmonella was recovered from more chicks hatched from untreated eggs than from eggs treated using the H2O2/UV AOP egg sanitizer (P < 0.05) through 14 d posthatch. These data suggest reduction of Salmonella contamination on the surface of eggs using the H2O2/UV AOP egg sanitizer prior to incubation may reduce the gastrointestinal colonization of chicks by Salmonella.

Disinfection of eggshells using ultraviolet light and hydrogen peroxide independently and in combination.

Poor hatchability can occur due to eggshell bacterial contamination, which can be decreased by UV light or H(2)O(2) alone. However, antimicrobial effects of these 2 treatments combined, as well as optimum length of UV exposure, are not known. Therefore, the objectives of this study were to determine the optimum length of UV exposure for maximum bacterial reduction and to determine if a greater bacterial reduction would occur using a combination of UV and H(2)O(2) compared with either treatment alone. The first experiment was conducted to determine the optimum length of UV exposure by exposing eggs to 4, 8, 16, and 32 min of UV. Three experiments were also conducted to determine what concentration of H(2)O(2) in combination with UV exposure would yield maximum bacterial reduction. For experiment 2, treatments consisted of a control and UV alone as well as 0, 1, 2, and 3% H(2)O(2) alone and in combination with UV for 8 min. In experiment 3, treatments consisted of a control, UV alone, 3% H(2)O(2) alone, as well as 0, 0.5, 1, 1.5, 2, 2.5, and 3% H(2)O(2) in combination with UV for 8 min. Experiment 4 used 10 treatments including a control and 1.5, 2, and 2.5% H(2)O(2) at UV exposure times of 2, 4, and 8 min for each H(2)O(2) concentration. Results indicated that every control eggshell contained bacteria, resulting in an average bacterial count of 4 log cfu/egg. Exposure to UV alone for 8 min yielded significant bacterial reductions without excessive egg heating. When administered independently, H(2)O(2) and UV each reduced eggshell bacterial counts by 2 log cfu/egg. The combination of 1.5% H(2)O(2) and UV for 8 min reduced bacterial counts by a maximum of 3 log cfu/egg, with only 35% of the eggs positive for bacteria. Because bacterial contamination was further reduced by using a combination of UV and H(2)O(2), it is possible that hatchability and chick quality of breeder eggs might be improved by such treatments.

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.

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.

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.

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 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.

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.

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.