Brief Summary of Minutes of Annual Meeting

I. Poultry House Environment. Thermal. NE conducted a study to determine the mechanism(s) by which heat stress reduces egg production in laying hens and, further, to determine differences exist between strains of hens selected for slightly different production characteristics. Hens from three Hy-Line® strains, Brown, W36, and W98, were housed individually under 16L:8D and randomly assigned to one of three thermal treatments: thermoneutral (TN) 22C, 50% RH; acute heat stress (AHS, 24h) 36C, 50% RH; or chronic heat stress (CHS, 2wk) 36C, 50% RH. Follicles were removed and granulosa cells (GC) were isolated, incubated with one or a combination of hormones, stained for the steroidogenic enzyme 3²-HSD using nitroblue tetrazolium, and expressed as % active cells. The hormone incubation treatments were LH, FSH, LH+FSH, PRL, LH+PRL, FSH+PRL, FSH+LH+PRL, and the control cells were incubated without addition of hormones. In TN cells, enzyme activity, as % active cells, increased in response to LH; the increase was greater with LH+FSH. With FSH alone and PRL alone, % activity was suppressed. When LH was added to PRL, enzyme activity improved over PRL alone and LH+FSH added to PRL increased activity further; however, both treatments failed to bring activity to the level of activity in TN cells. When examined by strain, responses to hormone treatments under AHS followed responses at TN, with indications that strain differences may exist. These differences became marked under CHS, with W98 consistently above the other two strains in response of enzyme activity to hormone treatments. It is possible that this confers at least in part the advantage to this strain of hen with regard to its ability to sustain egg production during heat stress and that it in turn is the result of its ability to sustain acid base balance, as earlier studies have shown. Other conclusions from this study are that at least some level of LH is necessary for GC to sustain activity of 3²-HSD during HS but that FSH is necessary in combination with LH to achieve maximum activity. Aerial. IL determined that laying hen manure samples did not accurately reflect ammonia emissions from the source from which it was collected. Expression of ammonia emissions from samples can be different from the source, which is probably related to variety of factors such as: mass, environmentally exposed surface area, time of exposure, and mixing or disruption of the profile of the manure source. Units used to express ammonia emission rate from manure need to be related to environmental impact rather than just in arbitrary values and units. IA, in collaboration with KY and PA, measured and published the results of ammonia emissions from commercial layer houses, as affected by housing style (high-rise vs. manure-belt), manure management schemes (annual storage in the high-rise houses, daily removal or every 3-4 day removal from the manure-belt houses), and type of ration (standard vs. reduced crude protein diet). The findings also have been disseminated to the egg industry and allied industries through local, regional and national extension/education workshops. The data contribute to the much needed baseline emission information for animal feeding operations under U.S. production conditions. IA, in collaboration with KY, PA and IN, examined the suitability of using carbon dioxide (CO2) balance to indirectly determine building ventilation rate of manure-belt houses by comparing the indirectly determined ventilation rate with the directly measured ventilation rate. The results revealed the uncertainties of the indirect method associated with different integration time intervals. Ventilation rate is one of the two key factors for determining pollutant emissions from confinement buildings. Yet it is often a formidable task to accurately and economically quantify building ventilation rate. Alternative, cost-effective means to determine ventilation rate is thus of great importance to air emission studies. IA conducted a series of lab-scale studies to evaluate the efficacies of various pre- and post-excretion emission mitigation strategies for laying hens. The strategies include dietary manipulation, physical configuration of manure storage stacks, and topical application of mineral or chemical agents (i.e., zeolite, alum, etc.) at various dosages. Progress results were reported through conference or workshop papers/proceedings (ASABE, AWMA, Iowa Egg Industry Symposium). Practically feasible means to mitigate air emissions from animal feeding operations will ultimately help the animal production industry improve its environmental soundness and continue its ability to provide safe and affordable food supply to the population. IA, in collaboration with CA, developed a framework for process-based ammonia emission models for dairy, swine, and poultry. The model provides a comprehensive evaluation of production practices on ammonia emission. Once developed and validated, it is anticipated to be a powerful tool for estimating emission inventories and predict impacts of various best management practices on reduction of ammonia emissions. PA, along with KY and IA conducted research on ammonia emissions from eight commercial poultry houses in PA with some houses demonstrating emission-reduction strategies. This project is in its final stages and is part of a USDA IFAS funded project. Ammonia level was determined using an electrochemical sensor system developed by the project investigators. Ventilation rate was estimated by monitoring building static pressure difference and runtime of the ventilation fans whose airflow rates were determined in situ with a portable anemometer array. Similar emissions were seen from similar poultry housing situations across the states. More frequent manure removal resulted in lower house emissions (manure storage emissions would be impacted). Project website contains more information: www.bae.uky.edu/IFAFS. This project has resulted in the most comprehensive ammonia emissions baseline data available at this time in the USA for broiler chicken and laying hen facilities. Emissions from several types of poultry houses can be used on-farm for comparison among emissions abatement strategies. The published work presents effective strategy for on-farm data collection with accurate data obtained in rugged poultry/livestock housing environments. This multi-state, multi-disciplinary project has developed and published a comprehensive database of ammonia emissions. Three peer-reviewed journal articles are in print, with another four in-press. Visual Responses. CA did work with commercial broiler chickens and commented that they are often reared in near-continuous light, which has been reported to be associated with a higher incidence of leg problems and ascites. It has also been suggested, although with little evidence, that sleep patterns are disrupted in near-continuous lighting. We examined the effect of three lighting schedules on the behavior, weight gain, and leg condition of broilers. Broilers (194 Ross 308 and 96 Ross x Cobb) were housed in environmental chambers. During the first week, all treatments received a 23L: 1D regime (100 lux and 1 lux during the photophase and scotophase, respectively. On day 7, each chamber was assigned a lighting regime of either 23L: 1D, 20L: 4D, or 16L: 8D for weeks 2-5 (20 lux photophase and 1 lux scotophase). At day 35, all chambers were put on a 23L: 1D regime to stimulate compensatory growth. Behavior was observed continuously 2 days per week, and the broilers were gait scored using a 0-5 system at 42 days of age. Broilers showed few differences in their overall pattern of behavior regardless of photoperiod. However, birds given a longer dark period of 8 hours did sleep more than broilers given either 4 or 6 hours of darkness. There was no effect on production of providing a longer dark period. In contrast to previous studies, photoperiod length had no effect on gait score. However, a long light period was associated with more total external lesions and more leg bruising. These results suggest that a longer dark period can be beneficial in increasing sleep, with no negative effects on production, although further work in larger-scale trials is necessary to confirm this. Auditory Responses. CT determined that egg production and quality of life of poultry can be affected by noise levels in their environments. They may also demonstrate extreme behaviors in high transient noise situations. Vocalizations of chickens of various ages, breeds, sex and rearing conditions and ambient noise levels are being recorded for classification using a Hidden Markhov Model and for acoustic stress analysis. Results will be used to determine stress levels of chickens under various rearing conditions. Spatial Responses. IA studied feeding behavior of laying hens as affected by stocking density of 348, 387, 426, or 465 cm2 (54, 60, 66, or 72 in2) per hen. Results revealed no significant difference among the stocking densities under thermoneutral conditions with regard to daily feed intake (97-101 g/hen, p=0.37), hen-hours spent feeding per cage (17.8-24.0 hen-hours/day, p=0.32), average daily feeding time per hen (3.0-4.0 h/day, p=0.32), number of meals ingested per day per cage (117-181 meals/day, p=0.18), meal size (1.6-2.6 g/meal-hen, p=0.09), average meal duration (174-258 sec/meal, p=0.40), ingestion rate (0.47-0.77 g/min-hen, p=0.06), and number of hens feeding per meal (1.9-2.0 hens/meal, p=0.72). MD did work in space analysis and determined that increments in stocking density have been argued to restrict movement and use of space in broilers due to social factors (associated with concurrent increments in group size (GS)) and/or a reduction of space availability. The aim of this experiment was first, to quantify the effect of increasing stocking density on movement and use of space in broilers and second, to isolate the contribution of social factors from the impact of the reduction of space available. Artificial chicken-sized models, added to pens with 30 and 60 broilers, simulated the spatial availability of 90 birds while theoretically controlling for social factors associated with increasing GS. Model size was increased bi-weekly to mimic broiler growth. Group size/stocking density treatments (GSD) were as follows: 90/0, 60/0, 60/30, 30/0, 30/60 (# birds/# models). In the absence of social factors broilers in the 30/60, 60/30, and 90/0 GSD were predicted to show similar use of space patterns. Walking, steps taken, and path linearity (# of changes in direction of movement) were recorded. Core areas were calculated using spatial data obtained from focal birds. Data were analyzed by Mixed Model ANOVA with age as the repeated measure. Walking frequency and duration and number of steps taken were similar across all GSD (P>0.05). GSD groups differed in the level of path linearity (P<0.05), with trajectories being more linear in the 90/0, 60/0, and 30/0 GSD. GSD with equal density (90/0, 60/30, 30/60) had core areas of similar size (P>0.05), all of them surprisingly larger than those of 30/0 and 60/0 GSD (Fig. 1). Aggressive interactions were affected by GSD (P<0.05) with lowest levels of aggression observed in the 30/0 and 90/0 GSD. These results suggest that at relative low ranges of density, walking behavior and steps taken are not affected by density. In contrast, the analysis of core areas suggest that birds at higher densities use a wider range of space, possibly as result of the presence of other birds in their path of movement. In this study social factors associated with increments in density do not appear to have a relevant impact on the patterns of movement and use of space. MI conducted two experiments were conducted during a growout of male and female white pheasants to evaluate brooding space needed the first 6 wk and appropriate phase feeding strategies in the growing-finishing stages of growth. One-day-old chicks were placed into brooder pens with stocking rates of 150, 200 or 250 chicks/pen. Individual body weight and feed conversions for each pen were measured at 3 and 6 wk of age and litter moisture was measured at 3 wk. Birds were separated by gender at 6 wk and fed a common grower diet to 12 wk of age. At 12 wk, approximately half of the birds of each gender were fed either the grower diet or a finisher diet containing about 5 percentage units less crude protein than the grower diet. Body weight and feed conversion were measured on a pen basis at 12 wk for all birds, 17 wk for cockerels and 20 wk for hens. At market age, a sample of birds from each pen was selected to measure carcass yield and proximate analysis. There were no effects on body weight, coefficient of variation of body weight within pen, or feed conversion in the brooding period. High stocking density (350 chicks/pen) increased litter moisture at 3 wk. There were no dietary treatment effects on growth performance or carcass traits for either gender in the growing-finishing phases. The result showed that dietary protein could be reduced by 23% in a finisher diet fed after 12 wk of age to white pheasants. Social Stress. MD conducted a study examining the social needs of chickens. Social groups of chickens are unable to form stable hierarchies are common in poultry production. The long term effects of these environments on the birds behavior are unclear. To study this, we simulated the social conditions of production by exposing two lines, HGPS and LGPS, of male White Leghorns selected for high vs. low group productivity and survivability, to social stress involving recurrent regroupings with two-day intervals between 6 and 14.5 weeks of age. Agonistic interactions were observed in seven 15-bird groups/line, of which 4 belonged to social stress and 3 to control treatment, on the 2nd day after each regrouping. The treatment period was divided into three sub-periods of equal length. During the first period, HGPS birds showed both intensive (e.g. attacks) and mild (e.g. threats) agonistic acts more than LGPSs, the effect of line decreasing thereafter. In the second period, intensive agonistic activity was greater in HGPS controls than stressed HGPSs, a treatment effect lacking among LGPSs. In the last period, no line or treatment effects were present. After the regroupings, 16 birds/treatment and line were tested after four-day training in a long arena where 4 cages provided with strangers (except during training) were protruding in the corridor with a food source at the end of it. In this test, no line or treatment effects were found for a latency to reach the food source past the strangers, while in both lines the birds underwent the stress treatment passed by the strangers more frequently than the controls. Our results suggest that in the long term, birds living in unstable social environments may adopt alternative behavioral strategies/styles in order to avoid high energy consuming agonistic behavior. It also seems possible that the capacity of a bird to adapt to an unstable environment may be influenced by genetic selection. II. Physiological and Behavioral Responses to Management Practice Beak Trimming. MN conducted research on the practice of beak-trimming in turkeys and examined welfare concerns and cannabalism in cooperation with H. Xin and R. Cook (IA), I. Estevez (MD), and M. Beck (NE). Male turkey poults were either not trimmed or had the upper beak trimmed after hatching by electric arc, infrared, or hot blade methods. Poults were fed either mash or crumbles/pellets to 18 wks of age. Performance, feed intake, behavior, and histology of beaks was determined. Feed form had the greatest effect on performance with improved body weight and feed conversion for turkeys fed pelleted feed of 5.2 and 9.6%, respectively (P<.05). Higher mortality (P<.06) was observed for poults that were trimmed by hot blade in comparison to the control for the first 6 wks of the trial. An interaction of trim and feed form was noted for feed disappearance where feed disappearance was lower for the arc and infrared trimmed poults in comparison to the control or hot blade trimmed birds during 0-6 wks. Removal or culling of birds due to aggressive picking damage was greater for the untrimmed and hot blade trimmed turkeys in comparison to those trimmed by arc or infrared. Beak trimming had minimal effects on performance with the greatest control of aggression in turkeys beak trimmed by electric arc or infrared methods. Bill Trimming. CA conducted a study to determine the effects of a commercial bill-trimming method, cutting without cautery, on the behavior and bill morphopathology of ducks. Muscovy ducks were housed in 12 pens each containing 16 ducks (8 males and 8 females). Half of the ducks were trimmed (TRIM) using scissors at 20 days post-hatch, while the rest were sham-trimmed (NOTRIM). The behavior of all ducks was recorded until 12 weeks of age, at which time the bills of the male focal ducks were collected, sectioned, stained and subjected to histological analysis. TRIM showed transient decreases in bill-related behaviors, and increased resting, post-trim. There was also a transient check in weight gain. Behavioral and weight differences between TRIM and NOTRIM were no longer evident after the first week post-trim. The TRIM bills were scarred and lacked vascularization, but there were no neuromas. It is likely that the extensive scarring prevented nerve regrowth into the bill. These results are consistent with this bill-trimming method causing acute, but not chronic, pain in Muscovy ducks. Induced Molt. IL conducted a study where nonfeed withdrawal molt diets were restricted fed in a molting program. This study indicated that feeding a soybean hulls-corn diet ad libitum or restricted during the 28-day molt period is an effective non-feed removal molt program. In addition, restricted feeding of a wheat midds-corn diet had no negative effect on postmolt performance. Hens fed a wheat midds-corn molt diet ad libitum had lower egg production than any other treatment, presumably due to the higher ME content of this diet. Nutrition. MS conducted work on increasing amino acid density early in life and has shown to increase subsequent growth performance and breast meat yield. However, reducing nutrient density as birds reach market weight will decrease nitrogen content of excreta and may reduce ammonia production as well as allow for growth comparable to a higher CP regimen. This study examined growth performance, plasma metabolites, nitrogen excretion, and ammonia production of male broilers during a 35 d production period. Two-hundred and forty Ross x Ross 708 male broilers were randomly assigned into Petersime batteries having raised wire floors (5 birds/cage) at one d of age. Dietary treatments consisted of four feeding regimens formulated to moderate (M) or high (H) amino acid density based on an ideal amino acid pattern. Diets were fed from 1 to 7, 8 to 19, and 20 to 35 d. Feeding regimen treatments were 1) HHH; 2) HHM; 3) HMM; 4) MMM. Each treatment was represented by 12 replicate pens. At d 26, blood was collected from one bird/pen for the determination of plasma total protein and uric acid concentrations. A 48 h total excreta collection period (33 to 35 d) was conducted to assess nitrogen excretion and ammonia production. Broilers fed the HHH regimen had improved (P£0.03) cumulative BW gain and feed conversion, but feed consumption and mortality were unaffected. Feeding the H amino acid density diet until 19 d of age improved (P£0.02) BW gain. Plasma total protein and uric acid were similar among the treatments. From 33 to 35 d, increasing amino acid density increased (P£0.04) nitrogen excretion and ammonia production. We conclude that reducing amino acid density during the final phase of growth decreased nitrogen excretion and ammonia production but cumulative feed conversion was compromised. MS also found that providing broilers diets formulated to a high amino acid density early in development improves subsequent growth performance and breast meat yield. However, feeding broilers diets formulated to a high amino acid density from 5 to 8 wk of age may not be economically justified. This study examined growth responses and meat yield of broilers provided diets varying in amino acid density from 36 to 59 d of age. Two identical trials were conducted. In each trial, sixteen hundred and sixty-four Ross x Ross 708 chicks were randomly distributed into 32 floor pens (26 males and 26 females; 0.08 m2/bird) at one-d of age. All birds were fed common  high amino acid density diets to 35 d of age. Broilers were provided diets characterized as being high (H), moderate (M), or low (L) in amino acid density from 36 to 47 and 48 to 59 d of age. The diets were formulated to contain: H (19.8%, CP, 0.83%, TSAA, and 1.05%, Lys), M (18.2%, CP, 0.80%, TSAA, and 0.95%, Lys) , and L (16.7%, CP, 0.75%, TSAA, and 0.85%, Lys) from 36 to 47 d and H (18.0%, CP, 0.78%, TSAA, and 1.00%, Lys), M (17.3%, CP, 0.75%, TSAA, and 0.91%, Lys) , and L (16.0%, CP, 0.70%, TSAA, and 0.82%, Lys) from 48 to 59 d. Dietary treatments were HHHH, HHHM, HHHL, HHMM, HHML, and HHLL from 36 to 59 d of age. Feeding the HHHH schedule improved (Pd.05) feed conversion by 3, 3, 4, 4, and 7 points compared with the HHHM, HHMM, HHHL, HHML, and HHLL, respectively. Dietary amino acid density did not affect growth rate, feed consumption, and the incidence of mortality. Decreasing amino acid density to HHLL feeding schedule increased (Pd0.05) abdominal fat yield compared with HHHH and HHHM dietary schedules and reduced (Pd0.05) total breast meat yield compared with HHHH, HHHM, HHMM, and HHML dietary schedules, respectively. As amino density decreased to the HHHM, HHMM, and HHML feeding schedules, breast meat yield of broilers was similar to birds fed the HHHH feeding schedule. Total breast meat yield was increased (Pd0.05) by 0.4, 0.4, 0.6, and 0.7% points as amino acid density was increased from HHLL to HHML, HHMM, HHHM, and HHHH feeding schedules, respectively. These results indicate that feeding low amino acid density diets to broilers from 2.0 to 3.9 kg adversely affects feed conversion and total white meat yield. MN in cooperation with K. Roberson and J. Kalbfleisch (MI), the feeding value of distillers dried grains with solubles (DDGS) was examined by determination of energy content and available phosphorus. A grow-finish trial was conducted with commercial tom turkeys to confirm the appropriate energy value of DDGs to use in diet formulation. Turkeys were fed diets varying in level of DDGs (10 or 20% DDGs) and formulated using different levels of MEn (E) assigned to the DDGs during 6 to 19 wks of age. The ME assignments were (kcal/kg): previously determined TMEn in young growing turkeys of 2980; previously determined AMEn with young turkey poults of 2760; and, the NRC (1994) book value of 2480. The basal diet was composed of primarily corn, soybean meal, poultry byproduct meal and .05% supplemental thr. Diets were formulated on a digestible amino acid basis. A control diet with no DDGs was included. The higher inclusion level of 20% depressed body weight in comparison to the control (P < .01) at 11 (7.95 vs. 7.85 kg), 14 (11.99 vs. 11.80 kg), and 19 wks of age (17. 46 vs. 17.11 kg) while performance was similar for the control and 10% DDGs diet. The depression with a 20% inclusion level is in contrast to our previous data that showed that a level of 20% gave similar performance to that of the control diet series. A reduction in diet protein level through the use of supplemental thr may have negatively affected the performance response. Cumulative 6-19 wk feed efficiency (f/g) was poorer for turkeys fed 20% DDGs diets in comparison to 10% DDGs (2.552 vs. 2.522) but neither dietary treatment was different from the control (2.53). Diets varying in E did not affect turkey body weight. When the TMEn value was used in formulation, cumulative 6-19 wk f/g was poorer as compared to the NRC value (2.56 vs. 2.53) (P<.05). Determination of energy by TMEn resulted in an overestimation of the energy value of the DDGs when using feed efficiency as the response criteria. While there was no difference in response for the NRC or AMEn energy value, use of the lower NRC energy value could have a large effect on diet cost. Bioavailability of phosphorus was determined to be at least equivalent to dicalcium phosphate and was usually in excess of 100%. Data Analyses and Decision Analyses. MS has done work on neural networks which offers a alternative to regression analysis for biological growth modeling. There is very little research that has been conducted to model animal growth using artificial neural networks. Twenty-five male chicks (Ross x Ross 308) were raised in an environmental chamber. Body weights were determined on a daily basis. Feed and water were provided ad libitum. The birds were fed a starter ration (23% protein 3200 kcal ME) from 0 to 21 d and a grower ration (20% protein and 3200 kcal ME) from 22 to 70 d. Dead and female birds were not included in the study. Average body weights of the remaining 18 birds were used as the data points for the growth curve to be modeled. Training data consisted of every other day weights starting with the first day. Validation data consisted of the remaining body weights. Comparison was made between the modeling by the Gompertz nonlinear regression equation and neural network modeling. Neural network models were developed with the Neuroshell Predictor. Developed neural networks were evaluated in an Excel spreadsheet using the Neuroshell runtime server program. The predictor model is based on one of two models called neural and genetic. The training procedure is based on the premise that the accuracy and precision of the model can be adjusted by inclusion or exclusion of the nodes in the hidden layer. The genetic approach was also evaluated. Quantitative examination of the fit of the predictive models was made using error measurement indices commonly used to evaluate forecasting models. Accuracy of the models were determined by Mean Absolute Deviation, Mean Absolute Percentage Error, Mean Square Error and Bias. The Gompertz equation was fit for the data. Forecasting error measurements based on the difference between the model and the observed values. For the training data, the lowest MSE, MAD, MAPE and bias were noted for the neural developed neural network. For the validation data, the lowest MSE, MAD, and MAPE were with the genetic algorithm developed neural network. Lowest bias was for the neural developed neural network. As measured by bias, the Gompertz equation under estimated the values while the neural and genetic developed neural networks produced little or no overestimation of the observed body weight responses. Past studies attempted to interpret the biological significance of the estimates of the parameters of an equation, it may be more practical to ignore the relevance of parameter estimates and focus on the ability to predict responses. MS also found that monitoring growth is important in assessing flock performance during growout. Weighing birds within a flock can be labor intensive; therefore, a non-contact method of weighing is desirable. This objective of this study was to determine if projected area of the bird is a viable method to estimate BW. One hundred Ross x Ross 708 chicks were placed into four environmental chambers at 1 d of age. Thirty five male birds were labeled with leg bands and weighed at 1, 3, 5, and 7 wks of age. A digital still camera was suspended on two tripods 86 cm above the floor and used to acquire images of each bird directly after weighing. The birds were individually placed on a matte-black backdrop for photography, and no attempts to correct posture or position were made. The height of the camera remained constant throughout the growing cycle to maintain the same image scale such that total image area would remain constant, and projected area could be directly compared. Images were edited to isolate the two-dimensional projection of the bird and stored as 8-bit binary images; projected pixel area was determined via histogram analysis. Regression analysis was performed on the BW as well as various combination of linear, logarithmic, and power transformations. Correlations between BW and projected area were observed (R2 e 0.92), regardless of posture or orientation and transform type. A natural log transform of both BW and projected area provided the best fit (R2 = 0.98), yielding the following relationship: BW = e[-18.109 + 1.388×ln(area)]. Eight birds from a separate ongoing trial were weighed and photographed for use as a validation set and the predicted BW was compared to actual BW using a paired t-test. Mean predicted BW was not significantly different from actual BW (P = 0.36). Results of this research suggest that estimating broiler weight through digital imaging may provide a non-contact method for assessing performance during growout.