Food, energy, and the environment.

During the 2009 annual meeting of the Poultry Science Association, a symposium entitled "Global Views of New Agriculture: Food, Energy, and the Environment" was held that focused on several major issues affecting agriculture. Issues included future funding for basic agricultural research, sustainability, bioenergy, and their effects on global food markets. In many ways, a subtitle for the symposium could have been "Agriculture-Why What We Do Matters." It matters because of the fiscal and physical realities the planet will face in the coming decades relative to human population growth and the increasing demands to feed a hungry world. The challenges are daunting and the technologies to address them will require us to reevaluate the structure and policies we have established relative to agricultural research. In this case, change is all the more difficult because the traditional model of agricultural research has been so successful. One only needs to note the remarkable increases in productivity of the past half century of commodities such as corn and soybeans or feed efficiencies among broilers, laying hens, and turkeys to recognize the significant advancements that have been achieved. However, these historic gains have frequently required increased inputs, most notably fossil fuels. Food production in the future will likely be confronted with concerns involving energy, water, climate change, and the threat of agroterrorism. For example, we will need to develop crops that are more drought-resistant and more tolerant to a wider range of salinities as access to fresh water becomes more problematic. Animal agriculture will also need to adapt to diets composed of atypical feedstuffs. Whether future generations will inherit a world described by Paul Roberts in his books The End of Oil and The End of Food will be in part determined by the research model we adopt in the near term.

Production of chick germline chimeras from fluorescence-activated cell-sorted gonocytes.

Modification of the chicken germline has been difficult, because it has been challenging to fractionate sufficient numbers of primordial germ cells for manipulation and implantation into developing embryos. A technique to enrich cell suspensions for primordial germ cells, using fluorescence-activated cell sorting (FACS), has recently been developed. The objective of the current study was to demonstrate that the FACS-enriched early embryonic gonocytes could fully participate in development of the germline. Therefore, cells were disassociated from stage 27 gonads, incubated with mouse anti-stage-specific embryonic antigen-1, which was detected with goat-antimouse IgM-fluorescein isothiocyanate, and the fluorescently labeled cells were sorted from the unlabeled cells using FACS. The isolated gonocyte population was injected into the blastoderm of unincubated stage X embryos, the germinal crescent of 3-d embryos, and into the circulation of stage 17 embryos that were pretreated with busulfan. Barred Plymouth Rock gonocytes were implanted exclusively into recipient White Leghorn embryos, and White Leghorn gonocytes were implanted exclusively into Barred Plymouth Rock recipient embryos. Embryos were cultured until hatch, and male putative chimeras were reared to sexual maturity. Germline chimerism was evaluated by observing feather color of the progeny. All injection methods resulted in germline chimeras demonstrating that FACS-sorted gonocytes can fully participate in development. Moreover, it was demonstrated that gonocytes isolated from stage 27 embryonic gonads can be introduced into embryos at an earlier stage of development, and the introduced gonocytes can fully participate in germline development.

Isolation of chicken primordial germ cells using fluorescence-activated cell sorting.

Presently, it is difficult to undertake germ line modification of the chicken with primordial germ cells (PGC) because it has been difficult to efficiently fractionate the PGC from the total somatic cell population. The objective of this study was to develop a method that allows isolation of an enriched population of viable PGC from embryonic blood and embryonic gonadal tissue. Blood was harvested from early chick embryos (stages 13 to 15), and cells were liberated from the gonads of stage 27 chick embryos. Subsequently, viable PGC were labeled with anti-stage-specific embryonic antigen-1 (SSEA-1), which was detected with goat-anti-mouse IgM-fluorescein isothiocyanate. Fluorescently labeled cells were sorted from the unlabeled cells using fluorescence-activated cell sorting (FACS), and the identities of the PGC were confirmed using periodic acid-Schiff (PAS) staining or anti-embryonic mouse antigen-1 (EMA-1) staining followed by microscopic evaluation. Finally, PGC were sorted from somatic cells of sex-identified embryos. Less than 0.1% of the blood cell population was collected as SSEA-1-positive cells. Similarly, approximately 2% of the gonadal cell population were collected as SSEA-1-positive cells. Therefore, fewer (-1,000 to 9,000) PGC were recovered from each isolate. Placing the sorted SSEA-1-positive cells on a glass slide from a microcentrifuge tube resulted in a recovery rate of 53 to 73% relative to the number detected by FACS. Furthermore, the proportions of sorted cells that stained with PAS or anti-EMA-1 following sorting were 92+/-4% PAS positive and 94+/-1% anti-EMA-1 positive. Finally, the sorted SSEA-1-positive cells were maintained in vitro to demonstrate their viability after sorting. It was demonstrated that it is possible to label blood and gonadal chicken PGC with SSEA-1 and subsequently to sort viable SSEA-1-positive PGC from somatic cells.

The virtual revolution: implications for academe.

The global expansion and acceptance of the Internet as been unprecedented. The emergence of the potential for distance learning (DL) has altered the way in which faculty, university administrators, and for-profit corporations view the educational process. In 1998, nearly 80% of public 4-yr institutions offered some DL courses. However, DL courses in agriculture and natural resources represented less than 1% of the total enrollment. Like any technology that ushers in a new era of change, DL has attracted enthusiastic supporters and detractors. Few view DL with neutrality. It is this divergence of opinion that has fueled the debate over the academic value of DL. A valid evaluation of the educational benefits or deficiencies of DL may require additional long-term studies. For some academic traditionalists, DL is viewed as the fusion of education and commerce and borders on the repugnant. Others embrace DL not only because it may provide a source of much needed revenue, but also because it allows for the low-cost delivery of information to a nontraditional pool of students. Well-funded, private, for-profit organizations and universities have developed a number of DL models. Some hybrid DL models exist in which public institutions have created independent for-profit corporations to develop and distribute their web-based courses. The question is not if DL will be a part of the educational landscape; it surely will. The challenge is to define the role DL can most effectively fulfill.

Improvement of poult performance following Bordetella avium challenge by administration of a novel oxy-halogen formulation.

The ability of a novel oxy-halogen formulation (OHF) to alter the development of bordetellosis (turkey coryza) in large white turkey poults was assessed. Bordetella avium (BA)-infected (1-day-of-age) and noninfected control poults received 0, 0.008%, or 0.016% of an OHF continuously in the drinking water. At 4, 7, 10, 14, and 17 days of age, reisolation of BA from infected poults was attempted. Infected poults receiving 0.016% OHF exhibited significantly lower cumulative BA reisolation rates (90%) when compared with infected poults receiving 0 (96.7%) or 0.008% OHF (100%). At 7, 14, and 17 days of age, infected poults in the OHF-treated groups were significantly heavier than those BA-challenged poults receiving control water. Feed utilization was significantly improved from hatch to 7 days of age in BA-infected poults receiving OHF when compared with infected poults receiving control water. Clinical symptoms were severe only in untreated, infected poults and were mild or absent in all others. Damage to the tracheal epithelium, as measured by scanning electron microscopy, paralleled the clinical signs. Tracheal epithelial damage was virtually eliminated by OHF administration in infected poults. These results suggest that OHF treatment ameliorates many of the symptoms frequently associated with bordetellosis in young turkeys.

Providing credentials to our graduates.

Provision of meaningful professional credentials to Poultry Science graduates requires the sharing of expertise among a number of departments. Increased access to specialized poultry courses will assist in assuring that all graduates have excellent technical credentials. Greater access could be brought about through distance learning materials developed on a regional basis. Professional credentials will protect the marketability of our graduates in a changing industry and provide them a starting point for continued professional development. All departments, large and small, can claim an essential niche in the instruction and examination process. Another benefit is that to maintain their professional status, graduates would periodically participate in seminars and short courses and be encouraged to maintain active memberships in associations such as the Poultry Science Association.

Educational opportunities and challenges in poultry science: impact of resource allocation and industry needs.

Because the number of Poultry Science departments in the U.S. has declined dramatically, and because scientist years and research funding for poultry, relative to other commodities, have also declined, a survey of poultry meat companies was conducted. Objectives of the survey were: to evaluate corporate concern over the status of Poultry Science departments, to categorize hiring patterns, to determine expectations for prerequisite skills of graduates, and to ascertain attitudes toward hiring of Associate-degreed students (A.S.). A two-page survey was distributed to corporate Vice Presidents or Directors of Human Resources of the 17 largest broiler and 10 largest turkey companies. When asked to gauge the difficulty they encountered in locating adequate numbers of Poultry Science graduates, 83% noted at least some difficulty. All respondents indicated concern over the loss of poultry programs in the U.S. and 44% noted "extreme" concern. There appears to be little resistance to hiring 2-yr A.S. degree graduates in Poultry Science. The relative scarcity of these programs is demonstrated by the fact that only one-third of the respondents had ever hired A.S. degree graduates. However, greater than 80% of the firms indicated they would hire these students. Finally, communication and business skills were more highly rated by human resources management than technical ability in Poultry Science. Given these results, academic programs must: develop curricula that reflect market-place expectations, enhance the efficiency of resource utilization, embrace new technologies that provide novel methods for information delivery, and reassess cooperative linkages among industrial and governmental organizations.

A harness and computer system to facilitate automated body temperature data collection in heat-stressed broilers.

An easy-to-use, low-cost system was developed that permitted nearly continuous, automated core body temperature (Tc) readings on 7-wk-old male broiler chickens via direct computer linkage to thermistor probes held in place by a specially designed harness. Elevated Tc was noted in heat stress studies following the replacement of expelled temperature probes in some hyperthermic birds. To demonstrate the usefulness of the data collection system described herein, three treatments with three to four birds per treatment were used to examine this observation. Birds were designated as handled only (HAN), handled to remove and replace the temperature probe (RPL), or left as nonhandled controls (CON). Treatments had no effect on subsequent Tc in experiments when the thermoregulatory capacity of the birds was not challenged. However, when the birds were sufficiently challenged, Tc of HAN and RPL birds increased within 4 min of the initiation of handling and remained above baseline for up to 45 min. The Tc of CON birds in that trial also increased, but to a smaller degree, within 5 min and remained above baseline for up to 20 min. This study indicates that Tc of hyperthermic birds can be superelevated by simulated manual placement of cloacal temperature probes and that fixed probes connected to an automated data monitoring and collection system is a relatively simple way to avoid this problem.

Relative bioavailability of L-ascorbyl-2-polyphosphate in broiler chickens.

Broiler chick diets and drinking water were supplemented with two sources of vitamin C: crystalline L-ascorbic acid (AsA) or L-ascorbyl-2-polyphosphate (APP) to provide 0, 25, 50, 100, 200, 400, 800, 1,600, and 3,200 ppm (mg/kg) AsA. The bioavailability of APP relative to AsA, as estimated by the change in plasma AsA concentration, was evaluated during 24-h periods of supplementation. When provided in the feed, no differences in dietary AsA content were attributed to vitamin source. In contrast, APP administration at 25 and 50 ppm, resulted in higher (P < .001) AsA values in drinking water when compared with AsA supplementation. Plasma AsA values were elevated (P < .05) above baseline when either AsA or APP were supplemented in the feed or water at a level of 400 ppm or greater. Plasma AsA concentrations, following supplementation of the diets, were higher (P < .05) in AsA-treated (800 ppm) chicks when compared with APP-supplemented chicks. During water supplementation, AsA (800 ppm) and APP (3,200 ppm) administration resulted in higher plasma AsA values when compared with their alternate vitamin source. At all other levels of water supplementation, no differences in plasma AsA were associated with vitamin source. The absence of a consistent difference in plasma AsA, relative to vitamin source, suggests that the isolated differences observed may be due to chance. It was concluded that APP was of similar bioavailability to that of AsA, as estimated by the ability to elevate plasma AsA concentrations in broiler chicks.

Influence of a novel oxy-halogen compound on early growth and nitrogen retention of broiler chickens challenged with Salmonella.

The potential of a novel oxy-halogen compound (OHC) to alter early growth and nitrogen retention of broiler chickens challenged with Salmonella was evaluated. Three hundred and twenty female broiler chicks (Arbor Acres x Arbor Acres) were weighed and distributed randomly within a 2 x 4 factorial arrangement of treatments. Main effects examined were the presence or absence of Salmonella typhimurium (ST) inoculation and OHC treatment. At hatching, 80 chicks were placed in electrically heated brooder batteries in each of four identical isolation rooms. Chicks designated to receive 100 microL of an oral inoculum containing 10(5) ST cfu at 3 days of age were in two of the rooms, and uninoculated chicks were raised in the other two rooms. Four replicates of 10 chicks each received drinking water containing either 0, .05, .1, or .5% OHC for each level of ST. Chicks administered .05% OHC exhibited enhanced (P < or = .01) growth at 7 and 14 days of age when compared with control values. A significant OHC by ST interaction was observed at 7 (P < or = .0001) and 14 (P < or = .03) days of age. Feed utilization was improved (P < or = .01) by OHC administration (.05 and .1%) from hatching to 7 days of age. The administration of OHC reduced (P < or = .01) nitrogen excretion and enhanced (P < or = .01) nitrogen retention by chicks at Day 7. Cecal ST log10 counts at 7 days of age for chicks given water containing 0, .05, or .1% OHC were 4.72, 3.93, and 3.74, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of ascorbate on luteinizing hormone stimulated progesterone biosynthesis in chicken granulosa cells in vitro.

1. Utilizing hen granulosa cells from the two largest (F1 and F2) follicles, we have examined the effect of sodium ascorbate (AS) on luteinizing hormone (LH) stimulated progesterone (PR) biosynthesis. 2. In experiment 1, in vitro AS levels as 0.0, 0.2, 0.4 or 0.8 mM were permutated by LH concentrations of 0.0, 1, 10 or 100 ng/ml. 3. Combination of 0.4 or 0.8 mM AS with physiological LH concentrations significantly (P < 0.05) enhanced (up to 28%) PR production. 4. In experiment 2, levels of AS at 0.3 and 0.6 mM significantly increased (up to 29%) LH induced PR synthesis. 5. These findings suggest that AS may be associated with chicken steroidogenesis as has been indicated for mammalian species.

In ovo administration of boron alters bone mineralization of the chicken embryo.

It has been hypothesized that boron (B) is an essential element for animals, especially in bone metabolism. In this study, the influence of in ovo boron administration was assessed in the chicken. At 8 d of embryogenesis, carrier or B (0.1, 0.5, or 1.0 mg) was injected on to the chorioallantoic membrane of fertile eggs. At hatching, body weights were recorded and tissue samples collected. Although boron failed to alter bone mineralization, it decreased (p less than 0.05) dried bone weight, suggesting a reduction in the bone organic matrix. Furthermore, 1 mg boron decreased (p less than 0.05) hatchability and increased (p less than 0.05) the height of the proliferative zone in the growth plate, indicating an unfavorable effect on bone elongation of the developing chick.

Autosomal albinism affects immunocompetence in the chicken.

Immune responsiveness of three neonatal and juvenile phenotypes, determined by the albinotic C locus, was evaluated. The phenotypes included normally pigmented (C+/-), recessive white (c/ca), and completely amelanotic albinos (ca/ca). No differences in: (1) primary agglutinin levels directed against sheep red blood cells (SRBC) or Brucella abortus (BA), or (2) cell-mediated immunity, as estimated by in vivo mitogen stimulation, were associated with the albino phenotype. The significant suppression of secondary SRBC or BA agglutinins observed in albino chicks was limited and of questionable biological significance. Acquisition of passively transferred maternal BA agglutinins was significantly impaired in albino progeny irrespective of dam genotype. No differences in agglutinin levels were associated with dam genotype. In addition, uptake of yolk sac contents was retarded significantly in albino chicks at hatch. These data suggest that an impaired ability to absorb maternal antibody and not the capacity to mount an active immune response contributes to neonatal mortality in albino chicks.

In ovo growth hormone alters growth and adipose tissue development of chickens.

The effect of in ovo administration of ovine growth hormone (oGH) on growth and adipose tissue development of chickens was investigated. Unlike mammalian species, exogenous growth hormone has not been previously shown to increase growth of aves. In trial 1, fertilized eggs were injected with vehicle (.03 M NaHCO3 in .15 M NaCl, pH 8.3), 0.25, 2.5, 25 or 250 micrograms oGH on day 11 of embryogenesis. In trial 2, fertile eggs were injected with vehicle or 250 micrograms oGH. In contrast to previous studies in which GH was administered to growing birds, oGH injected in ovo in the present study increased body weights, skeletal growth and feed efficiencies of male broilers. Growth rate was not altered in females. Adipose cellularity data from both trials indicated that in ovo oGH also altered adipose tissue development of broilers. Seven-week-old male and female broilers treated with oGH during embryogenesis exhibited larger adipocytes with correspondingly less cell per gram of tissue. Additionally, adipocytes from oGH-treated broilers exhibited decreased sensitivity to glucagon, cholera toxin or theophylline-induced lipolysis responsiveness to dcAMP in ovo. Cholera toxin plus theophylline improved the lipolytic response of oGH-treated birds; thus, in broilers injected with oGH cAMP-mediated lipase activation may be reduced by a mechanism of increased phosphodiesterase activity. The results of this study indicate that growth and tissue development of chickens have been altered by mammalian GH in ovo.

Enhanced integumental and ocular amelanosis following the termination of cyclosporine administration.

The Smyth delayed amelanotic line of chickens display symptoms commonly associated with human vitiligo. Administration of the immunosuppressive compound, cyclosporine, significantly delayed the mean age of onset and incidence of integumental pigment losses in this mutant line of vitiliginous chickens. Associated ocular pathology was also less severe in treated chicks. Termination of cyclosporine administration resulted in enhanced integumental and choroidal amelanosis, choroidal inflammation, and chorioretinal damage beyond that observed in nontreated controls. These results suggest that withdrawal of cyclosporine in treatment of this spontaneous autoimmune disease may exacerbate associated symptoms.

Effect of corticosterone on the incidence of amelanosis in Smyth delayed amelanotic line chickens.

The Smyth Delayed Amelanotic (SDA) line chicken exhibits a postnatal loss of pigment in feathers and choroid presumably due to an autoimmune reaction triggered by a basic pigment cell defect. The present study was designed to determine if the incidence and severity of amelanosis would be affected by administration of corticosterone (CS) in feed. The SDA line chickens were given 0, 20, 30, 40, and 50 ppm CS from 4 to 12 weeks of age. Body weight and incidence of amelanosis were determined weekly and immune response to sheep red blood cells was determined at the end of the trials. Body weight and immune response levels were significantly lower in treated groups than in controls (P less than .001), but no significant differences were found between treated groups on measures of amelanosis or immune response. Incidence of amelanosis in controls (60%) was significantly greater than in treated groups: 20 ppm, 14.2%; 30 ppm, 17.9%; 40 ppm, 12.9%; and 50 ppm, 16.7%. Six weeks posttreatment, treated groups were no longer significantly different from controls in terms of the incidence of amelanosis. It is proposed that the reduction in amelanosis during CS treatment is attributable to suppression of antibody response to the pigment cell antigen by the CS.

Influence of C locus alleles on neonatal development in the domestic fowl.

Neonatal development, as influenced by the autosomal albino (ca/ca), recessive white (c/ca), or colored (C+/-) genotype, was investigated. Albino chicks exhibited smaller (P less than or equal to .005) body weights at 3, 6, and 9 days of age. A significant (P less than or equal to .005) reduction in growth rate also occurred in albinos from hatching to 3 days of age. Associated with the suppression of growth was the retention of greater (P less than or equal to .05) amounts of yolk sac contents. Albino chicks exhibited smaller (P less than or equal to .01) bursal weights at hatching and 6 days of age. Plasma glucose and protein levels were depressed (P less than or equal to .005) in albinos at hatching when compared to recessive white or colored chicks. No significant differences in plasma glucose or protein were noted at any other time periods. These data provide evidence for the retardation of neonatal development and a reduction in maternal yolk utilization by the ca/ca embryo. We suggest that there may exist additional physiological functions for melanin/functional tyrosinase that are not directly involved with pigmentation.

Pleiotropisms associated with alleles of the C locus in the domestic fowl.

Pleiotropisms associated with the recessive white (c) and albino (ca) alleles at the C locus of the domestic fowl were investigated. Hatchability of fertile eggs was not significantly different for the colored (C+/c, C+/ca), recessive white (c/ca), and albino (ca/ca) chicks; however, late embryonic mortality was higher in ca/ca embryos P less than or equal to .005). Albinos exhibited shorter down lengths (P less than or equal to .01), higher incidences of subcutaneous hemorrhage and inflammation (P less than or equal to .01) and an increased incidence of yolk sac protrusions (P less than or equal to .01). Suppressed body weights (P less than or equal to .01) were evident at all times, except at hatching, in both male and female albinos reared in batteries. Recessive white females also exhibited smaller body weights than colored chicks at 7 and 8 weeks of age in battery trials (P less than or equal to .01). Significant suppression of body weights occurred in albinos only at 4 weeks of age in trials where floor rearing was used. Mortality in albinos was also significantly higher, particularly under floor rearing conditions (P less than or equal to .01). In addition, both feed consumption and feed utilization were reduced in albinos (P less than or equal to .01). These data suggest that melanin synthesis is an important component in the expression of a number of important physiological traits and that the C locus exerts a previously undefined regulatory influence on such traits.

Influence of supplemental ascorbic acid on broiler performance following exposure to high environmental temperature.

The present study was conducted to determine if dietary ascorbic acid (AA) would improve growth, feed efficiency, and livability of broilers following an acute heating episode. Supplemental AA was provided in the diets at calculated levels of 0, 250, 500, and 1000 ppm, continuously. Females that received 1000 ppm exhibited significantly greater body weights at 2 and 4 weeks of age. No significant effects due to AA supplementation were observed in body weights of males. At 4 weeks of age, chicks were heated on two consecutive days by increasing the ambient temperature (38.3 C at bird level) in the production facility. Heating significantly reduced body weights in males, but not females, at 5 and 7 weeks of age. Feed conversions were increased after heating, but significant effects due to AA were not found. Ascorbic acid did not improve overall livability significantly in either sex, but heat-associated mortality was reduced in supplemented females.

Role of ascorbic acid in chicks exposed to high environmental temperature.

This study was conducted to determine if ascorbic acid (AA) 1) increases resistance to high environmental temperature in young chickens and 2) alters heat-induced changes in several physiological responses. Groups of male chicks received either a standard ration containing 1,000 mg/kg (ppm) of AA or the ration without AA. Chicks were brooded for 3 wk and then maintained at 22 +/- 0.8 degrees C. At 4 wk of age, both AA-supplemented and control chicks were exposed to 30 min of heating (43 +/- 0.1 degrees C and 40 +/- 2% rh) on each of 3 consecutive h in an environmentally controlled chamber. Chicks were challenged with sheep erythrocytes (1 ml, 10(5) cells, iv) 12 h postheating. Heating reduced plasma potassium, body weight gain, relative bursa and spleen weights, and anti-sheep erythrocyte levels. Heating increased cloacal temperature, plasma protein, corticosteroid levels, and mortality. AA ameliorated many of these stress-related responses.