Inactivation of Cryptosporidium parvum oocysts and faecal indicator bacteria in cattle slurry by addition of ammonia

AIMS

To determine inactivation of Cryptosporidium parvum oocysts and reduction of Escherichia coli and enterococci in cattle slurry added aqueous ammonia.

METHODS AND RESULTS

Escherichia coli, enterococci and nonviable C. parvum oocysts (DAPI+PI+) were enumerated every second day for 2 weeks in cattle slurry amended with 60 mmol l^-1 aq. ammonia and compared with untreated slurry at three temperatures. Regardless of temperature, the proportion of nonviable C. parvum oocysts increased significantly faster over time in slurry with added ammonia than raw slurry (P = 0·021) corresponding to 62·0% higher inactivation (P = 0·001) at day 14. Additionally, 91·8% fewer E. coli and 27·3% fewer enterococci were observed in slurry added ammonia at day 14 compared to raw slurry.

CONCLUSION

The addition of aqueous ammonia to raw slurry significantly reduced the viability of C. parvum oocysts and numbers of bacterial indicators. Hence, ammonia is usable at lower pathogen concentrations in slurry before application to agricultural land.

SIGNIFICANCE AND IMPACT OF THE STUDY

Livestock waste is a valuable source of plant nutrients and organic matter, but may contain high concentrations of pathogens like E. coli and Cryptosporidium sp. that can be spread in the environment, and cause disease outbreaks. However, die-off rates of pathogens in organic waste can increase following increasing ammonia concentrations.

Nitrogen and phosphorus release from organic wastes and suitability as bio-based fertilizers in a circular economy

The drive to a more circular economy has created increasing interest in recycling organic wastes as bio-based fertilizers. This study screened 15 different manures, digestates, sludges, composts, industry by-products, and struvites. Nitrogen (N) and phosphorous (P) release was compared following addition to soil. Three waste materials were then 'upgraded' using heating and pressure (105°C at 220 kPa), alkalinization (pH 10), or sonification to modify N and P release properties, and compared in a second soil incubation. Generally, maximum N release was negatively correlated with the CN ratio of the material (r = -0.6). Composted, dried, or raw organic waste materials released less N (mean of 10.8 ± 0.5%, 45.3 ± 7.2%, and 47.4 ± 3.2% of total N added respectively) than digestates, industry-derived organic fertilizer products, and struvites (mean of 58.2 ± 2.8%, 77.7 ± 6.0%, and 100.0 ± 13.1% of total N added respectively). No analyzed chemical property or processing type could explain differences in P release. No single upgrading treatment consistently increased N or P release. However, for one raw biosolid, heating at a low temperature (105°C) with pressure did increase N release as a percentage of total N added to soil from 30% to 43%.

North European comparison of treatment strategy and survival in older patients with resectable gastric cancer: A EURECCA upper gastrointestinal group analysis

BACKGROUND

As older gastric cancer patients are often excluded from randomized clinical trials, the most appropriate treatment strategy for these patients remains unclear. The current study aimed to gain more insight in treatment strategies and relative survival of older patients with resectable gastric cancer across Europe.

METHODS

Population-based cohorts from Belgium, Denmark, The Netherlands, Norway, and Sweden were combined. Patients ≥70 years with resectable gastric cancer (cT1-4a, cN0-2, cM0), diagnosed between 2004 and 2014 were included. Resection rates, administration of chemotherapy (irrespective of surgery), and relative survival within a country according to stage were determined.

RESULTS

Overall, 6698 patients were included. The percentage of operated patients was highest in Belgium and lowest in Sweden for both stage II (74% versus 56%) and stage III disease (57% versus 25%). For stage III, chemotherapy administration was highest in Belgium (44%) and lowest in Sweden (2%). Three year relative survival for stage I, II, and III disease in Belgium was 67.8% (95% CI:62.8-72.6), 41.2% (95% CI:37.3-45.2), 17.8% (95% CI:12.5-24.0), compared with 56.7% (95% CI:51.5-61.7), 31.3% (95% CI:27.6-35.2), 8.2% (95% CI:4.4-13.4) in Sweden. There were no significant differences in treatment strategies of patients with stage I disease.

CONCLUSION

Substantial treatment differences are observed across North European countries for patients with stages II and III resectable gastric cancer aged 70 years or older. In the present comparison, treatment strategies with a higher proportion of patients undergoing surgery seemed to be associated with higher survival rates for patients with stages II or III disease.

International comparison of treatment strategy and survival in metastatic gastric cancer

Background

In the randomized Asian REGATTA trial, no survival benefit was shown for additional gastrectomy over chemotherapy alone in patients with advanced gastric cancer with a single incurable factor, thereby discouraging surgery for these patients. The purpose of this study was to evaluate treatment strategies for patients with metastatic gastric cancer in daily practice in five European countries, along with relative survival in each country.

Methods

Nationwide population‐based data from Belgium, Denmark, the Netherlands, Norway and Sweden were combined. Patients with primary metastatic gastric cancer diagnosed between 2006 and 2014 were included. The proportion of gastric resections performed and the administration of chemotherapy (irrespective of surgery) within each country were determined. Relative survival according to country was calculated.

Results

Overall, 15 057 patients with gastric cancer were included. The proportion of gastric resections varied from 8·1 per cent in the Netherlands and Denmark to 18·3 per cent in Belgium. Administration of chemotherapy was 39·2 per cent in the Netherlands, compared with 63·2 per cent in Belgium. The 6‐month relative survival rate was between 39·0 (95 per cent c.i. 37·8 to 40·2) per cent in the Netherlands and 54·1 (52·1 to 56·9) per cent in Belgium.

Conclusion

There is variation in the use of gastrectomy and chemotherapy in patients with metastatic gastric cancer, and subsequent differences in survival.

Nitrogen mineralisation and greenhouse gas emission from the soil application of sludge from reed bed mineralisation systems

A sludge treatment reed bed system (STRB) is a technology used for dewatering and stabilising sewage sludge via assisted biological mineralisation, which creates a sludge residue suitable for use as fertiliser on agricultural land. We evaluated the effect of sludge residue storage time (stabilisation time) for three STRBs on soil N mineralisation and CO₂ and N₂O emissions in soil. The experiment revealed that the N mineralisation rate and emissions of CO₂ and N₂O decreased as a function of treatment time in the STRBs. Mixed sludge residue (sludge residue subjected to different treatment times) for the three STRBs resulted in N mineralisation rates similar to the sludge residue subjected to a shorter treatment time but lower N₂O emissions similar to the values of the older sludge residue. This finding reveals that combining fresh and more stabilised sludge residue ensures high N availability and reduces N₂O emissions when applied to land.

Changes in treatment and outcome of oesophageal cancer in Denmark between 2004 and 2013

Background

Since 2003, care for patients with oesophageal cancer has been centralized in a few dedicated centres in Denmark. The aim of this study was to assess changes in the treatment and outcome of patients registered in a nationwide database.

Methods

All patients diagnosed with oesophageal cancer or cancer of the gastro-oesophageal junction who underwent oesophagectomy in Denmark between 2004 and 2013, and who were registered in the Danish clinical database of carcinomas in the oesophagus, gastro-oesophageal junction and stomach (DECV database) were included. Quality-of-care indicators, including number of lymph nodes removed, anastomotic leak rate, 30- and 90-day mortality, and 2- and 5-year overall survival, were assessed. To compare quality-of-care indicators over time, the relative risk (RR) was calculated using a multivariable log binomial regression model.

Results

Some 6178 patients were included, of whom 1728 underwent oesophagectomy. The overall number of patients with 15 or more lymph nodes in the resection specimen increased from 38·1 per cent in 2004 to 88·7 per cent in 2013. The anastomotic leak rate decreased from 14·8 to 7·6 per cent (RR 0·66, 95 per cent c.i. 0·43 to 1·01). The 30-day mortality rate decreased from 4·5 to 1·7 per cent (RR 0·51, 0·22 to 1·15) and the 90-day mortality rate from 11·0 to 2·9 per cent (RR 0·46, 0·26 to 0·82). There were no statistically significant changes in 2- or 5-year survival rates over time.

Conclusion

Indicators of quality of care have improved since the centralization of oesophageal cancer treatment in Denmark.

A bridging stent to surgery in patients with esophageal and gastroesophageal junction cancer has a dramatic negative impact on patient survival: A retrospective cohort study through data acquired from a prospectively maintained national database

This study aimed to assess the impact of esophageal stenting on postoperative complications and survival in patients with obstructing esophageal and gastroesophageal junction (GEJ) cancer. All patients treated without neoadjuvant therapy that had an R0-resection performed for esophageal and GEJ cancer between January 2003 and December 2010 were identified from a prospectively maintained database. Data on stenting, postoperative mortality, morbidity, recurrence-free survival, complications, and length of hospital stay were collected. Kaplan-Meier plots for survival and recurrence-free survival curves were constructed for R0 resected patients. Data were compared between the stent and no-stent group by nonparametric tests. Two hundred seventy three consecutive R0 resected patients with esophageal or GEJ cancer were identified. Of these patients, 63 had a stent as a bridge to surgery. The male/female ratio was 2.64 (198/75) with a median age in the stent group (SG) of 65.1 versus 64.3 in the no stent group (NSG). Patients were comparable with respect to gender, age, smoking, TNM-classification, oncological treatment, hospital stay, tumor location, and histology. The median survival in the SG was 11.6 months compared with 21.3 months for patients treated without a bridging stent (P < 0.001). There were no statistically significant differences in 30-day mortality between the two groups, but NSG patients exhibited a significantly better two-year survival (P = 0.017). The median recurrence-free survival was 9.1 months for the SG compared with 15.2 months for the NSG. The use of a stent as a bridging procedure to surgery in patients treated without neaoadjuvant therapy for an esophageal or GEJ cancer that later underwent R0 resection decreased the two year survival and the recurrence-free survival.

Outcome after Transthoracic Resection of Carcinoma of the Oesophagus and Oesophago-Gastric Junction

Aims:

To assess the postoperative morbidity and mortality, length of stay and long-term survival after resection of carcinoma of the oesophagus and gastro-oesophageal junction, after establishment of a new surgical team unit between thoracic and gastroenterologic surgeons.

Methods:

We analysed the prospective collected data of 166 consecutive patients who underwent a transthoracic oesophageal resection between June 1997 and December 2003.

Results:

There were 119 men and 47 women. The median age was 63 years (range 36–81). Fifty-five patients (33 %) had squamous cell carcinoma and 111 (67 %) had adenocarcinoma. Postoperative complications occurred in a total of 60 patients (36 %). Ten patients (6 %) died postoperatively, eight (4.8 %) due to medical and two (1.2 %) due to surgical complications. The median postoperative length of stay was 11 days (range 6–75). The overall 3- and 5- years survival was 35.6 % and 30.6 % respectively. Survival was adversely affected by patient age and tumor stage.

Conclusions:

Concentrating resection for carcinoma of the oesophagus and oesophagogastric junction to a dedicated team of specialists, including both gastrointestinal and thoracic surgeons as well as thoracic-anaesthesiological know-how, results in acceptable complication rates as well as low mortality rates especially due to surgical complications.

Organisation and Early Outcomes of Major Upper Gastrointestinal Cancer Surgery in Denmark 1996–2004

Background:

To assess the relationship between hospital volume and early postoperative outcome the incidence and early outcome of all esophagectomies, pancreaticoduodenectomies and gastric resections in Denmark from 1996 to 2004 was described.

Methods:

The National Patient Registry and discharge information from all hospital departments were analysed for all the operations due to a malignant diagnosis. All information was examined for postoperative length of stay and hospital mortality.

Results:

During the study period 26 departments performed at least one esophageal resection, 13 departments performed at least one Whipple procedure and 37 departments performed at least one gastric resection. Four departments performed more than 20 esophageal resections per year, whereas one department performed more than 20 Whipple procedures and one more than 20 gastric resections per year. The overall mean length of stay was 21.6 days, 24 days and 18 days for esophageal, pancreatic and gastric resections, respectively, with no difference between high and low volume departments. The hospital mortality was 8.6%, 8.9% and 8.2%, respectively.

Conclusion:

The overall high mortality and long postoperative stay in patients undergoing upper gastrointestinal cancer surgery in Denmark calls for improvement by regionalisation into 3–4 departments and monitoring of results.

Pig slurry acidification and separation techniques affect soil N and C turnover and N2O emissions from solid, liquid and biochar fractions

The combined effects of pig slurry acidification, subsequent separation techniques and biochar production from the solid fraction on N mineralisation and N2O and CO2 emissions in soil were investigated in an incubation experiment. Acidification of pig slurry increased N availability from the separated solid fractions in soil, but did not affect N2O and CO2 emissions. However acidification reduced soil N and C turnover from the liquid fraction. The use of more advanced separation techniques (flocculation and drainage > decanting centrifuge > screw press) increased N mineralisation from acidified solid fractions, but also increased N2O and CO2 emissions in soil amended with the liquid fraction. Finally, the biochar production from the solid fraction of pig slurry resulted in a very recalcitrant material, which reduced N and C mineralisation in soil compared to the raw solid fractions.

Life Cycle Assessment of Biogas Production in Small-scale Household Digesters in Vietnam

Small-scale household digesters have been promoted across Asia as a sustainable way of handling manure. The major advantages are that they produce biogas and reduce odor. However their disadvantages include the low recycling of nutrients, because digestate is dilute and therefore difficult to transport, and the loss of biogas as a result of cracks and the intentional release of excess biogas. In this study, life cycle assessment (LCA) methodology was used to assess the environmental impacts associated with biogas digesters in Vietnam. Handling 1,000 kg of liquid manure and 100 kg of solid manure in a system with a biogas digester reduced the impact potential from 4.4 kg carbon dioxide (CO2) equivalents to 3.2 kg CO2 equivalents compared with traditional manure management. However, this advantage could easily be compromised if digester construction is considered in the LCA or in situations where there is an excess of biogas which is intentionally released. A sensitivity analysis showed that biogas digesters could be a means of reducing global warming if methane emissions can be kept low. In terms of eutrophication, farms with biogas digesters had 3 to 4 times greater impacts. In order to make biogas digesters sustainable, methods for recycling digestates are urgently required.

The influence of the pig manure separation system on the energy production potentials

Energy recovery from pig manure offers an opportunity for waste utilisation and financial benefit. Samples of the solid fraction of separated pig manure and samples which had undergone chemical or biological pretreatment prior to separation were pyrolysed. A beech wood sample was pyrolysed for comparison. The chemically pre-treated and anaerobically digested materials had similar properties and showed similar behaviour during thermogravimetric analysis. However, the energy content of the gas arising from pyrolysis in a batch reactor at 600 °C comprises about 30% of the original energy of the feedstock in the case of the anaerobically digested materials and double that of the chemically pre-treated material. Therefore, the overall energy balance showed a loss of 595.9 MJ/t for the pyrolysis of the chemically pre-treated manure, while very small positive values of 351.7 MJ/t, 817.3 MJ/t and a significant value of 8935 MJ/t were found for anaerobically digested sample, un-pretreated solid and for wood, respectively.

Differences in outcomes of oesophageal and gastric cancer surgery across Europe

BACKGROUND

In several European countries, centralization of oesophagogastric cancer surgery has been realized and clinical audits initiated. The present study was designed to evaluate differences in resection rates, outcomes and annual hospital volumes between these countries, and to analyse the relationship between hospital volume and outcomes.

METHODS

National data were obtained from cancer registries or clinical audits in the Netherlands, Sweden, Denmark and England. Differences in outcomes were analysed between countries and between hospital volume categories, adjusting for available case-mix factors.

RESULTS

Between 2004 and 2009, 10 854 oesophagectomies and 9010 gastrectomies were registered. Resection rates in England were 18·2 and 21·6 per cent for oesophageal and gastric cancer respectively, compared with 28·5-29·9 and 41·4-41·9 per cent in the Netherlands and Denmark (P < 0·001). The adjusted 30-day mortality rate after oesophagectomy was lowest in Sweden (1·9 per cent). After gastrectomy, the adjusted 30-day mortality rate was significantly higher in the Netherlands (6·9 per cent) than in Sweden (3·5 per cent; P = 0·017) and Denmark (4·3 per cent; P = 0·029). Increasing hospital volume was associated with a lower 30-day mortality rate after oesophagectomy (odds ratio 0·55 (95 per cent confidence interval 0·42 to 0·72) for at least 41 versus 1-10 procedures per year) and gastrectomy (odds ratio 0·64 (0·41 to 0·99) for at least 21 versus 1-10 procedures per year).

CONCLUSION

Hospitals performing larger numbers of oesophagogastric cancer resections had a lower 30-day mortality rate. Differences in outcomes between several European countries could not be explained by differences in hospital volumes. To understand these differences in outcomes and resection rates, with reliable case-mix adjustments, a uniform European upper gastrointestinal cancer audit with recording of standardized data is warranted.

Enforcing centralization for gastric cancer in Denmark

BACKGROUND

Population-based data on the early postoperative outcome after surgery for gastric cancer are very sparse. We examined the development in the quality of surgery and early postoperative outcomes in Denmark following centralization of gastric cancer surgery and implementation of national clinical guidelines.

METHODS

All patients in Denmark who underwent resection with curative intent for gastric cancer between 1st July 2003 and 31st December 2008 in one of five university hospitals were registered in a national database. Data on surgical quality and mortality were obtained from the database and compared with the results from the period before centralization (1999-2003).

RESULTS

A total of 416 patients underwent resection in the study period. The risk of anastomotic leakages for the whole period was 5.0% (95%CI; 3.2-7.7) compared to 6.1% (95%CI; 4.3-8.6) before centralization, whereas the 30-days hospital mortality was 2.4% (95%CI; 1.2-4.4) compared to 8.2% (95%CI; 6.0-10.4) before centralization. In addition, the percentage of patients with at least 15 lymph nodes removed increased during the study period from 19 in 2003 to 76 in 2008.

CONCLUSIONS

Centralization of gastric cancer surgery in Denmark and implementation of national clinical guidelines monitored by a national database was associated with improvements in surgical quality and substantially lower in-hospital mortality.

Production of compact plants by overexpression of AtSHI in the ornamental Kalanchoë

Growth retardation is an important breeding aim and an essential part of horticultural plant production. Here, the potential of transferring the Arabidopsis short internode (shi) mutant phenotype was explored by expressing the AtSHI gene in the popular ornamental plant Kalanchoë. A 35S-AtSHI construct was produced and transferred into eight genetically different cultivars of Kalanchoë by Agrobacterium tumefaciens. The resulting transgenic plants showed dwarfing phenotypes like reduced plant height and diameter, and also more compact inflorescences, as a result of increased vegetative height. The shi phenotype was stable over more than five vegetative subcultivations. Compared with Arabidopsis, the ectopic expression of AtSHI in Kalanchoë showed several differences. None of the Kalanchoë SHI-lines exhibited alterations in leaf colour or morphology, and most lines were not delayed in flowering. Moreover, continuous treatment of lines delayed in flowering with low concentrations of gibberellins completely restored the time of flowering. These features are very important as a delay in flowering would increase plant production costs significantly. The effect of expression controlled by the native Arabidopsis SHI promoter was also investigated in transgenic Kalanchoë and resulted in plants with a longer flowering period. Two AtSHI like genes were identified in Kalanchoë indicating a widespread presence of this transcription factor. These findings are important because they suggest that transformation with the AtSHI gene could be applied to several species as a tool for growth retardation, and that this approach could substitute the use of conventional chemical growth regulation in plant production.

The quantification of paracetamol, paracetamol glucuronide and paracetamol sulphate in plasma and urine using a single high-performance liquid chromatography assay

A range of analytical methods exist for the determination of paracetamol in biological fluids. However, to understand the fate of paracetamol and the effect of other drugs on its disposition in vivo, the major metabolites require quantification in urine and plasma. A method to simultaneously quantify paracetamol, paracetamol glucuronide (PG) and paracetamol sulphate (PS) in plasma and urine with superior sensitivity is therefore desired, especially if the volume of plasma available is low. A simple isocratic reverse phase high-performance liquid chromatography (HPLC) assay with spectrophotometric detection has been developed. The method, requiring only 100 microl of plasma and 50 microl of urine, utilizes a reversed-phase C18 column, a wavelength of 254 nm for detection and a mobile phase composed of potassium dihydrogen orthophosphate (0.1 M)-isopropanol-tetrahydrofuran (THF) (100:1.5:0.1, v/v/v) adjusted to pH 3.7 with phosphoric acid. The method is sensitive and linear in plasma within a concentration range from 0.4 to 200 microM for paracetamol, PG and PS. For PG and PS in urine, the method is sensitive and linear within a concentration range from 100 to 20,000 microM. Over these ranges, accuracy and precision were less than 12%. The assay has been used to measure concentrations of paracetamol and the two metabolites in plasma collected by finger-prick sampling and of the metabolites in urine from healthy volunteers administered a single oral dose of 1000 mg of paracetamol.

Evidence-based strategies for preventing drug administration errors during anaesthesia

We developed evidence-based recommendations for the minimisation of errors in intravenous drug administration in anaesthesia from a systematic review of the literature that identified 98 relevant references (14 with experimental designs or incident reports and 19 with reports of cases or case series). We validated the recommendations using reports of drug errors collected in a previous study. One general and five specific strong recommendations were generated: systematic countermeasures should be used to decrease the number of drug administration errors in anaesthesia; the label on any drug ampoule or syringe should be read carefully before a drug is drawn up or injected; the legibility and contents of labels on ampoules and syringes should be optimised according to agreed standards; syringes should (almost) always be labelled; formal organisation of drug drawers and workspaces should be used; labels should be checked with a second person or a device before a drug is drawn up or administered.

[Complications of cholecystectomy before and after introduction of laparoscopic surgery]

OBJECTIVES

In the University Department of Surgical Gastroenterology, Arhus University Hospital, the frequency of complications to acute and elective cholecystectomy was investigated before and after introduction of laparoscopic cholecystectomy.

MATERIAL AND METHODS

A retrospective survey turned up 1768 patients in the period of conventional open surgery (1974-1985) and 1432 patients in the laparoscopic period (1991-1998). All patients with exploration of the common bile duct were excluded.

RESULTS

In the open period 12 patients (0.68%) had lesions of the common bile duct requiring reconstruction. In patients operated on with laparoscopic cholecystectomy, lesions of the common bile duct were found in three patients (0.21%) (p = 0.06). Lesions of the cystic duct or an aberrant bile duct occurred in 14 patients (0.79%) during the open period and in 24 patients (1.7%) (p < 0.05) operated on with the laparoscopic technique. Infectious and cardiopulmonary complications were seen in significantly more patients operated on with the open technique.

DISCUSSION

It is concluded that laparoscopic cholecystectomy offers a safe procedure, although the technique can still be improved, especially with respect to decreasing leakage from the cystic duct.

Systemic and cell-mediated immune response after laparoscopic and open cholecystectomy in patients with chronic liver disease. A randomized, prospective study

BACKGROUND

As impaired immune function observed in cirrhotic patients is known to increase the risk of postoperative complications, the immunological response to surgery was investigated.

METHODS

Twenty-eight patients with postnecrotic liver cirrhosis or chronic hepatitis C and symptomatic gallstone disease were randomly allocated to laparoscopic (LC) or open cholecystectomy (OC). Changes in concentrations of cytokines (TNF-alpha, IL-1beta, IL-6, IL-8 and IL-10) were followed and the effect of surgical trauma on the distribution of lymphocyte subpopulations (CD3, CD4, CD8, CD16 and CD19) and NK cell cytotoxicity were measured.

RESULTS

After OC a decrease in circulating CD3 (p < 0.05) and CD4 (p < 0.05) and an increase in CD19 (p < 0.05) cells were detected in contrast to LC after which only CD16 cells decreased (p = 0.05). The number of CD3 cells was higher after LC than after OC (p < 0.01), whereas the number of CD19 cells was higher after OC than after LC (p < 0.01). NK cell cytotoxicity was reduced after LC (p < 0.05). In cirrhotic patients circulating cytokines were unaffected by OC, whereas TNF-alpha (p < 0.05) and IL-1beta (p < 0.05) were reduced after LC. In chronic hepatitis IL-1beta decreased after OC (p = 0.05) and IL-10 was significantly higher after LC than following OC (p < 0.05).

CONCLUSION

The immune response is less pronounced after a laparoscopic procedure compared to a conventional approach in patients with chronic liver disease.

Postoperative hepatic catabolic stress response in patients with cirrhosis and chronic hepatitis

Open (OC) or laparoscopic (LC) cholecystectomy is considered a relative contraindication in patients with liver cirrhosis. The effect of LC and OC on the hepatic catabolic stress response was studied in patients with postnecrotic liver cirrhosis and chronic hepatitis to define the most suitable procedure from a metabolic point of view. Altogether 14 patients with cirrhosis and 14 with chronic hepatitis were randomized to LC or OC (n = 7 in each group). The increase in the functional hepatic nitrogen clearance (FHNC) was quantified. Changes in glucose, insulin, glucagon, cortisol, epinephrine, norepinephrine, and prostaglandin E(2) (PGE(2)) were observed. There was no difference in FHNC between LC and OC in any of the patients. Among cirrhotic patients OC caused a 132% increase in FHNC (p < 0.05) and among the hepatitis patients a 69% increase (p < 0.05). In contrast, there was no significant increase following LC in any of the patients. OC increased fasting glucose and insulin in the hepatitis patients (p < 0.01 and p < 0.001, respectively) and in the cirrhosis group (p < 0.01 and p < 0.05, respectively). Alanine stimulation increased glucose in hepatitis patients after OC (p < 0.05) and after LC (p < 0.01). Stimulated glucagon increased after OC in the hepatitis group (p < 0.05). During stimulation cortisol was higher following LC in hepatitis patients (p < 0.01) and cirrhotic patients (p < 0.05). Fasting PGE(2) was down-regulated after LC in hepatitis patients (p < 0.05) and cirrhotic patients (p < 0.01) and after OC in the hepatitis group (p < 0.001). FHNC is similar after LC and OC. Thus from a metabolic point of view, LC has no advantage over OC.

Benefits of leukocyte-reduced blood transfusions in surgical patients

From a surgical point of view, one of the most important consequences of blood transfusion is the immunosuppressive effect and its possible link to postoperative infectious complications and cancer recurrence. The underlying mechanism of transfusion-induced immunosuppression seems to be mediated by transfusion with leukocytes. In prospective randomized trials, therefore, efforts have been made to control the immunosuppressive effect of allogeneic blood transfusion by the use of leukocyte-reduced blood. Only one prospective clinical trial has asserted the effect of leukocyte reduction on cancer recurrence, and no benefit to outcome was found. In four big randomized, prospective clinical trials, allogeneic blood transfusion was associated with significantly increased rates of postoperative infections, and the use of leukocyte reduction was found to have striking benefits in three of the trials, with a several-fold reduction in rates of morbidity and mortality.

The effect of ranitidine on postoperative infectious complications following emergency colorectal surgery: a randomized, placebo-controlled, double-blind trial

OBJECTIVE AND DESIGN

To study the potential effect of ranitidine on postoperative infectious complications following emergency colorectal surgery. A randomized, placebo-controlled, double-blind trial was carried out in three university clinics and two county hospitals in Denmark.

PATIENTS AND TREATMENT

One hundred and ninety-four consecutive patients undergoing acute colorectal surgery for perforated and/or obstructed large bowel were randomized in a double-blind fashion to receive ranitidine 100 mg i.v. twice a day commencing at induction of anesthesia and continued for five days (group I) or i.v. placebo (group II). All patients were given 1.5 g metronidazole plus 3.0 g cefuroxime at the time of surgery. Patients with perforation of the colon or rectum were given metronidazole and cefuroxime for further 3 days. All patients were assessed daily until discharge from the hospital. Thirty patients were withdrawn from the study (for reasons such as other diagnosis, refused to continue, medication not given as prescribed).

MAIN OUTCOME MEASURES

Patients were observed for signs of infectious complications; such as wound infection, intra-abdominal abscess, septicemia, and pneumonia.

RESULTS

Both groups were similar with respect to age, sex, weight, duration of surgery, blood transfusions, and site of the procedure, as well as the histologic nature of the underlying disease process. However, the Mannheim Peritonitis Index (MPI) was significantly higher in group I compared with group II (p < 0.05). Wound infection, intraabdominal abscess, septicemia, and pneumonia were 12.9%, 5.2%, 3.8% and 14%, respectively in group I. In group II, the infectious complications were 16.1%, 6.8%, 6.9% and 22%, respectively. Twelve patients (13.8%) in the placebo group developed more than one complication compared with 5 patients (6.5%) in the ranitidine group.

CONCLUSION

Ranitidine may have a beneficial effect on postoperative infectious complications in patients following acute colorectal surgery.

[Leukocyte filtration in elective colorectal surgery. Reduced transfusion associated immunosuppression after bedside procedures]

The objective of the study was to investigate certain immune parameters in patients undergoing elective colorectal surgery and receiving either whole blood transfusion or leucocyte-filtrated blood. Sixty consecutive patients were randomly allocated to receive either whole blood transfusion or leucocyte-filtrated blood leucocyte when transfusion was indicated. The immune parameters were investigated on the day of surgery and on day 3, 7 and 30 postoperatively. Transfusion with whole blood was followed by a significant decrease in lymphocyte proliferation and CD4+/CD8+ ratio (p < 0.01) as well as a significant increase in soluble interleukin-2 receptor and interleukin-6 (p < 0.01). Furthermore transfusion with whole blood was accompanied by a significant increase in postoperative infectious complications (p < 0.01). Patients transfused with leucocyte-filtrated blood had only minor and passing changes in the immune parameters and developed no infectious complications, indicating that effective leucocyte filtration abolishes transfusion-associated immunosuppression.

Randomised comparison of leucocyte-depleted versus buffy-coat-poor blood transfusion and complications after colorectal surgery

BACKGROUND

Allogeneic blood transfusion is associated with an increased frequency of postoperative infection. We studied whether such events can be avoided by the intraoperative and postoperative use of leucocyte-depleted blood.

METHODS

589 consecutive patients scheduled for elective colorectal surgery were randomised to receive buffy-coat poor (n = 299) or filtered leucocyte-depleted red-cells (n = 290) when transfusion was indicated. 260 patients actually received blood transfusion. Three patients were excluded from analysis.

FINDINGS

The 142 patients randomised to and transfused with buffy-coat-poor blood had a significantly higher frequency of wound infections and intra-abdominal abscesses than the 155 patients who were allocated to this group but who were not transfused. (12 vs 1%, p < 0.0001) and (5 vs 0%, p = 0.005), respectively. Those receiving buffy-coat-poor blood also had a significantly higher frequency of wound infections and intra-abdominal abscesses than the 118 randomised to and receiving leucocyte-depleted blood (12 vs 0%, p < 0.0001) and (5 vs 0%, p = 0.017), respectively. Postoperative pneumonia occurred at a significantly higher rate in patients receiving buffy-coat-poor blood: 23 versus 3% in non-transfused patients (p < 0.0001), and 23 versus 3% in patients transfused with leucocyte-depleted blood (p < 0.001). The mortality rate between the groups was not statistically different.

INTERPRETATION

Our data suggests that the association between allogeneic blood transfusion and postoperative infection is limited to allogeneic blood products that are not adequately depleted of immunosuppressive leucocytes. This undesirable effect can be reduced by leucocyte depletion with high-efficiency filters.

A randomized controlled study of the effect of bedside leucocyte depletion on the immunosuppressive effect of whole blood transfusion in patients undergoing elective colorectal surgery

In a randomized study the effect of whole blood transfusion versus bedside leucocyte-depleted blood transfusion on lymphocyte proliferation, CD4+:CD8+ ratio, and levels of soluble interleukin 2 receptor (sIL-2R) and interleukin (IL) 6, as well as on the development of postoperative wound infection and intra-abdominal abscess, was assessed in 60 patients undergoing elective colorectal surgery. Transfusion with whole blood induced a significant decrease in lymphocyte proliferation and CD4+ :CD8+ ratio (P < 0.01) as well as a significant increase in sIL-2R and IL-6 levels (P < 0.01). Furthermore, transfusion with whole blood was accompanied by a significant increase in postoperative infectious complications (P < 0.01). In patients transfused with leucocyte-depleted blood only slight and transient changes were observed, which were not significantly different from those observed in non-transfused patients.

Bleeding oesophageal varices

BACKGROUND

The Danish contribution to evaluation and treatment of bleeding oesophageal varices.

METHODS

Danish papers dealing with portal hypertension and oesophageal varices have been reviewed and set in relation to international publications.

RESULTS

The Danish papers have mainly contributed with controlled clinical trials concerning both primary and secondary prophylaxis. Furthermore, they have dealt with pathophysiologic, clinical and experimental studies concerning portal haemodynamics and the evolution and treatment of variceal bleeding.

CONCLUSION

The Danish studies have been well designed and are frequently cited. Further prospective randomized studies in the new treatment modalities are encouraged.

Systemic treatment with epidermal growth factor induces anaemia in Goettingen minipigs

1. From two independent experimental studies conducted in 48 minipigs with oesophageal sclerotherapy and concomitant treatment with epidermal growth factor, blood samples together with bone marrow biopsies were analysed for safety data. 2. Four to five weeks of systemic treatment with epidermal growth factor induced a decline in blood haemoglobin concentration in a time- and dose-dependent and reversible manner but without an effect on leucocyte or platelet counts. 3. The bone marrow expressed decreased amounts of haematopoietic tissue and reduced numbers of erythropoietic cells. 4. Four to five weeks of systemic treatment with epidermal growth factor induced reversible increases in serum concentrations of creatinine and urea, most likely reflecting renal impairment. 5. Groups in which creatinine and urea were not increased also had reduced blood haemoglobin concentrations. 6. These findings suggest that epidermal growth factor selectively impaired the erythropoiesis and stress the importance of risk-benefit analysis concerning the potential therapeutic applications of epidermal growth factor.

Cost-effectiveness of blood transfusion and white cell reduction in elective colorectal surgery

BACKGROUND

The use of white cell (WBC)-reduced blood in elective colorectal surgery appears to reduce the frequency of postoperative infection. The question to be addressed is whether the cost:benefit ratio justifies the recommendation that WBC-reduced blood should be used for all colorectal surgery.

STUDY DESIGN AND METHODS

Patients admitted for elective colorectal surgery (n = 197) were randomly assigned to receive transfusion consisting of whole blood or WBC-reduced whole blood. Postoperative complications, postoperative stay, and hospital charges were compared.

RESULTS

Forty-eight patients received WBC-reduced whole blood, 56 received unfiltered whole blood, and 93 received no transfusion. Postoperative infections were significantly higher (p < 0.001) in the group that received unfiltered whole blood. That group also had longer hospital stays: 17 days as compared to stays of 10 and 11 days for the group receiving no transfusion and the group receiving filtered whole blood transfusions, respectively (p < 0.01). The total hospital cost per patient receiving unfiltered whole blood was $12,347, as compared to $7,867 for those who received WBC-reduced whole blood and $7,030 for those who received no transfusion.

CONCLUSION

The use of WBC-reduced whole blood transfusions in elective colorectal surgery significantly reduces the frequency of postoperative infection, the length of hospital stay, and the total hospital charges for patients needing blood transfusion.

Preventive effects of recombinant human epidermal growth factor on the oesophageal epithelium in pigs subjected to sclerotherapy

OBJECTIVE

To investigate the role of epidermal growth factor (EGF), a small (relative molecular mass 6000) polypeptide with mitogenic properties in the protection of gastrointestinal mucosal integrity.

DESIGN

A prospective, randomized and blinded study.

METHODS

Twenty-four minipigs with surgically induced portal hypertension underwent four consecutive weekly sessions of oesophageal sclerotherapy with 5 ml 1% polidocanol and were concomitantly treated with either a placebo or human recombinant EGF administered subcutaneously. Mucosal damage was evaluated on a weekly basis by endoscopic estimation of the size of the ulcerated area and by post-mortem morphometry. The EGF-induced morphological changes in the oesophageal epithelium were also evaluated histologically.

RESULTS

In sclerosed and non-sclerosed parts of the oesophagus EGF significantly increased the thickness of the oesophageal epithelium (P < 0.03), but failed to reduce significantly the degree of oesophageal damage associated with sclerotherapy (P = 0.11).

CONCLUSIONS

Systemic EGF treatment induces proliferation of the oesophageal mucosa, and EGF may therefore have the potential to reduce sclerotherapy-induced oesophageal damage.

Daily energy allotments and performance of broiler breeders. 1. Males

The effects of daily energy intake on reproductive performance of Arbor Acres males and on growth of their offspring was studied. In Experiment 1, 21 males were placed in individual pens with 12 females. Three rations, differing in energy, were fed from 24 to 57 wk of age with seven males receiving either 300, 340, or 380 kcal ME/d. In Experiment 2, 32 individually caged males were given daily allotments of 280, 320, 360, or 360 kcal ME/d from 26 to 32 wk of age and 300, 340, 380, or 380 kcal ME/d from 32 to 38 wk. Rations of the two groups of males fed the highest energy level differed in formulation, one being the same wheat short-based basal ration as fed to the two lower energy groups, only with additional fat, and the other being a corn-soybean-based ration. Body weight and testes weight were increased with increased energy allotment in both experiments but carcass composition was unaltered. There were no significant effects of energy intake on fertility or hatchability in either experiment. Even though mean differences were not significant, fertility in two pens dropped to near zero at 38 wk in Experiment 1. Semen characteristics and plasma testosterone concentrations were unaffected by energy intake in Experiment 2. There was a significant linear increase in 6-wk BW of broilers associated with the increase in sire energy intake in each of three batches of broilers grown in Experiment 1 and in one of two batches of broilers grown in Experiment 2.

Daily energy allotments and performance of broiler breeders. 2. Females

Arbor Acres broiler breeder hens, 21 to 61 wk of age, were given the daily ME level recommended by the primary breeder for their age and level of production (100% AA) or were given 94 or 88% of that amount. The reduction in daily energy allotment had no effect on age at 50% or age at peak production, but there was a highly significant linear decrease in the eggs per hen from 165 +/- 2.8 in hens given 100% AA to 149 +/- 3.2 and 141 +/- 3.8 in hens given 94 and 88% AA. The percentage of nonlaying hens between 44 and 60 wk of age was substantially increased as daily energy allotment was reduced. The percentage settable eggs was significantly lower in the 100% AA group, but no differences in fertility or hatchability were seen. Chicks per hen fell from 123 +/- 2.4 to 116 +/- 2.4 to 102 +/- 2.6 as energy allotment was progressively reduced. Dietary energy allotment had no effect on egg weight, shell weight, shell characteristics, or proportion of albumen and yolk. Chick weight was unaffected but chicks' liver weight increased with increasing dam energy intake. Percentage lipid in hens' carcasses increased with increasing energy intake and percentage protein and percentage ash decreased.

Systemic treatment with recombinant human epidermal growth factor accelerates healing of sclerotherapy-induced esophageal ulcers and prevents esophageal stricture formations in pigs

Human epidermal growth factor (EGF), a small polypeptide (6 kDa) with mitogenic properties, has been implicated in the protection of gastrointestinal mucosal integrity. The efficacy of EGF in the prevention and healing of sclerotherapy-induced esophageal lesions was investigated in 24 minipigs with surgically induced portal hypertension. In addition, the effect of EGF on intragastric acidity and pharmacokinetics was investigated as possible means to explain its protective mechanism of action. The animals underwent three weekly sessions of sclerotherapy with polidocanol 2% and were concomitantly and for an additional three weeks treated with either placebo or EGF administered paravenously in the esophagus and/or subcutaneously. The subcutaneous treatment with EGF significantly (P < 0.05) reduced esophageal stricture and scar formations associated with sclerotherapy. Gastric pH values were significantly (P < 0.01) elevated only in animals receiving subcutaneous injections of EGF. Furthermore, the subcutaneous administration of EGF was associated with unexpected prolonged plasma concentration of the peptide. These results suggest a possible clinical value of EGF as an adjunctive treatment with the sclerotherapy.

Recombinant human epidermal growth factor prevents sclerotherapy-induced esophageal ulcer and stricture formations in pigs

Human epidermal growth factor (EGF), a naturally occurring protein, has been implicated in the protection of gastrointestinal mucosal integrity. The efficacy of EGF in the prevention of sclerotherapy-induced esophageal lesions was investigated in 18 minipigs with surgically induced portal hypertension. The animals underwent five weekly sessions of sclerotherapy with polidocanol 2% and were concomitantly treated with either placebo or EGF administered either paravenously or subcutaneously. EGF significantly (P < 0.05) reduced esophageal ulcerations, stricture formations, and mucosal histological damage associated with sclerotherapy. The drug was well-tolerated with no overt toxicity. These results suggest a potentially important clinical value of EGF as an adjunctive treatment with the sclerotherapy.

[Blood transfusion increases the risk of surgical infection]

In a prospective randomized trial the frequency of infectious complications and natural killer cell function were investigated in 197 patients undergoing elective colorectal surgery and having either no blood transfusion (n = 93), transfusion with whole blood (n = 56), or filtered blood free from leucocytes (n = 48). Postoperative infections developed in 13 patients transfused with whole blood (23%), in one patient transfused with blood free from leucocytes (2%) and in two non-transfused patients (2%) (p < 0.01). Natural killer cell function was significantly (p < 0.001) impaired up to 30 days after surgery in patients transfused with whole blood. These data provide a strong case against the use of whole blood transfusion in patients undergoing elective colorectal surgery.

The hypocholesterolemic agent dichloroacetate increases egg cholesterol content of laying hens

Experiments were conducted to determine whether a diet with added dichloroacetate (DCA), an inhibitor of cholesterol biosynthesis, would influence plasma and egg cholesterol concentrations when fed to laying hens. In the first experiment, 62-wk-old laying hens (10 hens per treatment) were fed a control diet containing 0, 350, 700, or 1,400 ppm DCA for an 8-wk period. Egg production and size, feed intake, weight gain, and plasma and egg cholesterol were determined at biweekly intervals. In a second experiment, 36-wk-old laying hens (eight hens per treatment) received diets with 0, 3,000, or 6,000 ppm added DCA for a period of 6 wk. Production parameters and cholesterol measurements were conducted as in Experiment 1. Egg production and feed intake were significantly decreased with increasing levels of DCA in Experiment 1. In the second experiment, 6,000 ppm DCA sharply reduced feed intake, body weight, and egg production. Yolk weight and percentage yolk were significantly decreased by the higher levels of DCA used in Experiment 2. Total plasma cholesterol was not affected by dichloroacetate in either of the experiments. In contrast, egg cholesterol concentration increased by 10 and 37% in Experiments 1 and 2, respectively, in response to diets with added DCA when compared with the unsupplemented controls. Total egg cholesterol increased in response to dietary DCA in Experiment 1, but not consistently in Experiment 2 due to the decreased yolk size of the hens fed DCA. The results of these studies indicate that dietary DCA was not effective in reducing egg cholesterol concentrations.

Reduced plasma cholesterol and lipoprotein in laying hens without concomitant reduction of egg cholesterol in response to dietary sorbose

Experiments were conducted to determine the effect of sorbose on feed consumption, egg production and size, and cholesterol metabolism of laying hens. In Experiment 1, 87-wk-old laying hens (10 per treatment) were fed diets containing 0, 10, or 20% sorbose for 4 wk. In a second experiment, 108-wk-old laying hens (eight per treatment) were fed a control diet, a diet with 10% added sorbose, or the control diet with intake restricted to the level of sorbose-treated hens for 4 wk. Feed consumption and egg production were recorded daily. Plasma and egg cholesterol levels were determined at 0, 2, and 4 wk. Plasma and egg very low density lipoprotein (VLDL) concentrations were determined after 4 wk. Egg production, feed intake, and body weight gain were significantly reduced by dietary sorbose. Egg and yolk weight and percentage yolk decreased in response to sorbose. Sorbose significantly reduced plasma cholesterol and VLDL by approximately 50%, compared with the hens fed a control diet. Egg cholesterol concentration (milligrams per gram of yolk) was significantly increased, although the reduction in yolk size resulted in similar total egg cholesterol (milligrams per egg). Restricting feed intake of laying hens significantly lowered plasma cholesterol, but not to levels comparable to that of sorbose-treated hens. The data indicate that substantial reduction of plasma cholesterol and VLDL by dietary sorbose was not accompanied by reduced egg cholesterol.

Postoperative infection and natural killer cell function following blood transfusion in patients undergoing elective colorectal surgery

The frequency of infection in 197 patients undergoing elective colorectal surgery and having either no blood transfusion, transfusion with whole blood, or filtered blood free from leucocytes and platelets was investigated in a prospective randomized trial. Natural killer cell function was measured before operation and 3, 7 and 30 days after surgery in 60 consecutive patients. Of the patients 104 required blood transfusion; 48 received filtered blood and 56 underwent whole blood transfusion. Postoperative infections developed in 13 patients transfused with whole blood (23 per cent, 95 per cent confidence interval 13-32 per cent), in one patient transfused with blood free from leucocytes and platelets (2 per cent, 95 per cent confidence interval 0.05-11 per cent) and in two non-transfused patients (2 per cent, 95 per cent confidence interval 0.3-8 per cent) (P less than 0.01). Natural killer cell function was significantly (P less than 0.001) impaired up to 30 days after surgery in patients transfused with whole blood. These data provide a strong case against the use of whole blood transfusion in patients undergoing elective colorectal surgery.

Growth and tissue lipid deposition of broilers fed alpha-ketoisocaproic acid

Dietary alpha-ketoisocaproic acid (KIC) was studied for effects on growth, feed efficiency, tissue cholesterol (TC) content, and immune response to a Newcastle disease virus (NDV) vaccination in broilers. In two experiments, broiler chicks were fed diets supplemented with graded levels of KIC to .54% of the diet. Feed efficiency, fat deposition, BW gain, and plasma cholesterol levels were determined at 3 wk. In a third experiment, broilers were fed diets supplemented with 0, .1, .2, and .4% KIC throughout the starter (0 to 3 wk), grower (3 to 6 wk), and finisher (6 to 7 wk) periods. Abdominal fat and plasma and breast TC were measured at 7 wk. In Experiment 4, levels of KIC to .6% were fed to broilers to determine TC content and to measure the immune response to NDV vaccination. Feed efficiency, BW gain, and percentage abdominal fat were not affected by KIC in any of the broiler experiments. The addition of KIC to broiler diets resulted in a significant reduction in breast (Pectoralis major) TC. Biceps (Biceps femoralis) TC, adductor (Pubo-ishio-femoralis) TC, and plasma cholesterol content was not affected by KIC. Geometric mean titers to NDV were not improved by KIC. The data indicate that KIC has no effect on growth or abdominal fat deposition, but may have a role in TC homeostasis.

Influence of dietary taurine on performance and fat retention in broilers and turkey poults fed varying levels of fat

Taurine, an amino acid synthesized from Met, primarily functions in bile acid conjugation. Four experiments were conducted to determine whether Tau supplementation of broiler cockerels and female turkey poults to 3 wk of age would influence performance and fat retention at different levels of dietary fat. In these experiments, Tau was added at 0 or .8% to a corn and soybean meal basal diet with dietary poultry fat added at 0, 5, or 10%. Taurine did not affect BW gain of broiler cockerels; however, in one experiment feed efficiency was improved (P less than .01) during the 1st wk and fat retention was improved (P less than .06) at 7 days of age. In experiments with turkey poults, dietary Tau did not affect weight gain but improved feed efficiency (P less than .01) during the 1st wk and decreased overall feed efficiency (P less than .01) in one experiment. Improvement of fat retention by Tau at 14 days was significant (P less than .02) in one experiment and approached significance (P less than .07) in the other experiment. Fat supplementation of both the broiler and turkey diets significantly (P less than .05) improved weight gain, feed efficiency, and fat retention. Supplementary Tau appears to have little effect on performance of broilers and turkeys.

Cholesterol concentration of egg yolk and blood plasma and performance of laying hens as influenced by dietary alpha-ketoisocaproic acid

Experiments were conducted to determine the effect of supplemental alpha-ketoisocaproic acid (KIC) or Leu on layer performance and plasma and egg cholesterol levels. In the first experiment, 0, .09, or .27% KIC and .09 or .27% Leu were fed to 62-wk-old laying hens. In a second experiment, the same levels plus another level of .54% KIC and .54% Leu were fed to 32-wk-old hens for an 8-wk period. The basal diet or the basal diet supplemented with .27% KIC or .27% Leu were continued for 20 wk to determine the long-term effects of these supplements. In a third experiment, hens were fed 0, .1, .2, or .4% KIC for 8 wk. The addition of KIC and Leu to the hen diets did not affect percentage egg production, egg weight, shell thickness, or Haugh units. In Experiment 1, .27% KIC and .09% Leu significantly increased BW gain. Neither KIC or Leu significantly affected BW gain in Experiment 2 when measured at 8 or 28 wk. In the third experiment, diets supplemented with KIC increased significantly BW gain. In Experiment 1, .09% KIC and .09% Leu significantly reduced egg cholesterol at 4 wk. After 8 wk, .27% KIC reduced egg cholesterol significantly below the controls. No effect on plasma or egg cholesterol was observed in Experiments 2 and 3.

Research note: putrescine effects on performance of male broiler chicks fed low-protein diets supplemented with essential amino acids

The purpose of the present study was to determine whether a polyamine deficiency could account for the reduced performance of broiler chicks fed a low-protein diet supplemented with several synthetic amino acids in comparison with those fed a more conventional CP concentration. Male broiler chicks were fed equicaloric diets calculated to contain 23, 20, or 17% CP. Each diet was supplemented with 0, .05, or .10% putrescine in a 3 x 3 factorial arrangement of treatments. Body weight gain of chicks fed the 17% CP diet was significantly (P less than .05) less than that of those fed the higher protein diets and feed conversion ratio significantly increased as the CP concentration decreased. Adding putrescine failed to significantly affect any of the parameters within each CP concentration. A deficiency of polyamines does not appear to explain the lower performance of broiler chicks fed low CP diets with added synthetic amino acids.

Effect of age of hen, egg weight, and sex on chick performance and lipid retention

Experiments were conducted to determine whether age of hen, weight of the egg, and sex of the chick affected fat retention and growth of the broiler chick. Chicks were fed a corn and soybean meal diet containing 5% supplemental poultry fat. In the first study, eggs from two ages of hens were compared (30 and 52 wk) with six egg weight classes per age. The second experiment consisted of three hen ages (31, 37, and 47 wk) with three egg weight classes per age. The results indicated that as hen age and egg weight increased, BW gain of the chicks increased but feed efficiency and fat retention were not affected. Females had improved fat retention when compared with males. When analyzed within each egg weight class, there was no age effect on fat retention, BW gain, or feed efficiency.

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

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

Influence of orotic acid on performance, liver lipid content, and egg cholesterol level of laying hens

Three experiments were conducted to determine the effects of dietary orotic acid (OA) on laying hen performance, liver lipid content, and plasma and egg cholesterol levels. Laying hens were fed a basal diet supplemented with 0, .5, 1.0, and 2.0% OA for 8 wk. Performance of the hens and cholesterol levels were measured at biweekly intervals. In all three experiments, OA decreased (P less than .05) BW in a linear manner. In two experiments, OA caused a linear decrease in total liver lipid (P less than .05), and in a third experiment OA resulted in a quadratic effect (P less than .01) on liver lipid content. There were no effects observed by OA supplementation on egg weight, yolk weight, percentage yolk, or egg production. Orotic acid failed to influence egg cholesterol content in any of the biweekly measurements of the three experiments. In two experiments, total plasma cholesterol content was not influenced by OA supplementation. Orotic acid significantly reduced (P less than .05) free and total plasma cholesterol in a third experiment when measured at Weeks 4, 6, and 8 of the experiment. The data indicate that OA is an ineffective dietary supplement for reducing egg cholesterol levels in laying hens.