A formal method of determining the dietary amino acid requirements of laying‐type pullets during their growing period

1. The amino acid requirements of laying type pullets during the growing period can be estimated by measuring the growth of different components of the body and making use of nutritional constants that define the amount of each amino acid that is required for the production of the tissues being formed.

2. In this experiment, carcase analyses of each of three breeds of pullets were conducted at weekly intervals throughout the growth of the pullets, to 18 weeks of age. Measurements were made of body weight, gut‐fill and feather weight, and chemical analyses consisted of water, protein, lipid and ash measurements of both the body and the feathers. Each age group comprised 10 birds of each breed.

3. Gompertz functions accurately estimated the growth of both body protein and feather protein, to 18 weeks of age, from which the rate of growth of these two components of the body could be estimated. The mature weight of pullets was overestimated by the Gompertz growth curve, which may indicate that a pullet ceases to increase in body protein content once sexual maturity has been reached.

4. Using allometric relationships between the chemical components of the body and of feathers, all the components of growth could be estimated from the growth of body protein and feather protein. These components were then added together to determine the growth rate of the body as a whole.

5. The daily amino acid requirements for 4 functions were calculated, namely, those for the maintenance of body protein and feather protein, and for the gain in body protein and feather protein. These requirements were then summed to determine the requirement of pullets on each day of the growing period.

6. Using the ‘effective energy’ system, the amount of energy required by these pullets was calculated for each day of the growing period, from which the desired daily food intake of the pullets could be predicted. By dividing the amino acid requirement by this daily food intake it was possible to determine the concentration of amino acids that would be needed in the diet in order to meet the requirements of a pullet.

7. The results indicate that the ratio between the requirement for lysine and for methionine and cysteine changes dramatically during the growing period, negating the concept of a fixed ratio between all the amino acids during growth.

8. The above process is the first step in determining the optimal feeding programme for a population of pullets of a given genotype. The constraining effects, of the diet being offered and of the environment in which the pullets are housed, on the food intake and growth rate of each pullet have to be estimated, and such a theory can then be expanded to include all the individuals in the population. Only by the use: of simulation models can all these constraining effects be considered simultaneously.     

Serum lipase determination in the dog: a comparison of a titrimetric method with an automated kinetic method

An enzymatic, kinetic method for determining serum lipase activity was evaluated and compared to a standard manual method for use in dogs. The kinetic method was a commercial kit adapted for use on a tandem access clinical chemistry analyzer and utilized a series of coupled enzymatic reactions based on the hydrolysis of 1,2-diglyceride by lipase. The manual method was the Cherry-Crandall technique based on the titration of base against the acid formed by hydrolysis of an olive oil substrate by lipase. The correlation between the two methods was very good (r = 0.94). The reference range for 56 clinically healthy dogs assayed by the kinetic method was 90 to 527 U/L. Diseases associated with a greater than twofold elevation in serum lipase activity as determined by the kinetic method included pancreatitis, gastritis with liver disease, and oliguric renal failure with metabolic acidosis. In some cases, pancreatitis was seen with other clinical problems, such as gastroenteritis, diabetic ketoacidosis, duodenal mass, disseminated intravascular coagulation, and septic peritonitis. Diseases associated with serum lipase activity within the reference range or elevated less than twofold included gastritis, gastric ulcer, cholestasis, phenobarbital-induced hepatopathy, colitis, copper hepatopathy, abdominal hematoma, apocrine gland adenocarcinoma, and thrombocytopenia with pneumonia.     

Effects of diet restriction on life span and age-related changes in dogs

OBJECTIVE: To evaluate the effects of 25% diet restriction on life span of dogs and on markers of aging. DESIGN: Paired feeding study. ANIMALS: 48 Labrador Retrievers. PROCEDURES: Dogs were paired, and 1 dog in each pair was fed 25% less food than its pair-mate from 8 weeks of age until death. Serum biochemical analyses were performed, body condition was scored, and body composition was measured annually until 12 years of age. Age at onset of chronic disease and median (age when 50% of the dogs were deceased) and maximum (age when 90% of the dogs were deceased) life spans were evaluated. RESULTS: Compared with control dogs, food-restricted dogs weighed less and had lower body fat content and lower serum triglycerides, triiodothyronine, insulin, and glucose concentrations. Median life span was significantly longer for dogs in which food was restricted. The onset of clinical signs of chronic disease generally was delayed for food-restricted dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that 25% restriction in food intake increased median life span and delayed the onset of signs of chronic disease in these dogs.     

A Combination Chemotherapy Protocol (VELCAP-L) for Dogs with Lymphoma

Ninety-eight dogs with lymphoma treated with a 5-drug combination chemotherapy regimen (vincristine, L-asparaginase. cyclophosphamide, doxorubicin, prednisone [VELCAP-L]) were evaluated for pretreatment characteristics predictive for response and remission duration. The complete remission rate was 69%, with a median remission duration of 55 weeks. Dogs with advanced stage of disease, constitutional signs, dogs that were older, and dogs that were dyspneic were less likely to achieve remission. Once in remission, small dogs and dogs without pretreatment thrombocytopenia were likely to have longer remission duration. Toxicoses were frequent, but rarely fatal, and no predictitive factors were found for a dog developing toxicoses. VELCAP-L is an effective treatment for dogs in stage I-III lymphoma, particularly in young, small animals.     

Delineating foraging grounds of a loggerhead turtle population through satellite tracking of juveniles

1. Tracking of juvenile sea turtles is a research priority to inform the protection of relevant habitats and ensure sustainable rates of recruitment into adult populations. Based on satellite tracking, mixed stock analysis, and mark–recapture studies, Drini Bay in the South Adriatic Sea, Central Mediterranean, has been confirmed as an important foraging site used by loggerhead turtles from all major rookeries in the Mediterranean subpopulation.
2. Three juvenile loggerhead turtles (Caretta caretta) from Drini Bay were tracked for 763, 364, and 211 days respectively. All turtles exhibited different movement patterns.
3. The two smaller turtles ranged widely beyond the bay. One of these (69.5 cm curved‐carapace length; CCL) used the coldest region of the Mediterranean during the first winter of tracking where mean weekly temperatures dipped below 12°C but moved southwards to warmer waters during the second winter. In comparison, the other (66 cm CCL) individual moved south to winter in warmer waters from the outset. Both individuals returned to Drini Bay during summer, demonstrating fidelity to the study site. The third turtle, which was larger (76 cm CCL), remained in Drini Bay for the duration of tracking. These results support the findings of other mark–recapture studies at Drini Bay, which have suggested that the foraging site is being used in a transient way by immature turtles.
4. All three turtles preferentially used the shallow waters (<30 m) in the south of Drini Bay. The study demonstrates a high degree of overlap between the habitat use of the three tracked turtles and that of adult turtles tracked from nesting sites, and although based on a small sample size, contributes to a growing knowledge base regarding the wider habitat use of the Mediterranean loggerhead population.

     

Creating space for sustainable food systems: Lessons from the field

In response to growing trendsin the current food system toward globalintegration, economic consolidation, andenvironmental degradation, communities haveinitiated alternative, more sustainable foodand agricultural systems. Lessons may now belearned about the development and maintenanceof local, sustainable food systems projects –those that attempt to integrate theenvironmental, economic, and social health oftheir food systems in particular places. Fourkinds of space need to be created and protected– social space, political space, intellectualspace, and economic space. Three importantthemes emerge from these community spaces:public participation, new partnerships, and acommitment to social, economic, andenvironmental justice principles.     

Risk of human immunodeficiency virus (HIV-1) infection among laboratory workers

In a prospective cohort study of 265 laboratory and affiliated workers, one individual with no recognized risk factors for human immunodeficiency virus type 1 (HIV-1) infection was HIV-1 seropositive at the time of entry into the study. Molecular analyses of two HIV-1 isolates derived in two independent laboratories from a blood sample from this worker showed that the isolates were indistinguishable from a genotypic form of HIV-1 present in the H9/HTLV-IIIB cell line. Exposure to this strain of virus most probably occurred during work with concentrated virus or culture fluids from virus-producing cell lines under standard Biosafety Level 3 containment. Although no specific incident leading to this infection has been identified, undetected skin contact with virus culture supernatant might have occurred. This worker was the only one found to be positive among the subgroup of 99 workers who shared a work environment involving exposure to concentrated virus. The incidence rate of 0.48 per 100 person-years exposure indicates that prolonged laboratory exposure to concentrated virus is associated with some risk of HIV-1 infection, which is comparable to the risk for health care workers experiencing a needle stick exposure. While none of the ten workers with parenteral exposure to HIV-1 in this cohort became infected, a worker in another laboratory did seroconvert following an injury with a potentially contaminated needle. Strict Biosafety Level 3 containment and practices should be followed when working with concentrated HIV-1 preparations, and further refinement of the procedures may be necessary.     

Development of a novel diagnostic test for detection of bovine viral diarrhea persistently infected animals using hair

The purpose of this study was to determine whether manually plucked hairs might serve as an alternative sample for a quantitative real time polymerase chain reaction (qRT-PCR) testing. Twenty three, 1~3 week old, non-bovine viral diarrhea virus (BVDV) vaccinated calves, found to be positive for BVDV by immunohistochemical staining, were selected and hairs were manually plucked from the ear. qRT-PCR was performed on samples consisting of more than 30 hairs (30~100) and whole blood. All 23 animals were positive for the virus by qRT-PCR performed on the whole blood and when samples of more than 30 hairs were assayed. Additionally, qRT-PCR was performed on groups of 10 and 20 hairs harvested from 7 out of 23 immunohistochemical staining-positive calves. When groups of 20 and 10 hairs were tested, 6 and 4 animals, respectively, were positive for the virus.     

FTIR-ATR-based prediction and modelling of lignin and energy contents reveals independent intra-specific variation of these traits in bioenergy poplars

Background  

There is an increasing demand for renewable resources to replace fossil fuels. However, different applications such as the production of secondary biofuels or combustion for energy production require different wood properties. Therefore, high-throughput methods are needed for rapid screening of wood in large scale samples, e.g., to evaluate the outcome of tree breeding or genetic engineering. In this study, we investigated the intra-specific variability of lignin and energy contents in extractive-free wood of hybrid poplar progenies (Populus trichocarpa × deltoides) and tested if the range was sufficient for the development of quantitative prediction models based on Fourier transform infrared spectroscopy (FTIR). Since lignin is a major energy-bearing compound, we expected that the energy content of wood would be positively correlated with the lignin content.     

Onondaga Lake and the dynamics of chloride in the Oswego River

The temporal distribution of chloride concentration in the Oswego River was determined at 6 hr intervals for a 3 mo period during the summer of 1982. The dynamics of relative flow and chloride contributions from the three major sources forming the Oswego River, and the dynamics of flow releases from one of the sources, chloride-polluted Onondaga Lake, were determined from the above measurements, available chloride concentrations, and flow data for the system, through application of a simple mass balance on chloride. The chloride concentration and load in the Oswego River were found to be highly variable with time, and largely due to the dynamics of flow release from Onondaga Lake. The chloride distribution in the Oswego River, with its unique dynamics and chemically conservative nature, make it a valuable hydraulic tracer for the system.