Dietary methionine deficiency reduces laying performances of female common ducks and impacts traits of interest of their mule ducklings.

The effects of maternal nutrition on offspring phenotypes have been mainly documented over the past years in mammals, and are now studied in poultry as well. In the present study, we investigated the effects of a reduced level of dietary Methionine (Met) on laying performances of common laying ducks and their impacts on the phenotype of their mule ducklings. A total of 60 female laying ducks were divided into 2 dietary treatments at 10 wk of age. The restricted group received Met-restricted diets (R group) containing 0.25% of Met whereas the control group received control diets (C group) containing 0.40% of Met that meets Met requirements. The restriction was applied during the growing and laying periods, from 10 to 51 wk of age and a particular focus was put on female breeder traits that might be affected by the Met restriction. Plasma parameters of hepatic and lipid metabolisms were recorded in ducklings. Total weight (P < 0.001), albumen weight (P < 0.001) and albumen percentage of dry matter (P < 0.01) were decreased for eggs laid by female breeders from the R group. Both male and female ducklings from the R group of female breeders showed a reduced BW at hatching (P < 0.001) and a tendency to an increased proportional liver weight (P = 0.07). Finally, the maternal low dietary Met level modified plasma parameters in newborn ducklings regardless of sex: alkaline phosphatase (ALP) and alanine transaminase (ALT) activities were reduced (P = 0.07 and P = 0.002, respectively), levels of glucose (P = 0.03) and triglycerides (P = 0.01) were higher whereas level of free fatty acids decreased (P = 0.01). It was concluded that feeding female laying ducks with a restricted dietary Met content during the growing and laying periods has a negative effect on egg weight and composition. The ducklings that were restricted in nutrients during their early development, have a reduced BW, and altered lipid and hepatic metabolisms.

A kinetic study of the natural induction of liver steatosis in Greylag Landaise geese: the role of hyperphagia.

We have previously demonstrated that a sharp rise in feed intake (hyperphagia) and spontaneous liver steatosis could be experimentally induced in domestic Greylag geese by combining a short photoperiod and a sequence of feed restriction followed by ad libitum corn feeding during the fall and the winter. In this previous work, however, individual feed intake could not be recorded. The present study aimed at evaluating the relationship between level and pattern of hyperphagia and liver weight with an individual control of feed intake in individually housed (IH) geese, while comparing the performances with group housed (GH) geese. A total of 300 male geese of 19 weeks of age, were provided with corn ad libitum after an initial feed restriction period. From 21 to 23 weeks of age, the daylight duration was progressively reduced from 10 to 7 h and kept as such until the end of the experiment (week 36). In all, 30 GH and 30 IH geese were slaughtered at 19, 27, 30, 32 and 36 weeks of age. Feed intake was measured per group in GH geese and individually in IH geese. During the 1st week of corn feeding, the average feed intake rose up to 600 g/goose per day in GH geese but not in IH geese where the feed intake rose gradually from 300 to 400 g/day. The liver weight increased from 93 g (week 19) to 497 g (week 32; P<0.05) in GH birds. In IH birds, liver weights were, on average, much lower (ranging from 220 to 268 g) than in GH birds (P<0.05). In GH and IH bird, the variability in the individual response to corn feeding was very high (liver weight cv ranging from 63% to 83% depending on slaughter age). A close correlation between corn consumption and liver weight was evidenced in IH birds at each slaughter age (R 2 ranging from 0.62 to 0.79), except at 36 weeks of age where this correlation was weak (R 2=0.14). The variability in the extent of liver steatosis is very high and our results in IH birds clearly point out the major role of hyperphagia, mainly at the beginning of the ad libitum corn feeding period, on the development of spontaneous liver steatosis.

A morphological study of 608 cases of canine malignant lymphoma in France with a focus on comparative similarities between canine and human lymphoma morphology.

This study reports cytomorphological, histomorphological, and immunological characterization of 608 biopsy cases of canine malignant lymphoma, with epidemiological and clinical data, collected from 7 French veterinary pathology laboratories. It compares morphological characteristics of malignant lymphoma in canines, per the updated Kiel classification system, with those reported in humans, per the World Health Organization (WHO) classification system. Of tumors described, 24.5% and 75.5% were classified as low- and high-grade malignant lymphomas, respectively. Presenting clinical signs included generalized or localized lymphadenopathy (82.4%) and extranodal diseases (17.6%) involving the skin (12.34%) and other sites (5.26%). Immunohistochemistry confirmed 63.8% B-cell (CD3-, CD79a+), 35.4% T-cell (CD3+, CD79a-), and 0.8% null-cell (CD3-, CD79a-) lymphomas. Most B-cell cases (38.49%) were of high-grade centroblastic polymorphic subtype; most T-cell cases (8.55%), high-grade pleomorphic mixed and large T-cell lymphoma subtypes. Some B-cell tumors showed morphologic characteristics consistent with follicular lymphomas and marginal zone lymphomas per the Revised European American Classification of Lymphoid Neoplasms and WHO canine classification systems and the WHO human classification system. Unusual high-grade B-cell subtypes included an atypical high-grade small B-cell lymphoma (0.66%), Burkitt-type B-cell lymphoma (1.64%), plasmacytoid lymphoma (0.99%), and mediastinal anaplastic large B-cell lymphoma (0.16%). Unusual T-cell subtypes included a previously undescribed high-grade canine immunoblastic T-cell type (1.15%), a rare low-grade prolymphocytic T-cell lymphoma (0.16%), and a recently described high-grade canine T-cell entity--aggressive granulocytic large-cell lymphoma (0.16%). Marginal zone lymphomas were common (10.86%); follicular lymphomas were rare (0.49%). Canine primary cutaneous malignant lymphoma subtypes were present (11.84%). There was no significant difference between B- and T-cell malignant lymphoma in regard to canine age and sex. A significant overrepresentation of Boxers (24.19%) was found for T-cell lymphomas.

Effects of varying proportions of concentrates on ruminal-reducing power and bacterial community structure in dry dairy cows fed hay-based diets.

The objectives of this study were to evaluate the influence of diet composition on ruminal parameters, more particularly redox potential (Eh). Four Holstein dry dairy cows, fitted with ruminal cannulas, were allocated in a 4 × 4 Latin square design. They were given four experimental hay-based diets D0, D25, D42 and D56 consisting of 0%, 25%, 42% and 56% of ground wheat and barley concentrate mixture, respectively. They were fed at a daily feeding rate of 8.0 kg DM per cow during a 24-day experimental period (a 21-day diet adaptation, three consecutive days of measurement and sampling). The physicochemical parameters, such as pH and Eh, were measured and Clark's exponent (rH) was calculated from 1 h before feeding to 8 h after feeding at 1-h interval. Samples of ruminal fluid were taken at 0, 1, 2, 4, 6 and 8 h after feeding for the determination of volatile fatty acid (VFA) and ammonia N (NH3-N) concentrations. Ruminal bacterial populations were also studied by means of capillary electrophoresis single-strand conformation polymorphism (CE-SSCP) technique to focus on the structure of the ruminal microbiota and the diversity index was calculated. Mean ruminal Eh and rH were not modified by the concentrate-to-forage ratio and averaged - 210 mV and 6.30, respectively, across diets. The pH decreased slightly by 0.10 pH unit between treatments D0 and D56 with an average of 6.58. Nevertheless, the time during which physicochemical parameters remained at nadir value after feeding varied with diets: 2 and 7 h for D0 and 6 and 5 h for D56, respectively for pH and Eh. Moreover, fermentative parameters were altered by treatments: total VFA and NH3-N were greater in D56 (72.2 mM and 17.5 mg/100 ml) compared with D0 (65.2 mM and 14.2 mg/100 ml). However, neither the structure of bacterial populations of the rumen nor the diversity index (Shannon) was altered by treatments.

High-grade canine T-cell lymphoma/leukemia with plasmacytoid morphology: a clinical pathological study of nine cases.

The aim of this study is to determine the clinical, morphological, and immunophenotypical presentation of 9 cases of a particular type of canine T-cell lymphoma/leukemia. The morphological presentation was a diffuse infiltration of small, medium-sized, or large blast cells with eccentric nuclei, hyperbasophilic cytoplasm, and a juxtanuclear, pale cytoplasmic area, giving a plasmacytoid appearance and suggesting a B-cell morphology. Surprisingly, all 9 cases were of T-cell phenotype (CD3+). Among the 7 immunophenotyped cases, 4 were CD4-/CD8+, 2 CD8+/CD4+, and 1 CD4+/CD8-. The median Ki-67 index was 65.7%, which placed this lymphoma in the high-grade group. This type of lymphoma/leukemia was found in dogs between 1 and 11 years of age, with a median age of 5.8. The male-female ratio was 0.8 for a reference population of 1.04. The most significant clinical findings were lymphadenopathy either generalized or localized in all cases, a mediastinal mass in 4 cases, bone marrow involvement in 7 cases, hypercalcemia in 4 cases, along with an aggressive clinical course and a poor response to chemotherapy in all cases, with a median disease-free survival time of 3 months.

Canine T-cell lymphomas: a morphological, immunological, and clinical study of 46 new cases.

The aim of this study is to report 46 new cases of canine T-cell lymphomas among a series of 140 lymphomas studied by immunophenotyping (incidence 32.8%). According to the updated Kiel classification adapted to the canine species, 13 were classified as low-grade and 33 as high-grade lymphomas. Among the low-grade lymphomas, five were small clear-cell lymphomas, three were pleomorphic small-cell lymphomas, and five mycosis fungoides. Among the high-grade cases, there were 11 pleomorphic mixed-, small-, and large-cell lymphomas, 6 pleomorphic large-cell lymphomas, 11 lymphoblastic lymphomas, and 5 unclassifiable high-grade plasmacytoid lymphomas. The cytohistologic features were highly suggestive of a T-cell phenotype on the basis of cell morphology (irregular nuclei and clear cytoplasms) (30/46 cases), a T-cell zone pattern, and the presence of hyperplastic postcapillary venules (22/46 cases). All 46 cases were CD3+ CD79a-, and among 34 cases investigated for CD4 and CD8 expression, 13 were CD4+CD8-, 13 were CD8+CD4-, and 8 were CD4CD8 double positive or double negative. The pleomorphic mixed lymphomas were mainly CD4+CD8- (6/7) and the lymphoblastic lymphomas were double positive or double negative (6/8). The main clinical, hematologic, and biochemical features were generalized (28/46) or regional lymphadenopathy (16/46), hepatosplenomegaly (15/46), extranodal involvement (11/46), mediastinal mass (9/46), and leukemia (8/46), which were mainly present in cases of lymphoblastic lymphomas and hypercalcemia (16/46).

Clinical applications of flow cytometry and cell immunophenotyping to companion animals (dog and cat).

Clinical applications of flow cytometry to certain diseases of the dog and cat are now possible. The utility of such applications for diagnosis, prognosis and follow-up are illustrated here by a number of examples: feline AIDS resulting from FIV infection, Leukocyte Adhesion Deficiency in Irish setters, deep pyoderma in German shepherds, Immune-mediated Thrombocytopenia, canine Systemic Lupus Erythematosus and Leishmaniasis, Leukemia and Lymphoma.

Characterization of a canine long-term T cell line (DLC 01) established from a dog with Sézary syndrome and producing retroviral particles.

The canine DLC 01 cell line derives from a lymph node of a dog with Sézary syndrome. The DLC 01 cell phenotype is CD4-, CD8+, CD45+, DQ+, similar to that of original cells after treatment with dimethylsulfoxide or phorbol myristate. Canine cutaneous T cell lymphoma are usually CD4-, CD8+ in contrast to their human counterparts which are CD4+, CD8-. Therefore, the DLC 01 cell line appears to be a unique model to study the mechanism of all surface molecule expression in vitro. Viral particles with retrovirus type-C morphology were found in ultrathin sections of DLC 01 cell pellets. Retroviral particles are spontaneously produced after the 50th cell passage or after induction with 0.5% dimethylsulfoxide. This is the first description of a dog lymphoid cell line spontaneously growing and producing a retrovirus. It was found to share several features in common with feline and murine leukemia viruses.

Lymphocyte subset abnormalities in canine leishmaniasis.

Peripheral blood lymphocyte subpopulations were studied in 42 Leishmania infantum-infected dogs using flow cytometry. Twenty-two healthy dogs were used as a control group. Analysis of the B-cell populations showed a reduction in the number of CD21+ cells in all the infected dogs. On the other hand, the disease was found to be associated with a striking decrease in the number of CD21+ cells and of T-lymphocyte CD4+ cells in comparison with asymptomatic dogs and with healthy dogs. This study suggests that the dysimmunity which is observed with leishmaniasis may be linked to a reduced number of T-lymphocyte CD4+ cells.

Specific IgG1 and IgG2 antibody and lymphocyte subset levels in naturally Leishmania infantum-infected treated and untreated dogs.

Peripheral blood lymphocyte subpopulations and specific IgG1 and IgG2 antibody levels were studied in 14 dogs naturally infected with Leishmania infantum using flow cytometry and ELISA. Six dogs (Group 1) were asymptomatic, and received no treatment. Samples from this group were collected from D0 to D180. The other eight dogs (Group 2) showed clinical symptoms, and were treated with Glucantime (from D0 to D40), with samples being collected from D0 to D90. Twenty-two healthy dogs were used as a control group (Group 3). The results demonstrated changes in the lymphocyte subsets, as well as a decrease in humoral and cellular immunity, in the infected dogs. Analysis of the B-cell populations of Groups 1 and 2 showed a striking reduction in the number of CD21+ cells. There was also a reduction in the CD5+, CD4+ and CD8+ T-cell populations. Drug therapy was found to partly restore the lost immunity, essentially the cell-mediated immunity. Both IgG1- and IgG2- specific antibodies were detected in sera from the fourteen infected dogs, but the IgG2 subclass appeared to be predominant. A significant decrease in the level of IgG2 antibodies was observed in treated and untreated dogs.