Growth, carcass and meat quality traits of straightbred and crossbred Botucatu rabbits

The objective was to evaluate the effects of genetic group and age on growth, carcass, and meat traits of rabbits. A total of 144 straightbred Botucatu and White German Giant x Botucatu crossbred rabbits were involved. Rabbits were weaned at 35 d and sequentially, slaughtered, four per genetic group x sex combination, at: 42, 49, 56, 63, 70, 77, 84 and 91 d. A 2x2 factorial arrangement was employed in a completely randomized design with repeated measures for growth traits, and a split-plot for carcass and meat traits. Crossbred rabbits were heavier (2032 vs. 1962 g; P < 0.01), consumed more feed (143.5 vs. 131.0 g/d; P < 0.01), and presented higher slaughter weight (2169 vs. 2093 g, P=0.02) and dressing percentage (59.0 vs. 58.2%; P=0.07) than straightbreds throughout the experiment. No difference between genetic groups was detected for feed conversion and empty gastrointestinal weight corrected for slaughter weight (SW). Crossbreds showed higher skin weight (308.2 vs. 299.7 g, P = 0.06) and distal parts of leg weight (75.7 vs. 71.4 g; P < 0.01), both corrected for SW. No genetic group effect was detected on dissectible fat and hind part weights. Chilled commercial carcass (1284 vs. 1229 g: P=0.02), chilled reference carcass (1036 vs. 1000 g, P=0.06), fore part (297.9 vs. 283.3 g; P=0.01) and loin (308.7 vs. 295.5 g; P=0.05) were heavier in crossbreds than in straightbreds, but these differences were attributed to differences in SW. Uncorrected weights of head, kidneys, liver and thoracic viscera were higher in the crossbred group, but only head (116.6 vs. 113.6 g; P=0.06) and thoracic viscera (30.4 vs. 28.6 g; P=0.01) were, in fact, proportionately heavier in crossbreds than in straightbreds. No effect of genetic group was detected on meat to bone ratio, muscle ultimate pH and chemical composition of the Longissimus dorsi muscle. All traits, except for ash and fat contents of the Longissimus muscle, showed age effects (P < 0.01). Crossbreeding may be recommended for the production of whole commercial carcasses, but it is not clearly advantageous for the production of retail cuts. Slaughter should take place between 63 and 70 d of age for both genetic groups.

Evidence of Chlamydophila psittaci infection in captive Amazon parrots in Brazil

The prevalence of Chlamydophila psittaci (formerly Chlamydia psittaci) infection was assessed in 95 apparently healthy, captive Amazon parrots from three breeder collections in southeastern and west-central Brazil. Cloacal swabs from 95 birds were tested for chlamydial antigen, which was detected by direct immunofluorescence (DIF), and serum samples from 44 of these birds were tested for antibodies to C. psittaci using an enzyme-linked immunosorbent assay. The prevalences of active infection as detected by DIF were 16.7%, 22.2%, and 56.1%, and seroprevalences were 100%, 87.5%, and 60% in flocks A, B, and C, respectively. We can therefore infer that C. psittaci may be widespread in captive parrot populations in Brazil.

A note on carcass characteristics of rabbits fed on a restricted system

Thirty four 65 days old New Zealand White female rabbits. weighting 1900 +/- 40 g, were separated in 3 groups and caged individually. One group was slaughtered when 70 days old (reference group, n=14). The second group was slaughtered 50 days later after ad libitum feeding (n = 6), and the third group was slaughtered also when 120 days old, but after restricted feeding since 70 days old i.e. 50% of the spontaneous feed intake of the 65-70 days period (restricted group n=14). Whole carcass weight and carcass cuts weights were measured after 24 hours storage at +4 degrees C. For each of the 3 groups in the previous order, slaughter live weight was 1992 - 2988 and 1887g; Chilled carcass percentage were 47.9 - 51.0 and 50.1. Feed restriction decreased the loin proportion of the carcass lower than that of the reference group (27.0 - 26.1 and 22.8% for the 3 groups in the same order) but increased the posterior limbs proportion (36.5 - 36.6 and 40.1).

CELL-MEDIATED AND HUMORAL IMMUNE-RESPONSES IN IMMUNIZED AND OR DERMATOBIA-HOMINIS INFESTED RABBITS

The cell-mediated and humoral immune response of rabbits to antigens from larvae of Dermatobia hominis were analyzed by leucocyte migration inhibition factor assay (MIF), immunodiffusion (ID) and passive hemagglutination (PH) test in rabbits immunized with D. hominis extract, in rabbits immunized and infested with the parasite and rabbits infested with D. hominis. Twenty rabbits were divided into five groups: Group 1, rabbits immunized with a crude antigen extract, evaluated for 40 weeks at 4 week intervals; Group 2, rabbits immunized and infested with newly hatched larvae at 14 weeks post immunization (PI) and evaluated as Group 1; Group 3, rabbits immunized, evaluated for 28 weeks at 2 week intervals; Group 4, rabbits immunized and infested at 4 weeks PI and evaluated as Group 3; Group 5, rabbits infested and evaluated for 24 weeks at 2 week intervals. Different patterns of reactivity were observed in the infested and immunized animals: immunized rabbits developed antibodies and cellular immune responses earlier and at higher levels during immunization than the infested rabbits; the infestation at 14 weeks PI, when the cell-mediated and humoral immune response began to decrease, or at 4 weeks PI when these parameters were at higher levels, elicited an anamnestic response. After the spontaneous elimination of larvae by the host, from the 4th week PI onwards, high titers of antibodies and migration inhibition indices were maintained for a long period. These results suggest that the onset of cellular and humoral immune responses after immunization may be important as a biological control of myiasis and contribute to better understanding of the immune defense mechanism of the host against D. hominis.

Anxiety levels and wild running susceptibility in rats: assessment with elevated plus maze test and predator odor exposure

It is reported in the literature that nearly 20% of rats are susceptible to displays of wild running (WR) behavior when submitted to high intensity acoustic stimulation. Some characteristics of WR suggest that it can be viewed as a panic-like reaction. This work aimed to test whether WR-sensitive rats show higher levels of anxiety in elevated-plus-maze (EPM) and predator-odor exposure paradigms in comparison with WR-resistant ones. Male adult Wistar rats were submitted to two trials of acoustic stimulation (104 dB, 60 s) in order to assess WR susceptibility. Seven WR-sensitive and 15 WR-resistant rats were evaluated by the EPM test. Other 13 WR-sensitive and 18 WR-resistant animals were submitted to the predator-odor exposure test which consisted of a 10 min-session of free exploration in a specific apparatus containing two odoriferous stimuli: cotton swab imbedded with snake cloacal gland secretion or with iguana feces (control). WR-sensitive rats presented a significantly higher closed-to open-ann-entry ratio in the EPM test. All rats responded with anxiety-like behaviors to the predator odor exposure, although the WR-sensitive ones showed a marked behavioral inhibition regardless of the odor condition. We conclude that WR-sensitive rats present elevated levels of anxiety manifested by means of passive behavioral strategies. (C) 2004 Elsevier B.V. All rights reserved.

Net energy, protein and macrominerals requirements for 70 to 120 day old female rabbits

In order to determine the net energy, protein and macrominerals requirements of 70 to 120 day old, 52 female White New Zealand rabbits, weighing 1900g +/- 40g were used. At the beginning of the experimental period, 14 of the 52 young does were slaughtered and the 38 remaining animals were kept under two dietary management: ad libitum and restricted feeding. Slaughters were performed to determine each nutrient body content. The weight gain nutrient requirements depicted by the quantities of each nutrient stored into the body were obtained by applying the regression equation, which estimate the empty body nutrient content logarithm as a function of the empty body weight logarithm, as described by ARC (1980). By determining the heat production logarithm at the zero level of metabolizable energy intake, the maintenance net energy requirement was estimated to be 45.31 Kcal/day/Kg(0.75) the mean net energy. protein, calcium, phosphorous, sodium, magnesium and potassium requirements for each gram of weight gain per day were estimated to be, 2.51 Kcal, 0.21g, 0.02g, 0.005g, 0.001g, 0.0004g and 0.002g, respectively.

Species diversity and seasonality of free-living ticks (Acari : Ixodidae) in the natural habitat of wild Marsh deer (Blastocerus dichotomus) in Southeastern Brazil

This study evaluated the presence and seasonal activity of free-living ticks in remaining marsh areas by the Parana river, in Brazil. Eight field trips (once per season) for collection of ticks were performed during 2 years. Using CO2 traps, dragging, and visual inspection of vegetation, five free-living tick species were collected, in the following order of abundance: Amblyomma cajennense, Amblyom\ma dubitatum, Amblyomma triste, Amblyomma coelebs, and Amblyomma nodosum. The seasonal pattern of A. cajennense was characterized by the highest peaks for adult ticks in the summer/spring months, for nymphs in the winter and for larvae in the autumn and winter. A. dubitatum and A. triste presented similar seasonal patterns characterized by peaks of adult ticks in the autumn. Nymphs of A. dubitatum peaked in the winter of the first year and in the winter/spring of the second year. A. triste was the only species to be collected in significantly higher numbers in the marsh than in surrounding drier areas such as forest patches. Among domestic animals living close the marsh areas, horses were infested by Anocentor nitens, A. cajennense, and Boophilus microplus, bovines were infested solely by B. microplus, and dogs were infested by Rhipicephalus sanguineus. Adults of A. triste showed to be well adapted to the marsh environment. This result, at least partially, explains local previous observations on the association of A. triste with marsh deer, as this vertebrate host inhabits mainly the marsh area. (c) 2006 Published by Elsevier B.V.

COMPARATIVE STUDIES ON PIGMENT GRANULES AND PIGMENT DISTRIBUTION IN THE COMPOUND EYES OF WILD-TYPE AND MUTANT WORKER HONEYBEES .2. AN ULTRASTRUCTURAL ANALYSIS

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Hepatozoon canis infection of wild carnivores in Brazil

Hepatozoon canis was diagnosed in a crab-eating fox (Cerdocyon thous) found on a highway in the region of Botucatu, São Paulo, Brazil, after being hit by a car. The fox had bilateral fractures of the olecranon, which was corrected by osteosynthesis. Hematologic findings included a neutrophilia, eosinophilia, monocytosis and mild anemia. In the Leishman-stained blood film, gametocytes of Hepatozoon canis in neutrophils were identified measuring 9.1+/-0.54x5.3+/-0.46 mu m. (C) 1997 Elsevier B.V. B.V.

MOLECULAR DIAGNOSIS of LEISHMANIA AMAZONENSIS IN A CAPTIVE SPIDER MONKEY IN BAURU, São Paulo, BRAZIL

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Morphology of Aortic Arch in Rabbits with Atherosclerosis Treated with Resveratrol

Objective: Atherosclerosis is a chronic inflammatory condition associated with the production of oxidative species. The phenoliccompound, resveratrol, seems to have cardioprotective activities preventing the oxidation of low-density lipoproteins.In this study we investigated the effect of resveratrol on prevention of induced atheromatosis, through the morphological study of the segment of aortic arch in White New Zealand rabbits.Study design: 20 rabbits were divided into four groups which received the following diet for 60 days: control group (CT) normal ration; resveratrol group (R) normal ration and resveratrol (3 mg/kg/day); cholesterol group (CL) 1.5% of cholesterol added to the ration; group cholesterol plus resveratrol (CR) 1.5% of cholesterol added to the ration and resveratrol (3 mg/kg/day). The analysis of the atherosclerotic lesions were performed by the means of appropriate histological techniques.Results and conclusions: The animals belonging to group CL showed atherosclerotic lesions with tunica intima thickening due to the presence of foam cells, placed in several disorganized layers, and extracellular lipid droplets in subendothelial conjunctive tissue.We also observed the invasion of foam cells in the beginning of tunica media. In animals belonging to group CR there were changes in the subendothelial of tunica intima, although in a minor degree of development as for the number of foam cells layers and extracellular lipid droplets. An invasion of foam cells in tunica media was observed in this group. We haven't seen any changes in tunica adventitia in any of the studied groups. There were not evident histological changes in any of the analised tunicas for groups CT and RConclusions: This study may help demonstrate that the phenolic compound, resveratrol, works as a preventive agent in the development of atherosclerotic lesions.