Locomotion problems of broiler chickens and its relationship with the gait score

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

Jejum Pré-abate em Frangos de Corte

As condições ideais dos frangos de corte no momento do abate devem ser conhecidas a fim de possibilitar a produção de carne de excelente qualidade, uma vez que diversos fatores pré e pós-abate estão envolvidos na qualidade final. em condições normais de abate e processamento, a retirada de ração é feita de 6 a 8 horas antes da apanha das aves, resultando em um período total de jejum de 8 a 12 horas antes do abate, para esvaziar o intestino e com isso minimizar a contaminação no abatedouro. A escalda, depena e evisceração são pontos importantes de contaminação cruzada no abatedouro devido à grande quantidade de microorganismos aderidos às penas, pele e patas das aves e ao rompimento das vísceras durante a evisceração. Entretanto, a desidratação da carcaça começa imediatamente após o início do jejum. Períodos prolongados de jejum podem afetar o pH das diversas partes do intestino, aumentando a presença de Salmonella e outros microorganismos patogênicos. Além disso, determinam uma maior contaminação pela bile, e são, subjetivamente, associados à fragilidade dos intestinos durante a evisceração mecânica. Portanto, os esquemas de processamento devem ser estabelecidos levando-se em conta a integridade e o esvaziamento do intestino e da vesícula biliar, bem como a desidratação e os seus efeitos sobre o bem estar das aves, contaminação da carcaça e qualidade da carne. Como alguns efeitos do jejum ainda não são bem conhecidos, sugerem-se pesquisas nas seguintes áreas: definir o tempo ótimo de jejum para atender o bem estar das aves, minimizar a contaminação e otimizar os parâmetros de qualidade de carcaça; estudar os efeitos de períodos prolongados de jejum sobre o pH e a colonização do papo, pró-ventrículo, moela, intestino delgado, intestino grosso e cecos por enterobactérias, como Salmonella, por exemplo; efeito do jejum sobre o tamanho e cor do fígado. O resultado esperado é um aumento na qualidade final dos produtos aliado a uma redução nas perdas e no custo de produção.

The relationship between dairy cow hygiene and somatic cell count in milk

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

Morpho-physical Recording of Bovine Conceptus (Bos indicus) and Placenta from Days 20 to 70 of Pregnancy

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

Anesthesia of fish with benzocaine does not interfere with comet assay results

Fish blood erythrocytes are frequently used as sentinels in biomonitoring studies. Usually, fish blood is collected by painful cardiac or caudal vein punctures. Previous anesthesia could decrease animal suffering but it is not known at present whether anesthesia can cause confounding effects. Therefore, using the alkaline single cell gel (SCG)/comet assay with blood erythrocytes of the cichlid fish Nile tilapia, we tested for a possible modulation of induced DNA damage (methyl methanesulfonate; MMS) by the anesthetic benzocaine administered by bath exposure (80mg/l for ∼10min). Furthermore, benzocaine (80-600mg/l) was tested for its genotoxic potential on fish erythrocytes in vitro and for potential interactions with two known genotoxins (MMS and hydrogen peroxide). Our results did neither indicate a significant increase in the amount of DNA damage (even after a 48h follow-up), nor indicated interactions with MMS-induced DNA damage when fish were exposed to benzocaine in vivo. There was also no increase in DNA damage after in vitro exposure of fish erythrocytes to benzocaine. Clear concentration-related effects were observed for the two genotoxins in vitro, which were not significantly altered by the presence of benzocaine. These results suggest that anesthesia of fish does not confound comet assay results and the use of blood samples from anesthetized fish can be recommended with regard to animal welfare. © 2002 Elsevier Science B.V. All rights reserved.

Avaliação de diferentes híbridos suínos submetidos à insensibilização elétrica e gasosa (CO 2). Parte 3 - Mensurações visuais de qualidade

Three pig genetics lineages A, B and C marketed in Brazil, were stunning with the manual electric stunning (Karl Schermer 220-230/250 volts, 45-60 Hz and 1.4 - 1.5 A) and the collective gaseous system (COMBI-BUTINA 90% CO 2). The electric stunning provided higher blood splashed levels in the areas of the inside round (0.477 and 0.26, p ≤ 0.01), shoulder/cranial (0.154 and 0.039, p ≤ 0.005), shoulder/central (0.261 e 0.052, p ≤ 0.001), shoulder/caudal (0.180 and 0.030, p ≤ 0.01), loin/central (0.185 and 0.065, p ≤ 0.01), loin/caudal (0.06 and 0.207, p ≤ 0.01) and loin/lateral external (0.061 and 0.013, p ≤ 0.05), as well as more diffuse blood splashed in the areas of the inside round (0.461 and 0.279, p ≤ 0.05), shoulder/cranial (0.154 and 0.039, p ≤ 0.001), shoulder/central (0.231 and 0.039, p ≤ 0.001) and shoulder/caudal (0.185 and 0.026, p ≤ 0.001). The electric stunning also provided higher skin damage levels in the areas of the shoulder (1.098 and 0.795, p ≤ 0.001), body (1.04 and 0.948, p ≤ 0.05) and ham (0.84 and 0.68, p ≤ 0.001), as well as higher eyelid reflex levels (11.57%) comparatively to the gaseous system (2.86%) of a total of 426 pigs. Small indexes of bone fractures and muscle bruises were found in both systems.

A place preference test in the fish Nile tilapia

The Nile tilapia fish (Oreochromis niloticus) has a high potential to be used as a model in neuroscience studies. In the present study, the preference of the Nile tilapia between a gravel-enriched (GEE), a shelter-enriched (SEE) or a non-enriched (NEE) environment was determined, for developing a place preference model. Nile tilapia had an initial preference for GEE, but after 1 day of observation, the fish stabilized their frequency of visits among compartments. Hence, any stimulus motivating tilapia increase in compartment visiting indicates a positively reinforcing effect. This feature is very useful for the development of new behavioural paradigms for fish in tests using environmental discrimination, such as the conditioning place preference test. © 2006 Elsevier GmbH. All rights reserved.

Ventilatory frequency of Nile tilapia subjected to different stressors

Ventilatory frequency (VF) was investigated in the fish Nile tilapia, Oreochromis niloticus, subjected to confinement, electroshock or social stressor. Fish were allowed to acclimatize to tank conditions for 10 days (1 fish/aquarium). VF baseline was determined 5 days after adjustment had been started. At the 10th day of isolation, stressor effects on VF were assessed. The stressors were imposed during 60 min: pairing with a larger resident animal (social stressor), or gentle electroshock (AC, 20 V, 15 mA, 100 Hz for 1 min every 4 min), or space restriction (confinement). VF was quantified immediately after the end of the stressor imposition. Baseline of VF was not statistically different among groups. Social stressor clearly induced VF to increase, while an increased or decreased VF can be observed for both confinement and electroshock. However, fish tend to increase their VF in response to confinement and decrease in the case of electroshock. These results suggest that VF is a sensitive behavioural indicator for distinguishing stress responses in the fish Nile tilapia among different stressors. © 2006 Elsevier GmbH. All rights reserved.

Medium-term tongue carcinogenesis assays: A comparative study between 4-nitroquinoline 1-oxide (4NQO)-induced rat and dimethylbenzanthracene (DMBA)-induced hamster carcinogenesis

The most used animal models in oral cancer research are the hamster treated by dimethylbenzanthracene (DMBA), and the rat treated by 4-nitroquinoline 1-oxide (4NQO). The purpose of this study was to compare the DMBA-induced hamster tongue carcinogenesis and 4NQO-induced rat tongue carcinogenesis by means of morphological analysis. Male Wistar rats were distributed into three groups of ten animals each and treated with 50 ppm 4NQO solution by drinking water for 4, 12 or 20 weeks. A total of 18 Syrian golden hamsters were submitted to 0.5% DMBA (dissolved in acetone) topical application three times/week for 4, 12 and 20 weeks. The primary histopathological change i.e., hyperplasia and hyperkeratosis, was evidenced after 4 weeks treatment with DMBA. Regarding 12 weeks treatment, 4NQO and DMBA were able to induce morphological changes as depicted by hyperplasia and dysplasia. At 20 weeks, squamous cell carcinoma was found in the majority of animals for both carcinogens used. Taken together, our results suggest that the hamster experimental model disclosed aspects related with tongue carcinogenesis in lesser time than rats. Probably, such discrepancies depend strongly on route of administration and the susceptibility with respect to animal species. © 2006 Elsevier GmbH. All rights reserved.

Biological aspects of Amblyomma brasiliense (Acari: Ixodidae) under laboratory conditions

Although Amblyomma brasiliense Aragão 1908 has been reported as one of the most aggressive ticks to humans in Brazil, information about the biology of this tick species is virtually inexistent. This work reports data on the life cycle of A. brasiliense fed on rabbits and pigs and maintained in an incubator at 20°C, 90% RH and 12 h of light for off-host development. Tick yield of adult females fed on pigs and rabbits was 81.2% and 58.3%, respectively. Females fed on pigs had mean engorgement weight of 862.3 mg and egg mass of 208 mg, while females fed on rabbits had mean engorgement weight of 606.1 mg and egg mass of 160 mg; these values did not differ statistically between host species. Feeding period of female ticks fed on pigs (10 days) was significantly shorter than that on rabbits (17 days). Mean preoviposition period was slightly longer (35.9 days) for ticks fed on pigs than on rabbits (30 days). The minimum incubation period of eggs of ticks from both host species was similar and over 100 days. Egg production efficiency was low for females fed on both hosts (less than 30% and 20% for ticks from pigs and rabbits, respectively). More than 55% of larvae and 79% of nymphs fed on rabbits, set free inside the feeding chambers, engorged successfully. These ticks attained an engorgement weight of 1.3 and 18.2 mg, respectively, and fed for approximately 5 days. The minimum pre-molt period was 30 days for engorged larvae and over 44 days for nymphs. Molting success was low, less than 50% in the case of larvae and less than 20% for nymphs. Further studies are required to better determine the off-host requirements of this tick species. © 2008 Springer Science+Business Media B.V.

Influence of the environment on behavior patterns of laying hens kept in cages

The aim of this paper is to verify the correlation between environmental indicators and behaviors expressed by laying hens kept in cages. The birds react to a severe environment through their behaviors, end the behaviors can be monitored to identify the birds' welfare conditions. The behaviors birds display ere the result of stress caused by the combination of environmental temperature, relative humidity, radiant heat, and air speed (environmental temperature being the most important). In order to check the influence of the environment, an experiment was carried out on a commercial poultry farm, located in the city of Bastos. The study was initiated in March 2007, during four non-consecutive weeks. The birds' behaviors were recorded using video, by cameras installed in the cages. The birds behaviors were identified and noted for the frequency of occurrence for each bird, and the average duration of each behavior (in seconds), using video samples of 15 minutes recorded from 1 PM to 4 PM. The environmental variables collected were: air temperature, concentration of ammonia, relative air humidity, velocity of the air, noise, roof temperature, and light intensity. The observed behaviors were: opening wings, stretching, threatening, ruffling feathers, drinking water, aggressive pecking, eating, running, lying down, stretching head out of the cage, preening, mounting and prostrating. Principal Components Analysis was used to determine associations between the behavior variables and environmental variables described above. In this experiment, there were no significant correlations between behavioral variables and environmental variables.

Monitoring chronic physical stress using biomarkers, performance protocols and mathematical functions to identify physiological adaptations in rats

This study was undertaken to characterize the effects of monotonous training at lactate minimum (LM) intensity on aerobic and anaerobic performances; glycogen concentrationsin the soleus muscle, the gastrocnemius muscle and the liver; and creatine kinase (CK), free fatty acids and glucose concentrations in rats. The rats were separated into trained (n =10), baseline (n = 10) and sedentary (n=10) groups. The trained group was submitted to the following: 60 min/day, 6 day/week and intensity equivalent to LM during the 12-week training period. The training volume was reduced after four weeks according to a sigmoid function. The total CK (U/L) increased in the trained group after 12 weeks (742.0±158.5) in comparison with the baseline (319.6±40.2) and the sedentary (261.6+42.2) groups. Free fatty acids and glycogen stores (liver, soleus muscle and gastrocnemius muscle) increased after 12 weeks of monotonous training but aerobic and anaerobic performances were unchanged in relation to the sedentary group. The monotonous training at LM increased the level of energy substrates, unchanged aerobic performance, reduced anaerobic capacity and increased the serum CK concentration; however, the rats did not achieve the predicted training volume.

Blood Cues Induce Antipredator Behavior in Nile Tilapia Conspecifics

In this study, we show that the fish Nile tilapia displays an antipredator response to chemical cues present in the blood of conspecifics. This is the first report of alarm response induced by blood-borne chemical cues in fish. There is a body of evidence showing that chemical cues from epidermal 'club' cells elicit an alarm reaction in fish. However, the chemical cues of these 'club' cells are restricted to certain species of fish. Thus, as a parsimonious explanation, we assume that an alarm response to blood cues is a generalized response among animals because it occurs in mammals, birds and protostomian animals. Moreover, our results suggest that researchers must use caution when studying chemically induced alarm reactions because it is difficult to separate club cell cues from traces of blood. © 2013 Barreto et al.

Genetic and non-genetic effects on calf vigor at birth and preweaning mortality in nellore calves

The objective of the present study was to evaluate the genetic and non-genetic effects that influencevigor at birth and preweaning mortality in Nellore calves. A total of 11,727 records of births that occurred between 1978 and 2006, offspring of 363 sires, were analyzed. Poor calf vigor at birth (VB) and preweaning mortality divided into stillbirth (SB), early mortality (EM) and total mortality (TM) were analyzed as binary variables. Generalized linear models were used for the evaluation of non-genetic effects and generalized linear mixed models for genetic effects (sire and animal models). The incidences were 4.75% for VB, 2.66% for SB, 5.28% for EM, and 7.99% for TM. Birth weight was the effect that most influenced the traits studied. Calves weighing less than 22kg(females) and less than 24kg (males) were at a higher risk of low vigor and preweaning mortality. Preweaning mortality was higher among calves born from cows aged .3 and .11 years at calving compared with cows aged 7 to 10 years. Male calves presented less vigor and higher preweaning mortality than female calves. Selection for postweaning weight did not influence preweaning mortality. The heritability estimates ranged between 0.01 and 0.09 for VB, 0.00 and 0.27 for SB, 0.03 and 0.17 for EM and 0.02 and 0.10 for TM. Stillbirth should be included as a selection criterion in breeding programs of Nellore cattle, alone or as part of a selection index, aiming to reduce preweaning mortality. © 2013 Sociedade Brasileira de Zootecnia.

Comportamento, produção e qualidade do leite de vacas Holandês-Gir com climatização no curral

This study was conducted with the objective to evaluate the duration of exposure of animals to the evaporative cooling system in the waiting barn on the weather variables (temperature and relative humidity), animal behavior, production and quality aspects of milk from Girolando cows. Sixteen multiparous lactating cows were used having a genetic composition of 7/8 Holstein-Gir and mean milk production of 18 kg animal-1day-1. A 4 × 4 Latin square design was used. The experiment was conducted during the summer season (February-March 2009) and lasted 56 days. The treatments consisted of different periods of 10, 20 and 30 minutes of exposure to acclimatization and control. Time of 30 minutes of exposure to thermal conditioning system enabled the second milking (evening shift), providing an increase in milk production in the next milking of 0.640 kg animal-1. A higher percentage of time spent on food intake and rumination (17.31 and 30.19%) in 30 minutes treatment, compared to control (15.50 and 27.37%), respectively. There was no significant effect of treatments in the composition of milk.