Hardware and software of behavior experiments

One of the areas of experimental physiological research is the study of pain. One of the common pain stimuli used in many laboratories in the world is electric current. In behavioral experiments, a common way of organizing an electrical impact on a moving laboratory animal is to apply electrical voltage to the metal bars of the experimental cage floor. When the animal locks bars with different potential, it receives an electrical shock. It is desirable during the experiment to change the polarity of the electric potential on the bars of the lattice, in order to minimize the ability of the animal to avoid electrical exposure, located on the bars with the same electric potential. The sequence of polarity reversal on metal bars of the cage floor was organized in such a way that not a single pair of bars had the same polarity during the supply cycles of electric current pulses and the animal received an electrical shock at least once per cycle when it closed any pair of bars. Experimental techniques are known in which the voltage applied to the cage floor between adjacent conductive bars is manually controlled by means of a transformer with control of the voltage value on the voltmeter. In this case, the determination of the threshold of pain sensitivity occurs with an error due to a large, manually adjustable pitch of change in electrical voltage. In a number of experiments, it is desirable to provide a more accurate setting of the minimum values of the voltage level and the registration of the current value characterizing the minimum pain sensitivity threshold, as well as to ensure accurate repeatability of the steps of voltage level variation in different experiments with different animals. In order to exclude the possibility for animals to find equipotential bars of the cage floor to avoid electrical shock, for example, they apply electric stimulation independently to each conductive bar of the cage floor, providing a multiphase pulse repetition mode. For accurate and effective determination of the pain threshold of laboratory animals, the device MD280 was developed and implemented. Each electronic key in the device is connected to a specific register bit, and each bar of the cage floor is connected via an electronic key to a controlled constant-voltage source. In turn, the register and voltage source are connected to a control unit connected to the computer via a USB controller. In addition, the device provides correct information by eliminating the possibility of an animal avoiding electrical impact by implementing control of the pulse feed sequence with adjustable phasing (set by the time shift of the pulses on the conductive bars of the floor) and by fixing and saving the measurement sequence at each step of changing the parameters. Interaction with the device is carried out using a computer with USB 2.0 Full-Speed. Data exchange with the PC via the USB interface is performed by a USB-FIFO converter implemented on an FT245RL (FTDI) chip and a block that converts data from the FIFO buffer into internal commands and records data into the FIFO buffer from the device. The program RatCage has been developed, which provides, on the basis of the device, a study of the threshold pain sensitivity of rats. The graphical interface of the program allows at the start of work to select the parameters of the experiment: electrostimulating effects (constant, pulsed, phased, etc.), setting the values of the impact parameters (voltage amplitude, pulse duration, frequency), how parameters change (automatically or manually). After the start of the measurement signal is applied, the voltage amplitude gradually increases. The experimenter observes the behavior of the laboratory animal (rat) and when the primary nociceptive reaction (startle) appears, presses the “Remember” button. The program allows you to save these values along with the experiment protocol in the experimental database. This ensures an effective measurement of the minimum pain sensitivity threshold due to the smooth adjustment of the parameters of the electrical effect pattern (amplitude, duration, frequency of impulses, their number), automatic measurement of parameters when an animal’s primary nociceptive reaction occurs, and also the avoidance of the possibility that the animal avoids electrical impact by feeding electrical pulses with phasing. The developed approach and the implemented tools have been used in pain studies conducted at the I.P. Pavlov Institute of Physiology RAS.

Keragaan Produksi Ayam Broiler Pada Berbagai Metode Pemberian Pakan dan Tipe Lantai Kandang

The aim of this study was to determine the effect of the restriction of feed and the type of cage floor as well as its interaction to production performance in broiler chickens. This study will use 100 DOC (Day Old Chick) day old which consists of 90 major research and an additional 10 to see the state over crowded. The treatments consisted of two factors: The first factor restrictions on feeding consists of: (1) Without limiting the feed (ad libitum), (2) Restrictions feed 15%, and (3) skip a day (feeding hoses one day). The second factor is the type of cage floor consists of: (1) Floor-type wire cages (cage), and (2) Floor type cage litter. The result of this research showed that ad libitum, restricted feeding 15% and skip a day feeding were significantly (P £ 0.01) influence to final body weight, body weight gain, feed consumption kumulatif, and feed conversion. While type cages and interaction were no significantly (P ³ 0.05) on all variable production of broiler chicken.

Quality and chemical composition of eggs affected by rearing system and hen's age

The aim of this study was to evaluate the effect of rearing system and hen's age on quality and chemical composition of eggs. The tested rearing systems were: cage, floor and organic (30 birds Isa Brown hybrid per group). Fifteen eggs per group were collected for analyses in each of three phases of the productive cycle (32, 48 and 72 weeks hen's age). In these samples were investigated external (egg weight and egg shape index), internal (albumen height, Haugh unit and yolk colour) and chemical composition of eggs (dry matter, minerals, protein and lipids content). The general conclusion is that the egg weight and Roche values were increased, while egg shape index, albumen height and Haugh unit were decreased with hen's age. Organic eggs had higher albumen height and more Haugh units in the 48 and 64 weeks compared to the floor and cage eggs. Yolk colour of the floor and cage hens most dependent on the hen's age, on the other hand - yolk colour of organic hens most dependent on the grass availability at the outlet. Eggs from the organic rearing system had a lower dry matter, proteins and lipid content as compared to the cage system.

Evaluating the voiding spot assay in mice: a simple method with complex environmental interactions

The voiding spot assay (VSA) on filter paper is an increasingly popular method for studying lower urinary tract physiology in mice. However, the ways VSAs are performed differ significantly between laboratories, and many variables are introduced compared with the mouse’s normal housing situation. Rodents are intelligent social animals, and it is increasingly understood that social and environmental stresses have significant effects on their physiology. Surprisingly, little is known about whether change of environment during VSA affects mouse voiding and what the best methodologies are for retaining “natural” micturition patterns. It is well known that stress-related neuropeptide corticotropin-releasing factor is significantly elevated and induces dramatic voiding changes when rodents encounter stresses. Therefore we hypothesized that changes in the environmental situation could potentially alter voiding during VSA. We have examined multiple factors to test whether they affect female mouse voiding patterns during VSA, including cage type, cage floor, water availability, water bottle location, single or group housing, and different handlers. Our results indicate that mice are surprisingly sensitive to changes in cage type and floor surface, water bottle location, and single/group housing, each of which induces significant changes in voiding patterns, indicative of a stress response. In contrast, neither changing handler nor 4 h of water deprivation affected voiding patterns. Our data indicate that VSA should be performed under conditions as close as possible to the mouse’s normal housing. Optimizing VSA methodology will be useful in uncovering voiding alterations in both genetic and disease models of lower urinary dysfunctions.

Technological recommendations in rabbit production

In the last ten years a number of research were done and articles were published in order to improve or change the housing conditions of rabbits. These studies focus on the customer needs and changes in expectations based usually on animal welfare. During farm visits we found that the housing circumstances among those factors which are emphasized individually or jointly appeared in the everyday life of rabbit farming (for example: optimal micro-climate, cage floor space, type of floor, keeping mode, environmental enrichment, etc.). In our work we tried to determine the advantages and disadvantages of each procedure. In many cases it is difficult to create perfect coherence with the ideas of animal rights, animal needs and economic interests of the farmers. The number of results and ideas for implementation of all the correct procedures is so great that it is certainly impossible to keep them a time and place in a single technology. Of course, if the changes are generated by the consumer demands, then the farmer has to adapt to expectations in order to keep the market (and sometimes ignoring some other aspects).

Effects of perch on feed consumption and behaviour of caged laying hens

This experiment studied the effects of perches in furnished cages on behaviour and feed consumption of laying hens. The study used 352 Lohmann Selected Leghorn (LSL) hens. The hens were housed at 16 weeks of age in furnished cages in groups of 8 birds. The experiment lasted for 205 days. The treatments were: perches present from 16 weeks of age (P16), perches present from 19 weeks of age (P19), and no perches present (NP). Feed consumption and egg production were measured over the pre-laying period and six 4-week laying periods. The number of hens on perch, in nest and litter box was recorded at various ages. The behaviour of 3 hens per treatment was observed using instantaneous sampling at every 5 minutes, so that the observations of each hen covered one light period (14.5 hours). The treatments had no significant effects on feed consumption after the pre-laying period. Feed conversion ratio (kg feed kg-1 eggs) was favourable in P16 in comparison to NP during the periods 2–4. During the observations after the lights-out NP birds tended to be more frequently in nests, than P16 birds. NP birds spent more time on the cage floor, were recumbent more often, and sitting more rarely in comparison to P16 birds. Based on the results of this study, perches may have advantageous effect on feed conversion ratio in furnished cages.;