[Experimental animals]-Feeding and management of experimental rats

  In principle, the management of rats is the same as the management of rats. Special attention should be paid to the following.

  1. Environmental conditions

  Rats are very sensitive to environmental factors. Fluctuations and sudden changes in temperature and humidity may be important sources of stress and easily promote the development of conditional pathogen infections. If the air is dry and the humidity is lower than 40%, the rats are more susceptible to scurvy. Dirty and overcrowded bedding, poor ventilation in cages, and excessive ammonia or hydrogen sulfide in the environment can cause respiratory infections and large lungs. Local inflammation, especially the development of mycoplasma; rats are sensitive to hearing and have poor tolerance to noise. Strong noise can cause eating and smoking.

  Hikari has a great influence on the reproductive physiology or behavior of rats. Even within the recommended standard light level range, strong ambient light can cause retinal degeneration and cataracts in rats with albinism. A light barrier must be installed in the upper rat cage to prevent the ceiling illuminator from affecting the rat. During the experiment, it is forbidden to use insecticides to spray animals or the breeding environment to prevent changes in the animals' bodies and adversely affect the results of the experiment. Overfeeding will slow down weight gain, increase the type and density of intestinal pathogens, and cause significant changes in plasma hormone levels in rats.

  In short, the rat breeding room should be quiet, ventilated and clean.

  2. Cage and garbage

  The size of the bottom of the squirrel cage must be large enough to have enough space to move the mouse. In addition to meeting the requirements of national standards, the fragments used on rats should also be disinfected. More importantly, controlling physical properties such as dust debris can cause foreign body pneumonia in rats.

  Some surgical animal bedding needs to be replaced every day to prevent experimental complications. Some animal toilets that use isotope experiments must be treated in accordance with relevant regulations on radioisotope pollutants.

  3. Eating and drinking

  Rats have the habit of eating at any time and usually need to eat enough food 2 to 3 times a week. Rats have higher requirements for protein (especially animal protein and vitamins), and the dose is larger than that of mice. Rats are very sensitive to malnutrition, which usually leads to undernutrition and aggravates the development of infection. In addition, special soft feed ingredients or feeds, such as sunflower seeds or multi-dimensional tablets, should be prepared according to the requirements of the experimenter.

  Clean grade rats can use acidic water with pH 2.5-2.8, and SPF grade rats must use autoclave or purified water. The ratio of food to water consumption for rats is 1:2. Therefore, to eat 1 gram of feed requires 2 ml of water, and sufficient drinking water is required.

  4. Hygiene and disinfection

  Due to the limited space in the mouse box, you need to change the toilet twice a week. In addition, the ammonia, hydrogen sulfide and other irritating gases in rat feces are very important for feeding. Workers and animals are harmful irritants and easily cause respiratory diseases. Feces are microorganisms. This is also an ideal breeding place. If it is not replaced in time, it is likely to cause animal contamination. Garbage replacement must be carried out on a dedicated work vehicle or ultra-clean workbench. The method is the same as the mouse. After replacing all the cages, the cages and dirt should be removed from the breeding room in time and treated without any harm. Improve work efficiency and meet rat hygiene needs. The replaced mouse box should be rinsed with water, dried and disinfected before use, but the drinking bottle and cork should be cleaned and disinfected before use.

  Before entering the breeding room and starting work, the staff will strictly implement the barrier environment emergency management procedures, while maintaining the integrity of the indoor environment, doors and windows, walls, floors, mouth boxes and shelves, and aseptic operations. You must strictly follow the principles. It should be scrubbed in time to keep it dust-free. Use 0.1% new ceramics or other disinfectants every Tuesday and Friday, change the type of disinfectant every other week, and perform a major disinfection once a month. 0.2% peroxyacetic acid has an excellent spray disinfection effect.

  The litter, feed, mouse box, beverage bottle, etc. are autoclaved and placed in the washing preparation room for storage. Various cooking utensils and items are stored in fixed locations and arranged, organized and used in fixed partitions. After use, it should be cleaned and disinfected for storage time. Must not exceed 15 days.

  If you suspect an infectious disease or zoonotic disease due to breeding or experimentation, please ask your veterinarian to check and take measures.

  5. Observe and record

  Observe the rat’s food, water intake, activity level, whether there are gods in the eyes, the color of the tail, etc., and record it in time, and then record it later.

  The production record of each box of breeding mice includes the name of the strain, group, number, birthday, mating date, production date, parity, number of litters, weaning date, weaning day (♀♂), etc. Must be recorded.

  Weaned mice need to record the strain name, group, date of birth, parity, weaning frequency (♀♂), parent number, etc.

  Experiment records include observation results of daily animal experiments, animal activities, spirit, fur, feed and water intake, feces, room temperature, humidity, pressure difference, animal death, etc. The records are accurate. The above records should be reported to the experiment host every day, and the team leader should report twice a week.

  Work records usually include date (year, month, day, week), weather (maximum and minimum temperature, meteorological conditions, etc.), indoor environment (room temperature and humidity, pressure difference, ventilation, etc.), and work plan (morning and afternoon) included in Inside. , Completion status, questions, notes, etc.

  6. Production index

  The

  production index indicates how many weaned piglets can be produced by each animal in the group on a specific day. Due to different biological characteristics, different types of laboratory animals have different production indexes. Due to different conditions and management methods, different groups in the same inventory have different production indicators. After learning how to calculate the production index, it can predict the productivity of the herd, provide scientific basis for production and supply planning, cost calculation and budget, and is of great significance to scientific research. The calculation method is as follows.

  Production index = number of heads (♀) × productivity × number of litters × weaning frequency / number of heads (number) productivity = number of heads produced (♀) / number of heads (♀)