ANSC 103 Working with Farm Animalst
By Richard Cobb
Needles have evolved over the years so that today they come in many different sizes and diameters, or gauges. Needles also have different bevels on the tip to better do the jobs they are used for. Gauges run from 4 to 30 , with the smaller number being the largest around. A four gauge needle would be used to insert an t6rocar with a 10 gauge used to place a catheter in a jugular vein of a cow. On the other end of the scale a 30 gauge needle would be used by a dentist to give you Novocain before drilling your brains out. The most commonly used gauges of needles in domestic animal production would be in the 16 to 22 range with 18 the most common. Use an 18-gauge needle for small volume doses - less than 10 cc. Use a 16 gauge for large volume doses of 10 cc or greater.
Needles of course come in different lengths. When drawing blood from pigs you will be using a needle that is 6 inches long! Drawing blood from the neck of a sheep or the tail vein of a cow is usually done with a 1 inch needle. For intramuscular injections a 1 inch needle is commonly used with young animals while a 1.5 inch needle would be used in adults. For subcutaneous injections a .5 to 1 inch needle is favored.
The viscosity of the product also plays a part in gauge selection. If the product is "thick" and pushes through the needle hard, opt for the 16 gauge needle even for the small dose. If selecting one needle for all-around performance, a 1-inch, 16 gauge needle works well. Its a good all around needle that meets the requirements of intramuscular and subcutaneous injections. When using needles for injections it is best to change them every 10 to 15 injections, or each time you stop to refill an automatic syringe. Dull needles cause excess issue damage. which increases the chances of reactions and abscesses forming. Also, over used needles can become dirty and spread germs. Never just throw away used needles. They need to be stored in a "sharps" container . This is a plastic box used to store needles until they can be properly disposed of. Often timer you veterinarian can or a local hospital or the local public health office can remove and replace your container for you.
Syringes also have evolved over the years. Today there are many sizes and shapes of syringes. Many are specialized, or used for just one thing. Basically there are just two types though. Syringes that are made to be disposed of after one use, and those that are made to be used many times.
Disposable syringes are in theory used only one time and then discarded. The syringe used to draw blood from a human probably falls under this description. However, plastic, disposable syringes are the backbone of many livestock producers health programs.
Automatic or re-usable Syringes. are made to be used for many years . They must be maintained with proper cleaning and storing if they are to do so however.
When processing domestic animals, all injections and vaccinations should be given under the skin in the neck region using the tenting technique. To use this technique the producer grips the skin with his/her fingers and lifts the skin upward. This creates a space between the skin and the muscle of the animal. The needle is inserted in this space and the injection is made.
Abscesses showing up in the rump and round or leg or ham of carcasses at slaughter plants are mostly due to injections given when the animal is young. All of these could have been eliminated if the proper procedures had been followed at time of vaccination.
A small lump in the neck is unsightly but a hidden abscess is totally uncalled for. Lumps in the neck region are normally attached to the hide and not the carcass itself.
A clean pan with a disinfectant soaked sponge is the best way to keep needles clean. Do not vaccinate wet animals as there is a greater chance of causing abscesses if the hide is wet.
Poultry receive less shots than the other species we are involved with. Most treatment of poultry is done by fogging entire building so that the birds inhale the product, or by treating the water the birds drink.. Some birds are given injections however, using a "wing stab" technique or with a 23 gauge needle directly into the body cavity of the bird.
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