Rodent Control on Poultry Farms

Vineetha P.G., Rekha Mohan and Jeny George
Author’s correspondence:
1. Vineetha P.G., Assistant professor, Dept. Poultry Science (CASPS) KVASU, Mannuthy, Thrissur, Kerala.-680651 e-mail: vinworld06@rediffmail.com, vineethavinu2012@gmail.com
2. Rekha Mohan., MVSc Scholar, Dept. Poultry Science (CASPS) KVASU, Mannuthy, Thrissur, Kerala.-680651
3. JenyGeorge.,MVSc Scholar,Dept. Poultry Science (CASPS) KVASU, Mannuthy, Thrissur, Kerala.-680651
Author: Dr.Vineetha P G
Assistant professor
Dept.Poultry Science (CASPS) – KVASU,Mannuthy
Thrissur,Kerala-680651

Preventive actions against rodent infestations are rarely as vigorous and dedicated as the problem demands. This may be because poultry growers are not aware of the severity of an infestation (due in part to the nocturnal behavior of mice and rats). In addition, a rodent control program must be thorough and must be constantly maintained. Effective rodent control in and around the poultry house involves a four-step process (Loven, 2010): 1. Sanitation 2.Rodent-proof construction 3.Population reduction 4.Evaluation.

The adaptability and agility of rodents make getting rid of them particularly difficult and damage comes in many forms: 

• Damage to buildings – Mice and rats will damage wood and electrical wiring, which can be a fire hazard.
• Destruction of insulation – Many facilities show serious deterioration within five years, resulting in increased energy costs, re-insulation costs and poorer feed conversions by animals.
• Feed consumed- 100 rats will consume over one tonne of feed in one year.
• Feed contaminated- A rat can contaminate 10 times the amount of feed it eats with its droppings, urine and hair. A rat produces 25,000 droppings per year, a mouse 17,000.
• Biosecurity- Rodents are recognised as carriers of approximately 45 diseases, including salmonellosis, pasteurellosis, leptospirosis, swine dysentery, trichinosis, toxoplasmosis and rabies (Donald et al., 2002).

While there are several different types of rodents that can cause problems on farms, the two most common are House mice (Musmusculus) and Norway or Brown rats (Rattusnorvegicus). House mice can vary in color from gray to brown, ranging from 5 ½ to 7 inches long, and weigh up to ½ ounce. Their droppings tend to be small and look like black grains of rice. House mice can live from 5 to 12 months and can start breeding at around 50 days of age. Additionally, they have a gestational period of 19-21 days, and they can begin breeding 14-24 hours after giving birth. This ability to breed at a young age, coupled with a short gestational period can result in mice having from 5 to 10 litters in a year. With an average litter size of six young, a single mother can produce as many as 60 offspring in a year. Norway rats have thicker fur that can range from red to brown-gray with lighter fur on the sides. They are 12 to 18 inches long and weigh around 10 to 16 ounces.Rat droppings are bigger (3/4 of an inch), rounded and bean sized. Rats can breed as young as 3 to 4 months of age and can continue to breed until they are 18 months of age. The gestation period is 21-25 days and the young are weaned three weeks after they are born. After weaning, the females can breed again one day later. Rats can have 4 to 6 litters each year and average nine young per litter. Therefore, under ideal conditions, up to 50 young may be weaned each year.

To control mice and rats, we have to understand their habits and biology first. Mice and rats are similar in their habits and biology, although there are some differences between the two:

• Both are highly reproductive and extremely capable of surviving in all kinds of conditions.
• On farms, mice and rats will be near a food source such as barns, granaries, livestock buildings and silos.
• Rats and mice can climb and jump. Rats can jump vertically as high as 91 cm and horizontally as far as 122 cm.
• Mice and rats can climb brick and other rough walls, and travel along utility wires.
• Rats can cross (sneak in) through openings as small as 1 cm and mice can squeeze through openings of 0.6 cm, or less, in diameter.
• Both mice and rats are active at night, particularly right after dusk. They have a home range of approximately 100 feet and often live in colonies, with several rats sharing the same feed and water source (Berry, 2003).
• Rats are smart and tend to avoid new objects. Therefore, it may take a few days for traps and baits to work.

Afarmer /supervisor needs to be on the lookout for signs of rodent activity. Identify signs of rodent activity by looking carefully around the coop and other areas where birds spend time. A regular cleaning routine will help you detect signs of rodents more easily.The best time to check for problems is to look for rodents at night using a flashlight. Looking for rodents at night will also help determine the degree of infestation, and identify effective areas to place traps.

Some common signs to look for are:

• Rodent droppings;
• Gnawing or chewing marks on feeders or buildings;
• Holes around the coops;
• Strong ammonia smells; and
• Accumulation of leaves, paper, or other things that can be considered as nesting material.

Estimating the rodent population

The presence of rats and mice is not always obvious. However, one rule of thumb for the estimation of rat populations is as follows:

• Rat sign but no rats seen – 1 to 100.
• Occasional rat sightings at night – 100 to 500.
• Seen every night and occasionally by day – 500 to 1000.
• Many by night and day – up to 5000.

 Controlling rodent problem – The cost of controlling rodents is small compared to the losses incurred through rodent infestation. In order to survive, rodents need food, water and shelter. Use the following ideas to help eliminate these three things and minimize rodent intrusion:

• Clean up all spilled feed (make sure feeders are adjusted properly to prevent feed waste and spills), dead birds and broken eggs.
• Store feed in aluminum cans with lids so that rodents can’t access them. Place all bagged food and equipment on a platform about 60 centimetres off the ground and 60 centimetres from any wall.
• Keep grass short (rodents don’t like to cross open areas without cover). Maintain at least a 3-foot space around the perimeter of the poultry house that is free of brush, trash, weeds, and so forth. This will allow to check outside of the building for potential pathways, burrows, and rodent activity.
• Use rodent-proof materials that are hard for rodents to gnaw through such as concrete, galvanized steel, brick and wire mesh.
• Make sure load-out and walk-in doors close and seal properly.
• Check that corrugated metal siding is sealed, and make sure corner seams are tight. Properly seal openings surrounding feed augers, water lines, and electrical conduits that enter the house from outside.
• Elimination of nesting places -Clean up your farm and remove all debris that can provide shelter for rodents.
• If the storage area cannot be rodent proofed, move the material at least every week to prevent rodents from establishing themselves in it.
• Use nipple waterers to make it difficult for rodents to get water.
• Baiting and/or trapping programmes can be adopted.
• Monitoring of rodent populations and practising control measures.

It is important to remember that traps and the bait stations need to be sized for the targeted rodent. If starting a control program for the first time, start baiting before destroying likely nesting areas as part of a cleanup. Destroying nesting areas before baiting and/or trapping will only result in most of the rodents moving elsewhere and not being caught by the programs. If the baiting program doesn’t appear to be working and the population hasn’t changed it may be worthwhile to use a 10 days on, 10 days off baiting program. Rodents are very intelligent and may stop eating bait. If possible, co-locate water with the bait for the rodents to drink. Quite often, they will drink and eat during the same period. If water is not readily available they are likely to leave the bait station to look for water. Baits should be added to once a week or more often if necessary to keep them fresh. Baits should be 1 to 2 metres (3 to 6 feet) apart for mice and 7 to 10 metres (23 to 33 feet) for rats. Remove all uneaten baits and properly dispose of them after the poisoning program. In determining how to control rodents, we also need to consider children, pets, and or wildlife that might come in contact with traps or bait. Take care not to spill the bait where the poultry can have access to it.

Trapping – Traps are another option and should be located on rodent pathways. Snap traps, multiple capture traps, electronic mouse traps and glue boards are among the types of traps available. Each works differently and has its own pros and cons, depending on where it is going to be used. Snap traps and glue boards are relatively low cost and are typically used when dealing with small numbers of mice or in combination with baiting. These traps are easy to find at hardware stores and at most grocery stores. The glue traps are disposable while snap traps can be reused multiple times. Snap traps and glue boards should not be set where pets, children, or free-range poultry can come in contact with them. For larger infestations, multiple- capture trapscan be used to catch large numbers of live mice. Another method used to capture large infestations is Electronic Mouse Traps. These traps are available for both rats and mice. They emit a high voltage shock that kills the rodent instantly and requires no bait. They can kill up to 50 mice using a single set of batteries.

The only disadvantage of trapping is that continuous use of trapping leads to trap shyness (avoidance of traps). However, changing the placement and type of trap, along with the bait type, may be helpful to overcome this problem. Traps should be placed close to the wall, behind objects, or in dark corners where rodents may hide. The number of traps to be placed inside the shed depends on the size of the shed. Bait may need to be placed close to the trigger of the trap to increase the chances of success. Check the traps daily and collect any dead rats/mice and reset the traps.Always record details of the location of traps and the number of rodents caught in the traps. Revise the location of traps to increase trap numbers where they are most effective.

Rodenticides – A wide variety of rodenticides (poison baits) are available. Selecting the right one can be confusing but is a very important task. In most situations, ready-to-use commercial baits are the preferred choice over mix-your-own baits. However, an understanding of the basics is still necessary to know how to use a particular product most effectively and to avoid bait aversion. Rodenticides may be formulated as bar baits, pellets, pastes, concentrates, or tracking powders.

Acute toxicity rodenticides are also called single-dose rodenticides and will kill rodents after one feeding if an adequate amount is consumed. The use of a zinc phosphide compound is helpful when there is a high population of rats. It should be used at a strength of 1 or 2 percent, by mixing one or two parts of the compound with 99 or 98 parts of a feed grain, such as broken rice. A small quantity of vegetable oil must be well mixed through the grain before mixing in the zinc phosphide. About 100 g of bait should be placed at each point along the inside walls of the poultry house. Strychnine is also available in the market but it should be considered for short-term use only as rats and other rodents do not usually accept it. Other acute toxicity rodenticides include red squill (a powder made from the plant Urgineamaritima), alpha-naphthylthiourea and sodium fluoracetate.

Delayed toxicity rodenticides, also known as multiple-dose compounds, have a cumulative effect and will kill rodents after several feedings. Bait has to be available continuously, and other feed sources must be removed. The rate of rodent kill depends on the type of rodenticide and the dose consumed. Some products kill within 1 hour, and others require 4 to 7 days after ingestion. Warfarin (a product containing hydroxycoumarins) is a delayed toxicity rodenticide and is known as a first generation anticoagulant. It is a slow acting poison that reduces the amount of vitamin K in rats. Vitamin K is necessary for blood coagulation. This delayed action poison can be safer than acute toxicity poisons.

Tracking powders are toxic dusts that contain high concentrations of either acute action or delayed action toxicants. These are mostly useful in those conditions where rats avoid traps or refuse to eat the grain bait. Tracking powders can be used in steel or cardboard trays or in protected bait stations. In each bait or tray put the recommended amount of powder and place them along wall 8-10 m apart. When rodents travel through these powder-containing trays they will pick up the powder in their fur and feet, where it is later ingested during grooming. The powder in the tray or bait station should be checked every two weeks and the stations kept in operation throughout the year for effective rodent control.

These rodents can spread disease and cause structural damage to the facilities, resulting in economic losses. Preventative measures, along with traps and rodenticides, can lessen the likelihood of rodents becoming a problem. If rodents are in and around your poultry operation, use a safe and aggressive rodenticide and trapping program to eliminate them. When developing a rodent control program, make sure that it does not harm children and non-targeted animals.

References

1. Berry, J. 2003. Rodent control in the poultry house. Publ. No. ANSI-8207. Oklahoma Cooperative Extension Service. Oklahoma State University.
2. Donald, J., M. Eckman, and G. Simpson. 2002. How to control rats, mice, and darkling beetles. Poultry Engineering, Economics, and Management Newsletter. No. 20. November. Auburn University.
3. Loven, J. 2010. Controlling rodents in commercial poultry facilities. Publ No. ADM-3-W. Purdue Cooperative Extension Service. West Lafayette, IN.