WHY ANIMAL FAT OR ANIMAL PROTEIN REPELLENTS WORK BEST?
There are basically two types of deer repellents that are worth considering. The rest are either largely ineffective, or just ridiculous! Repellents containing animal proteins or slaughterhouse waste are proven to be the most effective - and that's backed by field research.
Decaying animal protein or animal fat is repulsive to herbivores and the avoidance of these odours is a FEAR RESPONSE, suggesting that herbivores perceive sulphurous odours as indicators of predator activity. In the presence of air or light the protein or fat will oxidise and give off sulphurous odours. That's how nature works. If there's a squashed hedgehog or cat on the road then it'll stink for a month or more, then start to fade. After 2-3 months the odour is neutralised, and the source becomes desiccated. This is just a natural process.
SYSTEMIC REPELLENTS
Systemic repellents are compounds absorbed by the plant, rendering the foliage less desirable. Systemic delivery is ideal in theory - the repellents are contained within the plant and cannot be washed off, and the aversive agents are moved to new foliage as it grows. However, few, if any, products have effectively incorporated repellents into a plant at concentrations that did not harm the plant! But systemic repellents are practically useless because they rely on the pest having a decent chew to get the supposedly bad chemical taste...but by then it's too late as the plant is stuffed. What's the point then? As you know, all it takes is a nip off the top of growth points and the tree either dies or is distorted, and this can set it back years, or it might die. So these types of repellents are a waste of time and are as useless as coffee grounds, orange peels, garlic, soaps, essential oils, etc.
REPELLENTS BASED ON PAIN OR TASTE
This is based on the idea of 'conditioned avoidance' which can occur when ingestion of a food is paired with nausea or gastrointestinal distress. Animals generally don’t eat as much
of a food if it is associated with illness. But capsaicin/peppers/bittering agents/hot sauces or other repellents based on a pain or taste response are ineffective because, as above, the deer have to eat the tree to get a decent taste, then the tree is buggered. Efficacy of repellents based on conditioned avoidance is generally limited because animals must be trained to avoid these materials. Damage inflicted on seedlings during training or subsequent sampling can be extensive. Repellents based on training are also not likely to be effective for a transitory or migratory species.
FEAR BASED REPELLENTS
The BEST approach is to stop browsing herbivores from having a chew in the first place - hence why fear-based repellents are the ONLY solution - and that's based on published research! The pest MUST be deterred BEFORE chewing the plant! Research proves that egg-based or blood-based repellents work well to deter these pests, but they only offer protection for about 1-2+ months maybe a bit more depending on ambient conditions.
Our BANGBANG repellent is an animal protein-based repellent: BLOOD + EGG + FISH protein - and so offers 3-way repellency. We add a bit of ANIMAL-FAT as a sticker-spreader on the plant thereby enhancing resilience and rainfastness. The fat coating clings to the plant and offers a longer protection profile than other animal protein products. It is a potent deer and rabbit repellent that also offers NPK benefits for plant growth and health.
Our FATBANG is emulsified animal-fat and offers 3-6 months protection, depending on ambient conditions. Optimal protection will occur in the first 3 months. Anecdotal feedback from some commercial clients suggests that a 6-month protection profile can be achieved on forestry redwoods.