**7.1 General benefits**

Boars are found on most modern pig farms. They are needed to find sows in estrus when AI is used. Below are reasons to not have boars on the farm. The reasons include cost, safety and disease control.

The boar costs money to buy and they cost money to maintain. Besides the direct cost of the boar, the boar does not live a good life. They are heat checking sows often and rarely if ever breed. They are often housed in a crate or stall individually for their own safety and the safety of other sows and boars.

Boars are dangerous to have on farms. One large farm in the USA reported that they budget \$500,000 per year for boar-induced human injuries. The boar can take a single swipe at a person and damage the person severely. If a boar was very aggressive, they could do great damage to a person. While rare, boars sometimes step on people, or bite people or knock them down if a person stands in the way of the boar and his intended direction.

Boars carry disease. While sows move from breeding to gestation to farrowing and back to breeding, the boar resides in the barn for a long time (a year or more). The boar can be a reservoir of disease and continually infect new breeding sows.

When a serious disease (foot and mouth, ASF, etc.) is found in a country, they often limit movement of adults in some or all regions. If the farm cannot get live adult boars, and have no access to pheromones, the breeding rates will be very low.

### **7.2 Pheromone applications in the field**

#### *7.2.1 Sows*

Melrose [35] first suggested Androstenone was the boar pheromone. But we and others have observed that this single molecule was not sufficient to elicit the full sexual behavioral response in estrus sows. This led to the project to seek and discover the complete boar pheromone. This was accomplished by using advanced GC-MS technology to identify three unique molecules that are found in boar saliva and not found in sow saliva [59]. If one examines **Figure 4**, is clear that androstenone alone has only a small effect on sows expressing estrus when they are in fact in heat. But the three molecules together give the largest increase in sow sexual


#### **Table 5.**

*Results from McGlone et al. showing that BOARBETTER® caused an increase in pigs born and born alive in parities 1–3 on 12 farms.*

behavior. Furthermore, data we collected recently showed that most sows identified in estrus by a boar, also express estrus behavior to the three-molecule pheromone called BOARBETTER® (BB).

Boar Better (BB) was formulated to include all three molecules in an analog to the natural pheromone. When BB was applied to 12 USA farms in different USA states on nearly 4000 sows, it was discovered that BB increased Farrowing Rate, and litter size born (total or alive). Together, the increase per batch of pigs was significant—over 8% more pigs born per batch. The effect on early parities (1–3) was greater than for older sows that may have maximized their uterine capacity (**Table 5**). Note that while the overall increase in total pig born per litter was 0.40 more pigs with BB, in parities 1–3, the increase was 0.88 pigs/litter due to BB. This is a remarkable improvement in reproduction that cannot be achieved by any common animal health product on the market.

#### *7.2.2 Gilts*

While we believe and hope that BB is also the priming pheromone that accelerated gilt puberty, we do not have solid data to show that this is the case. These studies are underway now. We know cycling gilts can be bred with BB because it is a powerful releasing pheromone. Still, because the live boar can stimulate the onset of puberty, it is likely that BB is also the priming pheromone.
