Common Flies and the Impact on a Herd
There are three common types of flies that can be found near livestock and in pastures: horn flies, face flies, and stable flies.
HORN FLIES
Horn flies lay their eggs in livestock manure and their eggs can hatch in as little as eighteen hours from laying. Their average life span is ten to fourteen days. In just its short lifetime though, horn flies can cause loss of livestock weight, obstruct grazing patterns, and infection of other diseases. Horn flies are blood feeders and typically feed off cattle thirty to forty meals per day. They can overtake a herd in a very short time due to their quick reproduction rate.
FACE FLIES
Face flies lay their eggs in livestock manure as well. Their eggs take approximately two to three days to hatch, but they only live an additional two to three days after hatching. Face flies damage the eyes and facial aspects of the cattle. Not only can they tear up their coat, but they spread pink eye most often. If pink eye is a consistent problem within your herd, face flies are probably the culprit. Although face flies mainly disrupt the facial areas of the cow, it can also reduce nursing to a calf as the cows feel more stress with a high concentration of face flies and tend not to nurse as frequently.
STABLE FLIES
Stable flies lay their eggs in wet organic matter such as wet hay or winter hay feeding sites. Stable flies are also blood feeders and tend to effect the front legs of the livestock. Stable flies cause the cattle to bunch up, reducing the areas which are grazed. This impacts not only the nutrition to the cattle, but also the nutrition to the pastures. Cattle will also stomp around burning more calories than they are able to consume due to the decrease in grazing time or area. Standing in water is another impact, which not only can lead to a reduction in nursing time for young calves, but also a reduction in grazing time for the cattle. Also foot rot can become an issue if too much time is spent in the mud of the ponds, rather than allowing their hooves to compact dry ground.
All flies and parasites cause a disruption in grazing creating less gain on cattle and a lower profit gain for the ranch or production company.
Fly control has many different methods of attack on this predator. The most common being the following:
- Feed additives- these can be inconclusive as it does not effect adult flies and they will migrate to areas where food additives are not put out. It can also be ineffective as it is impossible to control the amount each cow consumes and if not enough is consumed, it will not work.
- Sprays- these can be effective in certain situations, however, they do have to be applied every two to three weeks which can be economically ineffective
- Pours- these are the almost the same case as the sprays. They have to be administered usually every ten days. Typically they are more inexpensive than the spray ons, but economically can negatively impact the business depending on size and goals of the company.
-Ear tags- These are a cost effective way to maintain fly control, however, usually flies will build up resistance to these methods.
