My new neighbor informed me that here in the south we shouldnt drag or spread manure on our fields, and the lack of cold weather means the worms never die. This is totally new to me. I always thought that the heat of summer kills the eggs/larvae… I cannot find any good articles supporting this. ANyone out there have REAL research?
What you say is what my vet told me. I don’t think the cold weather actually kills worm eggs - they just stay dormant until it warms up. But hot dry weather and breaking up the manure and exposing it to the heat/ sun kills off the eggs and certainly the larva. ( I still spread across the pasture where nobody grazes). No articles to cite but I bet Equus, The Horse or Practical Horseman would have this information under parasite control.
I looked all over and nothing specific - hot dry weather kills eggs/larvae, but nothing about hot/humid like we have… not even UF/IFAS had anything I could find…
I don’t know if the humidity would keep the eggs viable or not and I don’t know if temperature determines when they hatch out. If the grass stayed wet I suppose the larva could survive. You would have to study the life cycle of the specific worms to determine under what conditions they could survive. Interesting.
I had the same kinda issue. I thought I’d be ok to pick poop in winter and drag in summer, but reading indicated it was hot/dry weather that inhibits worm hatching/lifecycle. Fairly sure daily rains don’t count as hot/dry, so here I am picking all the poop all the time. I sure would prefer to drag sometimes.
Maybe composting would get it hot enough to then spread? That may be too much work though. And then you might get other critters…
From Penn State Extension:
"Whole-Farm Management Strategies for Equine Internal Parasites
It is best to use multiple management techniques when trying to control internal parasite populations on your horse farm. This can include pasture and facility management, as well as dewormer treatments.
…
Pasture Management
Keeping pastures healthy is important for horse management in general, but especially for internal parasite management as many parasites infect the horses when they consume pasture grasses that have larvae or eggs on them.
1.) Avoid having too many horses and/or other livestock on the pasture at once (overstocking) and overgrazing pastures (grass height becomes shorter than 3 inches). When this happens, horses will begin to graze in the “roughs” of the pasture – areas of taller grass where manure accumulates. They typically avoid grazing near manure, which is where parasite eggs are deposited onto the pasture. But when forage is limited, they may be forced to graze the roughs, and there will be a higher risk of horses ingesting parasite larvae. To prevent this, rotate pastures and have a designated sacrifice lot to promote pasture growth and avoid overgrazing.
2.) Mow pastures regularly (keeping the grass between 4-8 inches tall). This helps to keep pastures healthy during the grazing season. It is also recommended that pastures be mowed at the end of the grazing season before wintertime (no lower than 4" for plant health) to reduce winter survival of parasites. However, it should be noted that some internal parasites are extremely hardy and still can survive through the winter (even in the northeast U.S.), so you can’t expect pastures to be “clean” in the spring. Parasites survive particularly well if they are in fecal balls and under snow, which helps insulate them from the cold.
3.) Co-graze pastures with other livestock, such as cattle or goats, that are not affected by the species of internal parasites affecting horses. This allows the other animals to consume some of the parasite eggs that your horse might eat without causing them any harm, since those species of internal parasites do not affect them. This essentially stops the parasite’s life cycle from continuing. You could either graze the animals together or in a rotational system you could graze them one after the other.
4.) Harrowing pastures to spread and break up manure piles can help reduce parasite loads if done during very hot, dry weather conditions. In the northeast US, we often don’t experience dry heat waves that last long enough to kill parasite larvae on pasture. Therefore, in Pennsylvania horses should be removed from that area prior to harrowing and stay off the pasture for the rest of the growing season. This gives time for the parasites to be exposed to the elements and die before the horses return the following spring." (underline mine)
Something that is not mentioned in the article is how long the parasite larva can survive if it doesn’t find a host. Our practice has been to rotate paddocks, harrow the empty paddock and leave it empty for ~ 4 - 6 weeks. Even without the hot dry weather, exposure to sun and air and lack of a new host should kill off most parasites.
We do also pick paddocks in the winter just because it’s unsightly and it affects the grass. Also, according to the article I quoted above, parasite eggs and larva can live happily for a long time in winter in unharrowed or uncomposted manure.
My vet in Florida told me that parasite larva and eggs do not live long once out in the sunlight and air and that dragging to break up the manure helped expose those larva and eggs to the heat and sunlight that would kill them. Manure decomposes really quickly in the hot months so I just dragged regularly and that was sufficient.
Like @McGurk, I also picked paddocks in the winter when I lived there because the manure doesn’t decompose as quickly and it’s unsightly.
1 Like
Cold alone doesn’t kill strongyle eggs. Not even in Canada.
What DOES kill them is exposure to heat and dryness. And strongyle larva don’t live long without a host when it’s hot enough, but can survive 6-9 months in cooler weather (meaning, dragging and resting paddocks in <85* does not reduce the risk of infection)
I rarely have a need to drag in the Summer because dung beetles are making quick work of piles. Sometimes I have to hunt down piles to put the fly predators in.
I DO have to drag in the Winter, when it’s dry enough, which is actually the worst time to do it as it spreads eggs, BUT, it works on our farm, as attested to by regularly clean FECs
The AAEP parasite page is a good one
Internal_Parasite_Guidelines.pdf (aaep.org)
check out Table 5 in particular
Hot and dry kills eggs and infective larva, so it IS best to drag when it’s above 85* to expose more eggs and larva to more heat. They can live a whole lot longer if they’re safely hanging out in/around manure piles
Proper composting to reach high temperature would definitely kill things
It usually rains here every day in summer so I go on and pick up all the piles year round. But if we get a dry spell I might try dragging, though if it’s dry I’ll be irrigating so maybe not.
Thaks, that is what I thought. And thanks for the 85* data - It’s what I needed to know.
