On Monday I wrote about the unusual weight loss as our ewes go into this fall’s breeding groups. Within a few hours of that posting, my vet, Rik, returned my call and we came up with an idea of what might be unfolding and also a plan of attack. I’m so lucky to have found a vet who is willing to work with me as an equal, putting his book-learning and his experiences together with what I have observed and learned about my flock over the years. It is only through this type of teamwork that a flock gets the best medical care, and I am so very appreciative!
Rik and I discussed the flock’s measured weights and reviewed this year’s management based on last year’s parasite issues. I assured him that our sheep were not showing signs of heavy parasite loads, only poor body condition reflected by lower weights on the scale. There is no observable anemia, scouring (diarrhea), weakness or illness. The only other symptom is that they are being marked only very slowly by the rams in their groups. But that may not be an issue, since we’re still very early in the breeding season. I have three marked ewes — not as many as I would expect five days into breeding, but better than we had on Monday.
As we talked about the many things that can impact condition of sheep (how thin or fat a sheep might be), the likely cause of this case of poor body condition began to emerge. Regular readers will recall that early in the grazing season, we kept our flock on only two of our pastures, letting the others lie dormant to eliminate the parasites that had become so heavy on our acreage last year. Around July 1, we dewormed the flock and then put them out on the fields that had not yet been grazed, leaving the two pastures we’d used in spring without sheep for the rest of the grazing season. Cleaning our fields of internal parasites in this way obviously worked well, since with the exception of the whole-flock deworming, we’ve only had to deworm two lambs this summer.
Yet it is exactly this management that may have led to our thin sheep. By the time our sheep went out onto pastures in July, those fields were quite overgrown. Such mature pasture growth is low in protein — and protein was just what many of these ewes needed to rebuild after the heavy weight losses of gestation and lactation. After they grazed these overmature fields, I mowed each of the pastures to allow fresh growth to come in. But the weather was not kind to my sheep — by midsummer, the rain dried up and we slipped into what is now a moderate drought, preventing the lush pasture growth that we usually see. I hadn’t realized that pasture regrowth during drought is also low in protein, once again failing to provide the necessary nutrition for my sheep’s recovery from gestation and lactation. The problem, we believe, is that my sheep have been lacking the protein necessary to regain what they lost in delivering and raising their lambs.
The impact of the flock’s low weights will likely be reflected in lower fertility. One of the solutions to breeding thin ewes is something called “flushing.” This tactic provides a higher level of nutrition just before and during breeding, which triggers the ewe’s body to produce more eggs during her heat cycle. We don’t usually flush our ewes, because flushing mainly works when the girls are thin — and our ewes are normally in pretty good condition at this time of year. Now, however, flushing makes sense. If I continue to provide that higher level of nutrition for a while, they may actually regain much of the needed weight before next spring’s lambing. As a result, I’ve ordered a ton of our grain blend to be delivered later today so that I can begin to flush the flock during the coming weeks.
This new plan harbors possible complications. Gestation requires us to increase the level of nutrition in the last trimester. I’ll have to carefully consider how much grain the flock will get now and for how long in order to avoid grain overload once we get to the final trimester increase. On the other hand, it’s obvious that my flock needs more than they can get in our fields this year. Their condition would not be considered bad if it were May or June — but it’s September, and with breeding season upon us, they can use the extra protein and energy that the grain blend will provide. This is something that I will continue to keep an eye on, and I’ll let you know how it goes.