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My ewes are due to lamb starting on March 15th. Next week I’ll start adding grain to their diet, to support them during the last month-long push of their pregnancies and into the first few weeks of nursing. And, I have just over a ton of hay left. So, today was “math day” to assess my feed plans between now and when the grass is ready to graze and the lambs are eating on their own.

Grass is Good

Grain feeding is controversial now that grass-fed is all the rage. There are pro’s and con’s to both arguments. But this is another area where I’m sitting on the fence and not inclined to go to either extreme.

On one hand, grass-feeding is most natural for ruminants. A diet that’s very high in grain can stress ruminant health, because it doesn’t push enough roughage through the rumen to have it function optimally. And, there is the argument that a flock that can raise young productively on grass alone is worth its weight in gold- the Holy Grail of low-input systems.

Grain is Better (I think?)

On the other  hand, these ewe are being pushed hard. I expect almost all my ewes to have twins or triplets. I expect them to feed all their lambs all by themselves with no supplemental creep feed. And I expect the lambs to show rapid weight gain. This is an extraordinary demand on a ewe- much more than nature would ever ask. Though deer and other wild ruminant species often twin, it’s still not the same. The wild animal growth rate is very moderate compared to meat animals, which we have bred for reaching market weight very fast, and for high milk production. 

When ewes are carrying twins and triplets, in the last weeks of pregnancy, those fetuses  start to consume a lot of abdominal space. They compress the ewe’s stomach, so she can only take in so much feed before she feels full. Feeding twice or three times a day helps, but even then, a pure hay diet will challenge the ewe’s ability to take in more calories than she’s expending. Not only is there risk of her losing condition at an undesirable rate and being stressed, her life and the viability of her lambs is at stake if she develops pregnancy ketosis or milk fever from chronic underfeeding.

These arguments have me convinced there is value in supplementing ewes with some grain during late pregnancy and early lactation (up to 50/50 ratios are supposed to be OK). So I’m sticking closer to old-school sheep husbandry convention in this regard.

The Strategy

Here’s my plan for this spring. I am using dry COB for my grain source- “dry” meaning no molasses, and COB stands for corn-oats-barley. It is a fairly inexpensive ration, and I prefer the whole or cracked grain source (rather than ground-feed sheep rations) because it’s supposed to be better for the rumen. I also don’t want any mineral additives in the feed right now, because of my separate experimentation with that issue.

I fed COB last year to my ewes too, but I did things a bit more willy-nilly- I mostly eyeballed and estimated and just went by how much hay the sheep cleaned up each day. They had access to grass most of the winter. And I had no idea when most of them were due to lamb, so it was hard to follow a set schedule. It all worked out fine, but it might not have. Also pre-buying feed becomes more important with more animals, both for cost savings as well as reduced work. So this year I want to do more math and also keep better records for future reference.

Sources I’ve found cite that you can “swap” COB-style grain for average-quality hay at about a ratio of 1.8 to 1. So, 1 lb of grain can replace 1.8 lbs of hay to give the ewe the same amount of calories/energy. At the same time, I’m increasing their overall mass intake to meet the increasing demands of the lambs.

I plan to make changes in five-day increments, to give the sheep time to gradually adjust. So, I’ll start out with 1/2 lb of grain per head per day, then increase by 1/4 lb per head every five days until they are at 1.5 lbs per day. By then, they should be eating about 5-6 lbs of feed total per head per day, so the hay is still comprising 70% or more of their diet. I’ll leave them there for about twenty days, then start decreasing the grain back down in 1/4 lb increments. This takes them through about the first month of nursing. After that, the grass will be fairly voluminous and nutritious. And, the lambs will be starting to take in enough of their own nutrition that the peak milk demand is over for the ewes.

Number Crunching

All while this is being done, care  must be taken to make sure the ewes don’t get overfed. Fatness can encourage uterine prolapse, and big lambs that are harder to deliver. So, I can’t just throw unlimited feed out there and let the ewes completely pork out. So, this ends up being quite a bit of mathematical figurin’ to try to get it right! And there is certainly more than one idea of how it should be done.

For instance, if you have the luxury of doing ultrasound exams on the ewes, you could separate those with twins and triplets and feed them more. I suppose the cost of doing ultrasound might be offset by the feed cost savings, and lowered risk of single-carrying ewes getting over-conditioned.

But not only do I lack access to this technology, I also have ewes that range in size quite a bit, and two rams and a llama mixed in who get to enjoy pregnancy feeding too. 😉 And of course the ewes will lamb over the course of more than two weeks, some getting the benefit of early graining more than others. So, they all have to suffer the law of averages and the laws of competitive eating. I’m sure that some ewes will not be optimally fed in one direction or the other. But doing the math still helps to strive towards ideal.

I’ve worked it all out in an Excel spreadsheet. It makes it easy to do the calculations of per-day increases and decreases, the ratios of grain to hay, and total feed needed. I can print out the feeding schedule to follow as I measure their intake each day, and take notes in my electronic file for future reference if anything doesn’t go as planned. Here is what the schedule looks like through the end of April.

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At some point, I’ll be weaning them off of hay as the grass volume becomes adequate and they can go back into rotation. Of course, I won’t know when this is until it happens! But, we’ve had such unreasonably warm weather, the grass is already growing some now. So I’m optimistic that this will be an early year for spring grazing. As it turns out so far, I have almost exactly the right amount of hay. So, for once, the sheep read the manual and are doing just what it says! 😀

How do you like to feed your ewes and does during pregnancy and lactation?

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