A Simple Guide to Ewe Nutrition in Late Pregnancy (105-147days)
by Carole Youngs
It’s almost impossible to over-emphasise the importance of ewe nutrition in late pregnancy. The last 6 weeks of pregnancy accounts for approximately 70% of the lamb’s growth, as well as the ewe’s udder development. Good nutrition at this stage will also affect the quality of the ewe’s colostrum and thus the level of energy (to protect against hypothermia) and immunity to disease that she will pass onto her offspring. It’s been estimated that poor nutrition accounts for 20% of all lambing losses, so it’s well worth making sure you get it right.
First Course: Forage
Forage – preferably hay, but haylage (wetter than hay, but drier than silage) and silage are both suitable for feeding to sheep – will provide the main bulk of the ewes’ diet. If it’s good quality, it can also provide much of the energy and nutrients that the ewe requires at this time, so it’s well worth having your forage analysed.
DID YOU KNOW?
- A ewe will eat approx. 2 small hay bales per month during late pregnancy
- Never feed mouldy forage or poorly fermented silage as it can cause listeriosis
- Don’t be tempted to overfeed the ewes, as this can lead to prolapse
There are a couple of vital statistics that you need to know about your forage:
- DM – Dry Matter – this indicates the ‘bulk’ that is essential for good rumen function, a DM of around 85% is normal for hay. For silage it should be in the region 23-30% (avoid any that is considerably lower than these values), and for haylage around 60%
- ME – Metabolisable Energy – this measures the feed value available to the ewe that is not lost in faeces, urine or rumen gases, and the higher the ME value of your forage, the less concentrates you’ll need to feed. Good quality hay will have an ME value of 8.5-10, and for silage look for 9.5-10.5
Not only can feeding top quality forage reduce the level of concentrates you’ll need to feed to maintain a healthy pregnancy, but it will also help rumen function by keeping it at the optimum level of acidity (pH6). Ewes fed high levels of concentrates will typically have a lower (more acidic) rumen pH of around 5, which can lead to acidosis, a condition where the gut microbes are killed off by excess acid. This can lead to dullness, bloat, and in extreme cases, death of the affected animal.
Your forage analysis will also indicate the presence (or absence) of essential minerals and trace elements that are essential to the health of the ewe and her unborn lambs. Of particular concern are Cobalt, Selenium, Copper, and Iodine – all of which can be supplemented during the last few weeks of pregnancy if found to be lacking in your forage.
Remember that in the final 3 weeks of her pregnancy, the lambs’ growth will restrict rumen capacity so the ewe’s intake of forage will decrease, hence the need to increase her concentrate ration.
Second Course: Concentrate Feeds
Never was the term “Quality not Quantity” more appropriate than for a ewe in her final 6 weeks of pregnancy, and in this case, quality refers to the type of protein you feed her. One of the best quality proteins, that is also readily digestible by ruminants, is Soya, which unfortunately has questionable sustainability as much of this is imported from South America on land that was once rainforest. Much research is underway to find alternatives; sustainable crops (lupins being one that is under consideration) that can be grown more locally, but meanwhile, soya will continue to be the mainstay of high-protein ruminant diets.
By the time the ewe is in the last 3 weeks of her pregnancy, her capacity for feed is much reduced by her growing lambs, so it’s essential that what she eats is of the highest quality. Her need at this stage is for DUP – Digestible Undegradable Protein. Check the labels on bagged feed carefully, or ask the feed company – they should be happy to discuss this with you: look for 18-20% protein, of which a minimum of 5% is DUP. It should deliver upwards of 12.5% ME, with between 4.5-5% oil, and look carefully for ‘Fibre’ and ‘Ash’ content – each should be less than 10% in a good quality feedstuff.
On this diet, the ewe’s immune system will be maintained, and whereas a poorly-fed ewe will shed an increased number of worm eggs in late pregnancy, a well-nourished ewe’s worm egg output will remain low, which means her lambs won’t be challenged by a high level of parasite contamination.
Desert Course: Feed Blocks, Mineral Buckets & Drenches
If you are in doubt about the quality of your forage, or when grass supply is limited, feed blocks and mineral buckets can be a good idea to supplement the energy and protein requirements of the ewes and to supply minerals and trace elements that may be lacking from their diet. However, they are expensive per unit of energy and protein, and there may be a wide variation in the amount each ewe consumes. Make sure you read the labels carefully.
A vitamin and mineral drench is at least guaranteed to reach the spot, so to speak, and you can time the drench for optimal effect, eg. pre-tupping, 4 weeks pre-lambing, and lambs at 8 weeks and at weaning.
So, how can you tell whether all your good work is doing the trick and maintaining your pregnant ewes in peak health towards their due date? At this point, I feel it’s appropriate to hand over to someone who has a great deal more experience of judging the condition of ewes – from commercial breeds to rare breeds …
Sheep on Your Smallholding
Programme 2 - Managing Your Flock for Peak Health
For further sheep breeding information, see 'The Breeding Flock', programme 3 in the series 'Sheep on Your Smallholding'.