Ewe lamb flocks scanned to date are returning positive results for a second consecutive year. Litter sizes in many flocks have actually increased on spring 2014 levels, with average litter sizes of 1.4 to 1.7 lambs not uncommon in flocks using prolific breeds in their breeding programme. Other flocks normally scanning around one lamb have experienced litter sizes increasing by 0.1 to 0.2 lambs, with lower barren rates and a tighter lambing spread also reported in many cases.

Weather in recent months has been hard on mature ewes and has been potentially even harder on ewe lambs where feeding programmes have not taken account of the tough weather. The importance of ewe lamb feeding programmes comes more under the spotlight in late pregnancy due to the rising energy demands of the growing foetus, coupled with already significant nutritional demands for maintenance and for the animal’s own growth.

Higher nutritional demand

The first port of call when developing a late-pregnancy feeding programme is scanning. The optimum time frame to deliver accurate results is between 80 and 90 days post-ram turnout.

Ongoing research by Teagasc’s Tim Keady, based in the Animal and Grassland Research Centre in Athenry, points to a ewe lamb requiring an additional 2.5 megajoules (MJ) of metabolisable energy (ME) during mid- and late-pregnancy (relative to adult ewes of similar weight and at the same stage of pregnancy and litter size) to achieve a daily liveweight gain of 50g per day.

The study explains that the ME requirement of a twin-bearing ewe lamb weighing 55kg in late pregnancy increases by over 50%, or from 12MJ ME to 18MJ ME, in the last six weeks of pregnancy. The energy requirement of single-bearing ewe lambs increases by 30%.

This energy requirement puts huge stress on ewe lambs, especially in the absence of a sufficient diet. Articles in recent weeks from Teagasc Athenry and University College Dublin (UCD) stressed the importance of feeding high-quality, high-energy feeds in late pregnancy to ensure nutritional demands are met and animals give birth to lambs with good vigour while also having adequate colostrum.

The situation is no different for ewe lambs and is possibly more critical for ewe lambs carrying twin and triplet lambs.

As is the case in any multiple-birth pregnancy, access to forage of high dry matter digestibility (DMD) is essential to promote intake and prevent issues associated with low-quality forage, such as twin lamb disease or vaginal prolapse.

Ewe lambs in the Teagasc Athenry trial were offered grass silage of 75 DMD, with supplementation introduced at a rate of 250g/day in late January (mean lambing date of late March). Feeding 250g was continued until late pregnancy feeding kicked in six to seven weeks pre-lambing, with the exception of triplets which had their rate stepped up to 300g daily in mid-February.

This period between mid- to late pregnancy is often a high-risk period for farmers and especially those supplementing outdoors, with grass or forage quality often overestimated, leading to animals stalling or failing to gain condition. Condition lost at this stage will be very hard to recover later down the line and every effort should be made to avoid significant weight loss.

Late-pregnancy feeding

Feeding in late pregnancy in the Athenry trial saw single-bearing ewes receive 18kg concentrate supplementation in late pregnancy, while twin-bearing ewes received 26kg and triplets 33kg. Table 1 details a typical supplementation programme for similar feeding levels.

Where forage quality is limiting, concentrate feeding rates will need to be stepped up to address this. As with all animals, it is recommended to split feeding levels once it exceeds 0.5kg. Care should also be taken to ensure all animals have sufficient feeding space and can eat unrestricted.

With regards to concentrate formulation, the aim should be to target an energy value of 12+ MJ ME. Animals may also have a higher protein requirement than mature ewes to promote growth. This will be influenced by feeding levels and the quality of forage offered, but in general a protein requirement of 15% to 16% is sufficient in mid-pregnancy and the early stages of late-pregnancy feeding, rising to 18% to 20% in the final weeks of pregnancy.

Lactation management

Getting animals to lamb down with good-sized lambs and adequate colostrum is the first half of the battle. Greater care is needed at lambing and in the weeks post-lambing to ensure lactating yearling hoggets are maintained on the right track. Generally, hoggets giving birth to twin and triplet lambs may require a longer bonding or holding period in individual lambing pens. For this reason, it is recommended to have more than the normal recommendation for medium-prolificacy flocks of one lambing pen for every seven to eight ewes.

It is strongly advised to pull one lamb off any triplet-bearing ewe hogget and to monitor ewes suckling two lambs very closely in early lactation.

These hoggets should be managed similarly to triplet-bearing ewes receiving at least 0.5kg concentrate supplementation, along with access to top-quality grass for the first five weeks of lactation. Where grass quality or quantity is limiting, this should be increased accordingly.

Lambs should also be given access to 300g creep daily to weaning stage and likewise have supplementation rates increased if required. Ewes failing to rear lambs should have one lamb removed for artificial rearing.

It is also important to pay particular attention to the health status of yearling lactating hoggets as natural immunity is often delayed due to nutritional stress.