Breeding ewe lambs has the potential to increase output but it is a practice that generally requires a higher level of management than dealing with mature ewes. Management decisions taken before and during pregnancy, but especially in the final weeks in the run-up to lambing, can lead to a smoother lambing.

Kildalton College has gained much experience in the area, breeding ewe lambs for several years. Recently, I visited the unit and talked with Kildalton sheep and crops technician Denis Pey to discuss their routine. It is important to note that many management practices taken on the unit are done so for the benefit of teaching students.

The first of these is that the unit breeds ewe lambs to lamb early so that students gain experience with these sheep before they go on practical work experience. This is opposite to most farmers who generally breed ewe lambs later in the year, usually after the main flock.

Breeding

As ewe lambs are bred early they are sponged and given PMSG to help bring lambs cycling cut also to tighten the lambing spread. In 2010, ewe lambs were sponged on September 2 with rams introduced on September 16. All lambs were also shorn, a practice that stimulates increased intake (to generate heat) and therefore gives a boost in growth rate.

In addition, shearing has the benefit of having ewe lambs cleaner during housing and, with less wool, facilitates easier suckling of lambs.

Denis explains that reaching target weights is critical as breeding early gives ewe lambs less time to gain weight. The average weight of ewe lambs going to the ram last year was 52kg to 53kg.

Replacements

All potential replacements are selected at birth. Denis maintains records of all ewes in the flock on their breeding background and also if they have experienced previous problems.

The desired breed is a Belclare/Suffolk combination with a Suffold ram mated to ewes with a high percentage of Belclare breeding and vice versa.

Their genotype for scrapie resistance is also a selection characteristic (ARR type 1). Charolais and Texel rams are used as terminal sires but with less frequency. All potential replacements are identified and marked at birth. For the early lambing flock, this means tail docking possible future breeders and leaving the remainder un-docked.

Performance is then monitored regularly and the best performers and most suitably bred lambs are selected before lambs are drafted. Poor performers can be culled and slaughtered.

Mid-pregnancy management

All sheep are housed from November 15-20 onwards as paddocks are closed to deliver a grass supply in spring. Ewe lambs are ran on good grass from mating to housing to have them in good shape going indoors. Some condition is usually lost during the housing period so the objective is not to have sheep starting from a low point. Once housed ewe lambs are fed on good-quality silage ad-lib.

Late pregnancy management

Denis says that the most important factor to get right to reduce problems at lambing is to feed the correct supplementation rates in the final weeks of pregnancy. A mistake is often made of feeding below the required nutritional levels in mid-pregnancy and then trying to compensate by increasing supplementation rates to similar levels as required by mature ewes in late pregnancy.

This will only serve to give rise to over-sized lambs and lambing difficulties. Similarly, under feeding ewes before lambing will also result in weak lambs, poor milk yield and increased labour.

Ewe lambs are fed according to litter size. Singles receive a flat rate feeding level of 0.25kg with twins receiving 0.3-0.4kg. Triplet bearing ewes are penned with thin ewes where 0.5kg is fed in a split feed morning and evening.

Denis explains how body condition is monitored frequently and if ewe lambs are losing too much condition then feeding levels may be increased slightly. This may also include feeding extra soya bean in the last two to three weeks pre-lambing. He comments that the extra feed required should not be seen as an additional cost but instead as a management practise that will pay dividends by ensuring ewes have sufficient colostrums and milk at lambing.

This is critical to minimise the labour requirement but also to get lambs off to a good start. In 2009-2010, the average weight of lambs born from ewe lambs was 4.13kg from a litter size of 1.55 lambs per ewe lamb. The scanning rate of the 2010/2011 crop is detailed in Table 1.

Management post lambing

Post lambing, ewe lambs are moved to individual lambing pens until a strong bond is developed between the ewe and her offspring and also until lambs are hardy enough to re-enter group pens. Triplet lambs are cross fostered onto single bearing ewes or ewes which may have lost a lmab. The length of time sheep remain indoors depends on the weather and grass supply.

If grass is limiting and weather is poor, the duration may rise to a week to ten days but the aim generally is to get lambs outdoors as soon as they are a few days old.

The ewe lambs are ran as a separate flock to mature ewes in a mixed grazing system with beef cattle or replacement heifers. In previous years, meals were fed to ewe lambs post lambing, plus lambs were creep fed until weaning. The level of supplementation fed to ewes depends on grass availability. Twin bearing ewes are generally weaned earlier at about 12 weeks of age to take the pressure off ewe hoggets and give them a chance to recover.

As with all aspects of the sheep enterprise, he repeats that regular monitoring and a flexible attitude is central to strong performance. If individual ewes are under severe pressure, a decision may be taken to wean earlier where lambs are eating sufficient creep.

Lambs slaughtered from ewe lambs in 2010 averaged 278g average daily gain or an average weaning weight of 26.9kg at average days to weaning of 83 days.

It is worth noting that the range varied from 50 days to 100 days with later lambing sheep weaned at a similar time to the remainder of the flock to prevent any set back in subsequent performance and have sheep at their target weight and condition for the following years breeding.

Disease control

Hygiene is considered critically important in the Kildalton unit to minimise the risk of disease. Ewes and lambs are moved to individual pens for a period after lambing.

Pens are frequently cleaned, washed and disinfected to prevent the build up of infection. In addition hydrated lime is applied before fresh straw is spread and again at regular intervals to further limit the risk of infection occurring. Lime is also used regularly along feed barriers and in group pens.

Ewe lambs receive two injections of a clostridial vaccine in September/October to build full immunity to clostridial diseases and then receive a booster pre-lambing so that passive immunity is transferred to lambs via colostrum and milk. Lambs are also dosed for worms and fluke following Fecpak counts.

This article was first published in the Irish Farmers Journal on 26 February 2011.

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