Autumn grazing plan: This week’s sheep feature focuses on autumn and winter grazing management. The importance of closing up ground earmarked for early grazing next spring is demonstrated by a quick look at grass demand. A ewe will require in the region of 1.2kg to 1.5kg DM per day at present compared to 2.4kg to 2.5kg DM per day for a twin-suckling ewe turned out to grass 24 to 48 hours after lambing, rising to 3.2kg to 3.5kg DM five weeks into lactation. Therefore, it is critical that ground is closed in sufficient time to have a supply of grass available next spring which in turn will reduce costs and labour.

Teagasc advice on closing targets for flocks operating a mid-season lambing enterprise at a medium-to-high stocking rate (10 to 12 ewes per hectare) is to have 20% of the farm closed by late October, 40% by mid-November, 60% by late November and 80% by mid-December. This will typically provide a rest period of 120 days giving paddocks first closed an opportunity to have a reasonable cover of grass on swards while growth is still relatively good.

For example, under normal grass growing conditions, paddocks closed on 20 October will typically have a cover of 900kg DM/ha to 1,000kg DM/ha in early March or in terms of grazing it will deliver 7.5 grazing days for 50 ewes and their lambs. Swards closed in early November will deliver six grazing days while in contrast a sward closed in late November will deliver 3.7 grazing days and a sward closed on 20 December will deliver just three grazing days.

Farmyard manure: The last day allowable for spreading farmyard manure (FYM) is 31 October, with the prohibited application period starting on 01 November.

FYM cannot be field stored over the winter months and can only be stored under a roof or on a concrete slab where runoff can be collected. The opening period for spreading FYM begins on 13 January in Zone A counties, 16 January in Zone B counties and 1 February in Zone C counties. Farmers in Northern Ireland are governed by the same timeline as Zone C farmers.

Mating targets for ewe lambs: The liveweight of ewe lambs at time of joining with rams has a big influence on its success. The advice coming from years of research highlights that ewe lambs should weigh at least 60% of mature weight at breeding.

Teagasc research on the efficiency of ewe lambs shows that the heavier ewe lambs are at mating, the better the chances are of each lamb mated rearing a lamb. A stipulation to this statement is that ewe lambs should be grown naturally and not excessively fed with concentrates to reach target weights as overfeeding can have negative consequences on health and fertility.

Overfeeding of ewe lambs in early pregnancy can reduce litter size due to damaging interactions with progesterone supply. While underfeeding in early pregnancy is also to be avoided as it will contribute to ewe lambs failing to hit weight targets at lambing and is linked to higher lamb mortality.

Age will also have an influence but the influence of these factors reduces as the year progresses and lambs naturally begin to cycle due to the shortening day length.