Smart grass management key to good lamb growth
What a difference a year makes. The cold conditions during last year's spring resulted in little or no grass in most places until the second half of May. This year has seen a complete transformation.
Yet, despite poor grass supplies last spring, lamb thrive was relatively good from June onwards. We could very well end up with the opposite effect this year if we fail to control grass management. The key to achieving good lamb growth rates is to provide adequate quantities of highly digestible herbage. The tight grazing last May prevented seed head formation and pastures heading out, thus providing high quality food for the remainder of the season. There is excess grass on some farms at the moment, especially those with low stocking rates. Unless such pastures are grazed tightly down to 4-5cm over the next 3-4 weeks they will become 'stemmy' as the season progresses. As a consequence, feed quality will be reduced resulting in poorer lamb intake and performance.
Another consequence of long grass is the increased incidence of lameness, especially scald in lambs. Wet weather will add to this, resulting in a further loss of intake and performance.
Grass is by no means a cheap crop to produce and yet it is the cheapest source of animal feed available. In my own situation, I introduce creep feed to triplet lambs from one week of age and to all lambs when they are six weeks. My rationale for feeding concentrates to the lambs is that I am in an all-sheep situation with a high stocking rate, high weaning rate and I want to have the vast majority of the lambs finished by next October/November. If I was stocked at less than 8-10 ewes/ha I certainly would not be feeding creep to singles or twin lambs.
However, I do think it is important, particularly for those in an all-sheep situation, to train lambs onto meals. Once lambing is finished place a few feeders in the field and a few fills will familiarise enough lambs to get them used to eating meal.
This could be crucial if the grass shortage that is already affecting farms in the eastern half of the country spreads over the coming weeks and your lambs suddenly need supplementary feeding. If they haven't been introduced to meals beforehand, they will not take to them quickly enough to compensate for a grass shortage.
Feeding concentrates to mid-season lambs is only economical where grass is less than 6cm high and even then it is hard to justify feeding more than 250-300g/day.
In addition to offering creep, we forward graze the lambs from about six weeks of age. This is achieved by placing steel creep gates in existing gateways. The fact that the triplets rotate on the better grass ahead of the main group helps to entice the lambs forward. The same can be achieved by grazing a few thin or late-lambing ewes and their lambs ahead in the forward field.