How are this year's lambs growing?
It is easy to generalise but the good weather at lambing time followed by warm dry conditions (less suited to parasites) coupled with the current fantastic grass growth means that the 2017 lamb crop is growing very well at present.
However a few points for your clients to think about:
- The key to low cost lamb production is to get them to slaughter as soon as they reach target weights without significant growth checks.
- The target lamb growth rate from birth to weaning is 280g/day for twins and 380g/day for singles. Knowledge is power so weighing lambs regularly is important.
- Disease can have a significant effect on these growth target growth rates
- For the first 10 weeks of life the majority of a lamb’s feed requirements come from milk.
- After 10 weeks and from now on a lamb’s grass intake will be about 1kg DM per day, increasing by about 100g per week as their diet starts to shift away from milk.
- This natural increase in grass intake, coinciding with the change to wetter conditions this year will increase the worm challenge to lambs.
- Twins and triplets get less milk compared to singles and therefore they have a higher worm challenge.
- Providing low risk grazing and assessing the need for anthelmintics will be more important for multiples rather than single lambs.
- Bear in mind that undiagnosed wormer resistance can reduce weight gain by 50g/day in the absence of clinical signs of parasitic gastroenteritis.
- During the last week at Dumfries we have seen two cases of treatment failure following the use of benzimidazole products.
- A few flocks have also experienced lamb deaths due to infection with large numbers of Nematodirus battus worms. The very warm weather in May will have interrupted the hatch of N. battus eggs which will have resumed when the temperatures dropped back into the 11.5 to 17°C range.
As always the Dumfries Team are keen to discuss flock monitoring and any problem flocks that you might have. Email: OnTheHoof@sac.co.uk