For most lambs, weaning is one of the most challenging periods in their life. The sudden loss of milk and their mother, change of feed and often separation from their sibling all contribute to a poorer growth rate and weaning check.

If lambs are already behind at weaning, they are also more susceptible to worms and nutritional disorders such as “pine”. The solution is not only to manage weaning well, but to prepare lambs well before weaning. Front-loading nutrition during the weeks leading up to weaning helps build resilient, fast-growing lambs that transition more smoothly and maintain their growth momentum.

Early growth is key

As shepherds, we should take advantage of the in-built efficiency of lambs. From birth to weaning, lambs are the most efficient and are often the most profitable, as they’ve had minimal inputs paid for them at this point. Their feed conversion efficiency can be twice that of a longer keep lamb or hogg finished in the new year. Strong lambs have the edge:

• Greater body reserves to withstand the stress of weaning
• Better rumen development, allowing them to utilise grass and more effectively
• Stronger immune function and more resilience overall

Weaning check

For lambs which haven’t reached market by weaning time, usually 90-100 days old, they must be weaned, so ewes can be prepared for the next tupping season. A weaning check happens when lamb growth slows or stops following separation from their mothers. Even on good grass, lambs often don’t eat as much for a few days as they adapt to their new life, often in a new field where they must find the water and shelter and a new group hierarchy is formed.  It’s this reduction in feed intake which leads to issues such as pine and increased risk of higher worm burden, as nutrient intake is reduced.

The heavier and better-conditioned lambs are at weaning, the smaller this setback is likely to be. Maintaining liveweight gains during the first three to four weeks after weaning has a major influence on finishing weights and overall flock profitability, meaning it’s important to reduce stress as much as possible. Strategies include:

• Taking ewes away and leaving lambs in the same field they’re used to for a week
• Avoiding sudden changes in diet by ensuring feed and lick buckets are still accessible
• Keeping groups stable and not separating siblings straight away if possible
• Utilising roughage and digestible fibre to slow rumen throughput. Lush reseed or silage aftermath might be the best ley available, but lush leafy grass passes through lambs quickly, meaning it doesn’t spend enough time in the rumen for key nutrients and minerals to be absorbed

Where Pine fits in

“Pine” is used to describe cobalt deficiency in livestock and often presents itself as rapid weight loss, crusty ears, reduced appetite and pale mucous membranes. Cobalt is needed by rumen bugs to make their own Vitamin B12, which plays a vital role in releasing energy from feed and increasing appetite. If cobalt is lacking, Vitamin B12 is not made in the rumen, meaning it cannot stimulate appetite and therefore lambs don’t eat, making it a vicious cycle!

Managing Cobalt and Vitamin B12

Knowing your farm’s cobalt status is a good idea. The recent Harbro UK-wide grass mineral survey showed grazing only provides around half a newly weaned lambs requirement for cobalt, leaving us at a disadvantage. This means supplementation is essential to maintain normal livestock growth rates. There are several ways to balance deficiencies, including:

• Grass fertiliser with added cobalt
• Creep feed with added cobalt and Vitamin B12
• Mineral lick buckets with added cobalt and Vitamin B12
• Cobalt boluses or mineral drenches with cobalt and Vitamin B12

The best choice will depend on your farm, livestock, system and budget, so speak to your advisor to help decide on the best option for you. The most important thing is to be ahead of weaning as simply treating pine after clinical signs appear often means valuable growth has already been lost and you must play catch up. Offering both cobalt and Vitamin B12 is key, as Vitamin B12 helps correct the problem straight away, while cobalt allows the rumen bugs to start making their own Vitamin B12 which will correct the problem in the long term.

Front loading nutrition

The weeks before weaning provide an opportunity to maximise growth while milk is still available. Fast-growing lambs generally have larger rumens, better grazing behaviours and greater capacity to maintain feed intake immediately after weaning. Consider:

• Maintaining high-quality grazing and reducing competition for the best grazing
• Providing Harbro Lamb Feeder nuts in hoppers or Harbro Feet & Fertility mineral buckets which contain both cobalt and Vitamin B12
• Controlling worm burden and managing foot health

The Bottom Line

Front loading lamb nutrition is an investment which pays dividends throughout the rest of the year. Lambs with good growth rates before weaning cope better with the inevitable stress, experience a smaller growth check and are less likely to succumb to nutritional disorders such as pine, which have a detrimental effect on flock profitability.

Prevention is always more profitable than a cure and building robust, well-grown lambs before weaning is one of the most effective strategies available for maintaining growth, improving animal welfare and maximising returns.