Abomasal bloat in lambs & kids

Abomasal bloat is a condition that puts fear into the heart of any lamb rearer. It is one of the leading causes of sudden death seen in young lambs, as well as those around weaning, typically occurring within a couple of hours of a warm milk feed. For the more observant owners out there, you may notice a slow smouldering over a few days as the belly empties slower after each feed.                               

Causes & symptoms

The cause of abomasal bloat is likely multifactorial but essentially, undesirable bacteria in the stomach feed on lactose in the milk (milk’s natural sugar) and produce gas. When the stomach receives large volumes of milk, these bacteria breed quickly, until one day a large milk feed produces so much gas that the stomach stretches irreversible, bloating and killing the lamb.                         

This condition is not seen in naturally reared lambs who drink very small amounts, continuously throughout the day. A one-week-old lamb on the ewe may drink up to 36 times a day! Even at 7 weeks old, when many of our bottle-reared babies are gearing up to wean, they would still be drinking up to 14 times a day from the ewe. Feeding lesser feeds of large volumes, while standard practice, is where our issues stem from.               

Of course, lamb/kid bloat is not always straightforward abomasal bloat, and an ultrasound or x-ray by an experienced small ruminant practitioner can help identify the cause. Other causes include intussusceptions, constipation, gut twists, rumen bloat*, and intestinal infections. If your little one starts bloating, especially if it happens suddenly, this is an emergency and it should see a vet immediately for a thorough work-up.

Prevention                                                                    

• Feeding 10-15% of their body weight (adjust as they grow) divided into as many small feeds throughout the day as you can practically manage.                                                                         
• When held at a 45-degree angle, the teat should drip milk, but not flow. Likewise, cracked or damaged teats can lead to a quick flow, which can lead to Ruminal Bloat*                                                                                
• While the bacteria responsible is yet unproven, there are strong links with some bacteria which are now covered in COVEXIN 10. We recommend vaccinating with COVEXIN 10 from 2 weeks of age.                                                                             
• Offer “creep feed”, which is highly digestible grain, from 5 days old, to help the stomach adjust to grown-up food, to prevent against Ruminal Atony*
• Yoghurtise your milk. Yoghurtising is still the only proven method for the prevention of abomasal bloat. By turning your milk into yoghurt, you are removing the lactose, thereby removing the food source for the bacteria. Check out our website for our easy-to-use recipe.  NOTE: Simply adding probiotic yoghurt to the milk at the time of feeding does NOT prevent bloat, and may increase the risk, as some of the bacteria in probiotic yoghurt are, in fact, gas-producing in themselves.
• Spray-Fo is a new milk product on the market with label claims of reducing the risk of abomasal bloat. It does so by moving the milk through the stomach faster than usual, leaving less time for the nasty bacteria to feast on the lactose. Beware that, although getting everything they need, they will feel hungrier than usual with their quickly-emptying tummies, so free access to grass and creep feed is a must! Get this right and you may notice better growth around weaning as well.     

Dr Sarah Clews (BSc BVSc)                                                                                    

* Ruminal Bloat is when milk spills over from the baby stomach (the abomasum) into the grown-up stomach (the rumen)              

** Ruminal Atony is commonly seen in older animals when there is a sudden change of diet, causing the rumen (the grown-up stomach) to become distended and dysfunctional.