Further testing at Moelogan Fawr

Scanning results 2023

The ewes were with the rams for two full oestrus cycles (5 weeks) in the autumn of 2022. Scanning for 2023 was very similar to 2022 but barren rate was above the target of 2% for the Welsh ewes at 4.5%, and for the two tooth ewes at 8.6%. This could be attributed to the very dry summer and the potential restriction of growth rate of the young ewes and perhaps not meeting the 80% of mature body weight target by tupping. 

Water testing

Two samples of water were taken from the farm, one from a tap in the farm yard, fed from a spring which supplies the sheep and cattle sheds (Buarth), and the other from a lake that supplies the grazing fields (Llyn). 

*Water analysis interpretation for livestock Univ of Alberta (2007). 

The samples were generally within the acceptable limits for water suitable for livestock. However, there were two elements of note:

• the high copper in the Buarth sample (could potentially cause toxicity in sheep in particular – although the level in the Llyn sample was low and given the animals are only housed for a short period this is unlikely to cause any problems).  It is important to consider all sources of copper when supplementing to avoid toxicity. 
• the high iron in the Llyn sample (this could reduce palatability and cause staining)

Mineral and trace element analysis of six grass samples (24/8/21) 

Fresh grass samples were taken in August 2021 and submitted for mineral analysis. 

The results showed low zinc levels (could be related to lameness), low iodine levels in winter and high sulphur levels (which could affect copper availability). 

Zinc is important in wound healing, skin integrity and horn and hoof growth but deficiency is rare in the UK. 

Iodine is a key element in thyroid hormone function and control of metabolic rate. It is also essential, together with selenium, in mobilisation of brown fat in new-born lambs helping to avoid hypothermia in the first few hours of life. It plays a key role in fertility and health. 

Copper, although adequate for sheep in these samples but below target for cattle, is involved in many enzyme systems in the body. It is essential for fertility (initiating oestrus) and energy metabolism in livestock. A key deficiency symptom is swayback in lambs since copper is also involved in nerve development. Its availability is negatively affected by high levels of sulphur, molybdenum and iron.  

Ewes were all given a bolus (including copper in early October). 

Focus on ewe nutrition pre-lambing

Silage analysis 2022

Ewe rations 

It has been normal practice on the farm to graze ewes on swedes until about 2 weeks before lambing, then move them inside to lamb on a silage and compound diet. This has worked very well in the past and ewes have lambed down with good quality colostrum and plenty of milk. For the indoor ration the diet has been based on ME, FME, ERDP and DUP of 10.4 MJ/kgDM, 8.4 MJ/kgDM, 82 mg/kgDM and 18.4 mg/kgDM respectively. 

Silage intake was estimated at around 1.6% of body weight – or 1.1kg of silage dry matter (2.5kg fresh weight for 70kg ewes) up to the last week before lambing then perhaps a slight drop in silage intake to about 1.0 kg dry matter or 2.2 kg fresh weight. There is a risk when feeding swedes that ewes will be short of protein in the last 3 weeks before they lamb. 

70 kg ewe requirements for energy (MJ/day). 

Compound feed allowances with ad-lib silage. 

Ideally the compound feed needs to be 19/20% crude protein. Once feeding more than 0.5 kg then spilt into two feeds either end of the day. Any thinner ewes will need to be fed for one more lamb than they are carrying. 

Metabolic profiles

Blood samples were taken from ewes on 21/2/23 at about 4 weeks before lambing to assess adequacy of the diet when ewes were grazing swedes. Body condition score of singles averaged 2.4 (2.0 to 3.0) and for twins was 2.8 (2.25 – 3.5). Hence BCS was on average below target for that stage of pregnancy. 

Bloods were tested for:

• BOHB – beta-hydroxybutyrate – an indicator of energy status.  
• Urea – an indicator of rumen degradable protein intake
• Albumin – an indicator of longer-term protein nutrition and underlying health problems. 
• Magnesium – an indicator of magnesium sufficiency
• Copper – an indicator of potential copper toxicity or deficiency

Prolonged insufficient intake of ERDP can affect rumen function, colostrum and milk production and foetal growth. Likewise low albumin is an indicator of subsequent low lamb survival. 

Results (University of Edinburgh 21/2/23) – 17 ewes tested, 10 twins and 7 singles. 

It is clear from the results that all ewes were short of rumen degradable protein whilst grazing swedes which is not surprising given the low protein content of swedes at 9.5% crude protein in the dry matter. There was also an indication that longer term protein supply was also limiting given that blood albumin was below the target of 30g/l. Hypalbuminaemia can originate from various conditions and chronic fluke could be one cause. As the ewes had already been treated for liver fluke on 5/1/23 with closantel (Flukiver) it was advised that faecal samples would be useful to assess the efficacy of the treatment. If concurrent disease such as endoparasitism, lameness or scab can be ruled out, it is likely that the low albumin levels are a result of a low protein intake in the early winter. Ewes were vaccinated against footrot (Footvax) on 8/2/23. 

Sian and Llion were advised (28/2/23) to move the ewes from the swedes onto the silage-based diet with compound feed or to grazed grass to improve protein intake quickly. Ewes were housed on 5 March. 

Barren ewes tested negative for Border disease and Johne’s but one of the 8 ewes was positive for toxoplasmosis. 

Kate Phillips, March 2023