Getting the most of silage at lambing

Dylasau Uchaf are keen to reduce their reliance on bought in concentrate feed, specifically for their 350-380 flock (number dependent on scanning results) of crossbred mules and Welsh mules around lambing. 

Tupping begins on the 25th of September and lambing commences on the 25th of February.  Currently, they bring their crossbred ewes indoors 8 weeks pre lambing and feed 18% Crude Protein (CP) concentrates and big bale silage in ring feeders. 

The project intends to better utilise the silage/haylage produced on farm by sampling the forage to be fed and therefore provide a diet based on the stage of pregnancy, number of lambs the ewe is carrying and ewe body condition score. Comparison of the cost of production will demonstrate the benefit of growing and harvesting a good grass silage crop.  

The project will also contribute to the Sustainable Land Management outcomes including:

• Reducing Greenhouse gas emissions
• High Animal Health and Welfare 

Key results:

• Improved lamb birth weights and colostrum density was seen from feeding higher quality silage pre-lambing.
• No cases of common neonatal diseases (e.g., diarrhoea, navel infections) were noted.

Background: 

Dylasau Uchaf is a 300-acre upland farm with 800 ewes and 175 cattle. The farm aimed to improve lambing performance, focusing on optimising lamb weight and reducing mortality through strategic nutrition and health management, whilst making best use of conserved forage.

Purpose of the work:

• To improve the utilisation of conserved forage in order to minimise additional bought in inputs while improving lamb weight and reducing mortality.
• Manage ewe body condition, parasites, and infectious diseases to optimise lambing outcomes.
• Improve colostrum quality and lamb birth weights by feeding better-quality silage pre-lambing.

What we did:

• Managed ewe body condition pre-tupping to a score of 3.5-3.0 and pre-lambing to 2.5-3.0.
• Conducted strategic faecal egg counts and targeted worming and liver fluke treatments.
• Vaccinated against clostridial diseases and pasteurellosis, and tested for Toxoplasma gondii.
• Analysed silages and targeted higher quality forage to twin-bearing ewes.
• Supplemented with a commercial concentrate feed based on metabolic blood profiles indicating protein gaps.
• Monitored colostrum quality using a Brix refractometer and lamb weights at birth.

Outcomes:

• No ketosis or neonatal diseases such as diarrhoea, joint-ill, or watery mouth were observed in 2024.
• Groups with a higher silage ME/CP ratio (11.5/13.7) have higher lamb weights. For example: Singles in good condition weighing 4.67 kg and twins in good condition weighing 4.28 kg.
• Groups with a lower silage ME/CP ratio (10.4/11) have slightly lower lamb weights:   Twins in good condition weighing 3.71 kg.
• Higher silage ME/CP ratios are also linked to better colostrum quality: Twins in good condition have 41% colostrum Brix with the higher silage ratio.
• Lower silage ME/CP ratios lead to lower colostrum quality: Twins in good condition with the lower ratio have 32% colostrum Brix.
• Concentrate feed provided closer to lambing (e.g., 0.3 kg one week before lambing) supports better lamb weight and colostrum quality: 0.3 kg concentrate results in 4.28 kg lambs and 41% colostrum Brix.
• Less concentrate feed is linked to lower lamb weights and colostrum quality: 0.15 kg concentrate results in 3.71 kg lambs and 32% colostrum Brix.
• While concentrate feed improves lamb weight and colostrum quality, higher silage ME/CP ratios have a more significant impact.

Table 1: The feeding history of different groups of sheep and their associated mean colostrum brix results and lamb weight results.

How to apply on your farm:

• Monitor and manage ewe body condition using a standardised condition scoring system.
• Analyse forages to establish quality and target feeding to ewes depending on body condition, multiple carrying ewes and stage of pregnancy. Supplement with concentrates to close energy and protein gaps where necessary.
• Test for parasitic infections (e.g., liver fluke) and vaccinate for common diseases.
• Use tools like a Brix refractometer to monitor colostrum quality and provide supplementation when needed.